1/* zlib.h -- interface of the 'zlib' general purpose compression library 2 version 1.1.3, July 9th, 1998 3 4 Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler 5 6 This software is provided 'as-is', without any express or implied 7 warranty. In no event will the authors be held liable for any damages 8 arising from the use of this software. 9 10 Permission is granted to anyone to use this software for any purpose, 11 including commercial applications, and to alter it and redistribute it 12 freely, subject to the following restrictions: 13 14 1. The origin of this software must not be misrepresented; you must not 15 claim that you wrote the original software. If you use this software 16 in a product, an acknowledgment in the product documentation would be 17 appreciated but is not required. 18 2. Altered source versions must be plainly marked as such, and must not be 19 misrepresented as being the original software. 20 3. This notice may not be removed or altered from any source distribution. 21 22 Jean-loup Gailly Mark Adler 23 jloup@gzip.org madler@alumni.caltech.edu 24 25 26 The data format used by the zlib library is described by RFCs (Request for 27 Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt 28 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). 29*/ 30 31#ifndef _ZLIB_H 32#define _ZLIB_H 33 34#include "zconf.h" 35 36#ifdef __cplusplus 37extern "C" { 38#endif 39 40#define ZLIB_VERSION "1.1.3" 41 42/* 43 The 'zlib' compression library provides in-memory compression and 44 decompression functions, including integrity checks of the uncompressed 45 data. This version of the library supports only one compression method 46 (deflation) but other algorithms will be added later and will have the same 47 stream interface. 48 49 Compression can be done in a single step if the buffers are large 50 enough (for example if an input file is mmap'ed), or can be done by 51 repeated calls of the compression function. In the latter case, the 52 application must provide more input and/or consume the output 53 (providing more output space) before each call. 54 55 The library also supports reading and writing files in gzip (.gz) format 56 with an interface similar to that of stdio. 57 58 The library does not install any signal handler. The decoder checks 59 the consistency of the compressed data, so the library should never 60 crash even in case of corrupted input. 61*/ 62 63typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 64typedef void (*free_func) OF((voidpf opaque, voidpf address)); 65 66struct internal_state; 67 68typedef struct z_stream_s { 69 Bytef *next_in; /* next input byte */ 70 uInt avail_in; /* number of bytes available at next_in */ 71 uLong total_in; /* total nb of input bytes read so far */ 72 73 Bytef *next_out; /* next output byte should be put there */ 74 uInt avail_out; /* remaining free space at next_out */ 75 uLong total_out; /* total nb of bytes output so far */ 76 77 char *msg; /* last error message, NULL if no error */ 78 struct internal_state FAR *state; /* not visible by applications */ 79 80 alloc_func zalloc; /* used to allocate the internal state */ 81 free_func zfree; /* used to free the internal state */ 82 voidpf opaque; /* private data object passed to zalloc and zfree */ 83 84 int data_type; /* best guess about the data type: ascii or binary */ 85 uLong adler; /* adler32 value of the uncompressed data */ 86 uLong reserved; /* reserved for future use */ 87} z_stream; 88 89typedef z_stream FAR *z_streamp; 90 91/* 92 The application must update next_in and avail_in when avail_in has 93 dropped to zero. It must update next_out and avail_out when avail_out 94 has dropped to zero. The application must initialize zalloc, zfree and 95 opaque before calling the init function. All other fields are set by the 96 compression library and must not be updated by the application. 97 98 The opaque value provided by the application will be passed as the first 99 parameter for calls of zalloc and zfree. This can be useful for custom 100 memory management. The compression library attaches no meaning to the 101 opaque value. 102 103 zalloc must return Z_NULL if there is not enough memory for the object. 104 If zlib is used in a multi-threaded application, zalloc and zfree must be 105 thread safe. 106 107 On 16-bit systems, the functions zalloc and zfree must be able to allocate 108 exactly 65536 bytes, but will not be required to allocate more than this 109 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, 110 pointers returned by zalloc for objects of exactly 65536 bytes *must* 111 have their offset normalized to zero. The default allocation function 112 provided by this library ensures this (see zutil.c). To reduce memory 113 requirements and avoid any allocation of 64K objects, at the expense of 114 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). 