1/* 2** 2001-09-15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef SQLITE3_H 34#define SQLITE3_H 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Provide the ability to override linkage features of the interface. 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51#ifndef SQLITE_API 52# define SQLITE_API 53#endif 54#ifndef SQLITE_CDECL 55# define SQLITE_CDECL 56#endif 57#ifndef SQLITE_APICALL 58# define SQLITE_APICALL 59#endif 60#ifndef SQLITE_STDCALL 61# define SQLITE_STDCALL SQLITE_APICALL 62#endif 63#ifndef SQLITE_CALLBACK 64# define SQLITE_CALLBACK 65#endif 66#ifndef SQLITE_SYSAPI 67# define SQLITE_SYSAPI 68#endif 69 70/* 71** These no-op macros are used in front of interfaces to mark those 72** interfaces as either deprecated or experimental. New applications 73** should not use deprecated interfaces - they are supported for backwards 74** compatibility only. Application writers should be aware that 75** experimental interfaces are subject to change in point releases. 76** 77** These macros used to resolve to various kinds of compiler magic that 78** would generate warning messages when they were used. But that 79** compiler magic ended up generating such a flurry of bug reports 80** that we have taken it all out and gone back to using simple 81** noop macros. 82*/ 83#define SQLITE_DEPRECATED 84#define SQLITE_EXPERIMENTAL 85 86/* 87** Ensure these symbols were not defined by some previous header file. 88*/ 89#ifdef SQLITE_VERSION 90# undef SQLITE_VERSION 91#endif 92#ifdef SQLITE_VERSION_NUMBER 93# undef SQLITE_VERSION_NUMBER 94#endif 95 96/* 97** CAPI3REF: Compile-Time Library Version Numbers 98** 99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100** evaluates to a string literal that is the SQLite version in the 101** format "X.Y.Z" where X is the major version number (always 3 for 102** SQLite3) and Y is the minor version number and Z is the release number.)^ 103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105** numbers used in [SQLITE_VERSION].)^ 106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107** be larger than the release from which it is derived. Either Y will 108** be held constant and Z will be incremented or else Y will be incremented 109** and Z will be reset to zero. 110** 111** Since [version 3.6.18] ([dateof:3.6.18]), 112** SQLite source code has been stored in the 113** <a href="http://www.fossil-scm.org/">Fossil configuration management 114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115** a string which identifies a particular check-in of SQLite 116** within its configuration management system. ^The SQLITE_SOURCE_ID 117** string contains the date and time of the check-in (UTC) and a SHA1 118** or SHA3-256 hash of the entire source tree. If the source code has 119** been edited in any way since it was last checked in, then the last 120** four hexadecimal digits of the hash may be modified. 121** 122** See also: [sqlite3_libversion()], 123** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124** [sqlite_version()] and [sqlite_source_id()]. 125*/ 126#define SQLITE_VERSION "3.35.5" 127#define SQLITE_VERSION_NUMBER 3035005 128#define SQLITE_SOURCE_ID "2021-04-19 18:32:05 1b256d97b553a9611efca188a3d995a2fff712759044ba480f9a0c9e98fae886" 129 130/* 131** CAPI3REF: Run-Time Library Version Numbers 132** KEYWORDS: sqlite3_version sqlite3_sourceid 133** 134** These interfaces provide the same information as the [SQLITE_VERSION], 135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136** but are associated with the library instead of the header file. ^(Cautious 137** programmers might include assert() statements in their application to 138** verify that values returned by these interfaces match the macros in 139** the header, and thus ensure that the application is 140** compiled with matching library and header files. 141** 142** <blockquote><pre> 143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146** </pre></blockquote>)^ 147** 148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149** macro. ^The sqlite3_libversion() function returns a pointer to the 150** to the sqlite3_version[] string constant. The sqlite3_libversion() 151** function is provided for use in DLLs since DLL users usually do not have 152** direct access to string constants within the DLL. ^The 153** sqlite3_libversion_number() function returns an integer equal to 154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155** a pointer to a string constant whose value is the same as the 156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157** using an edited copy of [the amalgamation], then the last four characters 158** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159** 160** See also: [sqlite_version()] and [sqlite_source_id()]. 161*/ 162SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163SQLITE_API const char *sqlite3_libversion(void); 164SQLITE_API const char *sqlite3_sourceid(void); 165SQLITE_API int sqlite3_libversion_number(void); 166 167/* 168** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169** 170** ^The sqlite3_compileoption_used() function returns 0 or 1 171** indicating whether the specified option was defined at 172** compile time. ^The SQLITE_ prefix may be omitted from the 173** option name passed to sqlite3_compileoption_used(). 174** 175** ^The sqlite3_compileoption_get() function allows iterating 176** over the list of options that were defined at compile time by 177** returning the N-th compile time option string. ^If N is out of range, 178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179** prefix is omitted from any strings returned by 180** sqlite3_compileoption_get(). 181** 182** ^Support for the diagnostic functions sqlite3_compileoption_used() 183** and sqlite3_compileoption_get() may be omitted by specifying the 184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185** 186** See also: SQL functions [sqlite_compileoption_used()] and 187** [sqlite_compileoption_get()] and the [compile_options pragma]. 188*/ 189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191SQLITE_API const char *sqlite3_compileoption_get(int N); 192#else 193# define sqlite3_compileoption_used(X) 0 194# define sqlite3_compileoption_get(X) ((void*)0) 195#endif 196 197/* 198** CAPI3REF: Test To See If The Library Is Threadsafe 199** 200** ^The sqlite3_threadsafe() function returns zero if and only if 201** SQLite was compiled with mutexing code omitted due to the 202** [SQLITE_THREADSAFE] compile-time option being set to 0. 203** 204** SQLite can be compiled with or without mutexes. When 205** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206** are enabled and SQLite is threadsafe. When the 207** [SQLITE_THREADSAFE] macro is 0, 208** the mutexes are omitted. Without the mutexes, it is not safe 209** to use SQLite concurrently from more than one thread. 210** 211** Enabling mutexes incurs a measurable performance penalty. 212** So if speed is of utmost importance, it makes sense to disable 213** the mutexes. But for maximum safety, mutexes should be enabled. 214** ^The default behavior is for mutexes to be enabled. 215** 216** This interface can be used by an application to make sure that the 217** version of SQLite that it is linking against was compiled with 218** the desired setting of the [SQLITE_THREADSAFE] macro. 219** 220** This interface only reports on the compile-time mutex setting 221** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223** can be fully or partially disabled using a call to [sqlite3_config()] 224** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226** sqlite3_threadsafe() function shows only the compile-time setting of 227** thread safety, not any run-time changes to that setting made by 228** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229** is unchanged by calls to sqlite3_config().)^ 230** 231** See the [threading mode] documentation for additional information. 232*/ 233SQLITE_API int sqlite3_threadsafe(void); 234 235/* 236** CAPI3REF: Database Connection Handle 237** KEYWORDS: {database connection} {database connections} 238** 239** Each open SQLite database is represented by a pointer to an instance of 240** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243** and [sqlite3_close_v2()] are its destructors. There are many other 244** interfaces (such as 245** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246** [sqlite3_busy_timeout()] to name but three) that are methods on an 247** sqlite3 object. 248*/ 249typedef struct sqlite3 sqlite3; 250 251/* 252** CAPI3REF: 64-Bit Integer Types 253** KEYWORDS: sqlite_int64 sqlite_uint64 254** 255** Because there is no cross-platform way to specify 64-bit integer types 256** SQLite includes typedefs for 64-bit signed and unsigned integers. 257** 258** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260** compatibility only. 261** 262** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264** sqlite3_uint64 and sqlite_uint64 types can store integer values 265** between 0 and +18446744073709551615 inclusive. 266*/ 267#ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269# ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271# else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273# endif 274#elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277#else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280#endif 281typedef sqlite_int64 sqlite3_int64; 282typedef sqlite_uint64 sqlite3_uint64; 283 284/* 285** If compiling for a processor that lacks floating point support, 286** substitute integer for floating-point. 287*/ 288#ifdef SQLITE_OMIT_FLOATING_POINT 289# define double sqlite3_int64 290#endif 291 292/* 293** CAPI3REF: Closing A Database Connection 294** DESTRUCTOR: sqlite3 295** 296** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297** for the [sqlite3] object. 298** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299** the [sqlite3] object is successfully destroyed and all associated 300** resources are deallocated. 301** 302** Ideally, applications should [sqlite3_finalize | finalize] all 303** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 304** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 305** with the [sqlite3] object prior to attempting to close the object. 306** ^If the database connection is associated with unfinalized prepared 307** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 308** sqlite3_close() will leave the database connection open and return 309** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 310** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 311** it returns [SQLITE_OK] regardless, but instead of deallocating the database 312** connection immediately, it marks the database connection as an unusable 313** "zombie" and makes arrangements to automatically deallocate the database 314** connection after all prepared statements are finalized, all BLOB handles 315** are closed, and all backups have finished. The sqlite3_close_v2() interface 316** is intended for use with host languages that are garbage collected, and 317** where the order in which destructors are called is arbitrary. 318** 319** ^If an [sqlite3] object is destroyed while a transaction is open, 320** the transaction is automatically rolled back. 321** 322** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 323** must be either a NULL 324** pointer or an [sqlite3] object pointer obtained 325** from [sqlite3_open()], [sqlite3_open16()], or 326** [sqlite3_open_v2()], and not previously closed. 327** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 328** argument is a harmless no-op. 329*/ 330SQLITE_API int sqlite3_close(sqlite3*); 331SQLITE_API int sqlite3_close_v2(sqlite3*); 332 333/* 334** The type for a callback function. 335** This is legacy and deprecated. It is included for historical 336** compatibility and is not documented. 337*/ 338typedef int (*sqlite3_callback)(void*,int,char**, char**); 339 340/* 341** CAPI3REF: One-Step Query Execution Interface 342** METHOD: sqlite3 343** 344** The sqlite3_exec() interface is a convenience wrapper around 345** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 346** that allows an application to run multiple statements of SQL 347** without having to use a lot of C code. 348** 349** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 350** semicolon-separate SQL statements passed into its 2nd argument, 351** in the context of the [database connection] passed in as its 1st 352** argument. ^If the callback function of the 3rd argument to 353** sqlite3_exec() is not NULL, then it is invoked for each result row 354** coming out of the evaluated SQL statements. ^The 4th argument to 355** sqlite3_exec() is relayed through to the 1st argument of each 356** callback invocation. ^If the callback pointer to sqlite3_exec() 357** is NULL, then no callback is ever invoked and result rows are 358** ignored. 359** 360** ^If an error occurs while evaluating the SQL statements passed into 361** sqlite3_exec(), then execution of the current statement stops and 362** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 363** is not NULL then any error message is written into memory obtained 364** from [sqlite3_malloc()] and passed back through the 5th parameter. 365** To avoid memory leaks, the application should invoke [sqlite3_free()] 366** on error message strings returned through the 5th parameter of 367** sqlite3_exec() after the error message string is no longer needed. 368** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 369** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 370** NULL before returning. 371** 372** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 373** routine returns SQLITE_ABORT without invoking the callback again and 374** without running any subsequent SQL statements. 375** 376** ^The 2nd argument to the sqlite3_exec() callback function is the 377** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 378** callback is an array of pointers to strings obtained as if from 379** [sqlite3_column_text()], one for each column. ^If an element of a 380** result row is NULL then the corresponding string pointer for the 381** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 382** sqlite3_exec() callback is an array of pointers to strings where each 383** entry represents the name of corresponding result column as obtained 384** from [sqlite3_column_name()]. 385** 386** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 387** to an empty string, or a pointer that contains only whitespace and/or 388** SQL comments, then no SQL statements are evaluated and the database 389** is not changed. 390** 391** Restrictions: 392** 393** <ul> 394** <li> The application must ensure that the 1st parameter to sqlite3_exec() 395** is a valid and open [database connection]. 396** <li> The application must not close the [database connection] specified by 397** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 398** <li> The application must not modify the SQL statement text passed into 399** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 400** </ul> 401*/ 402SQLITE_API int sqlite3_exec( 403 sqlite3*, /* An open database */ 404 const char *sql, /* SQL to be evaluated */ 405 int (*callback)(void*,int,char**,char**), /* Callback function */ 406 void *, /* 1st argument to callback */ 407 char **errmsg /* Error msg written here */ 408); 409 410/* 411** CAPI3REF: Result Codes 412** KEYWORDS: {result code definitions} 413** 414** Many SQLite functions return an integer result code from the set shown 415** here in order to indicate success or failure. 416** 417** New error codes may be added in future versions of SQLite. 418** 419** See also: [extended result code definitions] 420*/ 421#define SQLITE_OK 0 /* Successful result */ 422/* beginning-of-error-codes */ 423#define SQLITE_ERROR 1 /* Generic error */ 424#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 425#define SQLITE_PERM 3 /* Access permission denied */ 426#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 427#define SQLITE_BUSY 5 /* The database file is locked */ 428#define SQLITE_LOCKED 6 /* A table in the database is locked */ 429#define SQLITE_NOMEM 7 /* A malloc() failed */ 430#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 431#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 432#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 433#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 434#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 435#define SQLITE_FULL 13 /* Insertion failed because database is full */ 436#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 437#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 438#define SQLITE_EMPTY 16 /* Internal use only */ 439#define SQLITE_SCHEMA 17 /* The database schema changed */ 440#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 441#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 442#define SQLITE_MISMATCH 20 /* Data type mismatch */ 443#define SQLITE_MISUSE 21 /* Library used incorrectly */ 444#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 445#define SQLITE_AUTH 23 /* Authorization denied */ 446#define SQLITE_FORMAT 24 /* Not used */ 447#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 448#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 449#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 450#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 451#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 452#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 453/* end-of-error-codes */ 454 455/* 456** CAPI3REF: Extended Result Codes 457** KEYWORDS: {extended result code definitions} 458** 459** In its default configuration, SQLite API routines return one of 30 integer 460** [result codes]. However, experience has shown that many of 461** these result codes are too coarse-grained. They do not provide as 462** much information about problems as programmers might like. In an effort to 463** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 464** and later) include 465** support for additional result codes that provide more detailed information 466** about errors. These [extended result codes] are enabled or disabled 467** on a per database connection basis using the 468** [sqlite3_extended_result_codes()] API. Or, the extended code for 469** the most recent error can be obtained using 470** [sqlite3_extended_errcode()]. 471*/ 472#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 473#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 474#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 475#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 476#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 477#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 478#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 479#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 480#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 481#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 482#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 483#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 484#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 485#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 486#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 487#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 488#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 489#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 490#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 491#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 492#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 493#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 494#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 495#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 496#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 497#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 498#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 499#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 500#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 501#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 502#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 503#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 504#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 505#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 506#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 507#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 508#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 509#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 510#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 511#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 512#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 513#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 514#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 515#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 516#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 517#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 518#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 519#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 520#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 521#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 522#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 523#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 524#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 525#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 526#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 527#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 528#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 529#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 530#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 531#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 532#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 533#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 534#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 535#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 536#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 537#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 538#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 539#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 540#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 541#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 542#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 543#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 544#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 545#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 546 547/* 548** CAPI3REF: Flags For File Open Operations 549** 550** These bit values are intended for use in the 551** 3rd parameter to the [sqlite3_open_v2()] interface and 552** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 553*/ 554#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 555#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 556#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 557#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 558#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 559#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 560#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 561#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 562#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 563#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 564#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 565#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 566#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 567#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 568#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 569#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 570#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 571#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 572#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 573#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 574#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 575 576/* Reserved: 0x00F00000 */ 577/* Legacy compatibility: */ 578#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 579 580 581/* 582** CAPI3REF: Device Characteristics 583** 584** The xDeviceCharacteristics method of the [sqlite3_io_methods] 585** object returns an integer which is a vector of these 586** bit values expressing I/O characteristics of the mass storage 587** device that holds the file that the [sqlite3_io_methods] 588** refers to. 589** 590** The SQLITE_IOCAP_ATOMIC property means that all writes of 591** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 592** mean that writes of blocks that are nnn bytes in size and 593** are aligned to an address which is an integer multiple of 594** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 595** that when data is appended to a file, the data is appended 596** first then the size of the file is extended, never the other 597** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 598** information is written to disk in the same order as calls 599** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 600** after reboot following a crash or power loss, the only bytes in a 601** file that were written at the application level might have changed 602** and that adjacent bytes, even bytes within the same sector are 603** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 604** flag indicates that a file cannot be deleted when open. The 605** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 606** read-only media and cannot be changed even by processes with 607** elevated privileges. 608** 609** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 610** filesystem supports doing multiple write operations atomically when those 611** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 612** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 613*/ 614#define SQLITE_IOCAP_ATOMIC 0x00000001 615#define SQLITE_IOCAP_ATOMIC512 0x00000002 616#define SQLITE_IOCAP_ATOMIC1K 0x00000004 617#define SQLITE_IOCAP_ATOMIC2K 0x00000008 618#define SQLITE_IOCAP_ATOMIC4K 0x00000010 619#define SQLITE_IOCAP_ATOMIC8K 0x00000020 620#define SQLITE_IOCAP_ATOMIC16K 0x00000040 621#define SQLITE_IOCAP_ATOMIC32K 0x00000080 622#define SQLITE_IOCAP_ATOMIC64K 0x00000100 623#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 624#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 625#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 626#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 627#define SQLITE_IOCAP_IMMUTABLE 0x00002000 628#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 629 630/* 631** CAPI3REF: File Locking Levels 632** 633** SQLite uses one of these integer values as the second 634** argument to calls it makes to the xLock() and xUnlock() methods 635** of an [sqlite3_io_methods] object. 636*/ 637#define SQLITE_LOCK_NONE 0 638#define SQLITE_LOCK_SHARED 1 639#define SQLITE_LOCK_RESERVED 2 640#define SQLITE_LOCK_PENDING 3 641#define SQLITE_LOCK_EXCLUSIVE 4 642 643/* 644** CAPI3REF: Synchronization Type Flags 645** 646** When SQLite invokes the xSync() method of an 647** [sqlite3_io_methods] object it uses a combination of 648** these integer values as the second argument. 649** 650** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 651** sync operation only needs to flush data to mass storage. Inode 652** information need not be flushed. If the lower four bits of the flag 653** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 654** If the lower four bits equal SQLITE_SYNC_FULL, that means 655** to use Mac OS X style fullsync instead of fsync(). 656** 657** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 658** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 659** settings. The [synchronous pragma] determines when calls to the 660** xSync VFS method occur and applies uniformly across all platforms. 661** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 662** energetic or rigorous or forceful the sync operations are and 663** only make a difference on Mac OSX for the default SQLite code. 664** (Third-party VFS implementations might also make the distinction 665** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 666** operating systems natively supported by SQLite, only Mac OSX 667** cares about the difference.) 668*/ 669#define SQLITE_SYNC_NORMAL 0x00002 670#define SQLITE_SYNC_FULL 0x00003 671#define SQLITE_SYNC_DATAONLY 0x00010 672 673/* 674** CAPI3REF: OS Interface Open File Handle 675** 676** An [sqlite3_file] object represents an open file in the 677** [sqlite3_vfs | OS interface layer]. Individual OS interface 678** implementations will 679** want to subclass this object by appending additional fields 680** for their own use. The pMethods entry is a pointer to an 681** [sqlite3_io_methods] object that defines methods for performing 682** I/O operations on the open file. 683*/ 684typedef struct sqlite3_file sqlite3_file; 685struct sqlite3_file { 686 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 687}; 688 689/* 690** CAPI3REF: OS Interface File Virtual Methods Object 691** 692** Every file opened by the [sqlite3_vfs.xOpen] method populates an 693** [sqlite3_file] object (or, more commonly, a subclass of the 694** [sqlite3_file] object) with a pointer to an instance of this object. 695** This object defines the methods used to perform various operations 696** against the open file represented by the [sqlite3_file] object. 697** 698** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 699** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 700** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 701** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 702** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 703** to NULL. 704** 705** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 706** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 707** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 708** flag may be ORed in to indicate that only the data of the file 709** and not its inode needs to be synced. 710** 711** The integer values to xLock() and xUnlock() are one of 712** <ul> 713** <li> [SQLITE_LOCK_NONE], 714** <li> [SQLITE_LOCK_SHARED], 715** <li> [SQLITE_LOCK_RESERVED], 716** <li> [SQLITE_LOCK_PENDING], or 717** <li> [SQLITE_LOCK_EXCLUSIVE]. 718** </ul> 719** xLock() increases the lock. xUnlock() decreases the lock. 720** The xCheckReservedLock() method checks whether any database connection, 721** either in this process or in some other process, is holding a RESERVED, 722** PENDING, or EXCLUSIVE lock on the file. It returns true 723** if such a lock exists and false otherwise. 724** 725** The xFileControl() method is a generic interface that allows custom 726** VFS implementations to directly control an open file using the 727** [sqlite3_file_control()] interface. The second "op" argument is an 728** integer opcode. The third argument is a generic pointer intended to 729** point to a structure that may contain arguments or space in which to 730** write return values. Potential uses for xFileControl() might be 731** functions to enable blocking locks with timeouts, to change the 732** locking strategy (for example to use dot-file locks), to inquire 733** about the status of a lock, or to break stale locks. The SQLite 734** core reserves all opcodes less than 100 for its own use. 735** A [file control opcodes | list of opcodes] less than 100 is available. 736** Applications that define a custom xFileControl method should use opcodes 737** greater than 100 to avoid conflicts. VFS implementations should 738** return [SQLITE_NOTFOUND] for file control opcodes that they do not 739** recognize. 740** 741** The xSectorSize() method returns the sector size of the 742** device that underlies the file. The sector size is the 743** minimum write that can be performed without disturbing 744** other bytes in the file. The xDeviceCharacteristics() 745** method returns a bit vector describing behaviors of the 746** underlying device: 747** 748** <ul> 749** <li> [SQLITE_IOCAP_ATOMIC] 750** <li> [SQLITE_IOCAP_ATOMIC512] 751** <li> [SQLITE_IOCAP_ATOMIC1K] 752** <li> [SQLITE_IOCAP_ATOMIC2K] 753** <li> [SQLITE_IOCAP_ATOMIC4K] 754** <li> [SQLITE_IOCAP_ATOMIC8K] 755** <li> [SQLITE_IOCAP_ATOMIC16K] 756** <li> [SQLITE_IOCAP_ATOMIC32K] 757** <li> [SQLITE_IOCAP_ATOMIC64K] 758** <li> [SQLITE_IOCAP_SAFE_APPEND] 759** <li> [SQLITE_IOCAP_SEQUENTIAL] 760** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 761** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 762** <li> [SQLITE_IOCAP_IMMUTABLE] 763** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 764** </ul> 765** 766** The SQLITE_IOCAP_ATOMIC property means that all writes of 767** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 768** mean that writes of blocks that are nnn bytes in size and 769** are aligned to an address which is an integer multiple of 770** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 771** that when data is appended to a file, the data is appended 772** first then the size of the file is extended, never the other 773** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 774** information is written to disk in the same order as calls 775** to xWrite(). 776** 777** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 778** in the unread portions of the buffer with zeros. A VFS that 779** fails to zero-fill short reads might seem to work. However, 780** failure to zero-fill short reads will eventually lead to 781** database corruption. 782*/ 783typedef struct sqlite3_io_methods sqlite3_io_methods; 784struct sqlite3_io_methods { 785 int iVersion; 786 int (*xClose)(sqlite3_file*); 787 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 788 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 789 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 790 int (*xSync)(sqlite3_file*, int flags); 791 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 792 int (*xLock)(sqlite3_file*, int); 793 int (*xUnlock)(sqlite3_file*, int); 794 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 795 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 796 int (*xSectorSize)(sqlite3_file*); 797 int (*xDeviceCharacteristics)(sqlite3_file*); 798 /* Methods above are valid for version 1 */ 799 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 800 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 801 void (*xShmBarrier)(sqlite3_file*); 802 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 803 /* Methods above are valid for version 2 */ 804 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 805 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 806 /* Methods above are valid for version 3 */ 807 /* Additional methods may be added in future releases */ 808}; 809 810/* 811** CAPI3REF: Standard File Control Opcodes 812** KEYWORDS: {file control opcodes} {file control opcode} 813** 814** These integer constants are opcodes for the xFileControl method 815** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 816** interface. 817** 818** <ul> 819** <li>[[SQLITE_FCNTL_LOCKSTATE]] 820** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 821** opcode causes the xFileControl method to write the current state of 822** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 823** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 824** into an integer that the pArg argument points to. This capability 825** is used during testing and is only available when the SQLITE_TEST 826** compile-time option is used. 827** 828** <li>[[SQLITE_FCNTL_SIZE_HINT]] 829** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 830** layer a hint of how large the database file will grow to be during the 831** current transaction. This hint is not guaranteed to be accurate but it 832** is often close. The underlying VFS might choose to preallocate database 833** file space based on this hint in order to help writes to the database 834** file run faster. 835** 836** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 837** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 838** implements [sqlite3_deserialize()] to set an upper bound on the size 839** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 840** If the integer pointed to is negative, then it is filled in with the 841** current limit. Otherwise the limit is set to the larger of the value 842** of the integer pointed to and the current database size. The integer 843** pointed to is set to the new limit. 844** 845** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 846** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 847** extends and truncates the database file in chunks of a size specified 848** by the user. The fourth argument to [sqlite3_file_control()] should 849** point to an integer (type int) containing the new chunk-size to use 850** for the nominated database. Allocating database file space in large 851** chunks (say 1MB at a time), may reduce file-system fragmentation and 852** improve performance on some systems. 853** 854** <li>[[SQLITE_FCNTL_FILE_POINTER]] 855** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 856** to the [sqlite3_file] object associated with a particular database 857** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 858** 859** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 860** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 861** to the [sqlite3_file] object associated with the journal file (either 862** the [rollback journal] or the [write-ahead log]) for a particular database 863** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 864** 865** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 866** No longer in use. 867** 868** <li>[[SQLITE_FCNTL_SYNC]] 869** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 870** sent to the VFS immediately before the xSync method is invoked on a 871** database file descriptor. Or, if the xSync method is not invoked 872** because the user has configured SQLite with 873** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 874** of the xSync method. In most cases, the pointer argument passed with 875** this file-control is NULL. However, if the database file is being synced 876** as part of a multi-database commit, the argument points to a nul-terminated 877** string containing the transactions super-journal file name. VFSes that 878** do not need this signal should silently ignore this opcode. Applications 879** should not call [sqlite3_file_control()] with this opcode as doing so may 880** disrupt the operation of the specialized VFSes that do require it. 881** 882** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 883** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 884** and sent to the VFS after a transaction has been committed immediately 885** but before the database is unlocked. VFSes that do not need this signal 886** should silently ignore this opcode. Applications should not call 887** [sqlite3_file_control()] with this opcode as doing so may disrupt the 888** operation of the specialized VFSes that do require it. 889** 890** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 891** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 892** retry counts and intervals for certain disk I/O operations for the 893** windows [VFS] in order to provide robustness in the presence of 894** anti-virus programs. By default, the windows VFS will retry file read, 895** file write, and file delete operations up to 10 times, with a delay 896** of 25 milliseconds before the first retry and with the delay increasing 897** by an additional 25 milliseconds with each subsequent retry. This 898** opcode allows these two values (10 retries and 25 milliseconds of delay) 899** to be adjusted. The values are changed for all database connections 900** within the same process. The argument is a pointer to an array of two 901** integers where the first integer is the new retry count and the second 902** integer is the delay. If either integer is negative, then the setting 903** is not changed but instead the prior value of that setting is written 904** into the array entry, allowing the current retry settings to be 905** interrogated. The zDbName parameter is ignored. 906** 907** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 908** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 909** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 910** write ahead log ([WAL file]) and shared memory 911** files used for transaction control 912** are automatically deleted when the latest connection to the database 913** closes. Setting persistent WAL mode causes those files to persist after 914** close. Persisting the files is useful when other processes that do not 915** have write permission on the directory containing the database file want 916** to read the database file, as the WAL and shared memory files must exist 917** in order for the database to be readable. The fourth parameter to 918** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 919** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 920** WAL mode. If the integer is -1, then it is overwritten with the current 921** WAL persistence setting. 922** 923** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 924** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 925** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 926** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 927** xDeviceCharacteristics methods. The fourth parameter to 928** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 929** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 930** mode. If the integer is -1, then it is overwritten with the current 931** zero-damage mode setting. 932** 933** <li>[[SQLITE_FCNTL_OVERWRITE]] 934** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 935** a write transaction to indicate that, unless it is rolled back for some 936** reason, the entire database file will be overwritten by the current 937** transaction. This is used by VACUUM operations. 938** 939** <li>[[SQLITE_FCNTL_VFSNAME]] 940** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 941** all [VFSes] in the VFS stack. The names are of all VFS shims and the 942** final bottom-level VFS are written into memory obtained from 943** [sqlite3_malloc()] and the result is stored in the char* variable 944** that the fourth parameter of [sqlite3_file_control()] points to. 945** The caller is responsible for freeing the memory when done. As with 946** all file-control actions, there is no guarantee that this will actually 947** do anything. Callers should initialize the char* variable to a NULL 948** pointer in case this file-control is not implemented. This file-control 949** is intended for diagnostic use only. 950** 951** <li>[[SQLITE_FCNTL_VFS_POINTER]] 952** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 953** [VFSes] currently in use. ^(The argument X in 954** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 955** of type "[sqlite3_vfs] **". This opcodes will set *X 956** to a pointer to the top-level VFS.)^ 957** ^When there are multiple VFS shims in the stack, this opcode finds the 958** upper-most shim only. 959** 960** <li>[[SQLITE_FCNTL_PRAGMA]] 961** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 962** file control is sent to the open [sqlite3_file] object corresponding 963** to the database file to which the pragma statement refers. ^The argument 964** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 965** pointers to strings (char**) in which the second element of the array 966** is the name of the pragma and the third element is the argument to the 967** pragma or NULL if the pragma has no argument. ^The handler for an 968** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 969** of the char** argument point to a string obtained from [sqlite3_mprintf()] 970** or the equivalent and that string will become the result of the pragma or 971** the error message if the pragma fails. ^If the 972** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 973** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 974** file control returns [SQLITE_OK], then the parser assumes that the 975** VFS has handled the PRAGMA itself and the parser generates a no-op 976** prepared statement if result string is NULL, or that returns a copy 977** of the result string if the string is non-NULL. 978** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 979** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 980** that the VFS encountered an error while handling the [PRAGMA] and the 981** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 982** file control occurs at the beginning of pragma statement analysis and so 983** it is able to override built-in [PRAGMA] statements. 984** 985** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 986** ^The [SQLITE_FCNTL_BUSYHANDLER] 987** file-control may be invoked by SQLite on the database file handle 988** shortly after it is opened in order to provide a custom VFS with access 989** to the connection's busy-handler callback. The argument is of type (void**) 990** - an array of two (void *) values. The first (void *) actually points 991** to a function of type (int (*)(void *)). In order to invoke the connection's 992** busy-handler, this function should be invoked with the second (void *) in 993** the array as the only argument. If it returns non-zero, then the operation 994** should be retried. If it returns zero, the custom VFS should abandon the 995** current operation. 996** 997** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 998** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 999** to have SQLite generate a 1000** temporary filename using the same algorithm that is followed to generate 1001** temporary filenames for TEMP tables and other internal uses. The 1002** argument should be a char** which will be filled with the filename 1003** written into memory obtained from [sqlite3_malloc()]. The caller should 1004** invoke [sqlite3_free()] on the result to avoid a memory leak. 1005** 1006** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1007** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1008** maximum number of bytes that will be used for memory-mapped I/O. 1009** The argument is a pointer to a value of type sqlite3_int64 that 1010** is an advisory maximum number of bytes in the file to memory map. The 1011** pointer is overwritten with the old value. The limit is not changed if 1012** the value originally pointed to is negative, and so the current limit 1013** can be queried by passing in a pointer to a negative number. This 1014** file-control is used internally to implement [PRAGMA mmap_size]. 1015** 1016** <li>[[SQLITE_FCNTL_TRACE]] 1017** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1018** to the VFS about what the higher layers of the SQLite stack are doing. 1019** This file control is used by some VFS activity tracing [shims]. 1020** The argument is a zero-terminated string. Higher layers in the 1021** SQLite stack may generate instances of this file control if 1022** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1023** 1024** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1025** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1026** pointer to an integer and it writes a boolean into that integer depending 1027** on whether or not the file has been renamed, moved, or deleted since it 1028** was first opened. 1029** 1030** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1031** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1032** underlying native file handle associated with a file handle. This file 1033** control interprets its argument as a pointer to a native file handle and 1034** writes the resulting value there. 1035** 1036** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1037** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1038** opcode causes the xFileControl method to swap the file handle with the one 1039** pointed to by the pArg argument. This capability is used during testing 1040** and only needs to be supported when SQLITE_TEST is defined. 1041** 1042** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1043** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1044** be advantageous to block on the next WAL lock if the lock is not immediately 1045** available. The WAL subsystem issues this signal during rare 1046** circumstances in order to fix a problem with priority inversion. 1047** Applications should <em>not</em> use this file-control. 1048** 1049** <li>[[SQLITE_FCNTL_ZIPVFS]] 1050** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1051** VFS should return SQLITE_NOTFOUND for this opcode. 1052** 1053** <li>[[SQLITE_FCNTL_RBU]] 1054** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1055** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1056** this opcode. 1057** 1058** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1059** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1060** the file descriptor is placed in "batch write mode", which 1061** means all subsequent write operations will be deferred and done 1062** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1063** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1064** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1065** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1066** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1067** no VFS interface calls on the same [sqlite3_file] file descriptor 1068** except for calls to the xWrite method and the xFileControl method 1069** with [SQLITE_FCNTL_SIZE_HINT]. 1070** 1071** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1072** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1073** operations since the previous successful call to 1074** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1075** This file control returns [SQLITE_OK] if and only if the writes were 1076** all performed successfully and have been committed to persistent storage. 1077** ^Regardless of whether or not it is successful, this file control takes 1078** the file descriptor out of batch write mode so that all subsequent 1079** write operations are independent. 1080** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1081** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1082** 1083** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1084** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1085** operations since the previous successful call to 1086** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1087** ^This file control takes the file descriptor out of batch write mode 1088** so that all subsequent write operations are independent. 1089** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1090** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1091** 1092** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1093** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1094** to block for up to M milliseconds before failing when attempting to 1095** obtain a file lock using the xLock or xShmLock methods of the VFS. 1096** The parameter is a pointer to a 32-bit signed integer that contains 1097** the value that M is to be set to. Before returning, the 32-bit signed 1098** integer is overwritten with the previous value of M. 1099** 1100** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1101** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1102** a database file. The argument is a pointer to a 32-bit unsigned integer. 1103** The "data version" for the pager is written into the pointer. The 1104** "data version" changes whenever any change occurs to the corresponding 1105** database file, either through SQL statements on the same database 1106** connection or through transactions committed by separate database 1107** connections possibly in other processes. The [sqlite3_total_changes()] 1108** interface can be used to find if any database on the connection has changed, 1109** but that interface responds to changes on TEMP as well as MAIN and does 1110** not provide a mechanism to detect changes to MAIN only. Also, the 1111** [sqlite3_total_changes()] interface responds to internal changes only and 1112** omits changes made by other database connections. The 1113** [PRAGMA data_version] command provides a mechanism to detect changes to 1114** a single attached database that occur due to other database connections, 1115** but omits changes implemented by the database connection on which it is 1116** called. This file control is the only mechanism to detect changes that 1117** happen either internally or externally and that are associated with 1118** a particular attached database. 1119** 1120** <li>[[SQLITE_FCNTL_CKPT_START]] 1121** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1122** in wal mode before the client starts to copy pages from the wal 1123** file to the database file. 1124** 1125** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1126** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1127** in wal mode after the client has finished copying pages from the wal 1128** file to the database file, but before the *-shm file is updated to 1129** record the fact that the pages have been checkpointed. 1130** </ul> 1131*/ 1132#define SQLITE_FCNTL_LOCKSTATE 1 1133#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1134#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1135#define SQLITE_FCNTL_LAST_ERRNO 4 1136#define SQLITE_FCNTL_SIZE_HINT 5 1137#define SQLITE_FCNTL_CHUNK_SIZE 6 1138#define SQLITE_FCNTL_FILE_POINTER 7 1139#define SQLITE_FCNTL_SYNC_OMITTED 8 1140#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1141#define SQLITE_FCNTL_PERSIST_WAL 10 1142#define SQLITE_FCNTL_OVERWRITE 11 1143#define SQLITE_FCNTL_VFSNAME 12 1144#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1145#define SQLITE_FCNTL_PRAGMA 14 1146#define SQLITE_FCNTL_BUSYHANDLER 15 1147#define SQLITE_FCNTL_TEMPFILENAME 16 1148#define SQLITE_FCNTL_MMAP_SIZE 18 1149#define SQLITE_FCNTL_TRACE 19 1150#define SQLITE_FCNTL_HAS_MOVED 20 1151#define SQLITE_FCNTL_SYNC 21 1152#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1153#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1154#define SQLITE_FCNTL_WAL_BLOCK 24 1155#define SQLITE_FCNTL_ZIPVFS 25 1156#define SQLITE_FCNTL_RBU 26 1157#define SQLITE_FCNTL_VFS_POINTER 27 1158#define SQLITE_FCNTL_JOURNAL_POINTER 28 1159#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1160#define SQLITE_FCNTL_PDB 30 1161#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1162#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1163#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1164#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1165#define SQLITE_FCNTL_DATA_VERSION 35 1166#define SQLITE_FCNTL_SIZE_LIMIT 36 1167#define SQLITE_FCNTL_CKPT_DONE 37 1168#define SQLITE_FCNTL_RESERVE_BYTES 38 1169#define SQLITE_FCNTL_CKPT_START 39 1170 1171/* deprecated names */ 1172#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1173#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1174#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1175 1176 1177/* 1178** CAPI3REF: Mutex Handle 1179** 1180** The mutex module within SQLite defines [sqlite3_mutex] to be an 1181** abstract type for a mutex object. The SQLite core never looks 1182** at the internal representation of an [sqlite3_mutex]. It only 1183** deals with pointers to the [sqlite3_mutex] object. 1184** 1185** Mutexes are created using [sqlite3_mutex_alloc()]. 1186*/ 1187typedef struct sqlite3_mutex sqlite3_mutex; 1188 1189/* 1190** CAPI3REF: Loadable Extension Thunk 1191** 1192** A pointer to the opaque sqlite3_api_routines structure is passed as 1193** the third parameter to entry points of [loadable extensions]. This 1194** structure must be typedefed in order to work around compiler warnings 1195** on some platforms. 1196*/ 1197typedef struct sqlite3_api_routines sqlite3_api_routines; 1198 1199/* 1200** CAPI3REF: OS Interface Object 1201** 1202** An instance of the sqlite3_vfs object defines the interface between 1203** the SQLite core and the underlying operating system. The "vfs" 1204** in the name of the object stands for "virtual file system". See 1205** the [VFS | VFS documentation] for further information. 1206** 1207** The VFS interface is sometimes extended by adding new methods onto 1208** the end. Each time such an extension occurs, the iVersion field 1209** is incremented. The iVersion value started out as 1 in 1210** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1211** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1212** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1213** may be appended to the sqlite3_vfs object and the iVersion value 1214** may increase again in future versions of SQLite. 1215** Note that due to an oversight, the structure 1216** of the sqlite3_vfs object changed in the transition from 1217** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1218** and yet the iVersion field was not increased. 1219** 1220** The szOsFile field is the size of the subclassed [sqlite3_file] 1221** structure used by this VFS. mxPathname is the maximum length of 1222** a pathname in this VFS. 1223** 1224** Registered sqlite3_vfs objects are kept on a linked list formed by 1225** the pNext pointer. The [sqlite3_vfs_register()] 1226** and [sqlite3_vfs_unregister()] interfaces manage this list 1227** in a thread-safe way. The [sqlite3_vfs_find()] interface 1228** searches the list. Neither the application code nor the VFS 1229** implementation should use the pNext pointer. 1230** 1231** The pNext field is the only field in the sqlite3_vfs 1232** structure that SQLite will ever modify. SQLite will only access 1233** or modify this field while holding a particular static mutex. 1234** The application should never modify anything within the sqlite3_vfs 1235** object once the object has been registered. 1236** 1237** The zName field holds the name of the VFS module. The name must 1238** be unique across all VFS modules. 1239** 1240** [[sqlite3_vfs.xOpen]] 1241** ^SQLite guarantees that the zFilename parameter to xOpen 1242** is either a NULL pointer or string obtained 1243** from xFullPathname() with an optional suffix added. 1244** ^If a suffix is added to the zFilename parameter, it will 1245** consist of a single "-" character followed by no more than 1246** 11 alphanumeric and/or "-" characters. 1247** ^SQLite further guarantees that 1248** the string will be valid and unchanged until xClose() is 1249** called. Because of the previous sentence, 1250** the [sqlite3_file] can safely store a pointer to the 1251** filename if it needs to remember the filename for some reason. 1252** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1253** must invent its own temporary name for the file. ^Whenever the 1254** xFilename parameter is NULL it will also be the case that the 1255** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1256** 1257** The flags argument to xOpen() includes all bits set in 1258** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1259** or [sqlite3_open16()] is used, then flags includes at least 1260** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1261** If xOpen() opens a file read-only then it sets *pOutFlags to 1262** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1263** 1264** ^(SQLite will also add one of the following flags to the xOpen() 1265** call, depending on the object being opened: 1266** 1267** <ul> 1268** <li> [SQLITE_OPEN_MAIN_DB] 1269** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1270** <li> [SQLITE_OPEN_TEMP_DB] 1271** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1272** <li> [SQLITE_OPEN_TRANSIENT_DB] 1273** <li> [SQLITE_OPEN_SUBJOURNAL] 1274** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1275** <li> [SQLITE_OPEN_WAL] 1276** </ul>)^ 1277** 1278** The file I/O implementation can use the object type flags to 1279** change the way it deals with files. For example, an application 1280** that does not care about crash recovery or rollback might make 1281** the open of a journal file a no-op. Writes to this journal would 1282** also be no-ops, and any attempt to read the journal would return 1283** SQLITE_IOERR. Or the implementation might recognize that a database 1284** file will be doing page-aligned sector reads and writes in a random 1285** order and set up its I/O subsystem accordingly. 1286** 1287** SQLite might also add one of the following flags to the xOpen method: 1288** 1289** <ul> 1290** <li> [SQLITE_OPEN_DELETEONCLOSE] 1291** <li> [SQLITE_OPEN_EXCLUSIVE] 1292** </ul> 1293** 1294** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1295** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1296** will be set for TEMP databases and their journals, transient 1297** databases, and subjournals. 1298** 1299** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1300** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1301** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1302** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1303** SQLITE_OPEN_CREATE, is used to indicate that file should always 1304** be created, and that it is an error if it already exists. 1305** It is <i>not</i> used to indicate the file should be opened 1306** for exclusive access. 1307** 1308** ^At least szOsFile bytes of memory are allocated by SQLite 1309** to hold the [sqlite3_file] structure passed as the third 1310** argument to xOpen. The xOpen method does not have to 1311** allocate the structure; it should just fill it in. Note that 1312** the xOpen method must set the sqlite3_file.pMethods to either 1313** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1314** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1315** element will be valid after xOpen returns regardless of the success 1316** or failure of the xOpen call. 1317** 1318** [[sqlite3_vfs.xAccess]] 1319** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1320** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1321** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1322** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1323** flag is never actually used and is not implemented in the built-in 1324** VFSes of SQLite. The file is named by the second argument and can be a 1325** directory. The xAccess method returns [SQLITE_OK] on success or some 1326** non-zero error code if there is an I/O error or if the name of 1327** the file given in the second argument is illegal. If SQLITE_OK 1328** is returned, then non-zero or zero is written into *pResOut to indicate 1329** whether or not the file is accessible. 1330** 1331** ^SQLite will always allocate at least mxPathname+1 bytes for the 1332** output buffer xFullPathname. The exact size of the output buffer 1333** is also passed as a parameter to both methods. If the output buffer 1334** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1335** handled as a fatal error by SQLite, vfs implementations should endeavor 1336** to prevent this by setting mxPathname to a sufficiently large value. 1337** 1338** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1339** interfaces are not strictly a part of the filesystem, but they are 1340** included in the VFS structure for completeness. 1341** The xRandomness() function attempts to return nBytes bytes 1342** of good-quality randomness into zOut. The return value is 1343** the actual number of bytes of randomness obtained. 1344** The xSleep() method causes the calling thread to sleep for at 1345** least the number of microseconds given. ^The xCurrentTime() 1346** method returns a Julian Day Number for the current date and time as 1347** a floating point value. 1348** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1349** Day Number multiplied by 86400000 (the number of milliseconds in 1350** a 24-hour day). 1351** ^SQLite will use the xCurrentTimeInt64() method to get the current 1352** date and time if that method is available (if iVersion is 2 or 1353** greater and the function pointer is not NULL) and will fall back 1354** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1355** 1356** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1357** are not used by the SQLite core. These optional interfaces are provided 1358** by some VFSes to facilitate testing of the VFS code. By overriding 1359** system calls with functions under its control, a test program can 1360** simulate faults and error conditions that would otherwise be difficult 1361** or impossible to induce. The set of system calls that can be overridden 1362** varies from one VFS to another, and from one version of the same VFS to the 1363** next. Applications that use these interfaces must be prepared for any 1364** or all of these interfaces to be NULL or for their behavior to change 1365** from one release to the next. Applications must not attempt to access 1366** any of these methods if the iVersion of the VFS is less than 3. 1367*/ 1368typedef struct sqlite3_vfs sqlite3_vfs; 1369typedef void (*sqlite3_syscall_ptr)(void); 1370struct sqlite3_vfs { 1371 int iVersion; /* Structure version number (currently 3) */ 1372 int szOsFile; /* Size of subclassed sqlite3_file */ 1373 int mxPathname; /* Maximum file pathname length */ 1374 sqlite3_vfs *pNext; /* Next registered VFS */ 1375 const char *zName; /* Name of this virtual file system */ 1376 void *pAppData; /* Pointer to application-specific data */ 1377 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1378 int flags, int *pOutFlags); 1379 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1380 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1381 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1382 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1383 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1384 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1385 void (*xDlClose)(sqlite3_vfs*, void*); 1386 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1387 int (*xSleep)(sqlite3_vfs*, int microseconds); 1388 int (*xCurrentTime)(sqlite3_vfs*, double*); 1389 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1390 /* 1391 ** The methods above are in version 1 of the sqlite_vfs object 1392 ** definition. Those that follow are added in version 2 or later 1393 */ 1394 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1395 /* 1396 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1397 ** Those below are for version 3 and greater. 1398 */ 1399 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1400 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1401 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1402 /* 1403 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1404 ** New fields may be appended in future versions. The iVersion 1405 ** value will increment whenever this happens. 1406 */ 1407}; 1408 1409/* 1410** CAPI3REF: Flags for the xAccess VFS method 1411** 1412** These integer constants can be used as the third parameter to 1413** the xAccess method of an [sqlite3_vfs] object. They determine 1414** what kind of permissions the xAccess method is looking for. 1415** With SQLITE_ACCESS_EXISTS, the xAccess method 1416** simply checks whether the file exists. 1417** With SQLITE_ACCESS_READWRITE, the xAccess method 1418** checks whether the named directory is both readable and writable 1419** (in other words, if files can be added, removed, and renamed within 1420** the directory). 1421** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1422** [temp_store_directory pragma], though this could change in a future 1423** release of SQLite. 1424** With SQLITE_ACCESS_READ, the xAccess method 1425** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1426** currently unused, though it might be used in a future release of 1427** SQLite. 1428*/ 1429#define SQLITE_ACCESS_EXISTS 0 1430#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1431#define SQLITE_ACCESS_READ 2 /* Unused */ 1432 1433/* 1434** CAPI3REF: Flags for the xShmLock VFS method 1435** 1436** These integer constants define the various locking operations 1437** allowed by the xShmLock method of [sqlite3_io_methods]. The 1438** following are the only legal combinations of flags to the 1439** xShmLock method: 1440** 1441** <ul> 1442** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1443** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1444** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1445** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1446** </ul> 1447** 1448** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1449** was given on the corresponding lock. 1450** 1451** The xShmLock method can transition between unlocked and SHARED or 1452** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1453** and EXCLUSIVE. 1454*/ 1455#define SQLITE_SHM_UNLOCK 1 1456#define SQLITE_SHM_LOCK 2 1457#define SQLITE_SHM_SHARED 4 1458#define SQLITE_SHM_EXCLUSIVE 8 1459 1460/* 1461** CAPI3REF: Maximum xShmLock index 1462** 1463** The xShmLock method on [sqlite3_io_methods] may use values 1464** between 0 and this upper bound as its "offset" argument. 1465** The SQLite core will never attempt to acquire or release a 1466** lock outside of this range 1467*/ 1468#define SQLITE_SHM_NLOCK 8 1469 1470 1471/* 1472** CAPI3REF: Initialize The SQLite Library 1473** 1474** ^The sqlite3_initialize() routine initializes the 1475** SQLite library. ^The sqlite3_shutdown() routine 1476** deallocates any resources that were allocated by sqlite3_initialize(). 1477** These routines are designed to aid in process initialization and 1478** shutdown on embedded systems. Workstation applications using 1479** SQLite normally do not need to invoke either of these routines. 1480** 1481** A call to sqlite3_initialize() is an "effective" call if it is 1482** the first time sqlite3_initialize() is invoked during the lifetime of 1483** the process, or if it is the first time sqlite3_initialize() is invoked 1484** following a call to sqlite3_shutdown(). ^(Only an effective call 1485** of sqlite3_initialize() does any initialization. All other calls 1486** are harmless no-ops.)^ 1487** 1488** A call to sqlite3_shutdown() is an "effective" call if it is the first 1489** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1490** an effective call to sqlite3_shutdown() does any deinitialization. 1491** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1492** 1493** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1494** is not. The sqlite3_shutdown() interface must only be called from a 1495** single thread. All open [database connections] must be closed and all 1496** other SQLite resources must be deallocated prior to invoking 1497** sqlite3_shutdown(). 1498** 1499** Among other things, ^sqlite3_initialize() will invoke 1500** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1501** will invoke sqlite3_os_end(). 1502** 1503** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1504** ^If for some reason, sqlite3_initialize() is unable to initialize 1505** the library (perhaps it is unable to allocate a needed resource such 1506** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1507** 1508** ^The sqlite3_initialize() routine is called internally by many other 1509** SQLite interfaces so that an application usually does not need to 1510** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1511** calls sqlite3_initialize() so the SQLite library will be automatically 1512** initialized when [sqlite3_open()] is called if it has not be initialized 1513** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1514** compile-time option, then the automatic calls to sqlite3_initialize() 1515** are omitted and the application must call sqlite3_initialize() directly 1516** prior to using any other SQLite interface. For maximum portability, 1517** it is recommended that applications always invoke sqlite3_initialize() 1518** directly prior to using any other SQLite interface. Future releases 1519** of SQLite may require this. In other words, the behavior exhibited 1520** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1521** default behavior in some future release of SQLite. 1522** 1523** The sqlite3_os_init() routine does operating-system specific 1524** initialization of the SQLite library. The sqlite3_os_end() 1525** routine undoes the effect of sqlite3_os_init(). Typical tasks 1526** performed by these routines include allocation or deallocation 1527** of static resources, initialization of global variables, 1528** setting up a default [sqlite3_vfs] module, or setting up 1529** a default configuration using [sqlite3_config()]. 1530** 1531** The application should never invoke either sqlite3_os_init() 1532** or sqlite3_os_end() directly. The application should only invoke 1533** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1534** interface is called automatically by sqlite3_initialize() and 1535** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1536** implementations for sqlite3_os_init() and sqlite3_os_end() 1537** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1538** When [custom builds | built for other platforms] 1539** (using the [SQLITE_OS_OTHER=1] compile-time 1540** option) the application must supply a suitable implementation for 1541** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1542** implementation of sqlite3_os_init() or sqlite3_os_end() 1543** must return [SQLITE_OK] on success and some other [error code] upon 1544** failure. 