1 /* zlib.h -- interface of the 'zlib' general purpose compression library 2 version 1.2.5, April 19th, 2010 3 4 Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler 5 6 This software is provided 'as-is', without any express or implied 7 warranty. In no event will the authors be held liable for any damages 8 arising from the use of this software. 9 10 Permission is granted to anyone to use this software for any purpose, 11 including commercial applications, and to alter it and redistribute it 12 freely, subject to the following restrictions: 13 14 1. The origin of this software must not be misrepresented; you must not 15 claim that you wrote the original software. If you use this software 16 in a product, an acknowledgment in the product documentation would be 17 appreciated but is not required. 18 2. Altered source versions must be plainly marked as such, and must not be 19 misrepresented as being the original software. 20 3. This notice may not be removed or altered from any source distribution. 21 22 Jean-loup Gailly Mark Adler 23 jloup@gzip.org madler@alumni.caltech.edu 24 25 26 The data format used by the zlib library is described by RFCs (Request for 27 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt 28 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). 29 */ 30 31 #ifndef ZLIB_H 32 #define ZLIB_H 33 34 #include "zconf.h" 35 36 #ifdef __cplusplus 37 extern "C" { 38 #endif 39 40 #define ZLIB_VERSION "1.2.5" 41 #define ZLIB_VERNUM 0x1250 42 #define ZLIB_VER_MAJOR 1 43 #define ZLIB_VER_MINOR 2 44 #define ZLIB_VER_REVISION 5 45 #define ZLIB_VER_SUBREVISION 0 46 47 /* 48 The 'zlib' compression library provides in-memory compression and 49 decompression functions, including integrity checks of the uncompressed data. 50 This version of the library supports only one compression method (deflation) 51 but other algorithms will be added later and will have the same stream 52 interface. 53 54 Compression can be done in a single step if the buffers are large enough, 55 or can be done by repeated calls of the compression function. In the latter 56 case, the application must provide more input and/or consume the output 57 (providing more output space) before each call. 58 59 The compressed data format used by default by the in-memory functions is 60 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 61 around a deflate stream, which is itself documented in RFC 1951. 62 63 The library also supports reading and writing files in gzip (.gz) format 64 with an interface similar to that of stdio using the functions that start 65 with "gz". The gzip format is different from the zlib format. gzip is a 66 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. 67 68 This library can optionally read and write gzip streams in memory as well. 69 70 The zlib format was designed to be compact and fast for use in memory 71 and on communications channels. The gzip format was designed for single- 72 file compression on file systems, has a larger header than zlib to maintain 73 directory information, and uses a different, slower check method than zlib. 74 75 The library does not install any signal handler. The decoder checks 76 the consistency of the compressed data, so the library should never crash 77 even in case of corrupted input. 78 */ 79 80 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 81 typedef void (*free_func) OF((voidpf opaque, voidpf address)); 82 83 struct internal_state; 84 85 typedef struct z_stream_s { 86 Bytef *next_in; /* next input byte */ 87 uInt avail_in; /* number of bytes available at next_in */ 88 uLong total_in; /* total nb of input bytes read so far */ 89 90 Bytef *next_out; /* next output byte should be put there */ 91 uInt avail_out; /* remaining free space at next_out */ 92 uLong total_out; /* total nb of bytes output so far */ 93 94 char *msg; /* last error message, NULL if no error */ 95 struct internal_state FAR *state; /* not visible by applications */ 96 97 alloc_func zalloc; /* used to allocate the internal state */ 98 free_func zfree; /* used to free the internal state */ 99 voidpf opaque; /* private data object passed to zalloc and zfree */ 100 101 int data_type; /* best guess about the data type: binary or text */ 102 uLong adler; /* adler32 value of the uncompressed data */ 103 uLong reserved; /* reserved for future use */ 104 } z_stream; 105 106 typedef z_stream FAR *z_streamp; 107 108 /* 109 gzip header information passed to and from zlib routines. See RFC 1952 110 for more details on the meanings of these fields. 111 */ 112 typedef struct gz_header_s { 113 int text; /* true if compressed data believed to be text */ 114 uLong time; /* modification time */ 115 int xflags; /* extra flags (not used when writing a gzip file) */ 116 int os; /* operating system */ 117 Bytef *extra; /* pointer to extra field or Z_NULL if none */ 118 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ 119 uInt extra_max; /* space at extra (only when reading header) */ 120 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ 121 uInt name_max; /* space at name (only when reading header) */ 122 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ 123 uInt comm_max; /* space at comment (only when reading header) */ 124 int hcrc; /* true if there was or will be a header crc */ 125 int done; /* true when done reading gzip header (not used 126 when writing a gzip file) */ 127 } gz_header; 128 129 typedef gz_header FAR *gz_headerp; 130 131 /* 132 The application must update next_in and avail_in when avail_in has dropped 133 to zero. It must update next_out and avail_out when avail_out has dropped 134 to zero. The application must initialize zalloc, zfree and opaque before 135 calling the init function. All other fields are set by the compression 136 library and must not be updated by the application. 137 138 The opaque value provided by the application will be passed as the first 139 parameter for calls of zalloc and zfree. This can be useful for custom 140 memory management. The compression library attaches no meaning to the 141 opaque value. 142 143 zalloc must return Z_NULL if there is not enough memory for the object. 144 If zlib is used in a multi-threaded application, zalloc and zfree must be 145 thread safe. 146 147 On 16-bit systems, the functions zalloc and zfree must be able to allocate 148 exactly 65536 bytes, but will not be required to allocate more than this if 149 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers 150 returned by zalloc for objects of exactly 65536 bytes *must* have their 151 offset normalized to zero. The default allocation function provided by this 152 library ensures this (see zutil.c). To reduce memory requirements and avoid 153 any allocation of 64K objects, at the expense of compression ratio, compile 154 the library with -DMAX_WBITS=14 (see zconf.h). 155 156 The fields total_in and total_out can be used for statistics or progress 157 reports. After compression, total_in holds the total size of the 158 uncompressed data and may be saved for use in the decompressor (particularly 159 if the decompressor wants to decompress everything in a single step). 160 */ 161 162 /* constants */ 163 164 #define Z_NO_FLUSH 0 165 #define Z_PARTIAL_FLUSH 1 166 #define Z_SYNC_FLUSH 2 167 #define Z_FULL_FLUSH 3 168 #define Z_FINISH 4 169 #define Z_BLOCK 5 170 #define Z_TREES 6 171 /* Allowed flush values; see deflate() and inflate() below for details */ 172 173 #define Z_OK 0 174 #define Z_STREAM_END 1 175 #define Z_NEED_DICT 2 176 #define Z_ERRNO (-1) 177 #define Z_STREAM_ERROR (-2) 178 #define Z_DATA_ERROR (-3) 179 #define Z_MEM_ERROR (-4) 180 #define Z_BUF_ERROR (-5) 181 #define Z_VERSION_ERROR (-6) 182 /* Return codes for the compression/decompression functions. Negative values 183 * are errors, positive values are used for special but normal events. 184 */ 185 186 #define Z_NO_COMPRESSION 0 187 #define Z_BEST_SPEED 1 188 #define Z_BEST_COMPRESSION 9 189 #define Z_DEFAULT_COMPRESSION (-1) 190 /* compression levels */ 191 192 #define Z_FILTERED 1 193 #define Z_HUFFMAN_ONLY 2 194 #define Z_RLE 3 195 #define Z_FIXED 4 196 #define Z_DEFAULT_STRATEGY 0 197 /* compression strategy; see deflateInit2() below for details */ 198 199 #define Z_BINARY 0 200 #define Z_TEXT 1 201 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ 202 #define Z_UNKNOWN 2 203 /* Possible values of the data_type field (though see inflate()) */ 204 205 #define Z_DEFLATED 8 206 /* The deflate compression method (the only one supported in this version) */ 207 208 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 209 210 #define zlib_version zlibVersion() 211 /* for compatibility with versions < 1.0.2 */ 212 213 214 /* basic functions */ 215 216 /* deflateInit commented out */ 217 218 /* 219 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); 220 221 Initializes the internal stream state for compression. The fields 222 zalloc, zfree and opaque must be initialized before by the caller. If 223 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default 224 allocation functions. 225 226 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 227 1 gives best speed, 9 gives best compression, 0 gives no compression at all 228 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION 229 requests a default compromise between speed and compression (currently 230 equivalent to level 6). 231 232 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 233 memory, Z_STREAM_ERROR if level is not a valid compression level, or 234 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 235 with the version assumed by the caller (ZLIB_VERSION). msg is set to null 236 if there is no error message. deflateInit does not perform any compression: 237 this will be done by deflate(). 238 */ 239 240 241 ZEXTERN const char * ZEXPORT zlibVersion OF((void)); 242 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. 