1/* $Id: zlib.h,v 1.7 1997/11/27 06:03:33 paulus Exp $ */ 2 3/* 4 * This file is derived from zlib.h and zconf.h from the zlib-1.0.4 5 * distribution by Jean-loup Gailly and Mark Adler, with some additions 6 * by Paul Mackerras to aid in implementing Deflate compression and 7 * decompression for PPP packets. 8 */ 9 10/* 11 * ==FILEVERSION 971127== 12 * 13 * This marker is used by the Linux installation script to determine 14 * whether an up-to-date version of this file is already installed. 15 */ 16 17 18/* +++ zlib.h */ 19/* zlib.h -- interface of the 'zlib' general purpose compression library 20 version 1.0.4, Jul 24th, 1996. 21 22 Copyright (C) 1995-1996 Jean-loup Gailly and Mark Adler 23 24 This software is provided 'as-is', without any express or implied 25 warranty. In no event will the authors be held liable for any damages 26 arising from the use of this software. 27 28 Permission is granted to anyone to use this software for any purpose, 29 including commercial applications, and to alter it and redistribute it 30 freely, subject to the following restrictions: 31 32 1. The origin of this software must not be misrepresented; you must not 33 claim that you wrote the original software. If you use this software 34 in a product, an acknowledgment in the product documentation would be 35 appreciated but is not required. 36 2. Altered source versions must be plainly marked as such, and must not be 37 misrepresented as being the original software. 38 3. This notice may not be removed or altered from any source distribution. 39 40 Jean-loup Gailly Mark Adler 41 gzip@prep.ai.mit.edu madler@alumni.caltech.edu 42 43 44 The data format used by the zlib library is described by RFCs (Request for 45 Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt 46 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). 47*/ 48 49#ifndef _ZLIB_H 50#define _ZLIB_H 51 52#ifdef __cplusplus 53extern "C" { 54#endif 55 56 57/* +++ zconf.h */ 58/* zconf.h -- configuration of the zlib compression library 59 * Copyright (C) 1995-1996 Jean-loup Gailly. 60 * For conditions of distribution and use, see copyright notice in zlib.h 61 */ 62 63/* From: zconf.h,v 1.20 1996/07/02 15:09:28 me Exp $ */ 64 65#ifndef _ZCONF_H 66#define _ZCONF_H 67 68/* 69 * If you *really* need a unique prefix for all types and library functions, 70 * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it. 71 */ 72#ifdef Z_PREFIX 73# define deflateInit_ z_deflateInit_ 74# define deflate z_deflate 75# define deflateEnd z_deflateEnd 76# define inflateInit_ z_inflateInit_ 77# define inflate z_inflate 78# define inflateEnd z_inflateEnd 79# define deflateInit2_ z_deflateInit2_ 80# define deflateSetDictionary z_deflateSetDictionary 81# define deflateCopy z_deflateCopy 82# define deflateReset z_deflateReset 83# define deflateParams z_deflateParams 84# define inflateInit2_ z_inflateInit2_ 85# define inflateSetDictionary z_inflateSetDictionary 86# define inflateSync z_inflateSync 87# define inflateReset z_inflateReset 88# define compress z_compress 89# define uncompress z_uncompress 90# define adler32 z_adler32 91# define crc32 z_crc32 92# define get_crc_table z_get_crc_table 93 94# define Byte z_Byte 95# define uInt z_uInt 96# define uLong z_uLong 97# define Bytef z_Bytef 98# define charf z_charf 99# define intf z_intf 100# define uIntf z_uIntf 101# define uLongf z_uLongf 102# define voidpf z_voidpf 103# define voidp z_voidp 104#endif 105 106#if (defined(_WIN32) || defined(__WIN32__)) && !defined(WIN32) 107# define WIN32 108#endif 109#if defined(__GNUC__) || defined(WIN32) || defined(__386__) || defined(i386) 110# ifndef __32BIT__ 111# define __32BIT__ 112# endif 113#endif 114#if defined(__MSDOS__) && !defined(MSDOS) 115# define MSDOS 116#endif 117 118/* 119 * Compile with -DMAXSEG_64K if the alloc function cannot allocate more 120 * than 64k bytes at a time (needed on systems with 16-bit int). 121 */ 122#if defined(MSDOS) && !defined(__32BIT__) 123# define MAXSEG_64K 124#endif 125#ifdef MSDOS 126# define UNALIGNED_OK 127#endif 128 129#if (defined(MSDOS) || defined(_WINDOWS) || defined(WIN32)) && !defined(STDC) 130# define STDC 131#endif 132#if (defined(__STDC__) || defined(__cplusplus)) && !defined(STDC) 133# define STDC 134#endif 135 136#ifndef STDC 137# ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */ 138# define const 139# endif 140#endif 141 142/* Some Mac compilers merge all .h files incorrectly: */ 143#if defined(__MWERKS__) || defined(applec) ||defined(THINK_C) ||defined(__SC__) 144# define NO_DUMMY_DECL 145#endif 146 147/* Maximum value for memLevel in deflateInit2 */ 148#ifndef MAX_MEM_LEVEL 149# ifdef MAXSEG_64K 150# define MAX_MEM_LEVEL 8 151# else 152# define MAX_MEM_LEVEL 9 153# endif 154#endif 155 156/* Maximum value for windowBits in deflateInit2 and inflateInit2 */ 157#ifndef MAX_WBITS 158# define MAX_WBITS 15 /* 32K LZ77 window */ 159#endif 160 161/* The memory requirements for deflate are (in bytes): 162 1 << (windowBits+2) + 1 << (memLevel+9) 163 that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values) 164 plus a few kilobytes for small objects. For example, if you want to reduce 165 the default memory requirements from 256K to 128K, compile with 166 make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7" 167 Of course this will generally degrade compression (there's no free lunch). 