115 116 The fields total_in and total_out can be used for statistics or 117 progress reports. After compression, total_in holds the total size of 118 the uncompressed data and may be saved for use in the decompressor 119 (particularly if the decompressor wants to decompress everything in 120 a single step). 121*/ 122 123 /* constants */ 124 125#define Z_NO_FLUSH 0 126#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ 127#define Z_SYNC_FLUSH 2 128#define Z_FULL_FLUSH 3 129#define Z_FINISH 4 130/* Allowed flush values; see deflate() below for details */ 131 132#define Z_OK 0 133#define Z_STREAM_END 1 134#define Z_NEED_DICT 2 135#define Z_ERRNO (-1) 136#define Z_STREAM_ERROR (-2) 137#define Z_DATA_ERROR (-3) 138#define Z_MEM_ERROR (-4) 139#define Z_BUF_ERROR (-5) 140#define Z_VERSION_ERROR (-6) 141/* Return codes for the compression/decompression functions. Negative 142 * values are errors, positive values are used for special but normal events. 143 */ 144 145#define Z_NO_COMPRESSION 0 146#define Z_BEST_SPEED 1 147#define Z_BEST_COMPRESSION 9 148#define Z_DEFAULT_COMPRESSION (-1) 149/* compression levels */ 150 151#define Z_FILTERED 1 152#define Z_HUFFMAN_ONLY 2 153#define Z_DEFAULT_STRATEGY 0 154/* compression strategy; see deflateInit2() below for details */ 155 156#define Z_BINARY 0 157#define Z_ASCII 1 158#define Z_UNKNOWN 2 159/* Possible values of the data_type field */ 160 161#define Z_DEFLATED 8 162/* The deflate compression method (the only one supported in this version) */ 163 164#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 165 166#define zlib_version zlibVersion() 167/* for compatibility with versions < 1.0.2 */ 168 169 /* basic functions */ 170 171ZEXTERN const char * ZEXPORT zlibVersion OF((void)); 172/* The application can compare zlibVersion and ZLIB_VERSION for consistency. 173 If the first character differs, the library code actually used is 174 not compatible with the zlib.h header file used by the application. 175 This check is automatically made by deflateInit and inflateInit. 176 */ 177 178/* 179ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); 180 181 Initializes the internal stream state for compression. The fields 182 zalloc, zfree and opaque must be initialized before by the caller. 183 If zalloc and zfree are set to Z_NULL, deflateInit updates them to 184 use default allocation functions. 185 186 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 187 1 gives best speed, 9 gives best compression, 0 gives no compression at 188 all (the input data is simply copied a block at a time). 189 Z_DEFAULT_COMPRESSION requests a default compromise between speed and 190 compression (currently equivalent to level 6). 191 192 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not 193 enough memory, Z_STREAM_ERROR if level is not a valid compression level, 194 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 195 with the version assumed by the caller (ZLIB_VERSION). 196 msg is set to null if there is no error message. deflateInit does not 197 perform any compression: this will be done by deflate(). 198*/ 199 200 201ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); 202/* 203 deflate compresses as much data as possible, and stops when the input 204 buffer becomes empty or the output buffer becomes full. It may introduce some 205 output latency (reading input without producing any output) except when 206 forced to flush. 207 208 The detailed semantics are as follows. deflate performs one or both of the 209 following actions: 210 211 - Compress more input starting at next_in and update next_in and avail_in 212 accordingly. If not all input can be processed (because there is not 213 enough room in the output buffer), next_in and avail_in are updated and 214 processing will resume at this point for the next call of deflate(). 215 216 - Provide more output starting at next_out and update next_out and avail_out 217 accordingly. This action is forced if the parameter flush is non zero. 218 Forcing flush frequently degrades the compression ratio, so this parameter 219 should be set only when necessary (in interactive applications). 220 Some output may be provided even if flush is not set. 221 222 Before the call of deflate(), the application should ensure that at least 223 one of the actions is possible, by providing more input and/or consuming 224 more output, and updating avail_in or avail_out accordingly; avail_out 225 should never be zero before the call. The application can consume the 226 compressed output when it wants, for example when the output buffer is full 227 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK 228 and with zero avail_out, it must be called again after making room in the 229 output buffer because there might be more output pending. 230 231 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 232 flushed to the output buffer and the output is aligned on a byte boundary, so 233 that the decompressor can get all input data available so far. (In particular 234 avail_in is zero after the call if enough output space has been provided 235 before the call.) Flushing may degrade compression for some compression 236 algorithms and so it should be used only when necessary. 