1545*/ 1546SQLITE_API int sqlite3_initialize(void); 1547SQLITE_API int sqlite3_shutdown(void); 1548SQLITE_API int sqlite3_os_init(void); 1549SQLITE_API int sqlite3_os_end(void); 1550 1551/* 1552** CAPI3REF: Configuring The SQLite Library 1553** 1554** The sqlite3_config() interface is used to make global configuration 1555** changes to SQLite in order to tune SQLite to the specific needs of 1556** the application. The default configuration is recommended for most 1557** applications and so this routine is usually not necessary. It is 1558** provided to support rare applications with unusual needs. 1559** 1560** <b>The sqlite3_config() interface is not threadsafe. The application 1561** must ensure that no other SQLite interfaces are invoked by other 1562** threads while sqlite3_config() is running.</b> 1563** 1564** The sqlite3_config() interface 1565** may only be invoked prior to library initialization using 1566** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1567** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1568** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1569** Note, however, that ^sqlite3_config() can be called as part of the 1570** implementation of an application-defined [sqlite3_os_init()]. 1571** 1572** The first argument to sqlite3_config() is an integer 1573** [configuration option] that determines 1574** what property of SQLite is to be configured. Subsequent arguments 1575** vary depending on the [configuration option] 1576** in the first argument. 1577** 1578** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1579** ^If the option is unknown or SQLite is unable to set the option 1580** then this routine returns a non-zero [error code]. 1581*/ 1582SQLITE_API int sqlite3_config(int, ...); 1583 1584/* 1585** CAPI3REF: Configure database connections 1586** METHOD: sqlite3 1587** 1588** The sqlite3_db_config() interface is used to make configuration 1589** changes to a [database connection]. The interface is similar to 1590** [sqlite3_config()] except that the changes apply to a single 1591** [database connection] (specified in the first argument). 1592** 1593** The second argument to sqlite3_db_config(D,V,...) is the 1594** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1595** that indicates what aspect of the [database connection] is being configured. 1596** Subsequent arguments vary depending on the configuration verb. 1597** 1598** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1599** the call is considered successful. 1600*/ 1601SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1602 1603/* 1604** CAPI3REF: Memory Allocation Routines 1605** 1606** An instance of this object defines the interface between SQLite 1607** and low-level memory allocation routines. 1608** 1609** This object is used in only one place in the SQLite interface. 1610** A pointer to an instance of this object is the argument to 1611** [sqlite3_config()] when the configuration option is 1612** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1613** By creating an instance of this object 1614** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1615** during configuration, an application can specify an alternative 1616** memory allocation subsystem for SQLite to use for all of its 1617** dynamic memory needs. 1618** 1619** Note that SQLite comes with several [built-in memory allocators] 1620** that are perfectly adequate for the overwhelming majority of applications 1621** and that this object is only useful to a tiny minority of applications 1622** with specialized memory allocation requirements. This object is 1623** also used during testing of SQLite in order to specify an alternative 1624** memory allocator that simulates memory out-of-memory conditions in 1625** order to verify that SQLite recovers gracefully from such 1626** conditions. 1627** 1628** The xMalloc, xRealloc, and xFree methods must work like the 1629** malloc(), realloc() and free() functions from the standard C library. 1630** ^SQLite guarantees that the second argument to 1631** xRealloc is always a value returned by a prior call to xRoundup. 1632** 1633** xSize should return the allocated size of a memory allocation 1634** previously obtained from xMalloc or xRealloc. The allocated size 1635** is always at least as big as the requested size but may be larger. 1636** 1637** The xRoundup method returns what would be the allocated size of 1638** a memory allocation given a particular requested size. Most memory 1639** allocators round up memory allocations at least to the next multiple 1640** of 8. Some allocators round up to a larger multiple or to a power of 2. 1641** Every memory allocation request coming in through [sqlite3_malloc()] 1642** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1643** that causes the corresponding memory allocation to fail. 1644** 1645** The xInit method initializes the memory allocator. For example, 1646** it might allocate any required mutexes or initialize internal data 1647** structures. The xShutdown method is invoked (indirectly) by 1648** [sqlite3_shutdown()] and should deallocate any resources acquired 1649** by xInit. The pAppData pointer is used as the only parameter to 1650** xInit and xShutdown. 1651** 1652** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1653** the xInit method, so the xInit method need not be threadsafe. The 1654** xShutdown method is only called from [sqlite3_shutdown()] so it does 1655** not need to be threadsafe either. For all other methods, SQLite 1656** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1657** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1658** it is by default) and so the methods are automatically serialized. 1659** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1660** methods must be threadsafe or else make their own arrangements for 1661** serialization. 1662** 1663** SQLite will never invoke xInit() more than once without an intervening 1664** call to xShutdown(). 1665*/ 1666typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1667struct sqlite3_mem_methods { 1668 void *(*xMalloc)(int); /* Memory allocation function */ 1669 void (*xFree)(void*); /* Free a prior allocation */ 1670 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1671 int (*xSize)(void*); /* Return the size of an allocation */ 1672 int (*xRoundup)(int); /* Round up request size to allocation size */ 1673 int (*xInit)(void*); /* Initialize the memory allocator */ 1674 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1675 void *pAppData; /* Argument to xInit() and xShutdown() */ 1676}; 1677 1678/* 1679** CAPI3REF: Configuration Options 1680** KEYWORDS: {configuration option} 1681** 1682** These constants are the available integer configuration options that 1683** can be passed as the first argument to the [sqlite3_config()] interface. 1684** 1685** New configuration options may be added in future releases of SQLite. 1686** Existing configuration options might be discontinued. Applications 1687** should check the return code from [sqlite3_config()] to make sure that 1688** the call worked. The [sqlite3_config()] interface will return a 1689** non-zero [error code] if a discontinued or unsupported configuration option 1690** is invoked. 1691** 1692** <dl> 1693** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1694** <dd>There are no arguments to this option. ^This option sets the 1695** [threading mode] to Single-thread. In other words, it disables 1696** all mutexing and puts SQLite into a mode where it can only be used 1697** by a single thread. ^If SQLite is compiled with 1698** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1699** it is not possible to change the [threading mode] from its default 1700** value of Single-thread and so [sqlite3_config()] will return 1701** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1702** configuration option.</dd> 1703** 1704** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1705** <dd>There are no arguments to this option. ^This option sets the 1706** [threading mode] to Multi-thread. In other words, it disables 1707** mutexing on [database connection] and [prepared statement] objects. 1708** The application is responsible for serializing access to 1709** [database connections] and [prepared statements]. But other mutexes 1710** are enabled so that SQLite will be safe to use in a multi-threaded 1711** environment as long as no two threads attempt to use the same 1712** [database connection] at the same time. ^If SQLite is compiled with 1713** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1714** it is not possible to set the Multi-thread [threading mode] and 1715** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1716** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1717** 1718** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1719** <dd>There are no arguments to this option. ^This option sets the 1720** [threading mode] to Serialized. In other words, this option enables 1721** all mutexes including the recursive 1722** mutexes on [database connection] and [prepared statement] objects. 1723** In this mode (which is the default when SQLite is compiled with 1724** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1725** to [database connections] and [prepared statements] so that the 1726** application is free to use the same [database connection] or the 1727** same [prepared statement] in different threads at the same time. 1728** ^If SQLite is compiled with 1729** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1730** it is not possible to set the Serialized [threading mode] and 1731** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1732** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1733** 1734** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1735** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1736** a pointer to an instance of the [sqlite3_mem_methods] structure. 1737** The argument specifies 1738** alternative low-level memory allocation routines to be used in place of 1739** the memory allocation routines built into SQLite.)^ ^SQLite makes 1740** its own private copy of the content of the [sqlite3_mem_methods] structure 1741** before the [sqlite3_config()] call returns.</dd> 1742** 1743** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1744** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1745** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1746** The [sqlite3_mem_methods] 1747** structure is filled with the currently defined memory allocation routines.)^ 1748** This option can be used to overload the default memory allocation 1749** routines with a wrapper that simulations memory allocation failure or 1750** tracks memory usage, for example. </dd> 1751** 1752** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1753** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1754** type int, interpreted as a boolean, which if true provides a hint to 1755** SQLite that it should avoid large memory allocations if possible. 1756** SQLite will run faster if it is free to make large memory allocations, 1757** but some application might prefer to run slower in exchange for 1758** guarantees about memory fragmentation that are possible if large 1759** allocations are avoided. This hint is normally off. 1760** </dd> 1761** 1762** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1763** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1764** interpreted as a boolean, which enables or disables the collection of 1765** memory allocation statistics. ^(When memory allocation statistics are 1766** disabled, the following SQLite interfaces become non-operational: 1767** <ul> 1768** <li> [sqlite3_hard_heap_limit64()] 1769** <li> [sqlite3_memory_used()] 1770** <li> [sqlite3_memory_highwater()] 1771** <li> [sqlite3_soft_heap_limit64()] 1772** <li> [sqlite3_status64()] 1773** </ul>)^ 1774** ^Memory allocation statistics are enabled by default unless SQLite is 1775** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1776** allocation statistics are disabled by default. 1777** </dd> 1778** 1779** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1780** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1781** </dd> 1782** 1783** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1784** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1785** that SQLite can use for the database page cache with the default page 1786** cache implementation. 1787** This configuration option is a no-op if an application-defined page 1788** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1789** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1790** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1791** and the number of cache lines (N). 1792** The sz argument should be the size of the largest database page 1793** (a power of two between 512 and 65536) plus some extra bytes for each 1794** page header. ^The number of extra bytes needed by the page header 1795** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1796** ^It is harmless, apart from the wasted memory, 1797** for the sz parameter to be larger than necessary. The pMem 1798** argument must be either a NULL pointer or a pointer to an 8-byte 1799** aligned block of memory of at least sz*N bytes, otherwise 1800** subsequent behavior is undefined. 1801** ^When pMem is not NULL, SQLite will strive to use the memory provided 1802** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1803** a page cache line is larger than sz bytes or if all of the pMem buffer 1804** is exhausted. 1805** ^If pMem is NULL and N is non-zero, then each database connection 1806** does an initial bulk allocation for page cache memory 1807** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1808** of -1024*N bytes if N is negative, . ^If additional 1809** page cache memory is needed beyond what is provided by the initial 1810** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1811** additional cache line. </dd> 1812** 1813** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1814** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1815** that SQLite will use for all of its dynamic memory allocation needs 1816** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1817** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1818** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1819** [SQLITE_ERROR] if invoked otherwise. 1820** ^There are three arguments to SQLITE_CONFIG_HEAP: 1821** An 8-byte aligned pointer to the memory, 1822** the number of bytes in the memory buffer, and the minimum allocation size. 1823** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1824** to using its default memory allocator (the system malloc() implementation), 1825** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1826** memory pointer is not NULL then the alternative memory 1827** allocator is engaged to handle all of SQLites memory allocation needs. 1828** The first pointer (the memory pointer) must be aligned to an 8-byte 1829** boundary or subsequent behavior of SQLite will be undefined. 1830** The minimum allocation size is capped at 2**12. Reasonable values 1831** for the minimum allocation size are 2**5 through 2**8.</dd> 1832** 1833** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1834** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1835** pointer to an instance of the [sqlite3_mutex_methods] structure. 1836** The argument specifies alternative low-level mutex routines to be used 1837** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1838** the content of the [sqlite3_mutex_methods] structure before the call to 1839** [sqlite3_config()] returns. ^If SQLite is compiled with 1840** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1841** the entire mutexing subsystem is omitted from the build and hence calls to 1842** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1843** return [SQLITE_ERROR].</dd> 1844** 1845** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1846** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1847** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1848** [sqlite3_mutex_methods] 1849** structure is filled with the currently defined mutex routines.)^ 1850** This option can be used to overload the default mutex allocation 1851** routines with a wrapper used to track mutex usage for performance 1852** profiling or testing, for example. ^If SQLite is compiled with 1853** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1854** the entire mutexing subsystem is omitted from the build and hence calls to 1855** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1856** return [SQLITE_ERROR].</dd> 1857** 1858** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1859** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1860** the default size of lookaside memory on each [database connection]. 1861** The first argument is the 1862** size of each lookaside buffer slot and the second is the number of 1863** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1864** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1865** option to [sqlite3_db_config()] can be used to change the lookaside 1866** configuration on individual connections.)^ </dd> 1867** 1868** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1869** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1870** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1871** the interface to a custom page cache implementation.)^ 1872** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1873** 1874** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1875** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1876** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1877** the current page cache implementation into that object.)^ </dd> 1878** 1879** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1880** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1881** global [error log]. 1882** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1883** function with a call signature of void(*)(void*,int,const char*), 1884** and a pointer to void. ^If the function pointer is not NULL, it is 1885** invoked by [sqlite3_log()] to process each logging event. ^If the 1886** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1887** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1888** passed through as the first parameter to the application-defined logger 1889** function whenever that function is invoked. ^The second parameter to 1890** the logger function is a copy of the first parameter to the corresponding 1891** [sqlite3_log()] call and is intended to be a [result code] or an 1892** [extended result code]. ^The third parameter passed to the logger is 1893** log message after formatting via [sqlite3_snprintf()]. 1894** The SQLite logging interface is not reentrant; the logger function 1895** supplied by the application must not invoke any SQLite interface. 1896** In a multi-threaded application, the application-defined logger 1897** function must be threadsafe. </dd> 1898** 1899** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1900** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1901** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1902** then URI handling is globally disabled.)^ ^If URI handling is globally 1903** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1904** [sqlite3_open16()] or 1905** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1906** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1907** connection is opened. ^If it is globally disabled, filenames are 1908** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1909** database connection is opened. ^(By default, URI handling is globally 1910** disabled. The default value may be changed by compiling with the 1911** [SQLITE_USE_URI] symbol defined.)^ 1912** 1913** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1914** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1915** argument which is interpreted as a boolean in order to enable or disable 1916** the use of covering indices for full table scans in the query optimizer. 1917** ^The default setting is determined 1918** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1919** if that compile-time option is omitted. 1920** The ability to disable the use of covering indices for full table scans 1921** is because some incorrectly coded legacy applications might malfunction 1922** when the optimization is enabled. Providing the ability to 1923** disable the optimization allows the older, buggy application code to work 1924** without change even with newer versions of SQLite. 1925** 1926** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1927** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1928** <dd> These options are obsolete and should not be used by new code. 1929** They are retained for backwards compatibility but are now no-ops. 1930** </dd> 1931** 1932** [[SQLITE_CONFIG_SQLLOG]] 1933** <dt>SQLITE_CONFIG_SQLLOG 1934** <dd>This option is only available if sqlite is compiled with the 1935** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1936** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1937** The second should be of type (void*). The callback is invoked by the library 1938** in three separate circumstances, identified by the value passed as the 1939** fourth parameter. If the fourth parameter is 0, then the database connection 1940** passed as the second argument has just been opened. The third argument 1941** points to a buffer containing the name of the main database file. If the 1942** fourth parameter is 1, then the SQL statement that the third parameter 1943** points to has just been executed. Or, if the fourth parameter is 2, then 1944** the connection being passed as the second parameter is being closed. The 1945** third parameter is passed NULL In this case. An example of using this 1946** configuration option can be seen in the "test_sqllog.c" source file in 1947** the canonical SQLite source tree.</dd> 1948** 1949** [[SQLITE_CONFIG_MMAP_SIZE]] 1950** <dt>SQLITE_CONFIG_MMAP_SIZE 1951** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1952** that are the default mmap size limit (the default setting for 1953** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1954** ^The default setting can be overridden by each database connection using 1955** either the [PRAGMA mmap_size] command, or by using the 1956** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1957** will be silently truncated if necessary so that it does not exceed the 1958** compile-time maximum mmap size set by the 1959** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1960** ^If either argument to this option is negative, then that argument is 1961** changed to its compile-time default. 1962** 1963** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1964** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1965** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1966** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1967** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1968** that specifies the maximum size of the created heap. 1969** 1970** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1971** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1972** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1973** is a pointer to an integer and writes into that integer the number of extra 1974** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1975** The amount of extra space required can change depending on the compiler, 1976** target platform, and SQLite version. 1977** 1978** [[SQLITE_CONFIG_PMASZ]] 1979** <dt>SQLITE_CONFIG_PMASZ 1980** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1981** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1982** sorter to that integer. The default minimum PMA Size is set by the 1983** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1984** to help with sort operations when multithreaded sorting 1985** is enabled (using the [PRAGMA threads] command) and the amount of content 1986** to be sorted exceeds the page size times the minimum of the 1987** [PRAGMA cache_size] setting and this value. 1988** 1989** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1990** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1991** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1992** becomes the [statement journal] spill-to-disk threshold. 1993** [Statement journals] are held in memory until their size (in bytes) 1994** exceeds this threshold, at which point they are written to disk. 1995** Or if the threshold is -1, statement journals are always held 1996** exclusively in memory. 1997** Since many statement journals never become large, setting the spill 1998** threshold to a value such as 64KiB can greatly reduce the amount of 1999** I/O required to support statement rollback. 2000** The default value for this setting is controlled by the 2001** [SQLITE_STMTJRNL_SPILL] compile-time option. 2002** 2003** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2004** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2005** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2006** of type (int) - the new value of the sorter-reference size threshold. 2007** Usually, when SQLite uses an external sort to order records according 2008** to an ORDER BY clause, all fields required by the caller are present in the 2009** sorted records. However, if SQLite determines based on the declared type 2010** of a table column that its values are likely to be very large - larger 2011** than the configured sorter-reference size threshold - then a reference 2012** is stored in each sorted record and the required column values loaded 2013** from the database as records are returned in sorted order. The default 2014** value for this option is to never use this optimization. Specifying a 2015** negative value for this option restores the default behaviour. 2016** This option is only available if SQLite is compiled with the 2017** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2018** 2019** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2020** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2021** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2022** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2023** database created using [sqlite3_deserialize()]. This default maximum 2024** size can be adjusted up or down for individual databases using the 2025** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2026** configuration setting is never used, then the default maximum is determined 2027** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2028** compile-time option is not set, then the default maximum is 1073741824. 2029** </dl> 2030*/ 2031#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2032#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2033#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2034#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2035#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2036#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2037#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2038#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2039#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2040#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2041#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2042/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2043#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2044#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2045#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2046#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2047#define SQLITE_CONFIG_URI 17 /* int */ 2048#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2049#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2050#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2051#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2052#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2053#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2054#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2055#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2056#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2057#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2058#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2059#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2060 2061/* 2062** CAPI3REF: Database Connection Configuration Options 2063** 2064** These constants are the available integer configuration options that 2065** can be passed as the second argument to the [sqlite3_db_config()] interface. 2066** 2067** New configuration options may be added in future releases of SQLite. 2068** Existing configuration options might be discontinued. Applications 2069** should check the return code from [sqlite3_db_config()] to make sure that 2070** the call worked. ^The [sqlite3_db_config()] interface will return a 2071** non-zero [error code] if a discontinued or unsupported configuration option 2072** is invoked. 2073** 2074** <dl> 2075** [[SQLITE_DBCONFIG_LOOKASIDE]] 2076** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2077** <dd> ^This option takes three additional arguments that determine the 2078** [lookaside memory allocator] configuration for the [database connection]. 2079** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2080** pointer to a memory buffer to use for lookaside memory. 2081** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2082** may be NULL in which case SQLite will allocate the 2083** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2084** size of each lookaside buffer slot. ^The third argument is the number of 2085** slots. The size of the buffer in the first argument must be greater than 2086** or equal to the product of the second and third arguments. The buffer 2087** must be aligned to an 8-byte boundary. ^If the second argument to 2088** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2089** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2090** configuration for a database connection can only be changed when that 2091** connection is not currently using lookaside memory, or in other words 2092** when the "current value" returned by 2093** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2094** Any attempt to change the lookaside memory configuration when lookaside 2095** memory is in use leaves the configuration unchanged and returns 2096** [SQLITE_BUSY].)^</dd> 2097** 2098** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2099** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2100** <dd> ^This option is used to enable or disable the enforcement of 2101** [foreign key constraints]. There should be two additional arguments. 2102** The first argument is an integer which is 0 to disable FK enforcement, 2103** positive to enable FK enforcement or negative to leave FK enforcement 2104** unchanged. The second parameter is a pointer to an integer into which 2105** is written 0 or 1 to indicate whether FK enforcement is off or on 2106** following this call. The second parameter may be a NULL pointer, in 2107** which case the FK enforcement setting is not reported back. </dd> 2108** 2109** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2110** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2111** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2112** There should be two additional arguments. 2113** The first argument is an integer which is 0 to disable triggers, 2114** positive to enable triggers or negative to leave the setting unchanged. 2115** The second parameter is a pointer to an integer into which 2116** is written 0 or 1 to indicate whether triggers are disabled or enabled 2117** following this call. The second parameter may be a NULL pointer, in 2118** which case the trigger setting is not reported back. 2119** 2120** <p>Originally this option disabled all triggers. ^(However, since 2121** SQLite version 3.35.0, TEMP triggers are still allowed even if 2122** this option is off. So, in other words, this option now only disables 2123** triggers in the main database schema or in the schemas of ATTACH-ed 2124** databases.)^ </dd> 2125** 2126** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2127** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2128** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2129** There should be two additional arguments. 2130** The first argument is an integer which is 0 to disable views, 2131** positive to enable views or negative to leave the setting unchanged. 2132** The second parameter is a pointer to an integer into which 2133** is written 0 or 1 to indicate whether views are disabled or enabled 2134** following this call. The second parameter may be a NULL pointer, in 2135** which case the view setting is not reported back. 2136** 2137** <p>Originally this option disabled all views. ^(However, since 2138** SQLite version 3.35.0, TEMP views are still allowed even if 2139** this option is off. So, in other words, this option now only disables 2140** views in the main database schema or in the schemas of ATTACH-ed 2141** databases.)^ </dd> 2142** 2143** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2144** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2145** <dd> ^This option is used to enable or disable the 2146** [fts3_tokenizer()] function which is part of the 2147** [FTS3] full-text search engine extension. 2148** There should be two additional arguments. 2149** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2150** positive to enable fts3_tokenizer() or negative to leave the setting 2151** unchanged. 2152** The second parameter is a pointer to an integer into which 2153** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2154** following this call. The second parameter may be a NULL pointer, in 2155** which case the new setting is not reported back. </dd> 2156** 2157** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2158** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2159** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2160** interface independently of the [load_extension()] SQL function. 2161** The [sqlite3_enable_load_extension()] API enables or disables both the 2162** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2163** There should be two additional arguments. 2164** When the first argument to this interface is 1, then only the C-API is 2165** enabled and the SQL function remains disabled. If the first argument to 2166** this interface is 0, then both the C-API and the SQL function are disabled. 2167** If the first argument is -1, then no changes are made to state of either the 2168** C-API or the SQL function. 2169** The second parameter is a pointer to an integer into which 2170** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2171** is disabled or enabled following this call. The second parameter may 2172** be a NULL pointer, in which case the new setting is not reported back. 2173** </dd> 2174** 2175** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2176** <dd> ^This option is used to change the name of the "main" database 2177** schema. ^The sole argument is a pointer to a constant UTF8 string 2178** which will become the new schema name in place of "main". ^SQLite 2179** does not make a copy of the new main schema name string, so the application 2180** must ensure that the argument passed into this DBCONFIG option is unchanged 2181** until after the database connection closes. 2182** </dd> 2183** 2184** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2185** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2186** <dd> Usually, when a database in wal mode is closed or detached from a 2187** database handle, SQLite checks if this will mean that there are now no 2188** connections at all to the database. If so, it performs a checkpoint 2189** operation before closing the connection. This option may be used to 2190** override this behaviour. The first parameter passed to this operation 2191** is an integer - positive to disable checkpoints-on-close, or zero (the 2192** default) to enable them, and negative to leave the setting unchanged. 2193** The second parameter is a pointer to an integer 2194** into which is written 0 or 1 to indicate whether checkpoints-on-close 2195** have been disabled - 0 if they are not disabled, 1 if they are. 2196** </dd> 2197** 2198** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2199** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2200** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2201** a single SQL query statement will always use the same algorithm regardless 2202** of values of [bound parameters].)^ The QPSG disables some query optimizations 2203** that look at the values of bound parameters, which can make some queries 2204** slower. But the QPSG has the advantage of more predictable behavior. With 2205** the QPSG active, SQLite will always use the same query plan in the field as 2206** was used during testing in the lab. 2207** The first argument to this setting is an integer which is 0 to disable 2208** the QPSG, positive to enable QPSG, or negative to leave the setting 2209** unchanged. The second parameter is a pointer to an integer into which 2210** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2211** following this call. 2212** </dd> 2213** 2214** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2215** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2216** include output for any operations performed by trigger programs. This 2217** option is used to set or clear (the default) a flag that governs this 2218** behavior. The first parameter passed to this operation is an integer - 2219** positive to enable output for trigger programs, or zero to disable it, 2220** or negative to leave the setting unchanged. 2221** The second parameter is a pointer to an integer into which is written 2222** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2223** it is not disabled, 1 if it is. 2224** </dd> 2225** 2226** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2227** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2228** [VACUUM] in order to reset a database back to an empty database 2229** with no schema and no content. The following process works even for 2230** a badly corrupted database file: 2231** <ol> 2232** <li> If the database connection is newly opened, make sure it has read the 2233** database schema by preparing then discarding some query against the 2234** database, or calling sqlite3_table_column_metadata(), ignoring any 2235** errors. This step is only necessary if the application desires to keep 2236** the database in WAL mode after the reset if it was in WAL mode before 2237** the reset. 2238** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2239** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2240** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2241** </ol> 2242** Because resetting a database is destructive and irreversible, the 2243** process requires the use of this obscure API and multiple steps to help 2244** ensure that it does not happen by accident. 2245** 2246** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2247** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2248** "defensive" flag for a database connection. When the defensive 2249** flag is enabled, language features that allow ordinary SQL to 2250** deliberately corrupt the database file are disabled. The disabled 2251** features include but are not limited to the following: 2252** <ul> 2253** <li> The [PRAGMA writable_schema=ON] statement. 2254** <li> The [PRAGMA journal_mode=OFF] statement. 2255** <li> Writes to the [sqlite_dbpage] virtual table. 2256** <li> Direct writes to [shadow tables]. 2257** </ul> 2258** </dd> 2259** 2260** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2261** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2262** "writable_schema" flag. This has the same effect and is logically equivalent 2263** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2264** The first argument to this setting is an integer which is 0 to disable 2265** the writable_schema, positive to enable writable_schema, or negative to 2266** leave the setting unchanged. The second parameter is a pointer to an 2267** integer into which is written 0 or 1 to indicate whether the writable_schema 2268** is enabled or disabled following this call. 2269** </dd> 2270** 2271** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2272** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2273** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2274** the legacy behavior of the [ALTER TABLE RENAME] command such it 2275** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2276** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2277** additional information. This feature can also be turned on and off 2278** using the [PRAGMA legacy_alter_table] statement. 2279** </dd> 2280** 2281** [[SQLITE_DBCONFIG_DQS_DML]] 2282** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2283** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2284** the legacy [double-quoted string literal] misfeature for DML statements 2285** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2286** default value of this setting is determined by the [-DSQLITE_DQS] 2287** compile-time option. 2288** </dd> 2289** 2290** [[SQLITE_DBCONFIG_DQS_DDL]] 2291** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2292** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2293** the legacy [double-quoted string literal] misfeature for DDL statements, 2294** such as CREATE TABLE and CREATE INDEX. The 2295** default value of this setting is determined by the [-DSQLITE_DQS] 2296** compile-time option. 2297** </dd> 2298** 2299** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2300** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2301** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2302** assume that database schemas are untainted by malicious content. 2303** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2304** takes additional defensive steps to protect the application from harm 2305** including: 2306** <ul> 2307** <li> Prohibit the use of SQL functions inside triggers, views, 2308** CHECK constraints, DEFAULT clauses, expression indexes, 2309** partial indexes, or generated columns 2310** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2311** <li> Prohibit the use of virtual tables inside of triggers or views 2312** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2313** </ul> 2314** This setting defaults to "on" for legacy compatibility, however 2315** all applications are advised to turn it off if possible. This setting 2316** can also be controlled using the [PRAGMA trusted_schema] statement. 2317** </dd> 2318** 2319** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2320** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2321** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2322** the legacy file format flag. When activated, this flag causes all newly 2323** created database file to have a schema format version number (the 4-byte 2324** integer found at offset 44 into the database header) of 1. This in turn 2325** means that the resulting database file will be readable and writable by 2326** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2327** newly created databases are generally not understandable by SQLite versions 2328** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2329** is now scarcely any need to generated database files that are compatible 2330** all the way back to version 3.0.0, and so this setting is of little 2331** practical use, but is provided so that SQLite can continue to claim the 2332** ability to generate new database files that are compatible with version 2333** 3.0.0. 2334** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2335** the [VACUUM] command will fail with an obscure error when attempting to 2336** process a table with generated columns and a descending index. This is 2337** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2338** either generated columns or decending indexes. 2339** </dd> 2340** </dl> 2341*/ 2342#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2343#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2344#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2345#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2346#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2347#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2348#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2349#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2350#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2351#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2352#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2353#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2354#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2355#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2356#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2357#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2358#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2359#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2360#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2361 2362/* 2363** CAPI3REF: Enable Or Disable Extended Result Codes 2364** METHOD: sqlite3 2365** 2366** ^The sqlite3_extended_result_codes() routine enables or disables the 2367** [extended result codes] feature of SQLite. ^The extended result 2368** codes are disabled by default for historical compatibility. 2369*/ 2370SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2371 2372/* 2373** CAPI3REF: Last Insert Rowid 2374** METHOD: sqlite3 2375** 2376** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2377** has a unique 64-bit signed 2378** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2379** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2380** names are not also used by explicitly declared columns. ^If 2381** the table has a column of type [INTEGER PRIMARY KEY] then that column 2382** is another alias for the rowid. 2383** 2384** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2385** the most recent successful [INSERT] into a rowid table or [virtual table] 2386** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2387** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2388** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2389** zero. 2390** 2391** As well as being set automatically as rows are inserted into database 2392** tables, the value returned by this function may be set explicitly by 2393** [sqlite3_set_last_insert_rowid()] 2394** 2395** Some virtual table implementations may INSERT rows into rowid tables as 2396** part of committing a transaction (e.g. to flush data accumulated in memory 2397** to disk). In this case subsequent calls to this function return the rowid 2398** associated with these internal INSERT operations, which leads to 2399** unintuitive results. Virtual table implementations that do write to rowid 2400** tables in this way can avoid this problem by restoring the original 2401** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2402** control to the user. 2403** 2404** ^(If an [INSERT] occurs within a trigger then this routine will 2405** return the [rowid] of the inserted row as long as the trigger is 2406** running. Once the trigger program ends, the value returned 2407** by this routine reverts to what it was before the trigger was fired.)^ 2408** 2409** ^An [INSERT] that fails due to a constraint violation is not a 2410** successful [INSERT] and does not change the value returned by this 2411** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2412** and INSERT OR ABORT make no changes to the return value of this 2413** routine when their insertion fails. ^(When INSERT OR REPLACE 2414** encounters a constraint violation, it does not fail. The 2415** INSERT continues to completion after deleting rows that caused 2416** the constraint problem so INSERT OR REPLACE will always change 2417** the return value of this interface.)^ 2418** 2419** ^For the purposes of this routine, an [INSERT] is considered to 2420** be successful even if it is subsequently rolled back. 2421** 2422** This function is accessible to SQL statements via the 2423** [last_insert_rowid() SQL function]. 2424** 2425** If a separate thread performs a new [INSERT] on the same 2426** database connection while the [sqlite3_last_insert_rowid()] 2427** function is running and thus changes the last insert [rowid], 2428** then the value returned by [sqlite3_last_insert_rowid()] is 2429** unpredictable and might not equal either the old or the new 2430** last insert [rowid]. 2431*/ 2432SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2433 2434/* 2435** CAPI3REF: Set the Last Insert Rowid value. 2436** METHOD: sqlite3 2437** 2438** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2439** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2440** without inserting a row into the database. 2441*/ 2442SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2443 2444/* 2445** CAPI3REF: Count The Number Of Rows Modified 2446** METHOD: sqlite3 2447** 2448** ^This function returns the number of rows modified, inserted or 2449** deleted by the most recently completed INSERT, UPDATE or DELETE 2450** statement on the database connection specified by the only parameter. 2451** ^Executing any other type of SQL statement does not modify the value 2452** returned by this function. 2453** 2454** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2455** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2456** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2457** 2458** Changes to a view that are intercepted by 2459** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2460** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2461** DELETE statement run on a view is always zero. Only changes made to real 2462** tables are counted. 2463** 2464** Things are more complicated if the sqlite3_changes() function is 2465** executed while a trigger program is running. This may happen if the 2466** program uses the [changes() SQL function], or if some other callback 2467** function invokes sqlite3_changes() directly. Essentially: 2468** 2469** <ul> 2470** <li> ^(Before entering a trigger program the value returned by 2471** sqlite3_changes() function is saved. After the trigger program 2472** has finished, the original value is restored.)^ 2473** 2474** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2475** statement sets the value returned by sqlite3_changes() 2476** upon completion as normal. Of course, this value will not include 2477** any changes performed by sub-triggers, as the sqlite3_changes() 2478** value will be saved and restored after each sub-trigger has run.)^ 2479** </ul> 2480** 2481** ^This means that if the changes() SQL function (or similar) is used 2482** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2483** returns the value as set when the calling statement began executing. 2484** ^If it is used by the second or subsequent such statement within a trigger 2485** program, the value returned reflects the number of rows modified by the 2486** previous INSERT, UPDATE or DELETE statement within the same trigger. 2487** 2488** If a separate thread makes changes on the same database connection 2489** while [sqlite3_changes()] is running then the value returned 2490** is unpredictable and not meaningful. 2491** 2492** See also: 2493** <ul> 2494** <li> the [sqlite3_total_changes()] interface 2495** <li> the [count_changes pragma] 2496** <li> the [changes() SQL function] 2497** <li> the [data_version pragma] 2498** </ul> 2499*/ 2500SQLITE_API int sqlite3_changes(sqlite3*); 2501 2502/* 2503** CAPI3REF: Total Number Of Rows Modified 2504** METHOD: sqlite3 2505** 2506** ^This function returns the total number of rows inserted, modified or 2507** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2508** since the database connection was opened, including those executed as 2509** part of trigger programs. ^Executing any other type of SQL statement 2510** does not affect the value returned by sqlite3_total_changes(). 2511** 2512** ^Changes made as part of [foreign key actions] are included in the 2513** count, but those made as part of REPLACE constraint resolution are 2514** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2515** are not counted. 2516** 2517** The [sqlite3_total_changes(D)] interface only reports the number 2518** of rows that changed due to SQL statement run against database 2519** connection D. Any changes by other database connections are ignored. 2520** To detect changes against a database file from other database 2521** connections use the [PRAGMA data_version] command or the 2522** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2523** 2524** If a separate thread makes changes on the same database connection 2525** while [sqlite3_total_changes()] is running then the value 2526** returned is unpredictable and not meaningful. 2527** 2528** See also: 2529** <ul> 2530** <li> the [sqlite3_changes()] interface 2531** <li> the [count_changes pragma] 2532** <li> the [changes() SQL function] 2533** <li> the [data_version pragma] 2534** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2535** </ul> 2536*/ 2537SQLITE_API int sqlite3_total_changes(sqlite3*); 2538 2539/* 2540** CAPI3REF: Interrupt A Long-Running Query 2541** METHOD: sqlite3 2542** 2543** ^This function causes any pending database operation to abort and 2544** return at its earliest opportunity. This routine is typically 2545** called in response to a user action such as pressing "Cancel" 2546** or Ctrl-C where the user wants a long query operation to halt 2547** immediately. 2548** 2549** ^It is safe to call this routine from a thread different from the 2550** thread that is currently running the database operation. But it 2551** is not safe to call this routine with a [database connection] that 2552** is closed or might close before sqlite3_interrupt() returns. 2553** 2554** ^If an SQL operation is very nearly finished at the time when 2555** sqlite3_interrupt() is called, then it might not have an opportunity 2556** to be interrupted and might continue to completion. 2557** 2558** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2559** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2560** that is inside an explicit transaction, then the entire transaction 2561** will be rolled back automatically. 2562** 2563** ^The sqlite3_interrupt(D) call is in effect until all currently running 2564** SQL statements on [database connection] D complete. ^Any new SQL statements 2565** that are started after the sqlite3_interrupt() call and before the 2566** running statement count reaches zero are interrupted as if they had been 2567** running prior to the sqlite3_interrupt() call. ^New SQL statements 2568** that are started after the running statement count reaches zero are 2569** not effected by the sqlite3_interrupt(). 2570** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2571** SQL statements is a no-op and has no effect on SQL statements 2572** that are started after the sqlite3_interrupt() call returns. 2573*/ 2574SQLITE_API void sqlite3_interrupt(sqlite3*); 2575 2576/* 2577** CAPI3REF: Determine If An SQL Statement Is Complete 2578** 2579** These routines are useful during command-line input to determine if the 2580** currently entered text seems to form a complete SQL statement or 2581** if additional input is needed before sending the text into 2582** SQLite for parsing. ^These routines return 1 if the input string 2583** appears to be a complete SQL statement. ^A statement is judged to be 2584** complete if it ends with a semicolon token and is not a prefix of a 2585** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2586** string literals or quoted identifier names or comments are not 2587** independent tokens (they are part of the token in which they are 2588** embedded) and thus do not count as a statement terminator. ^Whitespace 2589** and comments that follow the final semicolon are ignored. 2590** 2591** ^These routines return 0 if the statement is incomplete. ^If a 2592** memory allocation fails, then SQLITE_NOMEM is returned. 2593** 2594** ^These routines do not parse the SQL statements thus 2595** will not detect syntactically incorrect SQL. 2596** 2597** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2598** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2599** automatically by sqlite3_complete16(). If that initialization fails, 2600** then the return value from sqlite3_complete16() will be non-zero 2601** regardless of whether or not the input SQL is complete.)^ 2602** 2603** The input to [sqlite3_complete()] must be a zero-terminated 2604** UTF-8 string. 2605** 2606** The input to [sqlite3_complete16()] must be a zero-terminated 2607** UTF-16 string in native byte order. 2608*/ 2609SQLITE_API int sqlite3_complete(const char *sql); 2610SQLITE_API int sqlite3_complete16(const void *sql); 2611 2612/* 2613** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2614** KEYWORDS: {busy-handler callback} {busy handler} 2615** METHOD: sqlite3 2616** 2617** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2618** that might be invoked with argument P whenever 2619** an attempt is made to access a database table associated with 2620** [database connection] D when another thread 2621** or process has the table locked. 2622** The sqlite3_busy_handler() interface is used to implement 2623** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2624** 2625** ^If the busy callback is NULL, then [SQLITE_BUSY] 2626** is returned immediately upon encountering the lock. ^If the busy callback 2627** is not NULL, then the callback might be invoked with two arguments. 2628** 2629** ^The first argument to the busy handler is a copy of the void* pointer which 2630** is the third argument to sqlite3_busy_handler(). ^The second argument to 2631** the busy handler callback is the number of times that the busy handler has 2632** been invoked previously for the same locking event. ^If the 2633** busy callback returns 0, then no additional attempts are made to 2634** access the database and [SQLITE_BUSY] is returned 2635** to the application. 2636** ^If the callback returns non-zero, then another attempt 2637** is made to access the database and the cycle repeats. 2638** 2639** The presence of a busy handler does not guarantee that it will be invoked 2640** when there is lock contention. ^If SQLite determines that invoking the busy 2641** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2642** to the application instead of invoking the 2643** busy handler. 2644** Consider a scenario where one process is holding a read lock that 2645** it is trying to promote to a reserved lock and 2646** a second process is holding a reserved lock that it is trying 2647** to promote to an exclusive lock. The first process cannot proceed 2648** because it is blocked by the second and the second process cannot 2649** proceed because it is blocked by the first. If both processes 2650** invoke the busy handlers, neither will make any progress. Therefore, 2651** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2652** will induce the first process to release its read lock and allow 2653** the second process to proceed. 2654** 2655** ^The default busy callback is NULL. 2656** 2657** ^(There can only be a single busy handler defined for each 2658** [database connection]. Setting a new busy handler clears any 2659** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2660** or evaluating [PRAGMA busy_timeout=N] will change the 2661** busy handler and thus clear any previously set busy handler. 2662** 2663** The busy callback should not take any actions which modify the 2664** database connection that invoked the busy handler. In other words, 2665** the busy handler is not reentrant. Any such actions 2666** result in undefined behavior. 2667** 2668** A busy handler must not close the database connection 2669** or [prepared statement] that invoked the busy handler. 2670*/ 2671SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2672 2673/* 2674** CAPI3REF: Set A Busy Timeout 2675** METHOD: sqlite3 2676** 2677** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2678** for a specified amount of time when a table is locked. ^The handler 2679** will sleep multiple times until at least "ms" milliseconds of sleeping 2680** have accumulated. ^After at least "ms" milliseconds of sleeping, 2681** the handler returns 0 which causes [sqlite3_step()] to return 2682** [SQLITE_BUSY]. 2683** 2684** ^Calling this routine with an argument less than or equal to zero 2685** turns off all busy handlers. 2686** 2687** ^(There can only be a single busy handler for a particular 2688** [database connection] at any given moment. If another busy handler 2689** was defined (using [sqlite3_busy_handler()]) prior to calling 2690** this routine, that other busy handler is cleared.)^ 2691** 2692** See also: [PRAGMA busy_timeout] 2693*/ 2694SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2695 2696/* 2697** CAPI3REF: Convenience Routines For Running Queries 2698** METHOD: sqlite3 2699** 2700** This is a legacy interface that is preserved for backwards compatibility. 2701** Use of this interface is not recommended. 2702** 2703** Definition: A <b>result table</b> is memory data structure created by the 2704** [sqlite3_get_table()] interface. A result table records the 2705** complete query results from one or more queries. 2706** 2707** The table conceptually has a number of rows and columns. But 2708** these numbers are not part of the result table itself. These 2709** numbers are obtained separately. Let N be the number of rows 2710** and M be the number of columns. 2711** 2712** A result table is an array of pointers to zero-terminated UTF-8 strings. 2713** There are (N+1)*M elements in the array. The first M pointers point 2714** to zero-terminated strings that contain the names of the columns. 2715** The remaining entries all point to query results. NULL values result 2716** in NULL pointers. All other values are in their UTF-8 zero-terminated 2717** string representation as returned by [sqlite3_column_text()]. 2718** 2719** A result table might consist of one or more memory allocations. 2720** It is not safe to pass a result table directly to [sqlite3_free()]. 2721** A result table should be deallocated using [sqlite3_free_table()]. 2722** 2723** ^(As an example of the result table format, suppose a query result 2724** is as follows: 2725** 2726** <blockquote><pre> 2727** Name | Age 2728** ----------------------- 2729** Alice | 43 2730** Bob | 28 2731** Cindy | 21 2732** </pre></blockquote> 2733** 2734** There are two columns (M==2) and three rows (N==3). Thus the 2735** result table has 8 entries. Suppose the result table is stored 2736** in an array named azResult. Then azResult holds this content: 2737** 2738** <blockquote><pre> 2739** azResult[0] = "Name"; 2740** azResult[1] = "Age"; 2741** azResult[2] = "Alice"; 2742** azResult[3] = "43"; 2743** azResult[4] = "Bob"; 2744** azResult[5] = "28"; 2745** azResult[6] = "Cindy"; 2746** azResult[7] = "21"; 2747** </pre></blockquote>)^ 2748** 2749** ^The sqlite3_get_table() function evaluates one or more 2750** semicolon-separated SQL statements in the zero-terminated UTF-8 2751** string of its 2nd parameter and returns a result table to the 2752** pointer given in its 3rd parameter. 2753** 2754** After the application has finished with the result from sqlite3_get_table(), 2755** it must pass the result table pointer to sqlite3_free_table() in order to 2756** release the memory that was malloced. Because of the way the 2757** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2758** function must not try to call [sqlite3_free()] directly. Only 2759** [sqlite3_free_table()] is able to release the memory properly and safely. 2760** 2761** The sqlite3_get_table() interface is implemented as a wrapper around 2762** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2763** to any internal data structures of SQLite. It uses only the public 2764** interface defined here. As a consequence, errors that occur in the 2765** wrapper layer outside of the internal [sqlite3_exec()] call are not 2766** reflected in subsequent calls to [sqlite3_errcode()] or 2767** [sqlite3_errmsg()]. 2768*/ 2769SQLITE_API int sqlite3_get_table( 2770 sqlite3 *db, /* An open database */ 2771 const char *zSql, /* SQL to be evaluated */ 2772 char ***pazResult, /* Results of the query */ 2773 int *pnRow, /* Number of result rows written here */ 2774 int *pnColumn, /* Number of result columns written here */ 2775 char **pzErrmsg /* Error msg written here */ 2776); 2777SQLITE_API void sqlite3_free_table(char **result); 2778 2779/* 2780** CAPI3REF: Formatted String Printing Functions 2781** 2782** These routines are work-alikes of the "printf()" family of functions 2783** from the standard C library. 2784** These routines understand most of the common formatting options from 2785** the standard library printf() 2786** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2787** See the [built-in printf()] documentation for details. 2788** 2789** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2790** results into memory obtained from [sqlite3_malloc64()]. 2791** The strings returned by these two routines should be 2792** released by [sqlite3_free()]. ^Both routines return a 2793** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2794** memory to hold the resulting string. 2795** 2796** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2797** the standard C library. The result is written into the 2798** buffer supplied as the second parameter whose size is given by 2799** the first parameter. Note that the order of the 2800** first two parameters is reversed from snprintf().)^ This is an 2801** historical accident that cannot be fixed without breaking 2802** backwards compatibility. ^(Note also that sqlite3_snprintf() 2803** returns a pointer to its buffer instead of the number of 2804** characters actually written into the buffer.)^ We admit that 2805** the number of characters written would be a more useful return 2806** value but we cannot change the implementation of sqlite3_snprintf() 2807** now without breaking compatibility. 2808** 2809** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2810** guarantees that the buffer is always zero-terminated. ^The first 2811** parameter "n" is the total size of the buffer, including space for 2812** the zero terminator. So the longest string that can be completely 2813** written will be n-1 characters. 2814** 2815** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2816** 2817** See also: [built-in printf()], [printf() SQL function] 2818*/ 2819SQLITE_API char *sqlite3_mprintf(const char*,...); 2820SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2821SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2822SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2823 2824/* 2825** CAPI3REF: Memory Allocation Subsystem 2826** 2827** The SQLite core uses these three routines for all of its own 2828** internal memory allocation needs. "Core" in the previous sentence 2829** does not include operating-system specific [VFS] implementation. The 2830** Windows VFS uses native malloc() and free() for some operations. 2831** 2832** ^The sqlite3_malloc() routine returns a pointer to a block 2833** of memory at least N bytes in length, where N is the parameter. 2834** ^If sqlite3_malloc() is unable to obtain sufficient free 2835** memory, it returns a NULL pointer. ^If the parameter N to 2836** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2837** a NULL pointer. 2838** 2839** ^The sqlite3_malloc64(N) routine works just like 2840** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2841** of a signed 32-bit integer. 2842** 2843** ^Calling sqlite3_free() with a pointer previously returned 2844** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2845** that it might be reused. ^The sqlite3_free() routine is 2846** a no-op if is called with a NULL pointer. Passing a NULL pointer 2847** to sqlite3_free() is harmless. After being freed, memory 2848** should neither be read nor written. Even reading previously freed 2849** memory might result in a segmentation fault or other severe error. 2850** Memory corruption, a segmentation fault, or other severe error 2851** might result if sqlite3_free() is called with a non-NULL pointer that 2852** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2853** 2854** ^The sqlite3_realloc(X,N) interface attempts to resize a 2855** prior memory allocation X to be at least N bytes. 2856** ^If the X parameter to sqlite3_realloc(X,N) 2857** is a NULL pointer then its behavior is identical to calling 2858** sqlite3_malloc(N). 2859** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2860** negative then the behavior is exactly the same as calling 2861** sqlite3_free(X). 2862** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2863** of at least N bytes in size or NULL if insufficient memory is available. 2864** ^If M is the size of the prior allocation, then min(N,M) bytes 2865** of the prior allocation are copied into the beginning of buffer returned 2866** by sqlite3_realloc(X,N) and the prior allocation is freed. 2867** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2868** prior allocation is not freed. 2869** 2870** ^The sqlite3_realloc64(X,N) interfaces works the same as 2871** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2872** of a 32-bit signed integer. 2873** 2874** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2875** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2876** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2877** ^The value returned by sqlite3_msize(X) might be larger than the number 2878** of bytes requested when X was allocated. ^If X is a NULL pointer then 2879** sqlite3_msize(X) returns zero. If X points to something that is not 2880** the beginning of memory allocation, or if it points to a formerly 2881** valid memory allocation that has now been freed, then the behavior 2882** of sqlite3_msize(X) is undefined and possibly harmful. 2883** 2884** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2885** sqlite3_malloc64(), and sqlite3_realloc64() 2886** is always aligned to at least an 8 byte boundary, or to a 2887** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2888** option is used. 2889** 2890** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2891** must be either NULL or else pointers obtained from a prior 2892** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2893** not yet been released. 2894** 2895** The application must not read or write any part of 2896** a block of memory after it has been released using 2897** [sqlite3_free()] or [sqlite3_realloc()]. 2898*/ 2899SQLITE_API void *sqlite3_malloc(int); 2900SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2901SQLITE_API void *sqlite3_realloc(void*, int); 2902SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2903SQLITE_API void sqlite3_free(void*); 2904SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2905 2906/* 2907** CAPI3REF: Memory Allocator Statistics 2908** 2909** SQLite provides these two interfaces for reporting on the status 2910** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2911** routines, which form the built-in memory allocation subsystem. 2912** 2913** ^The [sqlite3_memory_used()] routine returns the number of bytes 2914** of memory currently outstanding (malloced but not freed). 2915** ^The [sqlite3_memory_highwater()] routine returns the maximum 2916** value of [sqlite3_memory_used()] since the high-water mark 2917** was last reset. ^The values returned by [sqlite3_memory_used()] and 2918** [sqlite3_memory_highwater()] include any overhead 2919** added by SQLite in its implementation of [sqlite3_malloc()], 2920** but not overhead added by the any underlying system library 2921** routines that [sqlite3_malloc()] may call. 2922** 2923** ^The memory high-water mark is reset to the current value of 2924** [sqlite3_memory_used()] if and only if the parameter to 2925** [sqlite3_memory_highwater()] is true. ^The value returned 2926** by [sqlite3_memory_highwater(1)] is the high-water mark 2927** prior to the reset. 2928*/ 2929SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2930SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2931 2932/* 2933** CAPI3REF: Pseudo-Random Number Generator 2934** 2935** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2936** select random [ROWID | ROWIDs] when inserting new records into a table that 2937** already uses the largest possible [ROWID]. The PRNG is also used for 2938** the built-in random() and randomblob() SQL functions. This interface allows 2939** applications to access the same PRNG for other purposes. 2940** 2941** ^A call to this routine stores N bytes of randomness into buffer P. 2942** ^The P parameter can be a NULL pointer. 2943** 2944** ^If this routine has not been previously called or if the previous 2945** call had N less than one or a NULL pointer for P, then the PRNG is 2946** seeded using randomness obtained from the xRandomness method of 2947** the default [sqlite3_vfs] object. 2948** ^If the previous call to this routine had an N of 1 or more and a 2949** non-NULL P then the pseudo-randomness is generated 2950** internally and without recourse to the [sqlite3_vfs] xRandomness 2951** method. 2952*/ 2953SQLITE_API void sqlite3_randomness(int N, void *P); 2954 2955/* 2956** CAPI3REF: Compile-Time Authorization Callbacks 2957** METHOD: sqlite3 2958** KEYWORDS: {authorizer callback} 2959** 2960** ^This routine registers an authorizer callback with a particular 2961** [database connection], supplied in the first argument. 