168 169 The memory requirements for inflate are (in bytes) 1 << windowBits 170 that is, 32K for windowBits=15 (default value) plus a few kilobytes 171 for small objects. 172*/ 173 174 /* Type declarations */ 175 176#ifndef OF /* function prototypes */ 177# ifdef STDC 178# define OF(args) args 179# else 180# define OF(args) () 181# endif 182#endif 183 184/* The following definitions for FAR are needed only for MSDOS mixed 185 * model programming (small or medium model with some far allocations). 186 * This was tested only with MSC; for other MSDOS compilers you may have 187 * to define NO_MEMCPY in zutil.h. If you don't need the mixed model, 188 * just define FAR to be empty. 189 */ 190#if (defined(M_I86SM) || defined(M_I86MM)) && !defined(__32BIT__) 191 /* MSC small or medium model */ 192# define SMALL_MEDIUM 193# ifdef _MSC_VER 194# define FAR __far 195# else 196# define FAR far 197# endif 198#endif 199#if defined(__BORLANDC__) && (defined(__SMALL__) || defined(__MEDIUM__)) 200# ifndef __32BIT__ 201# define SMALL_MEDIUM 202# define FAR __far 203# endif 204#endif 205#ifndef FAR 206# define FAR 207#endif 208 209typedef unsigned char Byte; /* 8 bits */ 210typedef unsigned int uInt; /* 16 bits or more */ 211typedef unsigned long uLong; /* 32 bits or more */ 212 213#if defined(__BORLANDC__) && defined(SMALL_MEDIUM) 214 /* Borland C/C++ ignores FAR inside typedef */ 215# define Bytef Byte FAR 216#else 217 typedef Byte FAR Bytef; 218#endif 219typedef char FAR charf; 220typedef int FAR intf; 221typedef uInt FAR uIntf; 222typedef uLong FAR uLongf; 223 224#ifdef STDC 225 typedef void FAR *voidpf; 226 typedef void *voidp; 227#else 228 typedef Byte FAR *voidpf; 229 typedef Byte *voidp; 230#endif 231 232 233/* Compile with -DZLIB_DLL for Windows DLL support */ 234#if (defined(_WINDOWS) || defined(WINDOWS)) && defined(ZLIB_DLL) 235# include <windows.h> 236# define EXPORT WINAPI 237#else 238# define EXPORT 239#endif 240 241#endif /* _ZCONF_H */ 242/* --- zconf.h */ 243 244#define ZLIB_VERSION "1.0.4P" 245 246/* 247 The 'zlib' compression library provides in-memory compression and 248 decompression functions, including integrity checks of the uncompressed 249 data. This version of the library supports only one compression method 250 (deflation) but other algorithms may be added later and will have the same 251 stream interface. 252 253 For compression the application must provide the output buffer and 254 may optionally provide the input buffer for optimization. For decompression, 255 the application must provide the input buffer and may optionally provide 256 the output buffer for optimization. 257 258 Compression can be done in a single step if the buffers are large 259 enough (for example if an input file is mmap'ed), or can be done by 260 repeated calls of the compression function. In the latter case, the 261 application must provide more input and/or consume the output 262 (providing more output space) before each call. 263 264 The library does not install any signal handler. It is recommended to 265 add at least a handler for SIGSEGV when decompressing; the library checks 266 the consistency of the input data whenever possible but may go nuts 267 for some forms of corrupted input. 268*/ 269 270typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 271typedef void (*free_func) OF((voidpf opaque, voidpf address)); 272 273struct internal_state; 274 275typedef struct z_stream_s { 276 Bytef *next_in; /* next input byte */ 277 uInt avail_in; /* number of bytes available at next_in */ 278 uLong total_in; /* total nb of input bytes read so far */ 279 280 Bytef *next_out; /* next output byte should be put there */ 281 uInt avail_out; /* remaining free space at next_out */ 282 uLong total_out; /* total nb of bytes output so far */ 283 284 char *msg; /* last error message, NULL if no error */ 285 struct internal_state FAR *state; /* not visible by applications */ 286 287 alloc_func zalloc; /* used to allocate the internal state */ 288 free_func zfree; /* used to free the internal state */ 289 voidpf opaque; /* private data object passed to zalloc and zfree */ 290 291 int data_type; /* best guess about the data type: ascii or binary */ 292 uLong adler; /* adler32 value of the uncompressed data */ 293 uLong reserved; /* reserved for future use */ 294} z_stream; 295 296typedef z_stream FAR *z_streamp; 297 298/* 299 The application must update next_in and avail_in when avail_in has 300 dropped to zero. It must update next_out and avail_out when avail_out 301 has dropped to zero. The application must initialize zalloc, zfree and 302 opaque before calling the init function. All other fields are set by the 303 compression library and must not be updated by the application. 304 305 The opaque value provided by the application will be passed as the first 306 parameter for calls of zalloc and zfree. This can be useful for custom 307 memory management. The compression library attaches no meaning to the 308 opaque value. 309 310 zalloc must return Z_NULL if there is not enough memory for the object. 311 On 16-bit systems, the functions zalloc and zfree must be able to allocate 312 exactly 65536 bytes, but will not be required to allocate more than this 313 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, 314 pointers returned by zalloc for objects of exactly 65536 bytes *must* 315 have their offset normalized to zero. The default allocation function 316 provided by this library ensures this (see zutil.c). To reduce memory 317 requirements and avoid any allocation of 64K objects, at the expense of 318 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). 