237 238 If flush is set to Z_FULL_FLUSH, all output is flushed as with 239 Z_SYNC_FLUSH, and the compression state is reset so that decompression can 240 restart from this point if previous compressed data has been damaged or if 241 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 242 the compression. 243 244 If deflate returns with avail_out == 0, this function must be called again 245 with the same value of the flush parameter and more output space (updated 246 avail_out), until the flush is complete (deflate returns with non-zero 247 avail_out). 248 249 If the parameter flush is set to Z_FINISH, pending input is processed, 250 pending output is flushed and deflate returns with Z_STREAM_END if there 251 was enough output space; if deflate returns with Z_OK, this function must be 252 called again with Z_FINISH and more output space (updated avail_out) but no 253 more input data, until it returns with Z_STREAM_END or an error. After 254 deflate has returned Z_STREAM_END, the only possible operations on the 255 stream are deflateReset or deflateEnd. 256 257 Z_FINISH can be used immediately after deflateInit if all the compression 258 is to be done in a single step. In this case, avail_out must be at least 259 0.1% larger than avail_in plus 12 bytes. If deflate does not return 260 Z_STREAM_END, then it must be called again as described above. 261 262 deflate() sets strm->adler to the adler32 checksum of all input read 263 so far (that is, total_in bytes). 264 265 deflate() may update data_type if it can make a good guess about 266 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered 267 binary. This field is only for information purposes and does not affect 268 the compression algorithm in any manner. 269 270 deflate() returns Z_OK if some progress has been made (more input 271 processed or more output produced), Z_STREAM_END if all input has been 272 consumed and all output has been produced (only when flush is set to 273 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 274 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible 275 (for example avail_in or avail_out was zero). 276*/ 277 278 279ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); 280/* 281 All dynamically allocated data structures for this stream are freed. 282 This function discards any unprocessed input and does not flush any 283 pending output. 284 285 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 286 stream state was inconsistent, Z_DATA_ERROR if the stream was freed 287 prematurely (some input or output was discarded). In the error case, 288 msg may be set but then points to a static string (which must not be 289 deallocated). 290*/ 291 292 293/* 294ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); 295 296 Initializes the internal stream state for decompression. The fields 297 next_in, avail_in, zalloc, zfree and opaque must be initialized before by 298 the caller. If next_in is not Z_NULL and avail_in is large enough (the exact 299 value depends on the compression method), inflateInit determines the 300 compression method from the zlib header and allocates all data structures 301 accordingly; otherwise the allocation will be deferred to the first call of 302 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to 303 use default allocation functions. 304 305 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 306 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 307 version assumed by the caller. msg is set to null if there is no error 308 message. inflateInit does not perform any decompression apart from reading 309 the zlib header if present: this will be done by inflate(). (So next_in and 310 avail_in may be modified, but next_out and avail_out are unchanged.) 311*/ 312 313 314ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); 315/* 316 inflate decompresses as much data as possible, and stops when the input 317 buffer becomes empty or the output buffer becomes full. It may some 318 introduce some output latency (reading input without producing any output) 319 except when forced to flush. 320 321 The detailed semantics are as follows. inflate performs one or both of the 322 following actions: 323 324 - Decompress more input starting at next_in and update next_in and avail_in 325 accordingly. If not all input can be processed (because there is not 326 enough room in the output buffer), next_in is updated and processing 327 will resume at this point for the next call of inflate(). 328 329 - Provide more output starting at next_out and update next_out and avail_out 330 accordingly. inflate() provides as much output as possible, until there 331 is no more input data or no more space in the output buffer (see below 332 about the flush parameter). 