1 /* 2 * Copyright 2003 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6 /* 7 * zlib.h -- interface of the 'zlib' general purpose compression library 8 * version 1.1.3, July 9th, 1998 9 * 10 * Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler 11 * 12 * This software is provided 'as-is', without any express or implied 13 * warranty. In no event will the authors be held liable for any damages 14 * arising from the use of this software. 15 * 16 * Permission is granted to anyone to use this software for any purpose, 17 * including commercial applications, and to alter it and redistribute it 18 * freely, subject to the following restrictions: 19 * 20 * 1. The origin of this software must not be misrepresented; you must not 21 * claim that you wrote the original software. If you use this software 22 * in a product, an acknowledgment in the product documentation would be 23 * appreciated but is not required. 24 * 2. Altered source versions must be plainly marked as such, and must not be 25 * misrepresented as being the original software. 26 * 3. This notice may not be removed or altered from any source distribution. 27 * 28 * Jean-loup Gailly Mark Adler 29 * jloup@gzip.org madler@alumni.caltech.edu 30 * 31 * The data format used by the zlib library is described by RFCs (Request for 32 * Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt 33 * (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). 34 */ 35 36 #ifndef _ZLIB_H 37 #define _ZLIB_H 38 39 #pragma ident "%Z%%M% %I% %E% SMI" 40 41 #ifdef __cplusplus 42 extern "C" { 43 #endif 44 45 #include "zconf.h" 46 47 #define ZLIB_VERSION "1.1.3" 48 49 /* 50 The 'zlib' compression library provides in-memory compression and 51 decompression functions, including integrity checks of the uncompressed 52 data. This version of the library supports only one compression method 53 (deflation) but other algorithms will be added later and will have the same 54 stream interface. 55 56 Compression can be done in a single step if the buffers are large 57 enough (for example if an input file is mmap'ed), or can be done by 58 repeated calls of the compression function. In the latter case, the 59 application must provide more input and/or consume the output 60 (providing more output space) before each call. 61 62 The library also supports reading and writing files in gzip (.gz) format 63 with an interface similar to that of stdio. 64 65 The library does not install any signal handler. The decoder checks 66 the consistency of the compressed data, so the library should never 67 crash even in case of corrupted input. 68 */ 69 70 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 71 typedef void (*free_func) OF((voidpf opaque, voidpf address)); 72 73 struct internal_state; 74 75 typedef struct z_stream_s { 76 Bytef *next_in; /* next input byte */ 77 uInt avail_in; /* number of bytes available at next_in */ 78 uLong total_in; /* total nb of input bytes read so far */ 79 80 Bytef *next_out; /* next output byte should be put there */ 81 uInt avail_out; /* remaining free space at next_out */ 82 uLong total_out; /* total nb of bytes output so far */ 83 84 char *msg; /* last error message, NULL if no error */ 85 struct internal_state FAR *state; /* not visible by applications */ 86 87 alloc_func zalloc; /* used to allocate the internal state */ 88 free_func zfree; /* used to free the internal state */ 89 voidpf opaque; /* private data object passed to zalloc and zfree */ 90 91 int data_type; /* best guess about the data type: ascii or binary */ 92 uLong adler; /* adler32 value of the uncompressed data */ 93 uLong reserved; /* reserved for future use */ 94 } z_stream; 95 96 typedef z_stream FAR *z_streamp; 97 98 /* 99 The application must update next_in and avail_in when avail_in has 100 dropped to zero. It must update next_out and avail_out when avail_out 101 has dropped to zero. The application must initialize zalloc, zfree and 102 opaque before calling the init function. All other fields are set by the 103 compression library and must not be updated by the application. 104 105 The opaque value provided by the application will be passed as the first 106 parameter for calls of zalloc and zfree. This can be useful for custom 107 memory management. The compression library attaches no meaning to the 108 opaque value. 109 110 zalloc must return Z_NULL if there is not enough memory for the object. 111 If zlib is used in a multi-threaded application, zalloc and zfree must be 112 thread safe. 113 114 On 16-bit systems, the functions zalloc and zfree must be able to allocate 115 exactly 65536 bytes, but will not be required to allocate more than this 116 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, 117 pointers returned by zalloc for objects of exactly 65536 bytes *must* 118 have their offset normalized to zero. The default allocation function 119 provided by this library ensures this (see zutil.c). To reduce memory 120 requirements and avoid any allocation of 64K objects, at the expense of 121 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). 