1 /* 2 * This file is derived from zlib.h and zconf.h from the zlib-1.2.3 3 * distribution by Jean-loup Gailly and Mark Adler, with some additions 4 * by Paul Mackerras to aid in implementing Deflate compression and 5 * decompression for PPP packets. 6 */ 7 8 /* 9 * ==FILEVERSION 960122== 10 * 11 * This marker is used by the Linux installation script to determine 12 * whether an up-to-date version of this file is already installed. 13 */ 14 15 /* zlib.h -- interface of the 'zlib' general purpose compression library 16 version 1.2.3, July 18th, 2005 17 18 Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler 19 20 This software is provided 'as-is', without any express or implied 21 warranty. In no event will the authors be held liable for any damages 22 arising from the use of this software. 23 24 Permission is granted to anyone to use this software for any purpose, 25 including commercial applications, and to alter it and redistribute it 26 freely, subject to the following restrictions: 27 28 1. The origin of this software must not be misrepresented; you must not 29 claim that you wrote the original software. If you use this software 30 in a product, an acknowledgment in the product documentation would be 31 appreciated but is not required. 32 2. Altered source versions must be plainly marked as such, and must not be 33 misrepresented as being the original software. 34 3. This notice may not be removed or altered from any source distribution. 35 36 Jean-loup Gailly Mark Adler 37 jloup@gzip.org madler@alumni.caltech.edu 38 39 40 The data format used by the zlib library is described by RFCs (Request for 41 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt 42 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). 43 */ 44 45 #ifndef ZLIB_H 46 #define ZLIB_H 47 48 #ifdef __cplusplus 49 extern "C" { 50 #endif 51 52 #define ZLIB_VERSION "1.2.3" 53 #define ZLIB_VERNUM 0x1230 54 55 /* #include "zconf.h" */ /* included directly here */ 56 /* zconf.h -- configuration of the zlib compression library 57 * Copyright (C) 1995-2005 Jean-loup Gailly. 58 * For conditions of distribution and use, see copyright notice in zlib.h 59 */ 60 61 /* Begin of new zconf.h */ 62 /* 63 * If you *really* need a unique prefix for all types and library functions, 64 * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it. 65 */ 66 #ifdef Z_PREFIX 67 # define deflateInit_ z_deflateInit_ 68 # define deflate z_deflate 69 # define deflateEnd z_deflateEnd 70 # define inflateInit_ z_inflateInit_ 71 # define inflate z_inflate 72 # define inflateEnd z_inflateEnd 73 # define deflateInit2_ z_deflateInit2_ 74 # define deflateSetDictionary z_deflateSetDictionary 75 # define deflateCopy z_deflateCopy 76 # define deflateReset z_deflateReset 77 # define deflateParams z_deflateParams 78 # define deflateBound z_deflateBound 79 # define deflatePrime z_deflatePrime 80 # define inflateInit2_ z_inflateInit2_ 81 # define inflateSetDictionary z_inflateSetDictionary 82 # define inflateSync z_inflateSync 83 # define inflateSyncPoint z_inflateSyncPoint 84 # define inflateCopy z_inflateCopy 85 # define inflateReset z_inflateReset 86 # define inflateBack z_inflateBack 87 # define inflateBackEnd z_inflateBackEnd 88 # define compress z_compress 89 # define compress2 z_compress2 90 # define compressBound z_compressBound 91 # define uncompress z_uncompress 92 # define adler32 z_adler32 93 # define crc32 z_crc32 94 # define get_crc_table z_get_crc_table 95 # define zError z_zError 96 97 # define alloc_func z_alloc_func 98 # define free_func z_free_func 99 # define in_func z_in_func 100 # define out_func z_out_func 101 # define Byte z_Byte 102 # define uInt z_uInt 103 # define uLong z_uLong 104 # define Bytef z_Bytef 105 # define charf z_charf 106 # define intf z_intf 107 # define uIntf z_uIntf 108 # define uLongf z_uLongf 109 # define voidpf z_voidpf 110 # define voidp z_voidp 111 #endif 112 113 #if defined(__MSDOS__) && !defined(MSDOS) 114 # define MSDOS 115 #endif 116 #if (defined(OS_2) || defined(__OS2__)) && !defined(OS2) 117 # define OS2 118 #endif 119 #if defined(_WINDOWS) && !defined(WINDOWS) 120 # define WINDOWS 121 #endif 122 #if defined(_WIN32) || defined(_WIN32_WCE) || defined(__WIN32__) 123 # ifndef WIN32 124 # define WIN32 125 # endif 126 #endif 127 #if (defined(MSDOS) || defined(OS2) || defined(WINDOWS)) && !defined(WIN32) 128 # if !defined(__GNUC__) && !defined(__FLAT__) && !defined(__386__) 129 # ifndef SYS16BIT 130 # define SYS16BIT 131 # endif 132 # endif 133 #endif 134 135 /* 136 * Compile with -DMAXSEG_64K if the alloc function cannot allocate more 137 * than 64k bytes at a time (needed on systems with 16-bit int). 