319 320 The fields total_in and total_out can be used for statistics or 321 progress reports. After compression, total_in holds the total size of 322 the uncompressed data and may be saved for use in the decompressor 323 (particularly if the decompressor wants to decompress everything in 324 a single step). 325*/ 326 327 /* constants */ 328 329#define Z_NO_FLUSH 0 330#define Z_PARTIAL_FLUSH 1 331#define Z_PACKET_FLUSH 2 332#define Z_SYNC_FLUSH 3 333#define Z_FULL_FLUSH 4 334#define Z_FINISH 5 335/* Allowed flush values; see deflate() below for details */ 336 337#define Z_OK 0 338#define Z_STREAM_END 1 339#define Z_NEED_DICT 2 340#define Z_ERRNO (-1) 341#define Z_STREAM_ERROR (-2) 342#define Z_DATA_ERROR (-3) 343#define Z_MEM_ERROR (-4) 344#define Z_BUF_ERROR (-5) 345#define Z_VERSION_ERROR (-6) 346/* Return codes for the compression/decompression functions. Negative 347 * values are errors, positive values are used for special but normal events. 348 */ 349 350#define Z_NO_COMPRESSION 0 351#define Z_BEST_SPEED 1 352#define Z_BEST_COMPRESSION 9 353#define Z_DEFAULT_COMPRESSION (-1) 354/* compression levels */ 355 356#define Z_FILTERED 1 357#define Z_HUFFMAN_ONLY 2 358#define Z_DEFAULT_STRATEGY 0 359/* compression strategy; see deflateInit2() below for details */ 360 361#define Z_BINARY 0 362#define Z_ASCII 1 363#define Z_UNKNOWN 2 364/* Possible values of the data_type field */ 365 366#define Z_DEFLATED 8 367/* The deflate compression method (the only one supported in this version) */ 368 369#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 370 371#define zlib_version zlibVersion() 372/* for compatibility with versions < 1.0.2 */ 373 374 /* basic functions */ 375 376extern const char * EXPORT zlibVersion OF((void)); 377/* The application can compare zlibVersion and ZLIB_VERSION for consistency. 378 If the first character differs, the library code actually used is 379 not compatible with the zlib.h header file used by the application. 380 This check is automatically made by deflateInit and inflateInit. 381 */ 382 383/* 384extern int EXPORT deflateInit OF((z_streamp strm, int level)); 385 386 Initializes the internal stream state for compression. The fields 387 zalloc, zfree and opaque must be initialized before by the caller. 388 If zalloc and zfree are set to Z_NULL, deflateInit updates them to 389 use default allocation functions. 390 391 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 392 1 gives best speed, 9 gives best compression, 0 gives no compression at 393 all (the input data is simply copied a block at a time). 394 Z_DEFAULT_COMPRESSION requests a default compromise between speed and 395 compression (currently equivalent to level 6). 396 397 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not 398 enough memory, Z_STREAM_ERROR if level is not a valid compression level, 399 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 400 with the version assumed by the caller (ZLIB_VERSION). 401 msg is set to null if there is no error message. deflateInit does not 402 perform any compression: this will be done by deflate(). 403*/ 404 405 406extern int EXPORT deflate OF((z_streamp strm, int flush)); 407/* 408 Performs one or both of the following actions: 409 410 - Compress more input starting at next_in and update next_in and avail_in 411 accordingly. If not all input can be processed (because there is not 412 enough room in the output buffer), next_in and avail_in are updated and 413 processing will resume at this point for the next call of deflate(). 414 415 - Provide more output starting at next_out and update next_out and avail_out 416 accordingly. This action is forced if the parameter flush is non zero. 417 Forcing flush frequently degrades the compression ratio, so this parameter 418 should be set only when necessary (in interactive applications). 419 Some output may be provided even if flush is not set. 420 421 Before the call of deflate(), the application should ensure that at least 422 one of the actions is possible, by providing more input and/or consuming 423 more output, and updating avail_in or avail_out accordingly; avail_out 424 should never be zero before the call. The application can consume the 425 compressed output when it wants, for example when the output buffer is full 426 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK 427 and with zero avail_out, it must be called again after making room in the 428 output buffer because there might be more output pending. 429 430 If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression 431 block is terminated and flushed to the output buffer so that the 432 decompressor can get all input data available so far. For method 9, a future 433 variant on method 8, the current block will be flushed but not terminated. 434 Z_SYNC_FLUSH has the same effect as partial flush except that the compressed 435 output is byte aligned (the compressor can clear its internal bit buffer) 436 and the current block is always terminated; this can be useful if the 437 compressor has to be restarted from scratch after an interruption (in which 438 case the internal state of the compressor may be lost). 