333 334 Before the call of inflate(), the application should ensure that at least 335 one of the actions is possible, by providing more input and/or consuming 336 more output, and updating the next_* and avail_* values accordingly. 337 The application can consume the uncompressed output when it wants, for 338 example when the output buffer is full (avail_out == 0), or after each 339 call of inflate(). If inflate returns Z_OK and with zero avail_out, it 340 must be called again after making room in the output buffer because there 341 might be more output pending. 342 343 If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much 344 output as possible to the output buffer. The flushing behavior of inflate is 345 not specified for values of the flush parameter other than Z_SYNC_FLUSH 346 and Z_FINISH, but the current implementation actually flushes as much output 347 as possible anyway. 348 349 inflate() should normally be called until it returns Z_STREAM_END or an 350 error. However if all decompression is to be performed in a single step 351 (a single call of inflate), the parameter flush should be set to 352 Z_FINISH. In this case all pending input is processed and all pending 353 output is flushed; avail_out must be large enough to hold all the 354 uncompressed data. (The size of the uncompressed data may have been saved 355 by the compressor for this purpose.) The next operation on this stream must 356 be inflateEnd to deallocate the decompression state. The use of Z_FINISH 357 is never required, but can be used to inform inflate that a faster routine 358 may be used for the single inflate() call. 359 360 If a preset dictionary is needed at this point (see inflateSetDictionary 361 below), inflate sets strm-adler to the adler32 checksum of the 362 dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise 363 it sets strm->adler to the adler32 checksum of all output produced 364 so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or 365 an error code as described below. At the end of the stream, inflate() 366 checks that its computed adler32 checksum is equal to that saved by the 367 compressor and returns Z_STREAM_END only if the checksum is correct. 368 369 inflate() returns Z_OK if some progress has been made (more input processed 370 or more output produced), Z_STREAM_END if the end of the compressed data has 371 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 372 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 373 corrupted (input stream not conforming to the zlib format or incorrect 374 adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent 375 (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not 376 enough memory, Z_BUF_ERROR if no progress is possible or if there was not 377 enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR 378 case, the application may then call inflateSync to look for a good 379 compression block. 380*/ 381 382 383ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); 384/* 385 All dynamically allocated data structures for this stream are freed. 386 This function discards any unprocessed input and does not flush any 387 pending output. 388 389 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 390 was inconsistent. In the error case, msg may be set but then points to a 391 static string (which must not be deallocated). 392*/ 393 394 /* Advanced functions */ 395 396/* 397 The following functions are needed only in some special applications. 398*/ 399 400/* 401ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, 402 int level, 403 int method, 404 int windowBits, 405 int memLevel, 406 int strategy)); 407 408 This is another version of deflateInit with more compression options. The 409 fields next_in, zalloc, zfree and opaque must be initialized before by 410 the caller. 411 412 The method parameter is the compression method. It must be Z_DEFLATED in 413 this version of the library. 414 415 The windowBits parameter is the base two logarithm of the window size 416 (the size of the history buffer). It should be in the range 8..15 for this 417 version of the library. Larger values of this parameter result in better 418 compression at the expense of memory usage. The default value is 15 if 419 deflateInit is used instead. 420 421 The memLevel parameter specifies how much memory should be allocated 422 for the internal compression state. memLevel=1 uses minimum memory but 423 is slow and reduces compression ratio; memLevel=9 uses maximum memory 424 for optimal speed. The default value is 8. See zconf.h for total memory 425 usage as a function of windowBits and memLevel. 426 427 The strategy parameter is used to tune the compression algorithm. Use the 428 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 429 filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no 430 string match). Filtered data consists mostly of small values with a 431 somewhat random distribution. In this case, the compression algorithm is 432 tuned to compress them better. The effect of Z_FILTERED is to force more 433 Huffman coding and less string matching; it is somewhat intermediate 434 between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects 435 the compression ratio but not the correctness of the compressed output even 436 if it is not set appropriately. 