1 /* $MirOS: src/kern/include/zlib.h,v 1.11 2013/10/31 20:06:13 tg Exp $ */ 2 3 /* zlib.h -- interface of the 'zlib' general purpose compression library 4 version 1.2.8, April 28th, 2013 5 6 Copyright (c) 2006-2013 Thorsten Glaser <tg@mirbsd.org> 7 Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler 8 9 This software is provided 'as-is', without any express or implied 10 warranty. In no event will the authors be held liable for any damages 11 arising from the use of this software. 12 13 Permission is granted to anyone to use this software for any purpose, 14 including commercial applications, and to alter it and redistribute it 15 freely, subject to the following restrictions: 16 17 1. The origin of this software must not be misrepresented; you must not 18 claim that you wrote the original software. If you use this software 19 in a product, an acknowledgment in the product documentation would be 20 appreciated but is not required. 21 2. Altered source versions must be plainly marked as such, and must not be 22 misrepresented as being the original software. 23 3. This notice may not be removed or altered from any source distribution. 24 25 Jean-loup Gailly Mark Adler 26 jloup@gzip.org madler@alumni.caltech.edu 27 28 29 The data format used by the zlib library is described by RFCs (Request for 30 Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950 31 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). 32 */ 33 34 #ifndef ZLIB_H 35 #define ZLIB_H 36 37 #include "zconf.h" 38 39 #ifdef __cplusplus 40 extern "C" { 41 #endif 42 43 #define ZLIB_VERSION "1.2.8.f-MirOS" 44 #define ZLIB_VERNUM 0x128f 45 #define ZLIB_VER_MAJOR 1 46 #define ZLIB_VER_MINOR 2 47 #define ZLIB_VER_REVISION 8 48 #define ZLIB_VER_SUBREVISION 0xf 49 50 /* 51 The 'zlib' compression library provides in-memory compression and 52 decompression functions, including integrity checks of the uncompressed data. 53 This version of the library supports only one compression method (deflation) 54 but other algorithms will be added later and will have the same stream 55 interface. 56 57 Compression can be done in a single step if the buffers are large enough, 58 or can be done by repeated calls of the compression function. In the latter 59 case, the application must provide more input and/or consume the output 60 (providing more output space) before each call. 61 62 The compressed data format used by default by the in-memory functions is 63 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 64 around a deflate stream, which is itself documented in RFC 1951. 65 66 The library also supports reading and writing files in gzip (.gz) format 67 with an interface similar to that of stdio using the functions that start 68 with "gz". The gzip format is different from the zlib format. gzip is a 69 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. 70 71 This library can optionally read and write gzip streams in memory as well. 72 73 The zlib format was designed to be compact and fast for use in memory 74 and on communications channels. The gzip format was designed for single- 75 file compression on file systems, has a larger header than zlib to maintain 76 directory information, and uses a different, slower check method than zlib. 77 78 The library does not install any signal handler. The decoder checks 79 the consistency of the compressed data, so the library should never crash 80 even in case of corrupted input. 81 */ 82 83 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 84 typedef void (*free_func) OF((voidpf opaque, voidpf address)); 85 86 struct internal_state; 87 88 typedef struct z_stream_s { 89 z_const Bytef *next_in; /* next input byte */ 90 uInt avail_in; /* number of bytes available at next_in */ 91 z_off_t total_in; /* total number of input bytes read so far */ 92 93 Bytef *next_out; /* next output byte should be put there */ 94 uInt avail_out; /* remaining free space at next_out */ 95 z_off_t total_out; /* total number of bytes output so far */ 96 97 z_const char *msg; /* last error message, NULL if no error */ 98 struct internal_state FAR *state; /* not visible by applications */ 99 100 alloc_func zalloc; /* used to allocate the internal state */ 101 free_func zfree; /* used to free the internal state */ 102 voidpf opaque; /* private data object passed to zalloc and zfree */ 103 104 int data_type; /* best guess about the data type: binary or text */ 105 uLong adler; /* adler32 value of the uncompressed data */ 106 uLong reserved; /* reserved for future use */ 107 } z_stream; 108 109 typedef z_stream FAR *z_streamp; 110 111 /* 112 gzip header information passed to and from zlib routines. See RFC 1952 113 for more details on the meanings of these fields. 114 */ 115 typedef struct gz_header_s { 116 int text; /* true if compressed data believed to be text */ 117 uLong time; /* modification time */ 118 int xflags; /* extra flags (not used when writing a gzip file) */ 119 int os; /* operating system */ 120 Bytef *extra; /* pointer to extra field or Z_NULL if none */ 121 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ 122 uInt extra_max; /* space at extra (only when reading header) */ 123 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ 124 uInt name_max; /* space at name (only when reading header) */ 125 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ 126 uInt comm_max; /* space at comment (only when reading header) */ 127 int hcrc; /* true if there was or will be a header crc */ 128 int done; /* true when done reading gzip header (not used 129 when writing a gzip file) */ 130 } gz_header; 131 132 typedef gz_header FAR *gz_headerp; 133 134 /* 135 The application must update next_in and avail_in when avail_in has dropped 136 to zero. It must update next_out and avail_out when avail_out has dropped 137 to zero. The application must initialize zalloc, zfree and opaque before 138 calling the init function. All other fields are set by the compression 139 library and must not be updated by the application. 140 141 The opaque value provided by the application will be passed as the first 142 parameter for calls of zalloc and zfree. This can be useful for custom 143 memory management. The compression library attaches no meaning to the 144 opaque value. 145 146 zalloc must return Z_NULL if there is not enough memory for the object. 147 If zlib is used in a multi-threaded application, zalloc and zfree must be 148 thread safe. 149 150 On 16-bit systems, the functions zalloc and zfree must be able to allocate 151 exactly 65536 bytes, but will not be required to allocate more than this if 152 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers 153 returned by zalloc for objects of exactly 65536 bytes *must* have their 154 offset normalized to zero. The default allocation function provided by this 155 library ensures this (see zutil.c). To reduce memory requirements and avoid 156 any allocation of 64K objects, at the expense of compression ratio, compile 157 the library with -DMAX_WBITS=14 (see zconf.h). 158 159 The fields total_in and total_out can be used for statistics or progress 160 reports. After compression, total_in holds the total size of the 161 uncompressed data and may be saved for use in the decompressor (particularly 162 if the decompressor wants to decompress everything in a single step). 163 */ 164 165 /* constants */ 166 167 #define Z_NO_FLUSH 0 168 #define Z_PARTIAL_FLUSH 1 169 #define Z_SYNC_FLUSH 2 170 #define Z_FULL_FLUSH 3 171 #define Z_FINISH 4 172 #define Z_BLOCK 5 173 #define Z_TREES 6 174 /* Allowed flush values; see deflate() and inflate() below for details */ 175 176 #define Z_OK 0 177 #define Z_STREAM_END 1 178 #define Z_NEED_DICT 2 179 #define Z_ERRNO (-1) 180 #define Z_STREAM_ERROR (-2) 181 #define Z_DATA_ERROR (-3) 182 #define Z_MEM_ERROR (-4) 183 #define Z_BUF_ERROR (-5) 184 #define Z_VERSION_ERROR (-6) 185 /* Return codes for the compression/decompression functions. Negative values 186 * are errors, positive values are used for special but normal events. 187 */ 188 189 #define Z_NO_COMPRESSION 0 190 #define Z_BEST_SPEED 1 191 #define Z_BEST_COMPRESSION 9 192 #define Z_DEFAULT_COMPRESSION (-1) 193 /* compression levels */ 194 195 #define Z_FILTERED 1 196 #define Z_HUFFMAN_ONLY 2 197 #define Z_RLE 3 198 #define Z_FIXED 4 199 #define Z_DEFAULT_STRATEGY 0 200 /* compression strategy; see deflateInit2() below for details */ 201 202 #define Z_BINARY 0 203 #define Z_TEXT 1 204 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ 205 #define Z_UNKNOWN 2 206 /* Possible values of the data_type field (though see inflate()) */ 207 208 #define Z_DEFLATED 8 209 /* The deflate compression method (the only one supported in this version) */ 210 211 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 212 213 #define zlib_version zlibVersion() 214 /* for compatibility with versions < 1.0.2 */ 215 216 217 /* basic functions */ 218 219 ZEXTERN const char * ZEXPORT zlibVersion OF((void)); 220 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. 221 If the first character differs, the library code actually used is not 222 compatible with the zlib.h header file used by the application. This check 223 is automatically made by deflateInit and inflateInit. 224 */ 225 226 /* 227 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); 228 229 Initializes the internal stream state for compression. The fields 230 zalloc, zfree and opaque must be initialized before by the caller. If 231 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default 232 allocation functions. 233 234 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 235 1 gives best speed, 9 gives best compression, 0 gives no compression at all 236 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION 237 requests a default compromise between speed and compression (currently 238 equivalent to level 6). 239 240 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 241 memory, Z_STREAM_ERROR if level is not a valid compression level, or 242 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 243 with the version assumed by the caller (ZLIB_VERSION). msg is set to null 244 if there is no error message. deflateInit does not perform any compression: 245 this will be done by deflate(). 246 */ 247 248 249 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); 250 /* 251 deflate compresses as much data as possible, and stops when the input 252 buffer becomes empty or the output buffer becomes full. It may introduce 253 some output latency (reading input without producing any output) except when 254 forced to flush. 255 256 The detailed semantics are as follows. deflate performs one or both of the 257 following actions: 258 259 - Compress more input starting at next_in and update next_in and avail_in 260 accordingly. If not all input can be processed (because there is not 261 enough room in the output buffer), next_in and avail_in are updated and 262 processing will resume at this point for the next call of deflate(). 