439 If flush is set to Z_FULL_FLUSH, the compression block is terminated, a 440 special marker is output and the compression dictionary is discarded; this 441 is useful to allow the decompressor to synchronize if one compressed block 442 has been damaged (see inflateSync below). Flushing degrades compression and 443 so should be used only when necessary. Using Z_FULL_FLUSH too often can 444 seriously degrade the compression. If deflate returns with avail_out == 0, 445 this function must be called again with the same value of the flush 446 parameter and more output space (updated avail_out), until the flush is 447 complete (deflate returns with non-zero avail_out). 448 449 If the parameter flush is set to Z_PACKET_FLUSH, the compression 450 block is terminated, and a zero-length stored block is output, 451 omitting the length bytes (the effect of this is that the 3-bit type 452 code 000 for a stored block is output, and the output is then 453 byte-aligned). This is designed for use at the end of a PPP packet. 454 455 If the parameter flush is set to Z_FINISH, pending input is processed, 456 pending output is flushed and deflate returns with Z_STREAM_END if there 457 was enough output space; if deflate returns with Z_OK, this function must be 458 called again with Z_FINISH and more output space (updated avail_out) but no 459 more input data, until it returns with Z_STREAM_END or an error. After 460 deflate has returned Z_STREAM_END, the only possible operations on the 461 stream are deflateReset or deflateEnd. 462 463 Z_FINISH can be used immediately after deflateInit if all the compression 464 is to be done in a single step. In this case, avail_out must be at least 465 0.1% larger than avail_in plus 12 bytes. If deflate does not return 466 Z_STREAM_END, then it must be called again as described above. 467 468 deflate() may update data_type if it can make a good guess about 469 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered 470 binary. This field is only for information purposes and does not affect 471 the compression algorithm in any manner. 472 473 deflate() returns Z_OK if some progress has been made (more input 474 processed or more output produced), Z_STREAM_END if all input has been 475 consumed and all output has been produced (only when flush is set to 476 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 477 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible. 478*/ 479 480 481extern int EXPORT deflateEnd OF((z_streamp strm)); 482/* 483 All dynamically allocated data structures for this stream are freed. 484 This function discards any unprocessed input and does not flush any 485 pending output. 486 487 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 488 stream state was inconsistent, Z_DATA_ERROR if the stream was freed 489 prematurely (some input or output was discarded). In the error case, 490 msg may be set but then points to a static string (which must not be 491 deallocated). 492*/ 493 494 495/* 496extern int EXPORT inflateInit OF((z_streamp strm)); 497 498 Initializes the internal stream state for decompression. The fields 499 zalloc, zfree and opaque must be initialized before by the caller. If 500 zalloc and zfree are set to Z_NULL, inflateInit updates them to use default 501 allocation functions. 502 503 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not 504 enough memory, Z_VERSION_ERROR if the zlib library version is incompatible 505 with the version assumed by the caller. msg is set to null if there is no 506 error message. inflateInit does not perform any decompression: this will be 507 done by inflate(). 508*/ 509 510 511extern int EXPORT inflate OF((z_streamp strm, int flush)); 512/* 513 Performs one or both of the following actions: 514 515 - Decompress more input starting at next_in and update next_in and avail_in 516 accordingly. If not all input can be processed (because there is not 517 enough room in the output buffer), next_in is updated and processing 518 will resume at this point for the next call of inflate(). 519 520 - Provide more output starting at next_out and update next_out and avail_out 521 accordingly. inflate() provides as much output as possible, until there 522 is no more input data or no more space in the output buffer (see below 523 about the flush parameter). 524 525 Before the call of inflate(), the application should ensure that at least 526 one of the actions is possible, by providing more input and/or consuming 527 more output, and updating the next_* and avail_* values accordingly. 528 The application can consume the uncompressed output when it wants, for 529 example when the output buffer is full (avail_out == 0), or after each 530 call of inflate(). If inflate returns Z_OK and with zero avail_out, it 531 must be called again after making room in the output buffer because there 532 might be more output pending. 533 534 If the parameter flush is set to Z_PARTIAL_FLUSH or Z_PACKET_FLUSH, 535 inflate flushes as much output as possible to the output buffer. The 536 flushing behavior of inflate is not specified for values of the flush 537 parameter other than Z_PARTIAL_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the 538 current implementation actually flushes as much output as possible 539 anyway. For Z_PACKET_FLUSH, inflate checks that once all the input data 540 has been consumed, it is expecting to see the length field of a stored 541 block; if not, it returns Z_DATA_ERROR. 