437 438 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 439 memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid 440 method). msg is set to null if there is no error message. deflateInit2 does 441 not perform any compression: this will be done by deflate(). 442*/ 443 444ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, 445 const Bytef *dictionary, 446 uInt dictLength)); 447/* 448 Initializes the compression dictionary from the given byte sequence 449 without producing any compressed output. This function must be called 450 immediately after deflateInit, deflateInit2 or deflateReset, before any 451 call of deflate. The compressor and decompressor must use exactly the same 452 dictionary (see inflateSetDictionary). 453 454 The dictionary should consist of strings (byte sequences) that are likely 455 to be encountered later in the data to be compressed, with the most commonly 456 used strings preferably put towards the end of the dictionary. Using a 457 dictionary is most useful when the data to be compressed is short and can be 458 predicted with good accuracy; the data can then be compressed better than 459 with the default empty dictionary. 460 461 Depending on the size of the compression data structures selected by 462 deflateInit or deflateInit2, a part of the dictionary may in effect be 463 discarded, for example if the dictionary is larger than the window size in 464 deflate or deflate2. Thus the strings most likely to be useful should be 465 put at the end of the dictionary, not at the front. 466 467 Upon return of this function, strm->adler is set to the Adler32 value 468 of the dictionary; the decompressor may later use this value to determine 469 which dictionary has been used by the compressor. (The Adler32 value 470 applies to the whole dictionary even if only a subset of the dictionary is 471 actually used by the compressor.) 472 473 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 474 parameter is invalid (such as NULL dictionary) or the stream state is 475 inconsistent (for example if deflate has already been called for this stream 476 or if the compression method is bsort). deflateSetDictionary does not 477 perform any compression: this will be done by deflate(). 478*/ 479 480ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, 481 z_streamp source)); 482/* 483 Sets the destination stream as a complete copy of the source stream. 484 485 This function can be useful when several compression strategies will be 486 tried, for example when there are several ways of pre-processing the input 487 data with a filter. The streams that will be discarded should then be freed 488 by calling deflateEnd. Note that deflateCopy duplicates the internal 489 compression state which can be quite large, so this strategy is slow and 490 can consume lots of memory. 491 492 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 493 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 494 (such as zalloc being NULL). msg is left unchanged in both source and 495 destination. 496*/ 497 498ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); 499/* 500 This function is equivalent to deflateEnd followed by deflateInit, 501 but does not free and reallocate all the internal compression state. 502 The stream will keep the same compression level and any other attributes 503 that may have been set by deflateInit2. 504 505 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 506 stream state was inconsistent (such as zalloc or state being NULL). 507*/ 508 509ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, 510 int level, 511 int strategy)); 512/* 513 Dynamically update the compression level and compression strategy. The 514 interpretation of level and strategy is as in deflateInit2. This can be 515 used to switch between compression and straight copy of the input data, or 516 to switch to a different kind of input data requiring a different 517 strategy. If the compression level is changed, the input available so far 518 is compressed with the old level (and may be flushed); the new level will 519 take effect only at the next call of deflate(). 520 521 Before the call of deflateParams, the stream state must be set as for 522 a call of deflate(), since the currently available input may have to 523 be compressed and flushed. In particular, strm->avail_out must be non-zero. 524 525 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source 526 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR 527 if strm->avail_out was zero. 528*/ 529 530/* 531ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, 532 int windowBits)); 533 534 This is another version of inflateInit with an extra parameter. The 535 fields next_in, avail_in, zalloc, zfree and opaque must be initialized 536 before by the caller. 