263 264 - Provide more output starting at next_out and update next_out and avail_out 265 accordingly. This action is forced if the parameter flush is non zero. 266 Forcing flush frequently degrades the compression ratio, so this parameter 267 should be set only when necessary (in interactive applications). Some 268 output may be provided even if flush is not set. 269 270 Before the call of deflate(), the application should ensure that at least 271 one of the actions is possible, by providing more input and/or consuming more 272 output, and updating avail_in or avail_out accordingly; avail_out should 273 never be zero before the call. The application can consume the compressed 274 output when it wants, for example when the output buffer is full (avail_out 275 == 0), or after each call of deflate(). If deflate returns Z_OK and with 276 zero avail_out, it must be called again after making room in the output 277 buffer because there might be more output pending. 278 279 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to 280 decide how much data to accumulate before producing output, in order to 281 maximize compression. 282 283 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 284 flushed to the output buffer and the output is aligned on a byte boundary, so 285 that the decompressor can get all input data available so far. (In 286 particular avail_in is zero after the call if enough output space has been 287 provided before the call.) Flushing may degrade compression for some 288 compression algorithms and so it should be used only when necessary. This 289 completes the current deflate block and follows it with an empty stored block 290 that is three bits plus filler bits to the next byte, followed by four bytes 291 (00 00 ff ff). 292 293 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the 294 output buffer, but the output is not aligned to a byte boundary. All of the 295 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. 296 This completes the current deflate block and follows it with an empty fixed 297 codes block that is 10 bits long. This assures that enough bytes are output 298 in order for the decompressor to finish the block before the empty fixed code 299 block. 300 301 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as 302 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to 303 seven bits of the current block are held to be written as the next byte after 304 the next deflate block is completed. In this case, the decompressor may not 305 be provided enough bits at this point in order to complete decompression of 306 the data provided so far to the compressor. It may need to wait for the next 307 block to be emitted. This is for advanced applications that need to control 308 the emission of deflate blocks. 309 310 If flush is set to Z_FULL_FLUSH, all output is flushed as with 311 Z_SYNC_FLUSH, and the compression state is reset so that decompression can 312 restart from this point if previous compressed data has been damaged or if 313 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 314 compression. 315 316 If deflate returns with avail_out == 0, this function must be called again 317 with the same value of the flush parameter and more output space (updated 318 avail_out), until the flush is complete (deflate returns with non-zero 319 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that 320 avail_out is greater than six to avoid repeated flush markers due to 321 avail_out == 0 on return. 322 323 If the parameter flush is set to Z_FINISH, pending input is processed, 324 pending output is flushed and deflate returns with Z_STREAM_END if there was 325 enough output space; if deflate returns with Z_OK, this function must be 326 called again with Z_FINISH and more output space (updated avail_out) but no 327 more input data, until it returns with Z_STREAM_END or an error. After 328 deflate has returned Z_STREAM_END, the only possible operations on the stream 329 are deflateReset or deflateEnd. 330 331 Z_FINISH can be used immediately after deflateInit if all the compression 332 is to be done in a single step. In this case, avail_out must be at least the 333 value returned by deflateBound (see below). Then deflate is guaranteed to 334 return Z_STREAM_END. If not enough output space is provided, deflate will 335 not return Z_STREAM_END, and it must be called again as described above. 336 337 deflate() sets strm->adler to the adler32 checksum of all input read 338 so far (that is, total_in bytes). 339 340 deflate() may update strm->data_type if it can make a good guess about 341 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered 342 binary. This field is only for information purposes and does not affect the 343 compression algorithm in any manner. 344 345 deflate() returns Z_OK if some progress has been made (more input 346 processed or more output produced), Z_STREAM_END if all input has been 347 consumed and all output has been produced (only when flush is set to 348 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 349 if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible 350 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not 351 fatal, and deflate() can be called again with more input and more output 352 space to continue compressing. 353 */ 354 355 356 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); 357 /* 358 All dynamically allocated data structures for this stream are freed. 359 This function discards any unprocessed input and does not flush any pending 360 output. 361 362 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 363 stream state was inconsistent, Z_DATA_ERROR if the stream was freed 364 prematurely (some input or output was discarded). In the error case, msg 365 may be set but then points to a static string (which must not be 366 deallocated). 367 */ 368 369 370 /* 371 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); 372 373 Initializes the internal stream state for decompression. The fields 374 next_in, avail_in, zalloc, zfree and opaque must be initialized before by 375 the caller. If next_in is not Z_NULL and avail_in is large enough (the 376 exact value depends on the compression method), inflateInit determines the 377 compression method from the zlib header and allocates all data structures 378 accordingly; otherwise the allocation will be deferred to the first call of 379 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to 380 use default allocation functions. 381 382 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 383 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 384 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 385 invalid, such as a null pointer to the structure. msg is set to null if 386 there is no error message. inflateInit does not perform any decompression 387 apart from possibly reading the zlib header if present: actual decompression 388 will be done by inflate(). (So next_in and avail_in may be modified, but 389 next_out and avail_out are unused and unchanged.) The current implementation 390 of inflateInit() does not process any header information -- that is deferred 391 until inflate() is called. 392 */ 393 394 395 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); 396 /* 397 inflate decompresses as much data as possible, and stops when the input 398 buffer becomes empty or the output buffer becomes full. It may introduce 399 some output latency (reading input without producing any output) except when 400 forced to flush. 401 402 The detailed semantics are as follows. inflate performs one or both of the 403 following actions: 404 405 - Decompress more input starting at next_in and update next_in and avail_in 406 accordingly. If not all input can be processed (because there is not 407 enough room in the output buffer), next_in is updated and processing will 408 resume at this point for the next call of inflate(). 409 410 - Provide more output starting at next_out and update next_out and avail_out 411 accordingly. inflate() provides as much output as possible, until there is 412 no more input data or no more space in the output buffer (see below about 413 the flush parameter). 414 415 Before the call of inflate(), the application should ensure that at least 416 one of the actions is possible, by providing more input and/or consuming more 417 output, and updating the next_* and avail_* values accordingly. The 418 application can consume the uncompressed output when it wants, for example 419 when the output buffer is full (avail_out == 0), or after each call of 420 inflate(). If inflate returns Z_OK and with zero avail_out, it must be 421 called again after making room in the output buffer because there might be 422 more output pending. 423 424 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, 425 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much 426 output as possible to the output buffer. Z_BLOCK requests that inflate() 427 stop if and when it gets to the next deflate block boundary. When decoding 428 the zlib or gzip format, this will cause inflate() to return immediately 429 after the header and before the first block. When doing a raw inflate, 430 inflate() will go ahead and process the first block, and will return when it 431 gets to the end of that block, or when it runs out of data. 432 433 The Z_BLOCK option assists in appending to or combining deflate streams. 434 Also to assist in this, on return inflate() will set strm->data_type to the 435 number of unused bits in the last byte taken from strm->next_in, plus 64 if 436 inflate() is currently decoding the last block in the deflate stream, plus 437 128 if inflate() returned immediately after decoding an end-of-block code or 438 decoding the complete header up to just before the first byte of the deflate 439 stream. The end-of-block will not be indicated until all of the uncompressed 440 data from that block has been written to strm->next_out. The number of 441 unused bits may in general be greater than seven, except when bit 7 of 442 data_type is set, in which case the number of unused bits will be less than 443 eight. data_type is set as noted here every time inflate() returns for all 444 flush options, and so can be used to determine the amount of currently 445 consumed input in bits. 446 447 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the 448 end of each deflate block header is reached, before any actual data in that 449 block is decoded. This allows the caller to determine the length of the 450 deflate block header for later use in random access within a deflate block. 451 256 is added to the value of strm->data_type when inflate() returns 452 immediately after reaching the end of the deflate block header. 