243 If the first character differs, the library code actually used is not 244 compatible with the zlib.h header file used by the application. This check 245 is automatically made by deflateInit and inflateInit. 246 */ 247 248 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); 249 /* 250 deflate compresses as much data as possible, and stops when the input 251 buffer becomes empty or the output buffer becomes full. It may introduce 252 some output latency (reading input without producing any output) except when 253 forced to flush. 254 255 The detailed semantics are as follows. deflate performs one or both of the 256 following actions: 257 258 - Compress more input starting at next_in and update next_in and avail_in 259 accordingly. If not all input can be processed (because there is not 260 enough room in the output buffer), next_in and avail_in are updated and 261 processing will resume at this point for the next call of deflate(). 262 263 - Provide more output starting at next_out and update next_out and avail_out 264 accordingly. This action is forced if the parameter flush is non zero. 265 Forcing flush frequently degrades the compression ratio, so this parameter 266 should be set only when necessary (in interactive applications). Some 267 output may be provided even if flush is not set. 268 269 Before the call of deflate(), the application should ensure that at least 270 one of the actions is possible, by providing more input and/or consuming more 271 output, and updating avail_in or avail_out accordingly; avail_out should 272 never be zero before the call. The application can consume the compressed 273 output when it wants, for example when the output buffer is full (avail_out 274 == 0), or after each call of deflate(). If deflate returns Z_OK and with 275 zero avail_out, it must be called again after making room in the output 276 buffer because there might be more output pending. 277 278 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to 279 decide how much data to accumulate before producing output, in order to 280 maximize compression. 281 282 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 283 flushed to the output buffer and the output is aligned on a byte boundary, so 284 that the decompressor can get all input data available so far. (In 285 particular avail_in is zero after the call if enough output space has been 286 provided before the call.) Flushing may degrade compression for some 287 compression algorithms and so it should be used only when necessary. This 288 completes the current deflate block and follows it with an empty stored block 289 that is three bits plus filler bits to the next byte, followed by four bytes 290 (00 00 ff ff). 291 292 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the 293 output buffer, but the output is not aligned to a byte boundary. All of the 294 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. 295 This completes the current deflate block and follows it with an empty fixed 296 codes block that is 10 bits long. This assures that enough bytes are output 297 in order for the decompressor to finish the block before the empty fixed code 298 block. 299 300 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as 301 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to 302 seven bits of the current block are held to be written as the next byte after 303 the next deflate block is completed. In this case, the decompressor may not 304 be provided enough bits at this point in order to complete decompression of 305 the data provided so far to the compressor. It may need to wait for the next 306 block to be emitted. This is for advanced applications that need to control 307 the emission of deflate blocks. 308 309 If flush is set to Z_FULL_FLUSH, all output is flushed as with 310 Z_SYNC_FLUSH, and the compression state is reset so that decompression can 311 restart from this point if previous compressed data has been damaged or if 312 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 313 compression. 314 315 If deflate returns with avail_out == 0, this function must be called again 316 with the same value of the flush parameter and more output space (updated 317 avail_out), until the flush is complete (deflate returns with non-zero 318 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that 319 avail_out is greater than six to avoid repeated flush markers due to 320 avail_out == 0 on return. 321 322 If the parameter flush is set to Z_FINISH, pending input is processed, 323 pending output is flushed and deflate returns with Z_STREAM_END if there was 324 enough output space; if deflate returns with Z_OK, this function must be 325 called again with Z_FINISH and more output space (updated avail_out) but no 326 more input data, until it returns with Z_STREAM_END or an error. After 327 deflate has returned Z_STREAM_END, the only possible operations on the stream 328 are deflateReset or deflateEnd. 329 330 Z_FINISH can be used immediately after deflateInit if all the compression 331 is to be done in a single step. In this case, avail_out must be at least the 332 value returned by deflateBound (see below). If deflate does not return 333 Z_STREAM_END, then it must be called again as described above. 334 335 deflate() sets strm->adler to the adler32 checksum of all input read 336 so far (that is, total_in bytes). 337 338 deflate() may update strm->data_type if it can make a good guess about 339 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered 340 binary. This field is only for information purposes and does not affect the 341 compression algorithm in any manner. 342 343 deflate() returns Z_OK if some progress has been made (more input 344 processed or more output produced), Z_STREAM_END if all input has been 345 consumed and all output has been produced (only when flush is set to 346 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 347 if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible 348 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not 349 fatal, and deflate() can be called again with more input and more output 350 space to continue compressing. 351 */ 352 353 354 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); 355 /* 356 All dynamically allocated data structures for this stream are freed. 357 This function discards any unprocessed input and does not flush any pending 358 output. 359 360 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 361 stream state was inconsistent, Z_DATA_ERROR if the stream was freed 362 prematurely (some input or output was discarded). In the error case, msg 363 may be set but then points to a static string (which must not be 364 deallocated). 365 */ 366 367 368 /* inflateInit commented out */ 369 370 /* 371 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); 372 373 Initializes the internal stream state for decompression. The fields 374 next_in, avail_in, zalloc, zfree and opaque must be initialized before by 375 the caller. If next_in is not Z_NULL and avail_in is large enough (the 376 exact value depends on the compression method), inflateInit determines the 377 compression method from the zlib header and allocates all data structures 378 accordingly; otherwise the allocation will be deferred to the first call of 379 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to 380 use default allocation functions. 381 382 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 383 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 384 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 385 invalid, such as a null pointer to the structure. msg is set to null if 386 there is no error message. inflateInit does not perform any decompression 387 apart from possibly reading the zlib header if present: actual decompression 388 will be done by inflate(). (So next_in and avail_in may be modified, but 389 next_out and avail_out are unused and unchanged.) The current implementation 390 of inflateInit() does not process any header information -- that is deferred 391 until inflate() is called. 392 */ 393 394 395 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); 396 /* 397 inflate decompresses as much data as possible, and stops when the input 398 buffer becomes empty or the output buffer becomes full. It may introduce 399 some output latency (reading input without producing any output) except when 400 forced to flush. 401 402 The detailed semantics are as follows. inflate performs one or both of the 403 following actions: 404 405 - Decompress more input starting at next_in and update next_in and avail_in 406 accordingly. If not all input can be processed (because there is not 407 enough room in the output buffer), next_in is updated and processing will 408 resume at this point for the next call of inflate(). 409 410 - Provide more output starting at next_out and update next_out and avail_out 411 accordingly. inflate() provides as much output as possible, until there is 412 no more input data or no more space in the output buffer (see below about 413 the flush parameter). 414 415 Before the call of inflate(), the application should ensure that at least 416 one of the actions is possible, by providing more input and/or consuming more 417 output, and updating the next_* and avail_* values accordingly. The 418 application can consume the uncompressed output when it wants, for example 419 when the output buffer is full (avail_out == 0), or after each call of 420 inflate(). If inflate returns Z_OK and with zero avail_out, it must be 421 called again after making room in the output buffer because there might be 422 more output pending. 