1/* zlib.h -- interface of the 'zlib' general purpose compression library 2 version 1.2.8, April 28th, 2013 3 4 Copyright (C) 1995-2013 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 http://tools.ietf.org/html/rfc1950 28 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). 29*/ 30 31#ifndef ZLIB_H 32#define ZLIB_H 33 34#define deflate_copyright FPDFAPI_deflate_copyright 35#define adler32 FPDFAPI_adler32 36#define compress2 FPDFAPI_compress2 37#define compress FPDFAPI_compress 38#define compressBound FPDFAPI_compressBound 39#define get_crc_table FPDFAPI_get_crc_table 40#define crc32 FPDFAPI_crc32 41#define deflateInit_ FPDFAPI_deflateInit_ 42#define deflateInit2_ FPDFAPI_deflateInit2_ 43#define deflateSetDictionary FPDFAPI_deflateSetDictionary 44#define deflateReset FPDFAPI_deflateReset 45#define deflatePending FPDFAPI_deflatePending 46#define deflatePrime FPDFAPI_deflatePrime 47#define deflateParams FPDFAPI_deflateParams 48#define deflateBound FPDFAPI_deflateBound 49#define deflateSetHeader FPDFAPI_deflateSetHeader 50#define deflateTune FPDFAPI_deflateTune 51#define deflate FPDFAPI_deflate 52#define deflateEnd FPDFAPI_deflateEnd 53#define deflateCopy FPDFAPI_deflateCopy 54#define inflateBackInit_ FPDFAPI_inflateBackInit_ 55#define inflateBack FPDFAPI_inflateBack 56#define inflateBackEnd FPDFAPI_inflateBackEnd 57#define inflateReset FPDFAPI_inflateReset 58#define inflateInit2_ FPDFAPI_inflateInit2_ 59#define inflateInit_ FPDFAPI_inflateInit_ 60#define inflate FPDFAPI_inflate 61#define inflateEnd FPDFAPI_inflateEnd 62#define inflateSetDictionary FPDFAPI_inflateSetDictionary 63#define inflateSync FPDFAPI_inflateSync 64#define inflateSyncPoint FPDFAPI_inflateSyncPoint 65#define inflateCopy FPDFAPI_inflateCopy 66#define uncompress FPDFAPI_uncompress 67#define zlibVersion FPDFAPI_zlibVersion 68#define zlibCompileFlags FPDFAPI_zlibCompileFlags 69#define zError FPDFAPI_zError 70#define z_errmsg FPDFAPI_z_errmsg 71#define zcfree FPDFAPI_zcfree 72#define zcalloc FPDFAPI_zcalloc 73#define inflate_fast FPDFAPI_inflate_fast 74#define inflate_table FPDFAPI_inflate_table 75#define inflate_copyright FPDFAPI_inflate_copyright 76#define _length_code FPDFAPI_length_code 77#define _tr_flush_block FPDFAPI_tr_flush_block 78#define _dist_code FPDFAPI_dist_code 79#define _tr_stored_block FPDFAPI_tr_stored_block 80#define _tr_init FPDFAPI_tr_init 81#define _tr_align FPDFAPI_tr_align 82#define _tr_tally FPDFAPI_tr_tally 83#define _tr_flush_bits FPDFAPI_tr_flush_bits 84#define adler32_combine FPDFAPI_adler32_combine 85#define inflatePrime FPDFAPI_inflatePrime 86#define inflateGetDictionary FPDFAPI_inflateGetDictionary 87#define inflateGetHeader FPDFAPI_inflateGetHeader 88#define crc32_combine FPDFAPI_crc32_combine 89#define inflateReset2 FPDFAPI_inflateReset2 90#define inflateUndermine FPDFAPI_inflateUndermine 91#define inflateMark FPDFAPI_inflateMark 92#define adler32_combine64 FPDFAPI_adler32_combine64 93#define inflateResetKeep FPDFAPI_inflateResetKeep 94#define deflateResetKeep FPDFAPI_deflateResetKeep 95 96#include "zconf.h" 97 98/* Sunliang.Liu 20100908 sync the config to the old revision. NO_GZIP */ 99#define NO_GZIP /* XYQ */ 100 101#ifdef __cplusplus 102extern "C" { 103#endif 104 105#define ZLIB_VERSION "1.2.8" 106#define ZLIB_VERNUM 0x1280 107#define ZLIB_VER_MAJOR 1 108#define ZLIB_VER_MINOR 2 109#define ZLIB_VER_REVISION 8 110#define ZLIB_VER_SUBREVISION 0 111 112/* 113 The 'zlib' compression library provides in-memory compression and 114 decompression functions, including integrity checks of the uncompressed data. 115 This version of the library supports only one compression method (deflation) 116 but other algorithms will be added later and will have the same stream 117 interface. 118 119 Compression can be done in a single step if the buffers are large enough, 120 or can be done by repeated calls of the compression function. In the latter 121 case, the application must provide more input and/or consume the output 122 (providing more output space) before each call. 123 124 The compressed data format used by default by the in-memory functions is 125 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 126 around a deflate stream, which is itself documented in RFC 1951. 127 128 The library also supports reading and writing files in gzip (.gz) format 129 with an interface similar to that of stdio using the functions that start 130 with "gz". The gzip format is different from the zlib format. gzip is a 131 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. 132 133 This library can optionally read and write gzip streams in memory as well. 134 135 The zlib format was designed to be compact and fast for use in memory 136 and on communications channels. The gzip format was designed for single- 137 file compression on file systems, has a larger header than zlib to maintain 138 directory information, and uses a different, slower check method than zlib. 139 140 The library does not install any signal handler. The decoder checks 141 the consistency of the compressed data, so the library should never crash 142 even in case of corrupted input. 143*/ 144 145typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 146typedef void (*free_func) OF((voidpf opaque, voidpf address)); 147 148struct internal_state; 149 150typedef struct z_stream_s { 151 z_const Bytef *next_in; /* next input byte */ 152 uInt avail_in; /* number of bytes available at next_in */ 153 uLong total_in; /* total number of input bytes read so far */ 154 155 Bytef *next_out; /* next output byte should be put there */ 156 uInt avail_out; /* remaining free space at next_out */ 157 uLong total_out; /* total number of bytes output so far */ 158 159 z_const char *msg; /* last error message, NULL if no error */ 160 struct internal_state FAR *state; /* not visible by applications */ 161 162 alloc_func zalloc; /* used to allocate the internal state */ 163 free_func zfree; /* used to free the internal state */ 164 voidpf opaque; /* private data object passed to zalloc and zfree */ 165 166 int data_type; /* best guess about the data type: binary or text */ 167 uLong adler; /* adler32 value of the uncompressed data */ 168 uLong reserved; /* reserved for future use */ 169} z_stream; 170 171typedef z_stream FAR *z_streamp; 172 173/* 174 gzip header information passed to and from zlib routines. See RFC 1952 175 for more details on the meanings of these fields. 176*/ 177typedef struct gz_header_s { 178 int text; /* true if compressed data believed to be text */ 179 uLong time; /* modification time */ 180 int xflags; /* extra flags (not used when writing a gzip file) */ 181 int os; /* operating system */ 182 Bytef *extra; /* pointer to extra field or Z_NULL if none */ 183 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ 184 uInt extra_max; /* space at extra (only when reading header) */ 185 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ 186 uInt name_max; /* space at name (only when reading header) */ 187 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ 188 uInt comm_max; /* space at comment (only when reading header) */ 189 int hcrc; /* true if there was or will be a header crc */ 190 int done; /* true when done reading gzip header (not used 191 when writing a gzip file) */ 192} gz_header; 193 194typedef gz_header FAR *gz_headerp; 195 196/* 197 The application must update next_in and avail_in when avail_in has dropped 198 to zero. It must update next_out and avail_out when avail_out has dropped 199 to zero. The application must initialize zalloc, zfree and opaque before 200 calling the init function. All other fields are set by the compression 201 library and must not be updated by the application. 202 203 The opaque value provided by the application will be passed as the first 204 parameter for calls of zalloc and zfree. This can be useful for custom 205 memory management. The compression library attaches no meaning to the 206 opaque value. 207 208 zalloc must return Z_NULL if there is not enough memory for the object. 209 If zlib is used in a multi-threaded application, zalloc and zfree must be 210 thread safe. 211 212 On 16-bit systems, the functions zalloc and zfree must be able to allocate 213 exactly 65536 bytes, but will not be required to allocate more than this if 214 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers 215 returned by zalloc for objects of exactly 65536 bytes *must* have their 216 offset normalized to zero. The default allocation function provided by this 217 library ensures this (see zutil.c). To reduce memory requirements and avoid 218 any allocation of 64K objects, at the expense of compression ratio, compile 219 the library with -DMAX_WBITS=14 (see zconf.h). 220 221 The fields total_in and total_out can be used for statistics or progress 222 reports. After compression, total_in holds the total size of the 223 uncompressed data and may be saved for use in the decompressor (particularly 224 if the decompressor wants to decompress everything in a single step). 225*/ 226 227 /* constants */ 228 229#define Z_NO_FLUSH 0 230#define Z_PARTIAL_FLUSH 1 231#define Z_SYNC_FLUSH 2 232#define Z_FULL_FLUSH 3 233#define Z_FINISH 4 234#define Z_BLOCK 5 235#define Z_TREES 6 236/* Allowed flush values; see deflate() and inflate() below for details */ 237 238#define Z_OK 0 239#define Z_STREAM_END 1 240#define Z_NEED_DICT 2 241#define Z_ERRNO (-1) 242#define Z_STREAM_ERROR (-2) 243#define Z_DATA_ERROR (-3) 244#define Z_MEM_ERROR (-4) 245#define Z_BUF_ERROR (-5) 246#define Z_VERSION_ERROR (-6) 247/* Return codes for the compression/decompression functions. Negative values 248 * are errors, positive values are used for special but normal events. 249 */ 250 251#define Z_NO_COMPRESSION 0 252#define Z_BEST_SPEED 1 253#define Z_BEST_COMPRESSION 9 254#define Z_DEFAULT_COMPRESSION (-1) 255/* compression levels */ 256 257#define Z_FILTERED 1 258#define Z_HUFFMAN_ONLY 2 259#define Z_RLE 3 260#define Z_FIXED 4 261#define Z_DEFAULT_STRATEGY 0 262/* compression strategy; see deflateInit2() below for details */ 263 264#define Z_BINARY 0 265#define Z_TEXT 1 266#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ 267#define Z_UNKNOWN 2 268/* Possible values of the data_type field (though see inflate()) */ 269 270#define Z_DEFLATED 8 271/* The deflate compression method (the only one supported in this version) */ 272 273#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 274 275#define zlib_version zlibVersion() 276/* for compatibility with versions < 1.0.2 */ 277 278 279 /* basic functions */ 280 281ZEXTERN const char * ZEXPORT zlibVersion OF((void)); 282/* The application can compare zlibVersion and ZLIB_VERSION for consistency. 283 If the first character differs, the library code actually used is not 284 compatible with the zlib.h header file used by the application. This check 285 is automatically made by deflateInit and inflateInit. 