453 454 inflate() should normally be called until it returns Z_STREAM_END or an 455 error. However if all decompression is to be performed in a single step (a 456 single call of inflate), the parameter flush should be set to Z_FINISH. In 457 this case all pending input is processed and all pending output is flushed; 458 avail_out must be large enough to hold all of the uncompressed data for the 459 operation to complete. (The size of the uncompressed data may have been 460 saved by the compressor for this purpose.) The use of Z_FINISH is not 461 required to perform an inflation in one step. However it may be used to 462 inform inflate that a faster approach can be used for the single inflate() 463 call. Z_FINISH also informs inflate to not maintain a sliding window if the 464 stream completes, which reduces inflate's memory footprint. If the stream 465 does not complete, either because not all of the stream is provided or not 466 enough output space is provided, then a sliding window will be allocated and 467 inflate() can be called again to continue the operation as if Z_NO_FLUSH had 468 been used. 469 470 In this implementation, inflate() always flushes as much output as 471 possible to the output buffer, and always uses the faster approach on the 472 first call. So the effects of the flush parameter in this implementation are 473 on the return value of inflate() as noted below, when inflate() returns early 474 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of 475 memory for a sliding window when Z_FINISH is used. 476 477 If a preset dictionary is needed after this call (see inflateSetDictionary 478 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary 479 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 480 strm->adler to the Adler-32 checksum of all output produced so far (that is, 481 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 482 below. At the end of the stream, inflate() checks that its computed adler32 483 checksum is equal to that saved by the compressor and returns Z_STREAM_END 484 only if the checksum is correct. 485 486 inflate() can decompress and check either zlib-wrapped or gzip-wrapped 487 deflate data. The header type is detected automatically, if requested when 488 initializing with inflateInit2(). Any information contained in the gzip 489 header is not retained, so applications that need that information should 490 instead use raw inflate, see inflateInit2() below, or inflateBack() and 491 perform their own processing of the gzip header and trailer. When processing 492 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output 493 producted so far. The CRC-32 is checked against the gzip trailer. 494 495 inflate() returns Z_OK if some progress has been made (more input processed 496 or more output produced), Z_STREAM_END if the end of the compressed data has 497 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 498 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 499 corrupted (input stream not conforming to the zlib format or incorrect check 500 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example 501 next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory, 502 Z_BUF_ERROR if no progress is possible or if there was not enough room in the 503 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 504 inflate() can be called again with more input and more output space to 505 continue decompressing. If Z_DATA_ERROR is returned, the application may 506 then call inflateSync() to look for a good compression block if a partial 507 recovery of the data is desired. 508 */ 509 510 511 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); 512 /* 513 All dynamically allocated data structures for this stream are freed. 514 This function discards any unprocessed input and does not flush any pending 515 output. 516 517 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 518 was inconsistent. In the error case, msg may be set but then points to a 519 static string (which must not be deallocated). 520 */ 521 522 523 /* Advanced functions */ 524 525 /* 526 The following functions are needed only in some special applications. 527 */ 528 529 /* 530 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, 531 int level, 532 int method, 533 int windowBits, 534 int memLevel, 535 int strategy)); 536 537 This is another version of deflateInit with more compression options. The 538 fields next_in, zalloc, zfree and opaque must be initialized before by the 539 caller. 540 541 The method parameter is the compression method. It must be Z_DEFLATED in 542 this version of the library. 543 544 The windowBits parameter is the base two logarithm of the window size 545 (the size of the history buffer). It should be in the range 8..15 for this 546 version of the library. Larger values of this parameter result in better 547 compression at the expense of memory usage. The default value is 15 if 548 deflateInit is used instead. 549 550 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits 551 determines the window size. deflate() will then generate raw deflate data 552 with no zlib header or trailer, and will not compute an adler32 check value. 553 554 windowBits can also be greater than 15 for optional gzip encoding. Add 555 16 to windowBits to write a simple gzip header and trailer around the 556 compressed data instead of a zlib wrapper. The gzip header will have no 557 file name, no extra data, no comment, no modification time (set to zero), no 558 header crc, and the operating system will be set to 255 (unknown). If a 559 gzip stream is being written, strm->adler is a crc32 instead of an adler32. 560 561 The memLevel parameter specifies how much memory should be allocated 562 for the internal compression state. memLevel=1 uses minimum memory but is 563 slow and reduces compression ratio; memLevel=9 uses maximum memory for 564 optimal speed. The default value is 8. See zconf.h for total memory usage 565 as a function of windowBits and memLevel. 566 567 The strategy parameter is used to tune the compression algorithm. Use the 568 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 569 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no 570 string match), or Z_RLE to limit match distances to one (run-length 571 encoding). Filtered data consists mostly of small values with a somewhat 572 random distribution. In this case, the compression algorithm is tuned to 573 compress them better. The effect of Z_FILTERED is to force more Huffman 574 coding and less string matching; it is somewhat intermediate between 575 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as 576 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The 577 strategy parameter only affects the compression ratio but not the 578 correctness of the compressed output even if it is not set appropriately. 579 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler 580 decoder for special applications. 581 582 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 583 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid 584 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is 585 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is 586 set to null if there is no error message. deflateInit2 does not perform any 587 compression: this will be done by deflate(). 588 */ 589 590 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, 591 const Bytef *dictionary, 592 uInt dictLength)); 593 /* 594 Initializes the compression dictionary from the given byte sequence 595 without producing any compressed output. When using the zlib format, this 596 function must be called immediately after deflateInit, deflateInit2 or 597 deflateReset, and before any call of deflate. When doing raw deflate, this 598 function must be called either before any call of deflate, or immediately 599 after the completion of a deflate block, i.e. after all input has been 600 consumed and all output has been delivered when using any of the flush 601 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The 602 compressor and decompressor must use exactly the same dictionary (see 603 inflateSetDictionary). 604 605 The dictionary should consist of strings (byte sequences) that are likely 606 to be encountered later in the data to be compressed, with the most commonly 607 used strings preferably put towards the end of the dictionary. Using a 608 dictionary is most useful when the data to be compressed is short and can be 609 predicted with good accuracy; the data can then be compressed better than 610 with the default empty dictionary. 611 612 Depending on the size of the compression data structures selected by 613 deflateInit or deflateInit2, a part of the dictionary may in effect be 614 discarded, for example if the dictionary is larger than the window size 615 provided in deflateInit or deflateInit2. Thus the strings most likely to be 616 useful should be put at the end of the dictionary, not at the front. In 617 addition, the current implementation of deflate will use at most the window 618 size minus 262 bytes of the provided dictionary. 619 620 Upon return of this function, strm->adler is set to the adler32 value 621 of the dictionary; the decompressor may later use this value to determine 622 which dictionary has been used by the compressor. (The adler32 value 623 applies to the whole dictionary even if only a subset of the dictionary is 624 actually used by the compressor.) If a raw deflate was requested, then the 625 adler32 value is not computed and strm->adler is not set. 626 627 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 628 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is 629 inconsistent (for example if deflate has already been called for this stream 630 or if not at a block boundary for raw deflate). deflateSetDictionary does 631 not perform any compression: this will be done by deflate(). 632 */ 633 634 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, 635 z_streamp source)); 636 /* 637 Sets the destination stream as a complete copy of the source stream. 638 639 This function can be useful when several compression strategies will be 640 tried, for example when there are several ways of pre-processing the input 641 data with a filter. The streams that will be discarded should then be freed 642 by calling deflateEnd. Note that deflateCopy duplicates the internal 643 compression state which can be quite large, so this strategy is slow and can 644 consume lots of memory. 645 646 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 647 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 648 (such as zalloc being Z_NULL). msg is left unchanged in both source and 649 destination. 650 */ 651 652 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); 653 /* 654 This function is equivalent to deflateEnd followed by deflateInit, 655 but does not free and reallocate all the internal compression state. The 656 stream will keep the same compression level and any other attributes that 657 may have been set by deflateInit2. 