542 543 inflate() should normally be called until it returns Z_STREAM_END or an 544 error. However if all decompression is to be performed in a single step 545 (a single call of inflate), the parameter flush should be set to 546 Z_FINISH. In this case all pending input is processed and all pending 547 output is flushed; avail_out must be large enough to hold all the 548 uncompressed data. (The size of the uncompressed data may have been saved 549 by the compressor for this purpose.) The next operation on this stream must 550 be inflateEnd to deallocate the decompression state. The use of Z_FINISH 551 is never required, but can be used to inform inflate that a faster routine 552 may be used for the single inflate() call. 553 554 inflate() returns Z_OK if some progress has been made (more input 555 processed or more output produced), Z_STREAM_END if the end of the 556 compressed data has been reached and all uncompressed output has been 557 produced, Z_NEED_DICT if a preset dictionary is needed at this point (see 558 inflateSetDictionary below), Z_DATA_ERROR if the input data was corrupted, 559 Z_STREAM_ERROR if the stream structure was inconsistent (for example if 560 next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, 561 Z_BUF_ERROR if no progress is possible or if there was not enough room in 562 the output buffer when Z_FINISH is used. In the Z_DATA_ERROR case, the 563 application may then call inflateSync to look for a good compression block. 564 In the Z_NEED_DICT case, strm->adler is set to the Adler32 value of the 565 dictionary chosen by the compressor. 566*/ 567 568 569extern int EXPORT inflateEnd OF((z_streamp strm)); 570/* 571 All dynamically allocated data structures for this stream are freed. 572 This function discards any unprocessed input and does not flush any 573 pending output. 574 575 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 576 was inconsistent. In the error case, msg may be set but then points to a 577 static string (which must not be deallocated). 578*/ 579 580 /* Advanced functions */ 581 582/* 583 The following functions are needed only in some special applications. 584*/ 585 586/* 587extern int EXPORT deflateInit2 OF((z_streamp strm, 588 int level, 589 int method, 590 int windowBits, 591 int memLevel, 592 int strategy)); 593 594 This is another version of deflateInit with more compression options. The 595 fields next_in, zalloc, zfree and opaque must be initialized before by 596 the caller. 597 598 The method parameter is the compression method. It must be Z_DEFLATED in 599 this version of the library. (Method 9 will allow a 64K history buffer and 600 partial block flushes.) 601 602 The windowBits parameter is the base two logarithm of the window size 603 (the size of the history buffer). It should be in the range 8..15 for this 604 version of the library (the value 16 will be allowed for method 9). Larger 605 values of this parameter result in better compression at the expense of 606 memory usage. The default value is 15 if deflateInit is used instead. 607 608 The memLevel parameter specifies how much memory should be allocated 609 for the internal compression state. memLevel=1 uses minimum memory but 610 is slow and reduces compression ratio; memLevel=9 uses maximum memory 611 for optimal speed. The default value is 8. See zconf.h for total memory 612 usage as a function of windowBits and memLevel. 613 614 The strategy parameter is used to tune the compression algorithm. Use the 615 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 616 filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no 617 string match). Filtered data consists mostly of small values with a 618 somewhat random distribution. In this case, the compression algorithm is 619 tuned to compress them better. The effect of Z_FILTERED is to force more 620 Huffman coding and less string matching; it is somewhat intermediate 621 between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects 622 the compression ratio but not the correctness of the compressed output even 623 if it is not set appropriately. 624 625 If next_in is not null, the library will use this buffer to hold also 626 some history information; the buffer must either hold the entire input 627 data, or have at least 1<<(windowBits+1) bytes and be writable. If next_in 628 is null, the library will allocate its own history buffer (and leave next_in 629 null). next_out need not be provided here but must be provided by the 630 application for the next call of deflate(). 631 632 If the history buffer is provided by the application, next_in must 633 must never be changed by the application since the compressor maintains 634 information inside this buffer from call to call; the application 635 must provide more input only by increasing avail_in. next_in is always 636 reset by the library in this case. 637 638 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was 639 not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as 640 an invalid method). msg is set to null if there is no error message. 641 deflateInit2 does not perform any compression: this will be done by 642 deflate(). 643*/ 644 645extern int EXPORT deflateSetDictionary OF((z_streamp strm, 646 const Bytef *dictionary, 647 uInt dictLength)); 648/* 649 Initializes the compression dictionary (history buffer) from the given 650 byte sequence without producing any compressed output. This function must 651 be called immediately after deflateInit or deflateInit2, before any call 652 of deflate. The compressor and decompressor must use exactly the same 653 dictionary (see inflateSetDictionary). 