537 538 The windowBits parameter is the base two logarithm of the maximum window 539 size (the size of the history buffer). It should be in the range 8..15 for 540 this version of the library. The default value is 15 if inflateInit is used 541 instead. If a compressed stream with a larger window size is given as 542 input, inflate() will return with the error code Z_DATA_ERROR instead of 543 trying to allocate a larger window. 544 545 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 546 memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative 547 memLevel). msg is set to null if there is no error message. inflateInit2 548 does not perform any decompression apart from reading the zlib header if 549 present: this will be done by inflate(). (So next_in and avail_in may be 550 modified, but next_out and avail_out are unchanged.) 551*/ 552 553ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, 554 const Bytef *dictionary, 555 uInt dictLength)); 556/* 557 Initializes the decompression dictionary from the given uncompressed byte 558 sequence. This function must be called immediately after a call of inflate 559 if this call returned Z_NEED_DICT. The dictionary chosen by the compressor 560 can be determined from the Adler32 value returned by this call of 561 inflate. The compressor and decompressor must use exactly the same 562 dictionary (see deflateSetDictionary). 563 564 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 565 parameter is invalid (such as NULL dictionary) or the stream state is 566 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 567 expected one (incorrect Adler32 value). inflateSetDictionary does not 568 perform any decompression: this will be done by subsequent calls of 569 inflate(). 570*/ 571 572ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); 573/* 574 Skips invalid compressed data until a full flush point (see above the 575 description of deflate with Z_FULL_FLUSH) can be found, or until all 576 available input is skipped. No output is provided. 577 578 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR 579 if no more input was provided, Z_DATA_ERROR if no flush point has been found, 580 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success 581 case, the application may save the current current value of total_in which 582 indicates where valid compressed data was found. In the error case, the 583 application may repeatedly call inflateSync, providing more input each time, 584 until success or end of the input data. 585*/ 586 587ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); 588/* 589 This function is equivalent to inflateEnd followed by inflateInit, 590 but does not free and reallocate all the internal decompression state. 591 The stream will keep attributes that may have been set by inflateInit2. 592 593 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 594 stream state was inconsistent (such as zalloc or state being NULL). 595*/ 596 597 598 /* utility functions */ 599 600/* 601 The following utility functions are implemented on top of the 602 basic stream-oriented functions. To simplify the interface, some 603 default options are assumed (compression level and memory usage, 604 standard memory allocation functions). The source code of these 605 utility functions can easily be modified if you need special options. 606*/ 607 608ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, 609 const Bytef *source, uLong sourceLen)); 610/* 611 Compresses the source buffer into the destination buffer. sourceLen is 612 the byte length of the source buffer. Upon entry, destLen is the total 613 size of the destination buffer, which must be at least 0.1% larger than 614 sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the 615 compressed buffer. 616 This function can be used to compress a whole file at once if the 617 input file is mmap'ed. 618 compress returns Z_OK if success, Z_MEM_ERROR if there was not 619 enough memory, Z_BUF_ERROR if there was not enough room in the output 620 buffer. 621*/ 622 623ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, 624 const Bytef *source, uLong sourceLen, 625 int level)); 626/* 627 Compresses the source buffer into the destination buffer. The level 628 parameter has the same meaning as in deflateInit. sourceLen is the byte 629 length of the source buffer. Upon entry, destLen is the total size of the 630 destination buffer, which must be at least 0.1% larger than sourceLen plus 631 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. 632 633 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 634 memory, Z_BUF_ERROR if there was not enough room in the output buffer, 635 Z_STREAM_ERROR if the level parameter is invalid. 