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comparison mupdf-source/thirdparty/zlib/zlib.h @ 2:b50eed0cc0ef upstream
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| author | Franz Glasner <fzglas.hg@dom66.de> |
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| date | Mon, 15 Sep 2025 11:43:07 +0200 |
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| 1:1d09e1dec1d9 | 2:b50eed0cc0ef |
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| 1 /* zlib.h -- interface of the 'zlib' general purpose compression library | |
| 2 version 1.3.1, January 22nd, 2024 | |
| 3 | |
| 4 Copyright (C) 1995-2024 Jean-loup Gailly and Mark Adler | |
| 5 | |
| 6 This software is provided 'as-is', without any express or implied | |
| 7 warranty. In no event will the authors be held liable for any damages | |
| 8 arising from the use of this software. | |
| 9 | |
| 10 Permission is granted to anyone to use this software for any purpose, | |
| 11 including commercial applications, and to alter it and redistribute it | |
| 12 freely, subject to the following restrictions: | |
| 13 | |
| 14 1. The origin of this software must not be misrepresented; you must not | |
| 15 claim that you wrote the original software. If you use this software | |
| 16 in a product, an acknowledgment in the product documentation would be | |
| 17 appreciated but is not required. | |
| 18 2. Altered source versions must be plainly marked as such, and must not be | |
| 19 misrepresented as being the original software. | |
| 20 3. This notice may not be removed or altered from any source distribution. | |
| 21 | |
| 22 Jean-loup Gailly Mark Adler | |
| 23 jloup@gzip.org madler@alumni.caltech.edu | |
| 24 | |
| 25 | |
| 26 The data format used by the zlib library is described by RFCs (Request for | |
| 27 Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950 | |
| 28 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). | |
| 29 */ | |
| 30 | |
| 31 #ifndef ZLIB_H | |
| 32 #define ZLIB_H | |
| 33 | |
| 34 #include "zconf.h" | |
| 35 | |
| 36 #ifdef __cplusplus | |
| 37 extern "C" { | |
| 38 #endif | |
| 39 | |
| 40 #define ZLIB_VERSION "1.3.1" | |
| 41 #define ZLIB_VERNUM 0x1310 | |
| 42 #define ZLIB_VER_MAJOR 1 | |
| 43 #define ZLIB_VER_MINOR 3 | |
| 44 #define ZLIB_VER_REVISION 1 | |
| 45 #define ZLIB_VER_SUBREVISION 0 | |
| 46 | |
| 47 /* | |
| 48 The 'zlib' compression library provides in-memory compression and | |
| 49 decompression functions, including integrity checks of the uncompressed data. | |
| 50 This version of the library supports only one compression method (deflation) | |
| 51 but other algorithms will be added later and will have the same stream | |
| 52 interface. | |
| 53 | |
| 54 Compression can be done in a single step if the buffers are large enough, | |
| 55 or can be done by repeated calls of the compression function. In the latter | |
| 56 case, the application must provide more input and/or consume the output | |
| 57 (providing more output space) before each call. | |
| 58 | |
| 59 The compressed data format used by default by the in-memory functions is | |
| 60 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped | |
| 61 around a deflate stream, which is itself documented in RFC 1951. | |
| 62 | |
| 63 The library also supports reading and writing files in gzip (.gz) format | |
| 64 with an interface similar to that of stdio using the functions that start | |
| 65 with "gz". The gzip format is different from the zlib format. gzip is a | |
| 66 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. | |
| 67 | |
| 68 This library can optionally read and write gzip and raw deflate streams in | |
| 69 memory as well. | |
| 70 | |
| 71 The zlib format was designed to be compact and fast for use in memory | |
| 72 and on communications channels. The gzip format was designed for single- | |
| 73 file compression on file systems, has a larger header than zlib to maintain | |
| 74 directory information, and uses a different, slower check method than zlib. | |
| 75 | |
| 76 The library does not install any signal handler. The decoder checks | |
| 77 the consistency of the compressed data, so the library should never crash | |
| 78 even in the case of corrupted input. | |
| 79 */ | |
| 80 | |
| 81 typedef voidpf (*alloc_func)(voidpf opaque, uInt items, uInt size); | |
| 82 typedef void (*free_func)(voidpf opaque, voidpf address); | |
| 83 | |
| 84 struct internal_state; | |
| 85 | |
| 86 typedef struct z_stream_s { | |
| 87 z_const Bytef *next_in; /* next input byte */ | |
| 88 uInt avail_in; /* number of bytes available at next_in */ | |
| 89 uLong total_in; /* total number of input bytes read so far */ | |
| 90 | |
| 91 Bytef *next_out; /* next output byte will go here */ | |
| 92 uInt avail_out; /* remaining free space at next_out */ | |
| 93 uLong total_out; /* total number of bytes output so far */ | |
| 94 | |
| 95 z_const char *msg; /* last error message, NULL if no error */ | |
| 96 struct internal_state FAR *state; /* not visible by applications */ | |
| 97 | |
| 98 alloc_func zalloc; /* used to allocate the internal state */ | |
| 99 free_func zfree; /* used to free the internal state */ | |
| 100 voidpf opaque; /* private data object passed to zalloc and zfree */ | |
| 101 | |
| 102 int data_type; /* best guess about the data type: binary or text | |
| 103 for deflate, or the decoding state for inflate */ | |
| 104 uLong adler; /* Adler-32 or CRC-32 value of the uncompressed data */ | |
| 105 uLong reserved; /* reserved for future use */ | |
| 106 } z_stream; | |
| 107 | |
| 108 typedef z_stream FAR *z_streamp; | |
| 109 | |
| 110 /* | |
| 111 gzip header information passed to and from zlib routines. See RFC 1952 | |
| 112 for more details on the meanings of these fields. | |
| 113 */ | |
| 114 typedef struct gz_header_s { | |
| 115 int text; /* true if compressed data believed to be text */ | |
| 116 uLong time; /* modification time */ | |
| 117 int xflags; /* extra flags (not used when writing a gzip file) */ | |
| 118 int os; /* operating system */ | |
| 119 Bytef *extra; /* pointer to extra field or Z_NULL if none */ | |
| 120 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ | |
| 121 uInt extra_max; /* space at extra (only when reading header) */ | |
| 122 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ | |
| 123 uInt name_max; /* space at name (only when reading header) */ | |
| 124 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ | |
| 125 uInt comm_max; /* space at comment (only when reading header) */ | |
| 126 int hcrc; /* true if there was or will be a header crc */ | |
| 127 int done; /* true when done reading gzip header (not used | |
| 128 when writing a gzip file) */ | |
| 129 } gz_header; | |
| 130 | |
| 131 typedef gz_header FAR *gz_headerp; | |
| 132 | |
| 133 /* | |
| 134 The application must update next_in and avail_in when avail_in has dropped | |
| 135 to zero. It must update next_out and avail_out when avail_out has dropped | |
| 136 to zero. The application must initialize zalloc, zfree and opaque before | |
| 137 calling the init function. All other fields are set by the compression | |
| 138 library and must not be updated by the application. | |
| 139 | |
| 140 The opaque value provided by the application will be passed as the first | |
| 141 parameter for calls of zalloc and zfree. This can be useful for custom | |
| 142 memory management. The compression library attaches no meaning to the | |
| 143 opaque value. | |
| 144 | |
| 145 zalloc must return Z_NULL if there is not enough memory for the object. | |
| 146 If zlib is used in a multi-threaded application, zalloc and zfree must be | |
| 147 thread safe. In that case, zlib is thread-safe. When zalloc and zfree are | |
| 148 Z_NULL on entry to the initialization function, they are set to internal | |
| 149 routines that use the standard library functions malloc() and free(). | |
| 150 | |
| 151 On 16-bit systems, the functions zalloc and zfree must be able to allocate | |
| 152 exactly 65536 bytes, but will not be required to allocate more than this if | |
| 153 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers | |
| 154 returned by zalloc for objects of exactly 65536 bytes *must* have their | |
| 155 offset normalized to zero. The default allocation function provided by this | |
| 156 library ensures this (see zutil.c). To reduce memory requirements and avoid | |
| 157 any allocation of 64K objects, at the expense of compression ratio, compile | |
| 158 the library with -DMAX_WBITS=14 (see zconf.h). | |
| 159 | |
| 160 The fields total_in and total_out can be used for statistics or progress | |
| 161 reports. After compression, total_in holds the total size of the | |
| 162 uncompressed data and may be saved for use by the decompressor (particularly | |
| 163 if the decompressor wants to decompress everything in a single step). | |
| 164 */ | |
| 165 | |
| 166 /* constants */ | |
| 167 | |
| 168 #define Z_NO_FLUSH 0 | |
| 169 #define Z_PARTIAL_FLUSH 1 | |
| 170 #define Z_SYNC_FLUSH 2 | |
| 171 #define Z_FULL_FLUSH 3 | |
| 172 #define Z_FINISH 4 | |
| 173 #define Z_BLOCK 5 | |
| 174 #define Z_TREES 6 | |
| 175 /* Allowed flush values; see deflate() and inflate() below for details */ | |
| 176 | |
| 177 #define Z_OK 0 | |
| 178 #define Z_STREAM_END 1 | |
| 179 #define Z_NEED_DICT 2 | |
| 180 #define Z_ERRNO (-1) | |
| 181 #define Z_STREAM_ERROR (-2) | |
| 182 #define Z_DATA_ERROR (-3) | |
| 183 #define Z_MEM_ERROR (-4) | |
| 184 #define Z_BUF_ERROR (-5) | |
| 185 #define Z_VERSION_ERROR (-6) | |
| 186 /* Return codes for the compression/decompression functions. Negative values | |
| 187 * are errors, positive values are used for special but normal events. | |
| 188 */ | |
| 189 | |
| 190 #define Z_NO_COMPRESSION 0 | |
| 191 #define Z_BEST_SPEED 1 | |
| 192 #define Z_BEST_COMPRESSION 9 | |
| 193 #define Z_DEFAULT_COMPRESSION (-1) | |
| 194 /* compression levels */ | |
| 195 | |
| 196 #define Z_FILTERED 1 | |
| 197 #define Z_HUFFMAN_ONLY 2 | |
| 198 #define Z_RLE 3 | |
| 199 #define Z_FIXED 4 | |
| 200 #define Z_DEFAULT_STRATEGY 0 | |
| 201 /* compression strategy; see deflateInit2() below for details */ | |
| 202 | |
| 203 #define Z_BINARY 0 | |
| 204 #define Z_TEXT 1 | |
| 205 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ | |
| 206 #define Z_UNKNOWN 2 | |
| 207 /* Possible values of the data_type field for deflate() */ | |
| 208 | |
| 209 #define Z_DEFLATED 8 | |
| 210 /* The deflate compression method (the only one supported in this version) */ | |
| 211 | |
| 212 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ | |
| 213 | |
| 214 #define zlib_version zlibVersion() | |
| 215 /* for compatibility with versions < 1.0.2 */ | |
| 216 | |
| 217 | |
| 218 /* basic functions */ | |
| 219 | |
| 220 ZEXTERN const char * ZEXPORT zlibVersion(void); | |
| 221 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. | |
| 222 If the first character differs, the library code actually used is not | |
| 223 compatible with the zlib.h header file used by the application. This check | |
| 224 is automatically made by deflateInit and inflateInit. | |
| 225 */ | |
| 226 | |
| 227 /* | |
| 228 ZEXTERN int ZEXPORT deflateInit(z_streamp strm, int level); | |
| 229 | |
| 230 Initializes the internal stream state for compression. The fields | |
| 231 zalloc, zfree and opaque must be initialized before by the caller. If | |
| 232 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default | |