654 The dictionary should consist of strings (byte sequences) that are likely 655 to be encountered later in the data to be compressed, with the most commonly 656 used strings preferably put towards the end of the dictionary. Using a 657 dictionary is most useful when the data to be compressed is short and 658 can be predicted with good accuracy; the data can then be compressed better 659 than with the default empty dictionary. In this version of the library, 660 only the last 32K bytes of the dictionary are used. 661 Upon return of this function, strm->adler is set to the Adler32 value 662 of the dictionary; the decompressor may later use this value to determine 663 which dictionary has been used by the compressor. (The Adler32 value 664 applies to the whole dictionary even if only a subset of the dictionary is 665 actually used by the compressor.) 666 667 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 668 parameter is invalid (such as NULL dictionary) or the stream state 669 is inconsistent (for example if deflate has already been called for this 670 stream). deflateSetDictionary does not perform any compression: this will 671 be done by deflate(). 672*/ 673 674extern int EXPORT deflateCopy OF((z_streamp dest, 675 z_streamp source)); 676/* 677 Sets the destination stream as a complete copy of the source stream. If 678 the source stream is using an application-supplied history buffer, a new 679 buffer is allocated for the destination stream. The compressed output 680 buffer is always application-supplied. It's the responsibility of the 681 application to provide the correct values of next_out and avail_out for the 682 next call of deflate. 683 684 This function can be useful when several compression strategies will be 685 tried, for example when there are several ways of pre-processing the input 686 data with a filter. The streams that will be discarded should then be freed 687 by calling deflateEnd. Note that deflateCopy duplicates the internal 688 compression state which can be quite large, so this strategy is slow and 689 can consume lots of memory. 690 691 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 692 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 693 (such as zalloc being NULL). msg is left unchanged in both source and 694 destination. 695*/ 696 697extern int EXPORT deflateReset OF((z_streamp strm)); 698/* 699 This function is equivalent to deflateEnd followed by deflateInit, 700 but does not free and reallocate all the internal compression state. 701 The stream will keep the same compression level and any other attributes 702 that may have been set by deflateInit2. 703 704 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 705 stream state was inconsistent (such as zalloc or state being NULL). 706*/ 707 708extern int EXPORT deflateParams OF((z_streamp strm, int level, int strategy)); 709/* 710 Dynamically update the compression level and compression strategy. 711 This can be used to switch between compression and straight copy of 712 the input data, or to switch to a different kind of input data requiring 713 a different strategy. If the compression level is changed, the input 714 available so far is compressed with the old level (and may be flushed); 715 the new level will take effect only at the next call of deflate(). 716 717 Before the call of deflateParams, the stream state must be set as for 718 a call of deflate(), since the currently available input may have to 719 be compressed and flushed. In particular, strm->avail_out must be non-zero. 720 721 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source 722 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR 723 if strm->avail_out was zero. 724*/ 725 726extern int EXPORT deflateOutputPending OF((z_streamp strm)); 727/* 728 Returns the number of bytes of output which are immediately 729 available from the compressor (i.e. without any further input 730 or flush). 731*/ 732 733/* 734extern int EXPORT inflateInit2 OF((z_streamp strm, 735 int windowBits)); 736 737 This is another version of inflateInit with more compression options. The 738 fields next_out, zalloc, zfree and opaque must be initialized before by 739 the caller. 740 741 The windowBits parameter is the base two logarithm of the maximum window 742 size (the size of the history buffer). It should be in the range 8..15 for 743 this version of the library (the value 16 will be allowed soon). The 744 default value is 15 if inflateInit is used instead. If a compressed stream 745 with a larger window size is given as input, inflate() will return with 746 the error code Z_DATA_ERROR instead of trying to allocate a larger window. 747 748 If next_out is not null, the library will use this buffer for the history 749 buffer; the buffer must either be large enough to hold the entire output 750 data, or have at least 1<<windowBits bytes. If next_out is null, the 751 library will allocate its own buffer (and leave next_out null). next_in 752 need not be provided here but must be provided by the application for the 753 next call of inflate(). 754 755 If the history buffer is provided by the application, next_out must 756 never be changed by the application since the decompressor maintains 757 history information inside this buffer from call to call; the application 758 can only reset next_out to the beginning of the history buffer when 759 avail_out is zero and all output has been consumed. 