138 */ 139 #ifdef SYS16BIT 140 # define MAXSEG_64K 141 #endif 142 #ifdef MSDOS 143 # define UNALIGNED_OK 144 #endif 145 146 #ifdef __STDC_VERSION__ 147 # ifndef STDC 148 # define STDC 149 # endif 150 # if __STDC_VERSION__ >= 199901L 151 # ifndef STDC99 152 # define STDC99 153 # endif 154 # endif 155 #endif 156 #if !defined(STDC) && (defined(__STDC__) || defined(__cplusplus)) 157 # define STDC 158 #endif 159 #if !defined(STDC) && (defined(__GNUC__) || defined(__BORLANDC__)) 160 # define STDC 161 #endif 162 #if !defined(STDC) && (defined(MSDOS) || defined(WINDOWS) || defined(WIN32)) 163 # define STDC 164 #endif 165 #if !defined(STDC) && (defined(OS2) || defined(__HOS_AIX__)) 166 # define STDC 167 #endif 168 169 #if defined(__OS400__) && !defined(STDC) /* iSeries (formerly AS/400). */ 170 # define STDC 171 #endif 172 173 #ifndef STDC 174 # ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */ 175 # define const /* note: need a more gentle solution here */ 176 # endif 177 #endif 178 179 /* Some Mac compilers merge all .h files incorrectly: */ 180 #if defined(__MWERKS__)||defined(applec)||defined(THINK_C)||defined(__SC__) 181 # define NO_DUMMY_DECL 182 #endif 183 184 /* Maximum value for memLevel in deflateInit2 */ 185 #ifndef MAX_MEM_LEVEL 186 # ifdef MAXSEG_64K 187 # define MAX_MEM_LEVEL 8 188 # else 189 # define MAX_MEM_LEVEL 9 190 # endif 191 #endif 192 193 /* Maximum value for windowBits in deflateInit2 and inflateInit2. 194 * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files 195 * created by gzip. (Files created by minigzip can still be extracted by 196 * gzip.) 197 */ 198 #ifndef MAX_WBITS 199 # define MAX_WBITS 15 /* 32K LZ77 window */ 200 #endif 201 202 /* The memory requirements for deflate are (in bytes): 203 (1 << (windowBits+2)) + (1 << (memLevel+9)) 204 that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values) 205 plus a few kilobytes for small objects. For example, if you want to reduce 206 the default memory requirements from 256K to 128K, compile with 207 make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7" 208 Of course this will generally degrade compression (there's no free lunch). 209 210 The memory requirements for inflate are (in bytes) 1 << windowBits 211 that is, 32K for windowBits=15 (default value) plus a few kilobytes 212 for small objects. 213 */ 214 215 /* Type declarations */ 216 217 #ifndef OF /* function prototypes */ 218 # ifdef STDC 219 # define OF(args) args 220 # else 221 # define OF(args) () 222 # endif 223 #endif 224 225 /* The following definitions for FAR are needed only for MSDOS mixed 226 * model programming (small or medium model with some far allocations). 227 * This was tested only with MSC; for other MSDOS compilers you may have 228 * to define NO_MEMCPY in zutil.h. If you don't need the mixed model, 229 * just define FAR to be empty. 230 */ 231 #ifdef SYS16BIT 232 # if defined(M_I86SM) || defined(M_I86MM) 233 /* MSC small or medium model */ 234 # define SMALL_MEDIUM 235 # ifdef _MSC_VER 236 # define FAR _far 237 # else 238 # define FAR far 239 # endif 240 # endif 241 # if (defined(__SMALL__) || defined(__MEDIUM__)) 242 /* Turbo C small or medium model */ 243 # define SMALL_MEDIUM 244 # ifdef __BORLANDC__ 245 # define FAR _far 246 # else 247 # define FAR far 248 # endif 249 # endif 250 #endif 251 252 #if defined(WINDOWS) || defined(WIN32) 253 /* If building or using zlib as a DLL, define ZLIB_DLL. 254 * This is not mandatory, but it offers a little performance increase. 255 */ 256 # ifdef ZLIB_DLL 257 # if defined(WIN32) && (!defined(__BORLANDC__) || (__BORLANDC__ >= 0x500)) 258 # ifdef ZLIB_INTERNAL 259 # define ZEXTERN extern __declspec(dllexport) 260 # else 261 # define ZEXTERN extern __declspec(dllimport) 262 # endif 263 # endif 264 # endif /* ZLIB_DLL */ 265 /* If building or using zlib with the WINAPI/WINAPIV calling convention, 266 * define ZLIB_WINAPI. 267 * Caution: the standard ZLIB1.DLL is NOT compiled using ZLIB_WINAPI. 