| 233 allocation functions. total_in, total_out, adler, and msg are initialized. | |
| 234 | |
| 235 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: | |
| 236 1 gives best speed, 9 gives best compression, 0 gives no compression at all | |
| 237 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION | |
| 238 requests a default compromise between speed and compression (currently | |
| 239 equivalent to level 6). | |
| 240 | |
| 241 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
| 242 memory, Z_STREAM_ERROR if level is not a valid compression level, or | |
| 243 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible | |
| 244 with the version assumed by the caller (ZLIB_VERSION). msg is set to null | |
| 245 if there is no error message. deflateInit does not perform any compression: | |
| 246 this will be done by deflate(). | |
| 247 */ | |
| 248 | |
| 249 | |
| 250 ZEXTERN int ZEXPORT deflate(z_streamp strm, int flush); | |
| 251 /* | |
| 252 deflate compresses as much data as possible, and stops when the input | |
| 253 buffer becomes empty or the output buffer becomes full. It may introduce | |
| 254 some output latency (reading input without producing any output) except when | |
| 255 forced to flush. | |
| 256 | |
| 257 The detailed semantics are as follows. deflate performs one or both of the | |
| 258 following actions: | |
| 259 | |
| 260 - Compress more input starting at next_in and update next_in and avail_in | |
| 261 accordingly. If not all input can be processed (because there is not | |
| 262 enough room in the output buffer), next_in and avail_in are updated and | |
| 263 processing will resume at this point for the next call of deflate(). | |
| 264 | |
| 265 - Generate more output starting at next_out and update next_out and avail_out | |
| 266 accordingly. This action is forced if the parameter flush is non zero. | |
| 267 Forcing flush frequently degrades the compression ratio, so this parameter | |
| 268 should be set only when necessary. Some output may be provided even if | |
| 269 flush is zero. | |
| 270 | |
| 271 Before the call of deflate(), the application should ensure that at least | |
| 272 one of the actions is possible, by providing more input and/or consuming more | |
| 273 output, and updating avail_in or avail_out accordingly; avail_out should | |
| 274 never be zero before the call. The application can consume the compressed | |
| 275 output when it wants, for example when the output buffer is full (avail_out | |
| 276 == 0), or after each call of deflate(). If deflate returns Z_OK and with | |
| 277 zero avail_out, it must be called again after making room in the output | |
| 278 buffer because there might be more output pending. See deflatePending(), | |
| 279 which can be used if desired to determine whether or not there is more output | |
| 280 in that case. | |
| 281 | |
| 282 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to | |
| 283 decide how much data to accumulate before producing output, in order to | |
| 284 maximize compression. | |
| 285 | |
| 286 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is | |
| 287 flushed to the output buffer and the output is aligned on a byte boundary, so | |
| 288 that the decompressor can get all input data available so far. (In | |
| 289 particular avail_in is zero after the call if enough output space has been | |
| 290 provided before the call.) Flushing may degrade compression for some | |
| 291 compression algorithms and so it should be used only when necessary. This | |
| 292 completes the current deflate block and follows it with an empty stored block | |
| 293 that is three bits plus filler bits to the next byte, followed by four bytes | |
| 294 (00 00 ff ff). | |
| 295 | |
| 296 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the | |
| 297 output buffer, but the output is not aligned to a byte boundary. All of the | |
| 298 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. | |
| 299 This completes the current deflate block and follows it with an empty fixed | |
| 300 codes block that is 10 bits long. This assures that enough bytes are output | |
| 301 in order for the decompressor to finish the block before the empty fixed | |
| 302 codes block. | |
| 303 | |
| 304 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as | |
| 305 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to | |
| 306 seven bits of the current block are held to be written as the next byte after | |
| 307 the next deflate block is completed. In this case, the decompressor may not | |
| 308 be provided enough bits at this point in order to complete decompression of | |
| 309 the data provided so far to the compressor. It may need to wait for the next | |
| 310 block to be emitted. This is for advanced applications that need to control | |
| 311 the emission of deflate blocks. | |
| 312 | |
| 313 If flush is set to Z_FULL_FLUSH, all output is flushed as with | |
| 314 Z_SYNC_FLUSH, and the compression state is reset so that decompression can | |
| 315 restart from this point if previous compressed data has been damaged or if | |
| 316 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade | |
| 317 compression. | |
| 318 | |
| 319 If deflate returns with avail_out == 0, this function must be called again | |
| 320 with the same value of the flush parameter and more output space (updated | |
| 321 avail_out), until the flush is complete (deflate returns with non-zero | |
| 322 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that | |
| 323 avail_out is greater than six when the flush marker begins, in order to avoid | |
| 324 repeated flush markers upon calling deflate() again when avail_out == 0. | |
| 325 | |
| 326 If the parameter flush is set to Z_FINISH, pending input is processed, | |
| 327 pending output is flushed and deflate returns with Z_STREAM_END if there was | |
| 328 enough output space. If deflate returns with Z_OK or Z_BUF_ERROR, this | |
| 329 function must be called again with Z_FINISH and more output space (updated | |
| 330 avail_out) but no more input data, until it returns with Z_STREAM_END or an | |
| 331 error. After deflate has returned Z_STREAM_END, the only possible operations | |
| 332 on the stream are deflateReset or deflateEnd. | |
| 333 | |
| 334 Z_FINISH can be used in the first deflate call after deflateInit if all the | |
| 335 compression is to be done in a single step. In order to complete in one | |
| 336 call, avail_out must be at least the value returned by deflateBound (see | |
| 337 below). Then deflate is guaranteed to return Z_STREAM_END. If not enough | |
| 338 output space is provided, deflate will not return Z_STREAM_END, and it must | |
| 339 be called again as described above. | |
| 340 | |
| 341 deflate() sets strm->adler to the Adler-32 checksum of all input read | |
| 342 so far (that is, total_in bytes). If a gzip stream is being generated, then | |
| 343 strm->adler will be the CRC-32 checksum of the input read so far. (See | |
| 344 deflateInit2 below.) | |
| 345 | |
| 346 deflate() may update strm->data_type if it can make a good guess about | |
| 347 the input data type (Z_BINARY or Z_TEXT). If in doubt, the data is | |
| 348 considered binary. This field is only for information purposes and does not | |
| 349 affect the compression algorithm in any manner. | |
| 350 | |
| 351 deflate() returns Z_OK if some progress has been made (more input | |
| 352 processed or more output produced), Z_STREAM_END if all input has been | |
| 353 consumed and all output has been produced (only when flush is set to | |
| 354 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example | |
| 355 if next_in or next_out was Z_NULL or the state was inadvertently written over | |
| 356 by the application), or Z_BUF_ERROR if no progress is possible (for example | |
| 357 avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and | |
| 358 deflate() can be called again with more input and more output space to | |
| 359 continue compressing. | |
| 360 */ | |
| 361 | |
| 362 | |
| 363 ZEXTERN int ZEXPORT deflateEnd(z_streamp strm); | |
| 364 /* | |
| 365 All dynamically allocated data structures for this stream are freed. | |
| 366 This function discards any unprocessed input and does not flush any pending | |
| 367 output. | |
| 368 | |
| 369 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the | |
| 370 stream state was inconsistent, Z_DATA_ERROR if the stream was freed | |
| 371 prematurely (some input or output was discarded). In the error case, msg | |
| 372 may be set but then points to a static string (which must not be | |
| 373 deallocated). | |
| 374 */ | |
| 375 | |
| 376 | |
| 377 /* | |
| 378 ZEXTERN int ZEXPORT inflateInit(z_streamp strm); | |
| 379 | |
| 380 Initializes the internal stream state for decompression. The fields | |
| 381 next_in, avail_in, zalloc, zfree and opaque must be initialized before by | |
| 382 the caller. In the current version of inflate, the provided input is not | |
| 383 read or consumed. The allocation of a sliding window will be deferred to | |
| 384 the first call of inflate (if the decompression does not complete on the | |
| 385 first call). If zalloc and zfree are set to Z_NULL, inflateInit updates | |
| 386 them to use default allocation functions. total_in, total_out, adler, and | |
| 387 msg are initialized. | |
| 388 | |
| 389 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
| 390 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the | |
| 391 version assumed by the caller, or Z_STREAM_ERROR if the parameters are | |
| 392 invalid, such as a null pointer to the structure. msg is set to null if | |
| 393 there is no error message. inflateInit does not perform any decompression. | |
| 394 Actual decompression will be done by inflate(). So next_in, and avail_in, | |
| 395 next_out, and avail_out are unused and unchanged. The current | |
| 396 implementation of inflateInit() does not process any header information -- | |
| 397 that is deferred until inflate() is called. | |
| 398 */ | |
| 399 | |
| 400 | |
| 401 ZEXTERN int ZEXPORT inflate(z_streamp strm, int flush); | |
| 402 /* | |
| 403 inflate decompresses as much data as possible, and stops when the input | |
| 404 buffer becomes empty or the output buffer becomes full. It may introduce | |
| 405 some output latency (reading input without producing any output) except when | |
| 406 forced to flush. | |
| 407 | |
| 408 The detailed semantics are as follows. inflate performs one or both of the | |
| 409 following actions: | |
| 410 | |
| 411 - Decompress more input starting at next_in and update next_in and avail_in | |
| 412 accordingly. If not all input can be processed (because there is not | |
| 413 enough room in the output buffer), then next_in and avail_in are updated | |
| 414 accordingly, and processing will resume at this point for the next call of | |
| 415 inflate(). | |
| 416 | |
| 417 - Generate more output starting at next_out and update next_out and avail_out | |
| 418 accordingly. inflate() provides as much output as possible, until there is | |
| 419 no more input data or no more space in the output buffer (see below about | |
| 420 the flush parameter). | |
| 421 | |
| 422 Before the call of inflate(), the application should ensure that at least | |
| 423 one of the actions is possible, by providing more input and/or consuming more | |