760 761 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was 762 not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as 763 windowBits < 8). msg is set to null if there is no error message. 764 inflateInit2 does not perform any decompression: this will be done by 765 inflate(). 766*/ 767 768extern int EXPORT inflateSetDictionary OF((z_streamp strm, 769 const Bytef *dictionary, 770 uInt dictLength)); 771/* 772 Initializes the decompression dictionary (history buffer) from the given 773 uncompressed byte sequence. This function must be called immediately after 774 a call of inflate if this call returned Z_NEED_DICT. The dictionary chosen 775 by the compressor can be determined from the Adler32 value returned by this 776 call of inflate. The compressor and decompressor must use exactly the same 777 dictionary (see deflateSetDictionary). 778 779 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 780 parameter is invalid (such as NULL dictionary) or the stream state is 781 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 782 expected one (incorrect Adler32 value). inflateSetDictionary does not 783 perform any decompression: this will be done by subsequent calls of 784 inflate(). 785*/ 786 787extern int EXPORT inflateSync OF((z_streamp strm)); 788/* 789 Skips invalid compressed data until the special marker (see deflate() 790 above) can be found, or until all available input is skipped. No output 791 is provided. 792 793 inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR 794 if no more input was provided, Z_DATA_ERROR if no marker has been found, 795 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success 796 case, the application may save the current current value of total_in which 797 indicates where valid compressed data was found. In the error case, the 798 application may repeatedly call inflateSync, providing more input each time, 799 until success or end of the input data. 800*/ 801 802extern int EXPORT inflateReset OF((z_streamp strm)); 803/* 804 This function is equivalent to inflateEnd followed by inflateInit, 805 but does not free and reallocate all the internal decompression state. 806 The stream will keep attributes that may have been set by inflateInit2. 807 808 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 809 stream state was inconsistent (such as zalloc or state being NULL). 810*/ 811 812extern int inflateIncomp OF((z_stream *strm)); 813/* 814 This function adds the data at next_in (avail_in bytes) to the output 815 history without performing any output. There must be no pending output, 816 and the decompressor must be expecting to see the start of a block. 817 Calling this function is equivalent to decompressing a stored block 818 containing the data at next_in (except that the data is not output). 819*/ 820 821 /* utility functions */ 822 823/* 824 The following utility functions are implemented on top of the 825 basic stream-oriented functions. To simplify the interface, some 826 default options are assumed (compression level, window size, 827 standard memory allocation functions). The source code of these 828 utility functions can easily be modified if you need special options. 829*/ 830 831extern int EXPORT compress OF((Bytef *dest, uLongf *destLen, 832 const Bytef *source, uLong sourceLen)); 833/* 834 Compresses the source buffer into the destination buffer. sourceLen is 835 the byte length of the source buffer. Upon entry, destLen is the total 836 size of the destination buffer, which must be at least 0.1% larger than 837 sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the 838 compressed buffer. 839 This function can be used to compress a whole file at once if the 840 input file is mmap'ed. 841 compress returns Z_OK if success, Z_MEM_ERROR if there was not 842 enough memory, Z_BUF_ERROR if there was not enough room in the output 843 buffer. 844*/ 845 846extern int EXPORT uncompress OF((Bytef *dest, uLongf *destLen, 847 const Bytef *source, uLong sourceLen)); 848/* 849 Decompresses the source buffer into the destination buffer. sourceLen is 850 the byte length of the source buffer. Upon entry, destLen is the total 851 size of the destination buffer, which must be large enough to hold the 852 entire uncompressed data. (The size of the uncompressed data must have 853 been saved previously by the compressor and transmitted to the decompressor 854 by some mechanism outside the scope of this compression library.) 855 Upon exit, destLen is the actual size of the compressed buffer. 856 This function can be used to decompress a whole file at once if the 857 input file is mmap'ed. 858 859 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 860 enough memory, Z_BUF_ERROR if there was not enough room in the output 861 buffer, or Z_DATA_ERROR if the input data was corrupted. 862*/ 863 864 865typedef voidp gzFile; 866 867extern gzFile EXPORT gzopen OF((const char *path, const char *mode)); 868/* 869 Opens a gzip (.gz) file for reading or writing. The mode parameter 870 is as in fopen ("rb" or "wb") but can also include a compression level 871 ("wb9"). gzopen can be used to read a file which is not in gzip format; 872 in this case gzread will directly read from the file without decompression. 