423 424 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, 425 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much 426 output as possible to the output buffer. Z_BLOCK requests that inflate() 427 stop if and when it gets to the next deflate block boundary. When decoding 428 the zlib or gzip format, this will cause inflate() to return immediately 429 after the header and before the first block. When doing a raw inflate, 430 inflate() will go ahead and process the first block, and will return when it 431 gets to the end of that block, or when it runs out of data. 432 433 The Z_BLOCK option assists in appending to or combining deflate streams. 434 Also to assist in this, on return inflate() will set strm->data_type to the 435 number of unused bits in the last byte taken from strm->next_in, plus 64 if 436 inflate() is currently decoding the last block in the deflate stream, plus 437 128 if inflate() returned immediately after decoding an end-of-block code or 438 decoding the complete header up to just before the first byte of the deflate 439 stream. The end-of-block will not be indicated until all of the uncompressed 440 data from that block has been written to strm->next_out. The number of 441 unused bits may in general be greater than seven, except when bit 7 of 442 data_type is set, in which case the number of unused bits will be less than 443 eight. data_type is set as noted here every time inflate() returns for all 444 flush options, and so can be used to determine the amount of currently 445 consumed input in bits. 446 447 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the 448 end of each deflate block header is reached, before any actual data in that 449 block is decoded. This allows the caller to determine the length of the 450 deflate block header for later use in random access within a deflate block. 451 256 is added to the value of strm->data_type when inflate() returns 452 immediately after reaching the end of the deflate block header. 453 454 inflate() should normally be called until it returns Z_STREAM_END or an 455 error. However if all decompression is to be performed in a single step (a 456 single call of inflate), the parameter flush should be set to Z_FINISH. In 457 this case all pending input is processed and all pending output is flushed; 458 avail_out must be large enough to hold all the uncompressed data. (The size 459 of the uncompressed data may have been saved by the compressor for this 460 purpose.) The next operation on this stream must be inflateEnd to deallocate 461 the decompression state. The use of Z_FINISH is never required, but can be 462 used to inform inflate that a faster approach may be used for the single 463 inflate() call. 464 465 In this implementation, inflate() always flushes as much output as 466 possible to the output buffer, and always uses the faster approach on the 467 first call. So the only effect of the flush parameter in this implementation 468 is on the return value of inflate(), as noted below, or when it returns early 469 because Z_BLOCK or Z_TREES is used. 470 471 If a preset dictionary is needed after this call (see inflateSetDictionary 472 below), inflate sets strm->adler to the adler32 checksum of the dictionary 473 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 474 strm->adler to the adler32 checksum of all output produced so far (that is, 475 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 476 below. At the end of the stream, inflate() checks that its computed adler32 477 checksum is equal to that saved by the compressor and returns Z_STREAM_END 478 only if the checksum is correct. 479 480 inflate() can decompress and check either zlib-wrapped or gzip-wrapped 481 deflate data. The header type is detected automatically, if requested when 482 initializing with inflateInit2(). Any information contained in the gzip 483 header is not retained, so applications that need that information should 484 instead use raw inflate, see inflateInit2() below, or inflateBack() and 485 perform their own processing of the gzip header and trailer. 486 487 inflate() returns Z_OK if some progress has been made (more input processed 488 or more output produced), Z_STREAM_END if the end of the compressed data has 489 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 490 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 491 corrupted (input stream not conforming to the zlib format or incorrect check 492 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example 493 next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory, 494 Z_BUF_ERROR if no progress is possible or if there was not enough room in the 495 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 496 inflate() can be called again with more input and more output space to 497 continue decompressing. If Z_DATA_ERROR is returned, the application may 498 then call inflateSync() to look for a good compression block if a partial 499 recovery of the data is desired. 500 */ 501 502 503 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); 504 /* 505 All dynamically allocated data structures for this stream are freed. 506 This function discards any unprocessed input and does not flush any pending 507 output. 508 509 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 510 was inconsistent. In the error case, msg may be set but then points to a 511 static string (which must not be deallocated). 512 */ 513 514 515 /* Advanced functions */ 516 517 /* 518 The following functions are needed only in some special applications. 519 */ 520 521 /* 522 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, 523 int level, 524 int method, 525 int windowBits, 526 int memLevel, 527 int strategy)); 528 529 This is another version of deflateInit with more compression options. The 530 fields next_in, zalloc, zfree and opaque must be initialized before by the 531 caller. 532 533 The method parameter is the compression method. It must be Z_DEFLATED in 534 this version of the library. 535 536 The windowBits parameter is the base two logarithm of the window size 537 (the size of the history buffer). It should be in the range 8..15 for this 538 version of the library. Larger values of this parameter result in better 539 compression at the expense of memory usage. The default value is 15 if 540 deflateInit is used instead. 541 542 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits 543 determines the window size. deflate() will then generate raw deflate data 544 with no zlib header or trailer, and will not compute an adler32 check value. 545 546 windowBits can also be greater than 15 for optional gzip encoding. Add 547 16 to windowBits to write a simple gzip header and trailer around the 548 compressed data instead of a zlib wrapper. The gzip header will have no 549 file name, no extra data, no comment, no modification time (set to zero), no 550 header crc, and the operating system will be set to 255 (unknown). If a 551 gzip stream is being written, strm->adler is a crc32 instead of an adler32. 552 553 The memLevel parameter specifies how much memory should be allocated 554 for the internal compression state. memLevel=1 uses minimum memory but is 555 slow and reduces compression ratio; memLevel=9 uses maximum memory for 556 optimal speed. The default value is 8. See zconf.h for total memory usage 557 as a function of windowBits and memLevel. 558 559 The strategy parameter is used to tune the compression algorithm. Use the 560 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 561 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no 562 string match), or Z_RLE to limit match distances to one (run-length 563 encoding). Filtered data consists mostly of small values with a somewhat 564 random distribution. In this case, the compression algorithm is tuned to 565 compress them better. The effect of Z_FILTERED is to force more Huffman 566 coding and less string matching; it is somewhat intermediate between 567 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as 568 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The 569 strategy parameter only affects the compression ratio but not the 570 correctness of the compressed output even if it is not set appropriately. 571 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler 572 decoder for special applications. 573 574 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 575 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid 576 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is 577 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is 578 set to null if there is no error message. deflateInit2 does not perform any 579 compression: this will be done by deflate(). 580 */ 581 582 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, 583 const Bytef *dictionary, 584 uInt dictLength)); 585 /* 586 Initializes the compression dictionary from the given byte sequence 587 without producing any compressed output. This function must be called 588 immediately after deflateInit, deflateInit2 or deflateReset, before any call 589 of deflate. The compressor and decompressor must use exactly the same 590 dictionary (see inflateSetDictionary). 591 592 The dictionary should consist of strings (byte sequences) that are likely 593 to be encountered later in the data to be compressed, with the most commonly 594 used strings preferably put towards the end of the dictionary. Using a 595 dictionary is most useful when the data to be compressed is short and can be 596 predicted with good accuracy; the data can then be compressed better than 597 with the default empty dictionary. 598 599 Depending on the size of the compression data structures selected by 600 deflateInit or deflateInit2, a part of the dictionary may in effect be 601 discarded, for example if the dictionary is larger than the window size 602 provided in deflateInit or deflateInit2. Thus the strings most likely to be 603 useful should be put at the end of the dictionary, not at the front. In 604 addition, the current implementation of deflate will use at most the window 605 size minus 262 bytes of the provided dictionary. 