122 123 The fields total_in and total_out can be used for statistics or 124 progress reports. After compression, total_in holds the total size of 125 the uncompressed data and may be saved for use in the decompressor 126 (particularly if the decompressor wants to decompress everything in 127 a single step). 128 */ 129 130 /* constants */ 131 132 #define Z_NO_FLUSH 0 133 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ 134 #define Z_SYNC_FLUSH 2 135 #define Z_FULL_FLUSH 3 136 #define Z_FINISH 4 137 /* Allowed flush values; see deflate() below for details */ 138 139 #define Z_OK 0 140 #define Z_STREAM_END 1 141 #define Z_NEED_DICT 2 142 #define Z_ERRNO (-1) 143 #define Z_STREAM_ERROR (-2) 144 #define Z_DATA_ERROR (-3) 145 #define Z_MEM_ERROR (-4) 146 #define Z_BUF_ERROR (-5) 147 #define Z_VERSION_ERROR (-6) 148 /* Return codes for the compression/decompression functions. Negative 149 * values are errors, positive values are used for special but normal events. 150 */ 151 152 #define Z_NO_COMPRESSION 0 153 #define Z_BEST_SPEED 1 154 #define Z_BEST_COMPRESSION 9 155 #define Z_DEFAULT_COMPRESSION (-1) 156 /* compression levels */ 157 158 #define Z_FILTERED 1 159 #define Z_HUFFMAN_ONLY 2 160 #define Z_DEFAULT_STRATEGY 0 161 /* compression strategy; see deflateInit2() below for details */ 162 163 #define Z_BINARY 0 164 #define Z_ASCII 1 165 #define Z_UNKNOWN 2 166 /* Possible values of the data_type field */ 167 168 #define Z_DEFLATED 8 169 /* The deflate compression method (the only one supported in this version) */ 170 171 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 172 173 #define zlib_version zlibVersion() 174 /* for compatibility with versions < 1.0.2 */ 175 176 /* basic functions */ 177 178 ZEXTERN const char * ZEXPORT zlibVersion OF((void)); 179 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. 180 If the first character differs, the library code actually used is 181 not compatible with the zlib.h header file used by the application. 182 This check is automatically made by deflateInit and inflateInit. 183 */ 184 185 /* 186 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); 187 188 Initializes the internal stream state for compression. The fields 189 zalloc, zfree and opaque must be initialized before by the caller. 190 If zalloc and zfree are set to Z_NULL, deflateInit updates them to 191 use default allocation functions. 192 193 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 194 1 gives best speed, 9 gives best compression, 0 gives no compression at 195 all (the input data is simply copied a block at a time). 196 Z_DEFAULT_COMPRESSION requests a default compromise between speed and 197 compression (currently equivalent to level 6). 198 199 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not 200 enough memory, Z_STREAM_ERROR if level is not a valid compression level, 201 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 202 with the version assumed by the caller (ZLIB_VERSION). 203 msg is set to null if there is no error message. deflateInit does not 204 perform any compression: this will be done by deflate(). 205 */ 206 207 208 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); 209 /* 210 deflate compresses as much data as possible, and stops when the input 211 buffer becomes empty or the output buffer becomes full. It may introduce some 212 output latency (reading input without producing any output) except when 213 forced to flush. 214 215 The detailed semantics are as follows. deflate performs one or both of the 216 following actions: 217 218 - Compress more input starting at next_in and update next_in and avail_in 219 accordingly. If not all input can be processed (because there is not 220 enough room in the output buffer), next_in and avail_in are updated and 221 processing will resume at this point for the next call of deflate(). 222 223 - Provide more output starting at next_out and update next_out and avail_out 224 accordingly. This action is forced if the parameter flush is non zero. 225 Forcing flush frequently degrades the compression ratio, so this parameter 226 should be set only when necessary (in interactive applications). 227 Some output may be provided even if flush is not set. 228 229 Before the call of deflate(), the application should ensure that at least 230 one of the actions is possible, by providing more input and/or consuming 231 more output, and updating avail_in or avail_out accordingly; avail_out 232 should never be zero before the call. The application can consume the 233 compressed output when it wants, for example when the output buffer is full 234 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK 235 and with zero avail_out, it must be called again after making room in the 236 output buffer because there might be more output pending. 237 238 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 239 flushed to the output buffer and the output is aligned on a byte boundary, so 240 that the decompressor can get all input data available so far. (In particular 241 avail_in is zero after the call if enough output space has been provided 242 before the call.) Flushing may degrade compression for some compression 243 algorithms and so it should be used only when necessary. 