2962** ^The authorizer callback is invoked as SQL statements are being compiled 2963** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2964** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2965** and [sqlite3_prepare16_v3()]. ^At various 2966** points during the compilation process, as logic is being created 2967** to perform various actions, the authorizer callback is invoked to 2968** see if those actions are allowed. ^The authorizer callback should 2969** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2970** specific action but allow the SQL statement to continue to be 2971** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2972** rejected with an error. ^If the authorizer callback returns 2973** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2974** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2975** the authorizer will fail with an error message. 2976** 2977** When the callback returns [SQLITE_OK], that means the operation 2978** requested is ok. ^When the callback returns [SQLITE_DENY], the 2979** [sqlite3_prepare_v2()] or equivalent call that triggered the 2980** authorizer will fail with an error message explaining that 2981** access is denied. 2982** 2983** ^The first parameter to the authorizer callback is a copy of the third 2984** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2985** to the callback is an integer [SQLITE_COPY | action code] that specifies 2986** the particular action to be authorized. ^The third through sixth parameters 2987** to the callback are either NULL pointers or zero-terminated strings 2988** that contain additional details about the action to be authorized. 2989** Applications must always be prepared to encounter a NULL pointer in any 2990** of the third through the sixth parameters of the authorization callback. 2991** 2992** ^If the action code is [SQLITE_READ] 2993** and the callback returns [SQLITE_IGNORE] then the 2994** [prepared statement] statement is constructed to substitute 2995** a NULL value in place of the table column that would have 2996** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2997** return can be used to deny an untrusted user access to individual 2998** columns of a table. 2999** ^When a table is referenced by a [SELECT] but no column values are 3000** extracted from that table (for example in a query like 3001** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3002** is invoked once for that table with a column name that is an empty string. 3003** ^If the action code is [SQLITE_DELETE] and the callback returns 3004** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3005** [truncate optimization] is disabled and all rows are deleted individually. 3006** 3007** An authorizer is used when [sqlite3_prepare | preparing] 3008** SQL statements from an untrusted source, to ensure that the SQL statements 3009** do not try to access data they are not allowed to see, or that they do not 3010** try to execute malicious statements that damage the database. For 3011** example, an application may allow a user to enter arbitrary 3012** SQL queries for evaluation by a database. But the application does 3013** not want the user to be able to make arbitrary changes to the 3014** database. An authorizer could then be put in place while the 3015** user-entered SQL is being [sqlite3_prepare | prepared] that 3016** disallows everything except [SELECT] statements. 3017** 3018** Applications that need to process SQL from untrusted sources 3019** might also consider lowering resource limits using [sqlite3_limit()] 3020** and limiting database size using the [max_page_count] [PRAGMA] 3021** in addition to using an authorizer. 3022** 3023** ^(Only a single authorizer can be in place on a database connection 3024** at a time. Each call to sqlite3_set_authorizer overrides the 3025** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3026** The authorizer is disabled by default. 3027** 3028** The authorizer callback must not do anything that will modify 3029** the database connection that invoked the authorizer callback. 3030** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3031** database connections for the meaning of "modify" in this paragraph. 3032** 3033** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3034** statement might be re-prepared during [sqlite3_step()] due to a 3035** schema change. Hence, the application should ensure that the 3036** correct authorizer callback remains in place during the [sqlite3_step()]. 3037** 3038** ^Note that the authorizer callback is invoked only during 3039** [sqlite3_prepare()] or its variants. Authorization is not 3040** performed during statement evaluation in [sqlite3_step()], unless 3041** as stated in the previous paragraph, sqlite3_step() invokes 3042** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3043*/ 3044SQLITE_API int sqlite3_set_authorizer( 3045 sqlite3*, 3046 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3047 void *pUserData 3048); 3049 3050/* 3051** CAPI3REF: Authorizer Return Codes 3052** 3053** The [sqlite3_set_authorizer | authorizer callback function] must 3054** return either [SQLITE_OK] or one of these two constants in order 3055** to signal SQLite whether or not the action is permitted. See the 3056** [sqlite3_set_authorizer | authorizer documentation] for additional 3057** information. 3058** 3059** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3060** returned from the [sqlite3_vtab_on_conflict()] interface. 3061*/ 3062#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3063#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3064 3065/* 3066** CAPI3REF: Authorizer Action Codes 3067** 3068** The [sqlite3_set_authorizer()] interface registers a callback function 3069** that is invoked to authorize certain SQL statement actions. The 3070** second parameter to the callback is an integer code that specifies 3071** what action is being authorized. These are the integer action codes that 3072** the authorizer callback may be passed. 3073** 3074** These action code values signify what kind of operation is to be 3075** authorized. The 3rd and 4th parameters to the authorization 3076** callback function will be parameters or NULL depending on which of these 3077** codes is used as the second parameter. ^(The 5th parameter to the 3078** authorizer callback is the name of the database ("main", "temp", 3079** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3080** is the name of the inner-most trigger or view that is responsible for 3081** the access attempt or NULL if this access attempt is directly from 3082** top-level SQL code. 3083*/ 3084/******************************************* 3rd ************ 4th ***********/ 3085#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3086#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3087#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3088#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3089#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3090#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3091#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3092#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3093#define SQLITE_DELETE 9 /* Table Name NULL */ 3094#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3095#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3096#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3097#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3098#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3099#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3100#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3101#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3102#define SQLITE_INSERT 18 /* Table Name NULL */ 3103#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3104#define SQLITE_READ 20 /* Table Name Column Name */ 3105#define SQLITE_SELECT 21 /* NULL NULL */ 3106#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3107#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3108#define SQLITE_ATTACH 24 /* Filename NULL */ 3109#define SQLITE_DETACH 25 /* Database Name NULL */ 3110#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3111#define SQLITE_REINDEX 27 /* Index Name NULL */ 3112#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3113#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3114#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3115#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3116#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3117#define SQLITE_COPY 0 /* No longer used */ 3118#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3119 3120/* 3121** CAPI3REF: Tracing And Profiling Functions 3122** METHOD: sqlite3 3123** 3124** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3125** instead of the routines described here. 3126** 3127** These routines register callback functions that can be used for 3128** tracing and profiling the execution of SQL statements. 3129** 3130** ^The callback function registered by sqlite3_trace() is invoked at 3131** various times when an SQL statement is being run by [sqlite3_step()]. 3132** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3133** SQL statement text as the statement first begins executing. 3134** ^(Additional sqlite3_trace() callbacks might occur 3135** as each triggered subprogram is entered. The callbacks for triggers 3136** contain a UTF-8 SQL comment that identifies the trigger.)^ 3137** 3138** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3139** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3140** 3141** ^The callback function registered by sqlite3_profile() is invoked 3142** as each SQL statement finishes. ^The profile callback contains 3143** the original statement text and an estimate of wall-clock time 3144** of how long that statement took to run. ^The profile callback 3145** time is in units of nanoseconds, however the current implementation 3146** is only capable of millisecond resolution so the six least significant 3147** digits in the time are meaningless. Future versions of SQLite 3148** might provide greater resolution on the profiler callback. Invoking 3149** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3150** profile callback. 3151*/ 3152SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3153 void(*xTrace)(void*,const char*), void*); 3154SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3155 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3156 3157/* 3158** CAPI3REF: SQL Trace Event Codes 3159** KEYWORDS: SQLITE_TRACE 3160** 3161** These constants identify classes of events that can be monitored 3162** using the [sqlite3_trace_v2()] tracing logic. The M argument 3163** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3164** the following constants. ^The first argument to the trace callback 3165** is one of the following constants. 3166** 3167** New tracing constants may be added in future releases. 3168** 3169** ^A trace callback has four arguments: xCallback(T,C,P,X). 3170** ^The T argument is one of the integer type codes above. 3171** ^The C argument is a copy of the context pointer passed in as the 3172** fourth argument to [sqlite3_trace_v2()]. 3173** The P and X arguments are pointers whose meanings depend on T. 3174** 3175** <dl> 3176** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3177** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3178** first begins running and possibly at other times during the 3179** execution of the prepared statement, such as at the start of each 3180** trigger subprogram. ^The P argument is a pointer to the 3181** [prepared statement]. ^The X argument is a pointer to a string which 3182** is the unexpanded SQL text of the prepared statement or an SQL comment 3183** that indicates the invocation of a trigger. ^The callback can compute 3184** the same text that would have been returned by the legacy [sqlite3_trace()] 3185** interface by using the X argument when X begins with "--" and invoking 3186** [sqlite3_expanded_sql(P)] otherwise. 3187** 3188** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3189** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3190** information as is provided by the [sqlite3_profile()] callback. 3191** ^The P argument is a pointer to the [prepared statement] and the 3192** X argument points to a 64-bit integer which is the estimated of 3193** the number of nanosecond that the prepared statement took to run. 3194** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3195** 3196** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3197** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3198** statement generates a single row of result. 3199** ^The P argument is a pointer to the [prepared statement] and the 3200** X argument is unused. 3201** 3202** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3203** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3204** connection closes. 3205** ^The P argument is a pointer to the [database connection] object 3206** and the X argument is unused. 3207** </dl> 3208*/ 3209#define SQLITE_TRACE_STMT 0x01 3210#define SQLITE_TRACE_PROFILE 0x02 3211#define SQLITE_TRACE_ROW 0x04 3212#define SQLITE_TRACE_CLOSE 0x08 3213 3214/* 3215** CAPI3REF: SQL Trace Hook 3216** METHOD: sqlite3 3217** 3218** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3219** function X against [database connection] D, using property mask M 3220** and context pointer P. ^If the X callback is 3221** NULL or if the M mask is zero, then tracing is disabled. The 3222** M argument should be the bitwise OR-ed combination of 3223** zero or more [SQLITE_TRACE] constants. 3224** 3225** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3226** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3227** 3228** ^The X callback is invoked whenever any of the events identified by 3229** mask M occur. ^The integer return value from the callback is currently 3230** ignored, though this may change in future releases. Callback 3231** implementations should return zero to ensure future compatibility. 3232** 3233** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3234** ^The T argument is one of the [SQLITE_TRACE] 3235** constants to indicate why the callback was invoked. 3236** ^The C argument is a copy of the context pointer. 3237** The P and X arguments are pointers whose meanings depend on T. 3238** 3239** The sqlite3_trace_v2() interface is intended to replace the legacy 3240** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3241** are deprecated. 3242*/ 3243SQLITE_API int sqlite3_trace_v2( 3244 sqlite3*, 3245 unsigned uMask, 3246 int(*xCallback)(unsigned,void*,void*,void*), 3247 void *pCtx 3248); 3249 3250/* 3251** CAPI3REF: Query Progress Callbacks 3252** METHOD: sqlite3 3253** 3254** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3255** function X to be invoked periodically during long running calls to 3256** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3257** database connection D. An example use for this 3258** interface is to keep a GUI updated during a large query. 3259** 3260** ^The parameter P is passed through as the only parameter to the 3261** callback function X. ^The parameter N is the approximate number of 3262** [virtual machine instructions] that are evaluated between successive 3263** invocations of the callback X. ^If N is less than one then the progress 3264** handler is disabled. 3265** 3266** ^Only a single progress handler may be defined at one time per 3267** [database connection]; setting a new progress handler cancels the 3268** old one. ^Setting parameter X to NULL disables the progress handler. 3269** ^The progress handler is also disabled by setting N to a value less 3270** than 1. 3271** 3272** ^If the progress callback returns non-zero, the operation is 3273** interrupted. This feature can be used to implement a 3274** "Cancel" button on a GUI progress dialog box. 3275** 3276** The progress handler callback must not do anything that will modify 3277** the database connection that invoked the progress handler. 3278** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3279** database connections for the meaning of "modify" in this paragraph. 3280** 3281*/ 3282SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3283 3284/* 3285** CAPI3REF: Opening A New Database Connection 3286** CONSTRUCTOR: sqlite3 3287** 3288** ^These routines open an SQLite database file as specified by the 3289** filename argument. ^The filename argument is interpreted as UTF-8 for 3290** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3291** order for sqlite3_open16(). ^(A [database connection] handle is usually 3292** returned in *ppDb, even if an error occurs. The only exception is that 3293** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3294** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3295** object.)^ ^(If the database is opened (and/or created) successfully, then 3296** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3297** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3298** an English language description of the error following a failure of any 3299** of the sqlite3_open() routines. 3300** 3301** ^The default encoding will be UTF-8 for databases created using 3302** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3303** created using sqlite3_open16() will be UTF-16 in the native byte order. 3304** 3305** Whether or not an error occurs when it is opened, resources 3306** associated with the [database connection] handle should be released by 3307** passing it to [sqlite3_close()] when it is no longer required. 3308** 3309** The sqlite3_open_v2() interface works like sqlite3_open() 3310** except that it accepts two additional parameters for additional control 3311** over the new database connection. ^(The flags parameter to 3312** sqlite3_open_v2() must include, at a minimum, one of the following 3313** three flag combinations:)^ 3314** 3315** <dl> 3316** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3317** <dd>The database is opened in read-only mode. If the database does not 3318** already exist, an error is returned.</dd>)^ 3319** 3320** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3321** <dd>The database is opened for reading and writing if possible, or reading 3322** only if the file is write protected by the operating system. In either 3323** case the database must already exist, otherwise an error is returned.</dd>)^ 3324** 3325** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3326** <dd>The database is opened for reading and writing, and is created if 3327** it does not already exist. This is the behavior that is always used for 3328** sqlite3_open() and sqlite3_open16().</dd>)^ 3329** </dl> 3330** 3331** In addition to the required flags, the following optional flags are 3332** also supported: 3333** 3334** <dl> 3335** ^(<dt>[SQLITE_OPEN_URI]</dt> 3336** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3337** 3338** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3339** <dd>The database will be opened as an in-memory database. The database 3340** is named by the "filename" argument for the purposes of cache-sharing, 3341** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3342** </dd>)^ 3343** 3344** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3345** <dd>The new database connection will use the "multi-thread" 3346** [threading mode].)^ This means that separate threads are allowed 3347** to use SQLite at the same time, as long as each thread is using 3348** a different [database connection]. 3349** 3350** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3351** <dd>The new database connection will use the "serialized" 3352** [threading mode].)^ This means the multiple threads can safely 3353** attempt to use the same database connection at the same time. 3354** (Mutexes will block any actual concurrency, but in this mode 3355** there is no harm in trying.) 3356** 3357** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3358** <dd>The database is opened [shared cache] enabled, overriding 3359** the default shared cache setting provided by 3360** [sqlite3_enable_shared_cache()].)^ 3361** 3362** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3363** <dd>The database is opened [shared cache] disabled, overriding 3364** the default shared cache setting provided by 3365** [sqlite3_enable_shared_cache()].)^ 3366** 3367** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3368** <dd>The database filename is not allowed to be a symbolic link</dd> 3369** </dl>)^ 3370** 3371** If the 3rd parameter to sqlite3_open_v2() is not one of the 3372** required combinations shown above optionally combined with other 3373** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3374** then the behavior is undefined. 3375** 3376** ^The fourth parameter to sqlite3_open_v2() is the name of the 3377** [sqlite3_vfs] object that defines the operating system interface that 3378** the new database connection should use. ^If the fourth parameter is 3379** a NULL pointer then the default [sqlite3_vfs] object is used. 3380** 3381** ^If the filename is ":memory:", then a private, temporary in-memory database 3382** is created for the connection. ^This in-memory database will vanish when 3383** the database connection is closed. Future versions of SQLite might 3384** make use of additional special filenames that begin with the ":" character. 3385** It is recommended that when a database filename actually does begin with 3386** a ":" character you should prefix the filename with a pathname such as 3387** "./" to avoid ambiguity. 3388** 3389** ^If the filename is an empty string, then a private, temporary 3390** on-disk database will be created. ^This private database will be 3391** automatically deleted as soon as the database connection is closed. 3392** 3393** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3394** 3395** ^If [URI filename] interpretation is enabled, and the filename argument 3396** begins with "file:", then the filename is interpreted as a URI. ^URI 3397** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3398** set in the third argument to sqlite3_open_v2(), or if it has 3399** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3400** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3401** URI filename interpretation is turned off 3402** by default, but future releases of SQLite might enable URI filename 3403** interpretation by default. See "[URI filenames]" for additional 3404** information. 3405** 3406** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3407** authority, then it must be either an empty string or the string 3408** "localhost". ^If the authority is not an empty string or "localhost", an 3409** error is returned to the caller. ^The fragment component of a URI, if 3410** present, is ignored. 3411** 3412** ^SQLite uses the path component of the URI as the name of the disk file 3413** which contains the database. ^If the path begins with a '/' character, 3414** then it is interpreted as an absolute path. ^If the path does not begin 3415** with a '/' (meaning that the authority section is omitted from the URI) 3416** then the path is interpreted as a relative path. 3417** ^(On windows, the first component of an absolute path 3418** is a drive specification (e.g. "C:").)^ 3419** 3420** [[core URI query parameters]] 3421** The query component of a URI may contain parameters that are interpreted 3422** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3423** SQLite and its built-in [VFSes] interpret the 3424** following query parameters: 3425** 3426** <ul> 3427** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3428** a VFS object that provides the operating system interface that should 3429** be used to access the database file on disk. ^If this option is set to 3430** an empty string the default VFS object is used. ^Specifying an unknown 3431** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3432** present, then the VFS specified by the option takes precedence over 3433** the value passed as the fourth parameter to sqlite3_open_v2(). 3434** 3435** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3436** "rwc", or "memory". Attempting to set it to any other value is 3437** an error)^. 3438** ^If "ro" is specified, then the database is opened for read-only 3439** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3440** third argument to sqlite3_open_v2(). ^If the mode option is set to 3441** "rw", then the database is opened for read-write (but not create) 3442** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3443** been set. ^Value "rwc" is equivalent to setting both 3444** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3445** set to "memory" then a pure [in-memory database] that never reads 3446** or writes from disk is used. ^It is an error to specify a value for 3447** the mode parameter that is less restrictive than that specified by 3448** the flags passed in the third parameter to sqlite3_open_v2(). 3449** 3450** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3451** "private". ^Setting it to "shared" is equivalent to setting the 3452** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3453** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3454** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3455** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3456** a URI filename, its value overrides any behavior requested by setting 3457** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3458** 3459** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3460** [powersafe overwrite] property does or does not apply to the 3461** storage media on which the database file resides. 3462** 3463** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3464** which if set disables file locking in rollback journal modes. This 3465** is useful for accessing a database on a filesystem that does not 3466** support locking. Caution: Database corruption might result if two 3467** or more processes write to the same database and any one of those 3468** processes uses nolock=1. 3469** 3470** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3471** parameter that indicates that the database file is stored on 3472** read-only media. ^When immutable is set, SQLite assumes that the 3473** database file cannot be changed, even by a process with higher 3474** privilege, and so the database is opened read-only and all locking 3475** and change detection is disabled. Caution: Setting the immutable 3476** property on a database file that does in fact change can result 3477** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3478** See also: [SQLITE_IOCAP_IMMUTABLE]. 3479** 3480** </ul> 3481** 3482** ^Specifying an unknown parameter in the query component of a URI is not an 3483** error. Future versions of SQLite might understand additional query 3484** parameters. See "[query parameters with special meaning to SQLite]" for 3485** additional information. 3486** 3487** [[URI filename examples]] <h3>URI filename examples</h3> 3488** 3489** <table border="1" align=center cellpadding=5> 3490** <tr><th> URI filenames <th> Results 3491** <tr><td> file:data.db <td> 3492** Open the file "data.db" in the current directory. 3493** <tr><td> file:/home/fred/data.db<br> 3494** file:///home/fred/data.db <br> 3495** file://localhost/home/fred/data.db <br> <td> 3496** Open the database file "/home/fred/data.db". 3497** <tr><td> file://darkstar/home/fred/data.db <td> 3498** An error. "darkstar" is not a recognized authority. 3499** <tr><td style="white-space:nowrap"> 3500** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3501** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3502** C:. Note that the %20 escaping in this example is not strictly 3503** necessary - space characters can be used literally 3504** in URI filenames. 3505** <tr><td> file:data.db?mode=ro&cache=private <td> 3506** Open file "data.db" in the current directory for read-only access. 3507** Regardless of whether or not shared-cache mode is enabled by 3508** default, use a private cache. 3509** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3510** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3511** that uses dot-files in place of posix advisory locking. 3512** <tr><td> file:data.db?mode=readonly <td> 3513** An error. "readonly" is not a valid option for the "mode" parameter. 3514** Use "ro" instead: "file:data.db?mode=ro". 3515** </table> 3516** 3517** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3518** query components of a URI. A hexadecimal escape sequence consists of a 3519** percent sign - "%" - followed by exactly two hexadecimal digits 3520** specifying an octet value. ^Before the path or query components of a 3521** URI filename are interpreted, they are encoded using UTF-8 and all 3522** hexadecimal escape sequences replaced by a single byte containing the 3523** corresponding octet. If this process generates an invalid UTF-8 encoding, 3524** the results are undefined. 3525** 3526** <b>Note to Windows users:</b> The encoding used for the filename argument 3527** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3528** codepage is currently defined. Filenames containing international 3529** characters must be converted to UTF-8 prior to passing them into 3530** sqlite3_open() or sqlite3_open_v2(). 3531** 3532** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3533** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3534** features that require the use of temporary files may fail. 3535** 3536** See also: [sqlite3_temp_directory] 3537*/ 3538SQLITE_API int sqlite3_open( 3539 const char *filename, /* Database filename (UTF-8) */ 3540 sqlite3 **ppDb /* OUT: SQLite db handle */ 3541); 3542SQLITE_API int sqlite3_open16( 3543 const void *filename, /* Database filename (UTF-16) */ 3544 sqlite3 **ppDb /* OUT: SQLite db handle */ 3545); 3546SQLITE_API int sqlite3_open_v2( 3547 const char *filename, /* Database filename (UTF-8) */ 3548 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3549 int flags, /* Flags */ 3550 const char *zVfs /* Name of VFS module to use */ 3551); 3552 3553/* 3554** CAPI3REF: Obtain Values For URI Parameters 3555** 3556** These are utility routines, useful to [VFS|custom VFS implementations], 3557** that check if a database file was a URI that contained a specific query 3558** parameter, and if so obtains the value of that query parameter. 3559** 3560** The first parameter to these interfaces (hereafter referred to 3561** as F) must be one of: 3562** <ul> 3563** <li> A database filename pointer created by the SQLite core and 3564** passed into the xOpen() method of a VFS implemention, or 3565** <li> A filename obtained from [sqlite3_db_filename()], or 3566** <li> A new filename constructed using [sqlite3_create_filename()]. 3567** </ul> 3568** If the F parameter is not one of the above, then the behavior is 3569** undefined and probably undesirable. Older versions of SQLite were 3570** more tolerant of invalid F parameters than newer versions. 3571** 3572** If F is a suitable filename (as described in the previous paragraph) 3573** and if P is the name of the query parameter, then 3574** sqlite3_uri_parameter(F,P) returns the value of the P 3575** parameter if it exists or a NULL pointer if P does not appear as a 3576** query parameter on F. If P is a query parameter of F and it 3577** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3578** a pointer to an empty string. 3579** 3580** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3581** parameter and returns true (1) or false (0) according to the value 3582** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3583** value of query parameter P is one of "yes", "true", or "on" in any 3584** case or if the value begins with a non-zero number. The 3585** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3586** query parameter P is one of "no", "false", or "off" in any case or 3587** if the value begins with a numeric zero. If P is not a query 3588** parameter on F or if the value of P does not match any of the 3589** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3590** 3591** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3592** 64-bit signed integer and returns that integer, or D if P does not 3593** exist. If the value of P is something other than an integer, then 3594** zero is returned. 3595** 3596** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3597** the value) of the N-th query parameter for filename F, or a NULL 3598** pointer if N is less than zero or greater than the number of query 3599** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3600** the name of the first query parameter, 1 for the second parameter, and 3601** so forth. 3602** 3603** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3604** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3605** is not a database file pathname pointer that the SQLite core passed 3606** into the xOpen VFS method, then the behavior of this routine is undefined 3607** and probably undesirable. 3608** 3609** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3610** parameter can also be the name of a rollback journal file or WAL file 3611** in addition to the main database file. Prior to version 3.31.0, these 3612** routines would only work if F was the name of the main database file. 3613** When the F parameter is the name of the rollback journal or WAL file, 3614** it has access to all the same query parameters as were found on the 3615** main database file. 3616** 3617** See the [URI filename] documentation for additional information. 3618*/ 3619SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3620SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3621SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3622SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N); 3623 3624/* 3625** CAPI3REF: Translate filenames 3626** 3627** These routines are available to [VFS|custom VFS implementations] for 3628** translating filenames between the main database file, the journal file, 3629** and the WAL file. 3630** 3631** If F is the name of an sqlite database file, journal file, or WAL file 3632** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3633** returns the name of the corresponding database file. 3634** 3635** If F is the name of an sqlite database file, journal file, or WAL file 3636** passed by the SQLite core into the VFS, or if F is a database filename 3637** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3638** returns the name of the corresponding rollback journal file. 3639** 3640** If F is the name of an sqlite database file, journal file, or WAL file 3641** that was passed by the SQLite core into the VFS, or if F is a database 3642** filename obtained from [sqlite3_db_filename()], then 3643** sqlite3_filename_wal(F) returns the name of the corresponding 3644** WAL file. 3645** 3646** In all of the above, if F is not the name of a database, journal or WAL 3647** filename passed into the VFS from the SQLite core and F is not the 3648** return value from [sqlite3_db_filename()], then the result is 3649** undefined and is likely a memory access violation. 3650*/ 3651SQLITE_API const char *sqlite3_filename_database(const char*); 3652SQLITE_API const char *sqlite3_filename_journal(const char*); 3653SQLITE_API const char *sqlite3_filename_wal(const char*); 3654 3655/* 3656** CAPI3REF: Database File Corresponding To A Journal 3657** 3658** ^If X is the name of a rollback or WAL-mode journal file that is 3659** passed into the xOpen method of [sqlite3_vfs], then 3660** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3661** object that represents the main database file. 3662** 3663** This routine is intended for use in custom [VFS] implementations 3664** only. It is not a general-purpose interface. 3665** The argument sqlite3_file_object(X) must be a filename pointer that 3666** has been passed into [sqlite3_vfs].xOpen method where the 3667** flags parameter to xOpen contains one of the bits 3668** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3669** of this routine results in undefined and probably undesirable 3670** behavior. 3671*/ 3672SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3673 3674/* 3675** CAPI3REF: Create and Destroy VFS Filenames 3676** 3677** These interfces are provided for use by [VFS shim] implementations and 3678** are not useful outside of that context. 3679** 3680** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3681** database filename D with corresponding journal file J and WAL file W and 3682** with N URI parameters key/values pairs in the array P. The result from 3683** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3684** is safe to pass to routines like: 3685** <ul> 3686** <li> [sqlite3_uri_parameter()], 3687** <li> [sqlite3_uri_boolean()], 3688** <li> [sqlite3_uri_int64()], 3689** <li> [sqlite3_uri_key()], 3690** <li> [sqlite3_filename_database()], 3691** <li> [sqlite3_filename_journal()], or 3692** <li> [sqlite3_filename_wal()]. 3693** </ul> 3694** If a memory allocation error occurs, sqlite3_create_filename() might 3695** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3696** must be released by a corresponding call to sqlite3_free_filename(Y). 3697** 3698** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3699** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3700** to a key and value for a query parameter. The P parameter may be a NULL 3701** pointer if N is zero. None of the 2*N pointers in the P array may be 3702** NULL pointers and key pointers should not be empty strings. 3703** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3704** be NULL pointers, though they can be empty strings. 3705** 3706** The sqlite3_free_filename(Y) routine releases a memory allocation 3707** previously obtained from sqlite3_create_filename(). Invoking 3708** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3709** 3710** If the Y parameter to sqlite3_free_filename(Y) is anything other 3711** than a NULL pointer or a pointer previously acquired from 3712** sqlite3_create_filename(), then bad things such as heap 3713** corruption or segfaults may occur. The value Y should not be 3714** used again after sqlite3_free_filename(Y) has been called. This means 3715** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3716** then the corresponding [sqlite3_module.xClose() method should also be 3717** invoked prior to calling sqlite3_free_filename(Y). 3718*/ 3719SQLITE_API char *sqlite3_create_filename( 3720 const char *zDatabase, 3721 const char *zJournal, 3722 const char *zWal, 3723 int nParam, 3724 const char **azParam 3725); 3726SQLITE_API void sqlite3_free_filename(char*); 3727 3728/* 3729** CAPI3REF: Error Codes And Messages 3730** METHOD: sqlite3 3731** 3732** ^If the most recent sqlite3_* API call associated with 3733** [database connection] D failed, then the sqlite3_errcode(D) interface 3734** returns the numeric [result code] or [extended result code] for that 3735** API call. 3736** ^The sqlite3_extended_errcode() 3737** interface is the same except that it always returns the 3738** [extended result code] even when extended result codes are 3739** disabled. 3740** 3741** The values returned by sqlite3_errcode() and/or 3742** sqlite3_extended_errcode() might change with each API call. 3743** Except, there are some interfaces that are guaranteed to never 3744** change the value of the error code. The error-code preserving 3745** interfaces are: 3746** 3747** <ul> 3748** <li> sqlite3_errcode() 3749** <li> sqlite3_extended_errcode() 3750** <li> sqlite3_errmsg() 3751** <li> sqlite3_errmsg16() 3752** </ul> 3753** 3754** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3755** text that describes the error, as either UTF-8 or UTF-16 respectively. 3756** ^(Memory to hold the error message string is managed internally. 3757** The application does not need to worry about freeing the result. 3758** However, the error string might be overwritten or deallocated by 3759** subsequent calls to other SQLite interface functions.)^ 3760** 3761** ^The sqlite3_errstr() interface returns the English-language text 3762** that describes the [result code], as UTF-8. 3763** ^(Memory to hold the error message string is managed internally 3764** and must not be freed by the application)^. 3765** 3766** When the serialized [threading mode] is in use, it might be the 3767** case that a second error occurs on a separate thread in between 3768** the time of the first error and the call to these interfaces. 3769** When that happens, the second error will be reported since these 3770** interfaces always report the most recent result. To avoid 3771** this, each thread can obtain exclusive use of the [database connection] D 3772** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3773** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3774** all calls to the interfaces listed here are completed. 3775** 3776** If an interface fails with SQLITE_MISUSE, that means the interface 3777** was invoked incorrectly by the application. In that case, the 3778** error code and message may or may not be set. 3779*/ 3780SQLITE_API int sqlite3_errcode(sqlite3 *db); 3781SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3782SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3783SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3784SQLITE_API const char *sqlite3_errstr(int); 3785 3786/* 3787** CAPI3REF: Prepared Statement Object 3788** KEYWORDS: {prepared statement} {prepared statements} 3789** 3790** An instance of this object represents a single SQL statement that 3791** has been compiled into binary form and is ready to be evaluated. 3792** 3793** Think of each SQL statement as a separate computer program. The 3794** original SQL text is source code. A prepared statement object 3795** is the compiled object code. All SQL must be converted into a 3796** prepared statement before it can be run. 3797** 3798** The life-cycle of a prepared statement object usually goes like this: 3799** 3800** <ol> 3801** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3802** <li> Bind values to [parameters] using the sqlite3_bind_*() 3803** interfaces. 3804** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3805** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3806** to step 2. Do this zero or more times. 3807** <li> Destroy the object using [sqlite3_finalize()]. 3808** </ol> 3809*/ 3810typedef struct sqlite3_stmt sqlite3_stmt; 3811 3812/* 3813** CAPI3REF: Run-time Limits 3814** METHOD: sqlite3 3815** 3816** ^(This interface allows the size of various constructs to be limited 3817** on a connection by connection basis. The first parameter is the 3818** [database connection] whose limit is to be set or queried. The 3819** second parameter is one of the [limit categories] that define a 3820** class of constructs to be size limited. The third parameter is the 3821** new limit for that construct.)^ 3822** 3823** ^If the new limit is a negative number, the limit is unchanged. 3824** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3825** [limits | hard upper bound] 3826** set at compile-time by a C preprocessor macro called 3827** [limits | SQLITE_MAX_<i>NAME</i>]. 3828** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3829** ^Attempts to increase a limit above its hard upper bound are 3830** silently truncated to the hard upper bound. 3831** 3832** ^Regardless of whether or not the limit was changed, the 3833** [sqlite3_limit()] interface returns the prior value of the limit. 3834** ^Hence, to find the current value of a limit without changing it, 3835** simply invoke this interface with the third parameter set to -1. 3836** 3837** Run-time limits are intended for use in applications that manage 3838** both their own internal database and also databases that are controlled 3839** by untrusted external sources. An example application might be a 3840** web browser that has its own databases for storing history and 3841** separate databases controlled by JavaScript applications downloaded 3842** off the Internet. The internal databases can be given the 3843** large, default limits. Databases managed by external sources can 3844** be given much smaller limits designed to prevent a denial of service 3845** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3846** interface to further control untrusted SQL. The size of the database 3847** created by an untrusted script can be contained using the 3848** [max_page_count] [PRAGMA]. 3849** 3850** New run-time limit categories may be added in future releases. 3851*/ 3852SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3853 3854/* 3855** CAPI3REF: Run-Time Limit Categories 3856** KEYWORDS: {limit category} {*limit categories} 3857** 3858** These constants define various performance limits 3859** that can be lowered at run-time using [sqlite3_limit()]. 3860** The synopsis of the meanings of the various limits is shown below. 3861** Additional information is available at [limits | Limits in SQLite]. 3862** 3863** <dl> 3864** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3865** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3866** 3867** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3868** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3869** 3870** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3871** <dd>The maximum number of columns in a table definition or in the 3872** result set of a [SELECT] or the maximum number of columns in an index 3873** or in an ORDER BY or GROUP BY clause.</dd>)^ 3874** 3875** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3876** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3877** 3878** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3879** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3880** 3881** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3882** <dd>The maximum number of instructions in a virtual machine program 3883** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3884** the equivalent tries to allocate space for more than this many opcodes 3885** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3886** 3887** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3888** <dd>The maximum number of arguments on a function.</dd>)^ 3889** 3890** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3891** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3892** 3893** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3894** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3895** <dd>The maximum length of the pattern argument to the [LIKE] or 3896** [GLOB] operators.</dd>)^ 3897** 3898** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3899** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3900** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3901** 3902** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3903** <dd>The maximum depth of recursion for triggers.</dd>)^ 3904** 3905** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3906** <dd>The maximum number of auxiliary worker threads that a single 3907** [prepared statement] may start.</dd>)^ 3908** </dl> 3909*/ 3910#define SQLITE_LIMIT_LENGTH 0 3911#define SQLITE_LIMIT_SQL_LENGTH 1 3912#define SQLITE_LIMIT_COLUMN 2 3913#define SQLITE_LIMIT_EXPR_DEPTH 3 3914#define SQLITE_LIMIT_COMPOUND_SELECT 4 3915#define SQLITE_LIMIT_VDBE_OP 5 3916#define SQLITE_LIMIT_FUNCTION_ARG 6 3917#define SQLITE_LIMIT_ATTACHED 7 3918#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3919#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3920#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3921#define SQLITE_LIMIT_WORKER_THREADS 11 3922 3923/* 3924** CAPI3REF: Prepare Flags 3925** 3926** These constants define various flags that can be passed into 3927** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3928** [sqlite3_prepare16_v3()] interfaces. 3929** 3930** New flags may be added in future releases of SQLite. 3931** 3932** <dl> 3933** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3934** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3935** that the prepared statement will be retained for a long time and 3936** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3937** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3938** be used just once or at most a few times and then destroyed using 3939** [sqlite3_finalize()] relatively soon. The current implementation acts 3940** on this hint by avoiding the use of [lookaside memory] so as not to 3941** deplete the limited store of lookaside memory. Future versions of 3942** SQLite may act on this hint differently. 3943** 3944** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3945** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3946** to be required for any prepared statement that wanted to use the 3947** [sqlite3_normalized_sql()] interface. However, the 3948** [sqlite3_normalized_sql()] interface is now available to all 3949** prepared statements, regardless of whether or not they use this 3950** flag. 3951** 3952** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3953** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3954** to return an error (error code SQLITE_ERROR) if the statement uses 3955** any virtual tables. 3956** </dl> 3957*/ 3958#define SQLITE_PREPARE_PERSISTENT 0x01 3959#define SQLITE_PREPARE_NORMALIZE 0x02 3960#define SQLITE_PREPARE_NO_VTAB 0x04 3961 3962/* 3963** CAPI3REF: Compiling An SQL Statement 3964** KEYWORDS: {SQL statement compiler} 3965** METHOD: sqlite3 3966** CONSTRUCTOR: sqlite3_stmt 3967** 3968** To execute an SQL statement, it must first be compiled into a byte-code 3969** program using one of these routines. Or, in other words, these routines 3970** are constructors for the [prepared statement] object. 3971** 3972** The preferred routine to use is [sqlite3_prepare_v2()]. The 3973** [sqlite3_prepare()] interface is legacy and should be avoided. 3974** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3975** for special purposes. 3976** 3977** The use of the UTF-8 interfaces is preferred, as SQLite currently 3978** does all parsing using UTF-8. The UTF-16 interfaces are provided 3979** as a convenience. The UTF-16 interfaces work by converting the 3980** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3981** 3982** The first argument, "db", is a [database connection] obtained from a 3983** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3984** [sqlite3_open16()]. The database connection must not have been closed. 3985** 3986** The second argument, "zSql", is the statement to be compiled, encoded 3987** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3988** and sqlite3_prepare_v3() 3989** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3990** and sqlite3_prepare16_v3() use UTF-16. 3991** 3992** ^If the nByte argument is negative, then zSql is read up to the 3993** first zero terminator. ^If nByte is positive, then it is the 3994** number of bytes read from zSql. ^If nByte is zero, then no prepared 3995** statement is generated. 3996** If the caller knows that the supplied string is nul-terminated, then 3997** there is a small performance advantage to passing an nByte parameter that 3998** is the number of bytes in the input string <i>including</i> 3999** the nul-terminator. 4000** 4001** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4002** past the end of the first SQL statement in zSql. These routines only 4003** compile the first statement in zSql, so *pzTail is left pointing to 4004** what remains uncompiled. 4005** 4006** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4007** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4008** to NULL. ^If the input text contains no SQL (if the input is an empty 4009** string or a comment) then *ppStmt is set to NULL. 4010** The calling procedure is responsible for deleting the compiled 4011** SQL statement using [sqlite3_finalize()] after it has finished with it. 4012** ppStmt may not be NULL. 4013** 4014** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4015** otherwise an [error code] is returned. 4016** 4017** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4018** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4019** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4020** are retained for backwards compatibility, but their use is discouraged. 4021** ^In the "vX" interfaces, the prepared statement 4022** that is returned (the [sqlite3_stmt] object) contains a copy of the 4023** original SQL text. This causes the [sqlite3_step()] interface to 4024** behave differently in three ways: 4025** 4026** <ol> 4027** <li> 4028** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4029** always used to do, [sqlite3_step()] will automatically recompile the SQL 4030** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4031** retries will occur before sqlite3_step() gives up and returns an error. 4032** </li> 4033** 4034** <li> 4035** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4036** [error codes] or [extended error codes]. ^The legacy behavior was that 4037** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4038** and the application would have to make a second call to [sqlite3_reset()] 4039** in order to find the underlying cause of the problem. With the "v2" prepare 4040** interfaces, the underlying reason for the error is returned immediately. 4041** </li> 4042** 4043** <li> 4044** ^If the specific value bound to a [parameter | host parameter] in the 4045** WHERE clause might influence the choice of query plan for a statement, 4046** then the statement will be automatically recompiled, as if there had been 4047** a schema change, on the first [sqlite3_step()] call following any change 4048** to the [sqlite3_bind_text | bindings] of that [parameter]. 4049** ^The specific value of a WHERE-clause [parameter] might influence the 4050** choice of query plan if the parameter is the left-hand side of a [LIKE] 4051** or [GLOB] operator or if the parameter is compared to an indexed column 4052** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4053** </li> 4054** </ol> 4055** 4056** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4057** the extra prepFlags parameter, which is a bit array consisting of zero or 4058** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4059** sqlite3_prepare_v2() interface works exactly the same as 4060** sqlite3_prepare_v3() with a zero prepFlags parameter. 4061*/ 4062SQLITE_API int sqlite3_prepare( 4063 sqlite3 *db, /* Database handle */ 4064 const char *zSql, /* SQL statement, UTF-8 encoded */ 4065 int nByte, /* Maximum length of zSql in bytes. */ 4066 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4067 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4068); 4069SQLITE_API int sqlite3_prepare_v2( 4070 sqlite3 *db, /* Database handle */ 4071 const char *zSql, /* SQL statement, UTF-8 encoded */ 4072 int nByte, /* Maximum length of zSql in bytes. */ 4073 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4074 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4075); 4076SQLITE_API int sqlite3_prepare_v3( 4077 sqlite3 *db, /* Database handle */ 4078 const char *zSql, /* SQL statement, UTF-8 encoded */ 4079 int nByte, /* Maximum length of zSql in bytes. */ 4080 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4081 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4082 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4083); 4084SQLITE_API int sqlite3_prepare16( 4085 sqlite3 *db, /* Database handle */ 4086 const void *zSql, /* SQL statement, UTF-16 encoded */ 4087 int nByte, /* Maximum length of zSql in bytes. */ 4088 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4089 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4090); 4091SQLITE_API int sqlite3_prepare16_v2( 4092 sqlite3 *db, /* Database handle */ 4093 const void *zSql, /* SQL statement, UTF-16 encoded */ 4094 int nByte, /* Maximum length of zSql in bytes. */ 4095 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4096 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4097); 4098SQLITE_API int sqlite3_prepare16_v3( 4099 sqlite3 *db, /* Database handle */ 4100 const void *zSql, /* SQL statement, UTF-16 encoded */ 4101 int nByte, /* Maximum length of zSql in bytes. */ 4102 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4103 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4104 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4105); 4106 4107/* 4108** CAPI3REF: Retrieving Statement SQL 4109** METHOD: sqlite3_stmt 4110** 4111** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4112** SQL text used to create [prepared statement] P if P was 4113** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4114** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4115** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4116** string containing the SQL text of prepared statement P with 4117** [bound parameters] expanded. 4118** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4119** string containing the normalized SQL text of prepared statement P. The 4120** semantics used to normalize a SQL statement are unspecified and subject 4121** to change. At a minimum, literal values will be replaced with suitable 4122** placeholders. 4123** 4124** ^(For example, if a prepared statement is created using the SQL 4125** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4126** and parameter :xyz is unbound, then sqlite3_sql() will return 4127** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4128** will return "SELECT 2345,NULL".)^ 4129** 4130** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4131** is available to hold the result, or if the result would exceed the 4132** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4133** 4134** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4135** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4136** option causes sqlite3_expanded_sql() to always return NULL. 4137** 4138** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4139** are managed by SQLite and are automatically freed when the prepared 4140** statement is finalized. 4141** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4142** is obtained from [sqlite3_malloc()] and must be free by the application 4143** by passing it to [sqlite3_free()]. 4144*/ 4145SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4146SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4147SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4148 4149/* 4150** CAPI3REF: Determine If An SQL Statement Writes The Database 4151** METHOD: sqlite3_stmt 4152** 4153** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4154** and only if the [prepared statement] X makes no direct changes to 4155** the content of the database file. 4156** 4157** Note that [application-defined SQL functions] or 4158** [virtual tables] might change the database indirectly as a side effect. 4159** ^(For example, if an application defines a function "eval()" that 4160** calls [sqlite3_exec()], then the following SQL statement would 4161** change the database file through side-effects: 4162** 4163** <blockquote><pre> 4164** SELECT eval('DELETE FROM t1') FROM t2; 4165** </pre></blockquote> 4166** 4167** But because the [SELECT] statement does not change the database file 4168** directly, sqlite3_stmt_readonly() would still return true.)^ 4169** 4170** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4171** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4172** since the statements themselves do not actually modify the database but 4173** rather they control the timing of when other statements modify the 4174** database. ^The [ATTACH] and [DETACH] statements also cause 4175** sqlite3_stmt_readonly() to return true since, while those statements 4176** change the configuration of a database connection, they do not make 4177** changes to the content of the database files on disk. 4178** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4179** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4180** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4181** sqlite3_stmt_readonly() returns false for those commands. 4182*/ 4183SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4184 4185/* 4186** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4187** METHOD: sqlite3_stmt 4188** 4189** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4190** prepared statement S is an EXPLAIN statement, or 2 if the 4191** statement S is an EXPLAIN QUERY PLAN. 4192** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4193** an ordinary statement or a NULL pointer. 4194*/ 4195SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4196 4197/* 4198** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4199** METHOD: sqlite3_stmt 4200** 4201** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4202** [prepared statement] S has been stepped at least once using 4203** [sqlite3_step(S)] but has neither run to completion (returned 4204** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4205** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4206** interface returns false if S is a NULL pointer. If S is not a 4207** NULL pointer and is not a pointer to a valid [prepared statement] 4208** object, then the behavior is undefined and probably undesirable. 4209** 4210** This interface can be used in combination [sqlite3_next_stmt()] 4211** to locate all prepared statements associated with a database 4212** connection that are in need of being reset. This can be used, 4213** for example, in diagnostic routines to search for prepared 4214** statements that are holding a transaction open. 4215*/ 4216SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4217 4218/* 4219** CAPI3REF: Dynamically Typed Value Object 4220** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4221** 4222** SQLite uses the sqlite3_value object to represent all values 4223** that can be stored in a database table. SQLite uses dynamic typing 4224** for the values it stores. ^Values stored in sqlite3_value objects 4225** can be integers, floating point values, strings, BLOBs, or NULL. 4226** 4227** An sqlite3_value object may be either "protected" or "unprotected". 4228** Some interfaces require a protected sqlite3_value. Other interfaces 4229** will accept either a protected or an unprotected sqlite3_value. 4230** Every interface that accepts sqlite3_value arguments specifies 4231** whether or not it requires a protected sqlite3_value. The 4232** [sqlite3_value_dup()] interface can be used to construct a new 4233** protected sqlite3_value from an unprotected sqlite3_value. 4234** 4235** The terms "protected" and "unprotected" refer to whether or not 4236** a mutex is held. An internal mutex is held for a protected 4237** sqlite3_value object but no mutex is held for an unprotected 4238** sqlite3_value object. If SQLite is compiled to be single-threaded 4239** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4240** or if SQLite is run in one of reduced mutex modes 4241** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4242** then there is no distinction between protected and unprotected 4243** sqlite3_value objects and they can be used interchangeably. However, 4244** for maximum code portability it is recommended that applications 4245** still make the distinction between protected and unprotected 4246** sqlite3_value objects even when not strictly required. 4247** 4248** ^The sqlite3_value objects that are passed as parameters into the 4249** implementation of [application-defined SQL functions] are protected. 4250** ^The sqlite3_value object returned by 4251** [sqlite3_column_value()] is unprotected. 4252** Unprotected sqlite3_value objects may only be used as arguments 4253** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4254** [sqlite3_value_dup()]. 4255** The [sqlite3_value_blob | sqlite3_value_type()] family of 4256** interfaces require protected sqlite3_value objects. 4257*/ 4258typedef struct sqlite3_value sqlite3_value; 4259 4260/* 4261** CAPI3REF: SQL Function Context Object 4262** 4263** The context in which an SQL function executes is stored in an 4264** sqlite3_context object. ^A pointer to an sqlite3_context object 4265** is always first parameter to [application-defined SQL functions]. 4266** The application-defined SQL function implementation will pass this 4267** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4268** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4269** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4270** and/or [sqlite3_set_auxdata()]. 4271*/ 4272typedef struct sqlite3_context sqlite3_context; 4273 4274/* 4275** CAPI3REF: Binding Values To Prepared Statements 4276** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4277** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4278** METHOD: sqlite3_stmt 4279** 4280** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4281** literals may be replaced by a [parameter] that matches one of following 4282** templates: 4283** 4284** <ul> 4285** <li> ? 4286** <li> ?NNN 4287** <li> :VVV 4288** <li> @VVV 4289** <li> $VVV 4290** </ul> 4291** 4292** In the templates above, NNN represents an integer literal, 4293** and VVV represents an alphanumeric identifier.)^ ^The values of these 4294** parameters (also called "host parameter names" or "SQL parameters") 4295** can be set using the sqlite3_bind_*() routines defined here. 4296** 4297** ^The first argument to the sqlite3_bind_*() routines is always 4298** a pointer to the [sqlite3_stmt] object returned from 4299** [sqlite3_prepare_v2()] or its variants. 4300** 4301** ^The second argument is the index of the SQL parameter to be set. 4302** ^The leftmost SQL parameter has an index of 1. ^When the same named 4303** SQL parameter is used more than once, second and subsequent 4304** occurrences have the same index as the first occurrence. 4305** ^The index for named parameters can be looked up using the 4306** [sqlite3_bind_parameter_index()] API if desired. ^The index 4307** for "?NNN" parameters is the value of NNN. 4308** ^The NNN value must be between 1 and the [sqlite3_limit()] 4309** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4310** 4311** ^The third argument is the value to bind to the parameter. 4312** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4313** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4314** is ignored and the end result is the same as sqlite3_bind_null(). 4315** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4316** it should be a pointer to well-formed UTF8 text. 4317** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4318** it should be a pointer to well-formed UTF16 text. 4319** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4320** it should be a pointer to a well-formed unicode string that is 4321** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4322** otherwise. 4323** 4324** [[byte-order determination rules]] ^The byte-order of 4325** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4326** found in first character, which is removed, or in the absence of a BOM 4327** the byte order is the native byte order of the host 4328** machine for sqlite3_bind_text16() or the byte order specified in 4329** the 6th parameter for sqlite3_bind_text64().)^ 4330** ^If UTF16 input text contains invalid unicode 4331** characters, then SQLite might change those invalid characters 4332** into the unicode replacement character: U+FFFD. 4333** 4334** ^(In those routines that have a fourth argument, its value is the 4335** number of bytes in the parameter. To be clear: the value is the 4336** number of <u>bytes</u> in the value, not the number of characters.)^ 4337** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4338** is negative, then the length of the string is 4339** the number of bytes up to the first zero terminator. 4340** If the fourth parameter to sqlite3_bind_blob() is negative, then 4341** the behavior is undefined. 4342** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4343** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4344** that parameter must be the byte offset 4345** where the NUL terminator would occur assuming the string were NUL 4346** terminated. If any NUL characters occurs at byte offsets less than 4347** the value of the fourth parameter then the resulting string value will 4348** contain embedded NULs. The result of expressions involving strings 4349** with embedded NULs is undefined. 4350** 4351** ^The fifth argument to the BLOB and string binding interfaces 4352** is a destructor used to dispose of the BLOB or 4353** string after SQLite has finished with it. ^The destructor is called 4354** to dispose of the BLOB or string even if the call to the bind API fails, 4355** except the destructor is not called if the third parameter is a NULL 4356** pointer or the fourth parameter is negative. 4357** ^If the fifth argument is 4358** the special value [SQLITE_STATIC], then SQLite assumes that the 4359** information is in static, unmanaged space and does not need to be freed. 4360** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4361** SQLite makes its own private copy of the data immediately, before 4362** the sqlite3_bind_*() routine returns. 4363** 4364** ^The sixth argument to sqlite3_bind_text64() must be one of 4365** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4366** to specify the encoding of the text in the third parameter. If 4367** the sixth argument to sqlite3_bind_text64() is not one of the 4368** allowed values shown above, or if the text encoding is different 4369** from the encoding specified by the sixth parameter, then the behavior 4370** is undefined. 4371** 4372** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4373** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4374** (just an integer to hold its size) while it is being processed. 4375** Zeroblobs are intended to serve as placeholders for BLOBs whose 4376** content is later written using 4377** [sqlite3_blob_open | incremental BLOB I/O] routines. 4378** ^A negative value for the zeroblob results in a zero-length BLOB. 4379** 4380** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4381** [prepared statement] S to have an SQL value of NULL, but to also be 4382** associated with the pointer P of type T. ^D is either a NULL pointer or 4383** a pointer to a destructor function for P. ^SQLite will invoke the 4384** destructor D with a single argument of P when it is finished using 4385** P. The T parameter should be a static string, preferably a string 4386** literal. The sqlite3_bind_pointer() routine is part of the 4387** [pointer passing interface] added for SQLite 3.20.0. 4388** 4389** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4390** for the [prepared statement] or with a prepared statement for which 4391** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4392** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4393** routine is passed a [prepared statement] that has been finalized, the 4394** result is undefined and probably harmful. 4395** 4396** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4397** ^Unbound parameters are interpreted as NULL. 4398** 4399** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4400** [error code] if anything goes wrong. 4401** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4402** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4403** [SQLITE_MAX_LENGTH]. 4404** ^[SQLITE_RANGE] is returned if the parameter 4405** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4406** 4407** See also: [sqlite3_bind_parameter_count()], 4408** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4409*/ 4410SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4411SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4412 void(*)(void*)); 4413SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4414SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4415SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4416SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4417SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4418SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4419SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4420 void(*)(void*), unsigned char encoding); 4421SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4422SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4423SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4424SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4425 4426/* 4427** CAPI3REF: Number Of SQL Parameters 4428** METHOD: sqlite3_stmt 4429** 4430** ^This routine can be used to find the number of [SQL parameters] 4431** in a [prepared statement]. SQL parameters are tokens of the 4432** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4433** placeholders for values that are [sqlite3_bind_blob | bound] 4434** to the parameters at a later time. 4435** 4436** ^(This routine actually returns the index of the largest (rightmost) 4437** parameter. For all forms except ?NNN, this will correspond to the 4438** number of unique parameters. If parameters of the ?NNN form are used, 4439** there may be gaps in the list.)^ 4440** 4441** See also: [sqlite3_bind_blob|sqlite3_bind()], 4442** [sqlite3_bind_parameter_name()], and 4443** [sqlite3_bind_parameter_index()]. 4444*/ 4445SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4446 4447/* 4448** CAPI3REF: Name Of A Host Parameter 4449** METHOD: sqlite3_stmt 4450** 4451** ^The sqlite3_bind_parameter_name(P,N) interface returns 4452** the name of the N-th [SQL parameter] in the [prepared statement] P. 4453** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4454** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4455** respectively. 4456** In other words, the initial ":" or "$" or "@" or "?" 4457** is included as part of the name.)^ 4458** ^Parameters of the form "?" without a following integer have no name 4459** and are referred to as "nameless" or "anonymous parameters". 