873 gzopen returns NULL if the file could not be opened or if there was 874 insufficient memory to allocate the (de)compression state; errno 875 can be checked to distinguish the two cases (if errno is zero, the 876 zlib error is Z_MEM_ERROR). 877*/ 878 879extern gzFile EXPORT gzdopen OF((int fd, const char *mode)); 880/* 881 gzdopen() associates a gzFile with the file descriptor fd. File 882 descriptors are obtained from calls like open, dup, creat, pipe or 883 fileno (in the file has been previously opened with fopen). 884 The mode parameter is as in gzopen. 885 The next call of gzclose on the returned gzFile will also close the 886 file descriptor fd, just like fclose(fdopen(fd), mode) closes the file 887 descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode). 888 gzdopen returns NULL if there was insufficient memory to allocate 889 the (de)compression state. 890*/ 891 892extern int EXPORT gzread OF((gzFile file, voidp buf, unsigned len)); 893/* 894 Reads the given number of uncompressed bytes from the compressed file. 895 If the input file was not in gzip format, gzread copies the given number 896 of bytes into the buffer. 897 gzread returns the number of uncompressed bytes actually read (0 for 898 end of file, -1 for error). */ 899 900extern int EXPORT gzwrite OF((gzFile file, const voidp buf, unsigned len)); 901/* 902 Writes the given number of uncompressed bytes into the compressed file. 903 gzwrite returns the number of uncompressed bytes actually written 904 (0 in case of error). 905*/ 906 907extern int EXPORT gzflush OF((gzFile file, int flush)); 908/* 909 Flushes all pending output into the compressed file. The parameter 910 flush is as in the deflate() function. The return value is the zlib 911 error number (see function gzerror below). gzflush returns Z_OK if 912 the flush parameter is Z_FINISH and all output could be flushed. 913 gzflush should be called only when strictly necessary because it can 914 degrade compression. 915*/ 916 917extern int EXPORT gzclose OF((gzFile file)); 918/* 919 Flushes all pending output if necessary, closes the compressed file 920 and deallocates all the (de)compression state. The return value is the zlib 921 error number (see function gzerror below). 922*/ 923 924extern const char * EXPORT gzerror OF((gzFile file, int *errnum)); 925/* 926 Returns the error message for the last error which occurred on the 927 given compressed file. errnum is set to zlib error number. If an 928 error occurred in the file system and not in the compression library, 929 errnum is set to Z_ERRNO and the application may consult errno 930 to get the exact error code. 931*/ 932 933 /* checksum functions */ 934 935/* 936 These functions are not related to compression but are exported 937 anyway because they might be useful in applications using the 938 compression library. 939*/ 940 941extern uLong EXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 942 943/* 944 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 945 return the updated checksum. If buf is NULL, this function returns 946 the required initial value for the checksum. 947 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 948 much faster. Usage example: 949 950 uLong adler = adler32(0L, Z_NULL, 0); 951 952 while (read_buffer(buffer, length) != EOF) { 953 adler = adler32(adler, buffer, length); 954 } 955 if (adler != original_adler) error(); 956*/ 957 958extern uLong EXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); 959/* 960 Update a running crc with the bytes buf[0..len-1] and return the updated 961 crc. If buf is NULL, this function returns the required initial value 962 for the crc. Pre- and post-conditioning (one's complement) is performed 963 within this function so it shouldn't be done by the application. 964 Usage example: 965 966 uLong crc = crc32(0L, Z_NULL, 0); 967 968 while (read_buffer(buffer, length) != EOF) { 969 crc = crc32(crc, buffer, length); 970 } 971 if (crc != original_crc) error(); 972*/ 973 974 975 /* various hacks, don't look :) */ 976 977/* deflateInit and inflateInit are macros to allow checking the zlib version 978 * and the compiler's view of z_stream: 979 */ 980extern int EXPORT deflateInit_ OF((z_streamp strm, int level, 981 const char *version, int stream_size)); 982extern int EXPORT inflateInit_ OF((z_streamp strm, 983 const char *version, int stream_size)); 984extern int EXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 985 int windowBits, int memLevel, int strategy, 986 const char *version, int stream_size)); 987extern int EXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 988 const char *version, int stream_size)); 989#define deflateInit(strm, level) \ 990 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) 991#define inflateInit(strm) \ 992 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) 993#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 994 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ 995 (strategy), ZLIB_VERSION, sizeof(z_stream)) 996#define inflateInit2(strm, windowBits) \ 997 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) 998 999#if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL) 1000 struct internal_state {int dummy;}; /* hack for buggy compilers */ 1001#endif 1002 1003uLongf *get_crc_table OF((void)); /* can be used by asm versions of crc32() */ 1004 1005#ifdef __cplusplus 1006} 1007#endif 1008 1009#endif /* _ZLIB_H */ 1010/* --- zlib.h */ 1011