658 659 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 660 stream state was inconsistent (such as zalloc or state being Z_NULL). 661 */ 662 663 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, 664 int level, 665 int strategy)); 666 /* 667 Dynamically update the compression level and compression strategy. The 668 interpretation of level and strategy is as in deflateInit2. This can be 669 used to switch between compression and straight copy of the input data, or 670 to switch to a different kind of input data requiring a different strategy. 671 If the compression level is changed, the input available so far is 672 compressed with the old level (and may be flushed); the new level will take 673 effect only at the next call of deflate(). 674 675 Before the call of deflateParams, the stream state must be set as for 676 a call of deflate(), since the currently available input may have to be 677 compressed and flushed. In particular, strm->avail_out must be non-zero. 678 679 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source 680 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if 681 strm->avail_out was zero. 682 */ 683 684 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, 685 int good_length, 686 int max_lazy, 687 int nice_length, 688 int max_chain)); 689 /* 690 Fine tune deflate's internal compression parameters. This should only be 691 used by someone who understands the algorithm used by zlib's deflate for 692 searching for the best matching string, and even then only by the most 693 fanatic optimizer trying to squeeze out the last compressed bit for their 694 specific input data. Read the deflate.c source code for the meaning of the 695 max_lazy, good_length, nice_length, and max_chain parameters. 696 697 deflateTune() can be called after deflateInit() or deflateInit2(), and 698 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. 699 */ 700 701 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, 702 uLong sourceLen)); 703 /* 704 deflateBound() returns an upper bound on the compressed size after 705 deflation of sourceLen bytes. It must be called after deflateInit() or 706 deflateInit2(), and after deflateSetHeader(), if used. This would be used 707 to allocate an output buffer for deflation in a single pass, and so would be 708 called before deflate(). If that first deflate() call is provided the 709 sourceLen input bytes, an output buffer allocated to the size returned by 710 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed 711 to return Z_STREAM_END. Note that it is possible for the compressed size to 712 be larger than the value returned by deflateBound() if flush options other 713 than Z_FINISH or Z_NO_FLUSH are used. 714 */ 715 716 ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm, 717 unsigned *pending, 718 int *bits)); 719 /* 720 deflatePending() returns the number of bytes and bits of output that have 721 been generated, but not yet provided in the available output. The bytes not 722 provided would be due to the available output space having being consumed. 723 The number of bits of output not provided are between 0 and 7, where they 724 await more bits to join them in order to fill out a full byte. If pending 725 or bits are Z_NULL, then those values are not set. 726 727 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source 728 stream state was inconsistent. 729 */ 730 731 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, 732 int bits, 733 int value)); 734 /* 735 deflatePrime() inserts bits in the deflate output stream. The intent 736 is that this function is used to start off the deflate output with the bits 737 leftover from a previous deflate stream when appending to it. As such, this 738 function can only be used for raw deflate, and must be used before the first 739 deflate() call after a deflateInit2() or deflateReset(). bits must be less 740 than or equal to 16, and that many of the least significant bits of value 741 will be inserted in the output. 742 743 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough 744 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the 745 source stream state was inconsistent. 746 */ 747 748 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, 749 gz_headerp head)); 750 /* 751 deflateSetHeader() provides gzip header information for when a gzip 752 stream is requested by deflateInit2(). deflateSetHeader() may be called 753 after deflateInit2() or deflateReset() and before the first call of 754 deflate(). The text, time, os, extra field, name, and comment information 755 in the provided gz_header structure are written to the gzip header (xflag is 756 ignored -- the extra flags are set according to the compression level). The 757 caller must assure that, if not Z_NULL, name and comment are terminated with 758 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are 759 available there. If hcrc is true, a gzip header crc is included. Note that 760 the current versions of the command-line version of gzip (up through version 761 1.3.x) do not support header crc's, and will report that it is a "multi-part 762 gzip file" and give up. 763 764 If deflateSetHeader is not used, the default gzip header has text false, 765 the time set to zero, and os set to 255, with no extra, name, or comment 766 fields. The gzip header is returned to the default state by deflateReset(). 767 768 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 769 stream state was inconsistent. 770 */ 771 772 /* 773 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, 774 int windowBits)); 775 776 This is another version of inflateInit with an extra parameter. The 777 fields next_in, avail_in, zalloc, zfree and opaque must be initialized 778 before by the caller. 779 780 The windowBits parameter is the base two logarithm of the maximum window 781 size (the size of the history buffer). It should be in the range 8..15 for 782 this version of the library. The default value is 15 if inflateInit is used 783 instead. windowBits must be greater than or equal to the windowBits value 784 provided to deflateInit2() while compressing, or it must be equal to 15 if 785 deflateInit2() was not used. If a compressed stream with a larger window 786 size is given as input, inflate() will return with the error code 787 Z_DATA_ERROR instead of trying to allocate a larger window. 788 789 windowBits can also be zero to request that inflate use the window size in 790 the zlib header of the compressed stream. 791 792 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits 793 determines the window size. inflate() will then process raw deflate data, 794 not looking for a zlib or gzip header, not generating a check value, and not 795 looking for any check values for comparison at the end of the stream. This 796 is for use with other formats that use the deflate compressed data format 797 such as zip. Those formats provide their own check values. If a custom 798 format is developed using the raw deflate format for compressed data, it is 799 recommended that a check value such as an adler32 or a crc32 be applied to 800 the uncompressed data as is done in the zlib, gzip, and zip formats. For 801 most applications, the zlib format should be used as is. Note that comments 802 above on the use in deflateInit2() applies to the magnitude of windowBits. 803 804 windowBits can also be greater than 15 for optional gzip decoding. Add 805 32 to windowBits to enable zlib and gzip decoding with automatic header 806 detection, or add 16 to decode only the gzip format (the zlib format will 807 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a 808 crc32 instead of an adler32. 809 810 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 811 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 812 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 813 invalid, such as a null pointer to the structure. msg is set to null if 814 there is no error message. inflateInit2 does not perform any decompression 815 apart from possibly reading the zlib header if present: actual decompression 816 will be done by inflate(). (So next_in and avail_in may be modified, but 817 next_out and avail_out are unused and unchanged.) The current implementation 818 of inflateInit2() does not process any header information -- that is 819 deferred until inflate() is called. 820 */ 821 822 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, 823 const Bytef *dictionary, 824 uInt dictLength)); 825 /* 826 Initializes the decompression dictionary from the given uncompressed byte 827 sequence. This function must be called immediately after a call of inflate, 828 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor 829 can be determined from the adler32 value returned by that call of inflate. 830 The compressor and decompressor must use exactly the same dictionary (see 831 deflateSetDictionary). For raw inflate, this function can be called at any 832 time to set the dictionary. If the provided dictionary is smaller than the 833 window and there is already data in the window, then the provided dictionary 834 will amend what's there. The application must insure that the dictionary 835 that was used for compression is provided. 836 837 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 838 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is 839 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 840 expected one (incorrect adler32 value). inflateSetDictionary does not 841 perform any decompression: this will be done by subsequent calls of 842 inflate(). 843 */ 844 845 ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm, 846 Bytef *dictionary, 847 uInt *dictLength)); 848 /* 849 Returns the sliding dictionary being maintained by inflate. dictLength is 850 set to the number of bytes in the dictionary, and that many bytes are copied 851 to dictionary. dictionary must have enough space, where 32768 bytes is 852 always enough. If inflateGetDictionary() is called with dictionary equal to 853 Z_NULL, then only the dictionary length is returned, and nothing is copied. 854 Similary, if dictLength is Z_NULL, then it is not set. 855 856 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the 857 stream state is inconsistent. 858 */ 859 860 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); 861 /* 862 Skips invalid compressed data until a possible full flush point (see above 863 for the description of deflate with Z_FULL_FLUSH) can be found, or until all 864 available input is skipped. No output is provided. 865 866 inflateSync searches for a 00 00 FF FF pattern in the compressed data. 867 All full flush points have this pattern, but not all occurrences of this 868 pattern are full flush points. 