268 */ 269 # ifdef ZLIB_WINAPI 270 # ifdef FAR 271 # undef FAR 272 # endif 273 # include <windows.h> 274 /* No need for _export, use ZLIB.DEF instead. */ 275 /* For complete Windows compatibility, use WINAPI, not __stdcall. */ 276 # define ZEXPORT WINAPI 277 # ifdef WIN32 278 # define ZEXPORTVA WINAPIV 279 # else 280 # define ZEXPORTVA FAR CDECL 281 # endif 282 # endif 283 #endif 284 285 #if defined (__BEOS__) 286 # ifdef ZLIB_DLL 287 # ifdef ZLIB_INTERNAL 288 # define ZEXPORT __declspec(dllexport) 289 # define ZEXPORTVA __declspec(dllexport) 290 # else 291 # define ZEXPORT __declspec(dllimport) 292 # define ZEXPORTVA __declspec(dllimport) 293 # endif 294 # endif 295 #endif 296 297 #ifndef ZEXTERN 298 # define ZEXTERN extern 299 #endif 300 #ifndef ZEXPORT 301 # define ZEXPORT 302 #endif 303 #ifndef ZEXPORTVA 304 # define ZEXPORTVA 305 #endif 306 307 #ifndef FAR 308 # define FAR 309 #endif 310 311 #if !defined(__MACTYPES__) 312 typedef unsigned char Byte; /* 8 bits */ 313 #endif 314 typedef unsigned int uInt; /* 16 bits or more */ 315 typedef unsigned long uLong; /* 32 bits or more */ 316 317 #ifdef SMALL_MEDIUM 318 /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */ 319 # define Bytef Byte FAR 320 #else 321 typedef Byte FAR Bytef; 322 #endif 323 typedef char FAR charf; 324 typedef int FAR intf; 325 typedef uInt FAR uIntf; 326 typedef uLong FAR uLongf; 327 328 #ifdef STDC 329 typedef void const *voidpc; 330 typedef void FAR *voidpf; 331 typedef void *voidp; 332 #else 333 typedef Byte const *voidpc; 334 typedef Byte FAR *voidpf; 335 typedef Byte *voidp; 336 #endif 337 338 # ifdef VMS 339 # include <unixio.h> /* for off_t */ 340 # endif 341 # define z_off_t off_t 342 #ifndef SEEK_SET 343 # define SEEK_SET 0 /* Seek from beginning of file. */ 344 # define SEEK_CUR 1 /* Seek from current position. */ 345 # define SEEK_END 2 /* Set file pointer to EOF plus "offset" */ 346 #endif 347 #ifndef z_off_t 348 # define z_off_t long 349 #endif 350 351 #if defined(__OS400__) 352 # define NO_vsnprintf 353 #endif 354 355 #if defined(__MVS__) 356 # define NO_vsnprintf 357 # ifdef FAR 358 # undef FAR 359 # endif 360 #endif 361 362 /* MVS linker does not support external names larger than 8 bytes */ 363 #if defined(__MVS__) 364 # pragma map(deflateInit_,"DEIN") 365 # pragma map(deflateInit2_,"DEIN2") 366 # pragma map(deflateEnd,"DEEND") 367 # pragma map(deflateBound,"DEBND") 368 # pragma map(inflateInit_,"ININ") 369 # pragma map(inflateInit2_,"ININ2") 370 # pragma map(inflateEnd,"INEND") 371 # pragma map(inflateSync,"INSY") 372 # pragma map(inflateSetDictionary,"INSEDI") 373 # pragma map(compressBound,"CMBND") 374 # pragma map(inflate_table,"INTABL") 375 # pragma map(inflate_fast,"INFA") 376 # pragma map(inflate_copyright,"INCOPY") 377 #endif 378 /* End of new zconf.h */ 379 380 /* 381 The 'zlib' compression library provides in-memory compression and 382 decompression functions, including integrity checks of the uncompressed 383 data. This version of the library supports only one compression method 384 (deflation) but other algorithms will be added later and will have the same 385 stream interface. 386 387 Compression can be done in a single step if the buffers are large 388 enough (for example if an input file is mmap'ed), or can be done by 389 repeated calls of the compression function. In the latter case, the 390 application must provide more input and/or consume the output 391 (providing more output space) before each call. 392 393 The compressed data format used by default by the in-memory functions is 394 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 395 around a deflate stream, which is itself documented in RFC 1951. 396 397 The library also supports reading and writing files in gzip (.gz) format 398 with an interface similar to that of stdio using the functions that start 399 with "gz". The gzip format is different from the zlib format. gzip is a 400 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. 401 402 This library can optionally read and write gzip streams in memory as well. 403 404 The zlib format was designed to be compact and fast for use in memory 405 and on communications channels. The gzip format was designed for single- 406 file compression on file systems, has a larger header than zlib to maintain 407 directory information, and uses a different, slower check method than zlib. 408 409 The library does not install any signal handler. The decoder checks 410 the consistency of the compressed data, so the library should never 411 crash even in case of corrupted input. 