| 424 output, and updating the next_* and avail_* values accordingly. If the | |
| 425 caller of inflate() does not provide both available input and available | |
| 426 output space, it is possible that there will be no progress made. The | |
| 427 application can consume the uncompressed output when it wants, for example | |
| 428 when the output buffer is full (avail_out == 0), or after each call of | |
| 429 inflate(). If inflate returns Z_OK and with zero avail_out, it must be | |
| 430 called again after making room in the output buffer because there might be | |
| 431 more output pending. | |
| 432 | |
| 433 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, | |
| 434 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much | |
| 435 output as possible to the output buffer. Z_BLOCK requests that inflate() | |
| 436 stop if and when it gets to the next deflate block boundary. When decoding | |
| 437 the zlib or gzip format, this will cause inflate() to return immediately | |
| 438 after the header and before the first block. When doing a raw inflate, | |
| 439 inflate() will go ahead and process the first block, and will return when it | |
| 440 gets to the end of that block, or when it runs out of data. | |
| 441 | |
| 442 The Z_BLOCK option assists in appending to or combining deflate streams. | |
| 443 To assist in this, on return inflate() always sets strm->data_type to the | |
| 444 number of unused bits in the last byte taken from strm->next_in, plus 64 if | |
| 445 inflate() is currently decoding the last block in the deflate stream, plus | |
| 446 128 if inflate() returned immediately after decoding an end-of-block code or | |
| 447 decoding the complete header up to just before the first byte of the deflate | |
| 448 stream. The end-of-block will not be indicated until all of the uncompressed | |
| 449 data from that block has been written to strm->next_out. The number of | |
| 450 unused bits may in general be greater than seven, except when bit 7 of | |
| 451 data_type is set, in which case the number of unused bits will be less than | |
| 452 eight. data_type is set as noted here every time inflate() returns for all | |
| 453 flush options, and so can be used to determine the amount of currently | |
| 454 consumed input in bits. | |
| 455 | |
| 456 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the | |
| 457 end of each deflate block header is reached, before any actual data in that | |
| 458 block is decoded. This allows the caller to determine the length of the | |
| 459 deflate block header for later use in random access within a deflate block. | |
| 460 256 is added to the value of strm->data_type when inflate() returns | |
| 461 immediately after reaching the end of the deflate block header. | |
| 462 | |
| 463 inflate() should normally be called until it returns Z_STREAM_END or an | |
| 464 error. However if all decompression is to be performed in a single step (a | |
| 465 single call of inflate), the parameter flush should be set to Z_FINISH. In | |
| 466 this case all pending input is processed and all pending output is flushed; | |
| 467 avail_out must be large enough to hold all of the uncompressed data for the | |
| 468 operation to complete. (The size of the uncompressed data may have been | |
| 469 saved by the compressor for this purpose.) The use of Z_FINISH is not | |
| 470 required to perform an inflation in one step. However it may be used to | |
| 471 inform inflate that a faster approach can be used for the single inflate() | |
| 472 call. Z_FINISH also informs inflate to not maintain a sliding window if the | |
| 473 stream completes, which reduces inflate's memory footprint. If the stream | |
| 474 does not complete, either because not all of the stream is provided or not | |
| 475 enough output space is provided, then a sliding window will be allocated and | |
| 476 inflate() can be called again to continue the operation as if Z_NO_FLUSH had | |
| 477 been used. | |
| 478 | |
| 479 In this implementation, inflate() always flushes as much output as | |
| 480 possible to the output buffer, and always uses the faster approach on the | |
| 481 first call. So the effects of the flush parameter in this implementation are | |
| 482 on the return value of inflate() as noted below, when inflate() returns early | |
| 483 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of | |
| 484 memory for a sliding window when Z_FINISH is used. | |
| 485 | |
| 486 If a preset dictionary is needed after this call (see inflateSetDictionary | |
| 487 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary | |
| 488 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets | |
| 489 strm->adler to the Adler-32 checksum of all output produced so far (that is, | |
| 490 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described | |
| 491 below. At the end of the stream, inflate() checks that its computed Adler-32 | |
| 492 checksum is equal to that saved by the compressor and returns Z_STREAM_END | |
| 493 only if the checksum is correct. | |
| 494 | |
| 495 inflate() can decompress and check either zlib-wrapped or gzip-wrapped | |
| 496 deflate data. The header type is detected automatically, if requested when | |
| 497 initializing with inflateInit2(). Any information contained in the gzip | |
| 498 header is not retained unless inflateGetHeader() is used. When processing | |
| 499 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output | |
| 500 produced so far. The CRC-32 is checked against the gzip trailer, as is the | |
| 501 uncompressed length, modulo 2^32. | |
| 502 | |
| 503 inflate() returns Z_OK if some progress has been made (more input processed | |
| 504 or more output produced), Z_STREAM_END if the end of the compressed data has | |
| 505 been reached and all uncompressed output has been produced, Z_NEED_DICT if a | |
| 506 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was | |
| 507 corrupted (input stream not conforming to the zlib format or incorrect check | |
| 508 value, in which case strm->msg points to a string with a more specific | |
| 509 error), Z_STREAM_ERROR if the stream structure was inconsistent (for example | |
| 510 next_in or next_out was Z_NULL, or the state was inadvertently written over | |
| 511 by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR | |
| 512 if no progress was possible or if there was not enough room in the output | |
| 513 buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and | |
| 514 inflate() can be called again with more input and more output space to | |
| 515 continue decompressing. If Z_DATA_ERROR is returned, the application may | |
| 516 then call inflateSync() to look for a good compression block if a partial | |
| 517 recovery of the data is to be attempted. | |
| 518 */ | |
| 519 | |
| 520 | |
| 521 ZEXTERN int ZEXPORT inflateEnd(z_streamp strm); | |
| 522 /* | |
| 523 All dynamically allocated data structures for this stream are freed. | |
| 524 This function discards any unprocessed input and does not flush any pending | |
| 525 output. | |
| 526 | |
| 527 inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state | |
| 528 was inconsistent. | |
| 529 */ | |
| 530 | |
| 531 | |
| 532 /* Advanced functions */ | |
| 533 | |
| 534 /* | |
| 535 The following functions are needed only in some special applications. | |
| 536 */ | |
| 537 | |
| 538 /* | |
| 539 ZEXTERN int ZEXPORT deflateInit2(z_streamp strm, | |
| 540 int level, | |
| 541 int method, | |
| 542 int windowBits, | |
| 543 int memLevel, | |
| 544 int strategy); | |
| 545 | |
| 546 This is another version of deflateInit with more compression options. The | |
| 547 fields zalloc, zfree and opaque must be initialized before by the caller. | |
| 548 | |
| 549 The method parameter is the compression method. It must be Z_DEFLATED in | |
| 550 this version of the library. | |
| 551 | |
| 552 The windowBits parameter is the base two logarithm of the window size | |
| 553 (the size of the history buffer). It should be in the range 8..15 for this | |
| 554 version of the library. Larger values of this parameter result in better | |
| 555 compression at the expense of memory usage. The default value is 15 if | |
| 556 deflateInit is used instead. | |
| 557 | |
| 558 For the current implementation of deflate(), a windowBits value of 8 (a | |
| 559 window size of 256 bytes) is not supported. As a result, a request for 8 | |
| 560 will result in 9 (a 512-byte window). In that case, providing 8 to | |
| 561 inflateInit2() will result in an error when the zlib header with 9 is | |
| 562 checked against the initialization of inflate(). The remedy is to not use 8 | |
| 563 with deflateInit2() with this initialization, or at least in that case use 9 | |
| 564 with inflateInit2(). | |
| 565 | |
| 566 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits | |
| 567 determines the window size. deflate() will then generate raw deflate data | |
| 568 with no zlib header or trailer, and will not compute a check value. | |
| 569 | |
| 570 windowBits can also be greater than 15 for optional gzip encoding. Add | |
| 571 16 to windowBits to write a simple gzip header and trailer around the | |
| 572 compressed data instead of a zlib wrapper. The gzip header will have no | |
| 573 file name, no extra data, no comment, no modification time (set to zero), no | |
| 574 header crc, and the operating system will be set to the appropriate value, | |
| 575 if the operating system was determined at compile time. If a gzip stream is | |
| 576 being written, strm->adler is a CRC-32 instead of an Adler-32. | |
| 577 | |
| 578 For raw deflate or gzip encoding, a request for a 256-byte window is | |
| 579 rejected as invalid, since only the zlib header provides a means of | |
| 580 transmitting the window size to the decompressor. | |
| 581 | |
| 582 The memLevel parameter specifies how much memory should be allocated | |
| 583 for the internal compression state. memLevel=1 uses minimum memory but is | |
| 584 slow and reduces compression ratio; memLevel=9 uses maximum memory for | |
| 585 optimal speed. The default value is 8. See zconf.h for total memory usage | |
| 586 as a function of windowBits and memLevel. | |
| 587 | |
| 588 The strategy parameter is used to tune the compression algorithm. Use the | |
| 589 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a | |
| 590 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no | |
| 591 string match), or Z_RLE to limit match distances to one (run-length | |
| 592 encoding). Filtered data consists mostly of small values with a somewhat | |
| 593 random distribution. In this case, the compression algorithm is tuned to | |
| 594 compress them better. The effect of Z_FILTERED is to force more Huffman | |
| 595 coding and less string matching; it is somewhat intermediate between | |
| 596 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as | |
| 597 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The | |
| 598 strategy parameter only affects the compression ratio but not the | |
| 599 correctness of the compressed output even if it is not set appropriately. | |
| 600 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler | |
| 601 decoder for special applications. | |
| 602 | |
| 603 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
| 604 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid | |
| 605 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is | |