4460** 4461** ^The first host parameter has an index of 1, not 0. 4462** 4463** ^If the value N is out of range or if the N-th parameter is 4464** nameless, then NULL is returned. ^The returned string is 4465** always in UTF-8 encoding even if the named parameter was 4466** originally specified as UTF-16 in [sqlite3_prepare16()], 4467** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4468** 4469** See also: [sqlite3_bind_blob|sqlite3_bind()], 4470** [sqlite3_bind_parameter_count()], and 4471** [sqlite3_bind_parameter_index()]. 4472*/ 4473SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4474 4475/* 4476** CAPI3REF: Index Of A Parameter With A Given Name 4477** METHOD: sqlite3_stmt 4478** 4479** ^Return the index of an SQL parameter given its name. ^The 4480** index value returned is suitable for use as the second 4481** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4482** is returned if no matching parameter is found. ^The parameter 4483** name must be given in UTF-8 even if the original statement 4484** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4485** [sqlite3_prepare16_v3()]. 4486** 4487** See also: [sqlite3_bind_blob|sqlite3_bind()], 4488** [sqlite3_bind_parameter_count()], and 4489** [sqlite3_bind_parameter_name()]. 4490*/ 4491SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4492 4493/* 4494** CAPI3REF: Reset All Bindings On A Prepared Statement 4495** METHOD: sqlite3_stmt 4496** 4497** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4498** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4499** ^Use this routine to reset all host parameters to NULL. 4500*/ 4501SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4502 4503/* 4504** CAPI3REF: Number Of Columns In A Result Set 4505** METHOD: sqlite3_stmt 4506** 4507** ^Return the number of columns in the result set returned by the 4508** [prepared statement]. ^If this routine returns 0, that means the 4509** [prepared statement] returns no data (for example an [UPDATE]). 4510** ^However, just because this routine returns a positive number does not 4511** mean that one or more rows of data will be returned. ^A SELECT statement 4512** will always have a positive sqlite3_column_count() but depending on the 4513** WHERE clause constraints and the table content, it might return no rows. 4514** 4515** See also: [sqlite3_data_count()] 4516*/ 4517SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4518 4519/* 4520** CAPI3REF: Column Names In A Result Set 4521** METHOD: sqlite3_stmt 4522** 4523** ^These routines return the name assigned to a particular column 4524** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4525** interface returns a pointer to a zero-terminated UTF-8 string 4526** and sqlite3_column_name16() returns a pointer to a zero-terminated 4527** UTF-16 string. ^The first parameter is the [prepared statement] 4528** that implements the [SELECT] statement. ^The second parameter is the 4529** column number. ^The leftmost column is number 0. 4530** 4531** ^The returned string pointer is valid until either the [prepared statement] 4532** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4533** reprepared by the first call to [sqlite3_step()] for a particular run 4534** or until the next call to 4535** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4536** 4537** ^If sqlite3_malloc() fails during the processing of either routine 4538** (for example during a conversion from UTF-8 to UTF-16) then a 4539** NULL pointer is returned. 4540** 4541** ^The name of a result column is the value of the "AS" clause for 4542** that column, if there is an AS clause. If there is no AS clause 4543** then the name of the column is unspecified and may change from 4544** one release of SQLite to the next. 4545*/ 4546SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4547SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4548 4549/* 4550** CAPI3REF: Source Of Data In A Query Result 4551** METHOD: sqlite3_stmt 4552** 4553** ^These routines provide a means to determine the database, table, and 4554** table column that is the origin of a particular result column in 4555** [SELECT] statement. 4556** ^The name of the database or table or column can be returned as 4557** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4558** the database name, the _table_ routines return the table name, and 4559** the origin_ routines return the column name. 4560** ^The returned string is valid until the [prepared statement] is destroyed 4561** using [sqlite3_finalize()] or until the statement is automatically 4562** reprepared by the first call to [sqlite3_step()] for a particular run 4563** or until the same information is requested 4564** again in a different encoding. 4565** 4566** ^The names returned are the original un-aliased names of the 4567** database, table, and column. 4568** 4569** ^The first argument to these interfaces is a [prepared statement]. 4570** ^These functions return information about the Nth result column returned by 4571** the statement, where N is the second function argument. 4572** ^The left-most column is column 0 for these routines. 4573** 4574** ^If the Nth column returned by the statement is an expression or 4575** subquery and is not a column value, then all of these functions return 4576** NULL. ^These routines might also return NULL if a memory allocation error 4577** occurs. ^Otherwise, they return the name of the attached database, table, 4578** or column that query result column was extracted from. 4579** 4580** ^As with all other SQLite APIs, those whose names end with "16" return 4581** UTF-16 encoded strings and the other functions return UTF-8. 4582** 4583** ^These APIs are only available if the library was compiled with the 4584** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4585** 4586** If two or more threads call one or more 4587** [sqlite3_column_database_name | column metadata interfaces] 4588** for the same [prepared statement] and result column 4589** at the same time then the results are undefined. 4590*/ 4591SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4592SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4593SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4594SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4595SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4596SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4597 4598/* 4599** CAPI3REF: Declared Datatype Of A Query Result 4600** METHOD: sqlite3_stmt 4601** 4602** ^(The first parameter is a [prepared statement]. 4603** If this statement is a [SELECT] statement and the Nth column of the 4604** returned result set of that [SELECT] is a table column (not an 4605** expression or subquery) then the declared type of the table 4606** column is returned.)^ ^If the Nth column of the result set is an 4607** expression or subquery, then a NULL pointer is returned. 4608** ^The returned string is always UTF-8 encoded. 4609** 4610** ^(For example, given the database schema: 4611** 4612** CREATE TABLE t1(c1 VARIANT); 4613** 4614** and the following statement to be compiled: 4615** 4616** SELECT c1 + 1, c1 FROM t1; 4617** 4618** this routine would return the string "VARIANT" for the second result 4619** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4620** 4621** ^SQLite uses dynamic run-time typing. ^So just because a column 4622** is declared to contain a particular type does not mean that the 4623** data stored in that column is of the declared type. SQLite is 4624** strongly typed, but the typing is dynamic not static. ^Type 4625** is associated with individual values, not with the containers 4626** used to hold those values. 4627*/ 4628SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4629SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4630 4631/* 4632** CAPI3REF: Evaluate An SQL Statement 4633** METHOD: sqlite3_stmt 4634** 4635** After a [prepared statement] has been prepared using any of 4636** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4637** or [sqlite3_prepare16_v3()] or one of the legacy 4638** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4639** must be called one or more times to evaluate the statement. 4640** 4641** The details of the behavior of the sqlite3_step() interface depend 4642** on whether the statement was prepared using the newer "vX" interfaces 4643** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4644** [sqlite3_prepare16_v2()] or the older legacy 4645** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4646** new "vX" interface is recommended for new applications but the legacy 4647** interface will continue to be supported. 4648** 4649** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4650** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4651** ^With the "v2" interface, any of the other [result codes] or 4652** [extended result codes] might be returned as well. 4653** 4654** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4655** database locks it needs to do its job. ^If the statement is a [COMMIT] 4656** or occurs outside of an explicit transaction, then you can retry the 4657** statement. If the statement is not a [COMMIT] and occurs within an 4658** explicit transaction then you should rollback the transaction before 4659** continuing. 4660** 4661** ^[SQLITE_DONE] means that the statement has finished executing 4662** successfully. sqlite3_step() should not be called again on this virtual 4663** machine without first calling [sqlite3_reset()] to reset the virtual 4664** machine back to its initial state. 4665** 4666** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4667** is returned each time a new row of data is ready for processing by the 4668** caller. The values may be accessed using the [column access functions]. 4669** sqlite3_step() is called again to retrieve the next row of data. 4670** 4671** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4672** violation) has occurred. sqlite3_step() should not be called again on 4673** the VM. More information may be found by calling [sqlite3_errmsg()]. 4674** ^With the legacy interface, a more specific error code (for example, 4675** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4676** can be obtained by calling [sqlite3_reset()] on the 4677** [prepared statement]. ^In the "v2" interface, 4678** the more specific error code is returned directly by sqlite3_step(). 4679** 4680** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4681** Perhaps it was called on a [prepared statement] that has 4682** already been [sqlite3_finalize | finalized] or on one that had 4683** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4684** be the case that the same database connection is being used by two or 4685** more threads at the same moment in time. 4686** 4687** For all versions of SQLite up to and including 3.6.23.1, a call to 4688** [sqlite3_reset()] was required after sqlite3_step() returned anything 4689** other than [SQLITE_ROW] before any subsequent invocation of 4690** sqlite3_step(). Failure to reset the prepared statement using 4691** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4692** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4693** sqlite3_step() began 4694** calling [sqlite3_reset()] automatically in this circumstance rather 4695** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4696** break because any application that ever receives an SQLITE_MISUSE error 4697** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4698** can be used to restore the legacy behavior. 4699** 4700** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4701** API always returns a generic error code, [SQLITE_ERROR], following any 4702** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4703** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4704** specific [error codes] that better describes the error. 4705** We admit that this is a goofy design. The problem has been fixed 4706** with the "v2" interface. If you prepare all of your SQL statements 4707** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4708** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4709** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4710** then the more specific [error codes] are returned directly 4711** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4712*/ 4713SQLITE_API int sqlite3_step(sqlite3_stmt*); 4714 4715/* 4716** CAPI3REF: Number of columns in a result set 4717** METHOD: sqlite3_stmt 4718** 4719** ^The sqlite3_data_count(P) interface returns the number of columns in the 4720** current row of the result set of [prepared statement] P. 4721** ^If prepared statement P does not have results ready to return 4722** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4723** interfaces) then sqlite3_data_count(P) returns 0. 4724** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4725** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4726** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4727** will return non-zero if previous call to [sqlite3_step](P) returned 4728** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4729** where it always returns zero since each step of that multi-step 4730** pragma returns 0 columns of data. 4731** 4732** See also: [sqlite3_column_count()] 4733*/ 4734SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4735 4736/* 4737** CAPI3REF: Fundamental Datatypes 4738** KEYWORDS: SQLITE_TEXT 4739** 4740** ^(Every value in SQLite has one of five fundamental datatypes: 4741** 4742** <ul> 4743** <li> 64-bit signed integer 4744** <li> 64-bit IEEE floating point number 4745** <li> string 4746** <li> BLOB 4747** <li> NULL 4748** </ul>)^ 4749** 4750** These constants are codes for each of those types. 4751** 4752** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4753** for a completely different meaning. Software that links against both 4754** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4755** SQLITE_TEXT. 4756*/ 4757#define SQLITE_INTEGER 1 4758#define SQLITE_FLOAT 2 4759#define SQLITE_BLOB 4 4760#define SQLITE_NULL 5 4761#ifdef SQLITE_TEXT 4762# undef SQLITE_TEXT 4763#else 4764# define SQLITE_TEXT 3 4765#endif 4766#define SQLITE3_TEXT 3 4767 4768/* 4769** CAPI3REF: Result Values From A Query 4770** KEYWORDS: {column access functions} 4771** METHOD: sqlite3_stmt 4772** 4773** <b>Summary:</b> 4774** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4775** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4776** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4777** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4778** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4779** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4780** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4781** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4782** [sqlite3_value|unprotected sqlite3_value] object. 4783** <tr><td> <td> <td> 4784** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4785** or a UTF-8 TEXT result in bytes 4786** <tr><td><b>sqlite3_column_bytes16 </b> 4787** <td>→ <td>Size of UTF-16 4788** TEXT in bytes 4789** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4790** datatype of the result 4791** </table></blockquote> 4792** 4793** <b>Details:</b> 4794** 4795** ^These routines return information about a single column of the current 4796** result row of a query. ^In every case the first argument is a pointer 4797** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4798** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4799** and the second argument is the index of the column for which information 4800** should be returned. ^The leftmost column of the result set has the index 0. 4801** ^The number of columns in the result can be determined using 4802** [sqlite3_column_count()]. 4803** 4804** If the SQL statement does not currently point to a valid row, or if the 4805** column index is out of range, the result is undefined. 4806** These routines may only be called when the most recent call to 4807** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4808** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4809** If any of these routines are called after [sqlite3_reset()] or 4810** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4811** something other than [SQLITE_ROW], the results are undefined. 4812** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4813** are called from a different thread while any of these routines 4814** are pending, then the results are undefined. 4815** 4816** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4817** each return the value of a result column in a specific data format. If 4818** the result column is not initially in the requested format (for example, 4819** if the query returns an integer but the sqlite3_column_text() interface 4820** is used to extract the value) then an automatic type conversion is performed. 4821** 4822** ^The sqlite3_column_type() routine returns the 4823** [SQLITE_INTEGER | datatype code] for the initial data type 4824** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4825** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4826** The return value of sqlite3_column_type() can be used to decide which 4827** of the first six interface should be used to extract the column value. 4828** The value returned by sqlite3_column_type() is only meaningful if no 4829** automatic type conversions have occurred for the value in question. 4830** After a type conversion, the result of calling sqlite3_column_type() 4831** is undefined, though harmless. Future 4832** versions of SQLite may change the behavior of sqlite3_column_type() 4833** following a type conversion. 4834** 4835** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4836** or sqlite3_column_bytes16() interfaces can be used to determine the size 4837** of that BLOB or string. 4838** 4839** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4840** routine returns the number of bytes in that BLOB or string. 4841** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4842** the string to UTF-8 and then returns the number of bytes. 4843** ^If the result is a numeric value then sqlite3_column_bytes() uses 4844** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4845** the number of bytes in that string. 4846** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4847** 4848** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4849** routine returns the number of bytes in that BLOB or string. 4850** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4851** the string to UTF-16 and then returns the number of bytes. 4852** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4853** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4854** the number of bytes in that string. 4855** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4856** 4857** ^The values returned by [sqlite3_column_bytes()] and 4858** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4859** of the string. ^For clarity: the values returned by 4860** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4861** bytes in the string, not the number of characters. 4862** 4863** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4864** even empty strings, are always zero-terminated. ^The return 4865** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4866** 4867** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4868** [unprotected sqlite3_value] object. In a multithreaded environment, 4869** an unprotected sqlite3_value object may only be used safely with 4870** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4871** If the [unprotected sqlite3_value] object returned by 4872** [sqlite3_column_value()] is used in any other way, including calls 4873** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4874** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4875** Hence, the sqlite3_column_value() interface 4876** is normally only useful within the implementation of 4877** [application-defined SQL functions] or [virtual tables], not within 4878** top-level application code. 4879** 4880** The these routines may attempt to convert the datatype of the result. 4881** ^For example, if the internal representation is FLOAT and a text result 4882** is requested, [sqlite3_snprintf()] is used internally to perform the 4883** conversion automatically. ^(The following table details the conversions 4884** that are applied: 4885** 4886** <blockquote> 4887** <table border="1"> 4888** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4889** 4890** <tr><td> NULL <td> INTEGER <td> Result is 0 4891** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4892** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4893** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4894** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4895** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4896** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4897** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4898** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4899** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4900** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4901** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4902** <tr><td> TEXT <td> BLOB <td> No change 4903** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4904** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4905** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4906** </table> 4907** </blockquote>)^ 4908** 4909** Note that when type conversions occur, pointers returned by prior 4910** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4911** sqlite3_column_text16() may be invalidated. 4912** Type conversions and pointer invalidations might occur 4913** in the following cases: 4914** 4915** <ul> 4916** <li> The initial content is a BLOB and sqlite3_column_text() or 4917** sqlite3_column_text16() is called. A zero-terminator might 4918** need to be added to the string.</li> 4919** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4920** sqlite3_column_text16() is called. The content must be converted 4921** to UTF-16.</li> 4922** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4923** sqlite3_column_text() is called. The content must be converted 4924** to UTF-8.</li> 4925** </ul> 4926** 4927** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4928** not invalidate a prior pointer, though of course the content of the buffer 4929** that the prior pointer references will have been modified. Other kinds 4930** of conversion are done in place when it is possible, but sometimes they 4931** are not possible and in those cases prior pointers are invalidated. 4932** 4933** The safest policy is to invoke these routines 4934** in one of the following ways: 4935** 4936** <ul> 4937** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4938** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4939** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4940** </ul> 4941** 4942** In other words, you should call sqlite3_column_text(), 4943** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4944** into the desired format, then invoke sqlite3_column_bytes() or 4945** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4946** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4947** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4948** with calls to sqlite3_column_bytes(). 4949** 4950** ^The pointers returned are valid until a type conversion occurs as 4951** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4952** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4953** and BLOBs is freed automatically. Do not pass the pointers returned 4954** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4955** [sqlite3_free()]. 4956** 4957** As long as the input parameters are correct, these routines will only 4958** fail if an out-of-memory error occurs during a format conversion. 4959** Only the following subset of interfaces are subject to out-of-memory 4960** errors: 4961** 4962** <ul> 4963** <li> sqlite3_column_blob() 4964** <li> sqlite3_column_text() 4965** <li> sqlite3_column_text16() 4966** <li> sqlite3_column_bytes() 4967** <li> sqlite3_column_bytes16() 4968** </ul> 4969** 4970** If an out-of-memory error occurs, then the return value from these 4971** routines is the same as if the column had contained an SQL NULL value. 4972** Valid SQL NULL returns can be distinguished from out-of-memory errors 4973** by invoking the [sqlite3_errcode()] immediately after the suspect 4974** return value is obtained and before any 4975** other SQLite interface is called on the same [database connection]. 4976*/ 4977SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4978SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4979SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4980SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4981SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4982SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4983SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4984SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4985SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4986SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4987 4988/* 4989** CAPI3REF: Destroy A Prepared Statement Object 4990** DESTRUCTOR: sqlite3_stmt 4991** 4992** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4993** ^If the most recent evaluation of the statement encountered no errors 4994** or if the statement is never been evaluated, then sqlite3_finalize() returns 4995** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4996** sqlite3_finalize(S) returns the appropriate [error code] or 4997** [extended error code]. 4998** 4999** ^The sqlite3_finalize(S) routine can be called at any point during 5000** the life cycle of [prepared statement] S: 5001** before statement S is ever evaluated, after 5002** one or more calls to [sqlite3_reset()], or after any call 5003** to [sqlite3_step()] regardless of whether or not the statement has 5004** completed execution. 5005** 5006** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5007** 5008** The application must finalize every [prepared statement] in order to avoid 5009** resource leaks. It is a grievous error for the application to try to use 5010** a prepared statement after it has been finalized. Any use of a prepared 5011** statement after it has been finalized can result in undefined and 5012** undesirable behavior such as segfaults and heap corruption. 5013*/ 5014SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5015 5016/* 5017** CAPI3REF: Reset A Prepared Statement Object 5018** METHOD: sqlite3_stmt 5019** 5020** The sqlite3_reset() function is called to reset a [prepared statement] 5021** object back to its initial state, ready to be re-executed. 5022** ^Any SQL statement variables that had values bound to them using 5023** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5024** Use [sqlite3_clear_bindings()] to reset the bindings. 5025** 5026** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5027** back to the beginning of its program. 5028** 5029** ^If the most recent call to [sqlite3_step(S)] for the 5030** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5031** or if [sqlite3_step(S)] has never before been called on S, 5032** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5033** 5034** ^If the most recent call to [sqlite3_step(S)] for the 5035** [prepared statement] S indicated an error, then 5036** [sqlite3_reset(S)] returns an appropriate [error code]. 5037** 5038** ^The [sqlite3_reset(S)] interface does not change the values 5039** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5040*/ 5041SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5042 5043/* 5044** CAPI3REF: Create Or Redefine SQL Functions 5045** KEYWORDS: {function creation routines} 5046** METHOD: sqlite3 5047** 5048** ^These functions (collectively known as "function creation routines") 5049** are used to add SQL functions or aggregates or to redefine the behavior 5050** of existing SQL functions or aggregates. The only differences between 5051** the three "sqlite3_create_function*" routines are the text encoding 5052** expected for the second parameter (the name of the function being 5053** created) and the presence or absence of a destructor callback for 5054** the application data pointer. Function sqlite3_create_window_function() 5055** is similar, but allows the user to supply the extra callback functions 5056** needed by [aggregate window functions]. 5057** 5058** ^The first parameter is the [database connection] to which the SQL 5059** function is to be added. ^If an application uses more than one database 5060** connection then application-defined SQL functions must be added 5061** to each database connection separately. 5062** 5063** ^The second parameter is the name of the SQL function to be created or 5064** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5065** representation, exclusive of the zero-terminator. ^Note that the name 5066** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5067** ^Any attempt to create a function with a longer name 5068** will result in [SQLITE_MISUSE] being returned. 5069** 5070** ^The third parameter (nArg) 5071** is the number of arguments that the SQL function or 5072** aggregate takes. ^If this parameter is -1, then the SQL function or 5073** aggregate may take any number of arguments between 0 and the limit 5074** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5075** parameter is less than -1 or greater than 127 then the behavior is 5076** undefined. 5077** 5078** ^The fourth parameter, eTextRep, specifies what 5079** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5080** its parameters. The application should set this parameter to 5081** [SQLITE_UTF16LE] if the function implementation invokes 5082** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5083** implementation invokes [sqlite3_value_text16be()] on an input, or 5084** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5085** otherwise. ^The same SQL function may be registered multiple times using 5086** different preferred text encodings, with different implementations for 5087** each encoding. 5088** ^When multiple implementations of the same function are available, SQLite 5089** will pick the one that involves the least amount of data conversion. 5090** 5091** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5092** to signal that the function will always return the same result given 5093** the same inputs within a single SQL statement. Most SQL functions are 5094** deterministic. The built-in [random()] SQL function is an example of a 5095** function that is not deterministic. The SQLite query planner is able to 5096** perform additional optimizations on deterministic functions, so use 5097** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5098** 5099** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5100** flag, which if present prevents the function from being invoked from 5101** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5102** index expressions, or the WHERE clause of partial indexes. 5103** 5104** <span style="background-color:#ffff90;"> 5105** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5106** all application-defined SQL functions that do not need to be 5107** used inside of triggers, view, CHECK constraints, or other elements of 5108** the database schema. This flags is especially recommended for SQL 5109** functions that have side effects or reveal internal application state. 5110** Without this flag, an attacker might be able to modify the schema of 5111** a database file to include invocations of the function with parameters 5112** chosen by the attacker, which the application will then execute when 5113** the database file is opened and read. 5114** </span> 5115** 5116** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5117** function can gain access to this pointer using [sqlite3_user_data()].)^ 5118** 5119** ^The sixth, seventh and eighth parameters passed to the three 5120** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5121** pointers to C-language functions that implement the SQL function or 5122** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5123** callback only; NULL pointers must be passed as the xStep and xFinal 5124** parameters. ^An aggregate SQL function requires an implementation of xStep 5125** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5126** SQL function or aggregate, pass NULL pointers for all three function 5127** callbacks. 5128** 5129** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5130** and xInverse) passed to sqlite3_create_window_function are pointers to 5131** C-language callbacks that implement the new function. xStep and xFinal 5132** must both be non-NULL. xValue and xInverse may either both be NULL, in 5133** which case a regular aggregate function is created, or must both be 5134** non-NULL, in which case the new function may be used as either an aggregate 5135** or aggregate window function. More details regarding the implementation 5136** of aggregate window functions are 5137** [user-defined window functions|available here]. 5138** 5139** ^(If the final parameter to sqlite3_create_function_v2() or 5140** sqlite3_create_window_function() is not NULL, then it is destructor for 5141** the application data pointer. The destructor is invoked when the function 5142** is deleted, either by being overloaded or when the database connection 5143** closes.)^ ^The destructor is also invoked if the call to 5144** sqlite3_create_function_v2() fails. ^When the destructor callback is 5145** invoked, it is passed a single argument which is a copy of the application 5146** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5147** 5148** ^It is permitted to register multiple implementations of the same 5149** functions with the same name but with either differing numbers of 5150** arguments or differing preferred text encodings. ^SQLite will use 5151** the implementation that most closely matches the way in which the 5152** SQL function is used. ^A function implementation with a non-negative 5153** nArg parameter is a better match than a function implementation with 5154** a negative nArg. ^A function where the preferred text encoding 5155** matches the database encoding is a better 5156** match than a function where the encoding is different. 5157** ^A function where the encoding difference is between UTF16le and UTF16be 5158** is a closer match than a function where the encoding difference is 5159** between UTF8 and UTF16. 5160** 5161** ^Built-in functions may be overloaded by new application-defined functions. 5162** 5163** ^An application-defined function is permitted to call other 5164** SQLite interfaces. However, such calls must not 5165** close the database connection nor finalize or reset the prepared 5166** statement in which the function is running. 5167*/ 5168SQLITE_API int sqlite3_create_function( 5169 sqlite3 *db, 5170 const char *zFunctionName, 5171 int nArg, 5172 int eTextRep, 5173 void *pApp, 5174 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5175 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5176 void (*xFinal)(sqlite3_context*) 5177); 5178SQLITE_API int sqlite3_create_function16( 5179 sqlite3 *db, 5180 const void *zFunctionName, 5181 int nArg, 5182 int eTextRep, 5183 void *pApp, 5184 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5185 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5186 void (*xFinal)(sqlite3_context*) 5187); 5188SQLITE_API int sqlite3_create_function_v2( 5189 sqlite3 *db, 5190 const char *zFunctionName, 5191 int nArg, 5192 int eTextRep, 5193 void *pApp, 5194 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5195 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5196 void (*xFinal)(sqlite3_context*), 5197 void(*xDestroy)(void*) 5198); 5199SQLITE_API int sqlite3_create_window_function( 5200 sqlite3 *db, 5201 const char *zFunctionName, 5202 int nArg, 5203 int eTextRep, 5204 void *pApp, 5205 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5206 void (*xFinal)(sqlite3_context*), 5207 void (*xValue)(sqlite3_context*), 5208 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5209 void(*xDestroy)(void*) 5210); 5211 5212/* 5213** CAPI3REF: Text Encodings 5214** 5215** These constant define integer codes that represent the various 5216** text encodings supported by SQLite. 5217*/ 5218#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5219#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5220#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5221#define SQLITE_UTF16 4 /* Use native byte order */ 5222#define SQLITE_ANY 5 /* Deprecated */ 5223#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5224 5225/* 5226** CAPI3REF: Function Flags 5227** 5228** These constants may be ORed together with the 5229** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5230** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5231** [sqlite3_create_function_v2()]. 5232** 5233** <dl> 5234** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5235** The SQLITE_DETERMINISTIC flag means that the new function always gives 5236** the same output when the input parameters are the same. 5237** The [abs|abs() function] is deterministic, for example, but 5238** [randomblob|randomblob()] is not. Functions must 5239** be deterministic in order to be used in certain contexts such as 5240** with the WHERE clause of [partial indexes] or in [generated columns]. 5241** SQLite might also optimize deterministic functions by factoring them 5242** out of inner loops. 5243** </dd> 5244** 5245** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5246** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5247** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5248** schema structures such as [CHECK constraints], [DEFAULT clauses], 5249** [expression indexes], [partial indexes], or [generated columns]. 5250** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5251** for all [application-defined SQL functions], and especially for functions 5252** that have side-effects or that could potentially leak sensitive 5253** information. 5254** </dd> 5255** 5256** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5257** The SQLITE_INNOCUOUS flag means that the function is unlikely 5258** to cause problems even if misused. An innocuous function should have 5259** no side effects and should not depend on any values other than its 5260** input parameters. The [abs|abs() function] is an example of an 5261** innocuous function. 5262** The [load_extension() SQL function] is not innocuous because of its 5263** side effects. 5264** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5265** exactly the same. The [random|random() function] is an example of a 5266** function that is innocuous but not deterministic. 5267** <p>Some heightened security settings 5268** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5269** disable the use of SQL functions inside views and triggers and in 5270** schema structures such as [CHECK constraints], [DEFAULT clauses], 5271** [expression indexes], [partial indexes], and [generated columns] unless 5272** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5273** are innocuous. Developers are advised to avoid using the 5274** SQLITE_INNOCUOUS flag for application-defined functions unless the 5275** function has been carefully audited and found to be free of potentially 5276** security-adverse side-effects and information-leaks. 5277** </dd> 5278** 5279** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5280** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5281** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5282** Specifying this flag makes no difference for scalar or aggregate user 5283** functions. However, if it is not specified for a user-defined window 5284** function, then any sub-types belonging to arguments passed to the window 5285** function may be discarded before the window function is called (i.e. 5286** sqlite3_value_subtype() will always return 0). 5287** </dd> 5288** </dl> 5289*/ 5290#define SQLITE_DETERMINISTIC 0x000000800 5291#define SQLITE_DIRECTONLY 0x000080000 5292#define SQLITE_SUBTYPE 0x000100000 5293#define SQLITE_INNOCUOUS 0x000200000 5294 5295/* 5296** CAPI3REF: Deprecated Functions 5297** DEPRECATED 5298** 5299** These functions are [deprecated]. In order to maintain 5300** backwards compatibility with older code, these functions continue 5301** to be supported. However, new applications should avoid 5302** the use of these functions. To encourage programmers to avoid 5303** these functions, we will not explain what they do. 5304*/ 5305#ifndef SQLITE_OMIT_DEPRECATED 5306SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5307SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5308SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5309SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5310SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5311SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5312 void*,sqlite3_int64); 5313#endif 5314 5315/* 5316** CAPI3REF: Obtaining SQL Values 5317** METHOD: sqlite3_value 5318** 5319** <b>Summary:</b> 5320** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5321** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5322** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5323** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5324** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5325** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5326** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5327** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5328** the native byteorder 5329** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5330** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5331** <tr><td> <td> <td> 5332** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5333** or a UTF-8 TEXT in bytes 5334** <tr><td><b>sqlite3_value_bytes16 </b> 5335** <td>→ <td>Size of UTF-16 5336** TEXT in bytes 5337** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5338** datatype of the value 5339** <tr><td><b>sqlite3_value_numeric_type </b> 5340** <td>→ <td>Best numeric datatype of the value 5341** <tr><td><b>sqlite3_value_nochange </b> 5342** <td>→ <td>True if the column is unchanged in an UPDATE 5343** against a virtual table. 5344** <tr><td><b>sqlite3_value_frombind </b> 5345** <td>→ <td>True if value originated from a [bound parameter] 5346** </table></blockquote> 5347** 5348** <b>Details:</b> 5349** 5350** These routines extract type, size, and content information from 5351** [protected sqlite3_value] objects. Protected sqlite3_value objects 5352** are used to pass parameter information into the functions that 5353** implement [application-defined SQL functions] and [virtual tables]. 5354** 5355** These routines work only with [protected sqlite3_value] objects. 5356** Any attempt to use these routines on an [unprotected sqlite3_value] 5357** is not threadsafe. 5358** 5359** ^These routines work just like the corresponding [column access functions] 5360** except that these routines take a single [protected sqlite3_value] object 5361** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5362** 5363** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5364** in the native byte-order of the host machine. ^The 5365** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5366** extract UTF-16 strings as big-endian and little-endian respectively. 5367** 5368** ^If [sqlite3_value] object V was initialized 5369** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5370** and if X and Y are strings that compare equal according to strcmp(X,Y), 5371** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5372** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5373** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5374** 5375** ^(The sqlite3_value_type(V) interface returns the 5376** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5377** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5378** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5379** Other interfaces might change the datatype for an sqlite3_value object. 5380** For example, if the datatype is initially SQLITE_INTEGER and 5381** sqlite3_value_text(V) is called to extract a text value for that 5382** integer, then subsequent calls to sqlite3_value_type(V) might return 5383** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5384** occurs is undefined and may change from one release of SQLite to the next. 5385** 5386** ^(The sqlite3_value_numeric_type() interface attempts to apply 5387** numeric affinity to the value. This means that an attempt is 5388** made to convert the value to an integer or floating point. If 5389** such a conversion is possible without loss of information (in other 5390** words, if the value is a string that looks like a number) 5391** then the conversion is performed. Otherwise no conversion occurs. 5392** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5393** 5394** ^Within the [xUpdate] method of a [virtual table], the 5395** sqlite3_value_nochange(X) interface returns true if and only if 5396** the column corresponding to X is unchanged by the UPDATE operation 5397** that the xUpdate method call was invoked to implement and if 5398** and the prior [xColumn] method call that was invoked to extracted 5399** the value for that column returned without setting a result (probably 5400** because it queried [sqlite3_vtab_nochange()] and found that the column 5401** was unchanging). ^Within an [xUpdate] method, any value for which 5402** sqlite3_value_nochange(X) is true will in all other respects appear 5403** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5404** than within an [xUpdate] method call for an UPDATE statement, then 5405** the return value is arbitrary and meaningless. 5406** 5407** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5408** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5409** interfaces. ^If X comes from an SQL literal value, or a table column, 5410** or an expression, then sqlite3_value_frombind(X) returns zero. 5411** 5412** Please pay particular attention to the fact that the pointer returned 5413** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5414** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5415** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5416** or [sqlite3_value_text16()]. 5417** 5418** These routines must be called from the same thread as 5419** the SQL function that supplied the [sqlite3_value*] parameters. 5420** 5421** As long as the input parameter is correct, these routines can only 5422** fail if an out-of-memory error occurs during a format conversion. 5423** Only the following subset of interfaces are subject to out-of-memory 5424** errors: 5425** 5426** <ul> 5427** <li> sqlite3_value_blob() 5428** <li> sqlite3_value_text() 5429** <li> sqlite3_value_text16() 5430** <li> sqlite3_value_text16le() 5431** <li> sqlite3_value_text16be() 5432** <li> sqlite3_value_bytes() 5433** <li> sqlite3_value_bytes16() 5434** </ul> 5435** 5436** If an out-of-memory error occurs, then the return value from these 5437** routines is the same as if the column had contained an SQL NULL value. 5438** Valid SQL NULL returns can be distinguished from out-of-memory errors 5439** by invoking the [sqlite3_errcode()] immediately after the suspect 5440** return value is obtained and before any 5441** other SQLite interface is called on the same [database connection]. 5442*/ 5443SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5444SQLITE_API double sqlite3_value_double(sqlite3_value*); 5445SQLITE_API int sqlite3_value_int(sqlite3_value*); 5446SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5447SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5448SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5449SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5450SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5451SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5452SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5453SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5454SQLITE_API int sqlite3_value_type(sqlite3_value*); 5455SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5456SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5457SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5458 5459/* 5460** CAPI3REF: Finding The Subtype Of SQL Values 5461** METHOD: sqlite3_value 5462** 5463** The sqlite3_value_subtype(V) function returns the subtype for 5464** an [application-defined SQL function] argument V. The subtype 5465** information can be used to pass a limited amount of context from 5466** one SQL function to another. Use the [sqlite3_result_subtype()] 5467** routine to set the subtype for the return value of an SQL function. 5468*/ 5469SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5470 5471/* 5472** CAPI3REF: Copy And Free SQL Values 5473** METHOD: sqlite3_value 5474** 5475** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5476** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5477** is a [protected sqlite3_value] object even if the input is not. 5478** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5479** memory allocation fails. 5480** 5481** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5482** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5483** then sqlite3_value_free(V) is a harmless no-op. 5484*/ 5485SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5486SQLITE_API void sqlite3_value_free(sqlite3_value*); 5487 5488/* 5489** CAPI3REF: Obtain Aggregate Function Context 5490** METHOD: sqlite3_context 5491** 5492** Implementations of aggregate SQL functions use this 5493** routine to allocate memory for storing their state. 5494** 5495** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5496** for a particular aggregate function, SQLite allocates 5497** N bytes of memory, zeroes out that memory, and returns a pointer 5498** to the new memory. ^On second and subsequent calls to 5499** sqlite3_aggregate_context() for the same aggregate function instance, 5500** the same buffer is returned. Sqlite3_aggregate_context() is normally 5501** called once for each invocation of the xStep callback and then one 5502** last time when the xFinal callback is invoked. ^(When no rows match 5503** an aggregate query, the xStep() callback of the aggregate function 5504** implementation is never called and xFinal() is called exactly once. 5505** In those cases, sqlite3_aggregate_context() might be called for the 5506** first time from within xFinal().)^ 5507** 5508** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5509** when first called if N is less than or equal to zero or if a memory 5510** allocate error occurs. 5511** 5512** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5513** determined by the N parameter on first successful call. Changing the 5514** value of N in any subsequent call to sqlite3_aggregate_context() within 5515** the same aggregate function instance will not resize the memory 5516** allocation.)^ Within the xFinal callback, it is customary to set 5517** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5518** pointless memory allocations occur. 5519** 5520** ^SQLite automatically frees the memory allocated by 5521** sqlite3_aggregate_context() when the aggregate query concludes. 5522** 5523** The first parameter must be a copy of the 5524** [sqlite3_context | SQL function context] that is the first parameter 5525** to the xStep or xFinal callback routine that implements the aggregate 5526** function. 5527** 5528** This routine must be called from the same thread in which 5529** the aggregate SQL function is running. 5530*/ 5531SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5532 5533/* 5534** CAPI3REF: User Data For Functions 5535** METHOD: sqlite3_context 5536** 5537** ^The sqlite3_user_data() interface returns a copy of 5538** the pointer that was the pUserData parameter (the 5th parameter) 5539** of the [sqlite3_create_function()] 5540** and [sqlite3_create_function16()] routines that originally 5541** registered the application defined function. 5542** 5543** This routine must be called from the same thread in which 5544** the application-defined function is running. 5545*/ 5546SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5547 5548/* 5549** CAPI3REF: Database Connection For Functions 5550** METHOD: sqlite3_context 5551** 5552** ^The sqlite3_context_db_handle() interface returns a copy of 5553** the pointer to the [database connection] (the 1st parameter) 5554** of the [sqlite3_create_function()] 5555** and [sqlite3_create_function16()] routines that originally 5556** registered the application defined function. 5557*/ 5558SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5559 5560/* 5561** CAPI3REF: Function Auxiliary Data 5562** METHOD: sqlite3_context 5563** 5564** These functions may be used by (non-aggregate) SQL functions to 5565** associate metadata with argument values. If the same value is passed to 5566** multiple invocations of the same SQL function during query execution, under 5567** some circumstances the associated metadata may be preserved. An example 5568** of where this might be useful is in a regular-expression matching 5569** function. The compiled version of the regular expression can be stored as 5570** metadata associated with the pattern string. 5571** Then as long as the pattern string remains the same, 5572** the compiled regular expression can be reused on multiple 5573** invocations of the same function. 5574** 5575** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5576** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5577** value to the application-defined function. ^N is zero for the left-most 5578** function argument. ^If there is no metadata 5579** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5580** returns a NULL pointer. 5581** 5582** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5583** argument of the application-defined function. ^Subsequent 5584** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5585** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5586** NULL if the metadata has been discarded. 5587** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5588** SQLite will invoke the destructor function X with parameter P exactly 5589** once, when the metadata is discarded. 5590** SQLite is free to discard the metadata at any time, including: <ul> 5591** <li> ^(when the corresponding function parameter changes)^, or 5592** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5593** SQL statement)^, or 5594** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5595** parameter)^, or 5596** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5597** allocation error occurs.)^ </ul> 5598** 5599** Note the last bullet in particular. The destructor X in 5600** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5601** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5602** should be called near the end of the function implementation and the 5603** function implementation should not make any use of P after 5604** sqlite3_set_auxdata() has been called. 5605** 5606** ^(In practice, metadata is preserved between function calls for 5607** function parameters that are compile-time constants, including literal 5608** values and [parameters] and expressions composed from the same.)^ 5609** 5610** The value of the N parameter to these interfaces should be non-negative. 5611** Future enhancements may make use of negative N values to define new 5612** kinds of function caching behavior. 5613** 5614** These routines must be called from the same thread in which 5615** the SQL function is running. 5616*/ 5617SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5618SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5619 5620 5621/* 5622** CAPI3REF: Constants Defining Special Destructor Behavior 5623** 5624** These are special values for the destructor that is passed in as the 5625** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5626** argument is SQLITE_STATIC, it means that the content pointer is constant 5627** and will never change. It does not need to be destroyed. ^The 5628** SQLITE_TRANSIENT value means that the content will likely change in 5629** the near future and that SQLite should make its own private copy of 5630** the content before returning. 5631** 5632** The typedef is necessary to work around problems in certain 5633** C++ compilers. 5634*/ 5635typedef void (*sqlite3_destructor_type)(void*); 5636#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5637#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5638 5639/* 5640** CAPI3REF: Setting The Result Of An SQL Function 5641** METHOD: sqlite3_context 5642** 5643** These routines are used by the xFunc or xFinal callbacks that 5644** implement SQL functions and aggregates. See 5645** [sqlite3_create_function()] and [sqlite3_create_function16()] 5646** for additional information. 5647** 5648** These functions work very much like the [parameter binding] family of 5649** functions used to bind values to host parameters in prepared statements. 5650** Refer to the [SQL parameter] documentation for additional information. 5651** 5652** ^The sqlite3_result_blob() interface sets the result from 5653** an application-defined function to be the BLOB whose content is pointed 5654** to by the second parameter and which is N bytes long where N is the 5655** third parameter. 5656** 5657** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5658** interfaces set the result of the application-defined function to be 5659** a BLOB containing all zero bytes and N bytes in size. 5660** 5661** ^The sqlite3_result_double() interface sets the result from 5662** an application-defined function to be a floating point value specified 5663** by its 2nd argument. 5664** 5665** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5666** cause the implemented SQL function to throw an exception. 5667** ^SQLite uses the string pointed to by the 5668** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5669** as the text of an error message. ^SQLite interprets the error 5670** message string from sqlite3_result_error() as UTF-8. ^SQLite 5671** interprets the string from sqlite3_result_error16() as UTF-16 using 5672** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5673** ^If the third parameter to sqlite3_result_error() 5674** or sqlite3_result_error16() is negative then SQLite takes as the error 5675** message all text up through the first zero character. 5676** ^If the third parameter to sqlite3_result_error() or 5677** sqlite3_result_error16() is non-negative then SQLite takes that many 5678** bytes (not characters) from the 2nd parameter as the error message. 5679** ^The sqlite3_result_error() and sqlite3_result_error16() 5680** routines make a private copy of the error message text before 5681** they return. Hence, the calling function can deallocate or 5682** modify the text after they return without harm. 5683** ^The sqlite3_result_error_code() function changes the error code 5684** returned by SQLite as a result of an error in a function. ^By default, 5685** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5686** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5687** 5688** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5689** error indicating that a string or BLOB is too long to represent. 5690** 5691** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5692** error indicating that a memory allocation failed. 5693** 5694** ^The sqlite3_result_int() interface sets the return value 5695** of the application-defined function to be the 32-bit signed integer 5696** value given in the 2nd argument. 5697** ^The sqlite3_result_int64() interface sets the return value 5698** of the application-defined function to be the 64-bit signed integer 5699** value given in the 2nd argument. 5700** 5701** ^The sqlite3_result_null() interface sets the return value 5702** of the application-defined function to be NULL. 5703** 5704** ^The sqlite3_result_text(), sqlite3_result_text16(), 5705** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5706** set the return value of the application-defined function to be 5707** a text string which is represented as UTF-8, UTF-16 native byte order, 5708** UTF-16 little endian, or UTF-16 big endian, respectively. 5709** ^The sqlite3_result_text64() interface sets the return value of an 5710** application-defined function to be a text string in an encoding 5711** specified by the fifth (and last) parameter, which must be one 5712** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5713** ^SQLite takes the text result from the application from 5714** the 2nd parameter of the sqlite3_result_text* interfaces. 5715** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5716** is negative, then SQLite takes result text from the 2nd parameter 5717** through the first zero character. 5718** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5719** is non-negative, then as many bytes (not characters) of the text 5720** pointed to by the 2nd parameter are taken as the application-defined 5721** function result. If the 3rd parameter is non-negative, then it 5722** must be the byte offset into the string where the NUL terminator would 5723** appear if the string where NUL terminated. If any NUL characters occur 5724** in the string at a byte offset that is less than the value of the 3rd 5725** parameter, then the resulting string will contain embedded NULs and the 5726** result of expressions operating on strings with embedded NULs is undefined. 5727** ^If the 4th parameter to the sqlite3_result_text* interfaces 5728** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5729** function as the destructor on the text or BLOB result when it has 5730** finished using that result. 5731** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5732** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5733** assumes that the text or BLOB result is in constant space and does not 5734** copy the content of the parameter nor call a destructor on the content 5735** when it has finished using that result. 5736** ^If the 4th parameter to the sqlite3_result_text* interfaces 5737** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5738** then SQLite makes a copy of the result into space obtained 5739** from [sqlite3_malloc()] before it returns. 5740** 5741** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5742** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5743** when the encoding is not UTF8, if the input UTF16 begins with a 5744** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5745** string and the rest of the string is interpreted according to the 5746** byte-order specified by the BOM. ^The byte-order specified by 5747** the BOM at the beginning of the text overrides the byte-order 5748** specified by the interface procedure. ^So, for example, if 5749** sqlite3_result_text16le() is invoked with text that begins 5750** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5751** first two bytes of input are skipped and the remaining input 5752** is interpreted as UTF16BE text. 5753** 5754** ^For UTF16 input text to the sqlite3_result_text16(), 5755** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5756** sqlite3_result_text64() routines, if the text contains invalid 5757** UTF16 characters, the invalid characters might be converted 5758** into the unicode replacement character, U+FFFD. 5759** 5760** ^The sqlite3_result_value() interface sets the result of 5761** the application-defined function to be a copy of the 5762** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5763** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5764** so that the [sqlite3_value] specified in the parameter may change or 5765** be deallocated after sqlite3_result_value() returns without harm. 5766** ^A [protected sqlite3_value] object may always be used where an 5767** [unprotected sqlite3_value] object is required, so either 5768** kind of [sqlite3_value] object can be used with this interface. 5769** 5770** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5771** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5772** also associates the host-language pointer P or type T with that 5773** NULL value such that the pointer can be retrieved within an 5774** [application-defined SQL function] using [sqlite3_value_pointer()]. 5775** ^If the D parameter is not NULL, then it is a pointer to a destructor 5776** for the P parameter. ^SQLite invokes D with P as its only argument 5777** when SQLite is finished with P. The T parameter should be a static 5778** string and preferably a string literal. The sqlite3_result_pointer() 5779** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5780** 5781** If these routines are called from within the different thread 5782** than the one containing the application-defined function that received 5783** the [sqlite3_context] pointer, the results are undefined. 5784*/ 5785SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5786SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5787 sqlite3_uint64,void(*)(void*)); 5788SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5789SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5790SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5791SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5792SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5793SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5794SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5795SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5796SQLITE_API void sqlite3_result_null(sqlite3_context*); 5797SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5798SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5799 void(*)(void*), unsigned char encoding); 5800SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5801SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5802SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5803SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5804SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5805SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5806SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5807 5808 5809/* 5810** CAPI3REF: Setting The Subtype Of An SQL Function 5811** METHOD: sqlite3_context 5812** 5813** The sqlite3_result_subtype(C,T) function causes the subtype of 5814** the result from the [application-defined SQL function] with 5815** [sqlite3_context] C to be the value T. Only the lower 8 bits 5816** of the subtype T are preserved in current versions of SQLite; 5817** higher order bits are discarded. 5818** The number of subtype bytes preserved by SQLite might increase 5819** in future releases of SQLite. 5820*/ 5821SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5822 5823/* 5824** CAPI3REF: Define New Collating Sequences 5825** METHOD: sqlite3 5826** 5827** ^These functions add, remove, or modify a [collation] associated 5828** with the [database connection] specified as the first argument. 5829** 5830** ^The name of the collation is a UTF-8 string 5831** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5832** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5833** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5834** considered to be the same name. 5835** 5836** ^(The third argument (eTextRep) must be one of the constants: 5837** <ul> 5838** <li> [SQLITE_UTF8], 5839** <li> [SQLITE_UTF16LE], 5840** <li> [SQLITE_UTF16BE], 5841** <li> [SQLITE_UTF16], or 5842** <li> [SQLITE_UTF16_ALIGNED]. 5843** </ul>)^ 5844** ^The eTextRep argument determines the encoding of strings passed 5845** to the collating function callback, xCompare. 5846** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5847** force strings to be UTF16 with native byte order. 5848** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5849** on an even byte address. 5850** 5851** ^The fourth argument, pArg, is an application data pointer that is passed 5852** through as the first argument to the collating function callback. 5853** 5854** ^The fifth argument, xCompare, is a pointer to the collating function. 5855** ^Multiple collating functions can be registered using the same name but 5856** with different eTextRep parameters and SQLite will use whichever 5857** function requires the least amount of data transformation. 5858** ^If the xCompare argument is NULL then the collating function is 5859** deleted. ^When all collating functions having the same name are deleted, 5860** that collation is no longer usable. 5861** 5862** ^The collating function callback is invoked with a copy of the pArg 5863** application data pointer and with two strings in the encoding specified 5864** by the eTextRep argument. The two integer parameters to the collating 5865** function callback are the length of the two strings, in bytes. The collating 5866** function must return an integer that is negative, zero, or positive 5867** if the first string is less than, equal to, or greater than the second, 5868** respectively. A collating function must always return the same answer 5869** given the same inputs. If two or more collating functions are registered 5870** to the same collation name (using different eTextRep values) then all 5871** must give an equivalent answer when invoked with equivalent strings. 5872** The collating function must obey the following properties for all 5873** strings A, B, and C: 5874** 5875** <ol> 5876** <li> If A==B then B==A. 5877** <li> If A==B and B==C then A==C. 5878** <li> If A<B THEN B>A. 5879** <li> If A<B and B<C then A<C. 5880** </ol> 5881** 5882** If a collating function fails any of the above constraints and that 5883** collating function is registered and used, then the behavior of SQLite 5884** is undefined. 5885** 5886** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5887** with the addition that the xDestroy callback is invoked on pArg when 5888** the collating function is deleted. 5889** ^Collating functions are deleted when they are overridden by later 5890** calls to the collation creation functions or when the 5891** [database connection] is closed using [sqlite3_close()]. 5892** 5893** ^The xDestroy callback is <u>not</u> called if the 5894** sqlite3_create_collation_v2() function fails. Applications that invoke 5895** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5896** check the return code and dispose of the application data pointer 5897** themselves rather than expecting SQLite to deal with it for them. 5898** This is different from every other SQLite interface. The inconsistency 5899** is unfortunate but cannot be changed without breaking backwards 5900** compatibility. 5901** 5902** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5903*/ 5904SQLITE_API int sqlite3_create_collation( 5905 sqlite3*, 5906 const char *zName, 5907 int eTextRep, 5908 void *pArg, 5909 int(*xCompare)(void*,int,const void*,int,const void*) 5910); 5911SQLITE_API int sqlite3_create_collation_v2( 5912 sqlite3*, 5913 const char *zName, 5914 int eTextRep, 5915 void *pArg, 5916 int(*xCompare)(void*,int,const void*,int,const void*), 5917 void(*xDestroy)(void*) 5918); 5919SQLITE_API int sqlite3_create_collation16( 5920 sqlite3*, 5921 const void *zName, 5922 int eTextRep, 5923 void *pArg, 5924 int(*xCompare)(void*,int,const void*,int,const void*) 5925); 5926 5927/* 5928** CAPI3REF: Collation Needed Callbacks 5929** METHOD: sqlite3 5930** 5931** ^To avoid having to register all collation sequences before a database 5932** can be used, a single callback function may be registered with the 5933** [database connection] to be invoked whenever an undefined collation 5934** sequence is required. 5935** 5936** ^If the function is registered using the sqlite3_collation_needed() API, 5937** then it is passed the names of undefined collation sequences as strings 5938** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5939** the names are passed as UTF-16 in machine native byte order. 5940** ^A call to either function replaces the existing collation-needed callback. 5941** 5942** ^(When the callback is invoked, the first argument passed is a copy 5943** of the second argument to sqlite3_collation_needed() or 5944** sqlite3_collation_needed16(). The second argument is the database 5945** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5946** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5947** sequence function required. The fourth parameter is the name of the 5948** required collation sequence.)^ 5949** 5950** The callback function should register the desired collation using 5951** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5952** [sqlite3_create_collation_v2()]. 5953*/ 5954SQLITE_API int sqlite3_collation_needed( 5955 sqlite3*, 5956 void*, 5957 void(*)(void*,sqlite3*,int eTextRep,const char*) 5958); 5959SQLITE_API int sqlite3_collation_needed16( 5960 sqlite3*, 5961 void*, 5962 void(*)(void*,sqlite3*,int eTextRep,const void*) 5963); 5964 5965#ifdef SQLITE_ENABLE_CEROD 5966/* 5967** Specify the activation key for a CEROD database. Unless 5968** activated, none of the CEROD routines will work. 5969*/ 5970SQLITE_API void sqlite3_activate_cerod( 5971 const char *zPassPhrase /* Activation phrase */ 5972); 5973#endif 5974 5975/* 5976** CAPI3REF: Suspend Execution For A Short Time 5977** 5978** The sqlite3_sleep() function causes the current thread to suspend execution 5979** for at least a number of milliseconds specified in its parameter. 5980** 5981** If the operating system does not support sleep requests with 5982** millisecond time resolution, then the time will be rounded up to 5983** the nearest second. The number of milliseconds of sleep actually 5984** requested from the operating system is returned. 