636*/ 637 638ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, 639 const Bytef *source, uLong sourceLen)); 640/* 641 Decompresses the source buffer into the destination buffer. sourceLen is 642 the byte length of the source buffer. Upon entry, destLen is the total 643 size of the destination buffer, which must be large enough to hold the 644 entire uncompressed data. (The size of the uncompressed data must have 645 been saved previously by the compressor and transmitted to the decompressor 646 by some mechanism outside the scope of this compression library.) 647 Upon exit, destLen is the actual size of the compressed buffer. 648 This function can be used to decompress a whole file at once if the 649 input file is mmap'ed. 650 651 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 652 enough memory, Z_BUF_ERROR if there was not enough room in the output 653 buffer, or Z_DATA_ERROR if the input data was corrupted. 654*/ 655 656 657typedef voidp gzFile; 658 659ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); 660/* 661 Opens a gzip (.gz) file for reading or writing. The mode parameter 662 is as in fopen ("rb" or "wb") but can also include a compression level 663 ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for 664 Huffman only compression as in "wb1h". (See the description 665 of deflateInit2 for more information about the strategy parameter.) 666 667 gzopen can be used to read a file which is not in gzip format; in this 668 case gzread will directly read from the file without decompression. 669 670 gzopen returns NULL if the file could not be opened or if there was 671 insufficient memory to allocate the (de)compression state; errno 672 can be checked to distinguish the two cases (if errno is zero, the 673 zlib error is Z_MEM_ERROR). */ 674 675ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); 676/* 677 gzdopen() associates a gzFile with the file descriptor fd. File 678 descriptors are obtained from calls like open, dup, creat, pipe or 679 fileno (in the file has been previously opened with fopen). 680 The mode parameter is as in gzopen. 681 The next call of gzclose on the returned gzFile will also close the 682 file descriptor fd, just like fclose(fdopen(fd), mode) closes the file 683 descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode). 684 gzdopen returns NULL if there was insufficient memory to allocate 685 the (de)compression state. 686*/ 687 688ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); 689/* 690 Dynamically update the compression level or strategy. See the description 691 of deflateInit2 for the meaning of these parameters. 692 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not 693 opened for writing. 694*/ 695 696ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); 697/* 698 Reads the given number of uncompressed bytes from the compressed file. 699 If the input file was not in gzip format, gzread copies the given number 700 of bytes into the buffer. 701 gzread returns the number of uncompressed bytes actually read (0 for 702 end of file, -1 for error). */ 703 704ZEXTERN int ZEXPORT gzwrite OF((gzFile file, 705 const voidp buf, unsigned len)); 706/* 707 Writes the given number of uncompressed bytes into the compressed file. 708 gzwrite returns the number of uncompressed bytes actually written 709 (0 in case of error). 710*/ 711 712ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); 713/* 714 Converts, formats, and writes the args to the compressed file under 715 control of the format string, as in fprintf. gzprintf returns the number of 716 uncompressed bytes actually written (0 in case of error). 717*/ 718 719ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); 720/* 721 Writes the given null-terminated string to the compressed file, excluding 722 the terminating null character. 723 gzputs returns the number of characters written, or -1 in case of error. 724*/ 725 726ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); 727/* 728 Reads bytes from the compressed file until len-1 characters are read, or 729 a newline character is read and transferred to buf, or an end-of-file 730 condition is encountered. The string is then terminated with a null 731 character. 732 gzgets returns buf, or Z_NULL in case of error. 733*/ 734 735ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); 736/* 737 Writes c, converted to an unsigned char, into the compressed file. 738 gzputc returns the value that was written, or -1 in case of error. 739*/ 740 741ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); 742/* 743 Reads one byte from the compressed file. gzgetc returns this byte 744 or -1 in case of end of file or error. 745*/ 746 747ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); 748/* 749 Flushes all pending output into the compressed file. The parameter 750 flush is as in the deflate() function. The return value is the zlib 751 error number (see function gzerror below). gzflush returns Z_OK if 752 the flush parameter is Z_FINISH and all output could be flushed. 753 gzflush should be called only when strictly necessary because it can 754 degrade compression. 