286 */ 287 288/* 289ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); 290 291 Initializes the internal stream state for compression. The fields 292 zalloc, zfree and opaque must be initialized before by the caller. If 293 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default 294 allocation functions. 295 296 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 297 1 gives best speed, 9 gives best compression, 0 gives no compression at all 298 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION 299 requests a default compromise between speed and compression (currently 300 equivalent to level 6). 301 302 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 303 memory, Z_STREAM_ERROR if level is not a valid compression level, or 304 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 305 with the version assumed by the caller (ZLIB_VERSION). msg is set to null 306 if there is no error message. deflateInit does not perform any compression: 307 this will be done by deflate(). 308*/ 309 310 311ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); 312/* 313 deflate compresses as much data as possible, and stops when the input 314 buffer becomes empty or the output buffer becomes full. It may introduce 315 some output latency (reading input without producing any output) except when 316 forced to flush. 317 318 The detailed semantics are as follows. deflate performs one or both of the 319 following actions: 320 321 - Compress more input starting at next_in and update next_in and avail_in 322 accordingly. If not all input can be processed (because there is not 323 enough room in the output buffer), next_in and avail_in are updated and 324 processing will resume at this point for the next call of deflate(). 325 326 - Provide more output starting at next_out and update next_out and avail_out 327 accordingly. This action is forced if the parameter flush is non zero. 328 Forcing flush frequently degrades the compression ratio, so this parameter 329 should be set only when necessary (in interactive applications). Some 330 output may be provided even if flush is not set. 331 332 Before the call of deflate(), the application should ensure that at least 333 one of the actions is possible, by providing more input and/or consuming more 334 output, and updating avail_in or avail_out accordingly; avail_out should 335 never be zero before the call. The application can consume the compressed 336 output when it wants, for example when the output buffer is full (avail_out 337 == 0), or after each call of deflate(). If deflate returns Z_OK and with 338 zero avail_out, it must be called again after making room in the output 339 buffer because there might be more output pending. 340 341 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to 342 decide how much data to accumulate before producing output, in order to 343 maximize compression. 344 345 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 346 flushed to the output buffer and the output is aligned on a byte boundary, so 347 that the decompressor can get all input data available so far. (In 348 particular avail_in is zero after the call if enough output space has been 349 provided before the call.) Flushing may degrade compression for some 350 compression algorithms and so it should be used only when necessary. This 351 completes the current deflate block and follows it with an empty stored block 352 that is three bits plus filler bits to the next byte, followed by four bytes 353 (00 00 ff ff). 354 355 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the 356 output buffer, but the output is not aligned to a byte boundary. All of the 357 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. 358 This completes the current deflate block and follows it with an empty fixed 359 codes block that is 10 bits long. This assures that enough bytes are output 360 in order for the decompressor to finish the block before the empty fixed code 361 block. 362 363 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as 364 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to 365 seven bits of the current block are held to be written as the next byte after 366 the next deflate block is completed. In this case, the decompressor may not 367 be provided enough bits at this point in order to complete decompression of 368 the data provided so far to the compressor. It may need to wait for the next 369 block to be emitted. This is for advanced applications that need to control 370 the emission of deflate blocks. 371 372 If flush is set to Z_FULL_FLUSH, all output is flushed as with 373 Z_SYNC_FLUSH, and the compression state is reset so that decompression can 374 restart from this point if previous compressed data has been damaged or if 375 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 376 compression. 377 378 If deflate returns with avail_out == 0, this function must be called again 379 with the same value of the flush parameter and more output space (updated 380 avail_out), until the flush is complete (deflate returns with non-zero 381 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that 382 avail_out is greater than six to avoid repeated flush markers due to 383 avail_out == 0 on return. 384 385 If the parameter flush is set to Z_FINISH, pending input is processed, 386 pending output is flushed and deflate returns with Z_STREAM_END if there was 387 enough output space; if deflate returns with Z_OK, this function must be 388 called again with Z_FINISH and more output space (updated avail_out) but no 389 more input data, until it returns with Z_STREAM_END or an error. After 390 deflate has returned Z_STREAM_END, the only possible operations on the stream 391 are deflateReset or deflateEnd. 392 393 Z_FINISH can be used immediately after deflateInit if all the compression 394 is to be done in a single step. In this case, avail_out must be at least the 395 value returned by deflateBound (see below). Then deflate is guaranteed to 396 return Z_STREAM_END. If not enough output space is provided, deflate will 397 not return Z_STREAM_END, and it must be called again as described above. 398 399 deflate() sets strm->adler to the adler32 checksum of all input read 400 so far (that is, total_in bytes). 401 402 deflate() may update strm->data_type if it can make a good guess about 403 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered 404 binary. This field is only for information purposes and does not affect the 405 compression algorithm in any manner. 406 407 deflate() returns Z_OK if some progress has been made (more input 408 processed or more output produced), Z_STREAM_END if all input has been 409 consumed and all output has been produced (only when flush is set to 410 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 411 if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible 412 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not 413 fatal, and deflate() can be called again with more input and more output 414 space to continue compressing. 415*/ 416 417 418ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); 419/* 420 All dynamically allocated data structures for this stream are freed. 421 This function discards any unprocessed input and does not flush any pending 422 output. 423 424 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 425 stream state was inconsistent, Z_DATA_ERROR if the stream was freed 426 prematurely (some input or output was discarded). In the error case, msg 427 may be set but then points to a static string (which must not be 428 deallocated). 429*/ 430 431 432/* 433ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); 434 435 Initializes the internal stream state for decompression. The fields 436 next_in, avail_in, zalloc, zfree and opaque must be initialized before by 437 the caller. If next_in is not Z_NULL and avail_in is large enough (the 438 exact value depends on the compression method), inflateInit determines the 439 compression method from the zlib header and allocates all data structures 440 accordingly; otherwise the allocation will be deferred to the first call of 441 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to 442 use default allocation functions. 443 444 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 445 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 446 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 447 invalid, such as a null pointer to the structure. msg is set to null if 448 there is no error message. inflateInit does not perform any decompression 449 apart from possibly reading the zlib header if present: actual decompression 450 will be done by inflate(). (So next_in and avail_in may be modified, but 451 next_out and avail_out are unused and unchanged.) The current implementation 452 of inflateInit() does not process any header information -- that is deferred 453 until inflate() is called. 454*/ 455 456 457ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); 458/* 459 inflate decompresses as much data as possible, and stops when the input 460 buffer becomes empty or the output buffer becomes full. It may introduce 461 some output latency (reading input without producing any output) except when 462 forced to flush. 463 464 The detailed semantics are as follows. inflate performs one or both of the 465 following actions: 466 467 - Decompress more input starting at next_in and update next_in and avail_in 468 accordingly. If not all input can be processed (because there is not 469 enough room in the output buffer), next_in is updated and processing will 470 resume at this point for the next call of inflate(). 471 472 - Provide more output starting at next_out and update next_out and avail_out 473 accordingly. inflate() provides as much output as possible, until there is 474 no more input data or no more space in the output buffer (see below about 475 the flush parameter). 476 477 Before the call of inflate(), the application should ensure that at least 478 one of the actions is possible, by providing more input and/or consuming more 479 output, and updating the next_* and avail_* values accordingly. The 480 application can consume the uncompressed output when it wants, for example 481 when the output buffer is full (avail_out == 0), or after each call of 482 inflate(). If inflate returns Z_OK and with zero avail_out, it must be 483 called again after making room in the output buffer because there might be 484 more output pending. 485 486 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, 487 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much 488 output as possible to the output buffer. Z_BLOCK requests that inflate() 489 stop if and when it gets to the next deflate block boundary. When decoding 490 the zlib or gzip format, this will cause inflate() to return immediately 491 after the header and before the first block. When doing a raw inflate, 492 inflate() will go ahead and process the first block, and will return when it 493 gets to the end of that block, or when it runs out of data. 494 495 The Z_BLOCK option assists in appending to or combining deflate streams. 