5985** 5986** ^SQLite implements this interface by calling the xSleep() 5987** method of the default [sqlite3_vfs] object. If the xSleep() method 5988** of the default VFS is not implemented correctly, or not implemented at 5989** all, then the behavior of sqlite3_sleep() may deviate from the description 5990** in the previous paragraphs. 5991*/ 5992SQLITE_API int sqlite3_sleep(int); 5993 5994/* 5995** CAPI3REF: Name Of The Folder Holding Temporary Files 5996** 5997** ^(If this global variable is made to point to a string which is 5998** the name of a folder (a.k.a. directory), then all temporary files 5999** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6000** will be placed in that directory.)^ ^If this variable 6001** is a NULL pointer, then SQLite performs a search for an appropriate 6002** temporary file directory. 6003** 6004** Applications are strongly discouraged from using this global variable. 6005** It is required to set a temporary folder on Windows Runtime (WinRT). 6006** But for all other platforms, it is highly recommended that applications 6007** neither read nor write this variable. This global variable is a relic 6008** that exists for backwards compatibility of legacy applications and should 6009** be avoided in new projects. 6010** 6011** It is not safe to read or modify this variable in more than one 6012** thread at a time. It is not safe to read or modify this variable 6013** if a [database connection] is being used at the same time in a separate 6014** thread. 6015** It is intended that this variable be set once 6016** as part of process initialization and before any SQLite interface 6017** routines have been called and that this variable remain unchanged 6018** thereafter. 6019** 6020** ^The [temp_store_directory pragma] may modify this variable and cause 6021** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6022** the [temp_store_directory pragma] always assumes that any string 6023** that this variable points to is held in memory obtained from 6024** [sqlite3_malloc] and the pragma may attempt to free that memory 6025** using [sqlite3_free]. 6026** Hence, if this variable is modified directly, either it should be 6027** made NULL or made to point to memory obtained from [sqlite3_malloc] 6028** or else the use of the [temp_store_directory pragma] should be avoided. 6029** Except when requested by the [temp_store_directory pragma], SQLite 6030** does not free the memory that sqlite3_temp_directory points to. If 6031** the application wants that memory to be freed, it must do 6032** so itself, taking care to only do so after all [database connection] 6033** objects have been destroyed. 6034** 6035** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6036** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6037** features that require the use of temporary files may fail. Here is an 6038** example of how to do this using C++ with the Windows Runtime: 6039** 6040** <blockquote><pre> 6041** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6042** TemporaryFolder->Path->Data(); 6043** char zPathBuf[MAX_PATH + 1]; 6044** memset(zPathBuf, 0, sizeof(zPathBuf)); 6045** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6046** NULL, NULL); 6047** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6048** </pre></blockquote> 6049*/ 6050SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6051 6052/* 6053** CAPI3REF: Name Of The Folder Holding Database Files 6054** 6055** ^(If this global variable is made to point to a string which is 6056** the name of a folder (a.k.a. directory), then all database files 6057** specified with a relative pathname and created or accessed by 6058** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6059** to be relative to that directory.)^ ^If this variable is a NULL 6060** pointer, then SQLite assumes that all database files specified 6061** with a relative pathname are relative to the current directory 6062** for the process. Only the windows VFS makes use of this global 6063** variable; it is ignored by the unix VFS. 6064** 6065** Changing the value of this variable while a database connection is 6066** open can result in a corrupt database. 6067** 6068** It is not safe to read or modify this variable in more than one 6069** thread at a time. It is not safe to read or modify this variable 6070** if a [database connection] is being used at the same time in a separate 6071** thread. 6072** It is intended that this variable be set once 6073** as part of process initialization and before any SQLite interface 6074** routines have been called and that this variable remain unchanged 6075** thereafter. 6076** 6077** ^The [data_store_directory pragma] may modify this variable and cause 6078** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6079** the [data_store_directory pragma] always assumes that any string 6080** that this variable points to is held in memory obtained from 6081** [sqlite3_malloc] and the pragma may attempt to free that memory 6082** using [sqlite3_free]. 6083** Hence, if this variable is modified directly, either it should be 6084** made NULL or made to point to memory obtained from [sqlite3_malloc] 6085** or else the use of the [data_store_directory pragma] should be avoided. 6086*/ 6087SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6088 6089/* 6090** CAPI3REF: Win32 Specific Interface 6091** 6092** These interfaces are available only on Windows. The 6093** [sqlite3_win32_set_directory] interface is used to set the value associated 6094** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6095** zValue, depending on the value of the type parameter. The zValue parameter 6096** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6097** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6098** prior to being used. The [sqlite3_win32_set_directory] interface returns 6099** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6100** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6101** [sqlite3_data_directory] variable is intended to act as a replacement for 6102** the current directory on the sub-platforms of Win32 where that concept is 6103** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6104** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6105** sqlite3_win32_set_directory interface except the string parameter must be 6106** UTF-8 or UTF-16, respectively. 6107*/ 6108SQLITE_API int sqlite3_win32_set_directory( 6109 unsigned long type, /* Identifier for directory being set or reset */ 6110 void *zValue /* New value for directory being set or reset */ 6111); 6112SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6113SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6114 6115/* 6116** CAPI3REF: Win32 Directory Types 6117** 6118** These macros are only available on Windows. They define the allowed values 6119** for the type argument to the [sqlite3_win32_set_directory] interface. 6120*/ 6121#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6122#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6123 6124/* 6125** CAPI3REF: Test For Auto-Commit Mode 6126** KEYWORDS: {autocommit mode} 6127** METHOD: sqlite3 6128** 6129** ^The sqlite3_get_autocommit() interface returns non-zero or 6130** zero if the given database connection is or is not in autocommit mode, 6131** respectively. ^Autocommit mode is on by default. 6132** ^Autocommit mode is disabled by a [BEGIN] statement. 6133** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6134** 6135** If certain kinds of errors occur on a statement within a multi-statement 6136** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6137** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6138** transaction might be rolled back automatically. The only way to 6139** find out whether SQLite automatically rolled back the transaction after 6140** an error is to use this function. 6141** 6142** If another thread changes the autocommit status of the database 6143** connection while this routine is running, then the return value 6144** is undefined. 6145*/ 6146SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6147 6148/* 6149** CAPI3REF: Find The Database Handle Of A Prepared Statement 6150** METHOD: sqlite3_stmt 6151** 6152** ^The sqlite3_db_handle interface returns the [database connection] handle 6153** to which a [prepared statement] belongs. ^The [database connection] 6154** returned by sqlite3_db_handle is the same [database connection] 6155** that was the first argument 6156** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6157** create the statement in the first place. 6158*/ 6159SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6160 6161/* 6162** CAPI3REF: Return The Filename For A Database Connection 6163** METHOD: sqlite3 6164** 6165** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6166** associated with database N of connection D. 6167** ^If there is no attached database N on the database 6168** connection D, or if database N is a temporary or in-memory database, then 6169** this function will return either a NULL pointer or an empty string. 6170** 6171** ^The string value returned by this routine is owned and managed by 6172** the database connection. ^The value will be valid until the database N 6173** is [DETACH]-ed or until the database connection closes. 6174** 6175** ^The filename returned by this function is the output of the 6176** xFullPathname method of the [VFS]. ^In other words, the filename 6177** will be an absolute pathname, even if the filename used 6178** to open the database originally was a URI or relative pathname. 6179** 6180** If the filename pointer returned by this routine is not NULL, then it 6181** can be used as the filename input parameter to these routines: 6182** <ul> 6183** <li> [sqlite3_uri_parameter()] 6184** <li> [sqlite3_uri_boolean()] 6185** <li> [sqlite3_uri_int64()] 6186** <li> [sqlite3_filename_database()] 6187** <li> [sqlite3_filename_journal()] 6188** <li> [sqlite3_filename_wal()] 6189** </ul> 6190*/ 6191SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6192 6193/* 6194** CAPI3REF: Determine if a database is read-only 6195** METHOD: sqlite3 6196** 6197** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6198** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6199** the name of a database on connection D. 6200*/ 6201SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6202 6203/* 6204** CAPI3REF: Determine the transaction state of a database 6205** METHOD: sqlite3 6206** 6207** ^The sqlite3_txn_state(D,S) interface returns the current 6208** [transaction state] of schema S in database connection D. ^If S is NULL, 6209** then the highest transaction state of any schema on database connection D 6210** is returned. Transaction states are (in order of lowest to highest): 6211** <ol> 6212** <li value="0"> SQLITE_TXN_NONE 6213** <li value="1"> SQLITE_TXN_READ 6214** <li value="2"> SQLITE_TXN_WRITE 6215** </ol> 6216** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6217** a valid schema, then -1 is returned. 6218*/ 6219SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6220 6221/* 6222** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6223** KEYWORDS: {transaction state} 6224** 6225** These constants define the current transaction state of a database file. 6226** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6227** constants in order to describe the transaction state of schema S 6228** in [database connection] D. 6229** 6230** <dl> 6231** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6232** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6233** pending.</dd> 6234** 6235** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6236** <dd>The SQLITE_TXN_READ state means that the database is currently 6237** in a read transaction. Content has been read from the database file 6238** but nothing in the database file has changed. The transaction state 6239** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6240** no other conflicting concurrent write transactions. The transaction 6241** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6242** [COMMIT].</dd> 6243** 6244** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6245** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6246** in a write transaction. Content has been written to the database file 6247** but has not yet committed. The transaction state will change to 6248** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6249*/ 6250#define SQLITE_TXN_NONE 0 6251#define SQLITE_TXN_READ 1 6252#define SQLITE_TXN_WRITE 2 6253 6254/* 6255** CAPI3REF: Find the next prepared statement 6256** METHOD: sqlite3 6257** 6258** ^This interface returns a pointer to the next [prepared statement] after 6259** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6260** then this interface returns a pointer to the first prepared statement 6261** associated with the database connection pDb. ^If no prepared statement 6262** satisfies the conditions of this routine, it returns NULL. 6263** 6264** The [database connection] pointer D in a call to 6265** [sqlite3_next_stmt(D,S)] must refer to an open database 6266** connection and in particular must not be a NULL pointer. 6267*/ 6268SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6269 6270/* 6271** CAPI3REF: Commit And Rollback Notification Callbacks 6272** METHOD: sqlite3 6273** 6274** ^The sqlite3_commit_hook() interface registers a callback 6275** function to be invoked whenever a transaction is [COMMIT | committed]. 6276** ^Any callback set by a previous call to sqlite3_commit_hook() 6277** for the same database connection is overridden. 6278** ^The sqlite3_rollback_hook() interface registers a callback 6279** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6280** ^Any callback set by a previous call to sqlite3_rollback_hook() 6281** for the same database connection is overridden. 6282** ^The pArg argument is passed through to the callback. 6283** ^If the callback on a commit hook function returns non-zero, 6284** then the commit is converted into a rollback. 6285** 6286** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6287** return the P argument from the previous call of the same function 6288** on the same [database connection] D, or NULL for 6289** the first call for each function on D. 6290** 6291** The commit and rollback hook callbacks are not reentrant. 6292** The callback implementation must not do anything that will modify 6293** the database connection that invoked the callback. Any actions 6294** to modify the database connection must be deferred until after the 6295** completion of the [sqlite3_step()] call that triggered the commit 6296** or rollback hook in the first place. 6297** Note that running any other SQL statements, including SELECT statements, 6298** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6299** the database connections for the meaning of "modify" in this paragraph. 6300** 6301** ^Registering a NULL function disables the callback. 6302** 6303** ^When the commit hook callback routine returns zero, the [COMMIT] 6304** operation is allowed to continue normally. ^If the commit hook 6305** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6306** ^The rollback hook is invoked on a rollback that results from a commit 6307** hook returning non-zero, just as it would be with any other rollback. 6308** 6309** ^For the purposes of this API, a transaction is said to have been 6310** rolled back if an explicit "ROLLBACK" statement is executed, or 6311** an error or constraint causes an implicit rollback to occur. 6312** ^The rollback callback is not invoked if a transaction is 6313** automatically rolled back because the database connection is closed. 6314** 6315** See also the [sqlite3_update_hook()] interface. 6316*/ 6317SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6318SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6319 6320/* 6321** CAPI3REF: Data Change Notification Callbacks 6322** METHOD: sqlite3 6323** 6324** ^The sqlite3_update_hook() interface registers a callback function 6325** with the [database connection] identified by the first argument 6326** to be invoked whenever a row is updated, inserted or deleted in 6327** a [rowid table]. 6328** ^Any callback set by a previous call to this function 6329** for the same database connection is overridden. 6330** 6331** ^The second argument is a pointer to the function to invoke when a 6332** row is updated, inserted or deleted in a rowid table. 6333** ^The first argument to the callback is a copy of the third argument 6334** to sqlite3_update_hook(). 6335** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6336** or [SQLITE_UPDATE], depending on the operation that caused the callback 6337** to be invoked. 6338** ^The third and fourth arguments to the callback contain pointers to the 6339** database and table name containing the affected row. 6340** ^The final callback parameter is the [rowid] of the row. 6341** ^In the case of an update, this is the [rowid] after the update takes place. 6342** 6343** ^(The update hook is not invoked when internal system tables are 6344** modified (i.e. sqlite_sequence).)^ 6345** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6346** 6347** ^In the current implementation, the update hook 6348** is not invoked when conflicting rows are deleted because of an 6349** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6350** invoked when rows are deleted using the [truncate optimization]. 6351** The exceptions defined in this paragraph might change in a future 6352** release of SQLite. 6353** 6354** The update hook implementation must not do anything that will modify 6355** the database connection that invoked the update hook. Any actions 6356** to modify the database connection must be deferred until after the 6357** completion of the [sqlite3_step()] call that triggered the update hook. 6358** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6359** database connections for the meaning of "modify" in this paragraph. 6360** 6361** ^The sqlite3_update_hook(D,C,P) function 6362** returns the P argument from the previous call 6363** on the same [database connection] D, or NULL for 6364** the first call on D. 6365** 6366** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6367** and [sqlite3_preupdate_hook()] interfaces. 6368*/ 6369SQLITE_API void *sqlite3_update_hook( 6370 sqlite3*, 6371 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6372 void* 6373); 6374 6375/* 6376** CAPI3REF: Enable Or Disable Shared Pager Cache 6377** 6378** ^(This routine enables or disables the sharing of the database cache 6379** and schema data structures between [database connection | connections] 6380** to the same database. Sharing is enabled if the argument is true 6381** and disabled if the argument is false.)^ 6382** 6383** ^Cache sharing is enabled and disabled for an entire process. 6384** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6385** In prior versions of SQLite, 6386** sharing was enabled or disabled for each thread separately. 6387** 6388** ^(The cache sharing mode set by this interface effects all subsequent 6389** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6390** Existing database connections continue to use the sharing mode 6391** that was in effect at the time they were opened.)^ 6392** 6393** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6394** successfully. An [error code] is returned otherwise.)^ 6395** 6396** ^Shared cache is disabled by default. It is recommended that it stay 6397** that way. In other words, do not use this routine. This interface 6398** continues to be provided for historical compatibility, but its use is 6399** discouraged. Any use of shared cache is discouraged. If shared cache 6400** must be used, it is recommended that shared cache only be enabled for 6401** individual database connections using the [sqlite3_open_v2()] interface 6402** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6403** 6404** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6405** and will always return SQLITE_MISUSE. On those systems, 6406** shared cache mode should be enabled per-database connection via 6407** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6408** 6409** This interface is threadsafe on processors where writing a 6410** 32-bit integer is atomic. 6411** 6412** See Also: [SQLite Shared-Cache Mode] 6413*/ 6414SQLITE_API int sqlite3_enable_shared_cache(int); 6415 6416/* 6417** CAPI3REF: Attempt To Free Heap Memory 6418** 6419** ^The sqlite3_release_memory() interface attempts to free N bytes 6420** of heap memory by deallocating non-essential memory allocations 6421** held by the database library. Memory used to cache database 6422** pages to improve performance is an example of non-essential memory. 6423** ^sqlite3_release_memory() returns the number of bytes actually freed, 6424** which might be more or less than the amount requested. 6425** ^The sqlite3_release_memory() routine is a no-op returning zero 6426** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6427** 6428** See also: [sqlite3_db_release_memory()] 6429*/ 6430SQLITE_API int sqlite3_release_memory(int); 6431 6432/* 6433** CAPI3REF: Free Memory Used By A Database Connection 6434** METHOD: sqlite3 6435** 6436** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6437** memory as possible from database connection D. Unlike the 6438** [sqlite3_release_memory()] interface, this interface is in effect even 6439** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6440** omitted. 6441** 6442** See also: [sqlite3_release_memory()] 6443*/ 6444SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6445 6446/* 6447** CAPI3REF: Impose A Limit On Heap Size 6448** 6449** These interfaces impose limits on the amount of heap memory that will be 6450** by all database connections within a single process. 6451** 6452** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6453** soft limit on the amount of heap memory that may be allocated by SQLite. 6454** ^SQLite strives to keep heap memory utilization below the soft heap 6455** limit by reducing the number of pages held in the page cache 6456** as heap memory usages approaches the limit. 6457** ^The soft heap limit is "soft" because even though SQLite strives to stay 6458** below the limit, it will exceed the limit rather than generate 6459** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6460** is advisory only. 6461** 6462** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6463** N bytes on the amount of memory that will be allocated. ^The 6464** sqlite3_hard_heap_limit64(N) interface is similar to 6465** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6466** when the hard heap limit is reached. 6467** 6468** ^The return value from both sqlite3_soft_heap_limit64() and 6469** sqlite3_hard_heap_limit64() is the size of 6470** the heap limit prior to the call, or negative in the case of an 6471** error. ^If the argument N is negative 6472** then no change is made to the heap limit. Hence, the current 6473** size of heap limits can be determined by invoking 6474** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6475** 6476** ^Setting the heap limits to zero disables the heap limiter mechanism. 6477** 6478** ^The soft heap limit may not be greater than the hard heap limit. 6479** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6480** is invoked with a value of N that is greater than the hard heap limit, 6481** the the soft heap limit is set to the value of the hard heap limit. 6482** ^The soft heap limit is automatically enabled whenever the hard heap 6483** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6484** the soft heap limit is outside the range of 1..N, then the soft heap 6485** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6486** hard heap limit is enabled makes the soft heap limit equal to the 6487** hard heap limit. 6488** 6489** The memory allocation limits can also be adjusted using 6490** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6491** 6492** ^(The heap limits are not enforced in the current implementation 6493** if one or more of following conditions are true: 6494** 6495** <ul> 6496** <li> The limit value is set to zero. 6497** <li> Memory accounting is disabled using a combination of the 6498** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6499** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6500** <li> An alternative page cache implementation is specified using 6501** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6502** <li> The page cache allocates from its own memory pool supplied 6503** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6504** from the heap. 6505** </ul>)^ 6506** 6507** The circumstances under which SQLite will enforce the heap limits may 6508** changes in future releases of SQLite. 6509*/ 6510SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6511SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6512 6513/* 6514** CAPI3REF: Deprecated Soft Heap Limit Interface 6515** DEPRECATED 6516** 6517** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6518** interface. This routine is provided for historical compatibility 6519** only. All new applications should use the 6520** [sqlite3_soft_heap_limit64()] interface rather than this one. 6521*/ 6522SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6523 6524 6525/* 6526** CAPI3REF: Extract Metadata About A Column Of A Table 6527** METHOD: sqlite3 6528** 6529** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6530** information about column C of table T in database D 6531** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6532** interface returns SQLITE_OK and fills in the non-NULL pointers in 6533** the final five arguments with appropriate values if the specified 6534** column exists. ^The sqlite3_table_column_metadata() interface returns 6535** SQLITE_ERROR if the specified column does not exist. 6536** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6537** NULL pointer, then this routine simply checks for the existence of the 6538** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6539** does not. If the table name parameter T in a call to 6540** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6541** undefined behavior. 6542** 6543** ^The column is identified by the second, third and fourth parameters to 6544** this function. ^(The second parameter is either the name of the database 6545** (i.e. "main", "temp", or an attached database) containing the specified 6546** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6547** for the table using the same algorithm used by the database engine to 6548** resolve unqualified table references. 6549** 6550** ^The third and fourth parameters to this function are the table and column 6551** name of the desired column, respectively. 6552** 6553** ^Metadata is returned by writing to the memory locations passed as the 5th 6554** and subsequent parameters to this function. ^Any of these arguments may be 6555** NULL, in which case the corresponding element of metadata is omitted. 6556** 6557** ^(<blockquote> 6558** <table border="1"> 6559** <tr><th> Parameter <th> Output<br>Type <th> Description 6560** 6561** <tr><td> 5th <td> const char* <td> Data type 6562** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6563** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6564** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6565** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6566** </table> 6567** </blockquote>)^ 6568** 6569** ^The memory pointed to by the character pointers returned for the 6570** declaration type and collation sequence is valid until the next 6571** call to any SQLite API function. 6572** 6573** ^If the specified table is actually a view, an [error code] is returned. 6574** 6575** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6576** is not a [WITHOUT ROWID] table and an 6577** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6578** parameters are set for the explicitly declared column. ^(If there is no 6579** [INTEGER PRIMARY KEY] column, then the outputs 6580** for the [rowid] are set as follows: 6581** 6582** <pre> 6583** data type: "INTEGER" 6584** collation sequence: "BINARY" 6585** not null: 0 6586** primary key: 1 6587** auto increment: 0 6588** </pre>)^ 6589** 6590** ^This function causes all database schemas to be read from disk and 6591** parsed, if that has not already been done, and returns an error if 6592** any errors are encountered while loading the schema. 6593*/ 6594SQLITE_API int sqlite3_table_column_metadata( 6595 sqlite3 *db, /* Connection handle */ 6596 const char *zDbName, /* Database name or NULL */ 6597 const char *zTableName, /* Table name */ 6598 const char *zColumnName, /* Column name */ 6599 char const **pzDataType, /* OUTPUT: Declared data type */ 6600 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6601 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6602 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6603 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6604); 6605 6606/* 6607** CAPI3REF: Load An Extension 6608** METHOD: sqlite3 6609** 6610** ^This interface loads an SQLite extension library from the named file. 6611** 6612** ^The sqlite3_load_extension() interface attempts to load an 6613** [SQLite extension] library contained in the file zFile. If 6614** the file cannot be loaded directly, attempts are made to load 6615** with various operating-system specific extensions added. 6616** So for example, if "samplelib" cannot be loaded, then names like 6617** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6618** be tried also. 6619** 6620** ^The entry point is zProc. 6621** ^(zProc may be 0, in which case SQLite will try to come up with an 6622** entry point name on its own. It first tries "sqlite3_extension_init". 6623** If that does not work, it constructs a name "sqlite3_X_init" where the 6624** X is consists of the lower-case equivalent of all ASCII alphabetic 6625** characters in the filename from the last "/" to the first following 6626** "." and omitting any initial "lib".)^ 6627** ^The sqlite3_load_extension() interface returns 6628** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6629** ^If an error occurs and pzErrMsg is not 0, then the 6630** [sqlite3_load_extension()] interface shall attempt to 6631** fill *pzErrMsg with error message text stored in memory 6632** obtained from [sqlite3_malloc()]. The calling function 6633** should free this memory by calling [sqlite3_free()]. 6634** 6635** ^Extension loading must be enabled using 6636** [sqlite3_enable_load_extension()] or 6637** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6638** prior to calling this API, 6639** otherwise an error will be returned. 6640** 6641** <b>Security warning:</b> It is recommended that the 6642** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6643** interface. The use of the [sqlite3_enable_load_extension()] interface 6644** should be avoided. This will keep the SQL function [load_extension()] 6645** disabled and prevent SQL injections from giving attackers 6646** access to extension loading capabilities. 6647** 6648** See also the [load_extension() SQL function]. 6649*/ 6650SQLITE_API int sqlite3_load_extension( 6651 sqlite3 *db, /* Load the extension into this database connection */ 6652 const char *zFile, /* Name of the shared library containing extension */ 6653 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6654 char **pzErrMsg /* Put error message here if not 0 */ 6655); 6656 6657/* 6658** CAPI3REF: Enable Or Disable Extension Loading 6659** METHOD: sqlite3 6660** 6661** ^So as not to open security holes in older applications that are 6662** unprepared to deal with [extension loading], and as a means of disabling 6663** [extension loading] while evaluating user-entered SQL, the following API 6664** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6665** 6666** ^Extension loading is off by default. 6667** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6668** to turn extension loading on and call it with onoff==0 to turn 6669** it back off again. 6670** 6671** ^This interface enables or disables both the C-API 6672** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6673** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6674** to enable or disable only the C-API.)^ 6675** 6676** <b>Security warning:</b> It is recommended that extension loading 6677** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6678** rather than this interface, so the [load_extension()] SQL function 6679** remains disabled. This will prevent SQL injections from giving attackers 6680** access to extension loading capabilities. 6681*/ 6682SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6683 6684/* 6685** CAPI3REF: Automatically Load Statically Linked Extensions 6686** 6687** ^This interface causes the xEntryPoint() function to be invoked for 6688** each new [database connection] that is created. The idea here is that 6689** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6690** that is to be automatically loaded into all new database connections. 6691** 6692** ^(Even though the function prototype shows that xEntryPoint() takes 6693** no arguments and returns void, SQLite invokes xEntryPoint() with three 6694** arguments and expects an integer result as if the signature of the 6695** entry point where as follows: 6696** 6697** <blockquote><pre> 6698** int xEntryPoint( 6699** sqlite3 *db, 6700** const char **pzErrMsg, 6701** const struct sqlite3_api_routines *pThunk 6702** ); 6703** </pre></blockquote>)^ 6704** 6705** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6706** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6707** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6708** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6709** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6710** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6711** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6712** 6713** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6714** on the list of automatic extensions is a harmless no-op. ^No entry point 6715** will be called more than once for each database connection that is opened. 6716** 6717** See also: [sqlite3_reset_auto_extension()] 6718** and [sqlite3_cancel_auto_extension()] 6719*/ 6720SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6721 6722/* 6723** CAPI3REF: Cancel Automatic Extension Loading 6724** 6725** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6726** initialization routine X that was registered using a prior call to 6727** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6728** routine returns 1 if initialization routine X was successfully 6729** unregistered and it returns 0 if X was not on the list of initialization 6730** routines. 6731*/ 6732SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6733 6734/* 6735** CAPI3REF: Reset Automatic Extension Loading 6736** 6737** ^This interface disables all automatic extensions previously 6738** registered using [sqlite3_auto_extension()]. 6739*/ 6740SQLITE_API void sqlite3_reset_auto_extension(void); 6741 6742/* 6743** The interface to the virtual-table mechanism is currently considered 6744** to be experimental. The interface might change in incompatible ways. 6745** If this is a problem for you, do not use the interface at this time. 6746** 6747** When the virtual-table mechanism stabilizes, we will declare the 6748** interface fixed, support it indefinitely, and remove this comment. 6749*/ 6750 6751/* 6752** Structures used by the virtual table interface 6753*/ 6754typedef struct sqlite3_vtab sqlite3_vtab; 6755typedef struct sqlite3_index_info sqlite3_index_info; 6756typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6757typedef struct sqlite3_module sqlite3_module; 6758 6759/* 6760** CAPI3REF: Virtual Table Object 6761** KEYWORDS: sqlite3_module {virtual table module} 6762** 6763** This structure, sometimes called a "virtual table module", 6764** defines the implementation of a [virtual table]. 6765** This structure consists mostly of methods for the module. 6766** 6767** ^A virtual table module is created by filling in a persistent 6768** instance of this structure and passing a pointer to that instance 6769** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6770** ^The registration remains valid until it is replaced by a different 6771** module or until the [database connection] closes. The content 6772** of this structure must not change while it is registered with 6773** any database connection. 6774*/ 6775struct sqlite3_module { 6776 int iVersion; 6777 int (*xCreate)(sqlite3*, void *pAux, 6778 int argc, const char *const*argv, 6779 sqlite3_vtab **ppVTab, char**); 6780 int (*xConnect)(sqlite3*, void *pAux, 6781 int argc, const char *const*argv, 6782 sqlite3_vtab **ppVTab, char**); 6783 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6784 int (*xDisconnect)(sqlite3_vtab *pVTab); 6785 int (*xDestroy)(sqlite3_vtab *pVTab); 6786 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6787 int (*xClose)(sqlite3_vtab_cursor*); 6788 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6789 int argc, sqlite3_value **argv); 6790 int (*xNext)(sqlite3_vtab_cursor*); 6791 int (*xEof)(sqlite3_vtab_cursor*); 6792 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6793 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6794 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6795 int (*xBegin)(sqlite3_vtab *pVTab); 6796 int (*xSync)(sqlite3_vtab *pVTab); 6797 int (*xCommit)(sqlite3_vtab *pVTab); 6798 int (*xRollback)(sqlite3_vtab *pVTab); 6799 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6800 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6801 void **ppArg); 6802 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6803 /* The methods above are in version 1 of the sqlite_module object. Those 6804 ** below are for version 2 and greater. */ 6805 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6806 int (*xRelease)(sqlite3_vtab *pVTab, int); 6807 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6808 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6809 ** Those below are for version 3 and greater. */ 6810 int (*xShadowName)(const char*); 6811}; 6812 6813/* 6814** CAPI3REF: Virtual Table Indexing Information 6815** KEYWORDS: sqlite3_index_info 6816** 6817** The sqlite3_index_info structure and its substructures is used as part 6818** of the [virtual table] interface to 6819** pass information into and receive the reply from the [xBestIndex] 6820** method of a [virtual table module]. The fields under **Inputs** are the 6821** inputs to xBestIndex and are read-only. xBestIndex inserts its 6822** results into the **Outputs** fields. 6823** 6824** ^(The aConstraint[] array records WHERE clause constraints of the form: 6825** 6826** <blockquote>column OP expr</blockquote> 6827** 6828** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6829** stored in aConstraint[].op using one of the 6830** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6831** ^(The index of the column is stored in 6832** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6833** expr on the right-hand side can be evaluated (and thus the constraint 6834** is usable) and false if it cannot.)^ 6835** 6836** ^The optimizer automatically inverts terms of the form "expr OP column" 6837** and makes other simplifications to the WHERE clause in an attempt to 6838** get as many WHERE clause terms into the form shown above as possible. 6839** ^The aConstraint[] array only reports WHERE clause terms that are 6840** relevant to the particular virtual table being queried. 6841** 6842** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6843** ^Each term of aOrderBy records a column of the ORDER BY clause. 6844** 6845** The colUsed field indicates which columns of the virtual table may be 6846** required by the current scan. Virtual table columns are numbered from 6847** zero in the order in which they appear within the CREATE TABLE statement 6848** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6849** the corresponding bit is set within the colUsed mask if the column may be 6850** required by SQLite. If the table has at least 64 columns and any column 6851** to the right of the first 63 is required, then bit 63 of colUsed is also 6852** set. In other words, column iCol may be required if the expression 6853** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6854** non-zero. 6855** 6856** The [xBestIndex] method must fill aConstraintUsage[] with information 6857** about what parameters to pass to xFilter. ^If argvIndex>0 then 6858** the right-hand side of the corresponding aConstraint[] is evaluated 6859** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6860** is true, then the constraint is assumed to be fully handled by the 6861** virtual table and might not be checked again by the byte code.)^ ^(The 6862** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6863** is left in its default setting of false, the constraint will always be 6864** checked separately in byte code. If the omit flag is change to true, then 6865** the constraint may or may not be checked in byte code. In other words, 6866** when the omit flag is true there is no guarantee that the constraint will 6867** not be checked again using byte code.)^ 6868** 6869** ^The idxNum and idxPtr values are recorded and passed into the 6870** [xFilter] method. 6871** ^[sqlite3_free()] is used to free idxPtr if and only if 6872** needToFreeIdxPtr is true. 6873** 6874** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6875** the correct order to satisfy the ORDER BY clause so that no separate 6876** sorting step is required. 6877** 6878** ^The estimatedCost value is an estimate of the cost of a particular 6879** strategy. A cost of N indicates that the cost of the strategy is similar 6880** to a linear scan of an SQLite table with N rows. A cost of log(N) 6881** indicates that the expense of the operation is similar to that of a 6882** binary search on a unique indexed field of an SQLite table with N rows. 6883** 6884** ^The estimatedRows value is an estimate of the number of rows that 6885** will be returned by the strategy. 6886** 6887** The xBestIndex method may optionally populate the idxFlags field with a 6888** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6889** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6890** assumes that the strategy may visit at most one row. 6891** 6892** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6893** SQLite also assumes that if a call to the xUpdate() method is made as 6894** part of the same statement to delete or update a virtual table row and the 6895** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6896** any database changes. In other words, if the xUpdate() returns 6897** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6898** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6899** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6900** the xUpdate method are automatically rolled back by SQLite. 6901** 6902** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6903** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6904** If a virtual table extension is 6905** used with an SQLite version earlier than 3.8.2, the results of attempting 6906** to read or write the estimatedRows field are undefined (but are likely 6907** to include crashing the application). The estimatedRows field should 6908** therefore only be used if [sqlite3_libversion_number()] returns a 6909** value greater than or equal to 3008002. Similarly, the idxFlags field 6910** was added for [version 3.9.0] ([dateof:3.9.0]). 6911** It may therefore only be used if 6912** sqlite3_libversion_number() returns a value greater than or equal to 6913** 3009000. 6914*/ 6915struct sqlite3_index_info { 6916 /* Inputs */ 6917 int nConstraint; /* Number of entries in aConstraint */ 6918 struct sqlite3_index_constraint { 6919 int iColumn; /* Column constrained. -1 for ROWID */ 6920 unsigned char op; /* Constraint operator */ 6921 unsigned char usable; /* True if this constraint is usable */ 6922 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6923 } *aConstraint; /* Table of WHERE clause constraints */ 6924 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6925 struct sqlite3_index_orderby { 6926 int iColumn; /* Column number */ 6927 unsigned char desc; /* True for DESC. False for ASC. */ 6928 } *aOrderBy; /* The ORDER BY clause */ 6929 /* Outputs */ 6930 struct sqlite3_index_constraint_usage { 6931 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6932 unsigned char omit; /* Do not code a test for this constraint */ 6933 } *aConstraintUsage; 6934 int idxNum; /* Number used to identify the index */ 6935 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6936 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6937 int orderByConsumed; /* True if output is already ordered */ 6938 double estimatedCost; /* Estimated cost of using this index */ 6939 /* Fields below are only available in SQLite 3.8.2 and later */ 6940 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6941 /* Fields below are only available in SQLite 3.9.0 and later */ 6942 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6943 /* Fields below are only available in SQLite 3.10.0 and later */ 6944 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6945}; 6946 6947/* 6948** CAPI3REF: Virtual Table Scan Flags 6949** 6950** Virtual table implementations are allowed to set the 6951** [sqlite3_index_info].idxFlags field to some combination of 6952** these bits. 6953*/ 6954#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6955 6956/* 6957** CAPI3REF: Virtual Table Constraint Operator Codes 6958** 6959** These macros define the allowed values for the 6960** [sqlite3_index_info].aConstraint[].op field. Each value represents 6961** an operator that is part of a constraint term in the wHERE clause of 6962** a query that uses a [virtual table]. 6963*/ 6964#define SQLITE_INDEX_CONSTRAINT_EQ 2 6965#define SQLITE_INDEX_CONSTRAINT_GT 4 6966#define SQLITE_INDEX_CONSTRAINT_LE 8 6967#define SQLITE_INDEX_CONSTRAINT_LT 16 6968#define SQLITE_INDEX_CONSTRAINT_GE 32 6969#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6970#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6971#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6972#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6973#define SQLITE_INDEX_CONSTRAINT_NE 68 6974#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6975#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6976#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6977#define SQLITE_INDEX_CONSTRAINT_IS 72 6978#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6979 6980/* 6981** CAPI3REF: Register A Virtual Table Implementation 6982** METHOD: sqlite3 6983** 6984** ^These routines are used to register a new [virtual table module] name. 6985** ^Module names must be registered before 6986** creating a new [virtual table] using the module and before using a 6987** preexisting [virtual table] for the module. 6988** 6989** ^The module name is registered on the [database connection] specified 6990** by the first parameter. ^The name of the module is given by the 6991** second parameter. ^The third parameter is a pointer to 6992** the implementation of the [virtual table module]. ^The fourth 6993** parameter is an arbitrary client data pointer that is passed through 6994** into the [xCreate] and [xConnect] methods of the virtual table module 6995** when a new virtual table is be being created or reinitialized. 6996** 6997** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6998** is a pointer to a destructor for the pClientData. ^SQLite will 6999** invoke the destructor function (if it is not NULL) when SQLite 7000** no longer needs the pClientData pointer. ^The destructor will also 7001** be invoked if the call to sqlite3_create_module_v2() fails. 7002** ^The sqlite3_create_module() 7003** interface is equivalent to sqlite3_create_module_v2() with a NULL 7004** destructor. 7005** 7006** ^If the third parameter (the pointer to the sqlite3_module object) is 7007** NULL then no new module is create and any existing modules with the 7008** same name are dropped. 7009** 7010** See also: [sqlite3_drop_modules()] 7011*/ 7012SQLITE_API int sqlite3_create_module( 7013 sqlite3 *db, /* SQLite connection to register module with */ 7014 const char *zName, /* Name of the module */ 7015 const sqlite3_module *p, /* Methods for the module */ 7016 void *pClientData /* Client data for xCreate/xConnect */ 7017); 7018SQLITE_API int sqlite3_create_module_v2( 7019 sqlite3 *db, /* SQLite connection to register module with */ 7020 const char *zName, /* Name of the module */ 7021 const sqlite3_module *p, /* Methods for the module */ 7022 void *pClientData, /* Client data for xCreate/xConnect */ 7023 void(*xDestroy)(void*) /* Module destructor function */ 7024); 7025 7026/* 7027** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7028** METHOD: sqlite3 7029** 7030** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7031** table modules from database connection D except those named on list L. 7032** The L parameter must be either NULL or a pointer to an array of pointers 7033** to strings where the array is terminated by a single NULL pointer. 7034** ^If the L parameter is NULL, then all virtual table modules are removed. 7035** 7036** See also: [sqlite3_create_module()] 7037*/ 7038SQLITE_API int sqlite3_drop_modules( 7039 sqlite3 *db, /* Remove modules from this connection */ 7040 const char **azKeep /* Except, do not remove the ones named here */ 7041); 7042 7043/* 7044** CAPI3REF: Virtual Table Instance Object 7045** KEYWORDS: sqlite3_vtab 7046** 7047** Every [virtual table module] implementation uses a subclass 7048** of this object to describe a particular instance 7049** of the [virtual table]. Each subclass will 7050** be tailored to the specific needs of the module implementation. 7051** The purpose of this superclass is to define certain fields that are 7052** common to all module implementations. 7053** 7054** ^Virtual tables methods can set an error message by assigning a 7055** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7056** take care that any prior string is freed by a call to [sqlite3_free()] 7057** prior to assigning a new string to zErrMsg. ^After the error message 7058** is delivered up to the client application, the string will be automatically 7059** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7060*/ 7061struct sqlite3_vtab { 7062 const sqlite3_module *pModule; /* The module for this virtual table */ 7063 int nRef; /* Number of open cursors */ 7064 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7065 /* Virtual table implementations will typically add additional fields */ 7066}; 7067 7068/* 7069** CAPI3REF: Virtual Table Cursor Object 7070** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7071** 7072** Every [virtual table module] implementation uses a subclass of the 7073** following structure to describe cursors that point into the 7074** [virtual table] and are used 7075** to loop through the virtual table. Cursors are created using the 7076** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7077** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7078** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7079** of the module. Each module implementation will define 7080** the content of a cursor structure to suit its own needs. 7081** 7082** This superclass exists in order to define fields of the cursor that 7083** are common to all implementations. 7084*/ 7085struct sqlite3_vtab_cursor { 7086 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7087 /* Virtual table implementations will typically add additional fields */ 7088}; 7089 7090/* 7091** CAPI3REF: Declare The Schema Of A Virtual Table 7092** 7093** ^The [xCreate] and [xConnect] methods of a 7094** [virtual table module] call this interface 7095** to declare the format (the names and datatypes of the columns) of 7096** the virtual tables they implement. 7097*/ 7098SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7099 7100/* 7101** CAPI3REF: Overload A Function For A Virtual Table 7102** METHOD: sqlite3 7103** 7104** ^(Virtual tables can provide alternative implementations of functions 7105** using the [xFindFunction] method of the [virtual table module]. 7106** But global versions of those functions 7107** must exist in order to be overloaded.)^ 7108** 7109** ^(This API makes sure a global version of a function with a particular 7110** name and number of parameters exists. If no such function exists 7111** before this API is called, a new function is created.)^ ^The implementation 7112** of the new function always causes an exception to be thrown. So 7113** the new function is not good for anything by itself. Its only 7114** purpose is to be a placeholder function that can be overloaded 7115** by a [virtual table]. 7116*/ 7117SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7118 7119/* 7120** The interface to the virtual-table mechanism defined above (back up 7121** to a comment remarkably similar to this one) is currently considered 7122** to be experimental. The interface might change in incompatible ways. 7123** If this is a problem for you, do not use the interface at this time. 7124** 7125** When the virtual-table mechanism stabilizes, we will declare the 7126** interface fixed, support it indefinitely, and remove this comment. 7127*/ 7128 7129/* 7130** CAPI3REF: A Handle To An Open BLOB 7131** KEYWORDS: {BLOB handle} {BLOB handles} 7132** 7133** An instance of this object represents an open BLOB on which 7134** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7135** ^Objects of this type are created by [sqlite3_blob_open()] 7136** and destroyed by [sqlite3_blob_close()]. 7137** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7138** can be used to read or write small subsections of the BLOB. 7139** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7140*/ 7141typedef struct sqlite3_blob sqlite3_blob; 7142 7143/* 7144** CAPI3REF: Open A BLOB For Incremental I/O 7145** METHOD: sqlite3 7146** CONSTRUCTOR: sqlite3_blob 7147** 7148** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7149** in row iRow, column zColumn, table zTable in database zDb; 7150** in other words, the same BLOB that would be selected by: 7151** 7152** <pre> 7153** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7154** </pre>)^ 7155** 7156** ^(Parameter zDb is not the filename that contains the database, but 7157** rather the symbolic name of the database. For attached databases, this is 7158** the name that appears after the AS keyword in the [ATTACH] statement. 7159** For the main database file, the database name is "main". For TEMP 7160** tables, the database name is "temp".)^ 7161** 7162** ^If the flags parameter is non-zero, then the BLOB is opened for read 7163** and write access. ^If the flags parameter is zero, the BLOB is opened for 7164** read-only access. 7165** 7166** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7167** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7168** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7169** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7170** on *ppBlob after this function it returns. 7171** 7172** This function fails with SQLITE_ERROR if any of the following are true: 7173** <ul> 7174** <li> ^(Database zDb does not exist)^, 7175** <li> ^(Table zTable does not exist within database zDb)^, 7176** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7177** <li> ^(Column zColumn does not exist)^, 7178** <li> ^(Row iRow is not present in the table)^, 7179** <li> ^(The specified column of row iRow contains a value that is not 7180** a TEXT or BLOB value)^, 7181** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7182** constraint and the blob is being opened for read/write access)^, 7183** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7184** column zColumn is part of a [child key] definition and the blob is 7185** being opened for read/write access)^. 7186** </ul> 7187** 7188** ^Unless it returns SQLITE_MISUSE, this function sets the 7189** [database connection] error code and message accessible via 7190** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7191** 7192** A BLOB referenced by sqlite3_blob_open() may be read using the 7193** [sqlite3_blob_read()] interface and modified by using 7194** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7195** different row of the same table using the [sqlite3_blob_reopen()] 7196** interface. However, the column, table, or database of a [BLOB handle] 7197** cannot be changed after the [BLOB handle] is opened. 7198** 7199** ^(If the row that a BLOB handle points to is modified by an 7200** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7201** then the BLOB handle is marked as "expired". 7202** This is true if any column of the row is changed, even a column 7203** other than the one the BLOB handle is open on.)^ 7204** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7205** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7206** ^(Changes written into a BLOB prior to the BLOB expiring are not 7207** rolled back by the expiration of the BLOB. Such changes will eventually 7208** commit if the transaction continues to completion.)^ 7209** 7210** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7211** the opened blob. ^The size of a blob may not be changed by this 7212** interface. Use the [UPDATE] SQL command to change the size of a 7213** blob. 7214** 7215** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7216** and the built-in [zeroblob] SQL function may be used to create a 7217** zero-filled blob to read or write using the incremental-blob interface. 7218** 7219** To avoid a resource leak, every open [BLOB handle] should eventually 7220** be released by a call to [sqlite3_blob_close()]. 7221** 7222** See also: [sqlite3_blob_close()], 7223** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7224** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7225*/ 7226SQLITE_API int sqlite3_blob_open( 7227 sqlite3*, 7228 const char *zDb, 7229 const char *zTable, 7230 const char *zColumn, 7231 sqlite3_int64 iRow, 7232 int flags, 7233 sqlite3_blob **ppBlob 7234); 7235 7236/* 7237** CAPI3REF: Move a BLOB Handle to a New Row 7238** METHOD: sqlite3_blob 7239** 7240** ^This function is used to move an existing [BLOB handle] so that it points 7241** to a different row of the same database table. ^The new row is identified 7242** by the rowid value passed as the second argument. Only the row can be 7243** changed. ^The database, table and column on which the blob handle is open 7244** remain the same. Moving an existing [BLOB handle] to a new row is 7245** faster than closing the existing handle and opening a new one. 7246** 7247** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7248** it must exist and there must be either a blob or text value stored in 7249** the nominated column.)^ ^If the new row is not present in the table, or if 7250** it does not contain a blob or text value, or if another error occurs, an 7251** SQLite error code is returned and the blob handle is considered aborted. 7252** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7253** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7254** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7255** always returns zero. 7256** 7257** ^This function sets the database handle error code and message. 7258*/ 7259SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7260 7261/* 7262** CAPI3REF: Close A BLOB Handle 7263** DESTRUCTOR: sqlite3_blob 7264** 7265** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7266** unconditionally. Even if this routine returns an error code, the 7267** handle is still closed.)^ 7268** 7269** ^If the blob handle being closed was opened for read-write access, and if 7270** the database is in auto-commit mode and there are no other open read-write 7271** blob handles or active write statements, the current transaction is 7272** committed. ^If an error occurs while committing the transaction, an error 7273** code is returned and the transaction rolled back. 7274** 7275** Calling this function with an argument that is not a NULL pointer or an 7276** open blob handle results in undefined behaviour. ^Calling this routine 7277** with a null pointer (such as would be returned by a failed call to 7278** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7279** is passed a valid open blob handle, the values returned by the 7280** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7281*/ 7282SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7283 7284/* 7285** CAPI3REF: Return The Size Of An Open BLOB 7286** METHOD: sqlite3_blob 7287** 7288** ^Returns the size in bytes of the BLOB accessible via the 7289** successfully opened [BLOB handle] in its only argument. ^The 7290** incremental blob I/O routines can only read or overwriting existing 7291** blob content; they cannot change the size of a blob. 7292** 7293** This routine only works on a [BLOB handle] which has been created 7294** by a prior successful call to [sqlite3_blob_open()] and which has not 7295** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7296** to this routine results in undefined and probably undesirable behavior. 7297*/ 7298SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7299 7300/* 7301** CAPI3REF: Read Data From A BLOB Incrementally 7302** METHOD: sqlite3_blob 7303** 7304** ^(This function is used to read data from an open [BLOB handle] into a 7305** caller-supplied buffer. N bytes of data are copied into buffer Z 7306** from the open BLOB, starting at offset iOffset.)^ 7307** 7308** ^If offset iOffset is less than N bytes from the end of the BLOB, 7309** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7310** less than zero, [SQLITE_ERROR] is returned and no data is read. 7311** ^The size of the blob (and hence the maximum value of N+iOffset) 7312** can be determined using the [sqlite3_blob_bytes()] interface. 7313** 7314** ^An attempt to read from an expired [BLOB handle] fails with an 7315** error code of [SQLITE_ABORT]. 7316** 7317** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7318** Otherwise, an [error code] or an [extended error code] is returned.)^ 7319** 7320** This routine only works on a [BLOB handle] which has been created 7321** by a prior successful call to [sqlite3_blob_open()] and which has not 7322** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7323** to this routine results in undefined and probably undesirable behavior. 7324** 7325** See also: [sqlite3_blob_write()]. 7326*/ 7327SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7328 7329/* 7330** CAPI3REF: Write Data Into A BLOB Incrementally 7331** METHOD: sqlite3_blob 7332** 7333** ^(This function is used to write data into an open [BLOB handle] from a 7334** caller-supplied buffer. N bytes of data are copied from the buffer Z 7335** into the open BLOB, starting at offset iOffset.)^ 7336** 7337** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7338** Otherwise, an [error code] or an [extended error code] is returned.)^ 7339** ^Unless SQLITE_MISUSE is returned, this function sets the 7340** [database connection] error code and message accessible via 7341** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7342** 7343** ^If the [BLOB handle] passed as the first argument was not opened for 7344** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7345** this function returns [SQLITE_READONLY]. 7346** 7347** This function may only modify the contents of the BLOB; it is 7348** not possible to increase the size of a BLOB using this API. 7349** ^If offset iOffset is less than N bytes from the end of the BLOB, 7350** [SQLITE_ERROR] is returned and no data is written. The size of the 7351** BLOB (and hence the maximum value of N+iOffset) can be determined 7352** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7353** than zero [SQLITE_ERROR] is returned and no data is written. 7354** 7355** ^An attempt to write to an expired [BLOB handle] fails with an 7356** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7357** before the [BLOB handle] expired are not rolled back by the 7358** expiration of the handle, though of course those changes might 7359** have been overwritten by the statement that expired the BLOB handle 7360** or by other independent statements. 7361** 7362** This routine only works on a [BLOB handle] which has been created 7363** by a prior successful call to [sqlite3_blob_open()] and which has not 7364** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7365** to this routine results in undefined and probably undesirable behavior. 7366** 7367** See also: [sqlite3_blob_read()]. 7368*/ 7369SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7370 7371/* 7372** CAPI3REF: Virtual File System Objects 7373** 7374** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7375** that SQLite uses to interact 7376** with the underlying operating system. Most SQLite builds come with a 7377** single default VFS that is appropriate for the host computer. 7378** New VFSes can be registered and existing VFSes can be unregistered. 7379** The following interfaces are provided. 7380** 7381** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7382** ^Names are case sensitive. 7383** ^Names are zero-terminated UTF-8 strings. 7384** ^If there is no match, a NULL pointer is returned. 7385** ^If zVfsName is NULL then the default VFS is returned. 7386** 7387** ^New VFSes are registered with sqlite3_vfs_register(). 7388** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7389** ^The same VFS can be registered multiple times without injury. 7390** ^To make an existing VFS into the default VFS, register it again 7391** with the makeDflt flag set. If two different VFSes with the 7392** same name are registered, the behavior is undefined. If a 7393** VFS is registered with a name that is NULL or an empty string, 7394** then the behavior is undefined. 7395** 7396** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7397** ^(If the default VFS is unregistered, another VFS is chosen as 7398** the default. The choice for the new VFS is arbitrary.)^ 7399*/ 7400SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7401SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7402SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7403 7404/* 7405** CAPI3REF: Mutexes 7406** 7407** The SQLite core uses these routines for thread 7408** synchronization. Though they are intended for internal 7409** use by SQLite, code that links against SQLite is 7410** permitted to use any of these routines. 7411** 7412** The SQLite source code contains multiple implementations 7413** of these mutex routines. An appropriate implementation 7414** is selected automatically at compile-time. The following 7415** implementations are available in the SQLite core: 7416** 7417** <ul> 7418** <li> SQLITE_MUTEX_PTHREADS 7419** <li> SQLITE_MUTEX_W32 7420** <li> SQLITE_MUTEX_NOOP 7421** </ul> 7422** 7423** The SQLITE_MUTEX_NOOP implementation is a set of routines 7424** that does no real locking and is appropriate for use in 7425** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7426** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7427** and Windows. 7428** 7429** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7430** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7431** implementation is included with the library. In this case the 7432** application must supply a custom mutex implementation using the 7433** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7434** before calling sqlite3_initialize() or any other public sqlite3_ 7435** function that calls sqlite3_initialize(). 7436** 7437** ^The sqlite3_mutex_alloc() routine allocates a new 7438** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7439** routine returns NULL if it is unable to allocate the requested 7440** mutex. The argument to sqlite3_mutex_alloc() must one of these 7441** integer constants: 7442** 7443** <ul> 7444** <li> SQLITE_MUTEX_FAST 7445** <li> SQLITE_MUTEX_RECURSIVE 7446** <li> SQLITE_MUTEX_STATIC_MAIN 7447** <li> SQLITE_MUTEX_STATIC_MEM 7448** <li> SQLITE_MUTEX_STATIC_OPEN 7449** <li> SQLITE_MUTEX_STATIC_PRNG 7450** <li> SQLITE_MUTEX_STATIC_LRU 7451** <li> SQLITE_MUTEX_STATIC_PMEM 7452** <li> SQLITE_MUTEX_STATIC_APP1 7453** <li> SQLITE_MUTEX_STATIC_APP2 7454** <li> SQLITE_MUTEX_STATIC_APP3 7455** <li> SQLITE_MUTEX_STATIC_VFS1 7456** <li> SQLITE_MUTEX_STATIC_VFS2 7457** <li> SQLITE_MUTEX_STATIC_VFS3 7458** </ul> 7459** 7460** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7461** cause sqlite3_mutex_alloc() to create 7462** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7463** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7464** The mutex implementation does not need to make a distinction 7465** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7466** not want to. SQLite will only request a recursive mutex in 7467** cases where it really needs one. If a faster non-recursive mutex 7468** implementation is available on the host platform, the mutex subsystem 7469** might return such a mutex in response to SQLITE_MUTEX_FAST. 7470** 7471** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7472** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7473** a pointer to a static preexisting mutex. ^Nine static mutexes are 7474** used by the current version of SQLite. Future versions of SQLite 7475** may add additional static mutexes. Static mutexes are for internal 7476** use by SQLite only. Applications that use SQLite mutexes should 7477** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7478** SQLITE_MUTEX_RECURSIVE. 7479** 7480** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7481** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7482** returns a different mutex on every call. ^For the static 7483** mutex types, the same mutex is returned on every call that has 7484** the same type number. 7485** 7486** ^The sqlite3_mutex_free() routine deallocates a previously 7487** allocated dynamic mutex. Attempting to deallocate a static 7488** mutex results in undefined behavior. 7489** 7490** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7491** to enter a mutex. ^If another thread is already within the mutex, 7492** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7493** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7494** upon successful entry. ^(Mutexes created using 7495** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7496** In such cases, the 7497** mutex must be exited an equal number of times before another thread 7498** can enter.)^ If the same thread tries to enter any mutex other 7499** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7500** 7501** ^(Some systems (for example, Windows 95) do not support the operation 7502** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7503** will always return SQLITE_BUSY. The SQLite core only ever uses 7504** sqlite3_mutex_try() as an optimization so this is acceptable 7505** behavior.)^ 7506** 7507** ^The sqlite3_mutex_leave() routine exits a mutex that was 7508** previously entered by the same thread. The behavior 7509** is undefined if the mutex is not currently entered by the 7510** calling thread or is not currently allocated. 7511** 7512** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7513** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7514** behave as no-ops. 7515** 7516** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7517*/ 7518SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7519SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7520SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7521SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7522SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7523 7524/* 7525** CAPI3REF: Mutex Methods Object 7526** 7527** An instance of this structure defines the low-level routines 7528** used to allocate and use mutexes. 7529** 7530** Usually, the default mutex implementations provided by SQLite are 7531** sufficient, however the application has the option of substituting a custom 7532** implementation for specialized deployments or systems for which SQLite 7533** does not provide a suitable implementation. In this case, the application 7534** creates and populates an instance of this structure to pass 7535** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7536** Additionally, an instance of this structure can be used as an 7537** output variable when querying the system for the current mutex 7538** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7539** 7540** ^The xMutexInit method defined by this structure is invoked as 7541** part of system initialization by the sqlite3_initialize() function. 7542** ^The xMutexInit routine is called by SQLite exactly once for each 7543** effective call to [sqlite3_initialize()]. 