755*/ 756 757ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, 758 z_off_t offset, int whence)); 759/* 760 Sets the starting position for the next gzread or gzwrite on the 761 given compressed file. The offset represents a number of bytes in the 762 uncompressed data stream. The whence parameter is defined as in lseek(2); 763 the value SEEK_END is not supported. 764 If the file is opened for reading, this function is emulated but can be 765 extremely slow. If the file is opened for writing, only forward seeks are 766 supported; gzseek then compresses a sequence of zeroes up to the new 767 starting position. 768 769 gzseek returns the resulting offset location as measured in bytes from 770 the beginning of the uncompressed stream, or -1 in case of error, in 771 particular if the file is opened for writing and the new starting position 772 would be before the current position. 773*/ 774 775ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); 776/* 777 Rewinds the given file. This function is supported only for reading. 778 779 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) 780*/ 781 782ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); 783/* 784 Returns the starting position for the next gzread or gzwrite on the 785 given compressed file. This position represents a number of bytes in the 786 uncompressed data stream. 787 788 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) 789*/ 790 791ZEXTERN int ZEXPORT gzeof OF((gzFile file)); 792/* 793 Returns 1 when EOF has previously been detected reading the given 794 input stream, otherwise zero. 795*/ 796 797ZEXTERN int ZEXPORT gzclose OF((gzFile file)); 798/* 799 Flushes all pending output if necessary, closes the compressed file 800 and deallocates all the (de)compression state. The return value is the zlib 801 error number (see function gzerror below). 802*/ 803 804ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); 805/* 806 Returns the error message for the last error which occurred on the 807 given compressed file. errnum is set to zlib error number. If an 808 error occurred in the file system and not in the compression library, 809 errnum is set to Z_ERRNO and the application may consult errno 810 to get the exact error code. 811*/ 812 813 /* checksum functions */ 814 815/* 816 These functions are not related to compression but are exported 817 anyway because they might be useful in applications using the 818 compression library. 819*/ 820 821ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 822 823/* 824 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 825 return the updated checksum. If buf is NULL, this function returns 826 the required initial value for the checksum. 827 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 828 much faster. Usage example: 829 830 uLong adler = adler32(0L, Z_NULL, 0); 831 832 while (read_buffer(buffer, length) != EOF) { 833 adler = adler32(adler, buffer, length); 834 } 835 if (adler != original_adler) error(); 836*/ 837 838ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); 839/* 840 Update a running crc with the bytes buf[0..len-1] and return the updated 841 crc. If buf is NULL, this function returns the required initial value 842 for the crc. Pre- and post-conditioning (one's complement) is performed 843 within this function so it shouldn't be done by the application. 844 Usage example: 845 846 uLong crc = crc32(0L, Z_NULL, 0); 847 848 while (read_buffer(buffer, length) != EOF) { 849 crc = crc32(crc, buffer, length); 850 } 851 if (crc != original_crc) error(); 852*/ 853 854 855 /* various hacks, don't look :) */ 856 857/* deflateInit and inflateInit are macros to allow checking the zlib version 858 * and the compiler's view of z_stream: 859 */ 860ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, 861 const char *version, int stream_size)); 862ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, 863 const char *version, int stream_size)); 864ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 865 int windowBits, int memLevel, 866 int strategy, const char *version, 867 int stream_size)); 868ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 869 const char *version, int stream_size)); 870#define deflateInit(strm, level) \ 871 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) 872#define inflateInit(strm) \ 873 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) 874#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 875 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ 876 (strategy), ZLIB_VERSION, sizeof(z_stream)) 877#define inflateInit2(strm, windowBits) \ 878 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) 879 880 881#if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL) 882 struct internal_state {int dummy;}; /* hack for buggy compilers */ 883#endif 884 885ZEXTERN const char * ZEXPORT zError OF((int err)); 886ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z)); 887ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void)); 888 889#ifdef __cplusplus 890} 891#endif 892 893#endif /* _ZLIB_H */ 894