496 Also to assist in this, on return inflate() will set strm->data_type to the 497 number of unused bits in the last byte taken from strm->next_in, plus 64 if 498 inflate() is currently decoding the last block in the deflate stream, plus 499 128 if inflate() returned immediately after decoding an end-of-block code or 500 decoding the complete header up to just before the first byte of the deflate 501 stream. The end-of-block will not be indicated until all of the uncompressed 502 data from that block has been written to strm->next_out. The number of 503 unused bits may in general be greater than seven, except when bit 7 of 504 data_type is set, in which case the number of unused bits will be less than 505 eight. data_type is set as noted here every time inflate() returns for all 506 flush options, and so can be used to determine the amount of currently 507 consumed input in bits. 508 509 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the 510 end of each deflate block header is reached, before any actual data in that 511 block is decoded. This allows the caller to determine the length of the 512 deflate block header for later use in random access within a deflate block. 513 256 is added to the value of strm->data_type when inflate() returns 514 immediately after reaching the end of the deflate block header. 515 516 inflate() should normally be called until it returns Z_STREAM_END or an 517 error. However if all decompression is to be performed in a single step (a 518 single call of inflate), the parameter flush should be set to Z_FINISH. In 519 this case all pending input is processed and all pending output is flushed; 520 avail_out must be large enough to hold all of the uncompressed data for the 521 operation to complete. (The size of the uncompressed data may have been 522 saved by the compressor for this purpose.) The use of Z_FINISH is not 523 required to perform an inflation in one step. However it may be used to 524 inform inflate that a faster approach can be used for the single inflate() 525 call. Z_FINISH also informs inflate to not maintain a sliding window if the 526 stream completes, which reduces inflate's memory footprint. If the stream 527 does not complete, either because not all of the stream is provided or not 528 enough output space is provided, then a sliding window will be allocated and 529 inflate() can be called again to continue the operation as if Z_NO_FLUSH had 530 been used. 531 532 In this implementation, inflate() always flushes as much output as 533 possible to the output buffer, and always uses the faster approach on the 534 first call. So the effects of the flush parameter in this implementation are 535 on the return value of inflate() as noted below, when inflate() returns early 536 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of 537 memory for a sliding window when Z_FINISH is used. 538 539 If a preset dictionary is needed after this call (see inflateSetDictionary 540 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary 541 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 542 strm->adler to the Adler-32 checksum of all output produced so far (that is, 543 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 544 below. At the end of the stream, inflate() checks that its computed adler32 545 checksum is equal to that saved by the compressor and returns Z_STREAM_END 546 only if the checksum is correct. 547 548 inflate() can decompress and check either zlib-wrapped or gzip-wrapped 549 deflate data. The header type is detected automatically, if requested when 550 initializing with inflateInit2(). Any information contained in the gzip 551 header is not retained, so applications that need that information should 552 instead use raw inflate, see inflateInit2() below, or inflateBack() and 553 perform their own processing of the gzip header and trailer. When processing 554 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output 555 producted so far. The CRC-32 is checked against the gzip trailer. 556 557 inflate() returns Z_OK if some progress has been made (more input processed 558 or more output produced), Z_STREAM_END if the end of the compressed data has 559 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 560 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 561 corrupted (input stream not conforming to the zlib format or incorrect check 562 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example 563 next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory, 564 Z_BUF_ERROR if no progress is possible or if there was not enough room in the 565 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 566 inflate() can be called again with more input and more output space to 567 continue decompressing. If Z_DATA_ERROR is returned, the application may 568 then call inflateSync() to look for a good compression block if a partial 569 recovery of the data is desired. 570*/ 571 572 573ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); 574/* 575 All dynamically allocated data structures for this stream are freed. 576 This function discards any unprocessed input and does not flush any pending 577 output. 578 579 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 580 was inconsistent. In the error case, msg may be set but then points to a 581 static string (which must not be deallocated). 582*/ 583 584 585 /* Advanced functions */ 586 587/* 588 The following functions are needed only in some special applications. 589*/ 590 591/* 592ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, 593 int level, 594 int method, 595 int windowBits, 596 int memLevel, 597 int strategy)); 598 599 This is another version of deflateInit with more compression options. The 600 fields next_in, zalloc, zfree and opaque must be initialized before by the 601 caller. 602 603 The method parameter is the compression method. It must be Z_DEFLATED in 604 this version of the library. 605 606 The windowBits parameter is the base two logarithm of the window size 607 (the size of the history buffer). It should be in the range 8..15 for this 608 version of the library. Larger values of this parameter result in better 609 compression at the expense of memory usage. The default value is 15 if 610 deflateInit is used instead. 611 612 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits 613 determines the window size. deflate() will then generate raw deflate data 614 with no zlib header or trailer, and will not compute an adler32 check value. 615 616 windowBits can also be greater than 15 for optional gzip encoding. Add 617 16 to windowBits to write a simple gzip header and trailer around the 618 compressed data instead of a zlib wrapper. The gzip header will have no 619 file name, no extra data, no comment, no modification time (set to zero), no 620 header crc, and the operating system will be set to 255 (unknown). If a 621 gzip stream is being written, strm->adler is a crc32 instead of an adler32. 622 623 The memLevel parameter specifies how much memory should be allocated 624 for the internal compression state. memLevel=1 uses minimum memory but is 625 slow and reduces compression ratio; memLevel=9 uses maximum memory for 626 optimal speed. The default value is 8. See zconf.h for total memory usage 627 as a function of windowBits and memLevel. 628 629 The strategy parameter is used to tune the compression algorithm. Use the 630 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 631 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no 632 string match), or Z_RLE to limit match distances to one (run-length 633 encoding). Filtered data consists mostly of small values with a somewhat 634 random distribution. In this case, the compression algorithm is tuned to 635 compress them better. The effect of Z_FILTERED is to force more Huffman 636 coding and less string matching; it is somewhat intermediate between 637 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as 638 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The 639 strategy parameter only affects the compression ratio but not the 640 correctness of the compressed output even if it is not set appropriately. 641 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler 642 decoder for special applications. 643 644 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 645 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid 646 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is 647 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is 648 set to null if there is no error message. deflateInit2 does not perform any 649 compression: this will be done by deflate(). 650*/ 651 652ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, 653 const Bytef *dictionary, 654 uInt dictLength)); 655/* 656 Initializes the compression dictionary from the given byte sequence 657 without producing any compressed output. When using the zlib format, this 658 function must be called immediately after deflateInit, deflateInit2 or 659 deflateReset, and before any call of deflate. When doing raw deflate, this 660 function must be called either before any call of deflate, or immediately 661 after the completion of a deflate block, i.e. after all input has been 662 consumed and all output has been delivered when using any of the flush 663 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The 664 compressor and decompressor must use exactly the same dictionary (see 665 inflateSetDictionary). 666 667 The dictionary should consist of strings (byte sequences) that are likely 668 to be encountered later in the data to be compressed, with the most commonly 669 used strings preferably put towards the end of the dictionary. Using a 670 dictionary is most useful when the data to be compressed is short and can be 671 predicted with good accuracy; the data can then be compressed better than 672 with the default empty dictionary. 673 674 Depending on the size of the compression data structures selected by 675 deflateInit or deflateInit2, a part of the dictionary may in effect be 676 discarded, for example if the dictionary is larger than the window size 677 provided in deflateInit or deflateInit2. Thus the strings most likely to be 678 useful should be put at the end of the dictionary, not at the front. In 679 addition, the current implementation of deflate will use at most the window 680 size minus 262 bytes of the provided dictionary. 