| 606 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is | |
| 607 set to null if there is no error message. deflateInit2 does not perform any | |
| 608 compression: this will be done by deflate(). | |
| 609 */ | |
| 610 | |
| 611 ZEXTERN int ZEXPORT deflateSetDictionary(z_streamp strm, | |
| 612 const Bytef *dictionary, | |
| 613 uInt dictLength); | |
| 614 /* | |
| 615 Initializes the compression dictionary from the given byte sequence | |
| 616 without producing any compressed output. When using the zlib format, this | |
| 617 function must be called immediately after deflateInit, deflateInit2 or | |
| 618 deflateReset, and before any call of deflate. When doing raw deflate, this | |
| 619 function must be called either before any call of deflate, or immediately | |
| 620 after the completion of a deflate block, i.e. after all input has been | |
| 621 consumed and all output has been delivered when using any of the flush | |
| 622 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The | |
| 623 compressor and decompressor must use exactly the same dictionary (see | |
| 624 inflateSetDictionary). | |
| 625 | |
| 626 The dictionary should consist of strings (byte sequences) that are likely | |
| 627 to be encountered later in the data to be compressed, with the most commonly | |
| 628 used strings preferably put towards the end of the dictionary. Using a | |
| 629 dictionary is most useful when the data to be compressed is short and can be | |
| 630 predicted with good accuracy; the data can then be compressed better than | |
| 631 with the default empty dictionary. | |
| 632 | |
| 633 Depending on the size of the compression data structures selected by | |
| 634 deflateInit or deflateInit2, a part of the dictionary may in effect be | |
| 635 discarded, for example if the dictionary is larger than the window size | |
| 636 provided in deflateInit or deflateInit2. Thus the strings most likely to be | |
| 637 useful should be put at the end of the dictionary, not at the front. In | |
| 638 addition, the current implementation of deflate will use at most the window | |
| 639 size minus 262 bytes of the provided dictionary. | |
| 640 | |
| 641 Upon return of this function, strm->adler is set to the Adler-32 value | |
| 642 of the dictionary; the decompressor may later use this value to determine | |
| 643 which dictionary has been used by the compressor. (The Adler-32 value | |
| 644 applies to the whole dictionary even if only a subset of the dictionary is | |
| 645 actually used by the compressor.) If a raw deflate was requested, then the | |
| 646 Adler-32 value is not computed and strm->adler is not set. | |
| 647 | |
| 648 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a | |
| 649 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is | |
| 650 inconsistent (for example if deflate has already been called for this stream | |
| 651 or if not at a block boundary for raw deflate). deflateSetDictionary does | |
| 652 not perform any compression: this will be done by deflate(). | |
| 653 */ | |
| 654 | |
| 655 ZEXTERN int ZEXPORT deflateGetDictionary(z_streamp strm, | |
| 656 Bytef *dictionary, | |
| 657 uInt *dictLength); | |
| 658 /* | |
| 659 Returns the sliding dictionary being maintained by deflate. dictLength is | |
| 660 set to the number of bytes in the dictionary, and that many bytes are copied | |
| 661 to dictionary. dictionary must have enough space, where 32768 bytes is | |
| 662 always enough. If deflateGetDictionary() is called with dictionary equal to | |
| 663 Z_NULL, then only the dictionary length is returned, and nothing is copied. | |
| 664 Similarly, if dictLength is Z_NULL, then it is not set. | |
| 665 | |
| 666 deflateGetDictionary() may return a length less than the window size, even | |
| 667 when more than the window size in input has been provided. It may return up | |
| 668 to 258 bytes less in that case, due to how zlib's implementation of deflate | |
| 669 manages the sliding window and lookahead for matches, where matches can be | |
| 670 up to 258 bytes long. If the application needs the last window-size bytes of | |
| 671 input, then that would need to be saved by the application outside of zlib. | |
| 672 | |
| 673 deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the | |
| 674 stream state is inconsistent. | |
| 675 */ | |
| 676 | |
| 677 ZEXTERN int ZEXPORT deflateCopy(z_streamp dest, | |
| 678 z_streamp source); | |
| 679 /* | |
| 680 Sets the destination stream as a complete copy of the source stream. | |
| 681 | |
| 682 This function can be useful when several compression strategies will be | |
| 683 tried, for example when there are several ways of pre-processing the input | |
| 684 data with a filter. The streams that will be discarded should then be freed | |
| 685 by calling deflateEnd. Note that deflateCopy duplicates the internal | |
| 686 compression state which can be quite large, so this strategy is slow and can | |
| 687 consume lots of memory. | |
| 688 | |
| 689 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | |
| 690 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | |
| 691 (such as zalloc being Z_NULL). msg is left unchanged in both source and | |
| 692 destination. | |
| 693 */ | |
| 694 | |
| 695 ZEXTERN int ZEXPORT deflateReset(z_streamp strm); | |
| 696 /* | |
| 697 This function is equivalent to deflateEnd followed by deflateInit, but | |
| 698 does not free and reallocate the internal compression state. The stream | |
| 699 will leave the compression level and any other attributes that may have been | |
| 700 set unchanged. total_in, total_out, adler, and msg are initialized. | |
| 701 | |
| 702 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | |
| 703 stream state was inconsistent (such as zalloc or state being Z_NULL). | |
| 704 */ | |
| 705 | |
| 706 ZEXTERN int ZEXPORT deflateParams(z_streamp strm, | |
| 707 int level, | |
| 708 int strategy); | |
| 709 /* | |
| 710 Dynamically update the compression level and compression strategy. The | |
| 711 interpretation of level and strategy is as in deflateInit2(). This can be | |
| 712 used to switch between compression and straight copy of the input data, or | |
| 713 to switch to a different kind of input data requiring a different strategy. | |
| 714 If the compression approach (which is a function of the level) or the | |
| 715 strategy is changed, and if there have been any deflate() calls since the | |
| 716 state was initialized or reset, then the input available so far is | |
| 717 compressed with the old level and strategy using deflate(strm, Z_BLOCK). | |
| 718 There are three approaches for the compression levels 0, 1..3, and 4..9 | |
| 719 respectively. The new level and strategy will take effect at the next call | |
| 720 of deflate(). | |
| 721 | |
| 722 If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does | |
| 723 not have enough output space to complete, then the parameter change will not | |
| 724 take effect. In this case, deflateParams() can be called again with the | |
| 725 same parameters and more output space to try again. | |
| 726 | |
| 727 In order to assure a change in the parameters on the first try, the | |
| 728 deflate stream should be flushed using deflate() with Z_BLOCK or other flush | |
| 729 request until strm.avail_out is not zero, before calling deflateParams(). | |
| 730 Then no more input data should be provided before the deflateParams() call. | |
| 731 If this is done, the old level and strategy will be applied to the data | |
| 732 compressed before deflateParams(), and the new level and strategy will be | |
| 733 applied to the data compressed after deflateParams(). | |
| 734 | |
| 735 deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream | |
| 736 state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if | |
| 737 there was not enough output space to complete the compression of the | |
| 738 available input data before a change in the strategy or approach. Note that | |
| 739 in the case of a Z_BUF_ERROR, the parameters are not changed. A return | |
| 740 value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be | |
| 741 retried with more output space. | |
| 742 */ | |
| 743 | |
| 744 ZEXTERN int ZEXPORT deflateTune(z_streamp strm, | |
| 745 int good_length, | |
| 746 int max_lazy, | |
| 747 int nice_length, | |
| 748 int max_chain); | |
| 749 /* | |
| 750 Fine tune deflate's internal compression parameters. This should only be | |
| 751 used by someone who understands the algorithm used by zlib's deflate for | |
| 752 searching for the best matching string, and even then only by the most | |
| 753 fanatic optimizer trying to squeeze out the last compressed bit for their | |
| 754 specific input data. Read the deflate.c source code for the meaning of the | |
| 755 max_lazy, good_length, nice_length, and max_chain parameters. | |
| 756 | |
| 757 deflateTune() can be called after deflateInit() or deflateInit2(), and | |
| 758 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. | |
| 759 */ | |
| 760 | |
| 761 ZEXTERN uLong ZEXPORT deflateBound(z_streamp strm, | |
| 762 uLong sourceLen); | |
| 763 /* | |
| 764 deflateBound() returns an upper bound on the compressed size after | |
| 765 deflation of sourceLen bytes. It must be called after deflateInit() or | |
| 766 deflateInit2(), and after deflateSetHeader(), if used. This would be used | |
| 767 to allocate an output buffer for deflation in a single pass, and so would be | |
| 768 called before deflate(). If that first deflate() call is provided the | |
| 769 sourceLen input bytes, an output buffer allocated to the size returned by | |
| 770 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed | |
| 771 to return Z_STREAM_END. Note that it is possible for the compressed size to | |
| 772 be larger than the value returned by deflateBound() if flush options other | |
| 773 than Z_FINISH or Z_NO_FLUSH are used. | |
| 774 */ | |
| 775 | |
| 776 ZEXTERN int ZEXPORT deflatePending(z_streamp strm, | |
| 777 unsigned *pending, | |
| 778 int *bits); | |
| 779 /* | |
| 780 deflatePending() returns the number of bytes and bits of output that have | |
| 781 been generated, but not yet provided in the available output. The bytes not | |
| 782 provided would be due to the available output space having being consumed. | |
| 783 The number of bits of output not provided are between 0 and 7, where they | |
| 784 await more bits to join them in order to fill out a full byte. If pending | |
| 785 or bits are Z_NULL, then those values are not set. | |
| 786 | |
| 787 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source | |
| 788 stream state was inconsistent. | |
| 789 */ | |
| 790 | |
| 791 ZEXTERN int ZEXPORT deflatePrime(z_streamp strm, | |
| 792 int bits, | |
| 793 int value); | |
| 794 /* | |
| 795 deflatePrime() inserts bits in the deflate output stream. The intent | |
| 796 is that this function is used to start off the deflate output with the bits | |
| 797 leftover from a previous deflate stream when appending to it. As such, this | |
| 798 function can only be used for raw deflate, and must be used before the first | |
| 799 deflate() call after a deflateInit2() or deflateReset(). bits must be less | |
| 800 than or equal to 16, and that many of the least significant bits of value | |
| 801 will be inserted in the output. | |
| 802 | |
| 803 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough | |
| 804 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the | |
| 805 source stream state was inconsistent. | |
| 806 */ | |
| 807 | |
| 808 ZEXTERN int ZEXPORT deflateSetHeader(z_streamp strm, | |
| 809 gz_headerp head); | |
| 810 /* | |
| 811 deflateSetHeader() provides gzip header information for when a gzip | |
| 812 stream is requested by deflateInit2(). deflateSetHeader() may be called | |
| 813 after deflateInit2() or deflateReset() and before the first call of | |
| 814 deflate(). The text, time, os, extra field, name, and comment information | |
| 815 in the provided gz_header structure are written to the gzip header (xflag is | |
| 816 ignored -- the extra flags are set according to the compression level). The | |
| 817 caller must assure that, if not Z_NULL, name and comment are terminated with | |
| 818 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are | |
| 819 available there. If hcrc is true, a gzip header crc is included. Note that | |
| 820 the current versions of the command-line version of gzip (up through version | |
| 821 1.3.x) do not support header crc's, and will report that it is a "multi-part | |
| 822 gzip file" and give up. | |
| 823 | |
| 824 If deflateSetHeader is not used, the default gzip header has text false, | |
| 825 the time set to zero, and os set to the current operating system, with no | |
| 826 extra, name, or comment fields. The gzip header is returned to the default | |
| 827 state by deflateReset(). | |
| 828 | |
| 829 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source | |
| 830 stream state was inconsistent. | |
| 831 */ | |
| 832 | |
| 833 /* | |
| 834 ZEXTERN int ZEXPORT inflateInit2(z_streamp strm, | |
| 835 int windowBits); | |
| 836 | |
| 837 This is another version of inflateInit with an extra parameter. The | |
| 838 fields next_in, avail_in, zalloc, zfree and opaque must be initialized | |
| 839 before by the caller. | |
| 840 | |
| 841 The windowBits parameter is the base two logarithm of the maximum window | |
| 842 size (the size of the history buffer). It should be in the range 8..15 for | |
| 843 this version of the library. The default value is 15 if inflateInit is used | |
| 844 instead. windowBits must be greater than or equal to the windowBits value | |
| 845 provided to deflateInit2() while compressing, or it must be equal to 15 if | |
| 846 deflateInit2() was not used. If a compressed stream with a larger window | |
| 847 size is given as input, inflate() will return with the error code | |
| 848 Z_DATA_ERROR instead of trying to allocate a larger window. | |
| 849 | |
| 850 windowBits can also be zero to request that inflate use the window size in | |
| 851 the zlib header of the compressed stream. | |
| 852 | |
| 853 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits | |
| 854 determines the window size. inflate() will then process raw deflate data, | |
| 855 not looking for a zlib or gzip header, not generating a check value, and not | |
| 856 looking for any check values for comparison at the end of the stream. This | |
| 857 is for use with other formats that use the deflate compressed data format | |
| 858 such as zip. Those formats provide their own check values. If a custom | |
| 859 format is developed using the raw deflate format for compressed data, it is | |
| 860 recommended that a check value such as an Adler-32 or a CRC-32 be applied to | |
| 861 the uncompressed data as is done in the zlib, gzip, and zip formats. For | |
| 862 most applications, the zlib format should be used as is. Note that comments | |
| 863 above on the use in deflateInit2() applies to the magnitude of windowBits. | |
| 864 | |
| 865 windowBits can also be greater than 15 for optional gzip decoding. Add | |
| 866 32 to windowBits to enable zlib and gzip decoding with automatic header | |
| 867 detection, or add 16 to decode only the gzip format (the zlib format will | |
| 868 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a | |
| 869 CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see | |
| 870 below), inflate() will *not* automatically decode concatenated gzip members. | |
| 871 inflate() will return Z_STREAM_END at the end of the gzip member. The state | |
| 872 would need to be reset to continue decoding a subsequent gzip member. This | |
| 873 *must* be done if there is more data after a gzip member, in order for the | |
| 874 decompression to be compliant with the gzip standard (RFC 1952). | |
| 875 | |
| 876 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
| 877 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the | |
| 878 version assumed by the caller, or Z_STREAM_ERROR if the parameters are | |
| 879 invalid, such as a null pointer to the structure. msg is set to null if | |
| 880 there is no error message. inflateInit2 does not perform any decompression | |
| 881 apart from possibly reading the zlib header if present: actual decompression | |
| 882 will be done by inflate(). (So next_in and avail_in may be modified, but | |
| 883 next_out and avail_out are unused and unchanged.) The current implementation | |
| 884 of inflateInit2() does not process any header information -- that is | |
| 885 deferred until inflate() is called. | |
| 886 */ | |
| 887 | |
| 888 ZEXTERN int ZEXPORT inflateSetDictionary(z_streamp strm, | |
| 889 const Bytef *dictionary, | |
| 890 uInt dictLength); | |
| 891 /* | |
| 892 Initializes the decompression dictionary from the given uncompressed byte | |
| 893 sequence. This function must be called immediately after a call of inflate, | |
| 894 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor | |
| 895 can be determined from the Adler-32 value returned by that call of inflate. | |
| 896 The compressor and decompressor must use exactly the same dictionary (see | |
| 897 deflateSetDictionary). For raw inflate, this function can be called at any | |
| 898 time to set the dictionary. If the provided dictionary is smaller than the | |
| 899 window and there is already data in the window, then the provided dictionary | |
| 900 will amend what's there. The application must insure that the dictionary | |
| 901 that was used for compression is provided. | |
| 902 | |
| 903 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a | |
| 904 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is | |
| 905 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the | |
| 906 expected one (incorrect Adler-32 value). inflateSetDictionary does not | |
| 907 perform any decompression: this will be done by subsequent calls of | |
| 908 inflate(). | |
| 909 */ | |
| 910 | |
| 911 ZEXTERN int ZEXPORT inflateGetDictionary(z_streamp strm, | |
| 912 Bytef *dictionary, | |
| 913 uInt *dictLength); | |
| 914 /* | |
| 915 Returns the sliding dictionary being maintained by inflate. dictLength is | |
| 916 set to the number of bytes in the dictionary, and that many bytes are copied | |
| 917 to dictionary. dictionary must have enough space, where 32768 bytes is | |
| 918 always enough. If inflateGetDictionary() is called with dictionary equal to | |
| 919 Z_NULL, then only the dictionary length is returned, and nothing is copied. | |
| 920 Similarly, if dictLength is Z_NULL, then it is not set. | |
| 921 | |
| 922 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the | |
| 923 stream state is inconsistent. | |
| 924 */ | |
| 925 | |
| 926 ZEXTERN int ZEXPORT inflateSync(z_streamp strm); | |
| 927 /* | |
| 928 Skips invalid compressed data until a possible full flush point (see above | |
| 929 for the description of deflate with Z_FULL_FLUSH) can be found, or until all | |
| 930 available input is skipped. No output is provided. | |
| 931 | |
| 932 inflateSync searches for a 00 00 FF FF pattern in the compressed data. | |
| 933 All full flush points have this pattern, but not all occurrences of this | |
| 934 pattern are full flush points. | |
| 935 | |
| 936 inflateSync returns Z_OK if a possible full flush point has been found, | |
| 937 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point | |
| 938 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. | |
| 939 In the success case, the application may save the current value of total_in | |
| 940 which indicates where valid compressed data was found. In the error case, | |
| 941 the application may repeatedly call inflateSync, providing more input each | |
| 942 time, until success or end of the input data. | |
| 943 */ | |
| 944 | |
| 945 ZEXTERN int ZEXPORT inflateCopy(z_streamp dest, | |
| 946 z_streamp source); | |
| 947 /* | |
| 948 Sets the destination stream as a complete copy of the source stream. | |
| 949 | |
| 950 This function can be useful when randomly accessing a large stream. The | |
| 951 first pass through the stream can periodically record the inflate state, | |
| 952 allowing restarting inflate at those points when randomly accessing the | |
| 953 stream. | |
| 954 | |
| 955 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | |
| 956 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | |
| 957 (such as zalloc being Z_NULL). msg is left unchanged in both source and | |
| 958 destination. | |
| 959 */ | |
| 960 | |
| 961 ZEXTERN int ZEXPORT inflateReset(z_streamp strm); | |
| 962 /* | |
| 963 This function is equivalent to inflateEnd followed by inflateInit, | |
| 964 but does not free and reallocate the internal decompression state. The | |
| 965 stream will keep attributes that may have been set by inflateInit2. | |
| 966 total_in, total_out, adler, and msg are initialized. | |
| 967 | |
| 968 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | |
| 969 stream state was inconsistent (such as zalloc or state being Z_NULL). | |
| 970 */ | |
| 971 | |
| 972 ZEXTERN int ZEXPORT inflateReset2(z_streamp strm, | |
| 973 int windowBits); | |
| 974 /* | |
| 975 This function is the same as inflateReset, but it also permits changing | |
| 976 the wrap and window size requests. The windowBits parameter is interpreted | |
| 977 the same as it is for inflateInit2. If the window size is changed, then the | |
| 978 memory allocated for the window is freed, and the window will be reallocated | |
| 979 by inflate() if needed. | |
| 980 | |
| 981 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source | |
| 982 stream state was inconsistent (such as zalloc or state being Z_NULL), or if | |
| 983 the windowBits parameter is invalid. | |
| 984 */ | |
| 985 | |
| 986 ZEXTERN int ZEXPORT inflatePrime(z_streamp strm, | |
| 987 int bits, | |
| 988 int value); | |
| 989 /* | |
| 990 This function inserts bits in the inflate input stream. The intent is | |
| 991 that this function is used to start inflating at a bit position in the | |
| 992 middle of a byte. The provided bits will be used before any bytes are used | |
| 993 from next_in. This function should only be used with raw inflate, and | |
| 994 should be used before the first inflate() call after inflateInit2() or | |
| 995 inflateReset(). bits must be less than or equal to 16, and that many of the | |
| 996 least significant bits of value will be inserted in the input. | |
| 997 | |
| 998 If bits is negative, then the input stream bit buffer is emptied. Then | |
| 999 inflatePrime() can be called again to put bits in the buffer. This is used | |
| 1000 to clear out bits leftover after feeding inflate a block description prior | |
| 1001 to feeding inflate codes. | |
| 1002 | |
| 1003 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source | |