606 607 Upon return of this function, strm->adler is set to the adler32 value 608 of the dictionary; the decompressor may later use this value to determine 609 which dictionary has been used by the compressor. (The adler32 value 610 applies to the whole dictionary even if only a subset of the dictionary is 611 actually used by the compressor.) If a raw deflate was requested, then the 612 adler32 value is not computed and strm->adler is not set. 613 614 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 615 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is 616 inconsistent (for example if deflate has already been called for this stream 617 or if the compression method is bsort). deflateSetDictionary does not 618 perform any compression: this will be done by deflate(). 619 */ 620 621 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, 622 z_streamp source)); 623 /* 624 Sets the destination stream as a complete copy of the source stream. 625 626 This function can be useful when several compression strategies will be 627 tried, for example when there are several ways of pre-processing the input 628 data with a filter. The streams that will be discarded should then be freed 629 by calling deflateEnd. Note that deflateCopy duplicates the internal 630 compression state which can be quite large, so this strategy is slow and can 631 consume lots of memory. 632 633 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 634 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 635 (such as zalloc being Z_NULL). msg is left unchanged in both source and 636 destination. 637 */ 638 639 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); 640 /* 641 This function is equivalent to deflateEnd followed by deflateInit, 642 but does not free and reallocate all the internal compression state. The 643 stream will keep the same compression level and any other attributes that 644 may have been set by deflateInit2. 645 646 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 647 stream state was inconsistent (such as zalloc or state being Z_NULL). 648 */ 649 650 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, 651 int level, 652 int strategy)); 653 /* 654 Dynamically update the compression level and compression strategy. The 655 interpretation of level and strategy is as in deflateInit2. This can be 656 used to switch between compression and straight copy of the input data, or 657 to switch to a different kind of input data requiring a different strategy. 658 If the compression level is changed, the input available so far is 659 compressed with the old level (and may be flushed); the new level will take 660 effect only at the next call of deflate(). 661 662 Before the call of deflateParams, the stream state must be set as for 663 a call of deflate(), since the currently available input may have to be 664 compressed and flushed. In particular, strm->avail_out must be non-zero. 665 666 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source 667 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if 668 strm->avail_out was zero. 669 */ 670 671 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, 672 int good_length, 673 int max_lazy, 674 int nice_length, 675 int max_chain)); 676 /* 677 Fine tune deflate's internal compression parameters. This should only be 678 used by someone who understands the algorithm used by zlib's deflate for 679 searching for the best matching string, and even then only by the most 680 fanatic optimizer trying to squeeze out the last compressed bit for their 681 specific input data. Read the deflate.c source code for the meaning of the 682 max_lazy, good_length, nice_length, and max_chain parameters. 683 684 deflateTune() can be called after deflateInit() or deflateInit2(), and 685 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. 686 */ 687 688 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, 689 uLong sourceLen)); 690 /* 691 deflateBound() returns an upper bound on the compressed size after 692 deflation of sourceLen bytes. It must be called after deflateInit() or 693 deflateInit2(), and after deflateSetHeader(), if used. This would be used 694 to allocate an output buffer for deflation in a single pass, and so would be 695 called before deflate(). 696 */ 697 698 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, 699 int bits, 700 int value)); 701 /* 702 deflatePrime() inserts bits in the deflate output stream. The intent 703 is that this function is used to start off the deflate output with the bits 704 leftover from a previous deflate stream when appending to it. As such, this 705 function can only be used for raw deflate, and must be used before the first 706 deflate() call after a deflateInit2() or deflateReset(). bits must be less 707 than or equal to 16, and that many of the least significant bits of value 708 will be inserted in the output. 709 710 deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source 711 stream state was inconsistent. 712 */ 713 714 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, 715 gz_headerp head)); 716 /* 717 deflateSetHeader() provides gzip header information for when a gzip 718 stream is requested by deflateInit2(). deflateSetHeader() may be called 719 after deflateInit2() or deflateReset() and before the first call of 720 deflate(). The text, time, os, extra field, name, and comment information 721 in the provided gz_header structure are written to the gzip header (xflag is 722 ignored -- the extra flags are set according to the compression level). The 723 caller must assure that, if not Z_NULL, name and comment are terminated with 724 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are 725 available there. If hcrc is true, a gzip header crc is included. Note that 726 the current versions of the command-line version of gzip (up through version 727 1.3.x) do not support header crc's, and will report that it is a "multi-part 728 gzip file" and give up. 729 730 If deflateSetHeader is not used, the default gzip header has text false, 731 the time set to zero, and os set to 255, with no extra, name, or comment 732 fields. The gzip header is returned to the default state by deflateReset(). 733 734 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 735 stream state was inconsistent. 736 */ 737 738 /* 739 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, 740 int windowBits)); 741 742 This is another version of inflateInit with an extra parameter. The 743 fields next_in, avail_in, zalloc, zfree and opaque must be initialized 744 before by the caller. 745 746 The windowBits parameter is the base two logarithm of the maximum window 747 size (the size of the history buffer). It should be in the range 8..15 for 748 this version of the library. The default value is 15 if inflateInit is used 749 instead. windowBits must be greater than or equal to the windowBits value 750 provided to deflateInit2() while compressing, or it must be equal to 15 if 751 deflateInit2() was not used. If a compressed stream with a larger window 752 size is given as input, inflate() will return with the error code 753 Z_DATA_ERROR instead of trying to allocate a larger window. 754 755 windowBits can also be zero to request that inflate use the window size in 756 the zlib header of the compressed stream. 757 758 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits 759 determines the window size. inflate() will then process raw deflate data, 760 not looking for a zlib or gzip header, not generating a check value, and not 761 looking for any check values for comparison at the end of the stream. This 762 is for use with other formats that use the deflate compressed data format 763 such as zip. Those formats provide their own check values. If a custom 764 format is developed using the raw deflate format for compressed data, it is 765 recommended that a check value such as an adler32 or a crc32 be applied to 766 the uncompressed data as is done in the zlib, gzip, and zip formats. For 767 most applications, the zlib format should be used as is. Note that comments 768 above on the use in deflateInit2() applies to the magnitude of windowBits. 769 770 windowBits can also be greater than 15 for optional gzip decoding. Add 771 32 to windowBits to enable zlib and gzip decoding with automatic header 772 detection, or add 16 to decode only the gzip format (the zlib format will 773 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a 774 crc32 instead of an adler32. 775 776 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 777 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 778 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 779 invalid, such as a null pointer to the structure. msg is set to null if 780 there is no error message. inflateInit2 does not perform any decompression 781 apart from possibly reading the zlib header if present: actual decompression 782 will be done by inflate(). (So next_in and avail_in may be modified, but 783 next_out and avail_out are unused and unchanged.) The current implementation 784 of inflateInit2() does not process any header information -- that is 785 deferred until inflate() is called. 786 */ 787 788 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, 789 const Bytef *dictionary, 790 uInt dictLength)); 791 /* 792 Initializes the decompression dictionary from the given uncompressed byte 793 sequence. This function must be called immediately after a call of inflate, 794 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor 795 can be determined from the adler32 value returned by that call of inflate. 