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