244 245 If flush is set to Z_FULL_FLUSH, all output is flushed as with 246 Z_SYNC_FLUSH, and the compression state is reset so that decompression can 247 restart from this point if previous compressed data has been damaged or if 248 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 249 the compression. 250 251 If deflate returns with avail_out == 0, this function must be called again 252 with the same value of the flush parameter and more output space (updated 253 avail_out), until the flush is complete (deflate returns with non-zero 254 avail_out). 255 256 If the parameter flush is set to Z_FINISH, pending input is processed, 257 pending output is flushed and deflate returns with Z_STREAM_END if there 258 was enough output space; if deflate returns with Z_OK, this function must be 259 called again with Z_FINISH and more output space (updated avail_out) but no 260 more input data, until it returns with Z_STREAM_END or an error. After 261 deflate has returned Z_STREAM_END, the only possible operations on the 262 stream are deflateReset or deflateEnd. 263 264 Z_FINISH can be used immediately after deflateInit if all the compression 265 is to be done in a single step. In this case, avail_out must be at least 266 0.1% larger than avail_in plus 12 bytes. If deflate does not return 267 Z_STREAM_END, then it must be called again as described above. 268 269 deflate() sets strm->adler to the adler32 checksum of all input read 270 so far (that is, total_in bytes). 271 272 deflate() may update data_type if it can make a good guess about 273 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered 274 binary. This field is only for information purposes and does not affect 275 the compression algorithm in any manner. 276 277 deflate() returns Z_OK if some progress has been made (more input 278 processed or more output produced), Z_STREAM_END if all input has been 279 consumed and all output has been produced (only when flush is set to 280 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 281 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible 282 (for example avail_in or avail_out was zero). 283 */ 284 285 286 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); 287 /* 288 All dynamically allocated data structures for this stream are freed. 289 This function discards any unprocessed input and does not flush any 290 pending output. 291 292 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 293 stream state was inconsistent, Z_DATA_ERROR if the stream was freed 294 prematurely (some input or output was discarded). In the error case, 295 msg may be set but then points to a static string (which must not be 296 deallocated). 297 */ 298 299 300 /* 301 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); 302 303 Initializes the internal stream state for decompression. The fields 304 next_in, avail_in, zalloc, zfree and opaque must be initialized before by 305 the caller. If next_in is not Z_NULL and avail_in is large enough (the exact 306 value depends on the compression method), inflateInit determines the 307 compression method from the zlib header and allocates all data structures 308 accordingly; otherwise the allocation will be deferred to the first call of 309 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to 310 use default allocation functions. 311 312 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 313 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 314 version assumed by the caller. msg is set to null if there is no error 315 message. inflateInit does not perform any decompression apart from reading 316 the zlib header if present: this will be done by inflate(). (So next_in and 317 avail_in may be modified, but next_out and avail_out are unchanged.) 318 */ 319 320 321 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); 322 /* 323 inflate decompresses as much data as possible, and stops when the input 324 buffer becomes empty or the output buffer becomes full. It may some 325 introduce some output latency (reading input without producing any output) 326 except when forced to flush. 327 328 The detailed semantics are as follows. inflate performs one or both of the 329 following actions: 330 331 - Decompress more input starting at next_in and update next_in and avail_in 332 accordingly. If not all input can be processed (because there is not 333 enough room in the output buffer), next_in is updated and processing 334 will resume at this point for the next call of inflate(). 335 336 - Provide more output starting at next_out and update next_out and avail_out 337 accordingly. inflate() provides as much output as possible, until there 338 is no more input data or no more space in the output buffer (see below 339 about the flush parameter). 340 341 Before the call of inflate(), the application should ensure that at least 342 one of the actions is possible, by providing more input and/or consuming 343 more output, and updating the next_* and avail_* values accordingly. 