796 The compressor and decompressor must use exactly the same dictionary (see 797 deflateSetDictionary). For raw inflate, this function can be called 798 immediately after inflateInit2() or inflateReset() and before any call of 799 inflate() to set the dictionary. The application must insure that the 800 dictionary that was used for compression is provided. 801 802 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 803 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is 804 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 805 expected one (incorrect adler32 value). inflateSetDictionary does not 806 perform any decompression: this will be done by subsequent calls of 807 inflate(). 808 */ 809 810 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); 811 /* 812 Skips invalid compressed data until a full flush point (see above the 813 description of deflate with Z_FULL_FLUSH) can be found, or until all 814 available input is skipped. No output is provided. 815 816 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR 817 if no more input was provided, Z_DATA_ERROR if no flush point has been 818 found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the 819 success case, the application may save the current current value of total_in 820 which indicates where valid compressed data was found. In the error case, 821 the application may repeatedly call inflateSync, providing more input each 822 time, until success or end of the input data. 823 */ 824 825 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, 826 z_streamp source)); 827 /* 828 Sets the destination stream as a complete copy of the source stream. 829 830 This function can be useful when randomly accessing a large stream. The 831 first pass through the stream can periodically record the inflate state, 832 allowing restarting inflate at those points when randomly accessing the 833 stream. 834 835 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 836 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 837 (such as zalloc being Z_NULL). msg is left unchanged in both source and 838 destination. 839 */ 840 841 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); 842 /* 843 This function is equivalent to inflateEnd followed by inflateInit, 844 but does not free and reallocate all the internal decompression state. The 845 stream will keep attributes that may have been set by inflateInit2. 846 847 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 848 stream state was inconsistent (such as zalloc or state being Z_NULL). 849 */ 850 851 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, 852 int windowBits)); 853 /* 854 This function is the same as inflateReset, but it also permits changing 855 the wrap and window size requests. The windowBits parameter is interpreted 856 the same as it is for inflateInit2. 857 858 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source 859 stream state was inconsistent (such as zalloc or state being Z_NULL), or if 860 the windowBits parameter is invalid. 861 */ 862 863 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, 864 int bits, 865 int value)); 866 /* 867 This function inserts bits in the inflate input stream. The intent is 868 that this function is used to start inflating at a bit position in the 869 middle of a byte. The provided bits will be used before any bytes are used 870 from next_in. This function should only be used with raw inflate, and 871 should be used before the first inflate() call after inflateInit2() or 872 inflateReset(). bits must be less than or equal to 16, and that many of the 873 least significant bits of value will be inserted in the input. 874 875 If bits is negative, then the input stream bit buffer is emptied. Then 876 inflatePrime() can be called again to put bits in the buffer. This is used 877 to clear out bits leftover after feeding inflate a block description prior 878 to feeding inflate codes. 879 880 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source 881 stream state was inconsistent. 882 */ 883 884 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); 885 /* 886 This function returns two values, one in the lower 16 bits of the return 887 value, and the other in the remaining upper bits, obtained by shifting the 888 return value down 16 bits. If the upper value is -1 and the lower value is 889 zero, then inflate() is currently decoding information outside of a block. 890 If the upper value is -1 and the lower value is non-zero, then inflate is in 891 the middle of a stored block, with the lower value equaling the number of 892 bytes from the input remaining to copy. If the upper value is not -1, then 893 it is the number of bits back from the current bit position in the input of 894 the code (literal or length/distance pair) currently being processed. In 895 that case the lower value is the number of bytes already emitted for that 896 code. 897 898 A code is being processed if inflate is waiting for more input to complete 899 decoding of the code, or if it has completed decoding but is waiting for 900 more output space to write the literal or match data. 901 902 inflateMark() is used to mark locations in the input data for random 903 access, which may be at bit positions, and to note those cases where the 904 output of a code may span boundaries of random access blocks. The current 905 location in the input stream can be determined from avail_in and data_type 906 as noted in the description for the Z_BLOCK flush parameter for inflate. 907 908 inflateMark returns the value noted above or -1 << 16 if the provided 909 source stream state was inconsistent. 910 */ 911 912 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, 913 gz_headerp head)); 914 /* 915 inflateGetHeader() requests that gzip header information be stored in the 916 provided gz_header structure. inflateGetHeader() may be called after 917 inflateInit2() or inflateReset(), and before the first call of inflate(). 918 As inflate() processes the gzip stream, head->done is zero until the header 919 is completed, at which time head->done is set to one. If a zlib stream is 920 being decoded, then head->done is set to -1 to indicate that there will be 921 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be 922 used to force inflate() to return immediately after header processing is 923 complete and before any actual data is decompressed. 924 925 The text, time, xflags, and os fields are filled in with the gzip header 926 contents. hcrc is set to true if there is a header CRC. (The header CRC 927 was valid if done is set to one.) If extra is not Z_NULL, then extra_max 928 contains the maximum number of bytes to write to extra. Once done is true, 929 extra_len contains the actual extra field length, and extra contains the 930 extra field, or that field truncated if extra_max is less than extra_len. 931 If name is not Z_NULL, then up to name_max characters are written there, 932 terminated with a zero unless the length is greater than name_max. If 933 comment is not Z_NULL, then up to comm_max characters are written there, 934 terminated with a zero unless the length is greater than comm_max. When any 935 of extra, name, or comment are not Z_NULL and the respective field is not 936 present in the header, then that field is set to Z_NULL to signal its 937 absence. This allows the use of deflateSetHeader() with the returned 938 structure to duplicate the header. However if those fields are set to 939 allocated memory, then the application will need to save those pointers 940 elsewhere so that they can be eventually freed. 941 942 If inflateGetHeader is not used, then the header information is simply 943 discarded. The header is always checked for validity, including the header 944 CRC if present. inflateReset() will reset the process to discard the header 945 information. The application would need to call inflateGetHeader() again to 946 retrieve the header from the next gzip stream. 947 948 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 949 stream state was inconsistent. 950 */ 951 952 /* 953 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, 954 unsigned char FAR *window)); 955 956 Initialize the internal stream state for decompression using inflateBack() 957 calls. The fields zalloc, zfree and opaque in strm must be initialized 958 before the call. If zalloc and zfree are Z_NULL, then the default library- 959 derived memory allocation routines are used. windowBits is the base two 960 logarithm of the window size, in the range 8..15. window is a caller 961 supplied buffer of that size. Except for special applications where it is 962 assured that deflate was used with small window sizes, windowBits must be 15 963 and a 32K byte window must be supplied to be able to decompress general 964 deflate streams. 965 966 See inflateBack() for the usage of these routines. 967 968 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of 969 the paramaters are invalid, Z_MEM_ERROR if the internal state could not be 970 allocated, or Z_VERSION_ERROR if the version of the library does not match 971 the version of the header file. 972 */ 973 974 typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *)); 975 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); 976 977 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, 978 in_func in, void FAR *in_desc, 979 out_func out, void FAR *out_desc)); 980 /* 981 inflateBack() does a raw inflate with a single call using a call-back 982 interface for input and output. This is more efficient than inflate() for 983 file i/o applications in that it avoids copying between the output and the 984 sliding window by simply making the window itself the output buffer. This 985 function trusts the application to not change the output buffer passed by 986 the output function, at least until inflateBack() returns. 