869 870 inflateSync returns Z_OK if a possible full flush point has been found, 871 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point 872 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. 873 In the success case, the application may save the current current value of 874 total_in which indicates where valid compressed data was found. In the 875 error case, the application may repeatedly call inflateSync, providing more 876 input each time, until success or end of the input data. 877 */ 878 879 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, 880 z_streamp source)); 881 /* 882 Sets the destination stream as a complete copy of the source stream. 883 884 This function can be useful when randomly accessing a large stream. The 885 first pass through the stream can periodically record the inflate state, 886 allowing restarting inflate at those points when randomly accessing the 887 stream. 888 889 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 890 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 891 (such as zalloc being Z_NULL). msg is left unchanged in both source and 892 destination. 893 */ 894 895 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); 896 /* 897 This function is equivalent to inflateEnd followed by inflateInit, 898 but does not free and reallocate all the internal decompression state. The 899 stream will keep attributes that may have been set by inflateInit2. 900 901 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 902 stream state was inconsistent (such as zalloc or state being Z_NULL). 903 */ 904 905 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, 906 int windowBits)); 907 /* 908 This function is the same as inflateReset, but it also permits changing 909 the wrap and window size requests. The windowBits parameter is interpreted 910 the same as it is for inflateInit2. 911 912 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source 913 stream state was inconsistent (such as zalloc or state being Z_NULL), or if 914 the windowBits parameter is invalid. 915 */ 916 917 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, 918 int bits, 919 int value)); 920 /* 921 This function inserts bits in the inflate input stream. The intent is 922 that this function is used to start inflating at a bit position in the 923 middle of a byte. The provided bits will be used before any bytes are used 924 from next_in. This function should only be used with raw inflate, and 925 should be used before the first inflate() call after inflateInit2() or 926 inflateReset(). bits must be less than or equal to 16, and that many of the 927 least significant bits of value will be inserted in the input. 928 929 If bits is negative, then the input stream bit buffer is emptied. Then 930 inflatePrime() can be called again to put bits in the buffer. This is used 931 to clear out bits leftover after feeding inflate a block description prior 932 to feeding inflate codes. 933 934 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source 935 stream state was inconsistent. 936 */ 937 938 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); 939 /* 940 This function returns two values, one in the lower 16 bits of the return 941 value, and the other in the remaining upper bits, obtained by shifting the 942 return value down 16 bits. If the upper value is -1 and the lower value is 943 zero, then inflate() is currently decoding information outside of a block. 944 If the upper value is -1 and the lower value is non-zero, then inflate is in 945 the middle of a stored block, with the lower value equaling the number of 946 bytes from the input remaining to copy. If the upper value is not -1, then 947 it is the number of bits back from the current bit position in the input of 948 the code (literal or length/distance pair) currently being processed. In 949 that case the lower value is the number of bytes already emitted for that 950 code. 951 952 A code is being processed if inflate is waiting for more input to complete 953 decoding of the code, or if it has completed decoding but is waiting for 954 more output space to write the literal or match data. 955 956 inflateMark() is used to mark locations in the input data for random 957 access, which may be at bit positions, and to note those cases where the 958 output of a code may span boundaries of random access blocks. The current 959 location in the input stream can be determined from avail_in and data_type 960 as noted in the description for the Z_BLOCK flush parameter for inflate. 961 962 inflateMark returns the value noted above or -1 << 16 if the provided 963 source stream state was inconsistent. 964 */ 965 966 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, 967 gz_headerp head)); 968 /* 969 inflateGetHeader() requests that gzip header information be stored in the 970 provided gz_header structure. inflateGetHeader() may be called after 971 inflateInit2() or inflateReset(), and before the first call of inflate(). 972 As inflate() processes the gzip stream, head->done is zero until the header 973 is completed, at which time head->done is set to one. If a zlib stream is 974 being decoded, then head->done is set to -1 to indicate that there will be 975 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be 976 used to force inflate() to return immediately after header processing is 977 complete and before any actual data is decompressed. 978 979 The text, time, xflags, and os fields are filled in with the gzip header 980 contents. hcrc is set to true if there is a header CRC. (The header CRC 981 was valid if done is set to one.) If extra is not Z_NULL, then extra_max 982 contains the maximum number of bytes to write to extra. Once done is true, 983 extra_len contains the actual extra field length, and extra contains the 984 extra field, or that field truncated if extra_max is less than extra_len. 985 If name is not Z_NULL, then up to name_max characters are written there, 986 terminated with a zero unless the length is greater than name_max. If 987 comment is not Z_NULL, then up to comm_max characters are written there, 988 terminated with a zero unless the length is greater than comm_max. When any 989 of extra, name, or comment are not Z_NULL and the respective field is not 990 present in the header, then that field is set to Z_NULL to signal its 991 absence. This allows the use of deflateSetHeader() with the returned 992 structure to duplicate the header. However if those fields are set to 993 allocated memory, then the application will need to save those pointers 994 elsewhere so that they can be eventually freed. 995 996 If inflateGetHeader is not used, then the header information is simply 997 discarded. The header is always checked for validity, including the header 998 CRC if present. inflateReset() will reset the process to discard the header 999 information. The application would need to call inflateGetHeader() again to 1000 retrieve the header from the next gzip stream. 1001 1002 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 1003 stream state was inconsistent. 1004 */ 1005 1006 /* 1007 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, 1008 unsigned char FAR *window)); 1009 1010 Initialize the internal stream state for decompression using inflateBack() 1011 calls. The fields zalloc, zfree and opaque in strm must be initialized 1012 before the call. If zalloc and zfree are Z_NULL, then the default library- 1013 derived memory allocation routines are used. windowBits is the base two 1014 logarithm of the window size, in the range 8..15. window is a caller 1015 supplied buffer of that size. Except for special applications where it is 1016 assured that deflate was used with small window sizes, windowBits must be 15 1017 and a 32K byte window must be supplied to be able to decompress general 1018 deflate streams. 1019 1020 See inflateBack() for the usage of these routines. 1021 1022 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of 1023 the parameters are invalid, Z_MEM_ERROR if the internal state could not be 1024 allocated, or Z_VERSION_ERROR if the version of the library does not match 1025 the version of the header file. 1026 */ 1027 1028 typedef unsigned (*in_func) OF((void FAR *, 1029 z_const unsigned char FAR * FAR *)); 1030 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); 1031 1032 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, 1033 in_func in, void FAR *in_desc, 1034 out_func out, void FAR *out_desc)); 1035 /* 1036 inflateBack() does a raw inflate with a single call using a call-back 1037 interface for input and output. This is potentially more efficient than 1038 inflate() for file i/o applications, in that it avoids copying between the 1039 output and the sliding window by simply making the window itself the output 1040 buffer. inflate() can be faster on modern CPUs when used with large 1041 buffers. inflateBack() trusts the application to not change the output 1042 buffer passed by the output function, at least until inflateBack() returns. 1043 1044 inflateBackInit() must be called first to allocate the internal state 1045 and to initialize the state with the user-provided window buffer. 1046 inflateBack() may then be used multiple times to inflate a complete, raw 1047 deflate stream with each call. inflateBackEnd() is then called to free the 1048 allocated state. 1049 1050 A raw deflate stream is one with no zlib or gzip header or trailer. 1051 This routine would normally be used in a utility that reads zip or gzip 1052 files and writes out uncompressed files. The utility would decode the 1053 header and process the trailer on its own, hence this routine expects only 1054 the raw deflate stream to decompress. This is different from the normal 1055 behavior of inflate(), which expects either a zlib or gzip header and 1056 trailer around the deflate stream. 1057 1058 inflateBack() uses two subroutines supplied by the caller that are then 1059 called by inflateBack() for input and output. inflateBack() calls those 1060 routines until it reads a complete deflate stream and writes out all of the 1061 uncompressed data, or until it encounters an error. The function's 1062 parameters and return types are defined above in the in_func and out_func 1063 typedefs. inflateBack() will call in(in_desc, &buf) which should return the 1064 number of bytes of provided input, and a pointer to that input in buf. If 1065 there is no input available, in() must return zero--buf is ignored in that 1066 case--and inflateBack() will return a buffer error. inflateBack() will call 1067 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() 1068 should return zero on success, or non-zero on failure. If out() returns 1069 non-zero, inflateBack() will return with an error. Neither in() nor out() 1070 are permitted to change the contents of the window provided to 1071 inflateBackInit(), which is also the buffer that out() uses to write from. 1072 The length written by out() will be at most the window size. Any non-zero 1073 amount of input may be provided by in(). 