681 682 Upon return of this function, strm->adler is set to the adler32 value 683 of the dictionary; the decompressor may later use this value to determine 684 which dictionary has been used by the compressor. (The adler32 value 685 applies to the whole dictionary even if only a subset of the dictionary is 686 actually used by the compressor.) If a raw deflate was requested, then the 687 adler32 value is not computed and strm->adler is not set. 688 689 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 690 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is 691 inconsistent (for example if deflate has already been called for this stream 692 or if not at a block boundary for raw deflate). deflateSetDictionary does 693 not perform any compression: this will be done by deflate(). 694*/ 695 696ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, 697 z_streamp source)); 698/* 699 Sets the destination stream as a complete copy of the source stream. 700 701 This function can be useful when several compression strategies will be 702 tried, for example when there are several ways of pre-processing the input 703 data with a filter. The streams that will be discarded should then be freed 704 by calling deflateEnd. Note that deflateCopy duplicates the internal 705 compression state which can be quite large, so this strategy is slow and can 706 consume lots of memory. 707 708 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 709 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 710 (such as zalloc being Z_NULL). msg is left unchanged in both source and 711 destination. 712*/ 713 714ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); 715/* 716 This function is equivalent to deflateEnd followed by deflateInit, 717 but does not free and reallocate all the internal compression state. The 718 stream will keep the same compression level and any other attributes that 719 may have been set by deflateInit2. 720 721 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 722 stream state was inconsistent (such as zalloc or state being Z_NULL). 723*/ 724 725ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, 726 int level, 727 int strategy)); 728/* 729 Dynamically update the compression level and compression strategy. The 730 interpretation of level and strategy is as in deflateInit2. This can be 731 used to switch between compression and straight copy of the input data, or 732 to switch to a different kind of input data requiring a different strategy. 733 If the compression level is changed, the input available so far is 734 compressed with the old level (and may be flushed); the new level will take 735 effect only at the next call of deflate(). 736 737 Before the call of deflateParams, the stream state must be set as for 738 a call of deflate(), since the currently available input may have to be 739 compressed and flushed. In particular, strm->avail_out must be non-zero. 740 741 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source 742 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if 743 strm->avail_out was zero. 744*/ 745 746ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, 747 int good_length, 748 int max_lazy, 749 int nice_length, 750 int max_chain)); 751/* 752 Fine tune deflate's internal compression parameters. This should only be 753 used by someone who understands the algorithm used by zlib's deflate for 754 searching for the best matching string, and even then only by the most 755 fanatic optimizer trying to squeeze out the last compressed bit for their 756 specific input data. Read the deflate.c source code for the meaning of the 757 max_lazy, good_length, nice_length, and max_chain parameters. 758 759 deflateTune() can be called after deflateInit() or deflateInit2(), and 760 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. 761 */ 762 763ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, 764 uLong sourceLen)); 765/* 766 deflateBound() returns an upper bound on the compressed size after 767 deflation of sourceLen bytes. It must be called after deflateInit() or 768 deflateInit2(), and after deflateSetHeader(), if used. This would be used 769 to allocate an output buffer for deflation in a single pass, and so would be 770 called before deflate(). If that first deflate() call is provided the 771 sourceLen input bytes, an output buffer allocated to the size returned by 772 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed 773 to return Z_STREAM_END. Note that it is possible for the compressed size to 774 be larger than the value returned by deflateBound() if flush options other 775 than Z_FINISH or Z_NO_FLUSH are used. 776*/ 777 778ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm, 779 unsigned *pending, 780 int *bits)); 781/* 782 deflatePending() returns the number of bytes and bits of output that have 783 been generated, but not yet provided in the available output. The bytes not 784 provided would be due to the available output space having being consumed. 785 The number of bits of output not provided are between 0 and 7, where they 786 await more bits to join them in order to fill out a full byte. If pending 787 or bits are Z_NULL, then those values are not set. 788 789 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source 790 stream state was inconsistent. 791 */ 792 793ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, 794 int bits, 795 int value)); 796/* 797 deflatePrime() inserts bits in the deflate output stream. The intent 798 is that this function is used to start off the deflate output with the bits 799 leftover from a previous deflate stream when appending to it. As such, this 800 function can only be used for raw deflate, and must be used before the first 801 deflate() call after a deflateInit2() or deflateReset(). bits must be less 802 than or equal to 16, and that many of the least significant bits of value 803 will be inserted in the output. 804 805 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough 806 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the 807 source stream state was inconsistent. 808*/ 809 810ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, 811 gz_headerp head)); 812/* 813 deflateSetHeader() provides gzip header information for when a gzip 814 stream is requested by deflateInit2(). deflateSetHeader() may be called 815 after deflateInit2() or deflateReset() and before the first call of 816 deflate(). The text, time, os, extra field, name, and comment information 817 in the provided gz_header structure are written to the gzip header (xflag is 818 ignored -- the extra flags are set according to the compression level). The 819 caller must assure that, if not Z_NULL, name and comment are terminated with 820 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are 821 available there. If hcrc is true, a gzip header crc is included. Note that 822 the current versions of the command-line version of gzip (up through version 823 1.3.x) do not support header crc's, and will report that it is a "multi-part 824 gzip file" and give up. 825 826 If deflateSetHeader is not used, the default gzip header has text false, 827 the time set to zero, and os set to 255, with no extra, name, or comment 828 fields. The gzip header is returned to the default state by deflateReset(). 829 830 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 831 stream state was inconsistent. 832*/ 833 834/* 835ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, 836 int windowBits)); 837 838 This is another version of inflateInit with an extra parameter. The 839 fields next_in, avail_in, zalloc, zfree and opaque must be initialized 840 before by the caller. 841 842 The windowBits parameter is the base two logarithm of the maximum window 843 size (the size of the history buffer). It should be in the range 8..15 for 844 this version of the library. The default value is 15 if inflateInit is used 845 instead. windowBits must be greater than or equal to the windowBits value 846 provided to deflateInit2() while compressing, or it must be equal to 15 if 847 deflateInit2() was not used. If a compressed stream with a larger window 848 size is given as input, inflate() will return with the error code 849 Z_DATA_ERROR instead of trying to allocate a larger window. 850 851 windowBits can also be zero to request that inflate use the window size in 852 the zlib header of the compressed stream. 853 854 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits 855 determines the window size. inflate() will then process raw deflate data, 856 not looking for a zlib or gzip header, not generating a check value, and not 857 looking for any check values for comparison at the end of the stream. This 858 is for use with other formats that use the deflate compressed data format 859 such as zip. Those formats provide their own check values. If a custom 860 format is developed using the raw deflate format for compressed data, it is 861 recommended that a check value such as an adler32 or a crc32 be applied to 862 the uncompressed data as is done in the zlib, gzip, and zip formats. For 863 most applications, the zlib format should be used as is. Note that comments 864 above on the use in deflateInit2() applies to the magnitude of windowBits. 865 866 windowBits can also be greater than 15 for optional gzip decoding. Add 867 32 to windowBits to enable zlib and gzip decoding with automatic header 868 detection, or add 16 to decode only the gzip format (the zlib format will 869 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a 870 crc32 instead of an adler32. 871 872 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 873 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 874 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 875 invalid, such as a null pointer to the structure. msg is set to null if 876 there is no error message. inflateInit2 does not perform any decompression 877 apart from possibly reading the zlib header if present: actual decompression 878 will be done by inflate(). (So next_in and avail_in may be modified, but 879 next_out and avail_out are unused and unchanged.) The current implementation 880 of inflateInit2() does not process any header information -- that is 881 deferred until inflate() is called. 882*/ 883 884ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, 885 const Bytef *dictionary, 886 uInt dictLength)); 887/* 888 Initializes the decompression dictionary from the given uncompressed byte 889 sequence. This function must be called immediately after a call of inflate, 890 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor 891 can be determined from the adler32 value returned by that call of inflate. 892 The compressor and decompressor must use exactly the same dictionary (see 893 deflateSetDictionary). For raw inflate, this function can be called at any 894 time to set the dictionary. If the provided dictionary is smaller than the 895 window and there is already data in the window, then the provided dictionary 896 will amend what's there. The application must insure that the dictionary 897 that was used for compression is provided. 898 899 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 900 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is 901 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 902 expected one (incorrect adler32 value). inflateSetDictionary does not 903 perform any decompression: this will be done by subsequent calls of 904 inflate(). 