987 988 inflateBackInit() must be called first to allocate the internal state 989 and to initialize the state with the user-provided window buffer. 990 inflateBack() may then be used multiple times to inflate a complete, raw 991 deflate stream with each call. inflateBackEnd() is then called to free the 992 allocated state. 993 994 A raw deflate stream is one with no zlib or gzip header or trailer. 995 This routine would normally be used in a utility that reads zip or gzip 996 files and writes out uncompressed files. The utility would decode the 997 header and process the trailer on its own, hence this routine expects only 998 the raw deflate stream to decompress. This is different from the normal 999 behavior of inflate(), which expects either a zlib or gzip header and 1000 trailer around the deflate stream. 1001 1002 inflateBack() uses two subroutines supplied by the caller that are then 1003 called by inflateBack() for input and output. inflateBack() calls those 1004 routines until it reads a complete deflate stream and writes out all of the 1005 uncompressed data, or until it encounters an error. The function's 1006 parameters and return types are defined above in the in_func and out_func 1007 typedefs. inflateBack() will call in(in_desc, &buf) which should return the 1008 number of bytes of provided input, and a pointer to that input in buf. If 1009 there is no input available, in() must return zero--buf is ignored in that 1010 case--and inflateBack() will return a buffer error. inflateBack() will call 1011 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() 1012 should return zero on success, or non-zero on failure. If out() returns 1013 non-zero, inflateBack() will return with an error. Neither in() nor out() 1014 are permitted to change the contents of the window provided to 1015 inflateBackInit(), which is also the buffer that out() uses to write from. 1016 The length written by out() will be at most the window size. Any non-zero 1017 amount of input may be provided by in(). 1018 1019 For convenience, inflateBack() can be provided input on the first call by 1020 setting strm->next_in and strm->avail_in. If that input is exhausted, then 1021 in() will be called. Therefore strm->next_in must be initialized before 1022 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called 1023 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in 1024 must also be initialized, and then if strm->avail_in is not zero, input will 1025 initially be taken from strm->next_in[0 .. strm->avail_in - 1]. 1026 1027 The in_desc and out_desc parameters of inflateBack() is passed as the 1028 first parameter of in() and out() respectively when they are called. These 1029 descriptors can be optionally used to pass any information that the caller- 1030 supplied in() and out() functions need to do their job. 1031 1032 On return, inflateBack() will set strm->next_in and strm->avail_in to 1033 pass back any unused input that was provided by the last in() call. The 1034 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR 1035 if in() or out() returned an error, Z_DATA_ERROR if there was a format error 1036 in the deflate stream (in which case strm->msg is set to indicate the nature 1037 of the error), or Z_STREAM_ERROR if the stream was not properly initialized. 1038 In the case of Z_BUF_ERROR, an input or output error can be distinguished 1039 using strm->next_in which will be Z_NULL only if in() returned an error. If 1040 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning 1041 non-zero. (in() will always be called before out(), so strm->next_in is 1042 assured to be defined if out() returns non-zero.) Note that inflateBack() 1043 cannot return Z_OK. 1044 */ 1045 1046 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); 1047 /* 1048 All memory allocated by inflateBackInit() is freed. 1049 1050 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream 1051 state was inconsistent. 1052 */ 1053 1054 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); 1055 /* Return flags indicating compile-time options. 1056 1057 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: 1058 1.0: size of uInt 1059 3.2: size of uLong 1060 5.4: size of voidpf (pointer) 1061 7.6: size of z_off_t 1062 1063 Compiler, assembler, and debug options: 1064 8: DEBUG 1065 9: ASMV or ASMINF -- use ASM code 1066 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention 1067 11: 0 (reserved) 1068 1069 One-time table building (smaller code, but not thread-safe if true): 1070 12: BUILDFIXED -- build static block decoding tables when needed 1071 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed 1072 14,15: 0 (reserved) 1073 1074 Library content (indicates missing functionality): 1075 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking 1076 deflate code when not needed) 1077 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect 1078 and decode gzip streams (to avoid linking crc code) 1079 18-19: 0 (reserved) 1080 1081 Operation variations (changes in library functionality): 1082 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate 1083 21: FASTEST -- deflate algorithm with only one, lowest compression level 1084 22,23: 0 (reserved) 1085 1086 The sprintf variant used by gzprintf (zero is best): 1087 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format 1088 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! 1089 26: 0 = returns value, 1 = void -- 1 means inferred string length returned 1090 1091 Remainder: 1092 27-31: 0 (reserved) 1093 */ 1094 1095 1096 /* utility functions */ 1097 1098 /* 1099 The following utility functions are implemented on top of the basic 1100 stream-oriented functions. To simplify the interface, some default options 1101 are assumed (compression level and memory usage, standard memory allocation 1102 functions). The source code of these utility functions can be modified if 1103 you need special options. 1104 */ 1105 1106 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, 1107 const Bytef *source, uLong sourceLen)); 1108 /* 1109 Compresses the source buffer into the destination buffer. sourceLen is 1110 the byte length of the source buffer. Upon entry, destLen is the total size 1111 of the destination buffer, which must be at least the value returned by 1112 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1113 compressed buffer. 1114 1115 compress returns Z_OK if success, Z_MEM_ERROR if there was not 1116 enough memory, Z_BUF_ERROR if there was not enough room in the output 1117 buffer. 1118 */ 1119 1120 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, 1121 const Bytef *source, uLong sourceLen, 1122 int level)); 1123 /* 1124 Compresses the source buffer into the destination buffer. The level 1125 parameter has the same meaning as in deflateInit. sourceLen is the byte 1126 length of the source buffer. Upon entry, destLen is the total size of the 1127 destination buffer, which must be at least the value returned by 1128 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1129 compressed buffer. 1130 1131 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 1132 memory, Z_BUF_ERROR if there was not enough room in the output buffer, 1133 Z_STREAM_ERROR if the level parameter is invalid. 1134 */ 1135 1136 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); 1137 /* 1138 compressBound() returns an upper bound on the compressed size after 1139 compress() or compress2() on sourceLen bytes. It would be used before a 1140 compress() or compress2() call to allocate the destination buffer. 1141 */ 1142 1143 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, 1144 const Bytef *source, uLong sourceLen)); 1145 /* 1146 Decompresses the source buffer into the destination buffer. sourceLen is 1147 the byte length of the source buffer. Upon entry, destLen is the total size 1148 of the destination buffer, which must be large enough to hold the entire 1149 uncompressed data. (The size of the uncompressed data must have been saved 1150 previously by the compressor and transmitted to the decompressor by some 1151 mechanism outside the scope of this compression library.) Upon exit, destLen 1152 is the actual size of the uncompressed buffer. 1153 1154 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 1155 enough memory, Z_BUF_ERROR if there was not enough room in the output 1156 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. 1157 */ 1158 1159 1160 /* gzip file access functions */ 1161 1162 /* 1163 This library supports reading and writing files in gzip (.gz) format with 1164 an interface similar to that of stdio, using the functions that start with 1165 "gz". The gzip format is different from the zlib format. gzip is a gzip 1166 wrapper, documented in RFC 1952, wrapped around a deflate stream. 1167 */ 1168 1169 typedef voidp gzFile; /* opaque gzip file descriptor */ 1170 1171 /* 1172 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); 1173 1174 Opens a gzip (.gz) file for reading or writing. The mode parameter is as 1175 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or 1176 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only 1177 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' 1178 for fixed code compression as in "wb9F". (See the description of 1179 deflateInit2 for more information about the strategy parameter.) Also "a" 1180 can be used instead of "w" to request that the gzip stream that will be 1181 written be appended to the file. "+" will result in an error, since reading 1182 and writing to the same gzip file is not supported. 1183 1184 gzopen can be used to read a file which is not in gzip format; in this 1185 case gzread will directly read from the file without decompression. 1186 1187 gzopen returns NULL if the file could not be opened, if there was 1188 insufficient memory to allocate the gzFile state, or if an invalid mode was 1189 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). 