412 */ 413 414 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 415 typedef void (*free_func) OF((voidpf opaque, voidpf address, uInt size)); 416 typedef void (*cb_func) OF((Bytef *buf, uInt len)); 417 418 struct internal_state; 419 420 typedef struct z_stream_s { 421 Bytef *next_in; /* next input byte */ 422 uInt avail_in; /* number of bytes available at next_in */ 423 uLong total_in; /* total nb of input bytes read so far */ 424 Bytef *next_out; /* next output byte should be put there */ 425 uInt avail_out; /* remaining free space at next_out */ 426 uLong total_out; /* total nb of bytes output so far */ 427 char *msg; /* last error message, NULL if no error */ 428 struct internal_state FAR *state; /* not visible by applications */ 429 alloc_func zalloc; /* used to allocate the internal state */ 430 free_func zfree; /* used to free the internal state */ 431 voidpf opaque; /* private data object passed to zalloc and zfree */ 432 int data_type; /* best guess about the data type: 433 binary or text */ 434 cb_func outcb; /* called regularly just before blocks of output */ 435 uLong adler; /* adler32 value of the uncompressed data */ 436 uLong reserved; /* reserved for future use */ 437 } z_stream; 438 439 typedef z_stream FAR *z_streamp; 440 441 /* 442 gzip header information passed to and from zlib routines. See RFC 1952 443 for more details on the meanings of these fields. 444 */ 445 typedef struct gz_header_s { 446 int text; /* true if compressed data believed to be text */ 447 uLong time; /* modification time */ 448 int xflags; /* extra flags (not used when writing a gzip file) */ 449 int os; /* operating system */ 450 Bytef *extra; /* pointer to extra field or Z_NULL if none */ 451 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ 452 uInt extra_max; /* space at extra (only when reading header) */ 453 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ 454 uInt name_max; /* space at name (only when reading header) */ 455 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ 456 uInt comm_max; /* space at comment (only when reading header) */ 457 int hcrc; /* true if there was or will be a header crc */ 458 int done; /* true when done reading gzip header (not used 459 when writing a gzip file) */ 460 } gz_header; 461 462 typedef gz_header FAR *gz_headerp; 463 464 /* constants */ 465 #define Z_NO_FLUSH 0 466 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ 467 #define Z_SYNC_FLUSH 2 468 #define Z_FULL_FLUSH 3 469 #define Z_FINISH 4 470 #define Z_BLOCK 5 471 /* Allowed flush values; see deflate() and inflate() below for details */ 472 473 #define Z_OK 0 474 #define Z_STREAM_END 1 475 #define Z_NEED_DICT 2 476 #define Z_ERRNO (-1) 477 #define Z_STREAM_ERROR (-2) 478 #define Z_DATA_ERROR (-3) 479 #define Z_MEM_ERROR (-4) 480 #define Z_BUF_ERROR (-5) 481 #define Z_VERSION_ERROR (-6) 482 /* Return codes for the compression/decompression functions. Negative 483 * values are errors, positive values are used for special but normal events. 484 */ 485 486 #define Z_NO_COMPRESSION 0 487 #define Z_BEST_SPEED 1 488 #define Z_BEST_COMPRESSION 9 489 #define Z_DEFAULT_COMPRESSION (-1) 490 /* compression levels */ 491 492 #define Z_FILTERED 1 493 #define Z_HUFFMAN_ONLY 2 494 #define Z_RLE 3 495 #define Z_FIXED 4 496 #define Z_DEFAULT_STRATEGY 0 497 /* compression strategy; see deflateInit2() below for details */ 498 499 #define Z_BINARY 0 500 #define Z_TEXT 1 501 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ 502 #define Z_UNKNOWN 2 503 /* Possible values of the data_type field (though see inflate()) */ 504 505 #define Z_DEFLATED 8 506 /* The deflate compression method (the only one supported in this version) */ 507 508 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 509 510 /* basic functions */ 511 512 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. 513 If the first character differs, the library code actually used is 514 not compatible with the zlib.h header file used by the application. 515 This check is automatically made by deflateInit and inflateInit. 516 */ 517 518 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); 519 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, 520 const char *version, int stream_size)); 521 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); 522 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 523 int windowBits, int memLevel, 524 int strategy, const char *version, 525 int stream_size)); 526 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); 527 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, 528 const Bytef *dictionary, 529 uInt dictLength)); 530 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, 531 gz_headerp head)); 532 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, 533 int bits, 534 int value)); 535 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, 536 int level, 537 int strategy)); 538 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, 539 int good_length, 540 int max_lazy, 541 int nice_length, 542 int max_chain)); 543 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, 544 uLong sourceLen)); 545 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, 546 z_streamp source)); 547 548 549 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, 550 const char *version, int stream_size)); 551 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); 552 /* 553 inflate decompresses as much data as possible, and stops when the input 554 buffer becomes empty or the output buffer becomes full. It may introduce 555 some output latency (reading input without producing any output) except when 556 forced to flush. 