| 1004 stream state was inconsistent. | |
| 1005 */ | |
| 1006 | |
| 1007 ZEXTERN long ZEXPORT inflateMark(z_streamp strm); | |
| 1008 /* | |
| 1009 This function returns two values, one in the lower 16 bits of the return | |
| 1010 value, and the other in the remaining upper bits, obtained by shifting the | |
| 1011 return value down 16 bits. If the upper value is -1 and the lower value is | |
| 1012 zero, then inflate() is currently decoding information outside of a block. | |
| 1013 If the upper value is -1 and the lower value is non-zero, then inflate is in | |
| 1014 the middle of a stored block, with the lower value equaling the number of | |
| 1015 bytes from the input remaining to copy. If the upper value is not -1, then | |
| 1016 it is the number of bits back from the current bit position in the input of | |
| 1017 the code (literal or length/distance pair) currently being processed. In | |
| 1018 that case the lower value is the number of bytes already emitted for that | |
| 1019 code. | |
| 1020 | |
| 1021 A code is being processed if inflate is waiting for more input to complete | |
| 1022 decoding of the code, or if it has completed decoding but is waiting for | |
| 1023 more output space to write the literal or match data. | |
| 1024 | |
| 1025 inflateMark() is used to mark locations in the input data for random | |
| 1026 access, which may be at bit positions, and to note those cases where the | |
| 1027 output of a code may span boundaries of random access blocks. The current | |
| 1028 location in the input stream can be determined from avail_in and data_type | |
| 1029 as noted in the description for the Z_BLOCK flush parameter for inflate. | |
| 1030 | |
| 1031 inflateMark returns the value noted above, or -65536 if the provided | |
| 1032 source stream state was inconsistent. | |
| 1033 */ | |
| 1034 | |
| 1035 ZEXTERN int ZEXPORT inflateGetHeader(z_streamp strm, | |
| 1036 gz_headerp head); | |
| 1037 /* | |
| 1038 inflateGetHeader() requests that gzip header information be stored in the | |
| 1039 provided gz_header structure. inflateGetHeader() may be called after | |
| 1040 inflateInit2() or inflateReset(), and before the first call of inflate(). | |
| 1041 As inflate() processes the gzip stream, head->done is zero until the header | |
| 1042 is completed, at which time head->done is set to one. If a zlib stream is | |
| 1043 being decoded, then head->done is set to -1 to indicate that there will be | |
| 1044 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be | |
| 1045 used to force inflate() to return immediately after header processing is | |
| 1046 complete and before any actual data is decompressed. | |
| 1047 | |
| 1048 The text, time, xflags, and os fields are filled in with the gzip header | |
| 1049 contents. hcrc is set to true if there is a header CRC. (The header CRC | |
| 1050 was valid if done is set to one.) If extra is not Z_NULL, then extra_max | |
| 1051 contains the maximum number of bytes to write to extra. Once done is true, | |
| 1052 extra_len contains the actual extra field length, and extra contains the | |
| 1053 extra field, or that field truncated if extra_max is less than extra_len. | |
| 1054 If name is not Z_NULL, then up to name_max characters are written there, | |
| 1055 terminated with a zero unless the length is greater than name_max. If | |
| 1056 comment is not Z_NULL, then up to comm_max characters are written there, | |
| 1057 terminated with a zero unless the length is greater than comm_max. When any | |
| 1058 of extra, name, or comment are not Z_NULL and the respective field is not | |
| 1059 present in the header, then that field is set to Z_NULL to signal its | |
| 1060 absence. This allows the use of deflateSetHeader() with the returned | |
| 1061 structure to duplicate the header. However if those fields are set to | |
| 1062 allocated memory, then the application will need to save those pointers | |
| 1063 elsewhere so that they can be eventually freed. | |
| 1064 | |
| 1065 If inflateGetHeader is not used, then the header information is simply | |
| 1066 discarded. The header is always checked for validity, including the header | |
| 1067 CRC if present. inflateReset() will reset the process to discard the header | |
| 1068 information. The application would need to call inflateGetHeader() again to | |
| 1069 retrieve the header from the next gzip stream. | |
| 1070 | |
| 1071 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source | |
| 1072 stream state was inconsistent. | |
| 1073 */ | |
| 1074 | |
| 1075 /* | |
| 1076 ZEXTERN int ZEXPORT inflateBackInit(z_streamp strm, int windowBits, | |
| 1077 unsigned char FAR *window); | |
| 1078 | |
| 1079 Initialize the internal stream state for decompression using inflateBack() | |
| 1080 calls. The fields zalloc, zfree and opaque in strm must be initialized | |
| 1081 before the call. If zalloc and zfree are Z_NULL, then the default library- | |
| 1082 derived memory allocation routines are used. windowBits is the base two | |
| 1083 logarithm of the window size, in the range 8..15. window is a caller | |
| 1084 supplied buffer of that size. Except for special applications where it is | |
| 1085 assured that deflate was used with small window sizes, windowBits must be 15 | |
| 1086 and a 32K byte window must be supplied to be able to decompress general | |
| 1087 deflate streams. | |
| 1088 | |
| 1089 See inflateBack() for the usage of these routines. | |
| 1090 | |
| 1091 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of | |
| 1092 the parameters are invalid, Z_MEM_ERROR if the internal state could not be | |
| 1093 allocated, or Z_VERSION_ERROR if the version of the library does not match | |
| 1094 the version of the header file. | |
| 1095 */ | |
| 1096 | |
| 1097 typedef unsigned (*in_func)(void FAR *, | |
| 1098 z_const unsigned char FAR * FAR *); | |
| 1099 typedef int (*out_func)(void FAR *, unsigned char FAR *, unsigned); | |
| 1100 | |
| 1101 ZEXTERN int ZEXPORT inflateBack(z_streamp strm, | |
| 1102 in_func in, void FAR *in_desc, | |
| 1103 out_func out, void FAR *out_desc); | |
| 1104 /* | |
| 1105 inflateBack() does a raw inflate with a single call using a call-back | |
| 1106 interface for input and output. This is potentially more efficient than | |
| 1107 inflate() for file i/o applications, in that it avoids copying between the | |
| 1108 output and the sliding window by simply making the window itself the output | |
| 1109 buffer. inflate() can be faster on modern CPUs when used with large | |
| 1110 buffers. inflateBack() trusts the application to not change the output | |
| 1111 buffer passed by the output function, at least until inflateBack() returns. | |
| 1112 | |
| 1113 inflateBackInit() must be called first to allocate the internal state | |
| 1114 and to initialize the state with the user-provided window buffer. | |
| 1115 inflateBack() may then be used multiple times to inflate a complete, raw | |
| 1116 deflate stream with each call. inflateBackEnd() is then called to free the | |
| 1117 allocated state. | |
| 1118 | |
| 1119 A raw deflate stream is one with no zlib or gzip header or trailer. | |
| 1120 This routine would normally be used in a utility that reads zip or gzip | |
| 1121 files and writes out uncompressed files. The utility would decode the | |
| 1122 header and process the trailer on its own, hence this routine expects only | |
| 1123 the raw deflate stream to decompress. This is different from the default | |
| 1124 behavior of inflate(), which expects a zlib header and trailer around the | |
| 1125 deflate stream. | |
| 1126 | |
| 1127 inflateBack() uses two subroutines supplied by the caller that are then | |
| 1128 called by inflateBack() for input and output. inflateBack() calls those | |
| 1129 routines until it reads a complete deflate stream and writes out all of the | |
| 1130 uncompressed data, or until it encounters an error. The function's | |
| 1131 parameters and return types are defined above in the in_func and out_func | |
| 1132 typedefs. inflateBack() will call in(in_desc, &buf) which should return the | |
| 1133 number of bytes of provided input, and a pointer to that input in buf. If | |
| 1134 there is no input available, in() must return zero -- buf is ignored in that | |
| 1135 case -- and inflateBack() will return a buffer error. inflateBack() will | |
| 1136 call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. | |
| 1137 out() should return zero on success, or non-zero on failure. If out() | |
| 1138 returns non-zero, inflateBack() will return with an error. Neither in() nor | |
| 1139 out() are permitted to change the contents of the window provided to | |
| 1140 inflateBackInit(), which is also the buffer that out() uses to write from. | |
| 1141 The length written by out() will be at most the window size. Any non-zero | |
| 1142 amount of input may be provided by in(). | |
| 1143 | |
| 1144 For convenience, inflateBack() can be provided input on the first call by | |
| 1145 setting strm->next_in and strm->avail_in. If that input is exhausted, then | |
| 1146 in() will be called. Therefore strm->next_in must be initialized before | |
| 1147 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called | |
| 1148 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in | |
| 1149 must also be initialized, and then if strm->avail_in is not zero, input will | |
| 1150 initially be taken from strm->next_in[0 .. strm->avail_in - 1]. | |
| 1151 | |
| 1152 The in_desc and out_desc parameters of inflateBack() is passed as the | |
| 1153 first parameter of in() and out() respectively when they are called. These | |
| 1154 descriptors can be optionally used to pass any information that the caller- | |
| 1155 supplied in() and out() functions need to do their job. | |
| 1156 | |
| 1157 On return, inflateBack() will set strm->next_in and strm->avail_in to | |
| 1158 pass back any unused input that was provided by the last in() call. The | |
| 1159 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR | |
| 1160 if in() or out() returned an error, Z_DATA_ERROR if there was a format error | |
| 1161 in the deflate stream (in which case strm->msg is set to indicate the nature | |
| 1162 of the error), or Z_STREAM_ERROR if the stream was not properly initialized. | |
| 1163 In the case of Z_BUF_ERROR, an input or output error can be distinguished | |
| 1164 using strm->next_in which will be Z_NULL only if in() returned an error. If | |
| 1165 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning | |
| 1166 non-zero. (in() will always be called before out(), so strm->next_in is | |
| 1167 assured to be defined if out() returns non-zero.) Note that inflateBack() | |
| 1168 cannot return Z_OK. | |
| 1169 */ | |
| 1170 | |
| 1171 ZEXTERN int ZEXPORT inflateBackEnd(z_streamp strm); | |
| 1172 /* | |
| 1173 All memory allocated by inflateBackInit() is freed. | |
| 1174 | |
| 1175 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream | |
| 1176 state was inconsistent. | |
| 1177 */ | |
| 1178 | |
| 1179 ZEXTERN uLong ZEXPORT zlibCompileFlags(void); | |
| 1180 /* Return flags indicating compile-time options. | |
| 1181 | |
| 1182 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: | |
| 1183 1.0: size of uInt | |
| 1184 3.2: size of uLong | |
| 1185 5.4: size of voidpf (pointer) | |
| 1186 7.6: size of z_off_t | |
| 1187 | |
| 1188 Compiler, assembler, and debug options: | |