1190 errno can be checked to determine if the reason gzopen failed was that the 1191 file could not be opened. 1192 */ 1193 1194 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); 1195 /* 1196 gzdopen associates a gzFile with the file descriptor fd. File descriptors 1197 are obtained from calls like open, dup, creat, pipe or fileno (if the file 1198 has been previously opened with fopen). The mode parameter is as in gzopen. 1199 1200 The next call of gzclose on the returned gzFile will also close the file 1201 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor 1202 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, 1203 mode);. The duplicated descriptor should be saved to avoid a leak, since 1204 gzdopen does not close fd if it fails. 1205 1206 gzdopen returns NULL if there was insufficient memory to allocate the 1207 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not 1208 provided, or '+' was provided), or if fd is -1. The file descriptor is not 1209 used until the next gz* read, write, seek, or close operation, so gzdopen 1210 will not detect if fd is invalid (unless fd is -1). 1211 */ 1212 1213 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); 1214 /* 1215 Set the internal buffer size used by this library's functions. The 1216 default buffer size is 8192 bytes. This function must be called after 1217 gzopen() or gzdopen(), and before any other calls that read or write the 1218 file. The buffer memory allocation is always deferred to the first read or 1219 write. Two buffers are allocated, either both of the specified size when 1220 writing, or one of the specified size and the other twice that size when 1221 reading. A larger buffer size of, for example, 64K or 128K bytes will 1222 noticeably increase the speed of decompression (reading). 1223 1224 The new buffer size also affects the maximum length for gzprintf(). 1225 1226 gzbuffer() returns 0 on success, or -1 on failure, such as being called 1227 too late. 1228 */ 1229 1230 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); 1231 /* 1232 Dynamically update the compression level or strategy. See the description 1233 of deflateInit2 for the meaning of these parameters. 1234 1235 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not 1236 opened for writing. 1237 */ 1238 1239 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); 1240 /* 1241 Reads the given number of uncompressed bytes from the compressed file. If 1242 the input file was not in gzip format, gzread copies the given number of 1243 bytes into the buffer. 1244 1245 After reaching the end of a gzip stream in the input, gzread will continue 1246 to read, looking for another gzip stream, or failing that, reading the rest 1247 of the input file directly without decompression. The entire input file 1248 will be read if gzread is called until it returns less than the requested 1249 len. 1250 1251 gzread returns the number of uncompressed bytes actually read, less than 1252 len for end of file, or -1 for error. 1253 */ 1254 1255 ZEXTERN int ZEXPORT gzwrite OF((gzFile file, 1256 voidpc buf, unsigned len)); 1257 /* 1258 Writes the given number of uncompressed bytes into the compressed file. 1259 gzwrite returns the number of uncompressed bytes written or 0 in case of 1260 error. 1261 */ 1262 1263 ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); 1264 /* 1265 Converts, formats, and writes the arguments to the compressed file under 1266 control of the format string, as in fprintf. gzprintf returns the number of 1267 uncompressed bytes actually written, or 0 in case of error. The number of 1268 uncompressed bytes written is limited to 8191, or one less than the buffer 1269 size given to gzbuffer(). The caller should assure that this limit is not 1270 exceeded. If it is exceeded, then gzprintf() will return an error (0) with 1271 nothing written. In this case, there may also be a buffer overflow with 1272 unpredictable consequences, which is possible only if zlib was compiled with 1273 the insecure functions sprintf() or vsprintf() because the secure snprintf() 1274 or vsnprintf() functions were not available. This can be determined using 1275 zlibCompileFlags(). 1276 */ 1277 1278 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); 1279 /* 1280 Writes the given null-terminated string to the compressed file, excluding 1281 the terminating null character. 1282 1283 gzputs returns the number of characters written, or -1 in case of error. 1284 */ 1285 1286 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); 1287 /* 1288 Reads bytes from the compressed file until len-1 characters are read, or a 1289 newline character is read and transferred to buf, or an end-of-file 1290 condition is encountered. If any characters are read or if len == 1, the 1291 string is terminated with a null character. If no characters are read due 1292 to an end-of-file or len < 1, then the buffer is left untouched. 1293 1294 gzgets returns buf which is a null-terminated string, or it returns NULL 1295 for end-of-file or in case of error. If there was an error, the contents at 1296 buf are indeterminate. 1297 */ 1298 1299 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); 1300 /* 1301 Writes c, converted to an unsigned char, into the compressed file. gzputc 1302 returns the value that was written, or -1 in case of error. 1303 */ 1304 1305 ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); 1306 /* 1307 Reads one byte from the compressed file. gzgetc returns this byte or -1 1308 in case of end of file or error. 1309 */ 1310 1311 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); 1312 /* 1313 Push one character back onto the stream to be read as the first character 1314 on the next read. At least one character of push-back is allowed. 1315 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will 1316 fail if c is -1, and may fail if a character has been pushed but not read 1317 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the 1318 output buffer size of pushed characters is allowed. (See gzbuffer above.) 1319 The pushed character will be discarded if the stream is repositioned with 1320 gzseek() or gzrewind(). 1321 */ 1322 1323 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); 1324 /* 1325 Flushes all pending output into the compressed file. The parameter flush 1326 is as in the deflate() function. The return value is the zlib error number 1327 (see function gzerror below). gzflush is only permitted when writing. 1328 1329 If the flush parameter is Z_FINISH, the remaining data is written and the 1330 gzip stream is completed in the output. If gzwrite() is called again, a new 1331 gzip stream will be started in the output. gzread() is able to read such 1332 concatented gzip streams. 1333 1334 gzflush should be called only when strictly necessary because it will 1335 degrade compression if called too often. 1336 */ 1337 1338 /* 1339 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, 1340 z_off_t offset, int whence)); 1341 1342 Sets the starting position for the next gzread or gzwrite on the given 1343 compressed file. The offset represents a number of bytes in the 1344 uncompressed data stream. The whence parameter is defined as in lseek(2); 1345 the value SEEK_END is not supported. 1346 1347 If the file is opened for reading, this function is emulated but can be 1348 extremely slow. If the file is opened for writing, only forward seeks are 1349 supported; gzseek then compresses a sequence of zeroes up to the new 1350 starting position. 1351 1352 gzseek returns the resulting offset location as measured in bytes from 1353 the beginning of the uncompressed stream, or -1 in case of error, in 1354 particular if the file is opened for writing and the new starting position 1355 would be before the current position. 1356 */ 1357 1358 ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); 1359 /* 1360 Rewinds the given file. This function is supported only for reading. 1361 1362 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) 1363 */ 1364 1365 /* 1366 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); 1367 1368 Returns the starting position for the next gzread or gzwrite on the given 1369 compressed file. This position represents a number of bytes in the 1370 uncompressed data stream, and is zero when starting, even if appending or 1371 reading a gzip stream from the middle of a file using gzdopen(). 1372 1373 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) 1374 */ 1375 1376 /* 1377 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); 1378 1379 Returns the current offset in the file being read or written. This offset 1380 includes the count of bytes that precede the gzip stream, for example when 1381 appending or when using gzdopen() for reading. When reading, the offset 1382 does not include as yet unused buffered input. This information can be used 1383 for a progress indicator. On error, gzoffset() returns -1. 1384 */ 1385 1386 ZEXTERN int ZEXPORT gzeof OF((gzFile file)); 1387 /* 1388 Returns true (1) if the end-of-file indicator has been set while reading, 1389 false (0) otherwise. Note that the end-of-file indicator is set only if the 1390 read tried to go past the end of the input, but came up short. Therefore, 1391 just like feof(), gzeof() may return false even if there is no more data to 1392 read, in the event that the last read request was for the exact number of 1393 bytes remaining in the input file. This will happen if the input file size 1394 is an exact multiple of the buffer size. 1395 1396 If gzeof() returns true, then the read functions will return no more data, 1397 unless the end-of-file indicator is reset by gzclearerr() and the input file 1398 has grown since the previous end of file was detected. 