557 558 The detailed semantics are as follows. inflate performs one or both of the 559 following actions: 560 561 - Decompress more input starting at next_in and update next_in and avail_in 562 accordingly. If not all input can be processed (because there is not 563 enough room in the output buffer), next_in is updated and processing 564 will resume at this point for the next call of inflate(). 565 566 - Provide more output starting at next_out and update next_out and avail_out 567 accordingly. inflate() provides as much output as possible, until there 568 is no more input data or no more space in the output buffer (see below 569 about the flush parameter). 570 571 Before the call of inflate(), the application should ensure that at least 572 one of the actions is possible, by providing more input and/or consuming 573 more output, and updating the next_* and avail_* values accordingly. 574 The application can consume the uncompressed output when it wants, for 575 example when the output buffer is full (avail_out == 0), or after each 576 call of inflate(). If inflate returns Z_OK and with zero avail_out, it 577 must be called again after making room in the output buffer because there 578 might be more output pending. 579 580 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, 581 Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much 582 output as possible to the output buffer. Z_BLOCK requests that inflate() stop 583 if and when it gets to the next deflate block boundary. When decoding the 584 zlib or gzip format, this will cause inflate() to return immediately after 585 the header and before the first block. When doing a raw inflate, inflate() 586 will go ahead and process the first block, and will return when it gets to 587 the end of that block, or when it runs out of data. 588 589 The Z_BLOCK option assists in appending to or combining deflate streams. 590 Also to assist in this, on return inflate() will set strm->data_type to the 591 number of unused bits in the last byte taken from strm->next_in, plus 64 592 if inflate() is currently decoding the last block in the deflate stream, 593 plus 128 if inflate() returned immediately after decoding an end-of-block 594 code or decoding the complete header up to just before the first byte of the 595 deflate stream. The end-of-block will not be indicated until all of the 596 uncompressed data from that block has been written to strm->next_out. The 597 number of unused bits may in general be greater than seven, except when 598 bit 7 of data_type is set, in which case the number of unused bits will be 599 less than eight. 600 601 inflate() should normally be called until it returns Z_STREAM_END or an 602 error. However if all decompression is to be performed in a single step 603 (a single call of inflate), the parameter flush should be set to 604 Z_FINISH. In this case all pending input is processed and all pending 605 output is flushed; avail_out must be large enough to hold all the 606 uncompressed data. (The size of the uncompressed data may have been saved 607 by the compressor for this purpose.) The next operation on this stream must 608 be inflateEnd to deallocate the decompression state. The use of Z_FINISH 609 is never required, but can be used to inform inflate that a faster approach 610 may be used for the single inflate() call. 611 612 In this implementation, inflate() always flushes as much output as 613 possible to the output buffer, and always uses the faster approach on the 614 first call. So the only effect of the flush parameter in this implementation 615 is on the return value of inflate(), as noted below, or when it returns early 616 because Z_BLOCK is used. 617 618 If a preset dictionary is needed after this call (see inflateSetDictionary 619 below), inflate sets strm->adler to the adler32 checksum of the dictionary 620 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 621 strm->adler to the adler32 checksum of all output produced so far (that is, 622 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 623 below. At the end of the stream, inflate() checks that its computed adler32 624 checksum is equal to that saved by the compressor and returns Z_STREAM_END 625 only if the checksum is correct. 