| 1189 8: ZLIB_DEBUG | |
| 1190 9: ASMV or ASMINF -- use ASM code | |
| 1191 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention | |
| 1192 11: 0 (reserved) | |
| 1193 | |
| 1194 One-time table building (smaller code, but not thread-safe if true): | |
| 1195 12: BUILDFIXED -- build static block decoding tables when needed | |
| 1196 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed | |
| 1197 14,15: 0 (reserved) | |
| 1198 | |
| 1199 Library content (indicates missing functionality): | |
| 1200 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking | |
| 1201 deflate code when not needed) | |
| 1202 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect | |
| 1203 and decode gzip streams (to avoid linking crc code) | |
| 1204 18-19: 0 (reserved) | |
| 1205 | |
| 1206 Operation variations (changes in library functionality): | |
| 1207 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate | |
| 1208 21: FASTEST -- deflate algorithm with only one, lowest compression level | |
| 1209 22,23: 0 (reserved) | |
| 1210 | |
| 1211 The sprintf variant used by gzprintf (zero is best): | |
| 1212 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format | |
| 1213 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! | |
| 1214 26: 0 = returns value, 1 = void -- 1 means inferred string length returned | |
| 1215 | |
| 1216 Remainder: | |
| 1217 27-31: 0 (reserved) | |
| 1218 */ | |
| 1219 | |
| 1220 #ifndef Z_SOLO | |
| 1221 | |
| 1222 /* utility functions */ | |
| 1223 | |
| 1224 /* | |
| 1225 The following utility functions are implemented on top of the basic | |
| 1226 stream-oriented functions. To simplify the interface, some default options | |
| 1227 are assumed (compression level and memory usage, standard memory allocation | |
| 1228 functions). The source code of these utility functions can be modified if | |
| 1229 you need special options. | |
| 1230 */ | |
| 1231 | |
| 1232 ZEXTERN int ZEXPORT compress(Bytef *dest, uLongf *destLen, | |
| 1233 const Bytef *source, uLong sourceLen); | |
| 1234 /* | |
| 1235 Compresses the source buffer into the destination buffer. sourceLen is | |
| 1236 the byte length of the source buffer. Upon entry, destLen is the total size | |
| 1237 of the destination buffer, which must be at least the value returned by | |
| 1238 compressBound(sourceLen). Upon exit, destLen is the actual size of the | |
| 1239 compressed data. compress() is equivalent to compress2() with a level | |
| 1240 parameter of Z_DEFAULT_COMPRESSION. | |
| 1241 | |
| 1242 compress returns Z_OK if success, Z_MEM_ERROR if there was not | |
| 1243 enough memory, Z_BUF_ERROR if there was not enough room in the output | |
| 1244 buffer. | |
| 1245 */ | |
| 1246 | |
| 1247 ZEXTERN int ZEXPORT compress2(Bytef *dest, uLongf *destLen, | |
| 1248 const Bytef *source, uLong sourceLen, | |
| 1249 int level); | |
| 1250 /* | |
| 1251 Compresses the source buffer into the destination buffer. The level | |
| 1252 parameter has the same meaning as in deflateInit. sourceLen is the byte | |
| 1253 length of the source buffer. Upon entry, destLen is the total size of the | |
| 1254 destination buffer, which must be at least the value returned by | |
| 1255 compressBound(sourceLen). Upon exit, destLen is the actual size of the | |
| 1256 compressed data. | |
| 1257 | |
| 1258 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
| 1259 memory, Z_BUF_ERROR if there was not enough room in the output buffer, | |
| 1260 Z_STREAM_ERROR if the level parameter is invalid. | |
| 1261 */ | |
| 1262 | |
| 1263 ZEXTERN uLong ZEXPORT compressBound(uLong sourceLen); | |
| 1264 /* | |
| 1265 compressBound() returns an upper bound on the compressed size after | |
| 1266 compress() or compress2() on sourceLen bytes. It would be used before a | |
| 1267 compress() or compress2() call to allocate the destination buffer. | |
| 1268 */ | |
| 1269 | |
| 1270 ZEXTERN int ZEXPORT uncompress(Bytef *dest, uLongf *destLen, | |
| 1271 const Bytef *source, uLong sourceLen); | |
| 1272 /* | |
| 1273 Decompresses the source buffer into the destination buffer. sourceLen is | |
| 1274 the byte length of the source buffer. Upon entry, destLen is the total size | |
| 1275 of the destination buffer, which must be large enough to hold the entire | |
| 1276 uncompressed data. (The size of the uncompressed data must have been saved | |
| 1277 previously by the compressor and transmitted to the decompressor by some | |
| 1278 mechanism outside the scope of this compression library.) Upon exit, destLen | |
| 1279 is the actual size of the uncompressed data. | |
| 1280 | |
| 1281 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not | |
| 1282 enough memory, Z_BUF_ERROR if there was not enough room in the output | |
| 1283 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In | |
| 1284 the case where there is not enough room, uncompress() will fill the output | |
| 1285 buffer with the uncompressed data up to that point. | |
| 1286 */ | |
| 1287 | |
| 1288 ZEXTERN int ZEXPORT uncompress2(Bytef *dest, uLongf *destLen, | |
| 1289 const Bytef *source, uLong *sourceLen); | |
| 1290 /* | |
| 1291 Same as uncompress, except that sourceLen is a pointer, where the | |
| 1292 length of the source is *sourceLen. On return, *sourceLen is the number of | |
| 1293 source bytes consumed. | |
| 1294 */ | |
| 1295 | |
| 1296 /* gzip file access functions */ | |
| 1297 | |
| 1298 /* | |
| 1299 This library supports reading and writing files in gzip (.gz) format with | |
| 1300 an interface similar to that of stdio, using the functions that start with | |
| 1301 "gz". The gzip format is different from the zlib format. gzip is a gzip | |
| 1302 wrapper, documented in RFC 1952, wrapped around a deflate stream. | |
| 1303 */ | |
| 1304 | |
| 1305 typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ | |
| 1306 | |
| 1307 /* | |
| 1308 ZEXTERN gzFile ZEXPORT gzopen(const char *path, const char *mode); | |
| 1309 | |
| 1310 Open the gzip (.gz) file at path for reading and decompressing, or | |
| 1311 compressing and writing. The mode parameter is as in fopen ("rb" or "wb") | |
| 1312 but can also include a compression level ("wb9") or a strategy: 'f' for | |
| 1313 filtered data as in "wb6f", 'h' for Huffman-only compression as in "wb1h", | |
| 1314 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression | |
| 1315 as in "wb9F". (See the description of deflateInit2 for more information | |
| 1316 about the strategy parameter.) 'T' will request transparent writing or | |
| 1317 appending with no compression and not using the gzip format. | |
| 1318 | |
| 1319 "a" can be used instead of "w" to request that the gzip stream that will | |
| 1320 be written be appended to the file. "+" will result in an error, since | |
| 1321 reading and writing to the same gzip file is not supported. The addition of | |
| 1322 "x" when writing will create the file exclusively, which fails if the file | |
| 1323 already exists. On systems that support it, the addition of "e" when | |
| 1324 reading or writing will set the flag to close the file on an execve() call. | |
| 1325 | |
| 1326 These functions, as well as gzip, will read and decode a sequence of gzip | |
| 1327 streams in a file. The append function of gzopen() can be used to create | |
| 1328 such a file. (Also see gzflush() for another way to do this.) When | |
| 1329 appending, gzopen does not test whether the file begins with a gzip stream, | |
| 1330 nor does it look for the end of the gzip streams to begin appending. gzopen | |
| 1331 will simply append a gzip stream to the existing file. | |
| 1332 | |
| 1333 gzopen can be used to read a file which is not in gzip format; in this | |
| 1334 case gzread will directly read from the file without decompression. When | |
| 1335 reading, this will be detected automatically by looking for the magic two- | |
| 1336 byte gzip header. | |
| 1337 | |
| 1338 gzopen returns NULL if the file could not be opened, if there was | |
| 1339 insufficient memory to allocate the gzFile state, or if an invalid mode was | |
| 1340 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). | |
| 1341 errno can be checked to determine if the reason gzopen failed was that the | |
| 1342 file could not be opened. | |
| 1343 */ | |
| 1344 | |
| 1345 ZEXTERN gzFile ZEXPORT gzdopen(int fd, const char *mode); | |
| 1346 /* | |
| 1347 Associate a gzFile with the file descriptor fd. File descriptors are | |
| 1348 obtained from calls like open, dup, creat, pipe or fileno (if the file has | |
| 1349 been previously opened with fopen). The mode parameter is as in gzopen. | |
| 1350 | |
| 1351 The next call of gzclose on the returned gzFile will also close the file | |
| 1352 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor | |
| 1353 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, | |
| 1354 mode);. The duplicated descriptor should be saved to avoid a leak, since | |
| 1355 gzdopen does not close fd if it fails. If you are using fileno() to get the | |
| 1356 file descriptor from a FILE *, then you will have to use dup() to avoid | |
| 1357 double-close()ing the file descriptor. Both gzclose() and fclose() will | |
| 1358 close the associated file descriptor, so they need to have different file | |
| 1359 descriptors. | |
| 1360 | |
| 1361 gzdopen returns NULL if there was insufficient memory to allocate the | |
| 1362 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not | |
| 1363 provided, or '+' was provided), or if fd is -1. The file descriptor is not | |
| 1364 used until the next gz* read, write, seek, or close operation, so gzdopen | |
| 1365 will not detect if fd is invalid (unless fd is -1). | |
| 1366 */ | |
| 1367 | |
| 1368 ZEXTERN int ZEXPORT gzbuffer(gzFile file, unsigned size); | |
| 1369 /* | |
| 1370 Set the internal buffer size used by this library's functions for file to | |
| 1371 size. The default buffer size is 8192 bytes. This function must be called | |
| 1372 after gzopen() or gzdopen(), and before any other calls that read or write | |
| 1373 the file. The buffer memory allocation is always deferred to the first read | |
| 1374 or write. Three times that size in buffer space is allocated. A larger | |
| 1375 buffer size of, for example, 64K or 128K bytes will noticeably increase the | |
| 1376 speed of decompression (reading). | |
| 1377 | |
| 1378 The new buffer size also affects the maximum length for gzprintf(). | |
| 1379 | |
| 1380 gzbuffer() returns 0 on success, or -1 on failure, such as being called | |
| 1381 too late. | |
| 1382 */ | |
| 1383 | |
| 1384 ZEXTERN int ZEXPORT gzsetparams(gzFile file, int level, int strategy); | |
| 1385 /* | |
| 1386 Dynamically update the compression level and strategy for file. See the | |
| 1387 description of deflateInit2 for the meaning of these parameters. Previously | |
| 1388 provided data is flushed before applying the parameter changes. | |
| 1389 | |
| 1390 gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not | |
| 1391 opened for writing, Z_ERRNO if there is an error writing the flushed data, | |
| 1392 or Z_MEM_ERROR if there is a memory allocation error. | |
| 1393 */ | |
| 1394 | |
| 1395 ZEXTERN int ZEXPORT gzread(gzFile file, voidp buf, unsigned len); | |
| 1396 /* | |
| 1397 Read and decompress up to len uncompressed bytes from file into buf. If | |
| 1398 the input file is not in gzip format, gzread copies the given number of | |
