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