1074 1075 For convenience, inflateBack() can be provided input on the first call by 1076 setting strm->next_in and strm->avail_in. If that input is exhausted, then 1077 in() will be called. Therefore strm->next_in must be initialized before 1078 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called 1079 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in 1080 must also be initialized, and then if strm->avail_in is not zero, input will 1081 initially be taken from strm->next_in[0 .. strm->avail_in - 1]. 1082 1083 The in_desc and out_desc parameters of inflateBack() is passed as the 1084 first parameter of in() and out() respectively when they are called. These 1085 descriptors can be optionally used to pass any information that the caller- 1086 supplied in() and out() functions need to do their job. 1087 1088 On return, inflateBack() will set strm->next_in and strm->avail_in to 1089 pass back any unused input that was provided by the last in() call. The 1090 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR 1091 if in() or out() returned an error, Z_DATA_ERROR if there was a format error 1092 in the deflate stream (in which case strm->msg is set to indicate the nature 1093 of the error), or Z_STREAM_ERROR if the stream was not properly initialized. 1094 In the case of Z_BUF_ERROR, an input or output error can be distinguished 1095 using strm->next_in which will be Z_NULL only if in() returned an error. If 1096 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning 1097 non-zero. (in() will always be called before out(), so strm->next_in is 1098 assured to be defined if out() returns non-zero.) Note that inflateBack() 1099 cannot return Z_OK. 1100 */ 1101 1102 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); 1103 /* 1104 All memory allocated by inflateBackInit() is freed. 1105 1106 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream 1107 state was inconsistent. 1108 */ 1109 1110 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); 1111 /* Return flags indicating compile-time options. 1112 1113 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: 1114 1.0: size of uInt 1115 3.2: size of uLong 1116 5.4: size of voidpf (pointer) 1117 7.6: size of z_off_t 1118 1119 Compiler, assembler, and debug options: 1120 8: DEBUG 1121 9: ASMV or ASMINF -- use ASM code 1122 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention 1123 11: 0 (reserved) 1124 1125 One-time table building (smaller code, but not thread-safe if true): 1126 12: BUILDFIXED -- build static block decoding tables when needed 1127 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed 1128 14,15: 0 (reserved) 1129 1130 Library content (indicates missing functionality): 1131 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking 1132 deflate code when not needed) 1133 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect 1134 and decode gzip streams (to avoid linking crc code) 1135 18-19: 0 (reserved) 1136 1137 Operation variations (changes in library functionality): 1138 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate 1139 21: FASTEST -- deflate algorithm with only one, lowest compression level 1140 22,23: 0 (reserved) 1141 1142 The sprintf variant used by gzprintf (zero is best): 1143 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format 1144 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! 1145 26: 0 = returns value, 1 = void -- 1 means inferred string length returned 1146 1147 Remainder: 1148 27-31: 0 (reserved) 1149 */ 1150 1151 #ifndef Z_SOLO 1152 1153 /* utility functions */ 1154 1155 /* 1156 The following utility functions are implemented on top of the basic 1157 stream-oriented functions. To simplify the interface, some default options 1158 are assumed (compression level and memory usage, standard memory allocation 1159 functions). The source code of these utility functions can be modified if 1160 you need special options. 1161 */ 1162 1163 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, 1164 const Bytef *source, uLong sourceLen)); 1165 /* 1166 Compresses the source buffer into the destination buffer. sourceLen is 1167 the byte length of the source buffer. Upon entry, destLen is the total size 1168 of the destination buffer, which must be at least the value returned by 1169 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1170 compressed buffer. 1171 1172 compress returns Z_OK if success, Z_MEM_ERROR if there was not 1173 enough memory, Z_BUF_ERROR if there was not enough room in the output 1174 buffer. 1175 */ 1176 1177 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, 1178 const Bytef *source, uLong sourceLen, 1179 int level)); 1180 /* 1181 Compresses the source buffer into the destination buffer. The level 1182 parameter has the same meaning as in deflateInit. sourceLen is the byte 1183 length of the source buffer. Upon entry, destLen is the total size of the 1184 destination buffer, which must be at least the value returned by 1185 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1186 compressed buffer. 1187 1188 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 1189 memory, Z_BUF_ERROR if there was not enough room in the output buffer, 1190 Z_STREAM_ERROR if the level parameter is invalid. 1191 */ 1192 1193 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); 1194 /* 1195 compressBound() returns an upper bound on the compressed size after 1196 compress() or compress2() on sourceLen bytes. It would be used before a 1197 compress() or compress2() call to allocate the destination buffer. 1198 */ 1199 1200 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, 1201 const Bytef *source, uLong sourceLen)); 1202 /* 1203 Decompresses the source buffer into the destination buffer. sourceLen is 1204 the byte length of the source buffer. Upon entry, destLen is the total size 1205 of the destination buffer, which must be large enough to hold the entire 1206 uncompressed data. (The size of the uncompressed data must have been saved 1207 previously by the compressor and transmitted to the decompressor by some 1208 mechanism outside the scope of this compression library.) Upon exit, destLen 1209 is the actual size of the uncompressed buffer. 1210 1211 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 1212 enough memory, Z_BUF_ERROR if there was not enough room in the output 1213 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In 1214 the case where there is not enough room, uncompress() will fill the output 1215 buffer with the uncompressed data up to that point. 1216 */ 1217 1218 /* gzip file access functions */ 1219 1220 /* 1221 This library supports reading and writing files in gzip (.gz) format with 1222 an interface similar to that of stdio, using the functions that start with 1223 "gz". The gzip format is different from the zlib format. gzip is a gzip 1224 wrapper, documented in RFC 1952, wrapped around a deflate stream. 1225 */ 1226 1227 typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ 1228 1229 /* 1230 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); 1231 1232 Opens a gzip (.gz) file for reading or writing. The mode parameter is as 1233 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or 1234 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only 1235 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' 1236 for fixed code compression as in "wb9F". (See the description of 1237 deflateInit2 for more information about the strategy parameter.) 'T' will 1238 request transparent writing or appending with no compression and not using 1239 the gzip format. 1240 1241 "a" can be used instead of "w" to request that the gzip stream that will 1242 be written be appended to the file. "+" will result in an error, since 1243 reading and writing to the same gzip file is not supported. The addition of 1244 "x" when writing will create the file exclusively, which fails if the file 1245 already exists. On systems that support it, the addition of "e" when 1246 reading or writing will set the flag to close the file on an execve() call. 1247 1248 These functions, as well as gzip, will read and decode a sequence of gzip 1249 streams in a file. The append function of gzopen() can be used to create 1250 such a file. (Also see gzflush() for another way to do this.) When 1251 appending, gzopen does not test whether the file begins with a gzip stream, 1252 nor does it look for the end of the gzip streams to begin appending. gzopen 1253 will simply append a gzip stream to the existing file. 1254 1255 gzopen can be used to read a file which is not in gzip format; in this 1256 case gzread will directly read from the file without decompression. When 1257 reading, this will be detected automatically by looking for the magic two- 1258 byte gzip header. 1259 1260 gzopen returns NULL if the file could not be opened, if there was 1261 insufficient memory to allocate the gzFile state, or if an invalid mode was 1262 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). 1263 errno can be checked to determine if the reason gzopen failed was that the 1264 file could not be opened. 1265 */ 1266 1267 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); 1268 /* 1269 gzdopen associates a gzFile with the file descriptor fd. File descriptors 1270 are obtained from calls like open, dup, creat, pipe or fileno (if the file 1271 has been previously opened with fopen). The mode parameter is as in gzopen. 1272 1273 The next call of gzclose on the returned gzFile will also close the file 1274 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor 1275 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, 1276 mode);. The duplicated descriptor should be saved to avoid a leak, since 1277 gzdopen does not close fd if it fails. If you are using fileno() to get the 1278 file descriptor from a FILE *, then you will have to use dup() to avoid 1279 double-close()ing the file descriptor. Both gzclose() and fclose() will 1280 close the associated file descriptor, so they need to have different file 1281 descriptors. 1282 1283 gzdopen returns NULL if there was insufficient memory to allocate the 1284 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not 1285 provided, or '+' was provided), or if fd is -1. The file descriptor is not 1286 used until the next gz* read, write, seek, or close operation, so gzdopen 1287 will not detect if fd is invalid (unless fd is -1). 