344 The application can consume the uncompressed output when it wants, for 345 example when the output buffer is full (avail_out == 0), or after each 346 call of inflate(). If inflate returns Z_OK and with zero avail_out, it 347 must be called again after making room in the output buffer because there 348 might be more output pending. 349 350 If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much 351 output as possible to the output buffer. The flushing behavior of inflate is 352 not specified for values of the flush parameter other than Z_SYNC_FLUSH 353 and Z_FINISH, but the current implementation actually flushes as much output 354 as possible anyway. 355 356 inflate() should normally be called until it returns Z_STREAM_END or an 357 error. However if all decompression is to be performed in a single step 358 (a single call of inflate), the parameter flush should be set to 359 Z_FINISH. In this case all pending input is processed and all pending 360 output is flushed; avail_out must be large enough to hold all the 361 uncompressed data. (The size of the uncompressed data may have been saved 362 by the compressor for this purpose.) The next operation on this stream must 363 be inflateEnd to deallocate the decompression state. The use of Z_FINISH 364 is never required, but can be used to inform inflate that a faster routine 365 may be used for the single inflate() call. 366 367 If a preset dictionary is needed at this point (see inflateSetDictionary 368 below), inflate sets strm-adler to the adler32 checksum of the 369 dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise 370 it sets strm->adler to the adler32 checksum of all output produced 371 so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or 372 an error code as described below. At the end of the stream, inflate() 373 checks that its computed adler32 checksum is equal to that saved by the 374 compressor and returns Z_STREAM_END only if the checksum is correct. 375 376 inflate() returns Z_OK if some progress has been made (more input processed 377 or more output produced), Z_STREAM_END if the end of the compressed data has 378 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 379 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 380 corrupted (input stream not conforming to the zlib format or incorrect 381 adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent 382 (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not 383 enough memory, Z_BUF_ERROR if no progress is possible or if there was not 384 enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR 385 case, the application may then call inflateSync to look for a good 386 compression block. 387 */ 388 389 390 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); 391 /* 392 All dynamically allocated data structures for this stream are freed. 393 This function discards any unprocessed input and does not flush any 394 pending output. 395 396 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 397 was inconsistent. In the error case, msg may be set but then points to a 398 static string (which must not be deallocated). 399 */ 400 401 /* Advanced functions */ 402 403 /* 404 The following functions are needed only in some special applications. 405 */ 406 407 /* 408 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, 409 int level, 410 int method, 411 int windowBits, 412 int memLevel, 413 int strategy)); 414 415 This is another version of deflateInit with more compression options. The 416 fields next_in, zalloc, zfree and opaque must be initialized before by 417 the caller. 418 419 The method parameter is the compression method. It must be Z_DEFLATED in 420 this version of the library. 421 422 The windowBits parameter is the base two logarithm of the window size 423 (the size of the history buffer). It should be in the range 8..15 for this 424 version of the library. Larger values of this parameter result in better 425 compression at the expense of memory usage. The default value is 15 if 426 deflateInit is used instead. 427 428 The memLevel parameter specifies how much memory should be allocated 429 for the internal compression state. memLevel=1 uses minimum memory but 430 is slow and reduces compression ratio; memLevel=9 uses maximum memory 431 for optimal speed. The default value is 8. See zconf.h for total memory 432 usage as a function of windowBits and memLevel. 433 434 The strategy parameter is used to tune the compression algorithm. Use the 435 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 436 filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no 437 string match). Filtered data consists mostly of small values with a 438 somewhat random distribution. In this case, the compression algorithm is 439 tuned to compress them better. The effect of Z_FILTERED is to force more 440 Huffman coding and less string matching; it is somewhat intermediate 441 between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects 442 the compression ratio but not the correctness of the compressed output even 443 if it is not set appropriately. 444 445 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 446 memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid 447 method). msg is set to null if there is no error message. deflateInit2 does 448 not perform any compression: this will be done by deflate(). 