905*/ 906 907ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm, 908 Bytef *dictionary, 909 uInt *dictLength)); 910/* 911 Returns the sliding dictionary being maintained by inflate. dictLength is 912 set to the number of bytes in the dictionary, and that many bytes are copied 913 to dictionary. dictionary must have enough space, where 32768 bytes is 914 always enough. If inflateGetDictionary() is called with dictionary equal to 915 Z_NULL, then only the dictionary length is returned, and nothing is copied. 916 Similary, if dictLength is Z_NULL, then it is not set. 917 918 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the 919 stream state is inconsistent. 920*/ 921 922ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); 923/* 924 Skips invalid compressed data until a possible full flush point (see above 925 for the description of deflate with Z_FULL_FLUSH) can be found, or until all 926 available input is skipped. No output is provided. 927 928 inflateSync searches for a 00 00 FF FF pattern in the compressed data. 929 All full flush points have this pattern, but not all occurrences of this 930 pattern are full flush points. 931 932 inflateSync returns Z_OK if a possible full flush point has been found, 933 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point 934 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. 935 In the success case, the application may save the current current value of 936 total_in which indicates where valid compressed data was found. In the 937 error case, the application may repeatedly call inflateSync, providing more 938 input each time, until success or end of the input data. 939*/ 940 941ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, 942 z_streamp source)); 943/* 944 Sets the destination stream as a complete copy of the source stream. 945 946 This function can be useful when randomly accessing a large stream. The 947 first pass through the stream can periodically record the inflate state, 948 allowing restarting inflate at those points when randomly accessing the 949 stream. 950 951 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 952 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 953 (such as zalloc being Z_NULL). msg is left unchanged in both source and 954 destination. 955*/ 956 957ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); 958/* 959 This function is equivalent to inflateEnd followed by inflateInit, 960 but does not free and reallocate all the internal decompression state. The 961 stream will keep attributes that may have been set by inflateInit2. 962 963 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 964 stream state was inconsistent (such as zalloc or state being Z_NULL). 965*/ 966 967ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, 968 int windowBits)); 969/* 970 This function is the same as inflateReset, but it also permits changing 971 the wrap and window size requests. The windowBits parameter is interpreted 972 the same as it is for inflateInit2. 973 974 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source 975 stream state was inconsistent (such as zalloc or state being Z_NULL), or if 976 the windowBits parameter is invalid. 977*/ 978 979ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, 980 int bits, 981 int value)); 982/* 983 This function inserts bits in the inflate input stream. The intent is 984 that this function is used to start inflating at a bit position in the 985 middle of a byte. The provided bits will be used before any bytes are used 986 from next_in. This function should only be used with raw inflate, and 987 should be used before the first inflate() call after inflateInit2() or 988 inflateReset(). bits must be less than or equal to 16, and that many of the 989 least significant bits of value will be inserted in the input. 990 991 If bits is negative, then the input stream bit buffer is emptied. Then 992 inflatePrime() can be called again to put bits in the buffer. This is used 993 to clear out bits leftover after feeding inflate a block description prior 994 to feeding inflate codes. 995 996 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source 997 stream state was inconsistent. 998*/ 999 1000ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); 1001/* 1002 This function returns two values, one in the lower 16 bits of the return 1003 value, and the other in the remaining upper bits, obtained by shifting the 1004 return value down 16 bits. If the upper value is -1 and the lower value is 1005 zero, then inflate() is currently decoding information outside of a block. 1006 If the upper value is -1 and the lower value is non-zero, then inflate is in 1007 the middle of a stored block, with the lower value equaling the number of 1008 bytes from the input remaining to copy. If the upper value is not -1, then 1009 it is the number of bits back from the current bit position in the input of 1010 the code (literal or length/distance pair) currently being processed. In 1011 that case the lower value is the number of bytes already emitted for that 1012 code. 1013 1014 A code is being processed if inflate is waiting for more input to complete 1015 decoding of the code, or if it has completed decoding but is waiting for 1016 more output space to write the literal or match data. 1017 1018 inflateMark() is used to mark locations in the input data for random 1019 access, which may be at bit positions, and to note those cases where the 1020 output of a code may span boundaries of random access blocks. The current 1021 location in the input stream can be determined from avail_in and data_type 1022 as noted in the description for the Z_BLOCK flush parameter for inflate. 1023 1024 inflateMark returns the value noted above or -1 << 16 if the provided 1025 source stream state was inconsistent. 1026*/ 1027 1028ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, 1029 gz_headerp head)); 1030/* 1031 inflateGetHeader() requests that gzip header information be stored in the 1032 provided gz_header structure. inflateGetHeader() may be called after 1033 inflateInit2() or inflateReset(), and before the first call of inflate(). 1034 As inflate() processes the gzip stream, head->done is zero until the header 1035 is completed, at which time head->done is set to one. If a zlib stream is 1036 being decoded, then head->done is set to -1 to indicate that there will be 1037 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be 1038 used to force inflate() to return immediately after header processing is 1039 complete and before any actual data is decompressed. 1040 1041 The text, time, xflags, and os fields are filled in with the gzip header 1042 contents. hcrc is set to true if there is a header CRC. (The header CRC 1043 was valid if done is set to one.) If extra is not Z_NULL, then extra_max 1044 contains the maximum number of bytes to write to extra. Once done is true, 1045 extra_len contains the actual extra field length, and extra contains the 1046 extra field, or that field truncated if extra_max is less than extra_len. 1047 If name is not Z_NULL, then up to name_max characters are written there, 1048 terminated with a zero unless the length is greater than name_max. If 1049 comment is not Z_NULL, then up to comm_max characters are written there, 1050 terminated with a zero unless the length is greater than comm_max. When any 1051 of extra, name, or comment are not Z_NULL and the respective field is not 1052 present in the header, then that field is set to Z_NULL to signal its 1053 absence. This allows the use of deflateSetHeader() with the returned 1054 structure to duplicate the header. However if those fields are set to 1055 allocated memory, then the application will need to save those pointers 1056 elsewhere so that they can be eventually freed. 1057 1058 If inflateGetHeader is not used, then the header information is simply 1059 discarded. The header is always checked for validity, including the header 1060 CRC if present. inflateReset() will reset the process to discard the header 1061 information. The application would need to call inflateGetHeader() again to 1062 retrieve the header from the next gzip stream. 1063 1064 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 1065 stream state was inconsistent. 1066*/ 1067 1068/* 1069ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, 1070 unsigned char FAR *window)); 1071 1072 Initialize the internal stream state for decompression using inflateBack() 1073 calls. The fields zalloc, zfree and opaque in strm must be initialized 1074 before the call. If zalloc and zfree are Z_NULL, then the default library- 1075 derived memory allocation routines are used. windowBits is the base two 1076 logarithm of the window size, in the range 8..15. window is a caller 1077 supplied buffer of that size. Except for special applications where it is 1078 assured that deflate was used with small window sizes, windowBits must be 15 1079 and a 32K byte window must be supplied to be able to decompress general 1080 deflate streams. 1081 1082 See inflateBack() for the usage of these routines. 1083 1084 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of 1085 the parameters are invalid, Z_MEM_ERROR if the internal state could not be 1086 allocated, or Z_VERSION_ERROR if the version of the library does not match 1087 the version of the header file. 1088*/ 1089 1090typedef unsigned (*in_func) OF((void FAR *, 1091 z_const unsigned char FAR * FAR *)); 1092typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); 1093 1094ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, 1095 in_func in, void FAR *in_desc, 1096 out_func out, void FAR *out_desc)); 1097/* 1098 inflateBack() does a raw inflate with a single call using a call-back 1099 interface for input and output. This is potentially more efficient than 1100 inflate() for file i/o applications, in that it avoids copying between the 1101 output and the sliding window by simply making the window itself the output 1102 buffer. inflate() can be faster on modern CPUs when used with large 1103 buffers. inflateBack() trusts the application to not change the output 1104 buffer passed by the output function, at least until inflateBack() returns. 1105 1106 inflateBackInit() must be called first to allocate the internal state 1107 and to initialize the state with the user-provided window buffer. 1108 inflateBack() may then be used multiple times to inflate a complete, raw 1109 deflate stream with each call. inflateBackEnd() is then called to free the 1110 allocated state. 1111 1112 A raw deflate stream is one with no zlib or gzip header or trailer. 