1288 */ 1289 1290 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); 1291 /* 1292 Set the internal buffer size used by this library's functions. The 1293 default buffer size is 8192 bytes. This function must be called after 1294 gzopen() or gzdopen(), and before any other calls that read or write the 1295 file. The buffer memory allocation is always deferred to the first read or 1296 write. Two buffers are allocated, either both of the specified size when 1297 writing, or one of the specified size and the other twice that size when 1298 reading. A larger buffer size of, for example, 64K or 128K bytes will 1299 noticeably increase the speed of decompression (reading). 1300 1301 The new buffer size also affects the maximum length for gzprintf(). 1302 1303 gzbuffer() returns 0 on success, or -1 on failure, such as being called 1304 too late. 1305 */ 1306 1307 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); 1308 /* 1309 Dynamically update the compression level or strategy. See the description 1310 of deflateInit2 for the meaning of these parameters. 1311 1312 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not 1313 opened for writing. 1314 */ 1315 1316 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); 1317 /* 1318 Reads the given number of uncompressed bytes from the compressed file. If 1319 the input file is not in gzip format, gzread copies the given number of 1320 bytes into the buffer directly from the file. 1321 1322 After reaching the end of a gzip stream in the input, gzread will continue 1323 to read, looking for another gzip stream. Any number of gzip streams may be 1324 concatenated in the input file, and will all be decompressed by gzread(). 1325 If something other than a gzip stream is encountered after a gzip stream, 1326 that remaining trailing garbage is ignored (and no error is returned). 1327 1328 gzread can be used to read a gzip file that is being concurrently written. 1329 Upon reaching the end of the input, gzread will return with the available 1330 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then 1331 gzclearerr can be used to clear the end of file indicator in order to permit 1332 gzread to be tried again. Z_OK indicates that a gzip stream was completed 1333 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the 1334 middle of a gzip stream. Note that gzread does not return -1 in the event 1335 of an incomplete gzip stream. This error is deferred until gzclose(), which 1336 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip 1337 stream. Alternatively, gzerror can be used before gzclose to detect this 1338 case. 1339 1340 gzread returns the number of uncompressed bytes actually read, less than 1341 len for end of file, or -1 for error. 1342 */ 1343 1344 ZEXTERN int ZEXPORT gzwrite OF((gzFile file, 1345 voidpc buf, unsigned len)); 1346 /* 1347 Writes the given number of uncompressed bytes into the compressed file. 1348 gzwrite returns the number of uncompressed bytes written or 0 in case of 1349 error. 1350 */ 1351 1352 ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...)) 1353 __attribute__((__format__(__printf__, 2, 3))) 1354 __attribute__((__nonnull__(1))); 1355 /* 1356 Converts, formats, and writes the arguments to the compressed file under 1357 control of the format string, as in fprintf. gzprintf returns the number of 1358 uncompressed bytes actually written, or 0 in case of error. The number of 1359 uncompressed bytes written is limited to 8191, or one less than the buffer 1360 size given to gzbuffer(). The caller should assure that this limit is not 1361 exceeded. If it is exceeded, then gzprintf() will return an error (0) with 1362 nothing written. In this case, there may also be a buffer overflow with 1363 unpredictable consequences, which is possible only if zlib was compiled with 1364 the insecure functions sprintf() or vsprintf() because the secure snprintf() 1365 or vsnprintf() functions were not available. This can be determined using 1366 zlibCompileFlags(). 1367 */ 1368 1369 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); 1370 /* 1371 Writes the given null-terminated string to the compressed file, excluding 1372 the terminating null character. 1373 1374 gzputs returns the number of characters written, or -1 in case of error. 1375 */ 1376 1377 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); 1378 /* 1379 Reads bytes from the compressed file until len-1 characters are read, or a 1380 newline character is read and transferred to buf, or an end-of-file 1381 condition is encountered. If any characters are read or if len == 1, the 1382 string is terminated with a null character. If no characters are read due 1383 to an end-of-file or len < 1, then the buffer is left untouched. 1384 1385 gzgets returns buf which is a null-terminated string, or it returns NULL 1386 for end-of-file or in case of error. If there was an error, the contents at 1387 buf are indeterminate. 1388 */ 1389 1390 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); 1391 /* 1392 Writes c, converted to an unsigned char, into the compressed file. gzputc 1393 returns the value that was written, or -1 in case of error. 1394 */ 1395 1396 ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); 1397 /* 1398 Reads one byte from the compressed file. gzgetc returns this byte or -1 1399 in case of end of file or error. This is implemented as a macro for speed. 1400 As such, it does not do all of the checking the other functions do. I.e. 1401 it does not check to see if file is NULL, nor whether the structure file 1402 points to has been clobbered or not. 1403 */ 1404 1405 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); 1406 /* 1407 Push one character back onto the stream to be read as the first character 1408 on the next read. At least one character of push-back is allowed. 1409 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will 1410 fail if c is -1, and may fail if a character has been pushed but not read 1411 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the 1412 output buffer size of pushed characters is allowed. (See gzbuffer above.) 1413 The pushed character will be discarded if the stream is repositioned with 1414 gzseek() or gzrewind(). 1415 */ 1416 1417 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); 1418 /* 1419 Flushes all pending output into the compressed file. The parameter flush 1420 is as in the deflate() function. The return value is the zlib error number 1421 (see function gzerror below). gzflush is only permitted when writing. 1422 1423 If the flush parameter is Z_FINISH, the remaining data is written and the 1424 gzip stream is completed in the output. If gzwrite() is called again, a new 1425 gzip stream will be started in the output. gzread() is able to read such 1426 concatented gzip streams. 1427 1428 gzflush should be called only when strictly necessary because it will 1429 degrade compression if called too often. 1430 */ 1431 1432 /* 1433 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, 1434 z_off_t offset, int whence)); 1435 1436 Sets the starting position for the next gzread or gzwrite on the given 1437 compressed file. The offset represents a number of bytes in the 1438 uncompressed data stream. The whence parameter is defined as in lseek(2); 1439 the value SEEK_END is not supported. 1440 1441 If the file is opened for reading, this function is emulated but can be 1442 extremely slow. If the file is opened for writing, only forward seeks are 1443 supported; gzseek then compresses a sequence of zeroes up to the new 1444 starting position. 1445 1446 gzseek returns the resulting offset location as measured in bytes from 1447 the beginning of the uncompressed stream, or -1 in case of error, in 1448 particular if the file is opened for writing and the new starting position 1449 would be before the current position. 1450 */ 1451 1452 ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); 1453 /* 1454 Rewinds the given file. This function is supported only for reading. 1455 1456 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) 1457 */ 1458 1459 /* 1460 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); 1461 1462 Returns the starting position for the next gzread or gzwrite on the given 1463 compressed file. This position represents a number of bytes in the 1464 uncompressed data stream, and is zero when starting, even if appending or 1465 reading a gzip stream from the middle of a file using gzdopen(). 1466 1467 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) 1468 */ 1469 1470 /* 1471 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); 1472 1473 Returns the current offset in the file being read or written. This offset 1474 includes the count of bytes that precede the gzip stream, for example when 1475 appending or when using gzdopen() for reading. When reading, the offset 1476 does not include as yet unused buffered input. This information can be used 1477 for a progress indicator. On error, gzoffset() returns -1. 1478 */ 1479 1480 ZEXTERN int ZEXPORT gzeof OF((gzFile file)); 1481 /* 1482 Returns true (1) if the end-of-file indicator has been set while reading, 1483 false (0) otherwise. Note that the end-of-file indicator is set only if the 1484 read tried to go past the end of the input, but came up short. Therefore, 1485 just like feof(), gzeof() may return false even if there is no more data to 1486 read, in the event that the last read request was for the exact number of 1487 bytes remaining in the input file. This will happen if the input file size 1488 is an exact multiple of the buffer size. 1489 1490 If gzeof() returns true, then the read functions will return no more data, 1491 unless the end-of-file indicator is reset by gzclearerr() and the input file 1492 has grown since the previous end of file was detected. 1493 */ 1494 1495 ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); 1496 /* 1497 Returns true (1) if file is being copied directly while reading, or false 1498 (0) if file is a gzip stream being decompressed. 1499 1500 If the input file is empty, gzdirect() will return true, since the input 1501 does not contain a gzip stream. 1502 1503 If gzdirect() is used immediately after gzopen() or gzdopen() it will 1504 cause buffers to be allocated to allow reading the file to determine if it 1505 is a gzip file. Therefore if gzbuffer() is used, it should be called before 1506 gzdirect(). 1507 1508 When writing, gzdirect() returns true (1) if transparent writing was 1509 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: 1510 gzdirect() is not needed when writing. Transparent writing must be 1511 explicitly requested, so the application already knows the answer. When 1512 linking statically, using gzdirect() will include all of the zlib code for 1513 gzip file reading and decompression, which may not be desired.) 1514 */ 1515 1516 ZEXTERN int ZEXPORT gzclose OF((gzFile file)); 1517 /* 1518 Flushes all pending output if necessary, closes the compressed file and 1519 deallocates the (de)compression state. Note that once file is closed, you 1520 cannot call gzerror with file, since its structures have been deallocated. 