449 */ 450 451 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, 452 const Bytef *dictionary, 453 uInt dictLength)); 454 /* 455 Initializes the compression dictionary from the given byte sequence 456 without producing any compressed output. This function must be called 457 immediately after deflateInit, deflateInit2 or deflateReset, before any 458 call of deflate. The compressor and decompressor must use exactly the same 459 dictionary (see inflateSetDictionary). 460 461 The dictionary should consist of strings (byte sequences) that are likely 462 to be encountered later in the data to be compressed, with the most commonly 463 used strings preferably put towards the end of the dictionary. Using a 464 dictionary is most useful when the data to be compressed is short and can be 465 predicted with good accuracy; the data can then be compressed better than 466 with the default empty dictionary. 467 468 Depending on the size of the compression data structures selected by 469 deflateInit or deflateInit2, a part of the dictionary may in effect be 470 discarded, for example if the dictionary is larger than the window size in 471 deflate or deflate2. Thus the strings most likely to be useful should be 472 put at the end of the dictionary, not at the front. 473 474 Upon return of this function, strm->adler is set to the Adler32 value 475 of the dictionary; the decompressor may later use this value to determine 476 which dictionary has been used by the compressor. (The Adler32 value 477 applies to the whole dictionary even if only a subset of the dictionary is 478 actually used by the compressor.) 479 480 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 481 parameter is invalid (such as NULL dictionary) or the stream state is 482 inconsistent (for example if deflate has already been called for this stream 483 or if the compression method is bsort). deflateSetDictionary does not 484 perform any compression: this will be done by deflate(). 485 */ 486 487 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, 488 z_streamp source)); 489 /* 490 Sets the destination stream as a complete copy of the source stream. 491 492 This function can be useful when several compression strategies will be 493 tried, for example when there are several ways of pre-processing the input 494 data with a filter. The streams that will be discarded should then be freed 495 by calling deflateEnd. Note that deflateCopy duplicates the internal 496 compression state which can be quite large, so this strategy is slow and 497 can consume lots of memory. 498 499 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 500 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 501 (such as zalloc being NULL). msg is left unchanged in both source and 502 destination. 503 */ 504 505 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); 506 /* 507 This function is equivalent to deflateEnd followed by deflateInit, 508 but does not free and reallocate all the internal compression state. 509 The stream will keep the same compression level and any other attributes 510 that may have been set by deflateInit2. 511 512 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 513 stream state was inconsistent (such as zalloc or state being NULL). 514 */ 515 516 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, 517 int level, 518 int strategy)); 519 /* 520 Dynamically update the compression level and compression strategy. The 521 interpretation of level and strategy is as in deflateInit2. This can be 522 used to switch between compression and straight copy of the input data, or 523 to switch to a different kind of input data requiring a different 524 strategy. If the compression level is changed, the input available so far 525 is compressed with the old level (and may be flushed); the new level will 526 take effect only at the next call of deflate(). 527 528 Before the call of deflateParams, the stream state must be set as for 529 a call of deflate(), since the currently available input may have to 530 be compressed and flushed. In particular, strm->avail_out must be non-zero. 531 532 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source 533 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR 534 if strm->avail_out was zero. 535 */ 536 537 /* 538 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, 539 int windowBits)); 540 541 This is another version of inflateInit with an extra parameter. The 542 fields next_in, avail_in, zalloc, zfree and opaque must be initialized 543 before by the caller. 544 545 The windowBits parameter is the base two logarithm of the maximum window 546 size (the size of the history buffer). It should be in the range 8..15 for 547 this version of the library. The default value is 15 if inflateInit is used 548 instead. If a compressed stream with a larger window size is given as 549 input, inflate() will return with the error code Z_DATA_ERROR instead of 550 trying to allocate a larger window. 