1113 This routine would normally be used in a utility that reads zip or gzip 1114 files and writes out uncompressed files. The utility would decode the 1115 header and process the trailer on its own, hence this routine expects only 1116 the raw deflate stream to decompress. This is different from the normal 1117 behavior of inflate(), which expects either a zlib or gzip header and 1118 trailer around the deflate stream. 1119 1120 inflateBack() uses two subroutines supplied by the caller that are then 1121 called by inflateBack() for input and output. inflateBack() calls those 1122 routines until it reads a complete deflate stream and writes out all of the 1123 uncompressed data, or until it encounters an error. The function's 1124 parameters and return types are defined above in the in_func and out_func 1125 typedefs. inflateBack() will call in(in_desc, &buf) which should return the 1126 number of bytes of provided input, and a pointer to that input in buf. If 1127 there is no input available, in() must return zero--buf is ignored in that 1128 case--and inflateBack() will return a buffer error. inflateBack() will call 1129 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() 1130 should return zero on success, or non-zero on failure. If out() returns 1131 non-zero, inflateBack() will return with an error. Neither in() nor out() 1132 are permitted to change the contents of the window provided to 1133 inflateBackInit(), which is also the buffer that out() uses to write from. 1134 The length written by out() will be at most the window size. Any non-zero 1135 amount of input may be provided by in(). 1136 1137 For convenience, inflateBack() can be provided input on the first call by 1138 setting strm->next_in and strm->avail_in. If that input is exhausted, then 1139 in() will be called. Therefore strm->next_in must be initialized before 1140 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called 1141 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in 1142 must also be initialized, and then if strm->avail_in is not zero, input will 1143 initially be taken from strm->next_in[0 .. strm->avail_in - 1]. 1144 1145 The in_desc and out_desc parameters of inflateBack() is passed as the 1146 first parameter of in() and out() respectively when they are called. These 1147 descriptors can be optionally used to pass any information that the caller- 1148 supplied in() and out() functions need to do their job. 1149 1150 On return, inflateBack() will set strm->next_in and strm->avail_in to 1151 pass back any unused input that was provided by the last in() call. The 1152 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR 1153 if in() or out() returned an error, Z_DATA_ERROR if there was a format error 1154 in the deflate stream (in which case strm->msg is set to indicate the nature 1155 of the error), or Z_STREAM_ERROR if the stream was not properly initialized. 1156 In the case of Z_BUF_ERROR, an input or output error can be distinguished 1157 using strm->next_in which will be Z_NULL only if in() returned an error. If 1158 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning 1159 non-zero. (in() will always be called before out(), so strm->next_in is 1160 assured to be defined if out() returns non-zero.) Note that inflateBack() 1161 cannot return Z_OK. 1162*/ 1163 1164ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); 1165/* 1166 All memory allocated by inflateBackInit() is freed. 1167 1168 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream 1169 state was inconsistent. 1170*/ 1171 1172ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); 1173/* Return flags indicating compile-time options. 1174 1175 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: 1176 1.0: size of uInt 1177 3.2: size of uLong 1178 5.4: size of voidpf (pointer) 1179 7.6: size of z_off_t 1180 1181 Compiler, assembler, and debug options: 1182 8: DEBUG 1183 9: ASMV or ASMINF -- use ASM code 1184 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention 1185 11: 0 (reserved) 1186 1187 One-time table building (smaller code, but not thread-safe if true): 1188 12: BUILDFIXED -- build static block decoding tables when needed 1189 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed 1190 14,15: 0 (reserved) 1191 1192 Library content (indicates missing functionality): 1193 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking 1194 deflate code when not needed) 1195 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect 1196 and decode gzip streams (to avoid linking crc code) 1197 18-19: 0 (reserved) 1198 1199 Operation variations (changes in library functionality): 1200 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate 1201 21: FASTEST -- deflate algorithm with only one, lowest compression level 1202 22,23: 0 (reserved) 1203 1204 The sprintf variant used by gzprintf (zero is best): 1205 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format 1206 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! 1207 26: 0 = returns value, 1 = void -- 1 means inferred string length returned 1208 1209 Remainder: 1210 27-31: 0 (reserved) 1211 */ 1212 1213#ifndef Z_SOLO 1214 1215 /* utility functions */ 1216 1217/* 1218 The following utility functions are implemented on top of the basic 1219 stream-oriented functions. To simplify the interface, some default options 1220 are assumed (compression level and memory usage, standard memory allocation 1221 functions). The source code of these utility functions can be modified if 1222 you need special options. 1223*/ 1224 1225ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, 1226 const Bytef *source, uLong sourceLen)); 1227/* 1228 Compresses the source buffer into the destination buffer. sourceLen is 1229 the byte length of the source buffer. Upon entry, destLen is the total size 1230 of the destination buffer, which must be at least the value returned by 1231 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1232 compressed buffer. 1233 1234 compress returns Z_OK if success, Z_MEM_ERROR if there was not 1235 enough memory, Z_BUF_ERROR if there was not enough room in the output 1236 buffer. 1237*/ 1238 1239ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, 1240 const Bytef *source, uLong sourceLen, 1241 int level)); 1242/* 1243 Compresses the source buffer into the destination buffer. The level 1244 parameter has the same meaning as in deflateInit. sourceLen is the byte 1245 length of the source buffer. Upon entry, destLen is the total size of the 1246 destination buffer, which must be at least the value returned by 1247 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1248 compressed buffer. 1249 1250 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 1251 memory, Z_BUF_ERROR if there was not enough room in the output buffer, 1252 Z_STREAM_ERROR if the level parameter is invalid. 1253*/ 1254 1255ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); 1256/* 1257 compressBound() returns an upper bound on the compressed size after 1258 compress() or compress2() on sourceLen bytes. It would be used before a 1259 compress() or compress2() call to allocate the destination buffer. 1260*/ 1261 1262ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, 1263 const Bytef *source, uLong sourceLen)); 1264/* 1265 Decompresses the source buffer into the destination buffer. sourceLen is 1266 the byte length of the source buffer. Upon entry, destLen is the total size 1267 of the destination buffer, which must be large enough to hold the entire 1268 uncompressed data. (The size of the uncompressed data must have been saved 1269 previously by the compressor and transmitted to the decompressor by some 1270 mechanism outside the scope of this compression library.) Upon exit, destLen 1271 is the actual size of the uncompressed buffer. 1272 1273 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 1274 enough memory, Z_BUF_ERROR if there was not enough room in the output 1275 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In 1276 the case where there is not enough room, uncompress() will fill the output 1277 buffer with the uncompressed data up to that point. 1278*/ 1279 1280 /* gzip file access functions */ 1281 1282/* 1283 This library supports reading and writing files in gzip (.gz) format with 1284 an interface similar to that of stdio, using the functions that start with 1285 "gz". The gzip format is different from the zlib format. gzip is a gzip 1286 wrapper, documented in RFC 1952, wrapped around a deflate stream. 1287*/ 1288 1289typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ 1290 1291/* 1292ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); 1293 1294 Opens a gzip (.gz) file for reading or writing. The mode parameter is as 1295 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or 1296 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only 1297 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' 1298 for fixed code compression as in "wb9F". (See the description of 1299 deflateInit2 for more information about the strategy parameter.) 'T' will 1300 request transparent writing or appending with no compression and not using 1301 the gzip format. 1302 1303 "a" can be used instead of "w" to request that the gzip stream that will 1304 be written be appended to the file. "+" will result in an error, since 1305 reading and writing to the same gzip file is not supported. The addition of 1306 "x" when writing will create the file exclusively, which fails if the file 1307 already exists. On systems that support it, the addition of "e" when 1308 reading or writing will set the flag to close the file on an execve() call. 1309 1310 These functions, as well as gzip, will read and decode a sequence of gzip 1311 streams in a file. The append function of gzopen() can be used to create 1312 such a file. (Also see gzflush() for another way to do this.) When 1313 appending, gzopen does not test whether the file begins with a gzip stream, 1314 nor does it look for the end of the gzip streams to begin appending. gzopen 1315 will simply append a gzip stream to the existing file. 1316 1317 gzopen can be used to read a file which is not in gzip format; in this 1318 case gzread will directly read from the file without decompression. When 1319 reading, this will be detected automatically by looking for the magic two- 1320 byte gzip header. 1321 1322 gzopen returns NULL if the file could not be opened, if there was 1323 insufficient memory to allocate the gzFile state, or if an invalid mode was 1324 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). 1325 errno can be checked to determine if the reason gzopen failed was that the 1326 file could not be opened. 1327*/ 1328 1329ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); 1330/* 1331 gzdopen associates a gzFile with the file descriptor fd. File descriptors 1332 are obtained from calls like open, dup, creat, pipe or fileno (if the file 1333 has been previously opened with fopen). The mode parameter is as in gzopen. 