1521 gzclose must not be called more than once on the same file, just as free 1522 must not be called more than once on the same allocation. 1523 1524 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a 1525 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the 1526 last read ended in the middle of a gzip stream, or Z_OK on success. 1527 */ 1528 1529 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); 1530 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); 1531 /* 1532 Same as gzclose(), but gzclose_r() is only for use when reading, and 1533 gzclose_w() is only for use when writing or appending. The advantage to 1534 using these instead of gzclose() is that they avoid linking in zlib 1535 compression or decompression code that is not used when only reading or only 1536 writing respectively. If gzclose() is used, then both compression and 1537 decompression code will be included the application when linking to a static 1538 zlib library. 1539 */ 1540 1541 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); 1542 /* 1543 Returns the error message for the last error which occurred on the given 1544 compressed file. errnum is set to zlib error number. If an error occurred 1545 in the file system and not in the compression library, errnum is set to 1546 Z_ERRNO and the application may consult errno to get the exact error code. 1547 1548 The application must not modify the returned string. Future calls to 1549 this function may invalidate the previously returned string. If file is 1550 closed, then the string previously returned by gzerror will no longer be 1551 available. 1552 1553 gzerror() should be used to distinguish errors from end-of-file for those 1554 functions above that do not distinguish those cases in their return values. 1555 */ 1556 1557 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); 1558 /* 1559 Clears the error and end-of-file flags for file. This is analogous to the 1560 clearerr() function in stdio. This is useful for continuing to read a gzip 1561 file that is being written concurrently. 1562 */ 1563 1564 #endif /* !Z_SOLO */ 1565 1566 /* checksum functions */ 1567 1568 /* 1569 These functions are not related to compression but are exported 1570 anyway because they might be useful in applications using the compression 1571 library. 1572 */ 1573 1574 #ifndef __LIBCKERN_HAVE_ADLER32_DECL 1575 #define __LIBCKERN_HAVE_ADLER32_DECL 1576 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 1577 #endif 1578 /* 1579 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 1580 return the updated checksum. If buf is Z_NULL, this function returns the 1581 required initial value for the checksum. 1582 1583 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 1584 much faster. 1585 1586 Usage example: 1587 1588 uLong adler = adler32(0L, Z_NULL, 0); 1589 1590 while (read_buffer(buffer, length) != EOF) { 1591 adler = adler32(adler, buffer, length); 1592 } 1593 if (adler != original_adler) error(); 1594 */ 1595 1596 /* 1597 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, 1598 z_off_t len2)); 1599 1600 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 1601 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for 1602 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of 1603 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note 1604 that the z_off_t type (like off_t) is a signed integer. If len2 is 1605 negative, the result has no meaning or utility. 1606 */ 1607 1608 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); 1609 /* 1610 Update a running CRC-32 with the bytes buf[0..len-1] and return the 1611 updated CRC-32. If buf is Z_NULL, this function returns the required 1612 initial value for the crc. Pre- and post-conditioning (one's complement) is 1613 performed within this function so it shouldn't be done by the application. 1614 1615 Usage example: 1616 1617 uLong crc = crc32(0L, Z_NULL, 0); 1618 1619 while (read_buffer(buffer, length) != EOF) { 1620 crc = crc32(crc, buffer, length); 1621 } 1622 if (crc != original_crc) error(); 1623 */ 1624 1625 /* 1626 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); 1627 1628 Combine two CRC-32 check values into one. For two sequences of bytes, 1629 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were 1630 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 1631 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and 1632 len2. 1633 */ 1634 1635 1636 /* various hacks, don't look :) */ 1637 1638 /* deflateInit and inflateInit are macros to allow checking the zlib version 1639 * and the compiler's view of z_stream: 1640 */ 1641 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, 1642 const char *version, int stream_size)); 1643 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, 1644 const char *version, int stream_size)); 1645 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 1646 int windowBits, int memLevel, 1647 int strategy, const char *version, 1648 int stream_size)); 1649 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 1650 const char *version, int stream_size)); 1651 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, 1652 unsigned char FAR *window, 1653 const char *version, 1654 int stream_size)); 1655 #define deflateInit(strm, level) \ 1656 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) 1657 #define inflateInit(strm) \ 1658 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) 1659 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 1660 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ 1661 (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) 1662 #define inflateInit2(strm, windowBits) \ 1663 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ 1664 (int)sizeof(z_stream)) 1665 #define inflateBackInit(strm, windowBits, window) \ 1666 inflateBackInit_((strm), (windowBits), (window), \ 1667 ZLIB_VERSION, (int)sizeof(z_stream)) 1668 1669 #ifndef Z_SOLO 1670 1671 /* gzgetc() macro and its supporting function and exposed data structure. Note 1672 * that the real internal state is much larger than the exposed structure. 1673 * This abbreviated structure exposes just enough for the gzgetc() macro. The 1674 * user should not mess with these exposed elements, since their names or 1675 * behavior could change in the future, perhaps even capriciously. They can 1676 * only be used by the gzgetc() macro. You have been warned. 1677 */ 1678 struct gzFile_s { 1679 unsigned have; 1680 unsigned char *next; 1681 z_off64_t pos; 1682 }; 1683 ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ 1684 #ifdef Z_PREFIX_SET 1685 # undef z_gzgetc 1686 # define z_gzgetc(g) \ 1687 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) 1688 #else 1689 # define gzgetc(g) \ 1690 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) 1691 #endif 1692 1693 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or 1694 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if 1695 * both are true, the application gets the *64 functions, and the regular 1696 * functions are changed to 64 bits) -- in case these are set on systems 1697 * without large file support, _LFS64_LARGEFILE must also be true 1698 */ 1699 #ifdef Z_LARGE64 1700 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); 1701 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); 1702 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); 1703 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); 1704 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); 1705 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); 1706 #endif 1707 1708 #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) 1709 # ifdef Z_PREFIX_SET 1710 # define z_gzopen z_gzopen64 1711 # define z_gzseek z_gzseek64 1712 # define z_gztell z_gztell64 1713 # define z_gzoffset z_gzoffset64 1714 # define z_adler32_combine z_adler32_combine64 1715 # define z_crc32_combine z_crc32_combine64 1716 # else 1717 # define gzopen gzopen64 1718 # define gzseek gzseek64 1719 # define gztell gztell64 1720 # define gzoffset gzoffset64 1721 # define adler32_combine adler32_combine64 1722 # define crc32_combine crc32_combine64 1723 # endif 1724 # ifndef Z_LARGE64 1725 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); 1726 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); 1727 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); 1728 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); 1729 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); 1730 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); 1731 # endif 1732 #else 1733 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); 1734 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); 1735 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); 1736 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); 1737 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); 1738 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); 1739 #endif 1740 1741 #else /* Z_SOLO */ 1742 1743 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); 1744 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); 1745 1746 #endif /* !Z_SOLO */ 1747 1748 /* hack for buggy compilers */ 1749 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) 1750 struct internal_state {int dummy;}; 1751 #endif 1752 1753 /* undocumented functions */ 1754 ZEXTERN const char * ZEXPORT zError OF((int)); 1755 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); 1756 ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void)); 1757 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); 1758 ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp)); 1759 ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp)); 1760 #if defined(_WIN32) && !defined(Z_SOLO) 1761 ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path, 1762 const char *mode)); 1763 #endif 1764 #ifndef ZLIB_FREESTANDING /* -fhosted, i.e. userland implementation */ 1765 #if defined(STDC) || defined(Z_HAVE_STDARG_H) 1766 # ifndef Z_SOLO 1767 ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file, 1768 const char *format, 1769 va_list va)) 1770 __attribute__((__format__(__printf__, 2, 0))); 1771 # endif 1772 #endif 1773 #endif 1774 1775 #ifdef __cplusplus 1776 } 1777 #endif 1778 1779 #ifndef ZLIB_FREESTANDING /* -fhosted, i.e. userland implementation */ 1780 /* MirOS extension: gzfopen.c */ 1781 #define ZLIB_HAS_GZFOPEN 1782 1783 #include <stdio.h> 1784 __BEGIN_DECLS 1785 FILE *gzfopen(const char *, const char *); 1786 FILE *gzfdopen(int, const char *); 1787 __END_DECLS 1788 #endif /* !ZLIB_FREESTANDING */ 1789 1790 #ifndef _STANDALONE /* kernel or userland, but not bootloader */ 1791 /* MirOS extension: adler32() and crc32() entropy hack */ 1792 #define ZLIB_HAS_ADLERPUSH 1793 #define ZLIB_HAS_CRC32PUSH 1794 #endif 1795 1796 #endif /* ZLIB_H */ 1797