551 552 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 553 memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative 554 memLevel). msg is set to null if there is no error message. inflateInit2 555 does not perform any decompression apart from reading the zlib header if 556 present: this will be done by inflate(). (So next_in and avail_in may be 557 modified, but next_out and avail_out are unchanged.) 558 */ 559 560 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, 561 const Bytef *dictionary, 562 uInt dictLength)); 563 /* 564 Initializes the decompression dictionary from the given uncompressed byte 565 sequence. This function must be called immediately after a call of inflate 566 if this call returned Z_NEED_DICT. The dictionary chosen by the compressor 567 can be determined from the Adler32 value returned by this call of 568 inflate. The compressor and decompressor must use exactly the same 569 dictionary (see deflateSetDictionary). 570 571 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 572 parameter is invalid (such as NULL dictionary) or the stream state is 573 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 574 expected one (incorrect Adler32 value). inflateSetDictionary does not 575 perform any decompression: this will be done by subsequent calls of 576 inflate(). 577 */ 578 579 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); 580 /* 581 Skips invalid compressed data until a full flush point (see above the 582 description of deflate with Z_FULL_FLUSH) can be found, or until all 583 available input is skipped. No output is provided. 584 585 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR 586 if no more input was provided, Z_DATA_ERROR if no flush point has been found, 587 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success 588 case, the application may save the current current value of total_in which 589 indicates where valid compressed data was found. In the error case, the 590 application may repeatedly call inflateSync, providing more input each time, 591 until success or end of the input data. 592 */ 593 594 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); 595 /* 596 This function is equivalent to inflateEnd followed by inflateInit, 597 but does not free and reallocate all the internal decompression state. 598 The stream will keep attributes that may have been set by inflateInit2. 599 600 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 601 stream state was inconsistent (such as zalloc or state being NULL). 602 */ 603 604 /* checksum functions */ 605 606 /* 607 These functions are not related to compression but are exported 608 anyway because they might be useful in applications using the 609 compression library. 610 */ 611 612 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 613 614 /* 615 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 616 return the updated checksum. If buf is NULL, this function returns 617 the required initial value for the checksum. 618 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 619 much faster. Usage example: 620 621 uLong adler = adler32(0L, Z_NULL, 0); 622 623 while (read_buffer(buffer, length) != EOF) { 624 adler = adler32(adler, buffer, length); 625 } 626 if (adler != original_adler) error(); 627 */ 628 629 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); 630 /* 631 Update a running crc with the bytes buf[0..len-1] and return the updated 632 crc. If buf is NULL, this function returns the required initial value 633 for the crc. Pre- and post-conditioning (one's complement) is performed 634 within this function so it shouldn't be done by the application. 635 Usage example: 636 637 uLong crc = crc32(0L, Z_NULL, 0); 638 639 while (read_buffer(buffer, length) != EOF) { 640 crc = crc32(crc, buffer, length); 641 } 642 if (crc != original_crc) error(); 643 */ 644 645 646 /* various hacks, don't look :) */ 647 648 /* deflateInit and inflateInit are macros to allow checking the zlib version 649 * and the compiler's view of z_stream: 650 */ 651 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, 652 const char *version, int stream_size)); 653 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, 654 const char *version, int stream_size)); 655 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 656 int windowBits, int memLevel, 657 int strategy, const char *version, 658 int stream_size)); 659 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 660 const char *version, int stream_size)); 661 #define deflateInit(strm, level) \ 662 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) 663 #define inflateInit(strm) \ 664 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) 665 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 666 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ 667 (strategy), ZLIB_VERSION, sizeof(z_stream)) 668 #define inflateInit2(strm, windowBits) \ 669 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) 670 671 672 ZEXTERN const char * ZEXPORT zError OF((int err)); 673 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z)); 674 ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void)); 675 676 #ifdef __cplusplus 677 } 678 #endif 679 680 #endif /* _ZLIB_H */ 681