1334 1335 The next call of gzclose on the returned gzFile will also close the file 1336 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor 1337 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, 1338 mode);. The duplicated descriptor should be saved to avoid a leak, since 1339 gzdopen does not close fd if it fails. If you are using fileno() to get the 1340 file descriptor from a FILE *, then you will have to use dup() to avoid 1341 double-close()ing the file descriptor. Both gzclose() and fclose() will 1342 close the associated file descriptor, so they need to have different file 1343 descriptors. 1344 1345 gzdopen returns NULL if there was insufficient memory to allocate the 1346 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not 1347 provided, or '+' was provided), or if fd is -1. The file descriptor is not 1348 used until the next gz* read, write, seek, or close operation, so gzdopen 1349 will not detect if fd is invalid (unless fd is -1). 1350*/ 1351 1352ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); 1353/* 1354 Set the internal buffer size used by this library's functions. The 1355 default buffer size is 8192 bytes. This function must be called after 1356 gzopen() or gzdopen(), and before any other calls that read or write the 1357 file. The buffer memory allocation is always deferred to the first read or 1358 write. Two buffers are allocated, either both of the specified size when 1359 writing, or one of the specified size and the other twice that size when 1360 reading. A larger buffer size of, for example, 64K or 128K bytes will 1361 noticeably increase the speed of decompression (reading). 1362 1363 The new buffer size also affects the maximum length for gzprintf(). 1364 1365 gzbuffer() returns 0 on success, or -1 on failure, such as being called 1366 too late. 1367*/ 1368 1369ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); 1370/* 1371 Dynamically update the compression level or strategy. See the description 1372 of deflateInit2 for the meaning of these parameters. 1373 1374 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not 1375 opened for writing. 1376*/ 1377 1378ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); 1379/* 1380 Reads the given number of uncompressed bytes from the compressed file. If 1381 the input file is not in gzip format, gzread copies the given number of 1382 bytes into the buffer directly from the file. 1383 1384 After reaching the end of a gzip stream in the input, gzread will continue 1385 to read, looking for another gzip stream. Any number of gzip streams may be 1386 concatenated in the input file, and will all be decompressed by gzread(). 1387 If something other than a gzip stream is encountered after a gzip stream, 1388 that remaining trailing garbage is ignored (and no error is returned). 1389 1390 gzread can be used to read a gzip file that is being concurrently written. 1391 Upon reaching the end of the input, gzread will return with the available 1392 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then 1393 gzclearerr can be used to clear the end of file indicator in order to permit 1394 gzread to be tried again. Z_OK indicates that a gzip stream was completed 1395 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the 1396 middle of a gzip stream. Note that gzread does not return -1 in the event 1397 of an incomplete gzip stream. This error is deferred until gzclose(), which 1398 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip 1399 stream. Alternatively, gzerror can be used before gzclose to detect this 1400 case. 1401 1402 gzread returns the number of uncompressed bytes actually read, less than 1403 len for end of file, or -1 for error. 1404*/ 1405 1406ZEXTERN int ZEXPORT gzwrite OF((gzFile file, 1407 voidpc buf, unsigned len)); 1408/* 1409 Writes the given number of uncompressed bytes into the compressed file. 1410 gzwrite returns the number of uncompressed bytes written or 0 in case of 1411 error. 1412*/ 1413 1414ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...)); 1415/* 1416 Converts, formats, and writes the arguments to the compressed file under 1417 control of the format string, as in fprintf. gzprintf returns the number of 1418 uncompressed bytes actually written, or 0 in case of error. The number of 1419 uncompressed bytes written is limited to 8191, or one less than the buffer 1420 size given to gzbuffer(). The caller should assure that this limit is not 1421 exceeded. If it is exceeded, then gzprintf() will return an error (0) with 1422 nothing written. In this case, there may also be a buffer overflow with 1423 unpredictable consequences, which is possible only if zlib was compiled with 1424 the insecure functions sprintf() or vsprintf() because the secure snprintf() 1425 or vsnprintf() functions were not available. This can be determined using 1426 zlibCompileFlags(). 1427*/ 1428 1429ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); 1430/* 1431 Writes the given null-terminated string to the compressed file, excluding 1432 the terminating null character. 1433 1434 gzputs returns the number of characters written, or -1 in case of error. 1435*/ 1436 1437ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); 1438/* 1439 Reads bytes from the compressed file until len-1 characters are read, or a 1440 newline character is read and transferred to buf, or an end-of-file 1441 condition is encountered. If any characters are read or if len == 1, the 1442 string is terminated with a null character. If no characters are read due 1443 to an end-of-file or len < 1, then the buffer is left untouched. 1444 1445 gzgets returns buf which is a null-terminated string, or it returns NULL 1446 for end-of-file or in case of error. If there was an error, the contents at 1447 buf are indeterminate. 1448*/ 1449 1450ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); 1451/* 1452 Writes c, converted to an unsigned char, into the compressed file. gzputc 1453 returns the value that was written, or -1 in case of error. 1454*/ 1455 1456ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); 1457/* 1458 Reads one byte from the compressed file. gzgetc returns this byte or -1 1459 in case of end of file or error. This is implemented as a macro for speed. 1460 As such, it does not do all of the checking the other functions do. I.e. 1461 it does not check to see if file is NULL, nor whether the structure file 1462 points to has been clobbered or not. 1463*/ 1464 1465ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); 1466/* 1467 Push one character back onto the stream to be read as the first character 1468 on the next read. At least one character of push-back is allowed. 1469 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will 1470 fail if c is -1, and may fail if a character has been pushed but not read 1471 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the 1472 output buffer size of pushed characters is allowed. (See gzbuffer above.) 1473 The pushed character will be discarded if the stream is repositioned with 1474 gzseek() or gzrewind(). 1475*/ 1476 1477ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); 1478/* 1479 Flushes all pending output into the compressed file. The parameter flush 1480 is as in the deflate() function. The return value is the zlib error number 1481 (see function gzerror below). gzflush is only permitted when writing. 1482 1483 If the flush parameter is Z_FINISH, the remaining data is written and the 1484 gzip stream is completed in the output. If gzwrite() is called again, a new 1485 gzip stream will be started in the output. gzread() is able to read such 1486 concatented gzip streams. 1487 1488 gzflush should be called only when strictly necessary because it will 1489 degrade compression if called too often. 1490*/ 1491 1492/* 1493ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, 1494 z_off_t offset, int whence)); 1495 1496 Sets the starting position for the next gzread or gzwrite on the given 1497 compressed file. The offset represents a number of bytes in the 1498 uncompressed data stream. The whence parameter is defined as in lseek(2); 1499 the value SEEK_END is not supported. 1500 1501 If the file is opened for reading, this function is emulated but can be 1502 extremely slow. If the file is opened for writing, only forward seeks are 1503 supported; gzseek then compresses a sequence of zeroes up to the new 1504 starting position. 1505 1506 gzseek returns the resulting offset location as measured in bytes from 1507 the beginning of the uncompressed stream, or -1 in case of error, in 1508 particular if the file is opened for writing and the new starting position 1509 would be before the current position. 1510*/ 1511 1512ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); 1513/* 1514 Rewinds the given file. This function is supported only for reading. 1515 1516 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) 1517*/ 1518 1519/* 1520ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); 1521 1522 Returns the starting position for the next gzread or gzwrite on the given 1523 compressed file. This position represents a number of bytes in the 1524 uncompressed data stream, and is zero when starting, even if appending or 1525 reading a gzip stream from the middle of a file using gzdopen(). 1526 1527 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) 1528*/ 1529 1530/* 1531ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); 1532 1533 Returns the current offset in the file being read or written. This offset 1534 includes the count of bytes that precede the gzip stream, for example when 1535 appending or when using gzdopen() for reading. When reading, the offset 1536 does not include as yet unused buffered input. This information can be used 1537 for a progress indicator. On error, gzoffset() returns -1. 1538*/ 1539 1540ZEXTERN int ZEXPORT gzeof OF((gzFile file)); 1541/* 1542 Returns true (1) if the end-of-file indicator has been set while reading, 1543 false (0) otherwise. Note that the end-of-file indicator is set only if the 1544 read tried to go past the end of the input, but came up short. Therefore, 1545 just like feof(), gzeof() may return false even if there is no more data to 1546 read, in the event that the last read request was for the exact number of 1547 bytes remaining in the input file. This will happen if the input file size 1548 is an exact multiple of the buffer size. 1549 1550 If gzeof() returns true, then the read functions will return no more data, 1551 unless the end-of-file indicator is reset by gzclearerr() and the input file 1552 has grown since the previous end of file was detected. 1553*/ 1554 1555ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); 1556/* 1557 Returns true (1) if file is being copied directly while reading, or false 1558 (0) if file is a gzip stream being decompressed. 1559 1560 If the input file is empty, gzdirect() will return true, since the input 1561 does not contain a gzip stream. 