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