1399 */ 1400 1401 ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); 1402 /* 1403 Returns true (1) if file is being copied directly while reading, or false 1404 (0) if file is a gzip stream being decompressed. This state can change from 1405 false to true while reading the input file if the end of a gzip stream is 1406 reached, but is followed by data that is not another gzip stream. 1407 1408 If the input file is empty, gzdirect() will return true, since the input 1409 does not contain a gzip stream. 1410 1411 If gzdirect() is used immediately after gzopen() or gzdopen() it will 1412 cause buffers to be allocated to allow reading the file to determine if it 1413 is a gzip file. Therefore if gzbuffer() is used, it should be called before 1414 gzdirect(). 1415 */ 1416 1417 ZEXTERN int ZEXPORT gzclose OF((gzFile file)); 1418 /* 1419 Flushes all pending output if necessary, closes the compressed file and 1420 deallocates the (de)compression state. Note that once file is closed, you 1421 cannot call gzerror with file, since its structures have been deallocated. 1422 gzclose must not be called more than once on the same file, just as free 1423 must not be called more than once on the same allocation. 1424 1425 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a 1426 file operation error, or Z_OK on success. 1427 */ 1428 1429 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); 1430 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); 1431 /* 1432 Same as gzclose(), but gzclose_r() is only for use when reading, and 1433 gzclose_w() is only for use when writing or appending. The advantage to 1434 using these instead of gzclose() is that they avoid linking in zlib 1435 compression or decompression code that is not used when only reading or only 1436 writing respectively. If gzclose() is used, then both compression and 1437 decompression code will be included the application when linking to a static 1438 zlib library. 1439 */ 1440 1441 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); 1442 /* 1443 Returns the error message for the last error which occurred on the given 1444 compressed file. errnum is set to zlib error number. If an error occurred 1445 in the file system and not in the compression library, errnum is set to 1446 Z_ERRNO and the application may consult errno to get the exact error code. 1447 1448 The application must not modify the returned string. Future calls to 1449 this function may invalidate the previously returned string. If file is 1450 closed, then the string previously returned by gzerror will no longer be 1451 available. 1452 1453 gzerror() should be used to distinguish errors from end-of-file for those 1454 functions above that do not distinguish those cases in their return values. 1455 */ 1456 1457 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); 1458 /* 1459 Clears the error and end-of-file flags for file. This is analogous to the 1460 clearerr() function in stdio. This is useful for continuing to read a gzip 1461 file that is being written concurrently. 1462 */ 1463 1464 1465 /* checksum functions */ 1466 1467 /* 1468 These functions are not related to compression but are exported 1469 anyway because they might be useful in applications using the compression 1470 library. 1471 */ 1472 1473 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 1474 /* 1475 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 1476 return the updated checksum. If buf is Z_NULL, this function returns the 1477 required initial value for the checksum. 1478 1479 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 1480 much faster. 1481 1482 Usage example: 1483 1484 uLong adler = adler32(0L, Z_NULL, 0); 1485 1486 while (read_buffer(buffer, length) != EOF) { 1487 adler = adler32(adler, buffer, length); 1488 } 1489 if (adler != original_adler) error(); 1490 */ 1491 1492 /* 1493 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, 1494 z_off_t len2)); 1495 1496 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 1497 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for 1498 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of 1499 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. 1500 */ 1501 1502 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); 1503 /* 1504 Update a running CRC-32 with the bytes buf[0..len-1] and return the 1505 updated CRC-32. If buf is Z_NULL, this function returns the required 1506 initial value for the for the crc. Pre- and post-conditioning (one's 1507 complement) is performed within this function so it shouldn't be done by the 1508 application. 1509 1510 Usage example: 1511 1512 uLong crc = crc32(0L, Z_NULL, 0); 1513 1514 while (read_buffer(buffer, length) != EOF) { 1515 crc = crc32(crc, buffer, length); 1516 } 1517 if (crc != original_crc) error(); 1518 */ 1519 1520 /* 1521 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); 1522 1523 Combine two CRC-32 check values into one. For two sequences of bytes, 1524 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were 1525 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 1526 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and 1527 len2. 1528 */ 1529 1530 1531 /* various hacks, don't look :) */ 1532 1533 /* deflateInit and inflateInit are macros to allow checking the zlib version 1534 * and the compiler's view of z_stream: 1535 */ 1536 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, 1537 const char *version, int stream_size)); 1538 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, 1539 const char *version, int stream_size)); 1540 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 1541 int windowBits, int memLevel, 1542 int strategy, const char *version, 1543 int stream_size)); 1544 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 1545 const char *version, int stream_size)); 1546 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, 1547 unsigned char FAR *window, 1548 const char *version, 1549 int stream_size)); 1550 #define deflateInit(strm, level) \ 1551 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) 1552 #define inflateInit(strm) \ 1553 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) 1554 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 1555 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ 1556 (strategy), ZLIB_VERSION, sizeof(z_stream)) 1557 #define inflateInit2(strm, windowBits) \ 1558 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) 1559 #define inflateBackInit(strm, windowBits, window) \ 1560 inflateBackInit_((strm), (windowBits), (window), \ 1561 ZLIB_VERSION, sizeof(z_stream)) 1562 1563 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or 1564 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if 1565 * both are true, the application gets the *64 functions, and the regular 1566 * functions are changed to 64 bits) -- in case these are set on systems 1567 * without large file support, _LFS64_LARGEFILE must also be true 1568 */ 1569 /* 1570 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0 1571 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); 1572 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); 1573 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); 1574 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); 1575 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); 1576 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); 1577 #endif 1578 */ 1579 1580 #if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0 1581 1582 #if defined(gzopen) 1583 #undef gzopen 1584 #undef gzseek 1585 #undef gztell 1586 #undef gzoffset 1587 #undef adler32_combine 1588 #undef crc32_combine 1589 #endif 1590 1591 # define gzopen gzopen64 1592 # define gzseek gzseek64 1593 # define gztell gztell64 1594 # define gzoffset gzoffset64 1595 # define adler32_combine adler32_combine64 1596 # define crc32_combine crc32_combine64 1597 1598 # ifdef _LARGEFILE64_SOURCE 1599 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); 1600 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); 1601 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); 1602 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); 1603 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); 1604 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); 1605 # endif 1606 #else 1607 1608 #if defined(gzopen) 1609 #undef gzopen 1610 #undef gzseek 1611 #undef gztell 1612 #undef gzoffset 1613 #undef adler32_combine 1614 #undef crc32_combine 1615 #endif 1616 1617 1618 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0 1619 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); 1620 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); 1621 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); 1622 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); 1623 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); 1624 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); 1625 #else 1626 #ifndef WIN32 1627 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); 1628 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); 1629 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); 1630 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); 1631 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); 1632 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); 1633 #endif 1634 #endif 1635 #endif 1636 1637 /* hack for buggy compilers */ 1638 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) 1639 struct internal_state {int dummy;}; 1640 #endif 1641 1642 /* undocumented functions */ 1643 ZEXTERN const char * ZEXPORT zError OF((int)); 1644 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); 1645 ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void)); 1646 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); 1647 1648 #ifdef __cplusplus 1649 } 1650 #endif 1651 1652 #endif /* ZLIB_H */ 1653