7544** 7545** ^The xMutexEnd method defined by this structure is invoked as 7546** part of system shutdown by the sqlite3_shutdown() function. The 7547** implementation of this method is expected to release all outstanding 7548** resources obtained by the mutex methods implementation, especially 7549** those obtained by the xMutexInit method. ^The xMutexEnd() 7550** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7551** 7552** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7553** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7554** xMutexNotheld) implement the following interfaces (respectively): 7555** 7556** <ul> 7557** <li> [sqlite3_mutex_alloc()] </li> 7558** <li> [sqlite3_mutex_free()] </li> 7559** <li> [sqlite3_mutex_enter()] </li> 7560** <li> [sqlite3_mutex_try()] </li> 7561** <li> [sqlite3_mutex_leave()] </li> 7562** <li> [sqlite3_mutex_held()] </li> 7563** <li> [sqlite3_mutex_notheld()] </li> 7564** </ul>)^ 7565** 7566** The only difference is that the public sqlite3_XXX functions enumerated 7567** above silently ignore any invocations that pass a NULL pointer instead 7568** of a valid mutex handle. The implementations of the methods defined 7569** by this structure are not required to handle this case. The results 7570** of passing a NULL pointer instead of a valid mutex handle are undefined 7571** (i.e. it is acceptable to provide an implementation that segfaults if 7572** it is passed a NULL pointer). 7573** 7574** The xMutexInit() method must be threadsafe. It must be harmless to 7575** invoke xMutexInit() multiple times within the same process and without 7576** intervening calls to xMutexEnd(). Second and subsequent calls to 7577** xMutexInit() must be no-ops. 7578** 7579** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7580** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7581** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7582** memory allocation for a fast or recursive mutex. 7583** 7584** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7585** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7586** If xMutexInit fails in any way, it is expected to clean up after itself 7587** prior to returning. 7588*/ 7589typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7590struct sqlite3_mutex_methods { 7591 int (*xMutexInit)(void); 7592 int (*xMutexEnd)(void); 7593 sqlite3_mutex *(*xMutexAlloc)(int); 7594 void (*xMutexFree)(sqlite3_mutex *); 7595 void (*xMutexEnter)(sqlite3_mutex *); 7596 int (*xMutexTry)(sqlite3_mutex *); 7597 void (*xMutexLeave)(sqlite3_mutex *); 7598 int (*xMutexHeld)(sqlite3_mutex *); 7599 int (*xMutexNotheld)(sqlite3_mutex *); 7600}; 7601 7602/* 7603** CAPI3REF: Mutex Verification Routines 7604** 7605** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7606** are intended for use inside assert() statements. The SQLite core 7607** never uses these routines except inside an assert() and applications 7608** are advised to follow the lead of the core. The SQLite core only 7609** provides implementations for these routines when it is compiled 7610** with the SQLITE_DEBUG flag. External mutex implementations 7611** are only required to provide these routines if SQLITE_DEBUG is 7612** defined and if NDEBUG is not defined. 7613** 7614** These routines should return true if the mutex in their argument 7615** is held or not held, respectively, by the calling thread. 7616** 7617** The implementation is not required to provide versions of these 7618** routines that actually work. If the implementation does not provide working 7619** versions of these routines, it should at least provide stubs that always 7620** return true so that one does not get spurious assertion failures. 7621** 7622** If the argument to sqlite3_mutex_held() is a NULL pointer then 7623** the routine should return 1. This seems counter-intuitive since 7624** clearly the mutex cannot be held if it does not exist. But 7625** the reason the mutex does not exist is because the build is not 7626** using mutexes. And we do not want the assert() containing the 7627** call to sqlite3_mutex_held() to fail, so a non-zero return is 7628** the appropriate thing to do. The sqlite3_mutex_notheld() 7629** interface should also return 1 when given a NULL pointer. 7630*/ 7631#ifndef NDEBUG 7632SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7633SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7634#endif 7635 7636/* 7637** CAPI3REF: Mutex Types 7638** 7639** The [sqlite3_mutex_alloc()] interface takes a single argument 7640** which is one of these integer constants. 7641** 7642** The set of static mutexes may change from one SQLite release to the 7643** next. Applications that override the built-in mutex logic must be 7644** prepared to accommodate additional static mutexes. 7645*/ 7646#define SQLITE_MUTEX_FAST 0 7647#define SQLITE_MUTEX_RECURSIVE 1 7648#define SQLITE_MUTEX_STATIC_MAIN 2 7649#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7650#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7651#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7652#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7653#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7654#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7655#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7656#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7657#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7658#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7659#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7660#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7661#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7662 7663/* Legacy compatibility: */ 7664#define SQLITE_MUTEX_STATIC_MASTER 2 7665 7666 7667/* 7668** CAPI3REF: Retrieve the mutex for a database connection 7669** METHOD: sqlite3 7670** 7671** ^This interface returns a pointer the [sqlite3_mutex] object that 7672** serializes access to the [database connection] given in the argument 7673** when the [threading mode] is Serialized. 7674** ^If the [threading mode] is Single-thread or Multi-thread then this 7675** routine returns a NULL pointer. 7676*/ 7677SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7678 7679/* 7680** CAPI3REF: Low-Level Control Of Database Files 7681** METHOD: sqlite3 7682** KEYWORDS: {file control} 7683** 7684** ^The [sqlite3_file_control()] interface makes a direct call to the 7685** xFileControl method for the [sqlite3_io_methods] object associated 7686** with a particular database identified by the second argument. ^The 7687** name of the database is "main" for the main database or "temp" for the 7688** TEMP database, or the name that appears after the AS keyword for 7689** databases that are added using the [ATTACH] SQL command. 7690** ^A NULL pointer can be used in place of "main" to refer to the 7691** main database file. 7692** ^The third and fourth parameters to this routine 7693** are passed directly through to the second and third parameters of 7694** the xFileControl method. ^The return value of the xFileControl 7695** method becomes the return value of this routine. 7696** 7697** A few opcodes for [sqlite3_file_control()] are handled directly 7698** by the SQLite core and never invoke the 7699** sqlite3_io_methods.xFileControl method. 7700** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7701** a pointer to the underlying [sqlite3_file] object to be written into 7702** the space pointed to by the 4th parameter. The 7703** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7704** the [sqlite3_file] object associated with the journal file instead of 7705** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7706** a pointer to the underlying [sqlite3_vfs] object for the file. 7707** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7708** from the pager. 7709** 7710** ^If the second parameter (zDbName) does not match the name of any 7711** open database file, then SQLITE_ERROR is returned. ^This error 7712** code is not remembered and will not be recalled by [sqlite3_errcode()] 7713** or [sqlite3_errmsg()]. The underlying xFileControl method might 7714** also return SQLITE_ERROR. There is no way to distinguish between 7715** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7716** xFileControl method. 7717** 7718** See also: [file control opcodes] 7719*/ 7720SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7721 7722/* 7723** CAPI3REF: Testing Interface 7724** 7725** ^The sqlite3_test_control() interface is used to read out internal 7726** state of SQLite and to inject faults into SQLite for testing 7727** purposes. ^The first parameter is an operation code that determines 7728** the number, meaning, and operation of all subsequent parameters. 7729** 7730** This interface is not for use by applications. It exists solely 7731** for verifying the correct operation of the SQLite library. Depending 7732** on how the SQLite library is compiled, this interface might not exist. 7733** 7734** The details of the operation codes, their meanings, the parameters 7735** they take, and what they do are all subject to change without notice. 7736** Unlike most of the SQLite API, this function is not guaranteed to 7737** operate consistently from one release to the next. 7738*/ 7739SQLITE_API int sqlite3_test_control(int op, ...); 7740 7741/* 7742** CAPI3REF: Testing Interface Operation Codes 7743** 7744** These constants are the valid operation code parameters used 7745** as the first argument to [sqlite3_test_control()]. 7746** 7747** These parameters and their meanings are subject to change 7748** without notice. These values are for testing purposes only. 7749** Applications should not use any of these parameters or the 7750** [sqlite3_test_control()] interface. 7751*/ 7752#define SQLITE_TESTCTRL_FIRST 5 7753#define SQLITE_TESTCTRL_PRNG_SAVE 5 7754#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7755#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7756#define SQLITE_TESTCTRL_BITVEC_TEST 8 7757#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7758#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7759#define SQLITE_TESTCTRL_PENDING_BYTE 11 7760#define SQLITE_TESTCTRL_ASSERT 12 7761#define SQLITE_TESTCTRL_ALWAYS 13 7762#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 7763#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7764#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7765#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7766#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7767#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7768#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7769#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7770#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7771#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7772#define SQLITE_TESTCTRL_BYTEORDER 22 7773#define SQLITE_TESTCTRL_ISINIT 23 7774#define SQLITE_TESTCTRL_SORTER_MMAP 24 7775#define SQLITE_TESTCTRL_IMPOSTER 25 7776#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7777#define SQLITE_TESTCTRL_RESULT_INTREAL 27 7778#define SQLITE_TESTCTRL_PRNG_SEED 28 7779#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7780#define SQLITE_TESTCTRL_SEEK_COUNT 30 7781#define SQLITE_TESTCTRL_TRACEFLAGS 31 7782#define SQLITE_TESTCTRL_LAST 31 /* Largest TESTCTRL */ 7783 7784/* 7785** CAPI3REF: SQL Keyword Checking 7786** 7787** These routines provide access to the set of SQL language keywords 7788** recognized by SQLite. Applications can uses these routines to determine 7789** whether or not a specific identifier needs to be escaped (for example, 7790** by enclosing in double-quotes) so as not to confuse the parser. 7791** 7792** The sqlite3_keyword_count() interface returns the number of distinct 7793** keywords understood by SQLite. 7794** 7795** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7796** makes *Z point to that keyword expressed as UTF8 and writes the number 7797** of bytes in the keyword into *L. The string that *Z points to is not 7798** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7799** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7800** or L are NULL or invalid pointers then calls to 7801** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7802** 7803** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7804** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7805** if it is and zero if not. 7806** 7807** The parser used by SQLite is forgiving. It is often possible to use 7808** a keyword as an identifier as long as such use does not result in a 7809** parsing ambiguity. For example, the statement 7810** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7811** creates a new table named "BEGIN" with three columns named 7812** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7813** using keywords as identifiers. Common techniques used to avoid keyword 7814** name collisions include: 7815** <ul> 7816** <li> Put all identifier names inside double-quotes. This is the official 7817** SQL way to escape identifier names. 7818** <li> Put identifier names inside [...]. This is not standard SQL, 7819** but it is what SQL Server does and so lots of programmers use this 7820** technique. 7821** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7822** with "Z". 7823** <li> Include a digit somewhere in every identifier name. 7824** </ul> 7825** 7826** Note that the number of keywords understood by SQLite can depend on 7827** compile-time options. For example, "VACUUM" is not a keyword if 7828** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7829** new keywords may be added to future releases of SQLite. 7830*/ 7831SQLITE_API int sqlite3_keyword_count(void); 7832SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7833SQLITE_API int sqlite3_keyword_check(const char*,int); 7834 7835/* 7836** CAPI3REF: Dynamic String Object 7837** KEYWORDS: {dynamic string} 7838** 7839** An instance of the sqlite3_str object contains a dynamically-sized 7840** string under construction. 7841** 7842** The lifecycle of an sqlite3_str object is as follows: 7843** <ol> 7844** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7845** <li> ^Text is appended to the sqlite3_str object using various 7846** methods, such as [sqlite3_str_appendf()]. 7847** <li> ^The sqlite3_str object is destroyed and the string it created 7848** is returned using the [sqlite3_str_finish()] interface. 7849** </ol> 7850*/ 7851typedef struct sqlite3_str sqlite3_str; 7852 7853/* 7854** CAPI3REF: Create A New Dynamic String Object 7855** CONSTRUCTOR: sqlite3_str 7856** 7857** ^The [sqlite3_str_new(D)] interface allocates and initializes 7858** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7859** [sqlite3_str_new()] must be freed by a subsequent call to 7860** [sqlite3_str_finish(X)]. 7861** 7862** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7863** valid [sqlite3_str] object, though in the event of an out-of-memory 7864** error the returned object might be a special singleton that will 7865** silently reject new text, always return SQLITE_NOMEM from 7866** [sqlite3_str_errcode()], always return 0 for 7867** [sqlite3_str_length()], and always return NULL from 7868** [sqlite3_str_finish(X)]. It is always safe to use the value 7869** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7870** to any of the other [sqlite3_str] methods. 7871** 7872** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7873** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7874** length of the string contained in the [sqlite3_str] object will be 7875** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7876** of [SQLITE_MAX_LENGTH]. 7877*/ 7878SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7879 7880/* 7881** CAPI3REF: Finalize A Dynamic String 7882** DESTRUCTOR: sqlite3_str 7883** 7884** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7885** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7886** that contains the constructed string. The calling application should 7887** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7888** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7889** errors were encountered during construction of the string. ^The 7890** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7891** string in [sqlite3_str] object X is zero bytes long. 7892*/ 7893SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7894 7895/* 7896** CAPI3REF: Add Content To A Dynamic String 7897** METHOD: sqlite3_str 7898** 7899** These interfaces add content to an sqlite3_str object previously obtained 7900** from [sqlite3_str_new()]. 7901** 7902** ^The [sqlite3_str_appendf(X,F,...)] and 7903** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7904** functionality of SQLite to append formatted text onto the end of 7905** [sqlite3_str] object X. 7906** 7907** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7908** onto the end of the [sqlite3_str] object X. N must be non-negative. 7909** S must contain at least N non-zero bytes of content. To append a 7910** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7911** method instead. 7912** 7913** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7914** zero-terminated string S onto the end of [sqlite3_str] object X. 7915** 7916** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7917** single-byte character C onto the end of [sqlite3_str] object X. 7918** ^This method can be used, for example, to add whitespace indentation. 7919** 7920** ^The [sqlite3_str_reset(X)] method resets the string under construction 7921** inside [sqlite3_str] object X back to zero bytes in length. 7922** 7923** These methods do not return a result code. ^If an error occurs, that fact 7924** is recorded in the [sqlite3_str] object and can be recovered by a 7925** subsequent call to [sqlite3_str_errcode(X)]. 7926*/ 7927SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7928SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7929SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7930SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7931SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7932SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7933 7934/* 7935** CAPI3REF: Status Of A Dynamic String 7936** METHOD: sqlite3_str 7937** 7938** These interfaces return the current status of an [sqlite3_str] object. 7939** 7940** ^If any prior errors have occurred while constructing the dynamic string 7941** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7942** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7943** [SQLITE_NOMEM] following any out-of-memory error, or 7944** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7945** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7946** 7947** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7948** of the dynamic string under construction in [sqlite3_str] object X. 7949** ^The length returned by [sqlite3_str_length(X)] does not include the 7950** zero-termination byte. 7951** 7952** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7953** content of the dynamic string under construction in X. The value 7954** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7955** and might be freed or altered by any subsequent method on the same 7956** [sqlite3_str] object. Applications must not used the pointer returned 7957** [sqlite3_str_value(X)] after any subsequent method call on the same 7958** object. ^Applications may change the content of the string returned 7959** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7960** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7961** write any byte after any subsequent sqlite3_str method call. 7962*/ 7963SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7964SQLITE_API int sqlite3_str_length(sqlite3_str*); 7965SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7966 7967/* 7968** CAPI3REF: SQLite Runtime Status 7969** 7970** ^These interfaces are used to retrieve runtime status information 7971** about the performance of SQLite, and optionally to reset various 7972** highwater marks. ^The first argument is an integer code for 7973** the specific parameter to measure. ^(Recognized integer codes 7974** are of the form [status parameters | SQLITE_STATUS_...].)^ 7975** ^The current value of the parameter is returned into *pCurrent. 7976** ^The highest recorded value is returned in *pHighwater. ^If the 7977** resetFlag is true, then the highest record value is reset after 7978** *pHighwater is written. ^(Some parameters do not record the highest 7979** value. For those parameters 7980** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7981** ^(Other parameters record only the highwater mark and not the current 7982** value. For these latter parameters nothing is written into *pCurrent.)^ 7983** 7984** ^The sqlite3_status() and sqlite3_status64() routines return 7985** SQLITE_OK on success and a non-zero [error code] on failure. 7986** 7987** If either the current value or the highwater mark is too large to 7988** be represented by a 32-bit integer, then the values returned by 7989** sqlite3_status() are undefined. 7990** 7991** See also: [sqlite3_db_status()] 7992*/ 7993SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7994SQLITE_API int sqlite3_status64( 7995 int op, 7996 sqlite3_int64 *pCurrent, 7997 sqlite3_int64 *pHighwater, 7998 int resetFlag 7999); 8000 8001 8002/* 8003** CAPI3REF: Status Parameters 8004** KEYWORDS: {status parameters} 8005** 8006** These integer constants designate various run-time status parameters 8007** that can be returned by [sqlite3_status()]. 8008** 8009** <dl> 8010** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8011** <dd>This parameter is the current amount of memory checked out 8012** using [sqlite3_malloc()], either directly or indirectly. The 8013** figure includes calls made to [sqlite3_malloc()] by the application 8014** and internal memory usage by the SQLite library. Auxiliary page-cache 8015** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8016** this parameter. The amount returned is the sum of the allocation 8017** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8018** 8019** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8020** <dd>This parameter records the largest memory allocation request 8021** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8022** internal equivalents). Only the value returned in the 8023** *pHighwater parameter to [sqlite3_status()] is of interest. 8024** The value written into the *pCurrent parameter is undefined.</dd>)^ 8025** 8026** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8027** <dd>This parameter records the number of separate memory allocations 8028** currently checked out.</dd>)^ 8029** 8030** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8031** <dd>This parameter returns the number of pages used out of the 8032** [pagecache memory allocator] that was configured using 8033** [SQLITE_CONFIG_PAGECACHE]. The 8034** value returned is in pages, not in bytes.</dd>)^ 8035** 8036** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8037** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8038** <dd>This parameter returns the number of bytes of page cache 8039** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8040** buffer and where forced to overflow to [sqlite3_malloc()]. The 8041** returned value includes allocations that overflowed because they 8042** where too large (they were larger than the "sz" parameter to 8043** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8044** no space was left in the page cache.</dd>)^ 8045** 8046** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8047** <dd>This parameter records the largest memory allocation request 8048** handed to the [pagecache memory allocator]. Only the value returned in the 8049** *pHighwater parameter to [sqlite3_status()] is of interest. 8050** The value written into the *pCurrent parameter is undefined.</dd>)^ 8051** 8052** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8053** <dd>No longer used.</dd> 8054** 8055** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8056** <dd>No longer used.</dd> 8057** 8058** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8059** <dd>No longer used.</dd> 8060** 8061** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8062** <dd>The *pHighwater parameter records the deepest parser stack. 8063** The *pCurrent value is undefined. The *pHighwater value is only 8064** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8065** </dl> 8066** 8067** New status parameters may be added from time to time. 8068*/ 8069#define SQLITE_STATUS_MEMORY_USED 0 8070#define SQLITE_STATUS_PAGECACHE_USED 1 8071#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8072#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8073#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8074#define SQLITE_STATUS_MALLOC_SIZE 5 8075#define SQLITE_STATUS_PARSER_STACK 6 8076#define SQLITE_STATUS_PAGECACHE_SIZE 7 8077#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8078#define SQLITE_STATUS_MALLOC_COUNT 9 8079 8080/* 8081** CAPI3REF: Database Connection Status 8082** METHOD: sqlite3 8083** 8084** ^This interface is used to retrieve runtime status information 8085** about a single [database connection]. ^The first argument is the 8086** database connection object to be interrogated. ^The second argument 8087** is an integer constant, taken from the set of 8088** [SQLITE_DBSTATUS options], that 8089** determines the parameter to interrogate. The set of 8090** [SQLITE_DBSTATUS options] is likely 8091** to grow in future releases of SQLite. 8092** 8093** ^The current value of the requested parameter is written into *pCur 8094** and the highest instantaneous value is written into *pHiwtr. ^If 8095** the resetFlg is true, then the highest instantaneous value is 8096** reset back down to the current value. 8097** 8098** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8099** non-zero [error code] on failure. 8100** 8101** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8102*/ 8103SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8104 8105/* 8106** CAPI3REF: Status Parameters for database connections 8107** KEYWORDS: {SQLITE_DBSTATUS options} 8108** 8109** These constants are the available integer "verbs" that can be passed as 8110** the second argument to the [sqlite3_db_status()] interface. 8111** 8112** New verbs may be added in future releases of SQLite. Existing verbs 8113** might be discontinued. Applications should check the return code from 8114** [sqlite3_db_status()] to make sure that the call worked. 8115** The [sqlite3_db_status()] interface will return a non-zero error code 8116** if a discontinued or unsupported verb is invoked. 8117** 8118** <dl> 8119** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8120** <dd>This parameter returns the number of lookaside memory slots currently 8121** checked out.</dd>)^ 8122** 8123** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8124** <dd>This parameter returns the number of malloc attempts that were 8125** satisfied using lookaside memory. Only the high-water value is meaningful; 8126** the current value is always zero.)^ 8127** 8128** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8129** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8130** <dd>This parameter returns the number malloc attempts that might have 8131** been satisfied using lookaside memory but failed due to the amount of 8132** memory requested being larger than the lookaside slot size. 8133** Only the high-water value is meaningful; 8134** the current value is always zero.)^ 8135** 8136** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8137** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8138** <dd>This parameter returns the number malloc attempts that might have 8139** been satisfied using lookaside memory but failed due to all lookaside 8140** memory already being in use. 8141** Only the high-water value is meaningful; 8142** the current value is always zero.)^ 8143** 8144** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8145** <dd>This parameter returns the approximate number of bytes of heap 8146** memory used by all pager caches associated with the database connection.)^ 8147** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8148** 8149** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8150** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8151** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8152** pager cache is shared between two or more connections the bytes of heap 8153** memory used by that pager cache is divided evenly between the attached 8154** connections.)^ In other words, if none of the pager caches associated 8155** with the database connection are shared, this request returns the same 8156** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8157** shared, the value returned by this call will be smaller than that returned 8158** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8159** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8160** 8161** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8162** <dd>This parameter returns the approximate number of bytes of heap 8163** memory used to store the schema for all databases associated 8164** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8165** ^The full amount of memory used by the schemas is reported, even if the 8166** schema memory is shared with other database connections due to 8167** [shared cache mode] being enabled. 8168** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8169** 8170** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8171** <dd>This parameter returns the approximate number of bytes of heap 8172** and lookaside memory used by all prepared statements associated with 8173** the database connection.)^ 8174** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8175** </dd> 8176** 8177** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8178** <dd>This parameter returns the number of pager cache hits that have 8179** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8180** is always 0. 8181** </dd> 8182** 8183** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8184** <dd>This parameter returns the number of pager cache misses that have 8185** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8186** is always 0. 8187** </dd> 8188** 8189** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8190** <dd>This parameter returns the number of dirty cache entries that have 8191** been written to disk. Specifically, the number of pages written to the 8192** wal file in wal mode databases, or the number of pages written to the 8193** database file in rollback mode databases. Any pages written as part of 8194** transaction rollback or database recovery operations are not included. 8195** If an IO or other error occurs while writing a page to disk, the effect 8196** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8197** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8198** </dd> 8199** 8200** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8201** <dd>This parameter returns the number of dirty cache entries that have 8202** been written to disk in the middle of a transaction due to the page 8203** cache overflowing. Transactions are more efficient if they are written 8204** to disk all at once. When pages spill mid-transaction, that introduces 8205** additional overhead. This parameter can be used help identify 8206** inefficiencies that can be resolved by increasing the cache size. 8207** </dd> 8208** 8209** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8210** <dd>This parameter returns zero for the current value if and only if 8211** all foreign key constraints (deferred or immediate) have been 8212** resolved.)^ ^The highwater mark is always 0. 8213** </dd> 8214** </dl> 8215*/ 8216#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8217#define SQLITE_DBSTATUS_CACHE_USED 1 8218#define SQLITE_DBSTATUS_SCHEMA_USED 2 8219#define SQLITE_DBSTATUS_STMT_USED 3 8220#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8221#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8222#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8223#define SQLITE_DBSTATUS_CACHE_HIT 7 8224#define SQLITE_DBSTATUS_CACHE_MISS 8 8225#define SQLITE_DBSTATUS_CACHE_WRITE 9 8226#define SQLITE_DBSTATUS_DEFERRED_FKS 10 8227#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8228#define SQLITE_DBSTATUS_CACHE_SPILL 12 8229#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8230 8231 8232/* 8233** CAPI3REF: Prepared Statement Status 8234** METHOD: sqlite3_stmt 8235** 8236** ^(Each prepared statement maintains various 8237** [SQLITE_STMTSTATUS counters] that measure the number 8238** of times it has performed specific operations.)^ These counters can 8239** be used to monitor the performance characteristics of the prepared 8240** statements. For example, if the number of table steps greatly exceeds 8241** the number of table searches or result rows, that would tend to indicate 8242** that the prepared statement is using a full table scan rather than 8243** an index. 8244** 8245** ^(This interface is used to retrieve and reset counter values from 8246** a [prepared statement]. The first argument is the prepared statement 8247** object to be interrogated. The second argument 8248** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8249** to be interrogated.)^ 8250** ^The current value of the requested counter is returned. 8251** ^If the resetFlg is true, then the counter is reset to zero after this 8252** interface call returns. 8253** 8254** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8255*/ 8256SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8257 8258/* 8259** CAPI3REF: Status Parameters for prepared statements 8260** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8261** 8262** These preprocessor macros define integer codes that name counter 8263** values associated with the [sqlite3_stmt_status()] interface. 8264** The meanings of the various counters are as follows: 8265** 8266** <dl> 8267** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8268** <dd>^This is the number of times that SQLite has stepped forward in 8269** a table as part of a full table scan. Large numbers for this counter 8270** may indicate opportunities for performance improvement through 8271** careful use of indices.</dd> 8272** 8273** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8274** <dd>^This is the number of sort operations that have occurred. 8275** A non-zero value in this counter may indicate an opportunity to 8276** improvement performance through careful use of indices.</dd> 8277** 8278** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8279** <dd>^This is the number of rows inserted into transient indices that 8280** were created automatically in order to help joins run faster. 8281** A non-zero value in this counter may indicate an opportunity to 8282** improvement performance by adding permanent indices that do not 8283** need to be reinitialized each time the statement is run.</dd> 8284** 8285** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8286** <dd>^This is the number of virtual machine operations executed 8287** by the prepared statement if that number is less than or equal 8288** to 2147483647. The number of virtual machine operations can be 8289** used as a proxy for the total work done by the prepared statement. 8290** If the number of virtual machine operations exceeds 2147483647 8291** then the value returned by this statement status code is undefined. 8292** 8293** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8294** <dd>^This is the number of times that the prepare statement has been 8295** automatically regenerated due to schema changes or changes to 8296** [bound parameters] that might affect the query plan. 8297** 8298** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8299** <dd>^This is the number of times that the prepared statement has 8300** been run. A single "run" for the purposes of this counter is one 8301** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8302** The counter is incremented on the first [sqlite3_step()] call of each 8303** cycle. 8304** 8305** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8306** <dd>^This is the approximate number of bytes of heap memory 8307** used to store the prepared statement. ^This value is not actually 8308** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8309** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8310** </dd> 8311** </dl> 8312*/ 8313#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8314#define SQLITE_STMTSTATUS_SORT 2 8315#define SQLITE_STMTSTATUS_AUTOINDEX 3 8316#define SQLITE_STMTSTATUS_VM_STEP 4 8317#define SQLITE_STMTSTATUS_REPREPARE 5 8318#define SQLITE_STMTSTATUS_RUN 6 8319#define SQLITE_STMTSTATUS_MEMUSED 99 8320 8321/* 8322** CAPI3REF: Custom Page Cache Object 8323** 8324** The sqlite3_pcache type is opaque. It is implemented by 8325** the pluggable module. The SQLite core has no knowledge of 8326** its size or internal structure and never deals with the 8327** sqlite3_pcache object except by holding and passing pointers 8328** to the object. 8329** 8330** See [sqlite3_pcache_methods2] for additional information. 8331*/ 8332typedef struct sqlite3_pcache sqlite3_pcache; 8333 8334/* 8335** CAPI3REF: Custom Page Cache Object 8336** 8337** The sqlite3_pcache_page object represents a single page in the 8338** page cache. The page cache will allocate instances of this 8339** object. Various methods of the page cache use pointers to instances 8340** of this object as parameters or as their return value. 8341** 8342** See [sqlite3_pcache_methods2] for additional information. 8343*/ 8344typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8345struct sqlite3_pcache_page { 8346 void *pBuf; /* The content of the page */ 8347 void *pExtra; /* Extra information associated with the page */ 8348}; 8349 8350/* 8351** CAPI3REF: Application Defined Page Cache. 8352** KEYWORDS: {page cache} 8353** 8354** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8355** register an alternative page cache implementation by passing in an 8356** instance of the sqlite3_pcache_methods2 structure.)^ 8357** In many applications, most of the heap memory allocated by 8358** SQLite is used for the page cache. 8359** By implementing a 8360** custom page cache using this API, an application can better control 8361** the amount of memory consumed by SQLite, the way in which 8362** that memory is allocated and released, and the policies used to 8363** determine exactly which parts of a database file are cached and for 8364** how long. 8365** 8366** The alternative page cache mechanism is an 8367** extreme measure that is only needed by the most demanding applications. 8368** The built-in page cache is recommended for most uses. 8369** 8370** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8371** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8372** the application may discard the parameter after the call to 8373** [sqlite3_config()] returns.)^ 8374** 8375** [[the xInit() page cache method]] 8376** ^(The xInit() method is called once for each effective 8377** call to [sqlite3_initialize()])^ 8378** (usually only once during the lifetime of the process). ^(The xInit() 8379** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8380** The intent of the xInit() method is to set up global data structures 8381** required by the custom page cache implementation. 8382** ^(If the xInit() method is NULL, then the 8383** built-in default page cache is used instead of the application defined 8384** page cache.)^ 8385** 8386** [[the xShutdown() page cache method]] 8387** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8388** It can be used to clean up 8389** any outstanding resources before process shutdown, if required. 8390** ^The xShutdown() method may be NULL. 8391** 8392** ^SQLite automatically serializes calls to the xInit method, 8393** so the xInit method need not be threadsafe. ^The 8394** xShutdown method is only called from [sqlite3_shutdown()] so it does 8395** not need to be threadsafe either. All other methods must be threadsafe 8396** in multithreaded applications. 8397** 8398** ^SQLite will never invoke xInit() more than once without an intervening 8399** call to xShutdown(). 8400** 8401** [[the xCreate() page cache methods]] 8402** ^SQLite invokes the xCreate() method to construct a new cache instance. 8403** SQLite will typically create one cache instance for each open database file, 8404** though this is not guaranteed. ^The 8405** first parameter, szPage, is the size in bytes of the pages that must 8406** be allocated by the cache. ^szPage will always a power of two. ^The 8407** second parameter szExtra is a number of bytes of extra storage 8408** associated with each page cache entry. ^The szExtra parameter will 8409** a number less than 250. SQLite will use the 8410** extra szExtra bytes on each page to store metadata about the underlying 8411** database page on disk. The value passed into szExtra depends 8412** on the SQLite version, the target platform, and how SQLite was compiled. 8413** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8414** created will be used to cache database pages of a file stored on disk, or 8415** false if it is used for an in-memory database. The cache implementation 8416** does not have to do anything special based with the value of bPurgeable; 8417** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8418** never invoke xUnpin() except to deliberately delete a page. 8419** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8420** false will always have the "discard" flag set to true. 8421** ^Hence, a cache created with bPurgeable false will 8422** never contain any unpinned pages. 8423** 8424** [[the xCachesize() page cache method]] 8425** ^(The xCachesize() method may be called at any time by SQLite to set the 8426** suggested maximum cache-size (number of pages stored by) the cache 8427** instance passed as the first argument. This is the value configured using 8428** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8429** parameter, the implementation is not required to do anything with this 8430** value; it is advisory only. 8431** 8432** [[the xPagecount() page cache methods]] 8433** The xPagecount() method must return the number of pages currently 8434** stored in the cache, both pinned and unpinned. 8435** 8436** [[the xFetch() page cache methods]] 8437** The xFetch() method locates a page in the cache and returns a pointer to 8438** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8439** The pBuf element of the returned sqlite3_pcache_page object will be a 8440** pointer to a buffer of szPage bytes used to store the content of a 8441** single database page. The pExtra element of sqlite3_pcache_page will be 8442** a pointer to the szExtra bytes of extra storage that SQLite has requested 8443** for each entry in the page cache. 8444** 8445** The page to be fetched is determined by the key. ^The minimum key value 8446** is 1. After it has been retrieved using xFetch, the page is considered 8447** to be "pinned". 8448** 8449** If the requested page is already in the page cache, then the page cache 8450** implementation must return a pointer to the page buffer with its content 8451** intact. If the requested page is not already in the cache, then the 8452** cache implementation should use the value of the createFlag 8453** parameter to help it determined what action to take: 8454** 8455** <table border=1 width=85% align=center> 8456** <tr><th> createFlag <th> Behavior when page is not already in cache 8457** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8458** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8459** Otherwise return NULL. 8460** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8461** NULL if allocating a new page is effectively impossible. 8462** </table> 8463** 8464** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8465** will only use a createFlag of 2 after a prior call with a createFlag of 1 8466** failed.)^ In between the xFetch() calls, SQLite may 8467** attempt to unpin one or more cache pages by spilling the content of 8468** pinned pages to disk and synching the operating system disk cache. 8469** 8470** [[the xUnpin() page cache method]] 8471** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8472** as its second argument. If the third parameter, discard, is non-zero, 8473** then the page must be evicted from the cache. 8474** ^If the discard parameter is 8475** zero, then the page may be discarded or retained at the discretion of 8476** page cache implementation. ^The page cache implementation 8477** may choose to evict unpinned pages at any time. 8478** 8479** The cache must not perform any reference counting. A single 8480** call to xUnpin() unpins the page regardless of the number of prior calls 8481** to xFetch(). 8482** 8483** [[the xRekey() page cache methods]] 8484** The xRekey() method is used to change the key value associated with the 8485** page passed as the second argument. If the cache 8486** previously contains an entry associated with newKey, it must be 8487** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8488** to be pinned. 8489** 8490** When SQLite calls the xTruncate() method, the cache must discard all 8491** existing cache entries with page numbers (keys) greater than or equal 8492** to the value of the iLimit parameter passed to xTruncate(). If any 8493** of these pages are pinned, they are implicitly unpinned, meaning that 8494** they can be safely discarded. 8495** 8496** [[the xDestroy() page cache method]] 8497** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8498** All resources associated with the specified cache should be freed. ^After 8499** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8500** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8501** functions. 8502** 8503** [[the xShrink() page cache method]] 8504** ^SQLite invokes the xShrink() method when it wants the page cache to 8505** free up as much of heap memory as possible. The page cache implementation 8506** is not obligated to free any memory, but well-behaved implementations should 8507** do their best. 8508*/ 8509typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8510struct sqlite3_pcache_methods2 { 8511 int iVersion; 8512 void *pArg; 8513 int (*xInit)(void*); 8514 void (*xShutdown)(void*); 8515 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8516 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8517 int (*xPagecount)(sqlite3_pcache*); 8518 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8519 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8520 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8521 unsigned oldKey, unsigned newKey); 8522 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8523 void (*xDestroy)(sqlite3_pcache*); 8524 void (*xShrink)(sqlite3_pcache*); 8525}; 8526 8527/* 8528** This is the obsolete pcache_methods object that has now been replaced 8529** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8530** retained in the header file for backwards compatibility only. 8531*/ 8532typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8533struct sqlite3_pcache_methods { 8534 void *pArg; 8535 int (*xInit)(void*); 8536 void (*xShutdown)(void*); 8537 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8538 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8539 int (*xPagecount)(sqlite3_pcache*); 8540 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8541 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8542 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8543 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8544 void (*xDestroy)(sqlite3_pcache*); 8545}; 8546 8547 8548/* 8549** CAPI3REF: Online Backup Object 8550** 8551** The sqlite3_backup object records state information about an ongoing 8552** online backup operation. ^The sqlite3_backup object is created by 8553** a call to [sqlite3_backup_init()] and is destroyed by a call to 8554** [sqlite3_backup_finish()]. 8555** 8556** See Also: [Using the SQLite Online Backup API] 8557*/ 8558typedef struct sqlite3_backup sqlite3_backup; 8559 8560/* 8561** CAPI3REF: Online Backup API. 8562** 8563** The backup API copies the content of one database into another. 8564** It is useful either for creating backups of databases or 8565** for copying in-memory databases to or from persistent files. 8566** 8567** See Also: [Using the SQLite Online Backup API] 8568** 8569** ^SQLite holds a write transaction open on the destination database file 8570** for the duration of the backup operation. 8571** ^The source database is read-locked only while it is being read; 8572** it is not locked continuously for the entire backup operation. 8573** ^Thus, the backup may be performed on a live source database without 8574** preventing other database connections from 8575** reading or writing to the source database while the backup is underway. 8576** 8577** ^(To perform a backup operation: 8578** <ol> 8579** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8580** backup, 8581** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8582** the data between the two databases, and finally 8583** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8584** associated with the backup operation. 8585** </ol>)^ 8586** There should be exactly one call to sqlite3_backup_finish() for each 8587** successful call to sqlite3_backup_init(). 8588** 8589** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8590** 8591** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8592** [database connection] associated with the destination database 8593** and the database name, respectively. 8594** ^The database name is "main" for the main database, "temp" for the 8595** temporary database, or the name specified after the AS keyword in 8596** an [ATTACH] statement for an attached database. 8597** ^The S and M arguments passed to 8598** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8599** and database name of the source database, respectively. 8600** ^The source and destination [database connections] (parameters S and D) 8601** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8602** an error. 8603** 8604** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8605** there is already a read or read-write transaction open on the 8606** destination database. 8607** 8608** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8609** returned and an error code and error message are stored in the 8610** destination [database connection] D. 8611** ^The error code and message for the failed call to sqlite3_backup_init() 8612** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8613** [sqlite3_errmsg16()] functions. 8614** ^A successful call to sqlite3_backup_init() returns a pointer to an 8615** [sqlite3_backup] object. 8616** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8617** sqlite3_backup_finish() functions to perform the specified backup 8618** operation. 8619** 8620** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8621** 8622** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8623** the source and destination databases specified by [sqlite3_backup] object B. 8624** ^If N is negative, all remaining source pages are copied. 8625** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8626** are still more pages to be copied, then the function returns [SQLITE_OK]. 8627** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8628** from source to destination, then it returns [SQLITE_DONE]. 8629** ^If an error occurs while running sqlite3_backup_step(B,N), 8630** then an [error code] is returned. ^As well as [SQLITE_OK] and 8631** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8632** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8633** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8634** 8635** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8636** <ol> 8637** <li> the destination database was opened read-only, or 8638** <li> the destination database is using write-ahead-log journaling 8639** and the destination and source page sizes differ, or 8640** <li> the destination database is an in-memory database and the 8641** destination and source page sizes differ. 8642** </ol>)^ 8643** 8644** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8645** the [sqlite3_busy_handler | busy-handler function] 8646** is invoked (if one is specified). ^If the 8647** busy-handler returns non-zero before the lock is available, then 8648** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8649** sqlite3_backup_step() can be retried later. ^If the source 8650** [database connection] 8651** is being used to write to the source database when sqlite3_backup_step() 8652** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8653** case the call to sqlite3_backup_step() can be retried later on. ^(If 8654** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8655** [SQLITE_READONLY] is returned, then 8656** there is no point in retrying the call to sqlite3_backup_step(). These 8657** errors are considered fatal.)^ The application must accept 8658** that the backup operation has failed and pass the backup operation handle 8659** to the sqlite3_backup_finish() to release associated resources. 8660** 8661** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8662** on the destination file. ^The exclusive lock is not released until either 8663** sqlite3_backup_finish() is called or the backup operation is complete 8664** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8665** sqlite3_backup_step() obtains a [shared lock] on the source database that 8666** lasts for the duration of the sqlite3_backup_step() call. 8667** ^Because the source database is not locked between calls to 8668** sqlite3_backup_step(), the source database may be modified mid-way 8669** through the backup process. ^If the source database is modified by an 8670** external process or via a database connection other than the one being 8671** used by the backup operation, then the backup will be automatically 8672** restarted by the next call to sqlite3_backup_step(). ^If the source 8673** database is modified by the using the same database connection as is used 8674** by the backup operation, then the backup database is automatically 8675** updated at the same time. 8676** 8677** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8678** 8679** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8680** application wishes to abandon the backup operation, the application 8681** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8682** ^The sqlite3_backup_finish() interfaces releases all 8683** resources associated with the [sqlite3_backup] object. 8684** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8685** active write-transaction on the destination database is rolled back. 8686** The [sqlite3_backup] object is invalid 8687** and may not be used following a call to sqlite3_backup_finish(). 8688** 8689** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8690** sqlite3_backup_step() errors occurred, regardless or whether or not 8691** sqlite3_backup_step() completed. 8692** ^If an out-of-memory condition or IO error occurred during any prior 8693** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8694** sqlite3_backup_finish() returns the corresponding [error code]. 8695** 8696** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8697** is not a permanent error and does not affect the return value of 8698** sqlite3_backup_finish(). 8699** 8700** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8701** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8702** 8703** ^The sqlite3_backup_remaining() routine returns the number of pages still 8704** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8705** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8706** in the source database at the conclusion of the most recent 8707** sqlite3_backup_step(). 8708** ^(The values returned by these functions are only updated by 8709** sqlite3_backup_step(). If the source database is modified in a way that 8710** changes the size of the source database or the number of pages remaining, 8711** those changes are not reflected in the output of sqlite3_backup_pagecount() 8712** and sqlite3_backup_remaining() until after the next 8713** sqlite3_backup_step().)^ 8714** 8715** <b>Concurrent Usage of Database Handles</b> 8716** 8717** ^The source [database connection] may be used by the application for other 8718** purposes while a backup operation is underway or being initialized. 8719** ^If SQLite is compiled and configured to support threadsafe database 8720** connections, then the source database connection may be used concurrently 8721** from within other threads. 8722** 8723** However, the application must guarantee that the destination 8724** [database connection] is not passed to any other API (by any thread) after 8725** sqlite3_backup_init() is called and before the corresponding call to 8726** sqlite3_backup_finish(). SQLite does not currently check to see 8727** if the application incorrectly accesses the destination [database connection] 8728** and so no error code is reported, but the operations may malfunction 8729** nevertheless. Use of the destination database connection while a 8730** backup is in progress might also also cause a mutex deadlock. 8731** 8732** If running in [shared cache mode], the application must 8733** guarantee that the shared cache used by the destination database 8734** is not accessed while the backup is running. In practice this means 8735** that the application must guarantee that the disk file being 8736** backed up to is not accessed by any connection within the process, 8737** not just the specific connection that was passed to sqlite3_backup_init(). 8738** 8739** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8740** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8741** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8742** APIs are not strictly speaking threadsafe. If they are invoked at the 8743** same time as another thread is invoking sqlite3_backup_step() it is 8744** possible that they return invalid values. 8745*/ 8746SQLITE_API sqlite3_backup *sqlite3_backup_init( 8747 sqlite3 *pDest, /* Destination database handle */ 8748 const char *zDestName, /* Destination database name */ 8749 sqlite3 *pSource, /* Source database handle */ 8750 const char *zSourceName /* Source database name */ 8751); 8752SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8753SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8754SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8755SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8756 8757/* 8758** CAPI3REF: Unlock Notification 8759** METHOD: sqlite3 8760** 8761** ^When running in shared-cache mode, a database operation may fail with 8762** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8763** individual tables within the shared-cache cannot be obtained. See 8764** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8765** ^This API may be used to register a callback that SQLite will invoke 8766** when the connection currently holding the required lock relinquishes it. 8767** ^This API is only available if the library was compiled with the 8768** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8769** 8770** See Also: [Using the SQLite Unlock Notification Feature]. 8771** 8772** ^Shared-cache locks are released when a database connection concludes 8773** its current transaction, either by committing it or rolling it back. 8774** 8775** ^When a connection (known as the blocked connection) fails to obtain a 8776** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8777** identity of the database connection (the blocking connection) that 8778** has locked the required resource is stored internally. ^After an 8779** application receives an SQLITE_LOCKED error, it may call the 8780** sqlite3_unlock_notify() method with the blocked connection handle as 8781** the first argument to register for a callback that will be invoked 8782** when the blocking connections current transaction is concluded. ^The 8783** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8784** call that concludes the blocking connection's transaction. 8785** 8786** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8787** there is a chance that the blocking connection will have already 8788** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8789** If this happens, then the specified callback is invoked immediately, 8790** from within the call to sqlite3_unlock_notify().)^ 8791** 8792** ^If the blocked connection is attempting to obtain a write-lock on a 8793** shared-cache table, and more than one other connection currently holds 8794** a read-lock on the same table, then SQLite arbitrarily selects one of 8795** the other connections to use as the blocking connection. 8796** 8797** ^(There may be at most one unlock-notify callback registered by a 8798** blocked connection. If sqlite3_unlock_notify() is called when the 8799** blocked connection already has a registered unlock-notify callback, 8800** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8801** called with a NULL pointer as its second argument, then any existing 8802** unlock-notify callback is canceled. ^The blocked connections 8803** unlock-notify callback may also be canceled by closing the blocked 8804** connection using [sqlite3_close()]. 8805** 8806** The unlock-notify callback is not reentrant. If an application invokes 8807** any sqlite3_xxx API functions from within an unlock-notify callback, a 8808** crash or deadlock may be the result. 8809** 8810** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8811** returns SQLITE_OK. 8812** 8813** <b>Callback Invocation Details</b> 8814** 8815** When an unlock-notify callback is registered, the application provides a 8816** single void* pointer that is passed to the callback when it is invoked. 8817** However, the signature of the callback function allows SQLite to pass 8818** it an array of void* context pointers. The first argument passed to 8819** an unlock-notify callback is a pointer to an array of void* pointers, 8820** and the second is the number of entries in the array. 8821** 8822** When a blocking connection's transaction is concluded, there may be 8823** more than one blocked connection that has registered for an unlock-notify 8824** callback. ^If two or more such blocked connections have specified the 8825** same callback function, then instead of invoking the callback function 8826** multiple times, it is invoked once with the set of void* context pointers 8827** specified by the blocked connections bundled together into an array. 8828** This gives the application an opportunity to prioritize any actions 8829** related to the set of unblocked database connections. 8830** 8831** <b>Deadlock Detection</b> 8832** 8833** Assuming that after registering for an unlock-notify callback a 8834** database waits for the callback to be issued before taking any further 8835** action (a reasonable assumption), then using this API may cause the 8836** application to deadlock. For example, if connection X is waiting for 8837** connection Y's transaction to be concluded, and similarly connection 8838** Y is waiting on connection X's transaction, then neither connection 8839** will proceed and the system may remain deadlocked indefinitely. 8840** 8841** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8842** detection. ^If a given call to sqlite3_unlock_notify() would put the 8843** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8844** unlock-notify callback is registered. The system is said to be in 8845** a deadlocked state if connection A has registered for an unlock-notify 8846** callback on the conclusion of connection B's transaction, and connection 8847** B has itself registered for an unlock-notify callback when connection 8848** A's transaction is concluded. ^Indirect deadlock is also detected, so 8849** the system is also considered to be deadlocked if connection B has 8850** registered for an unlock-notify callback on the conclusion of connection 8851** C's transaction, where connection C is waiting on connection A. ^Any 8852** number of levels of indirection are allowed. 8853** 8854** <b>The "DROP TABLE" Exception</b> 8855** 8856** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8857** always appropriate to call sqlite3_unlock_notify(). There is however, 8858** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8859** SQLite checks if there are any currently executing SELECT statements 8860** that belong to the same connection. If there are, SQLITE_LOCKED is 8861** returned. In this case there is no "blocking connection", so invoking 8862** sqlite3_unlock_notify() results in the unlock-notify callback being 8863** invoked immediately. If the application then re-attempts the "DROP TABLE" 8864** or "DROP INDEX" query, an infinite loop might be the result. 8865** 8866** One way around this problem is to check the extended error code returned 8867** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8868** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8869** the special "DROP TABLE/INDEX" case, the extended error code is just 8870** SQLITE_LOCKED.)^ 8871*/ 8872SQLITE_API int sqlite3_unlock_notify( 8873 sqlite3 *pBlocked, /* Waiting connection */ 8874 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8875 void *pNotifyArg /* Argument to pass to xNotify */ 8876); 8877 8878 8879/* 8880** CAPI3REF: String Comparison 8881** 8882** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8883** and extensions to compare the contents of two buffers containing UTF-8 8884** strings in a case-independent fashion, using the same definition of "case 8885** independence" that SQLite uses internally when comparing identifiers. 8886*/ 8887SQLITE_API int sqlite3_stricmp(const char *, const char *); 8888SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8889 8890/* 8891** CAPI3REF: String Globbing 8892* 8893** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8894** string X matches the [GLOB] pattern P. 8895** ^The definition of [GLOB] pattern matching used in 8896** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8897** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8898** is case sensitive. 8899** 8900** Note that this routine returns zero on a match and non-zero if the strings 8901** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8902** 8903** See also: [sqlite3_strlike()]. 8904*/ 8905SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8906 8907/* 8908** CAPI3REF: String LIKE Matching 8909* 8910** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8911** string X matches the [LIKE] pattern P with escape character E. 8912** ^The definition of [LIKE] pattern matching used in 8913** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8914** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8915** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8916** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8917** insensitive - equivalent upper and lower case ASCII characters match 8918** one another. 8919** 8920** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8921** only ASCII characters are case folded. 8922** 8923** Note that this routine returns zero on a match and non-zero if the strings 8924** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8925** 8926** See also: [sqlite3_strglob()]. 8927*/ 8928SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8929 8930/* 8931** CAPI3REF: Error Logging Interface 8932** 8933** ^The [sqlite3_log()] interface writes a message into the [error log] 8934** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8935** ^If logging is enabled, the zFormat string and subsequent arguments are 8936** used with [sqlite3_snprintf()] to generate the final output string. 8937** 8938** The sqlite3_log() interface is intended for use by extensions such as 8939** virtual tables, collating functions, and SQL functions. While there is 8940** nothing to prevent an application from calling sqlite3_log(), doing so 8941** is considered bad form. 8942** 8943** The zFormat string must not be NULL. 8944** 8945** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8946** will not use dynamically allocated memory. The log message is stored in 8947** a fixed-length buffer on the stack. If the log message is longer than 8948** a few hundred characters, it will be truncated to the length of the 8949** buffer. 8950*/ 8951SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8952 8953/* 8954** CAPI3REF: Write-Ahead Log Commit Hook 8955** METHOD: sqlite3 8956** 8957** ^The [sqlite3_wal_hook()] function is used to register a callback that 8958** is invoked each time data is committed to a database in wal mode. 8959** 8960** ^(The callback is invoked by SQLite after the commit has taken place and 8961** the associated write-lock on the database released)^, so the implementation 8962** may read, write or [checkpoint] the database as required. 8963** 8964** ^The first parameter passed to the callback function when it is invoked 8965** is a copy of the third parameter passed to sqlite3_wal_hook() when 8966** registering the callback. ^The second is a copy of the database handle. 8967** ^The third parameter is the name of the database that was written to - 8968** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8969** is the number of pages currently in the write-ahead log file, 8970** including those that were just committed. 8971** 8972** The callback function should normally return [SQLITE_OK]. ^If an error 8973** code is returned, that error will propagate back up through the 8974** SQLite code base to cause the statement that provoked the callback 8975** to report an error, though the commit will have still occurred. If the 8976** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8977** that does not correspond to any valid SQLite error code, the results 8978** are undefined. 8979** 8980** A single database handle may have at most a single write-ahead log callback 8981** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8982** previously registered write-ahead log callback. ^Note that the 8983** [sqlite3_wal_autocheckpoint()] interface and the 8984** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8985** overwrite any prior [sqlite3_wal_hook()] settings. 8986*/ 8987SQLITE_API void *sqlite3_wal_hook( 8988 sqlite3*, 8989 int(*)(void *,sqlite3*,const char*,int), 8990 void* 8991); 8992 8993/* 8994** CAPI3REF: Configure an auto-checkpoint 8995** METHOD: sqlite3 8996** 8997** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8998** [sqlite3_wal_hook()] that causes any database on [database connection] D 8999** to automatically [checkpoint] 9000** after committing a transaction if there are N or 9001** more frames in the [write-ahead log] file. ^Passing zero or 9002** a negative value as the nFrame parameter disables automatic 9003** checkpoints entirely. 9004** 9005** ^The callback registered by this function replaces any existing callback 9006** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9007** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9008** configured by this function. 9009** 9010** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9011** from SQL. 9012** 9013** ^Checkpoints initiated by this mechanism are 9014** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9015** 9016** ^Every new [database connection] defaults to having the auto-checkpoint 9017** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9018** pages. The use of this interface 9019** is only necessary if the default setting is found to be suboptimal 9020** for a particular application. 9021*/ 9022SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9023 9024/* 9025** CAPI3REF: Checkpoint a database 9026** METHOD: sqlite3 9027** 9028** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9029** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9030** 9031** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9032** [write-ahead log] for database X on [database connection] D to be 9033** transferred into the database file and for the write-ahead log to 9034** be reset. See the [checkpointing] documentation for addition 9035** information. 9036** 9037** This interface used to be the only way to cause a checkpoint to 9038** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9039** interface was added. This interface is retained for backwards 9040** compatibility and as a convenience for applications that need to manually 9041** start a callback but which do not need the full power (and corresponding 9042** complication) of [sqlite3_wal_checkpoint_v2()]. 9043*/ 9044SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9045 9046/* 9047** CAPI3REF: Checkpoint a database 9048** METHOD: sqlite3 9049** 9050** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9051** operation on database X of [database connection] D in mode M. Status 9052** information is written back into integers pointed to by L and C.)^ 9053** ^(The M parameter must be a valid [checkpoint mode]:)^ 9054** 9055** <dl> 9056** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9057** ^Checkpoint as many frames as possible without waiting for any database 9058** readers or writers to finish, then sync the database file if all frames 9059** in the log were checkpointed. ^The [busy-handler callback] 9060** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9061** ^On the other hand, passive mode might leave the checkpoint unfinished 9062** if there are concurrent readers or writers. 9063** 9064** <dt>SQLITE_CHECKPOINT_FULL<dd> 9065** ^This mode blocks (it invokes the 9066** [sqlite3_busy_handler|busy-handler callback]) until there is no 9067** database writer and all readers are reading from the most recent database 9068** snapshot. ^It then checkpoints all frames in the log file and syncs the 9069** database file. ^This mode blocks new database writers while it is pending, 9070** but new database readers are allowed to continue unimpeded. 