626 627 inflate() will decompress and check either zlib-wrapped or gzip-wrapped 628 deflate data. The header type is detected automatically. Any information 629 contained in the gzip header is not retained, so applications that need that 630 information should instead use raw inflate, see inflateInit2() below, or 631 inflateBack() and perform their own processing of the gzip header and 632 trailer. 633 634 inflate() returns Z_OK if some progress has been made (more input processed 635 or more output produced), Z_STREAM_END if the end of the compressed data has 636 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 637 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 638 corrupted (input stream not conforming to the zlib format or incorrect check 639 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example 640 if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, 641 Z_BUF_ERROR if no progress is possible or if there was not enough room in the 642 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 643 inflate() can be called again with more input and more output space to 644 continue decompressing. If Z_DATA_ERROR is returned, the application may then 645 call inflateSync() to look for a good compression block if a partial recovery 646 of the data is desired. 647 */ 648 649 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); 650 /* 651 All dynamically allocated data structures for this stream are freed. 652 This function discards any unprocessed input and does not flush any 653 pending output. 654 655 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 656 was inconsistent. In the error case, msg may be set but then points to a 657 static string (which must not be deallocated). 658 */ 659 660 /* Advanced functions */ 661 662 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); 663 664 /* utility functions */ 665 666 /* 667 The following utility functions are implemented on top of the 668 basic stream-oriented functions. To simplify the interface, some 669 default options are assumed (compression level and memory usage, 670 standard memory allocation functions). The source code of these 671 utility functions can easily be modified if you need special options. 672 */ 673 674 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 675 /* 676 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 677 return the updated checksum. If buf is NULL, this function returns 678 the required initial value for the checksum. 679 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 680 much faster. Usage example: 681 682 uLong adler = adler32(0L, Z_NULL, 0); 683 684 while (read_buffer(buffer, length) != EOF) { 685 adler = adler32(adler, buffer, length); 686 } 687 if (adler != original_adler) error(); 688 */ 689 690 /* 691 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 692 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for 693 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of 694 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. 695 */ 696 697 ZEXTERN uInt ZEXPORT crc32 OF((uInt crc, const Bytef *buf, uInt len)); 698 /* 699 Update a running CRC-32 with the bytes buf[0..len-1] and return the 700 updated CRC-32. If buf is NULL, this function returns the required initial 701 value for the for the crc. Pre- and post-conditioning (one's complement) is 702 performed within this function so it shouldn't be done by the application. 703 Usage example: 704 705 uLong crc = crc32(0L, Z_NULL, 0); 706 707 while (read_buffer(buffer, length) != EOF) { 708 crc = crc32(crc, buffer, length); 709 } 710 if (crc != original_crc) error(); 711 */ 712 713 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 714 const char *version, int stream_size)); 715 #define inflateInit(strm) \ 716 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) 717 #define inflateInit2(strm, windowBits) \ 718 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) 719 720 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) 721 struct internal_state {int dummy;}; /* hack for buggy compilers */ 722 #endif 723 724 extern void *gzalloc(void *, unsigned, unsigned); 725 extern void gzfree(void *, void *, unsigned); 726 727 #ifdef __cplusplus 728 } 729 #endif 730 731 #endif /* ZLIB_H */ 732