1562 1563 If gzdirect() is used immediately after gzopen() or gzdopen() it will 1564 cause buffers to be allocated to allow reading the file to determine if it 1565 is a gzip file. Therefore if gzbuffer() is used, it should be called before 1566 gzdirect(). 1567 1568 When writing, gzdirect() returns true (1) if transparent writing was 1569 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: 1570 gzdirect() is not needed when writing. Transparent writing must be 1571 explicitly requested, so the application already knows the answer. When 1572 linking statically, using gzdirect() will include all of the zlib code for 1573 gzip file reading and decompression, which may not be desired.) 1574*/ 1575 1576ZEXTERN int ZEXPORT gzclose OF((gzFile file)); 1577/* 1578 Flushes all pending output if necessary, closes the compressed file and 1579 deallocates the (de)compression state. Note that once file is closed, you 1580 cannot call gzerror with file, since its structures have been deallocated. 1581 gzclose must not be called more than once on the same file, just as free 1582 must not be called more than once on the same allocation. 1583 1584 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a 1585 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the 1586 last read ended in the middle of a gzip stream, or Z_OK on success. 1587*/ 1588 1589ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); 1590ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); 1591/* 1592 Same as gzclose(), but gzclose_r() is only for use when reading, and 1593 gzclose_w() is only for use when writing or appending. The advantage to 1594 using these instead of gzclose() is that they avoid linking in zlib 1595 compression or decompression code that is not used when only reading or only 1596 writing respectively. If gzclose() is used, then both compression and 1597 decompression code will be included the application when linking to a static 1598 zlib library. 1599*/ 1600 1601ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); 1602/* 1603 Returns the error message for the last error which occurred on the given 1604 compressed file. errnum is set to zlib error number. If an error occurred 1605 in the file system and not in the compression library, errnum is set to 1606 Z_ERRNO and the application may consult errno to get the exact error code. 1607 1608 The application must not modify the returned string. Future calls to 1609 this function may invalidate the previously returned string. If file is 1610 closed, then the string previously returned by gzerror will no longer be 1611 available. 1612 1613 gzerror() should be used to distinguish errors from end-of-file for those 1614 functions above that do not distinguish those cases in their return values. 1615*/ 1616 1617ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); 1618/* 1619 Clears the error and end-of-file flags for file. This is analogous to the 1620 clearerr() function in stdio. This is useful for continuing to read a gzip 1621 file that is being written concurrently. 1622*/ 1623 1624#endif /* !Z_SOLO */ 1625 1626 /* checksum functions */ 1627 1628/* 1629 These functions are not related to compression but are exported 1630 anyway because they might be useful in applications using the compression 1631 library. 1632*/ 1633 1634ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 1635/* 1636 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 1637 return the updated checksum. If buf is Z_NULL, this function returns the 1638 required initial value for the checksum. 1639 1640 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 1641 much faster. 1642 1643 Usage example: 1644 1645 uLong adler = adler32(0L, Z_NULL, 0); 1646 1647 while (read_buffer(buffer, length) != EOF) { 1648 adler = adler32(adler, buffer, length); 1649 } 1650 if (adler != original_adler) error(); 1651*/ 1652 1653/* 1654ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, 1655 z_off_t len2)); 1656 1657 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 1658 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for 1659 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of 1660 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note 1661 that the z_off_t type (like off_t) is a signed integer. If len2 is 1662 negative, the result has no meaning or utility. 1663*/ 1664 1665ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); 1666/* 1667 Update a running CRC-32 with the bytes buf[0..len-1] and return the 1668 updated CRC-32. If buf is Z_NULL, this function returns the required 1669 initial value for the crc. Pre- and post-conditioning (one's complement) is 1670 performed within this function so it shouldn't be done by the application. 1671 1672 Usage example: 1673 1674 uLong crc = crc32(0L, Z_NULL, 0); 1675 1676 while (read_buffer(buffer, length) != EOF) { 1677 crc = crc32(crc, buffer, length); 1678 } 1679 if (crc != original_crc) error(); 1680*/ 1681 1682/* 1683ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); 1684 1685 Combine two CRC-32 check values into one. For two sequences of bytes, 1686 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were 1687 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 1688 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and 1689 len2. 1690*/ 1691 1692 1693 /* various hacks, don't look :) */ 1694 1695/* deflateInit and inflateInit are macros to allow checking the zlib version 1696 * and the compiler's view of z_stream: 1697 */ 1698ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, 1699 const char *version, int stream_size)); 1700ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, 1701 const char *version, int stream_size)); 1702ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 1703 int windowBits, int memLevel, 1704 int strategy, const char *version, 1705 int stream_size)); 1706ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 1707 const char *version, int stream_size)); 1708ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, 1709 unsigned char FAR *window, 1710 const char *version, 1711 int stream_size)); 1712#define deflateInit(strm, level) \ 1713 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) 1714#define inflateInit(strm) \ 1715 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) 1716#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 1717 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ 1718 (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) 1719#define inflateInit2(strm, windowBits) \ 1720 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ 1721 (int)sizeof(z_stream)) 1722#define inflateBackInit(strm, windowBits, window) \ 1723 inflateBackInit_((strm), (windowBits), (window), \ 1724 ZLIB_VERSION, (int)sizeof(z_stream)) 1725 1726#ifndef Z_SOLO 1727 1728/* gzgetc() macro and its supporting function and exposed data structure. Note 1729 * that the real internal state is much larger than the exposed structure. 1730 * This abbreviated structure exposes just enough for the gzgetc() macro. The 1731 * user should not mess with these exposed elements, since their names or 1732 * behavior could change in the future, perhaps even capriciously. They can 1733 * only be used by the gzgetc() macro. You have been warned. 1734 */ 1735struct gzFile_s { 1736 unsigned have; 1737 unsigned char *next; 1738 z_off64_t pos; 1739}; 1740ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ 1741#ifdef Z_PREFIX_SET 1742# undef z_gzgetc 1743# define z_gzgetc(g) \ 1744 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) 1745#else 1746# define gzgetc(g) \ 1747 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) 1748#endif 1749 1750/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or 1751 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if 1752 * both are true, the application gets the *64 functions, and the regular 1753 * functions are changed to 64 bits) -- in case these are set on systems 1754 * without large file support, _LFS64_LARGEFILE must also be true 1755 */ 1756#ifdef Z_LARGE64 1757 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); 1758 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); 1759 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); 1760 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); 1761 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); 1762 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); 1763#endif 1764 1765#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) 1766# ifdef Z_PREFIX_SET 1767# define z_gzopen z_gzopen64 1768# define z_gzseek z_gzseek64 1769# define z_gztell z_gztell64 1770# define z_gzoffset z_gzoffset64 1771# define z_adler32_combine z_adler32_combine64 1772# define z_crc32_combine z_crc32_combine64 1773# else 1774# define gzopen gzopen64 1775# define gzseek gzseek64 1776# define gztell gztell64 1777# define gzoffset gzoffset64 1778# define adler32_combine adler32_combine64 1779# define crc32_combine crc32_combine64 1780# endif 1781# ifndef Z_LARGE64 1782 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); 1783 ZEXTERN off64_t ZEXPORT gzseek64 OF((gzFile, off64_t, int)); 1784 ZEXTERN off64_t ZEXPORT gztell64 OF((gzFile)); 1785 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); 1786 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, off64_t)); 1787 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, off64_t)); 1788# endif 1789#else 1790 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); 1791 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); 1792 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); 1793 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); 1794 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); 1795 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); 1796#endif 1797 1798#else /* Z_SOLO */ 1799 1800 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); 1801 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); 1802 1803#endif /* !Z_SOLO */ 1804 1805/* hack for buggy compilers */ 1806#if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) 1807 struct internal_state {int dummy;}; 1808#endif 1809 1810/* undocumented functions */ 1811ZEXTERN const char * ZEXPORT zError OF((int)); 1812ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); 1813ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void)); 1814ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); 1815ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp)); 1816ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp)); 1817#if defined(_WIN32) && !defined(Z_SOLO) 1818ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path, 1819 const char *mode)); 1820#endif 1821#if defined(STDC) || defined(Z_HAVE_STDARG_H) 1822# ifndef Z_SOLO 1823ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file, 1824 const char *format, 1825 va_list va)); 1826# endif 1827#endif 1828 1829#ifdef __cplusplus 1830} 1831#endif 1832 1833#endif /* ZLIB_H */ 1834