9071** 9072** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9073** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9074** that after checkpointing the log file it blocks (calls the 9075** [busy-handler callback]) 9076** until all readers are reading from the database file only. ^This ensures 9077** that the next writer will restart the log file from the beginning. 9078** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9079** database writer attempts while it is pending, but does not impede readers. 9080** 9081** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9082** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9083** addition that it also truncates the log file to zero bytes just prior 9084** to a successful return. 9085** </dl> 9086** 9087** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9088** the log file or to -1 if the checkpoint could not run because 9089** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9090** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9091** log file (including any that were already checkpointed before the function 9092** was called) or to -1 if the checkpoint could not run due to an error or 9093** because the database is not in WAL mode. ^Note that upon successful 9094** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9095** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9096** 9097** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9098** any other process is running a checkpoint operation at the same time, the 9099** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9100** busy-handler configured, it will not be invoked in this case. 9101** 9102** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9103** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9104** obtained immediately, and a busy-handler is configured, it is invoked and 9105** the writer lock retried until either the busy-handler returns 0 or the lock 9106** is successfully obtained. ^The busy-handler is also invoked while waiting for 9107** database readers as described above. ^If the busy-handler returns 0 before 9108** the writer lock is obtained or while waiting for database readers, the 9109** checkpoint operation proceeds from that point in the same way as 9110** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9111** without blocking any further. ^SQLITE_BUSY is returned in this case. 9112** 9113** ^If parameter zDb is NULL or points to a zero length string, then the 9114** specified operation is attempted on all WAL databases [attached] to 9115** [database connection] db. In this case the 9116** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9117** an SQLITE_BUSY error is encountered when processing one or more of the 9118** attached WAL databases, the operation is still attempted on any remaining 9119** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9120** error occurs while processing an attached database, processing is abandoned 9121** and the error code is returned to the caller immediately. ^If no error 9122** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9123** databases, SQLITE_OK is returned. 9124** 9125** ^If database zDb is the name of an attached database that is not in WAL 9126** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9127** zDb is not NULL (or a zero length string) and is not the name of any 9128** attached database, SQLITE_ERROR is returned to the caller. 9129** 9130** ^Unless it returns SQLITE_MISUSE, 9131** the sqlite3_wal_checkpoint_v2() interface 9132** sets the error information that is queried by 9133** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9134** 9135** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9136** from SQL. 9137*/ 9138SQLITE_API int sqlite3_wal_checkpoint_v2( 9139 sqlite3 *db, /* Database handle */ 9140 const char *zDb, /* Name of attached database (or NULL) */ 9141 int eMode, /* SQLITE_CHECKPOINT_* value */ 9142 int *pnLog, /* OUT: Size of WAL log in frames */ 9143 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9144); 9145 9146/* 9147** CAPI3REF: Checkpoint Mode Values 9148** KEYWORDS: {checkpoint mode} 9149** 9150** These constants define all valid values for the "checkpoint mode" passed 9151** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9152** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9153** meaning of each of these checkpoint modes. 9154*/ 9155#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9156#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9157#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9158#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9159 9160/* 9161** CAPI3REF: Virtual Table Interface Configuration 9162** 9163** This function may be called by either the [xConnect] or [xCreate] method 9164** of a [virtual table] implementation to configure 9165** various facets of the virtual table interface. 9166** 9167** If this interface is invoked outside the context of an xConnect or 9168** xCreate virtual table method then the behavior is undefined. 9169** 9170** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9171** [database connection] in which the virtual table is being created and 9172** which is passed in as the first argument to the [xConnect] or [xCreate] 9173** method that is invoking sqlite3_vtab_config(). The C parameter is one 9174** of the [virtual table configuration options]. The presence and meaning 9175** of parameters after C depend on which [virtual table configuration option] 9176** is used. 9177*/ 9178SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9179 9180/* 9181** CAPI3REF: Virtual Table Configuration Options 9182** KEYWORDS: {virtual table configuration options} 9183** KEYWORDS: {virtual table configuration option} 9184** 9185** These macros define the various options to the 9186** [sqlite3_vtab_config()] interface that [virtual table] implementations 9187** can use to customize and optimize their behavior. 9188** 9189** <dl> 9190** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9191** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9192** <dd>Calls of the form 9193** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9194** where X is an integer. If X is zero, then the [virtual table] whose 9195** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9196** support constraints. In this configuration (which is the default) if 9197** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9198** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9199** specified as part of the users SQL statement, regardless of the actual 9200** ON CONFLICT mode specified. 9201** 9202** If X is non-zero, then the virtual table implementation guarantees 9203** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9204** any modifications to internal or persistent data structures have been made. 9205** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9206** is able to roll back a statement or database transaction, and abandon 9207** or continue processing the current SQL statement as appropriate. 9208** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9209** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9210** had been ABORT. 9211** 9212** Virtual table implementations that are required to handle OR REPLACE 9213** must do so within the [xUpdate] method. If a call to the 9214** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9215** CONFLICT policy is REPLACE, the virtual table implementation should 9216** silently replace the appropriate rows within the xUpdate callback and 9217** return SQLITE_OK. Or, if this is not possible, it may return 9218** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9219** constraint handling. 9220** </dd> 9221** 9222** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9223** <dd>Calls of the form 9224** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9225** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9226** prohibits that virtual table from being used from within triggers and 9227** views. 9228** </dd> 9229** 9230** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9231** <dd>Calls of the form 9232** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9233** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9234** identify that virtual table as being safe to use from within triggers 9235** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9236** virtual table can do no serious harm even if it is controlled by a 9237** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9238** flag unless absolutely necessary. 9239** </dd> 9240** </dl> 9241*/ 9242#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9243#define SQLITE_VTAB_INNOCUOUS 2 9244#define SQLITE_VTAB_DIRECTONLY 3 9245 9246/* 9247** CAPI3REF: Determine The Virtual Table Conflict Policy 9248** 9249** This function may only be called from within a call to the [xUpdate] method 9250** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9251** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9252** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9253** of the SQL statement that triggered the call to the [xUpdate] method of the 9254** [virtual table]. 9255*/ 9256SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9257 9258/* 9259** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9260** 9261** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9262** method of a [virtual table], then it might return true if the 9263** column is being fetched as part of an UPDATE operation during which the 9264** column value will not change. The virtual table implementation can use 9265** this hint as permission to substitute a return value that is less 9266** expensive to compute and that the corresponding 9267** [xUpdate] method understands as a "no-change" value. 9268** 9269** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9270** the column is not changed by the UPDATE statement, then the xColumn 9271** method can optionally return without setting a result, without calling 9272** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9273** In that case, [sqlite3_value_nochange(X)] will return true for the 9274** same column in the [xUpdate] method. 9275** 9276** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9277** implementations should continue to give a correct answer even if the 9278** sqlite3_vtab_nochange() interface were to always return false. In the 9279** current implementation, the sqlite3_vtab_nochange() interface does always 9280** returns false for the enhanced [UPDATE FROM] statement. 9281*/ 9282SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9283 9284/* 9285** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9286** 9287** This function may only be called from within a call to the [xBestIndex] 9288** method of a [virtual table]. 9289** 9290** The first argument must be the sqlite3_index_info object that is the 9291** first parameter to the xBestIndex() method. The second argument must be 9292** an index into the aConstraint[] array belonging to the sqlite3_index_info 9293** structure passed to xBestIndex. This function returns a pointer to a buffer 9294** containing the name of the collation sequence for the corresponding 9295** constraint. 9296*/ 9297SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9298 9299/* 9300** CAPI3REF: Conflict resolution modes 9301** KEYWORDS: {conflict resolution mode} 9302** 9303** These constants are returned by [sqlite3_vtab_on_conflict()] to 9304** inform a [virtual table] implementation what the [ON CONFLICT] mode 9305** is for the SQL statement being evaluated. 9306** 9307** Note that the [SQLITE_IGNORE] constant is also used as a potential 9308** return value from the [sqlite3_set_authorizer()] callback and that 9309** [SQLITE_ABORT] is also a [result code]. 9310*/ 9311#define SQLITE_ROLLBACK 1 9312/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9313#define SQLITE_FAIL 3 9314/* #define SQLITE_ABORT 4 // Also an error code */ 9315#define SQLITE_REPLACE 5 9316 9317/* 9318** CAPI3REF: Prepared Statement Scan Status Opcodes 9319** KEYWORDS: {scanstatus options} 9320** 9321** The following constants can be used for the T parameter to the 9322** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9323** different metric for sqlite3_stmt_scanstatus() to return. 9324** 9325** When the value returned to V is a string, space to hold that string is 9326** managed by the prepared statement S and will be automatically freed when 9327** S is finalized. 9328** 9329** <dl> 9330** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9331** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9332** set to the total number of times that the X-th loop has run.</dd> 9333** 9334** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9335** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9336** to the total number of rows examined by all iterations of the X-th loop.</dd> 9337** 9338** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9339** <dd>^The "double" variable pointed to by the V parameter will be set to the 9340** query planner's estimate for the average number of rows output from each 9341** iteration of the X-th loop. If the query planner's estimates was accurate, 9342** then this value will approximate the quotient NVISIT/NLOOP and the 9343** product of this value for all prior loops with the same SELECTID will 9344** be the NLOOP value for the current loop. 9345** 9346** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9347** <dd>^The "const char *" variable pointed to by the V parameter will be set 9348** to a zero-terminated UTF-8 string containing the name of the index or table 9349** used for the X-th loop. 9350** 9351** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9352** <dd>^The "const char *" variable pointed to by the V parameter will be set 9353** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9354** description for the X-th loop. 9355** 9356** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9357** <dd>^The "int" variable pointed to by the V parameter will be set to the 9358** "select-id" for the X-th loop. The select-id identifies which query or 9359** subquery the loop is part of. The main query has a select-id of zero. 9360** The select-id is the same value as is output in the first column 9361** of an [EXPLAIN QUERY PLAN] query. 9362** </dl> 9363*/ 9364#define SQLITE_SCANSTAT_NLOOP 0 9365#define SQLITE_SCANSTAT_NVISIT 1 9366#define SQLITE_SCANSTAT_EST 2 9367#define SQLITE_SCANSTAT_NAME 3 9368#define SQLITE_SCANSTAT_EXPLAIN 4 9369#define SQLITE_SCANSTAT_SELECTID 5 9370 9371/* 9372** CAPI3REF: Prepared Statement Scan Status 9373** METHOD: sqlite3_stmt 9374** 9375** This interface returns information about the predicted and measured 9376** performance for pStmt. Advanced applications can use this 9377** interface to compare the predicted and the measured performance and 9378** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9379** 9380** Since this interface is expected to be rarely used, it is only 9381** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9382** compile-time option. 9383** 9384** The "iScanStatusOp" parameter determines which status information to return. 9385** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9386** of this interface is undefined. 9387** ^The requested measurement is written into a variable pointed to by 9388** the "pOut" parameter. 9389** Parameter "idx" identifies the specific loop to retrieve statistics for. 9390** Loops are numbered starting from zero. ^If idx is out of range - less than 9391** zero or greater than or equal to the total number of loops used to implement 9392** the statement - a non-zero value is returned and the variable that pOut 9393** points to is unchanged. 9394** 9395** ^Statistics might not be available for all loops in all statements. ^In cases 9396** where there exist loops with no available statistics, this function behaves 9397** as if the loop did not exist - it returns non-zero and leave the variable 9398** that pOut points to unchanged. 9399** 9400** See also: [sqlite3_stmt_scanstatus_reset()] 9401*/ 9402SQLITE_API int sqlite3_stmt_scanstatus( 9403 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9404 int idx, /* Index of loop to report on */ 9405 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9406 void *pOut /* Result written here */ 9407); 9408 9409/* 9410** CAPI3REF: Zero Scan-Status Counters 9411** METHOD: sqlite3_stmt 9412** 9413** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9414** 9415** This API is only available if the library is built with pre-processor 9416** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9417*/ 9418SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9419 9420/* 9421** CAPI3REF: Flush caches to disk mid-transaction 9422** METHOD: sqlite3 9423** 9424** ^If a write-transaction is open on [database connection] D when the 9425** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9426** pages in the pager-cache that are not currently in use are written out 9427** to disk. A dirty page may be in use if a database cursor created by an 9428** active SQL statement is reading from it, or if it is page 1 of a database 9429** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9430** interface flushes caches for all schemas - "main", "temp", and 9431** any [attached] databases. 9432** 9433** ^If this function needs to obtain extra database locks before dirty pages 9434** can be flushed to disk, it does so. ^If those locks cannot be obtained 9435** immediately and there is a busy-handler callback configured, it is invoked 9436** in the usual manner. ^If the required lock still cannot be obtained, then 9437** the database is skipped and an attempt made to flush any dirty pages 9438** belonging to the next (if any) database. ^If any databases are skipped 9439** because locks cannot be obtained, but no other error occurs, this 9440** function returns SQLITE_BUSY. 9441** 9442** ^If any other error occurs while flushing dirty pages to disk (for 9443** example an IO error or out-of-memory condition), then processing is 9444** abandoned and an SQLite [error code] is returned to the caller immediately. 9445** 9446** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9447** 9448** ^This function does not set the database handle error code or message 9449** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9450*/ 9451SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 9452 9453/* 9454** CAPI3REF: The pre-update hook. 9455** METHOD: sqlite3 9456** 9457** ^These interfaces are only available if SQLite is compiled using the 9458** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9459** 9460** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9461** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9462** on a database table. 9463** ^At most one preupdate hook may be registered at a time on a single 9464** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9465** the previous setting. 9466** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9467** with a NULL pointer as the second parameter. 9468** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9469** the first parameter to callbacks. 9470** 9471** ^The preupdate hook only fires for changes to real database tables; the 9472** preupdate hook is not invoked for changes to [virtual tables] or to 9473** system tables like sqlite_sequence or sqlite_stat1. 9474** 9475** ^The second parameter to the preupdate callback is a pointer to 9476** the [database connection] that registered the preupdate hook. 9477** ^The third parameter to the preupdate callback is one of the constants 9478** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9479** kind of update operation that is about to occur. 9480** ^(The fourth parameter to the preupdate callback is the name of the 9481** database within the database connection that is being modified. This 9482** will be "main" for the main database or "temp" for TEMP tables or 9483** the name given after the AS keyword in the [ATTACH] statement for attached 9484** databases.)^ 9485** ^The fifth parameter to the preupdate callback is the name of the 9486** table that is being modified. 9487** 9488** For an UPDATE or DELETE operation on a [rowid table], the sixth 9489** parameter passed to the preupdate callback is the initial [rowid] of the 9490** row being modified or deleted. For an INSERT operation on a rowid table, 9491** or any operation on a WITHOUT ROWID table, the value of the sixth 9492** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9493** seventh parameter is the final rowid value of the row being inserted 9494** or updated. The value of the seventh parameter passed to the callback 9495** function is not defined for operations on WITHOUT ROWID tables, or for 9496** DELETE operations on rowid tables. 9497** 9498** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9499** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9500** provide additional information about a preupdate event. These routines 9501** may only be called from within a preupdate callback. Invoking any of 9502** these routines from outside of a preupdate callback or with a 9503** [database connection] pointer that is different from the one supplied 9504** to the preupdate callback results in undefined and probably undesirable 9505** behavior. 9506** 9507** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9508** in the row that is being inserted, updated, or deleted. 9509** 9510** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9511** a [protected sqlite3_value] that contains the value of the Nth column of 9512** the table row before it is updated. The N parameter must be between 0 9513** and one less than the number of columns or the behavior will be 9514** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9515** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9516** behavior is undefined. The [sqlite3_value] that P points to 9517** will be destroyed when the preupdate callback returns. 9518** 9519** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9520** a [protected sqlite3_value] that contains the value of the Nth column of 9521** the table row after it is updated. The N parameter must be between 0 9522** and one less than the number of columns or the behavior will be 9523** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9524** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9525** behavior is undefined. The [sqlite3_value] that P points to 9526** will be destroyed when the preupdate callback returns. 9527** 9528** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9529** callback was invoked as a result of a direct insert, update, or delete 9530** operation; or 1 for inserts, updates, or deletes invoked by top-level 9531** triggers; or 2 for changes resulting from triggers called by top-level 9532** triggers; and so forth. 9533** 9534** See also: [sqlite3_update_hook()] 9535*/ 9536#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9537SQLITE_API void *sqlite3_preupdate_hook( 9538 sqlite3 *db, 9539 void(*xPreUpdate)( 9540 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9541 sqlite3 *db, /* Database handle */ 9542 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9543 char const *zDb, /* Database name */ 9544 char const *zName, /* Table name */ 9545 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9546 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9547 ), 9548 void* 9549); 9550SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9551SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 9552SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 9553SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9554#endif 9555 9556/* 9557** CAPI3REF: Low-level system error code 9558** METHOD: sqlite3 9559** 9560** ^Attempt to return the underlying operating system error code or error 9561** number that caused the most recent I/O error or failure to open a file. 9562** The return value is OS-dependent. For example, on unix systems, after 9563** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9564** called to get back the underlying "errno" that caused the problem, such 9565** as ENOSPC, EAUTH, EISDIR, and so forth. 9566*/ 9567SQLITE_API int sqlite3_system_errno(sqlite3*); 9568 9569/* 9570** CAPI3REF: Database Snapshot 9571** KEYWORDS: {snapshot} {sqlite3_snapshot} 9572** 9573** An instance of the snapshot object records the state of a [WAL mode] 9574** database for some specific point in history. 9575** 9576** In [WAL mode], multiple [database connections] that are open on the 9577** same database file can each be reading a different historical version 9578** of the database file. When a [database connection] begins a read 9579** transaction, that connection sees an unchanging copy of the database 9580** as it existed for the point in time when the transaction first started. 9581** Subsequent changes to the database from other connections are not seen 9582** by the reader until a new read transaction is started. 9583** 9584** The sqlite3_snapshot object records state information about an historical 9585** version of the database file so that it is possible to later open a new read 9586** transaction that sees that historical version of the database rather than 9587** the most recent version. 9588*/ 9589typedef struct sqlite3_snapshot { 9590 unsigned char hidden[48]; 9591} sqlite3_snapshot; 9592 9593/* 9594** CAPI3REF: Record A Database Snapshot 9595** CONSTRUCTOR: sqlite3_snapshot 9596** 9597** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9598** new [sqlite3_snapshot] object that records the current state of 9599** schema S in database connection D. ^On success, the 9600** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9601** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9602** If there is not already a read-transaction open on schema S when 9603** this function is called, one is opened automatically. 9604** 9605** The following must be true for this function to succeed. If any of 9606** the following statements are false when sqlite3_snapshot_get() is 9607** called, SQLITE_ERROR is returned. The final value of *P is undefined 9608** in this case. 9609** 9610** <ul> 9611** <li> The database handle must not be in [autocommit mode]. 9612** 9613** <li> Schema S of [database connection] D must be a [WAL mode] database. 9614** 9615** <li> There must not be a write transaction open on schema S of database 9616** connection D. 9617** 9618** <li> One or more transactions must have been written to the current wal 9619** file since it was created on disk (by any connection). This means 9620** that a snapshot cannot be taken on a wal mode database with no wal 9621** file immediately after it is first opened. At least one transaction 9622** must be written to it first. 9623** </ul> 9624** 9625** This function may also return SQLITE_NOMEM. If it is called with the 9626** database handle in autocommit mode but fails for some other reason, 9627** whether or not a read transaction is opened on schema S is undefined. 9628** 9629** The [sqlite3_snapshot] object returned from a successful call to 9630** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9631** to avoid a memory leak. 9632** 9633** The [sqlite3_snapshot_get()] interface is only available when the 9634** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9635*/ 9636SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9637 sqlite3 *db, 9638 const char *zSchema, 9639 sqlite3_snapshot **ppSnapshot 9640); 9641 9642/* 9643** CAPI3REF: Start a read transaction on an historical snapshot 9644** METHOD: sqlite3_snapshot 9645** 9646** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9647** transaction or upgrades an existing one for schema S of 9648** [database connection] D such that the read transaction refers to 9649** historical [snapshot] P, rather than the most recent change to the 9650** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9651** on success or an appropriate [error code] if it fails. 9652** 9653** ^In order to succeed, the database connection must not be in 9654** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9655** is already a read transaction open on schema S, then the database handle 9656** must have no active statements (SELECT statements that have been passed 9657** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9658** SQLITE_ERROR is returned if either of these conditions is violated, or 9659** if schema S does not exist, or if the snapshot object is invalid. 9660** 9661** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9662** snapshot has been overwritten by a [checkpoint]. In this case 9663** SQLITE_ERROR_SNAPSHOT is returned. 9664** 9665** If there is already a read transaction open when this function is 9666** invoked, then the same read transaction remains open (on the same 9667** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9668** is returned. If another error code - for example SQLITE_PROTOCOL or an 9669** SQLITE_IOERR error code - is returned, then the final state of the 9670** read transaction is undefined. If SQLITE_OK is returned, then the 9671** read transaction is now open on database snapshot P. 9672** 9673** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9674** database connection D does not know that the database file for 9675** schema S is in [WAL mode]. A database connection might not know 9676** that the database file is in [WAL mode] if there has been no prior 9677** I/O on that database connection, or if the database entered [WAL mode] 9678** after the most recent I/O on the database connection.)^ 9679** (Hint: Run "[PRAGMA application_id]" against a newly opened 9680** database connection in order to make it ready to use snapshots.) 9681** 9682** The [sqlite3_snapshot_open()] interface is only available when the 9683** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9684*/ 9685SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9686 sqlite3 *db, 9687 const char *zSchema, 9688 sqlite3_snapshot *pSnapshot 9689); 9690 9691/* 9692** CAPI3REF: Destroy a snapshot 9693** DESTRUCTOR: sqlite3_snapshot 9694** 9695** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9696** The application must eventually free every [sqlite3_snapshot] object 9697** using this routine to avoid a memory leak. 9698** 9699** The [sqlite3_snapshot_free()] interface is only available when the 9700** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9701*/ 9702SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9703 9704/* 9705** CAPI3REF: Compare the ages of two snapshot handles. 9706** METHOD: sqlite3_snapshot 9707** 9708** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9709** of two valid snapshot handles. 9710** 9711** If the two snapshot handles are not associated with the same database 9712** file, the result of the comparison is undefined. 9713** 9714** Additionally, the result of the comparison is only valid if both of the 9715** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9716** last time the wal file was deleted. The wal file is deleted when the 9717** database is changed back to rollback mode or when the number of database 9718** clients drops to zero. If either snapshot handle was obtained before the 9719** wal file was last deleted, the value returned by this function 9720** is undefined. 9721** 9722** Otherwise, this API returns a negative value if P1 refers to an older 9723** snapshot than P2, zero if the two handles refer to the same database 9724** snapshot, and a positive value if P1 is a newer snapshot than P2. 9725** 9726** This interface is only available if SQLite is compiled with the 9727** [SQLITE_ENABLE_SNAPSHOT] option. 9728*/ 9729SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9730 sqlite3_snapshot *p1, 9731 sqlite3_snapshot *p2 9732); 9733 9734/* 9735** CAPI3REF: Recover snapshots from a wal file 9736** METHOD: sqlite3_snapshot 9737** 9738** If a [WAL file] remains on disk after all database connections close 9739** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9740** or because the last process to have the database opened exited without 9741** calling [sqlite3_close()]) and a new connection is subsequently opened 9742** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9743** will only be able to open the last transaction added to the WAL file 9744** even though the WAL file contains other valid transactions. 9745** 9746** This function attempts to scan the WAL file associated with database zDb 9747** of database handle db and make all valid snapshots available to 9748** sqlite3_snapshot_open(). It is an error if there is already a read 9749** transaction open on the database, or if the database is not a WAL mode 9750** database. 9751** 9752** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9753** 9754** This interface is only available if SQLite is compiled with the 9755** [SQLITE_ENABLE_SNAPSHOT] option. 9756*/ 9757SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9758 9759/* 9760** CAPI3REF: Serialize a database 9761** 9762** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9763** that is a serialization of the S database on [database connection] D. 9764** If P is not a NULL pointer, then the size of the database in bytes 9765** is written into *P. 9766** 9767** For an ordinary on-disk database file, the serialization is just a 9768** copy of the disk file. For an in-memory database or a "TEMP" database, 9769** the serialization is the same sequence of bytes which would be written 9770** to disk if that database where backed up to disk. 9771** 9772** The usual case is that sqlite3_serialize() copies the serialization of 9773** the database into memory obtained from [sqlite3_malloc64()] and returns 9774** a pointer to that memory. The caller is responsible for freeing the 9775** returned value to avoid a memory leak. However, if the F argument 9776** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9777** are made, and the sqlite3_serialize() function will return a pointer 9778** to the contiguous memory representation of the database that SQLite 9779** is currently using for that database, or NULL if the no such contiguous 9780** memory representation of the database exists. A contiguous memory 9781** representation of the database will usually only exist if there has 9782** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9783** values of D and S. 9784** The size of the database is written into *P even if the 9785** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9786** of the database exists. 9787** 9788** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9789** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9790** allocation error occurs. 9791** 9792** This interface is only available if SQLite is compiled with the 9793** [SQLITE_ENABLE_DESERIALIZE] option. 9794*/ 9795SQLITE_API unsigned char *sqlite3_serialize( 9796 sqlite3 *db, /* The database connection */ 9797 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9798 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9799 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9800); 9801 9802/* 9803** CAPI3REF: Flags for sqlite3_serialize 9804** 9805** Zero or more of the following constants can be OR-ed together for 9806** the F argument to [sqlite3_serialize(D,S,P,F)]. 9807** 9808** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9809** a pointer to contiguous in-memory database that it is currently using, 9810** without making a copy of the database. If SQLite is not currently using 9811** a contiguous in-memory database, then this option causes 9812** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9813** using a contiguous in-memory database if it has been initialized by a 9814** prior call to [sqlite3_deserialize()]. 9815*/ 9816#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9817 9818/* 9819** CAPI3REF: Deserialize a database 9820** 9821** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9822** [database connection] D to disconnect from database S and then 9823** reopen S as an in-memory database based on the serialization contained 9824** in P. The serialized database P is N bytes in size. M is the size of 9825** the buffer P, which might be larger than N. If M is larger than N, and 9826** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9827** permitted to add content to the in-memory database as long as the total 9828** size does not exceed M bytes. 9829** 9830** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9831** invoke sqlite3_free() on the serialization buffer when the database 9832** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9833** SQLite will try to increase the buffer size using sqlite3_realloc64() 9834** if writes on the database cause it to grow larger than M bytes. 9835** 9836** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9837** database is currently in a read transaction or is involved in a backup 9838** operation. 9839** 9840** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9841** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9842** [sqlite3_free()] is invoked on argument P prior to returning. 9843** 9844** This interface is only available if SQLite is compiled with the 9845** [SQLITE_ENABLE_DESERIALIZE] option. 9846*/ 9847SQLITE_API int sqlite3_deserialize( 9848 sqlite3 *db, /* The database connection */ 9849 const char *zSchema, /* Which DB to reopen with the deserialization */ 9850 unsigned char *pData, /* The serialized database content */ 9851 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9852 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9853 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9854); 9855 9856/* 9857** CAPI3REF: Flags for sqlite3_deserialize() 9858** 9859** The following are allowed values for 6th argument (the F argument) to 9860** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9861** 9862** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9863** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9864** and that SQLite should take ownership of this memory and automatically 9865** free it when it has finished using it. Without this flag, the caller 9866** is responsible for freeing any dynamically allocated memory. 9867** 9868** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9869** grow the size of the database using calls to [sqlite3_realloc64()]. This 9870** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9871** Without this flag, the deserialized database cannot increase in size beyond 9872** the number of bytes specified by the M parameter. 9873** 9874** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9875** should be treated as read-only. 9876*/ 9877#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9878#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9879#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9880 9881/* 9882** Undo the hack that converts floating point types to integer for 9883** builds on processors without floating point support. 9884*/ 9885#ifdef SQLITE_OMIT_FLOATING_POINT 9886# undef double 9887#endif 9888 9889#ifdef __cplusplus 9890} /* End of the 'extern "C"' block */ 9891#endif 9892#endif /* SQLITE3_H */ 9893 9894/******** Begin file sqlite3rtree.h *********/ 9895/* 9896** 2010 August 30 9897** 9898** The author disclaims copyright to this source code. In place of 9899** a legal notice, here is a blessing: 9900** 9901** May you do good and not evil. 9902** May you find forgiveness for yourself and forgive others. 9903** May you share freely, never taking more than you give. 9904** 9905************************************************************************* 9906*/ 9907 9908#ifndef _SQLITE3RTREE_H_ 9909#define _SQLITE3RTREE_H_ 9910 9911 9912#ifdef __cplusplus 9913extern "C" { 9914#endif 9915 9916typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9917typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9918 9919/* The double-precision datatype used by RTree depends on the 9920** SQLITE_RTREE_INT_ONLY compile-time option. 9921*/ 9922#ifdef SQLITE_RTREE_INT_ONLY 9923 typedef sqlite3_int64 sqlite3_rtree_dbl; 9924#else 9925 typedef double sqlite3_rtree_dbl; 9926#endif 9927 9928/* 9929** Register a geometry callback named zGeom that can be used as part of an 9930** R-Tree geometry query as follows: 9931** 9932** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9933*/ 9934SQLITE_API int sqlite3_rtree_geometry_callback( 9935 sqlite3 *db, 9936 const char *zGeom, 9937 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9938 void *pContext 9939); 9940 9941 9942/* 9943** A pointer to a structure of the following type is passed as the first 9944** argument to callbacks registered using rtree_geometry_callback(). 9945*/ 9946struct sqlite3_rtree_geometry { 9947 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9948 int nParam; /* Size of array aParam[] */ 9949 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9950 void *pUser; /* Callback implementation user data */ 9951 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9952}; 9953 9954/* 9955** Register a 2nd-generation geometry callback named zScore that can be 9956** used as part of an R-Tree geometry query as follows: 9957** 9958** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9959*/ 9960SQLITE_API int sqlite3_rtree_query_callback( 9961 sqlite3 *db, 9962 const char *zQueryFunc, 9963 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9964 void *pContext, 9965 void (*xDestructor)(void*) 9966); 9967 9968 9969/* 9970** A pointer to a structure of the following type is passed as the 9971** argument to scored geometry callback registered using 9972** sqlite3_rtree_query_callback(). 9973** 9974** Note that the first 5 fields of this structure are identical to 9975** sqlite3_rtree_geometry. This structure is a subclass of 9976** sqlite3_rtree_geometry. 9977*/ 9978struct sqlite3_rtree_query_info { 9979 void *pContext; /* pContext from when function registered */ 9980 int nParam; /* Number of function parameters */ 9981 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9982 void *pUser; /* callback can use this, if desired */ 9983 void (*xDelUser)(void*); /* function to free pUser */ 9984 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9985 unsigned int *anQueue; /* Number of pending entries in the queue */ 9986 int nCoord; /* Number of coordinates */ 9987 int iLevel; /* Level of current node or entry */ 9988 int mxLevel; /* The largest iLevel value in the tree */ 9989 sqlite3_int64 iRowid; /* Rowid for current entry */ 9990 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9991 int eParentWithin; /* Visibility of parent node */ 9992 int eWithin; /* OUT: Visibility */ 9993 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9994 /* The following fields are only available in 3.8.11 and later */ 9995 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9996}; 9997 9998/* 9999** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10000*/ 10001#define NOT_WITHIN 0 /* Object completely outside of query region */ 10002#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10003#define FULLY_WITHIN 2 /* Object fully contained within query region */ 10004 10005 10006#ifdef __cplusplus 10007} /* end of the 'extern "C"' block */ 10008#endif 10009 10010#endif /* ifndef _SQLITE3RTREE_H_ */ 10011 10012/******** End of sqlite3rtree.h *********/ 10013/******** Begin file sqlite3session.h *********/ 10014 10015#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10016#define __SQLITESESSION_H_ 1 10017 10018/* 10019** Make sure we can call this stuff from C++. 10020*/ 10021#ifdef __cplusplus 10022extern "C" { 10023#endif 10024 10025 10026/* 10027** CAPI3REF: Session Object Handle 10028** 10029** An instance of this object is a [session] that can be used to 10030** record changes to a database. 10031*/ 10032typedef struct sqlite3_session sqlite3_session; 10033 10034/* 10035** CAPI3REF: Changeset Iterator Handle 10036** 10037** An instance of this object acts as a cursor for iterating 10038** over the elements of a [changeset] or [patchset]. 10039*/ 10040typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10041 10042/* 10043** CAPI3REF: Create A New Session Object 10044** CONSTRUCTOR: sqlite3_session 10045** 10046** Create a new session object attached to database handle db. If successful, 10047** a pointer to the new object is written to *ppSession and SQLITE_OK is 10048** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10049** error code (e.g. SQLITE_NOMEM) is returned. 10050** 10051** It is possible to create multiple session objects attached to a single 10052** database handle. 10053** 10054** Session objects created using this function should be deleted using the 10055** [sqlite3session_delete()] function before the database handle that they 10056** are attached to is itself closed. If the database handle is closed before 10057** the session object is deleted, then the results of calling any session 10058** module function, including [sqlite3session_delete()] on the session object 10059** are undefined. 10060** 10061** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10062** is not possible for an application to register a pre-update hook on a 10063** database handle that has one or more session objects attached. Nor is 10064** it possible to create a session object attached to a database handle for 10065** which a pre-update hook is already defined. The results of attempting 10066** either of these things are undefined. 10067** 10068** The session object will be used to create changesets for tables in 10069** database zDb, where zDb is either "main", or "temp", or the name of an 10070** attached database. It is not an error if database zDb is not attached 10071** to the database when the session object is created. 10072*/ 10073SQLITE_API int sqlite3session_create( 10074 sqlite3 *db, /* Database handle */ 10075 const char *zDb, /* Name of db (e.g. "main") */ 10076 sqlite3_session **ppSession /* OUT: New session object */ 10077); 10078 10079/* 10080** CAPI3REF: Delete A Session Object 10081** DESTRUCTOR: sqlite3_session 10082** 10083** Delete a session object previously allocated using 10084** [sqlite3session_create()]. Once a session object has been deleted, the 10085** results of attempting to use pSession with any other session module 10086** function are undefined. 10087** 10088** Session objects must be deleted before the database handle to which they 10089** are attached is closed. Refer to the documentation for 10090** [sqlite3session_create()] for details. 10091*/ 10092SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10093 10094 10095/* 10096** CAPI3REF: Enable Or Disable A Session Object 10097** METHOD: sqlite3_session 10098** 10099** Enable or disable the recording of changes by a session object. When 10100** enabled, a session object records changes made to the database. When 10101** disabled - it does not. A newly created session object is enabled. 10102** Refer to the documentation for [sqlite3session_changeset()] for further 10103** details regarding how enabling and disabling a session object affects 10104** the eventual changesets. 10105** 10106** Passing zero to this function disables the session. Passing a value 10107** greater than zero enables it. Passing a value less than zero is a 10108** no-op, and may be used to query the current state of the session. 10109** 10110** The return value indicates the final state of the session object: 0 if 10111** the session is disabled, or 1 if it is enabled. 10112*/ 10113SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10114 10115/* 10116** CAPI3REF: Set Or Clear the Indirect Change Flag 10117** METHOD: sqlite3_session 10118** 10119** Each change recorded by a session object is marked as either direct or 10120** indirect. A change is marked as indirect if either: 10121** 10122** <ul> 10123** <li> The session object "indirect" flag is set when the change is 10124** made, or 10125** <li> The change is made by an SQL trigger or foreign key action 10126** instead of directly as a result of a users SQL statement. 10127** </ul> 10128** 10129** If a single row is affected by more than one operation within a session, 10130** then the change is considered indirect if all operations meet the criteria 10131** for an indirect change above, or direct otherwise. 10132** 10133** This function is used to set, clear or query the session object indirect 10134** flag. If the second argument passed to this function is zero, then the 10135** indirect flag is cleared. If it is greater than zero, the indirect flag 10136** is set. Passing a value less than zero does not modify the current value 10137** of the indirect flag, and may be used to query the current state of the 10138** indirect flag for the specified session object. 10139** 10140** The return value indicates the final state of the indirect flag: 0 if 10141** it is clear, or 1 if it is set. 10142*/ 10143SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10144 10145/* 10146** CAPI3REF: Attach A Table To A Session Object 10147** METHOD: sqlite3_session 10148** 10149** If argument zTab is not NULL, then it is the name of a table to attach 10150** to the session object passed as the first argument. All subsequent changes 10151** made to the table while the session object is enabled will be recorded. See 10152** documentation for [sqlite3session_changeset()] for further details. 10153** 10154** Or, if argument zTab is NULL, then changes are recorded for all tables 10155** in the database. If additional tables are added to the database (by 10156** executing "CREATE TABLE" statements) after this call is made, changes for 10157** the new tables are also recorded. 10158** 10159** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10160** defined as part of their CREATE TABLE statement. It does not matter if the 10161** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10162** KEY may consist of a single column, or may be a composite key. 10163** 10164** It is not an error if the named table does not exist in the database. Nor 10165** is it an error if the named table does not have a PRIMARY KEY. However, 10166** no changes will be recorded in either of these scenarios. 10167** 10168** Changes are not recorded for individual rows that have NULL values stored 10169** in one or more of their PRIMARY KEY columns. 10170** 10171** SQLITE_OK is returned if the call completes without error. Or, if an error 10172** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10173** 10174** <h3>Special sqlite_stat1 Handling</h3> 10175** 10176** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10177** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10178** <pre> 10179** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10180** </pre> 10181** 10182** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10183** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10184** are recorded for rows for which (idx IS NULL) is true. However, for such 10185** rows a zero-length blob (SQL value X'') is stored in the changeset or 10186** patchset instead of a NULL value. This allows such changesets to be 10187** manipulated by legacy implementations of sqlite3changeset_invert(), 10188** concat() and similar. 10189** 10190** The sqlite3changeset_apply() function automatically converts the 10191** zero-length blob back to a NULL value when updating the sqlite_stat1 10192** table. However, if the application calls sqlite3changeset_new(), 10193** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10194** iterator directly (including on a changeset iterator passed to a 10195** conflict-handler callback) then the X'' value is returned. The application 10196** must translate X'' to NULL itself if required. 10197** 10198** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10199** changes made to the sqlite_stat1 table. Legacy versions of the 10200** sqlite3changeset_apply() function silently ignore any modifications to the 10201** sqlite_stat1 table that are part of a changeset or patchset. 10202*/ 10203SQLITE_API int sqlite3session_attach( 10204 sqlite3_session *pSession, /* Session object */ 10205 const char *zTab /* Table name */ 10206); 10207 10208/* 10209** CAPI3REF: Set a table filter on a Session Object. 10210** METHOD: sqlite3_session 10211** 10212** The second argument (xFilter) is the "filter callback". For changes to rows 10213** in tables that are not attached to the Session object, the filter is called 10214** to determine whether changes to the table's rows should be tracked or not. 10215** If xFilter returns 0, changes are not tracked. Note that once a table is 10216** attached, xFilter will not be called again. 10217*/ 10218SQLITE_API void sqlite3session_table_filter( 10219 sqlite3_session *pSession, /* Session object */ 10220 int(*xFilter)( 10221 void *pCtx, /* Copy of third arg to _filter_table() */ 10222 const char *zTab /* Table name */ 10223 ), 10224 void *pCtx /* First argument passed to xFilter */ 10225); 10226 10227/* 10228** CAPI3REF: Generate A Changeset From A Session Object 10229** METHOD: sqlite3_session 10230** 10231** Obtain a changeset containing changes to the tables attached to the 10232** session object passed as the first argument. If successful, 10233** set *ppChangeset to point to a buffer containing the changeset 10234** and *pnChangeset to the size of the changeset in bytes before returning 10235** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10236** zero and return an SQLite error code. 10237** 10238** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10239** each representing a change to a single row of an attached table. An INSERT 10240** change contains the values of each field of a new database row. A DELETE 10241** contains the original values of each field of a deleted database row. An 10242** UPDATE change contains the original values of each field of an updated 10243** database row along with the updated values for each updated non-primary-key 10244** column. It is not possible for an UPDATE change to represent a change that 10245** modifies the values of primary key columns. If such a change is made, it 10246** is represented in a changeset as a DELETE followed by an INSERT. 10247** 10248** Changes are not recorded for rows that have NULL values stored in one or 10249** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10250** no corresponding change is present in the changesets returned by this 10251** function. If an existing row with one or more NULL values stored in 10252** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10253** only an INSERT is appears in the changeset. Similarly, if an existing row 10254** with non-NULL PRIMARY KEY values is updated so that one or more of its 10255** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10256** DELETE change only. 10257** 10258** The contents of a changeset may be traversed using an iterator created 10259** using the [sqlite3changeset_start()] API. A changeset may be applied to 10260** a database with a compatible schema using the [sqlite3changeset_apply()] 10261** API. 10262** 10263** Within a changeset generated by this function, all changes related to a 10264** single table are grouped together. In other words, when iterating through 10265** a changeset or when applying a changeset to a database, all changes related 10266** to a single table are processed before moving on to the next table. Tables 10267** are sorted in the same order in which they were attached (or auto-attached) 10268** to the sqlite3_session object. The order in which the changes related to 10269** a single table are stored is undefined. 10270** 10271** Following a successful call to this function, it is the responsibility of 10272** the caller to eventually free the buffer that *ppChangeset points to using 10273** [sqlite3_free()]. 10274** 10275** <h3>Changeset Generation</h3> 10276** 10277** Once a table has been attached to a session object, the session object 10278** records the primary key values of all new rows inserted into the table. 10279** It also records the original primary key and other column values of any 10280** deleted or updated rows. For each unique primary key value, data is only 10281** recorded once - the first time a row with said primary key is inserted, 10282** updated or deleted in the lifetime of the session. 10283** 10284** There is one exception to the previous paragraph: when a row is inserted, 10285** updated or deleted, if one or more of its primary key columns contain a 10286** NULL value, no record of the change is made. 10287** 10288** The session object therefore accumulates two types of records - those 10289** that consist of primary key values only (created when the user inserts 10290** a new record) and those that consist of the primary key values and the 10291** original values of other table columns (created when the users deletes 10292** or updates a record). 10293** 10294** When this function is called, the requested changeset is created using 10295** both the accumulated records and the current contents of the database 10296** file. Specifically: 10297** 10298** <ul> 10299** <li> For each record generated by an insert, the database is queried 10300** for a row with a matching primary key. If one is found, an INSERT 10301** change is added to the changeset. If no such row is found, no change 10302** is added to the changeset. 10303** 10304** <li> For each record generated by an update or delete, the database is 10305** queried for a row with a matching primary key. If such a row is 10306** found and one or more of the non-primary key fields have been 10307** modified from their original values, an UPDATE change is added to 10308** the changeset. Or, if no such row is found in the table, a DELETE 10309** change is added to the changeset. If there is a row with a matching 10310** primary key in the database, but all fields contain their original 10311** values, no change is added to the changeset. 10312** </ul> 10313** 10314** This means, amongst other things, that if a row is inserted and then later 10315** deleted while a session object is active, neither the insert nor the delete 10316** will be present in the changeset. Or if a row is deleted and then later a 10317** row with the same primary key values inserted while a session object is 10318** active, the resulting changeset will contain an UPDATE change instead of 10319** a DELETE and an INSERT. 10320** 10321** When a session object is disabled (see the [sqlite3session_enable()] API), 10322** it does not accumulate records when rows are inserted, updated or deleted. 10323** This may appear to have some counter-intuitive effects if a single row 10324** is written to more than once during a session. For example, if a row 10325** is inserted while a session object is enabled, then later deleted while 10326** the same session object is disabled, no INSERT record will appear in the 10327** changeset, even though the delete took place while the session was disabled. 10328** Or, if one field of a row is updated while a session is disabled, and 10329** another field of the same row is updated while the session is enabled, the 10330** resulting changeset will contain an UPDATE change that updates both fields. 10331*/ 10332SQLITE_API int sqlite3session_changeset( 10333 sqlite3_session *pSession, /* Session object */ 10334 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 10335 void **ppChangeset /* OUT: Buffer containing changeset */ 10336); 10337 10338/* 10339** CAPI3REF: Load The Difference Between Tables Into A Session 10340** METHOD: sqlite3_session 10341** 10342** If it is not already attached to the session object passed as the first 10343** argument, this function attaches table zTbl in the same manner as the 10344** [sqlite3session_attach()] function. If zTbl does not exist, or if it 10345** does not have a primary key, this function is a no-op (but does not return 10346** an error). 10347** 10348** Argument zFromDb must be the name of a database ("main", "temp" etc.) 10349** attached to the same database handle as the session object that contains 10350** a table compatible with the table attached to the session by this function. 10351** A table is considered compatible if it: 10352** 10353** <ul> 10354** <li> Has the same name, 10355** <li> Has the same set of columns declared in the same order, and 10356** <li> Has the same PRIMARY KEY definition. 10357** </ul> 10358** 10359** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 10360** are compatible but do not have any PRIMARY KEY columns, it is not an error 10361** but no changes are added to the session object. As with other session 10362** APIs, tables without PRIMARY KEYs are simply ignored. 10363** 10364** This function adds a set of changes to the session object that could be 10365** used to update the table in database zFrom (call this the "from-table") 10366** so that its content is the same as the table attached to the session 10367** object (call this the "to-table"). Specifically: 10368** 10369** <ul> 10370** <li> For each row (primary key) that exists in the to-table but not in 10371** the from-table, an INSERT record is added to the session object. 10372** 10373** <li> For each row (primary key) that exists in the to-table but not in 10374** the from-table, a DELETE record is added to the session object. 10375** 10376** <li> For each row (primary key) that exists in both tables, but features 10377** different non-PK values in each, an UPDATE record is added to the 10378** session. 10379** </ul> 10380** 10381** To clarify, if this function is called and then a changeset constructed 10382** using [sqlite3session_changeset()], then after applying that changeset to 10383** database zFrom the contents of the two compatible tables would be 10384** identical. 10385** 10386** It an error if database zFrom does not exist or does not contain the 10387** required compatible table. 10388** 10389** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 10390** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 10391** may be set to point to a buffer containing an English language error 10392** message. It is the responsibility of the caller to free this buffer using 10393** sqlite3_free(). 10394*/ 10395SQLITE_API int sqlite3session_diff( 10396 sqlite3_session *pSession, 10397 const char *zFromDb, 10398 const char *zTbl, 10399 char **pzErrMsg 10400); 10401 10402 10403/* 10404** CAPI3REF: Generate A Patchset From A Session Object 10405** METHOD: sqlite3_session 10406** 10407** The differences between a patchset and a changeset are that: 10408** 10409** <ul> 10410** <li> DELETE records consist of the primary key fields only. The 10411** original values of other fields are omitted. 10412** <li> The original values of any modified fields are omitted from 10413** UPDATE records. 10414** </ul> 10415** 10416** A patchset blob may be used with up to date versions of all 10417** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10418** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10419** attempting to use a patchset blob with old versions of the 10420** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10421** 10422** Because the non-primary key "old.*" fields are omitted, no 10423** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 10424** is passed to the sqlite3changeset_apply() API. Other conflict types work 10425** in the same way as for changesets. 10426** 10427** Changes within a patchset are ordered in the same way as for changesets 10428** generated by the sqlite3session_changeset() function (i.e. all changes for 10429** a single table are grouped together, tables appear in the order in which 10430** they were attached to the session object). 10431*/ 10432SQLITE_API int sqlite3session_patchset( 10433 sqlite3_session *pSession, /* Session object */ 10434 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 10435 void **ppPatchset /* OUT: Buffer containing patchset */ 10436); 10437 10438/* 10439** CAPI3REF: Test if a changeset has recorded any changes. 10440** 10441** Return non-zero if no changes to attached tables have been recorded by 10442** the session object passed as the first argument. Otherwise, if one or 10443** more changes have been recorded, return zero. 10444** 10445** Even if this function returns zero, it is possible that calling 10446** [sqlite3session_changeset()] on the session handle may still return a 10447** changeset that contains no changes. This can happen when a row in 10448** an attached table is modified and then later on the original values 10449** are restored. However, if this function returns non-zero, then it is 10450** guaranteed that a call to sqlite3session_changeset() will return a 10451** changeset containing zero changes. 10452*/ 10453SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 10454 10455/* 10456** CAPI3REF: Query for the amount of heap memory used by a session object. 10457** 10458** This API returns the total amount of heap memory in bytes currently 10459** used by the session object passed as the only argument. 10460*/ 10461SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 10462 10463/* 10464** CAPI3REF: Create An Iterator To Traverse A Changeset 10465** CONSTRUCTOR: sqlite3_changeset_iter 10466** 10467** Create an iterator used to iterate through the contents of a changeset. 10468** If successful, *pp is set to point to the iterator handle and SQLITE_OK 10469** is returned. Otherwise, if an error occurs, *pp is set to zero and an 10470** SQLite error code is returned. 10471** 10472** The following functions can be used to advance and query a changeset 10473** iterator created by this function: 10474** 10475** <ul> 10476** <li> [sqlite3changeset_next()] 10477** <li> [sqlite3changeset_op()] 10478** <li> [sqlite3changeset_new()] 10479** <li> [sqlite3changeset_old()] 10480** </ul> 10481** 10482** It is the responsibility of the caller to eventually destroy the iterator 10483** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 10484** changeset (pChangeset) must remain valid until after the iterator is 10485** destroyed. 10486** 10487** Assuming the changeset blob was created by one of the 10488** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 10489** [sqlite3changeset_invert()] functions, all changes within the changeset 10490** that apply to a single table are grouped together. This means that when 10491** an application iterates through a changeset using an iterator created by 10492** this function, all changes that relate to a single table are visited 10493** consecutively. There is no chance that the iterator will visit a change 10494** the applies to table X, then one for table Y, and then later on visit 10495** another change for table X. 10496** 10497** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 10498** may be modified by passing a combination of 10499** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 10500** 10501** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 10502** and therefore subject to change. 10503*/ 10504SQLITE_API int sqlite3changeset_start( 10505 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10506 int nChangeset, /* Size of changeset blob in bytes */ 10507 void *pChangeset /* Pointer to blob containing changeset */ 10508); 10509SQLITE_API int sqlite3changeset_start_v2( 10510 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10511 int nChangeset, /* Size of changeset blob in bytes */ 10512 void *pChangeset, /* Pointer to blob containing changeset */ 10513 int flags /* SESSION_CHANGESETSTART_* flags */ 10514); 10515 10516/* 10517** CAPI3REF: Flags for sqlite3changeset_start_v2 10518** 10519** The following flags may passed via the 4th parameter to 10520** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 10521** 10522** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10523** Invert the changeset while iterating through it. This is equivalent to 10524** inverting a changeset using sqlite3changeset_invert() before applying it. 10525** It is an error to specify this flag with a patchset. 10526*/ 10527#define SQLITE_CHANGESETSTART_INVERT 0x0002 10528 10529 10530/* 10531** CAPI3REF: Advance A Changeset Iterator 10532** METHOD: sqlite3_changeset_iter 10533** 10534** This function may only be used with iterators created by the function 10535** [sqlite3changeset_start()]. If it is called on an iterator passed to 10536** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 10537** is returned and the call has no effect. 10538** 10539** Immediately after an iterator is created by sqlite3changeset_start(), it 10540** does not point to any change in the changeset. Assuming the changeset 10541** is not empty, the first call to this function advances the iterator to 10542** point to the first change in the changeset. Each subsequent call advances 10543** the iterator to point to the next change in the changeset (if any). If 10544** no error occurs and the iterator points to a valid change after a call 10545** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10546** Otherwise, if all changes in the changeset have already been visited, 10547** SQLITE_DONE is returned. 10548** 10549** If an error occurs, an SQLite error code is returned. Possible error 10550** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 10551** SQLITE_NOMEM. 10552*/ 10553SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10554 10555/* 10556** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10557** METHOD: sqlite3_changeset_iter 10558** 10559** The pIter argument passed to this function may either be an iterator 10560** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10561** created by [sqlite3changeset_start()]. In the latter case, the most recent 10562** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 10563** is not the case, this function returns [SQLITE_MISUSE]. 10564** 10565** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 10566** outputs are set through these pointers: 10567** 10568** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 10569** depending on the type of change that the iterator currently points to; 10570** 10571** *pnCol is set to the number of columns in the table affected by the change; and 10572** 10573** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 10574** the name of the table affected by the current change. The buffer remains 10575** valid until either sqlite3changeset_next() is called on the iterator 10576** or until the conflict-handler function returns. 10577** 10578** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 10579** is an indirect change, or false (0) otherwise. See the documentation for 10580** [sqlite3session_indirect()] for a description of direct and indirect 10581** changes. 10582** 10583** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10584** SQLite error code is returned. The values of the output variables may not 10585** be trusted in this case. 10586*/ 10587SQLITE_API int sqlite3changeset_op( 10588 sqlite3_changeset_iter *pIter, /* Iterator object */ 10589 const char **pzTab, /* OUT: Pointer to table name */ 10590 int *pnCol, /* OUT: Number of columns in table */ 10591 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10592 int *pbIndirect /* OUT: True for an 'indirect' change */ 10593); 10594 10595/* 10596** CAPI3REF: Obtain The Primary Key Definition Of A Table 10597** METHOD: sqlite3_changeset_iter 10598** 10599** For each modified table, a changeset includes the following: 10600** 10601** <ul> 10602** <li> The number of columns in the table, and 10603** <li> Which of those columns make up the tables PRIMARY KEY. 10604** </ul> 10605** 10606** This function is used to find which columns comprise the PRIMARY KEY of 10607** the table modified by the change that iterator pIter currently points to. 10608** If successful, *pabPK is set to point to an array of nCol entries, where 10609** nCol is the number of columns in the table. Elements of *pabPK are set to 10610** 0x01 if the corresponding column is part of the tables primary key, or 10611** 0x00 if it is not. 10612** 10613** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10614** in the table. 10615** 10616** If this function is called when the iterator does not point to a valid 10617** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10618** SQLITE_OK is returned and the output variables populated as described 10619** above. 10620*/ 10621SQLITE_API int sqlite3changeset_pk( 10622 sqlite3_changeset_iter *pIter, /* Iterator object */ 10623 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10624 int *pnCol /* OUT: Number of entries in output array */ 10625); 10626 10627/* 10628** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10629** METHOD: sqlite3_changeset_iter 10630** 10631** The pIter argument passed to this function may either be an iterator 10632** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10633** created by [sqlite3changeset_start()]. In the latter case, the most recent 10634** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10635** Furthermore, it may only be called if the type of change that the iterator 10636** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10637** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10638** 10639** Argument iVal must be greater than or equal to 0, and less than the number 10640** of columns in the table affected by the current change. Otherwise, 10641** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10642** 10643** If successful, this function sets *ppValue to point to a protected 10644** sqlite3_value object containing the iVal'th value from the vector of 10645** original row values stored as part of the UPDATE or DELETE change and 10646** returns SQLITE_OK. The name of the function comes from the fact that this 10647** is similar to the "old.*" columns available to update or delete triggers. 10648** 10649** If some other error occurs (e.g. an OOM condition), an SQLite error code 10650** is returned and *ppValue is set to NULL. 10651*/ 10652SQLITE_API int sqlite3changeset_old( 10653 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10654 int iVal, /* Column number */ 10655 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10656); 10657 10658/* 10659** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10660** METHOD: sqlite3_changeset_iter 10661** 10662** The pIter argument passed to this function may either be an iterator 10663** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10664** created by [sqlite3changeset_start()]. In the latter case, the most recent 10665** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10666** Furthermore, it may only be called if the type of change that the iterator 10667** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10668** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10669** 10670** Argument iVal must be greater than or equal to 0, and less than the number 10671** of columns in the table affected by the current change. Otherwise, 10672** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10673** 10674** If successful, this function sets *ppValue to point to a protected 10675** sqlite3_value object containing the iVal'th value from the vector of 10676** new row values stored as part of the UPDATE or INSERT change and 10677** returns SQLITE_OK. If the change is an UPDATE and does not include 10678** a new value for the requested column, *ppValue is set to NULL and 10679** SQLITE_OK returned. The name of the function comes from the fact that 10680** this is similar to the "new.*" columns available to update or delete 10681** triggers. 10682** 10683** If some other error occurs (e.g. an OOM condition), an SQLite error code 10684** is returned and *ppValue is set to NULL. 10685*/ 10686SQLITE_API int sqlite3changeset_new( 10687 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10688 int iVal, /* Column number */ 10689 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10690); 10691 10692/* 10693** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10694** METHOD: sqlite3_changeset_iter 10695** 10696** This function should only be used with iterator objects passed to a 10697** conflict-handler callback by [sqlite3changeset_apply()] with either 10698** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10699** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10700** is set to NULL. 10701** 10702** Argument iVal must be greater than or equal to 0, and less than the number 10703** of columns in the table affected by the current change. Otherwise, 10704** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10705** 10706** If successful, this function sets *ppValue to point to a protected 10707** sqlite3_value object containing the iVal'th value from the 10708** "conflicting row" associated with the current conflict-handler callback 10709** and returns SQLITE_OK. 10710** 10711** If some other error occurs (e.g. an OOM condition), an SQLite error code 10712** is returned and *ppValue is set to NULL. 10713*/ 10714SQLITE_API int sqlite3changeset_conflict( 10715 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10716 int iVal, /* Column number */ 10717 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10718); 10719 10720/* 10721** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10722** METHOD: sqlite3_changeset_iter 10723** 10724** This function may only be called with an iterator passed to an 10725** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10726** it sets the output variable to the total number of known foreign key 10727** violations in the destination database and returns SQLITE_OK. 10728** 10729** In all other cases this function returns SQLITE_MISUSE. 10730*/ 10731SQLITE_API int sqlite3changeset_fk_conflicts( 10732 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10733 int *pnOut /* OUT: Number of FK violations */ 10734); 10735 10736 10737/* 10738** CAPI3REF: Finalize A Changeset Iterator 10739** METHOD: sqlite3_changeset_iter 10740** 10741** This function is used to finalize an iterator allocated with 10742** [sqlite3changeset_start()]. 10743** 10744** This function should only be called on iterators created using the 10745** [sqlite3changeset_start()] function. If an application calls this 10746** function with an iterator passed to a conflict-handler by 10747** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10748** call has no effect. 10749** 10750** If an error was encountered within a call to an sqlite3changeset_xxx() 10751** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10752** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10753** to that error is returned by this function. Otherwise, SQLITE_OK is 10754** returned. This is to allow the following pattern (pseudo-code): 10755** 10756** <pre> 10757** sqlite3changeset_start(); 10758** while( SQLITE_ROW==sqlite3changeset_next() ){ 10759** // Do something with change. 10760** } 10761** rc = sqlite3changeset_finalize(); 10762** if( rc!=SQLITE_OK ){ 10763** // An error has occurred 10764** } 10765** </pre> 10766*/ 10767SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10768 10769/* 10770** CAPI3REF: Invert A Changeset 10771** 10772** This function is used to "invert" a changeset object. Applying an inverted 10773** changeset to a database reverses the effects of applying the uninverted 10774** changeset. Specifically: 10775** 10776** <ul> 10777** <li> Each DELETE change is changed to an INSERT, and 10778** <li> Each INSERT change is changed to a DELETE, and 10779** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10780** </ul> 10781** 10782** This function does not change the order in which changes appear within 10783** the changeset. It merely reverses the sense of each individual change. 10784** 10785** If successful, a pointer to a buffer containing the inverted changeset 10786** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10787** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10788** zeroed and an SQLite error code returned. 10789** 10790** It is the responsibility of the caller to eventually call sqlite3_free() 10791** on the *ppOut pointer to free the buffer allocation following a successful 10792** call to this function. 10793** 10794** WARNING/TODO: This function currently assumes that the input is a valid 10795** changeset. If it is not, the results are undefined. 10796*/ 10797SQLITE_API int sqlite3changeset_invert( 10798 int nIn, const void *pIn, /* Input changeset */ 10799 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10800); 10801 10802/* 10803** CAPI3REF: Concatenate Two Changeset Objects 10804** 10805** This function is used to concatenate two changesets, A and B, into a 10806** single changeset. The result is a changeset equivalent to applying 10807** changeset A followed by changeset B. 10808** 10809** This function combines the two input changesets using an 10810** sqlite3_changegroup object. Calling it produces similar results as the 10811** following code fragment: 10812** 10813** <pre> 10814** sqlite3_changegroup *pGrp; 10815** rc = sqlite3_changegroup_new(&pGrp); 10816** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10817** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10818** if( rc==SQLITE_OK ){ 10819** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10820** }else{ 10821** *ppOut = 0; 10822** *pnOut = 0; 10823** } 10824** </pre> 10825** 10826** Refer to the sqlite3_changegroup documentation below for details. 10827*/ 10828SQLITE_API int sqlite3changeset_concat( 10829 int nA, /* Number of bytes in buffer pA */ 10830 void *pA, /* Pointer to buffer containing changeset A */ 10831 int nB, /* Number of bytes in buffer pB */ 10832 void *pB, /* Pointer to buffer containing changeset B */ 10833 int *pnOut, /* OUT: Number of bytes in output changeset */ 10834 void **ppOut /* OUT: Buffer containing output changeset */ 10835); 10836 10837 10838/* 10839** CAPI3REF: Changegroup Handle 10840** 10841** A changegroup is an object used to combine two or more 10842** [changesets] or [patchsets] 10843*/ 10844typedef struct sqlite3_changegroup sqlite3_changegroup; 10845 10846/* 10847** CAPI3REF: Create A New Changegroup Object 10848** CONSTRUCTOR: sqlite3_changegroup 10849** 10850** An sqlite3_changegroup object is used to combine two or more changesets 10851** (or patchsets) into a single changeset (or patchset). A single changegroup 10852** object may combine changesets or patchsets, but not both. The output is 10853** always in the same format as the input. 10854** 10855** If successful, this function returns SQLITE_OK and populates (*pp) with 10856** a pointer to a new sqlite3_changegroup object before returning. The caller 10857** should eventually free the returned object using a call to 10858** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10859** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10860** 10861** The usual usage pattern for an sqlite3_changegroup object is as follows: 10862** 10863** <ul> 10864** <li> It is created using a call to sqlite3changegroup_new(). 10865** 10866** <li> Zero or more changesets (or patchsets) are added to the object 10867** by calling sqlite3changegroup_add(). 10868** 10869** <li> The result of combining all input changesets together is obtained 10870** by the application via a call to sqlite3changegroup_output(). 10871** 10872** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10873** </ul> 10874** 10875** Any number of calls to add() and output() may be made between the calls to 10876** new() and delete(), and in any order. 10877** 10878** As well as the regular sqlite3changegroup_add() and 10879** sqlite3changegroup_output() functions, also available are the streaming 10880** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10881*/ 10882SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10883 10884/* 10885** CAPI3REF: Add A Changeset To A Changegroup 10886** METHOD: sqlite3_changegroup 10887** 10888** Add all changes within the changeset (or patchset) in buffer pData (size 10889** nData bytes) to the changegroup. 10890** 10891** If the buffer contains a patchset, then all prior calls to this function 10892** on the same changegroup object must also have specified patchsets. Or, if 10893** the buffer contains a changeset, so must have the earlier calls to this 10894** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10895** to the changegroup. 10896** 10897** Rows within the changeset and changegroup are identified by the values in 10898** their PRIMARY KEY columns. A change in the changeset is considered to 10899** apply to the same row as a change already present in the changegroup if 10900** the two rows have the same primary key. 10901** 10902** Changes to rows that do not already appear in the changegroup are 10903** simply copied into it. Or, if both the new changeset and the changegroup 10904** contain changes that apply to a single row, the final contents of the 10905** changegroup depends on the type of each change, as follows: 10906** 10907** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10908** <tr><th style="white-space:pre">Existing Change </th> 10909** <th style="white-space:pre">New Change </th> 10910** <th>Output Change 10911** <tr><td>INSERT <td>INSERT <td> 10912** The new change is ignored. This case does not occur if the new 10913** changeset was recorded immediately after the changesets already 10914** added to the changegroup. 10915** <tr><td>INSERT <td>UPDATE <td> 10916** The INSERT change remains in the changegroup. The values in the 10917** INSERT change are modified as if the row was inserted by the 10918** existing change and then updated according to the new change. 10919** <tr><td>INSERT <td>DELETE <td> 10920** The existing INSERT is removed from the changegroup. The DELETE is 10921** not added. 10922** <tr><td>UPDATE <td>INSERT <td> 10923** The new change is ignored. This case does not occur if the new 10924** changeset was recorded immediately after the changesets already 10925** added to the changegroup. 10926** <tr><td>UPDATE <td>UPDATE <td> 10927** The existing UPDATE remains within the changegroup. It is amended 10928** so that the accompanying values are as if the row was updated once 10929** by the existing change and then again by the new change. 10930** <tr><td>UPDATE <td>DELETE <td> 10931** The existing UPDATE is replaced by the new DELETE within the 10932** changegroup. 10933** <tr><td>DELETE <td>INSERT <td> 10934** If one or more of the column values in the row inserted by the 10935** new change differ from those in the row deleted by the existing 10936** change, the existing DELETE is replaced by an UPDATE within the 10937** changegroup. Otherwise, if the inserted row is exactly the same 10938** as the deleted row, the existing DELETE is simply discarded. 10939** <tr><td>DELETE <td>UPDATE <td> 10940** The new change is ignored. This case does not occur if the new 10941** changeset was recorded immediately after the changesets already 10942** added to the changegroup. 10943** <tr><td>DELETE <td>DELETE <td> 10944** The new change is ignored. This case does not occur if the new 10945** changeset was recorded immediately after the changesets already 10946** added to the changegroup. 10947** </table> 10948** 10949** If the new changeset contains changes to a table that is already present 10950** in the changegroup, then the number of columns and the position of the 10951** primary key columns for the table must be consistent. If this is not the 10952** case, this function fails with SQLITE_SCHEMA. If the input changeset 10953** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10954** returned. Or, if an out-of-memory condition occurs during processing, this 10955** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 10956** of the final contents of the changegroup is undefined. 10957** 10958** If no error occurs, SQLITE_OK is returned. 10959*/ 10960SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10961 10962/* 10963** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10964** METHOD: sqlite3_changegroup 10965** 10966** Obtain a buffer containing a changeset (or patchset) representing the 10967** current contents of the changegroup. If the inputs to the changegroup 10968** were themselves changesets, the output is a changeset. Or, if the 10969** inputs were patchsets, the output is also a patchset. 10970** 10971** As with the output of the sqlite3session_changeset() and 10972** sqlite3session_patchset() functions, all changes related to a single 10973** table are grouped together in the output of this function. Tables appear 10974** in the same order as for the very first changeset added to the changegroup. 10975** If the second or subsequent changesets added to the changegroup contain 10976** changes for tables that do not appear in the first changeset, they are 10977** appended onto the end of the output changeset, again in the order in 10978** which they are first encountered. 10979** 10980** If an error occurs, an SQLite error code is returned and the output 10981** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10982** is returned and the output variables are set to the size of and a 10983** pointer to the output buffer, respectively. In this case it is the 10984** responsibility of the caller to eventually free the buffer using a 10985** call to sqlite3_free(). 10986*/ 10987SQLITE_API int sqlite3changegroup_output( 10988 sqlite3_changegroup*, 10989 int *pnData, /* OUT: Size of output buffer in bytes */ 10990 void **ppData /* OUT: Pointer to output buffer */ 10991); 10992 10993/* 10994** CAPI3REF: Delete A Changegroup Object 10995** DESTRUCTOR: sqlite3_changegroup 10996*/ 10997SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10998 10999/* 11000** CAPI3REF: Apply A Changeset To A Database 11001** 11002** Apply a changeset or patchset to a database. These functions attempt to 11003** update the "main" database attached to handle db with the changes found in 11004** the changeset passed via the second and third arguments. 11005** 11006** The fourth argument (xFilter) passed to these functions is the "filter 11007** callback". If it is not NULL, then for each table affected by at least one 11008** change in the changeset, the filter callback is invoked with 11009** the table name as the second argument, and a copy of the context pointer 11010** passed as the sixth argument as the first. If the "filter callback" 11011** returns zero, then no attempt is made to apply any changes to the table. 11012** Otherwise, if the return value is non-zero or the xFilter argument to 11013** is NULL, all changes related to the table are attempted. 11014** 11015** For each table that is not excluded by the filter callback, this function 11016** tests that the target database contains a compatible table. A table is 11017** considered compatible if all of the following are true: 11018** 11019** <ul> 11020** <li> The table has the same name as the name recorded in the 11021** changeset, and 11022** <li> The table has at least as many columns as recorded in the 11023** changeset, and 11024** <li> The table has primary key columns in the same position as 11025** recorded in the changeset. 11026** </ul> 11027** 11028** If there is no compatible table, it is not an error, but none of the 11029** changes associated with the table are applied. A warning message is issued 11030** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 11031** one such warning is issued for each table in the changeset. 11032** 11033** For each change for which there is a compatible table, an attempt is made 11034** to modify the table contents according to the UPDATE, INSERT or DELETE 11035** change. If a change cannot be applied cleanly, the conflict handler 11036** function passed as the fifth argument to sqlite3changeset_apply() may be 11037** invoked. A description of exactly when the conflict handler is invoked for 11038** each type of change is below. 11039** 11040** Unlike the xFilter argument, xConflict may not be passed NULL. The results 11041** of passing anything other than a valid function pointer as the xConflict 11042** argument are undefined. 11043** 11044** Each time the conflict handler function is invoked, it must return one 11045** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 11046** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 11047** if the second argument passed to the conflict handler is either 11048** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 11049** returns an illegal value, any changes already made are rolled back and 11050** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 11051** actions are taken by sqlite3changeset_apply() depending on the value 11052** returned by each invocation of the conflict-handler function. Refer to 11053** the documentation for the three 11054** [SQLITE_CHANGESET_OMIT|available return values] for details. 11055** 11056** <dl> 11057** <dt>DELETE Changes<dd> 11058** For each DELETE change, the function checks if the target database 11059** contains a row with the same primary key value (or values) as the 11060** original row values stored in the changeset. If it does, and the values 11061** stored in all non-primary key columns also match the values stored in 11062** the changeset the row is deleted from the target database. 11063** 11064** If a row with matching primary key values is found, but one or more of 11065** the non-primary key fields contains a value different from the original 11066** row value stored in the changeset, the conflict-handler function is 11067** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 11068** database table has more columns than are recorded in the changeset, 11069** only the values of those non-primary key fields are compared against 11070** the current database contents - any trailing database table columns 11071** are ignored. 11072** 11073** If no row with matching primary key values is found in the database, 11074** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11075** passed as the second argument. 11076** 11077** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 11078** (which can only happen if a foreign key constraint is violated), the 11079** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 11080** passed as the second argument. This includes the case where the DELETE 11081** operation is attempted because an earlier call to the conflict handler 11082** function returned [SQLITE_CHANGESET_REPLACE]. 11083** 11084** <dt>INSERT Changes<dd> 11085** For each INSERT change, an attempt is made to insert the new row into 11086** the database. If the changeset row contains fewer fields than the 11087** database table, the trailing fields are populated with their default 11088** values. 11089** 11090** If the attempt to insert the row fails because the database already 11091** contains a row with the same primary key values, the conflict handler 11092** function is invoked with the second argument set to 11093** [SQLITE_CHANGESET_CONFLICT]. 11094** 11095** If the attempt to insert the row fails because of some other constraint 11096** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11097** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11098** This includes the case where the INSERT operation is re-attempted because 11099** an earlier call to the conflict handler function returned 11100** [SQLITE_CHANGESET_REPLACE]. 11101** 11102** <dt>UPDATE Changes<dd> 11103** For each UPDATE change, the function checks if the target database 11104** contains a row with the same primary key value (or values) as the 11105** original row values stored in the changeset. If it does, and the values 11106** stored in all modified non-primary key columns also match the values 11107** stored in the changeset the row is updated within the target database. 11108** 11109** If a row with matching primary key values is found, but one or more of 11110** the modified non-primary key fields contains a value different from an 11111** original row value stored in the changeset, the conflict-handler function 11112** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11113** UPDATE changes only contain values for non-primary key fields that are 11114** to be modified, only those fields need to match the original values to 11115** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11116** 11117** If no row with matching primary key values is found in the database, 11118** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11119** passed as the second argument. 11120** 11121** If the UPDATE operation is attempted, but SQLite returns 11122** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11123** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11124** This includes the case where the UPDATE operation is attempted after 11125** an earlier call to the conflict handler function returned 11126** [SQLITE_CHANGESET_REPLACE]. 11127** </dl> 11128** 11129** It is safe to execute SQL statements, including those that write to the 11130** table that the callback related to, from within the xConflict callback. 11131** This can be used to further customize the application's conflict 11132** resolution strategy. 11133** 11134** All changes made by these functions are enclosed in a savepoint transaction. 11135** If any other error (aside from a constraint failure when attempting to 11136** write to the target database) occurs, then the savepoint transaction is 11137** rolled back, restoring the target database to its original state, and an 11138** SQLite error code returned. 11139** 11140** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11141** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11142** may set (*ppRebase) to point to a "rebase" that may be used with the 11143** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11144** is set to the size of the buffer in bytes. It is the responsibility of the 11145** caller to eventually free any such buffer using sqlite3_free(). The buffer 11146** is only allocated and populated if one or more conflicts were encountered 11147** while applying the patchset. See comments surrounding the sqlite3_rebaser 11148** APIs for further details. 11149** 11150** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11151** may be modified by passing a combination of 11152** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11153** 11154** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11155** and therefore subject to change. 11156*/ 11157SQLITE_API int sqlite3changeset_apply( 11158 sqlite3 *db, /* Apply change to "main" db of this handle */ 11159 int nChangeset, /* Size of changeset in bytes */ 11160 void *pChangeset, /* Changeset blob */ 11161 int(*xFilter)( 11162 void *pCtx, /* Copy of sixth arg to _apply() */ 11163 const char *zTab /* Table name */ 11164 ), 11165 int(*xConflict)( 11166 void *pCtx, /* Copy of sixth arg to _apply() */ 11167 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11168 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11169 ), 11170 void *pCtx /* First argument passed to xConflict */ 11171); 11172SQLITE_API int sqlite3changeset_apply_v2( 11173 sqlite3 *db, /* Apply change to "main" db of this handle */ 11174 int nChangeset, /* Size of changeset in bytes */ 11175 void *pChangeset, /* Changeset blob */ 11176 int(*xFilter)( 11177 void *pCtx, /* Copy of sixth arg to _apply() */ 11178 const char *zTab /* Table name */ 11179 ), 11180 int(*xConflict)( 11181 void *pCtx, /* Copy of sixth arg to _apply() */ 11182 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11183 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11184 ), 11185 void *pCtx, /* First argument passed to xConflict */ 11186 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11187 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11188); 11189 11190/* 11191** CAPI3REF: Flags for sqlite3changeset_apply_v2 11192** 11193** The following flags may passed via the 9th parameter to 11194** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11195** 11196** <dl> 11197** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11198** Usually, the sessions module encloses all operations performed by 11199** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11200** SAVEPOINT is committed if the changeset or patchset is successfully 11201** applied, or rolled back if an error occurs. Specifying this flag 11202** causes the sessions module to omit this savepoint. In this case, if the 11203** caller has an open transaction or savepoint when apply_v2() is called, 11204** it may revert the partially applied changeset by rolling it back. 11205** 11206** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11207** Invert the changeset before applying it. This is equivalent to inverting 11208** a changeset using sqlite3changeset_invert() before applying it. It is 11209** an error to specify this flag with a patchset. 11210*/ 11211#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11212#define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11213 11214/* 11215** CAPI3REF: Constants Passed To The Conflict Handler 11216** 11217** Values that may be passed as the second argument to a conflict-handler. 11218** 11219** <dl> 11220** <dt>SQLITE_CHANGESET_DATA<dd> 11221** The conflict handler is invoked with CHANGESET_DATA as the second argument 11222** when processing a DELETE or UPDATE change if a row with the required 11223** PRIMARY KEY fields is present in the database, but one or more other 11224** (non primary-key) fields modified by the update do not contain the 11225** expected "before" values. 11226** 11227** The conflicting row, in this case, is the database row with the matching 11228** primary key. 11229** 11230** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11231** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11232** argument when processing a DELETE or UPDATE change if a row with the 11233** required PRIMARY KEY fields is not present in the database. 11234** 11235** There is no conflicting row in this case. The results of invoking the 11236** sqlite3changeset_conflict() API are undefined. 11237** 11238** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11239** CHANGESET_CONFLICT is passed as the second argument to the conflict 11240** handler while processing an INSERT change if the operation would result 11241** in duplicate primary key values. 11242** 11243** The conflicting row in this case is the database row with the matching 11244** primary key. 11245** 11246** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11247** If foreign key handling is enabled, and applying a changeset leaves the 11248** database in a state containing foreign key violations, the conflict 11249** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11250** exactly once before the changeset is committed. If the conflict handler 11251** returns CHANGESET_OMIT, the changes, including those that caused the 11252** foreign key constraint violation, are committed. Or, if it returns 11253** CHANGESET_ABORT, the changeset is rolled back. 11254** 11255** No current or conflicting row information is provided. The only function 11256** it is possible to call on the supplied sqlite3_changeset_iter handle 11257** is sqlite3changeset_fk_conflicts(). 11258** 11259** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11260** If any other constraint violation occurs while applying a change (i.e. 11261** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11262** invoked with CHANGESET_CONSTRAINT as the second argument. 11263** 11264** There is no conflicting row in this case. The results of invoking the 11265** sqlite3changeset_conflict() API are undefined. 11266** 11267** </dl> 11268*/ 11269#define SQLITE_CHANGESET_DATA 1 11270#define SQLITE_CHANGESET_NOTFOUND 2 11271#define SQLITE_CHANGESET_CONFLICT 3 11272#define SQLITE_CHANGESET_CONSTRAINT 4 11273#define SQLITE_CHANGESET_FOREIGN_KEY 5 11274 11275/* 11276** CAPI3REF: Constants Returned By The Conflict Handler 11277** 11278** A conflict handler callback must return one of the following three values. 11279** 11280** <dl> 11281** <dt>SQLITE_CHANGESET_OMIT<dd> 11282** If a conflict handler returns this value no special action is taken. The 11283** change that caused the conflict is not applied. The session module 11284** continues to the next change in the changeset. 11285** 11286** <dt>SQLITE_CHANGESET_REPLACE<dd> 11287** This value may only be returned if the second argument to the conflict 11288** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11289** is not the case, any changes applied so far are rolled back and the 11290** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11291** 11292** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11293** handler, then the conflicting row is either updated or deleted, depending 11294** on the type of change. 11295** 11296** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11297** handler, then the conflicting row is removed from the database and a 11298** second attempt to apply the change is made. If this second attempt fails, 11299** the original row is restored to the database before continuing. 11300** 11301** <dt>SQLITE_CHANGESET_ABORT<dd> 11302** If this value is returned, any changes applied so far are rolled back 11303** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11304** </dl> 11305*/ 11306#define SQLITE_CHANGESET_OMIT 0 11307#define SQLITE_CHANGESET_REPLACE 1 11308#define SQLITE_CHANGESET_ABORT 2 11309 11310/* 11311** CAPI3REF: Rebasing changesets 11312** EXPERIMENTAL 11313** 11314** Suppose there is a site hosting a database in state S0. And that 11315** modifications are made that move that database to state S1 and a 11316** changeset recorded (the "local" changeset). Then, a changeset based 11317** on S0 is received from another site (the "remote" changeset) and 11318** applied to the database. The database is then in state 11319** (S1+"remote"), where the exact state depends on any conflict 11320** resolution decisions (OMIT or REPLACE) made while applying "remote". 11321** Rebasing a changeset is to update it to take those conflict 11322** resolution decisions into account, so that the same conflicts 11323** do not have to be resolved elsewhere in the network. 11324** 11325** For example, if both the local and remote changesets contain an 11326** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 11327** 11328** local: INSERT INTO t1 VALUES(1, 'v1'); 11329** remote: INSERT INTO t1 VALUES(1, 'v2'); 11330** 11331** and the conflict resolution is REPLACE, then the INSERT change is 11332** removed from the local changeset (it was overridden). Or, if the 11333** conflict resolution was "OMIT", then the local changeset is modified 11334** to instead contain: 11335** 11336** UPDATE t1 SET b = 'v2' WHERE a=1; 11337** 11338** Changes within the local changeset are rebased as follows: 11339** 11340** <dl> 11341** <dt>Local INSERT<dd> 11342** This may only conflict with a remote INSERT. If the conflict 11343** resolution was OMIT, then add an UPDATE change to the rebased 11344** changeset. Or, if the conflict resolution was REPLACE, add 11345** nothing to the rebased changeset. 11346** 11347** <dt>Local DELETE<dd> 11348** This may conflict with a remote UPDATE or DELETE. In both cases the 11349** only possible resolution is OMIT. If the remote operation was a 11350** DELETE, then add no change to the rebased changeset. If the remote 11351** operation was an UPDATE, then the old.* fields of change are updated 11352** to reflect the new.* values in the UPDATE. 11353** 11354** <dt>Local UPDATE<dd> 11355** This may conflict with a remote UPDATE or DELETE. If it conflicts 11356** with a DELETE, and the conflict resolution was OMIT, then the update 11357** is changed into an INSERT. Any undefined values in the new.* record 11358** from the update change are filled in using the old.* values from 11359** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 11360** the UPDATE change is simply omitted from the rebased changeset. 11361** 11362** If conflict is with a remote UPDATE and the resolution is OMIT, then 11363** the old.* values are rebased using the new.* values in the remote 11364** change. Or, if the resolution is REPLACE, then the change is copied 11365** into the rebased changeset with updates to columns also updated by 11366** the conflicting remote UPDATE removed. If this means no columns would 11367** be updated, the change is omitted. 11368** </dl> 11369** 11370** A local change may be rebased against multiple remote changes 11371** simultaneously. If a single key is modified by multiple remote 11372** changesets, they are combined as follows before the local changeset 11373** is rebased: 11374** 11375** <ul> 11376** <li> If there has been one or more REPLACE resolutions on a 11377** key, it is rebased according to a REPLACE. 11378** 11379** <li> If there have been no REPLACE resolutions on a key, then 11380** the local changeset is rebased according to the most recent 11381** of the OMIT resolutions. 11382** </ul> 11383** 11384** Note that conflict resolutions from multiple remote changesets are 11385** combined on a per-field basis, not per-row. This means that in the 11386** case of multiple remote UPDATE operations, some fields of a single 11387** local change may be rebased for REPLACE while others are rebased for 11388** OMIT. 11389** 11390** In order to rebase a local changeset, the remote changeset must first 11391** be applied to the local database using sqlite3changeset_apply_v2() and 11392** the buffer of rebase information captured. Then: 11393** 11394** <ol> 11395** <li> An sqlite3_rebaser object is created by calling 11396** sqlite3rebaser_create(). 11397** <li> The new object is configured with the rebase buffer obtained from 11398** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 11399** If the local changeset is to be rebased against multiple remote 11400** changesets, then sqlite3rebaser_configure() should be called 11401** multiple times, in the same order that the multiple 11402** sqlite3changeset_apply_v2() calls were made. 11403** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 11404** <li> The sqlite3_rebaser object is deleted by calling 11405** sqlite3rebaser_delete(). 11406** </ol> 11407*/ 11408typedef struct sqlite3_rebaser sqlite3_rebaser; 11409 11410/* 11411** CAPI3REF: Create a changeset rebaser object. 11412** EXPERIMENTAL 11413** 11414** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 11415** point to the new object and return SQLITE_OK. Otherwise, if an error 11416** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 11417** to NULL. 11418*/ 11419SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 11420 11421/* 11422** CAPI3REF: Configure a changeset rebaser object. 11423** EXPERIMENTAL 11424** 11425** Configure the changeset rebaser object to rebase changesets according 11426** to the conflict resolutions described by buffer pRebase (size nRebase 11427** bytes), which must have been obtained from a previous call to 11428** sqlite3changeset_apply_v2(). 11429*/ 11430SQLITE_API int sqlite3rebaser_configure( 11431 sqlite3_rebaser*, 11432 int nRebase, const void *pRebase 11433); 11434 11435/* 11436** CAPI3REF: Rebase a changeset 11437** EXPERIMENTAL 11438** 11439** Argument pIn must point to a buffer containing a changeset nIn bytes 11440** in size. This function allocates and populates a buffer with a copy 11441** of the changeset rebased according to the configuration of the 11442** rebaser object passed as the first argument. If successful, (*ppOut) 11443** is set to point to the new buffer containing the rebased changeset and 11444** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 11445** responsibility of the caller to eventually free the new buffer using 11446** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 11447** are set to zero and an SQLite error code returned. 11448*/ 11449SQLITE_API int sqlite3rebaser_rebase( 11450 sqlite3_rebaser*, 11451 int nIn, const void *pIn, 11452 int *pnOut, void **ppOut 11453); 11454 11455/* 11456** CAPI3REF: Delete a changeset rebaser object. 11457** EXPERIMENTAL 11458** 11459** Delete the changeset rebaser object and all associated resources. There 11460** should be one call to this function for each successful invocation 11461** of sqlite3rebaser_create(). 11462*/ 11463SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 11464 11465/* 11466** CAPI3REF: Streaming Versions of API functions. 11467** 11468** The six streaming API xxx_strm() functions serve similar purposes to the 11469** corresponding non-streaming API functions: 11470** 11471** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11472** <tr><th>Streaming function<th>Non-streaming equivalent</th> 11473** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 11474** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 11475** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 11476** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 11477** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 11478** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 11479** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 11480** </table> 11481** 11482** Non-streaming functions that accept changesets (or patchsets) as input 11483** require that the entire changeset be stored in a single buffer in memory. 11484** Similarly, those that return a changeset or patchset do so by returning 11485** a pointer to a single large buffer allocated using sqlite3_malloc(). 11486** Normally this is convenient. However, if an application running in a 11487** low-memory environment is required to handle very large changesets, the 11488** large contiguous memory allocations required can become onerous. 11489** 11490** In order to avoid this problem, instead of a single large buffer, input 11491** is passed to a streaming API functions by way of a callback function that 11492** the sessions module invokes to incrementally request input data as it is 11493** required. In all cases, a pair of API function parameters such as 11494** 11495** <pre> 11496** int nChangeset, 11497** void *pChangeset, 11498** </pre> 11499** 11500** Is replaced by: 11501** 11502** <pre> 11503** int (*xInput)(void *pIn, void *pData, int *pnData), 11504** void *pIn, 11505** </pre> 11506** 11507** Each time the xInput callback is invoked by the sessions module, the first 11508** argument passed is a copy of the supplied pIn context pointer. The second 11509** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 11510** error occurs the xInput method should copy up to (*pnData) bytes of data 11511** into the buffer and set (*pnData) to the actual number of bytes copied 11512** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 11513** should be set to zero to indicate this. Or, if an error occurs, an SQLite 11514** error code should be returned. In all cases, if an xInput callback returns 11515** an error, all processing is abandoned and the streaming API function 11516** returns a copy of the error code to the caller. 11517** 11518** In the case of sqlite3changeset_start_strm(), the xInput callback may be 11519** invoked by the sessions module at any point during the lifetime of the 11520** iterator. If such an xInput callback returns an error, the iterator enters 11521** an error state, whereby all subsequent calls to iterator functions 11522** immediately fail with the same error code as returned by xInput. 11523** 11524** Similarly, streaming API functions that return changesets (or patchsets) 11525** return them in chunks by way of a callback function instead of via a 11526** pointer to a single large buffer. In this case, a pair of parameters such 11527** as: 11528** 11529** <pre> 11530** int *pnChangeset, 11531** void **ppChangeset, 11532** </pre> 11533** 11534** Is replaced by: 11535** 11536** <pre> 11537** int (*xOutput)(void *pOut, const void *pData, int nData), 11538** void *pOut 11539** </pre> 11540** 11541** The xOutput callback is invoked zero or more times to return data to 11542** the application. The first parameter passed to each call is a copy of the 11543** pOut pointer supplied by the application. The second parameter, pData, 11544** points to a buffer nData bytes in size containing the chunk of output 11545** data being returned. If the xOutput callback successfully processes the 11546** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 11547** it should return some other SQLite error code. In this case processing 11548** is immediately abandoned and the streaming API function returns a copy 11549** of the xOutput error code to the application. 11550** 11551** The sessions module never invokes an xOutput callback with the third 11552** parameter set to a value less than or equal to zero. Other than this, 11553** no guarantees are made as to the size of the chunks of data returned. 11554*/ 11555SQLITE_API int sqlite3changeset_apply_strm( 11556 sqlite3 *db, /* Apply change to "main" db of this handle */ 11557 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11558 void *pIn, /* First arg for xInput */ 11559 int(*xFilter)( 11560 void *pCtx, /* Copy of sixth arg to _apply() */ 11561 const char *zTab /* Table name */ 11562 ), 11563 int(*xConflict)( 11564 void *pCtx, /* Copy of sixth arg to _apply() */ 11565 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11566 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11567 ), 11568 void *pCtx /* First argument passed to xConflict */ 11569); 11570SQLITE_API int sqlite3changeset_apply_v2_strm( 11571 sqlite3 *db, /* Apply change to "main" db of this handle */ 11572 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11573 void *pIn, /* First arg for xInput */ 11574 int(*xFilter)( 11575 void *pCtx, /* Copy of sixth arg to _apply() */ 11576 const char *zTab /* Table name */ 11577 ), 11578 int(*xConflict)( 11579 void *pCtx, /* Copy of sixth arg to _apply() */ 11580 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11581 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11582 ), 11583 void *pCtx, /* First argument passed to xConflict */ 11584 void **ppRebase, int *pnRebase, 11585 int flags 11586); 11587SQLITE_API int sqlite3changeset_concat_strm( 11588 int (*xInputA)(void *pIn, void *pData, int *pnData), 11589 void *pInA, 11590 int (*xInputB)(void *pIn, void *pData, int *pnData), 11591 void *pInB, 11592 int (*xOutput)(void *pOut, const void *pData, int nData), 11593 void *pOut 11594); 11595SQLITE_API int sqlite3changeset_invert_strm( 11596 int (*xInput)(void *pIn, void *pData, int *pnData), 11597 void *pIn, 11598 int (*xOutput)(void *pOut, const void *pData, int nData), 11599 void *pOut 11600); 11601SQLITE_API int sqlite3changeset_start_strm( 11602 sqlite3_changeset_iter **pp, 11603 int (*xInput)(void *pIn, void *pData, int *pnData), 11604 void *pIn 11605); 11606SQLITE_API int sqlite3changeset_start_v2_strm( 11607 sqlite3_changeset_iter **pp, 11608 int (*xInput)(void *pIn, void *pData, int *pnData), 11609 void *pIn, 11610 int flags 11611); 11612SQLITE_API int sqlite3session_changeset_strm( 11613 sqlite3_session *pSession, 11614 int (*xOutput)(void *pOut, const void *pData, int nData), 11615 void *pOut 11616); 11617SQLITE_API int sqlite3session_patchset_strm( 11618 sqlite3_session *pSession, 11619 int (*xOutput)(void *pOut, const void *pData, int nData), 11620 void *pOut 11621); 11622SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11623 int (*xInput)(void *pIn, void *pData, int *pnData), 11624 void *pIn 11625); 11626SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11627 int (*xOutput)(void *pOut, const void *pData, int nData), 11628 void *pOut 11629); 11630SQLITE_API int sqlite3rebaser_rebase_strm( 11631 sqlite3_rebaser *pRebaser, 11632 int (*xInput)(void *pIn, void *pData, int *pnData), 11633 void *pIn, 11634 int (*xOutput)(void *pOut, const void *pData, int nData), 11635 void *pOut 11636); 11637 11638/* 11639** CAPI3REF: Configure global parameters 11640** 11641** The sqlite3session_config() interface is used to make global configuration 11642** changes to the sessions module in order to tune it to the specific needs 11643** of the application. 11644** 11645** The sqlite3session_config() interface is not threadsafe. If it is invoked 11646** while any other thread is inside any other sessions method then the 11647** results are undefined. Furthermore, if it is invoked after any sessions 11648** related objects have been created, the results are also undefined. 11649** 11650** The first argument to the sqlite3session_config() function must be one 11651** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11652** interpretation of the (void*) value passed as the second parameter and 11653** the effect of calling this function depends on the value of the first 11654** parameter. 11655** 11656** <dl> 11657** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11658** By default, the sessions module streaming interfaces attempt to input 11659** and output data in approximately 1 KiB chunks. This operand may be used 11660** to set and query the value of this configuration setting. The pointer 11661** passed as the second argument must point to a value of type (int). 11662** If this value is greater than 0, it is used as the new streaming data 11663** chunk size for both input and output. Before returning, the (int) value 11664** pointed to by pArg is set to the final value of the streaming interface 11665** chunk size. 11666** </dl> 11667** 11668** This function returns SQLITE_OK if successful, or an SQLite error code 11669** otherwise. 11670*/ 11671SQLITE_API int sqlite3session_config(int op, void *pArg); 11672 11673/* 11674** CAPI3REF: Values for sqlite3session_config(). 11675*/ 11676#define SQLITE_SESSION_CONFIG_STRMSIZE 1 11677 11678/* 11679** Make sure we can call this stuff from C++. 11680*/ 11681#ifdef __cplusplus 11682} 11683#endif 11684 11685#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11686 11687/******** End of sqlite3session.h *********/ 11688/******** Begin file fts5.h *********/ 11689/* 11690** 2014 May 31 11691** 11692** The author disclaims copyright to this source code. In place of 11693** a legal notice, here is a blessing: 11694** 11695** May you do good and not evil. 11696** May you find forgiveness for yourself and forgive others. 11697** May you share freely, never taking more than you give. 11698** 11699****************************************************************************** 11700** 11701** Interfaces to extend FTS5. Using the interfaces defined in this file, 11702** FTS5 may be extended with: 11703** 11704** * custom tokenizers, and 11705** * custom auxiliary functions. 11706*/ 11707 11708 11709#ifndef _FTS5_H 11710#define _FTS5_H 11711 11712 11713#ifdef __cplusplus 11714extern "C" { 11715#endif 11716 11717/************************************************************************* 11718** CUSTOM AUXILIARY FUNCTIONS 11719** 11720** Virtual table implementations may overload SQL functions by implementing 11721** the sqlite3_module.xFindFunction() method. 11722*/ 11723 11724typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11725typedef struct Fts5Context Fts5Context; 11726typedef struct Fts5PhraseIter Fts5PhraseIter; 11727 11728typedef void (*fts5_extension_function)( 11729 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11730 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11731 sqlite3_context *pCtx, /* Context for returning result/error */ 11732 int nVal, /* Number of values in apVal[] array */ 11733 sqlite3_value **apVal /* Array of trailing arguments */ 11734); 11735 11736struct Fts5PhraseIter { 11737 const unsigned char *a; 11738 const unsigned char *b; 11739}; 11740 11741/* 11742** EXTENSION API FUNCTIONS 11743** 11744** xUserData(pFts): 11745** Return a copy of the context pointer the extension function was 11746** registered with. 11747** 11748** xColumnTotalSize(pFts, iCol, pnToken): 11749** If parameter iCol is less than zero, set output variable *pnToken 11750** to the total number of tokens in the FTS5 table. Or, if iCol is 11751** non-negative but less than the number of columns in the table, return 11752** the total number of tokens in column iCol, considering all rows in 11753** the FTS5 table. 11754** 11755** If parameter iCol is greater than or equal to the number of columns 11756** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11757** an OOM condition or IO error), an appropriate SQLite error code is 11758** returned. 11759** 11760** xColumnCount(pFts): 11761** Return the number of columns in the table. 11762** 11763** xColumnSize(pFts, iCol, pnToken): 11764** If parameter iCol is less than zero, set output variable *pnToken 11765** to the total number of tokens in the current row. Or, if iCol is 11766** non-negative but less than the number of columns in the table, set 11767** *pnToken to the number of tokens in column iCol of the current row. 11768** 11769** If parameter iCol is greater than or equal to the number of columns 11770** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11771** an OOM condition or IO error), an appropriate SQLite error code is 11772** returned. 11773** 11774** This function may be quite inefficient if used with an FTS5 table 11775** created with the "columnsize=0" option. 11776** 11777** xColumnText: 11778** This function attempts to retrieve the text of column iCol of the 11779** current document. If successful, (*pz) is set to point to a buffer 11780** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11781** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11782** if an error occurs, an SQLite error code is returned and the final values 11783** of (*pz) and (*pn) are undefined. 11784** 11785** xPhraseCount: 11786** Returns the number of phrases in the current query expression. 11787** 11788** xPhraseSize: 11789** Returns the number of tokens in phrase iPhrase of the query. Phrases 11790** are numbered starting from zero. 11791** 11792** xInstCount: 11793** Set *pnInst to the total number of occurrences of all phrases within 11794** the query within the current row. Return SQLITE_OK if successful, or 11795** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11796** 11797** This API can be quite slow if used with an FTS5 table created with the 11798** "detail=none" or "detail=column" option. If the FTS5 table is created 11799** with either "detail=none" or "detail=column" and "content=" option 11800** (i.e. if it is a contentless table), then this API always returns 0. 11801** 11802** xInst: 11803** Query for the details of phrase match iIdx within the current row. 11804** Phrase matches are numbered starting from zero, so the iIdx argument 11805** should be greater than or equal to zero and smaller than the value 11806** output by xInstCount(). 11807** 11808** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11809** to the column in which it occurs and *piOff the token offset of the 11810** first token of the phrase. Returns SQLITE_OK if successful, or an error 11811** code (i.e. SQLITE_NOMEM) if an error occurs. 11812** 11813** This API can be quite slow if used with an FTS5 table created with the 11814** "detail=none" or "detail=column" option. 11815** 11816** xRowid: 11817** Returns the rowid of the current row. 11818** 11819** xTokenize: 11820** Tokenize text using the tokenizer belonging to the FTS5 table. 11821** 11822** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11823** This API function is used to query the FTS table for phrase iPhrase 11824** of the current query. Specifically, a query equivalent to: 11825** 11826** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11827** 11828** with $p set to a phrase equivalent to the phrase iPhrase of the 11829** current query is executed. Any column filter that applies to 11830** phrase iPhrase of the current query is included in $p. For each 11831** row visited, the callback function passed as the fourth argument 11832** is invoked. The context and API objects passed to the callback 11833** function may be used to access the properties of each matched row. 11834** Invoking Api.xUserData() returns a copy of the pointer passed as 11835** the third argument to pUserData. 11836** 11837** If the callback function returns any value other than SQLITE_OK, the 11838** query is abandoned and the xQueryPhrase function returns immediately. 11839** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11840** Otherwise, the error code is propagated upwards. 11841** 11842** If the query runs to completion without incident, SQLITE_OK is returned. 11843** Or, if some error occurs before the query completes or is aborted by 11844** the callback, an SQLite error code is returned. 11845** 11846** 11847** xSetAuxdata(pFts5, pAux, xDelete) 11848** 11849** Save the pointer passed as the second argument as the extension function's 11850** "auxiliary data". The pointer may then be retrieved by the current or any 11851** future invocation of the same fts5 extension function made as part of 11852** the same MATCH query using the xGetAuxdata() API. 11853** 11854** Each extension function is allocated a single auxiliary data slot for 11855** each FTS query (MATCH expression). If the extension function is invoked 11856** more than once for a single FTS query, then all invocations share a 11857** single auxiliary data context. 11858** 11859** If there is already an auxiliary data pointer when this function is 11860** invoked, then it is replaced by the new pointer. If an xDelete callback 11861** was specified along with the original pointer, it is invoked at this 11862** point. 11863** 11864** The xDelete callback, if one is specified, is also invoked on the 11865** auxiliary data pointer after the FTS5 query has finished. 11866** 11867** If an error (e.g. an OOM condition) occurs within this function, 11868** the auxiliary data is set to NULL and an error code returned. If the 11869** xDelete parameter was not NULL, it is invoked on the auxiliary data 11870** pointer before returning. 11871** 11872** 11873** xGetAuxdata(pFts5, bClear) 11874** 11875** Returns the current auxiliary data pointer for the fts5 extension 11876** function. See the xSetAuxdata() method for details. 11877** 11878** If the bClear argument is non-zero, then the auxiliary data is cleared 11879** (set to NULL) before this function returns. In this case the xDelete, 11880** if any, is not invoked. 11881** 11882** 11883** xRowCount(pFts5, pnRow) 11884** 11885** This function is used to retrieve the total number of rows in the table. 11886** In other words, the same value that would be returned by: 11887** 11888** SELECT count(*) FROM ftstable; 11889** 11890** xPhraseFirst() 11891** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11892** method, to iterate through all instances of a single query phrase within 11893** the current row. This is the same information as is accessible via the 11894** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11895** to use, this API may be faster under some circumstances. To iterate 11896** through instances of phrase iPhrase, use the following code: 11897** 11898** Fts5PhraseIter iter; 11899** int iCol, iOff; 11900** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11901** iCol>=0; 11902** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11903** ){ 11904** // An instance of phrase iPhrase at offset iOff of column iCol 11905** } 11906** 11907** The Fts5PhraseIter structure is defined above. Applications should not 11908** modify this structure directly - it should only be used as shown above 11909** with the xPhraseFirst() and xPhraseNext() API methods (and by 11910** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11911** 11912** This API can be quite slow if used with an FTS5 table created with the 11913** "detail=none" or "detail=column" option. If the FTS5 table is created 11914** with either "detail=none" or "detail=column" and "content=" option 11915** (i.e. if it is a contentless table), then this API always iterates 11916** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11917** 11918** xPhraseNext() 11919** See xPhraseFirst above. 11920** 11921** xPhraseFirstColumn() 11922** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11923** and xPhraseNext() APIs described above. The difference is that instead 11924** of iterating through all instances of a phrase in the current row, these 11925** APIs are used to iterate through the set of columns in the current row 11926** that contain one or more instances of a specified phrase. For example: 11927** 11928** Fts5PhraseIter iter; 11929** int iCol; 11930** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11931** iCol>=0; 11932** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11933** ){ 11934** // Column iCol contains at least one instance of phrase iPhrase 11935** } 11936** 11937** This API can be quite slow if used with an FTS5 table created with the 11938** "detail=none" option. If the FTS5 table is created with either 11939** "detail=none" "content=" option (i.e. if it is a contentless table), 11940** then this API always iterates through an empty set (all calls to 11941** xPhraseFirstColumn() set iCol to -1). 11942** 11943** The information accessed using this API and its companion 11944** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11945** (or xInst/xInstCount). The chief advantage of this API is that it is 11946** significantly more efficient than those alternatives when used with 11947** "detail=column" tables. 11948** 11949** xPhraseNextColumn() 11950** See xPhraseFirstColumn above. 11951*/ 11952struct Fts5ExtensionApi { 11953 int iVersion; /* Currently always set to 3 */ 11954 11955 void *(*xUserData)(Fts5Context*); 11956 11957 int (*xColumnCount)(Fts5Context*); 11958 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11959 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11960 11961 int (*xTokenize)(Fts5Context*, 11962 const char *pText, int nText, /* Text to tokenize */ 11963 void *pCtx, /* Context passed to xToken() */ 11964 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11965 ); 11966 11967 int (*xPhraseCount)(Fts5Context*); 11968 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11969 11970 int (*xInstCount)(Fts5Context*, int *pnInst); 11971 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11972 11973 sqlite3_int64 (*xRowid)(Fts5Context*); 11974 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11975 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11976 11977 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11978 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11979 ); 11980 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11981 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11982 11983 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11984 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11985 11986 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11987 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11988}; 11989 11990/* 11991** CUSTOM AUXILIARY FUNCTIONS 11992*************************************************************************/ 11993 11994/************************************************************************* 11995** CUSTOM TOKENIZERS 11996** 11997** Applications may also register custom tokenizer types. A tokenizer 11998** is registered by providing fts5 with a populated instance of the 11999** following structure. All structure methods must be defined, setting 12000** any member of the fts5_tokenizer struct to NULL leads to undefined 12001** behaviour. The structure methods are expected to function as follows: 12002** 12003** xCreate: 12004** This function is used to allocate and initialize a tokenizer instance. 12005** A tokenizer instance is required to actually tokenize text. 12006** 12007** The first argument passed to this function is a copy of the (void*) 12008** pointer provided by the application when the fts5_tokenizer object 12009** was registered with FTS5 (the third argument to xCreateTokenizer()). 12010** The second and third arguments are an array of nul-terminated strings 12011** containing the tokenizer arguments, if any, specified following the 12012** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 12013** to create the FTS5 table. 12014** 12015** The final argument is an output variable. If successful, (*ppOut) 12016** should be set to point to the new tokenizer handle and SQLITE_OK 12017** returned. If an error occurs, some value other than SQLITE_OK should 12018** be returned. In this case, fts5 assumes that the final value of *ppOut 12019** is undefined. 12020** 12021** xDelete: 12022** This function is invoked to delete a tokenizer handle previously 12023** allocated using xCreate(). Fts5 guarantees that this function will 12024** be invoked exactly once for each successful call to xCreate(). 12025** 12026** xTokenize: 12027** This function is expected to tokenize the nText byte string indicated 12028** by argument pText. pText may or may not be nul-terminated. The first 12029** argument passed to this function is a pointer to an Fts5Tokenizer object 12030** returned by an earlier call to xCreate(). 12031** 12032** The second argument indicates the reason that FTS5 is requesting 12033** tokenization of the supplied text. This is always one of the following 12034** four values: 12035** 12036** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 12037** or removed from the FTS table. The tokenizer is being invoked to 12038** determine the set of tokens to add to (or delete from) the 12039** FTS index. 12040** 12041** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 12042** against the FTS index. The tokenizer is being called to tokenize 12043** a bareword or quoted string specified as part of the query. 12044** 12045** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 12046** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 12047** followed by a "*" character, indicating that the last token 12048** returned by the tokenizer will be treated as a token prefix. 12049** 12050** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 12051** satisfy an fts5_api.xTokenize() request made by an auxiliary 12052** function. Or an fts5_api.xColumnSize() request made by the same 12053** on a columnsize=0 database. 12054** </ul> 12055** 12056** For each token in the input string, the supplied callback xToken() must 12057** be invoked. The first argument to it should be a copy of the pointer 12058** passed as the second argument to xTokenize(). The third and fourth 12059** arguments are a pointer to a buffer containing the token text, and the 12060** size of the token in bytes. The 4th and 5th arguments are the byte offsets 12061** of the first byte of and first byte immediately following the text from 12062** which the token is derived within the input. 12063** 12064** The second argument passed to the xToken() callback ("tflags") should 12065** normally be set to 0. The exception is if the tokenizer supports 12066** synonyms. In this case see the discussion below for details. 12067** 12068** FTS5 assumes the xToken() callback is invoked for each token in the 12069** order that they occur within the input text. 12070** 12071** If an xToken() callback returns any value other than SQLITE_OK, then 12072** the tokenization should be abandoned and the xTokenize() method should 12073** immediately return a copy of the xToken() return value. Or, if the 12074** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 12075** if an error occurs with the xTokenize() implementation itself, it 12076** may abandon the tokenization and return any error code other than 12077** SQLITE_OK or SQLITE_DONE. 12078** 12079** SYNONYM SUPPORT 12080** 12081** Custom tokenizers may also support synonyms. Consider a case in which a 12082** user wishes to query for a phrase such as "first place". Using the 12083** built-in tokenizers, the FTS5 query 'first + place' will match instances 12084** of "first place" within the document set, but not alternative forms 12085** such as "1st place". In some applications, it would be better to match 12086** all instances of "first place" or "1st place" regardless of which form 12087** the user specified in the MATCH query text. 12088** 12089** There are several ways to approach this in FTS5: 12090** 12091** <ol><li> By mapping all synonyms to a single token. In this case, using 12092** the above example, this means that the tokenizer returns the 12093** same token for inputs "first" and "1st". Say that token is in 12094** fact "first", so that when the user inserts the document "I won 12095** 1st place" entries are added to the index for tokens "i", "won", 12096** "first" and "place". If the user then queries for '1st + place', 12097** the tokenizer substitutes "first" for "1st" and the query works 12098** as expected. 12099** 12100** <li> By querying the index for all synonyms of each query term 12101** separately. In this case, when tokenizing query text, the 12102** tokenizer may provide multiple synonyms for a single term 12103** within the document. FTS5 then queries the index for each 12104** synonym individually. For example, faced with the query: 12105** 12106** <codeblock> 12107** ... MATCH 'first place'</codeblock> 12108** 12109** the tokenizer offers both "1st" and "first" as synonyms for the 12110** first token in the MATCH query and FTS5 effectively runs a query 12111** similar to: 12112** 12113** <codeblock> 12114** ... MATCH '(first OR 1st) place'</codeblock> 12115** 12116** except that, for the purposes of auxiliary functions, the query 12117** still appears to contain just two phrases - "(first OR 1st)" 12118** being treated as a single phrase. 12119** 12120** <li> By adding multiple synonyms for a single term to the FTS index. 12121** Using this method, when tokenizing document text, the tokenizer 12122** provides multiple synonyms for each token. So that when a 12123** document such as "I won first place" is tokenized, entries are 12124** added to the FTS index for "i", "won", "first", "1st" and 12125** "place". 12126** 12127** This way, even if the tokenizer does not provide synonyms 12128** when tokenizing query text (it should not - to do so would be 12129** inefficient), it doesn't matter if the user queries for 12130** 'first + place' or '1st + place', as there are entries in the 12131** FTS index corresponding to both forms of the first token. 12132** </ol> 12133** 12134** Whether it is parsing document or query text, any call to xToken that 12135** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12136** is considered to supply a synonym for the previous token. For example, 12137** when parsing the document "I won first place", a tokenizer that supports 12138** synonyms would call xToken() 5 times, as follows: 12139** 12140** <codeblock> 12141** xToken(pCtx, 0, "i", 1, 0, 1); 12142** xToken(pCtx, 0, "won", 3, 2, 5); 12143** xToken(pCtx, 0, "first", 5, 6, 11); 12144** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12145** xToken(pCtx, 0, "place", 5, 12, 17); 12146**</codeblock> 12147** 12148** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12149** xToken() is called. Multiple synonyms may be specified for a single token 12150** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12151** There is no limit to the number of synonyms that may be provided for a 12152** single token. 12153** 12154** In many cases, method (1) above is the best approach. It does not add 12155** extra data to the FTS index or require FTS5 to query for multiple terms, 12156** so it is efficient in terms of disk space and query speed. However, it 12157** does not support prefix queries very well. If, as suggested above, the 12158** token "first" is substituted for "1st" by the tokenizer, then the query: 12159** 12160** <codeblock> 12161** ... MATCH '1s*'</codeblock> 12162** 12163** will not match documents that contain the token "1st" (as the tokenizer 12164** will probably not map "1s" to any prefix of "first"). 12165** 12166** For full prefix support, method (3) may be preferred. In this case, 12167** because the index contains entries for both "first" and "1st", prefix 12168** queries such as 'fi*' or '1s*' will match correctly. However, because 12169** extra entries are added to the FTS index, this method uses more space 12170** within the database. 12171** 12172** Method (2) offers a midpoint between (1) and (3). Using this method, 12173** a query such as '1s*' will match documents that contain the literal 12174** token "1st", but not "first" (assuming the tokenizer is not able to 12175** provide synonyms for prefixes). However, a non-prefix query like '1st' 12176** will match against "1st" and "first". This method does not require 12177** extra disk space, as no extra entries are added to the FTS index. 12178** On the other hand, it may require more CPU cycles to run MATCH queries, 12179** as separate queries of the FTS index are required for each synonym. 12180** 12181** When using methods (2) or (3), it is important that the tokenizer only 12182** provide synonyms when tokenizing document text (method (2)) or query 12183** text (method (3)), not both. Doing so will not cause any errors, but is 12184** inefficient. 12185*/ 12186typedef struct Fts5Tokenizer Fts5Tokenizer; 12187typedef struct fts5_tokenizer fts5_tokenizer; 12188struct fts5_tokenizer { 12189 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12190 void (*xDelete)(Fts5Tokenizer*); 12191 int (*xTokenize)(Fts5Tokenizer*, 12192 void *pCtx, 12193 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12194 const char *pText, int nText, 12195 int (*xToken)( 12196 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12197 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12198 const char *pToken, /* Pointer to buffer containing token */ 12199 int nToken, /* Size of token in bytes */ 12200 int iStart, /* Byte offset of token within input text */ 12201 int iEnd /* Byte offset of end of token within input text */ 12202 ) 12203 ); 12204}; 12205 12206/* Flags that may be passed as the third argument to xTokenize() */ 12207#define FTS5_TOKENIZE_QUERY 0x0001 12208#define FTS5_TOKENIZE_PREFIX 0x0002 12209#define FTS5_TOKENIZE_DOCUMENT 0x0004 12210#define FTS5_TOKENIZE_AUX 0x0008 12211 12212/* Flags that may be passed by the tokenizer implementation back to FTS5 12213** as the third argument to the supplied xToken callback. */ 12214#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12215 12216/* 12217** END OF CUSTOM TOKENIZERS 12218*************************************************************************/ 12219 12220/************************************************************************* 12221** FTS5 EXTENSION REGISTRATION API 12222*/ 12223typedef struct fts5_api fts5_api; 12224struct fts5_api { 12225 int iVersion; /* Currently always set to 2 */ 12226 12227 /* Create a new tokenizer */ 12228 int (*xCreateTokenizer)( 12229 fts5_api *pApi, 12230 const char *zName, 12231 void *pContext, 12232 fts5_tokenizer *pTokenizer, 12233 void (*xDestroy)(void*) 12234 ); 12235 12236 /* Find an existing tokenizer */ 12237 int (*xFindTokenizer)( 12238 fts5_api *pApi, 12239 const char *zName, 12240 void **ppContext, 12241 fts5_tokenizer *pTokenizer 12242 ); 12243 12244 /* Create a new auxiliary function */ 12245 int (*xCreateFunction)( 12246 fts5_api *pApi, 12247 const char *zName, 12248 void *pContext, 12249 fts5_extension_function xFunction, 12250 void (*xDestroy)(void*) 12251 ); 12252}; 12253 12254/* 12255** END OF REGISTRATION API 12256*************************************************************************/ 12257 12258#ifdef __cplusplus 12259} /* end of the 'extern "C"' block */ 12260#endif 12261 12262#endif /* _FTS5_H */ 12263 12264/******** End of fts5.h *********/ 12265