| 1399 bytes into the buffer directly from the file. | |
| 1400 | |
| 1401 After reaching the end of a gzip stream in the input, gzread will continue | |
| 1402 to read, looking for another gzip stream. Any number of gzip streams may be | |
| 1403 concatenated in the input file, and will all be decompressed by gzread(). | |
| 1404 If something other than a gzip stream is encountered after a gzip stream, | |
| 1405 that remaining trailing garbage is ignored (and no error is returned). | |
| 1406 | |
| 1407 gzread can be used to read a gzip file that is being concurrently written. | |
| 1408 Upon reaching the end of the input, gzread will return with the available | |
| 1409 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then | |
| 1410 gzclearerr can be used to clear the end of file indicator in order to permit | |
| 1411 gzread to be tried again. Z_OK indicates that a gzip stream was completed | |
| 1412 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the | |
| 1413 middle of a gzip stream. Note that gzread does not return -1 in the event | |
| 1414 of an incomplete gzip stream. This error is deferred until gzclose(), which | |
| 1415 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip | |
| 1416 stream. Alternatively, gzerror can be used before gzclose to detect this | |
| 1417 case. | |
| 1418 | |
| 1419 gzread returns the number of uncompressed bytes actually read, less than | |
| 1420 len for end of file, or -1 for error. If len is too large to fit in an int, | |
| 1421 then nothing is read, -1 is returned, and the error state is set to | |
| 1422 Z_STREAM_ERROR. | |
| 1423 */ | |
| 1424 | |
| 1425 ZEXTERN z_size_t ZEXPORT gzfread(voidp buf, z_size_t size, z_size_t nitems, | |
| 1426 gzFile file); | |
| 1427 /* | |
| 1428 Read and decompress up to nitems items of size size from file into buf, | |
| 1429 otherwise operating as gzread() does. This duplicates the interface of | |
| 1430 stdio's fread(), with size_t request and return types. If the library | |
| 1431 defines size_t, then z_size_t is identical to size_t. If not, then z_size_t | |
| 1432 is an unsigned integer type that can contain a pointer. | |
| 1433 | |
| 1434 gzfread() returns the number of full items read of size size, or zero if | |
| 1435 the end of the file was reached and a full item could not be read, or if | |
| 1436 there was an error. gzerror() must be consulted if zero is returned in | |
| 1437 order to determine if there was an error. If the multiplication of size and | |
| 1438 nitems overflows, i.e. the product does not fit in a z_size_t, then nothing | |
| 1439 is read, zero is returned, and the error state is set to Z_STREAM_ERROR. | |
| 1440 | |
| 1441 In the event that the end of file is reached and only a partial item is | |
| 1442 available at the end, i.e. the remaining uncompressed data length is not a | |
| 1443 multiple of size, then the final partial item is nevertheless read into buf | |
| 1444 and the end-of-file flag is set. The length of the partial item read is not | |
| 1445 provided, but could be inferred from the result of gztell(). This behavior | |
| 1446 is the same as the behavior of fread() implementations in common libraries, | |
| 1447 but it prevents the direct use of gzfread() to read a concurrently written | |
| 1448 file, resetting and retrying on end-of-file, when size is not 1. | |
| 1449 */ | |
| 1450 | |
| 1451 ZEXTERN int ZEXPORT gzwrite(gzFile file, voidpc buf, unsigned len); | |
| 1452 /* | |
| 1453 Compress and write the len uncompressed bytes at buf to file. gzwrite | |
| 1454 returns the number of uncompressed bytes written or 0 in case of error. | |
| 1455 */ | |
| 1456 | |
| 1457 ZEXTERN z_size_t ZEXPORT gzfwrite(voidpc buf, z_size_t size, | |
| 1458 z_size_t nitems, gzFile file); | |
| 1459 /* | |
| 1460 Compress and write nitems items of size size from buf to file, duplicating | |
| 1461 the interface of stdio's fwrite(), with size_t request and return types. If | |
| 1462 the library defines size_t, then z_size_t is identical to size_t. If not, | |
| 1463 then z_size_t is an unsigned integer type that can contain a pointer. | |
| 1464 | |
| 1465 gzfwrite() returns the number of full items written of size size, or zero | |
| 1466 if there was an error. If the multiplication of size and nitems overflows, | |
| 1467 i.e. the product does not fit in a z_size_t, then nothing is written, zero | |
| 1468 is returned, and the error state is set to Z_STREAM_ERROR. | |
| 1469 */ | |
| 1470 | |
| 1471 ZEXTERN int ZEXPORTVA gzprintf(gzFile file, const char *format, ...); | |
| 1472 /* | |
| 1473 Convert, format, compress, and write the arguments (...) to file under | |
| 1474 control of the string format, as in fprintf. gzprintf returns the number of | |
| 1475 uncompressed bytes actually written, or a negative zlib error code in case | |
| 1476 of error. The number of uncompressed bytes written is limited to 8191, or | |
| 1477 one less than the buffer size given to gzbuffer(). The caller should assure | |
| 1478 that this limit is not exceeded. If it is exceeded, then gzprintf() will | |
| 1479 return an error (0) with nothing written. In this case, there may also be a | |
| 1480 buffer overflow with unpredictable consequences, which is possible only if | |
| 1481 zlib was compiled with the insecure functions sprintf() or vsprintf(), | |
| 1482 because the secure snprintf() or vsnprintf() functions were not available. | |
| 1483 This can be determined using zlibCompileFlags(). | |
| 1484 */ | |
| 1485 | |
| 1486 ZEXTERN int ZEXPORT gzputs(gzFile file, const char *s); | |
| 1487 /* | |
| 1488 Compress and write the given null-terminated string s to file, excluding | |
| 1489 the terminating null character. | |
| 1490 | |
| 1491 gzputs returns the number of characters written, or -1 in case of error. | |
| 1492 */ | |
| 1493 | |
| 1494 ZEXTERN char * ZEXPORT gzgets(gzFile file, char *buf, int len); | |
| 1495 /* | |
| 1496 Read and decompress bytes from file into buf, until len-1 characters are | |
| 1497 read, or until a newline character is read and transferred to buf, or an | |
| 1498 end-of-file condition is encountered. If any characters are read or if len | |
| 1499 is one, the string is terminated with a null character. If no characters | |
| 1500 are read due to an end-of-file or len is less than one, then the buffer is | |
| 1501 left untouched. | |
| 1502 | |
| 1503 gzgets returns buf which is a null-terminated string, or it returns NULL | |
| 1504 for end-of-file or in case of error. If there was an error, the contents at | |
| 1505 buf are indeterminate. | |
| 1506 */ | |
| 1507 | |
| 1508 ZEXTERN int ZEXPORT gzputc(gzFile file, int c); | |
| 1509 /* | |
| 1510 Compress and write c, converted to an unsigned char, into file. gzputc | |
| 1511 returns the value that was written, or -1 in case of error. | |
| 1512 */ | |
| 1513 | |
| 1514 ZEXTERN int ZEXPORT gzgetc(gzFile file); | |
| 1515 /* | |
| 1516 Read and decompress one byte from file. gzgetc returns this byte or -1 | |
| 1517 in case of end of file or error. This is implemented as a macro for speed. | |
| 1518 As such, it does not do all of the checking the other functions do. I.e. | |
| 1519 it does not check to see if file is NULL, nor whether the structure file | |
| 1520 points to has been clobbered or not. | |
| 1521 */ | |
| 1522 | |
| 1523 ZEXTERN int ZEXPORT gzungetc(int c, gzFile file); | |
| 1524 /* | |
| 1525 Push c back onto the stream for file to be read as the first character on | |
| 1526 the next read. At least one character of push-back is always allowed. | |
| 1527 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will | |
| 1528 fail if c is -1, and may fail if a character has been pushed but not read | |
| 1529 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the | |
| 1530 output buffer size of pushed characters is allowed. (See gzbuffer above.) | |
| 1531 The pushed character will be discarded if the stream is repositioned with | |
| 1532 gzseek() or gzrewind(). | |
| 1533 */ | |
| 1534 | |
| 1535 ZEXTERN int ZEXPORT gzflush(gzFile file, int flush); | |
| 1536 /* | |
| 1537 Flush all pending output to file. The parameter flush is as in the | |
| 1538 deflate() function. The return value is the zlib error number (see function | |
| 1539 gzerror below). gzflush is only permitted when writing. | |
| 1540 | |
| 1541 If the flush parameter is Z_FINISH, the remaining data is written and the | |
| 1542 gzip stream is completed in the output. If gzwrite() is called again, a new | |
| 1543 gzip stream will be started in the output. gzread() is able to read such | |
| 1544 concatenated gzip streams. | |
| 1545 | |
| 1546 gzflush should be called only when strictly necessary because it will | |
| 1547 degrade compression if called too often. | |
| 1548 */ | |
| 1549 | |
| 1550 /* | |
| 1551 ZEXTERN z_off_t ZEXPORT gzseek(gzFile file, | |
| 1552 z_off_t offset, int whence); | |
| 1553 | |
| 1554 Set the starting position to offset relative to whence for the next gzread | |
| 1555 or gzwrite on file. The offset represents a number of bytes in the | |
| 1556 uncompressed data stream. The whence parameter is defined as in lseek(2); | |
| 1557 the value SEEK_END is not supported. | |
| 1558 | |
| 1559 If the file is opened for reading, this function is emulated but can be | |
| 1560 extremely slow. If the file is opened for writing, only forward seeks are | |
| 1561 supported; gzseek then compresses a sequence of zeroes up to the new | |
| 1562 starting position. | |
| 1563 | |
| 1564 gzseek returns the resulting offset location as measured in bytes from | |
| 1565 the beginning of the uncompressed stream, or -1 in case of error, in | |
| 1566 particular if the file is opened for writing and the new starting position | |
| 1567 would be before the current position. | |
| 1568 */ | |
| 1569 | |
| 1570 ZEXTERN int ZEXPORT gzrewind(gzFile file); | |
| 1571 /* | |
| 1572 Rewind file. This function is supported only for reading. | |
| 1573 | |
| 1574 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET). | |
| 1575 */ | |
| 1576 | |
| 1577 /* | |
| 1578 ZEXTERN z_off_t ZEXPORT gztell(gzFile file); | |
| 1579 | |
| 1580 Return the starting position for the next gzread or gzwrite on file. | |
| 1581 This position represents a number of bytes in the uncompressed data stream, | |
| 1582 and is zero when starting, even if appending or reading a gzip stream from | |
| 1583 the middle of a file using gzdopen(). | |
| 1584 | |
| 1585 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) | |
| 1586 */ | |
| 1587 | |
| 1588 /* | |
| 1589 ZEXTERN z_off_t ZEXPORT gzoffset(gzFile file); | |
| 1590 | |
| 1591 Return the current compressed (actual) read or write offset of file. This | |
| 1592 offset includes the count of bytes that precede the gzip stream, for example | |
| 1593 when appending or when using gzdopen() for reading. When reading, the | |
| 1594 offset does not include as yet unused buffered input. This information can | |
| 1595 be used for a progress indicator. On error, gzoffset() returns -1. | |
| 1596 */ | |
| 1597 | |
| 1598 ZEXTERN int ZEXPORT gzeof(gzFile file); | |
| 1599 /* | |
| 1600 Return true (1) if the end-of-file indicator for file has been set while | |
| 1601 reading, false (0) otherwise. Note that the end-of-file indicator is set | |
| 1602 only if the read tried to go past the end of the input, but came up short. | |
| 1603 Therefore, just like feof(), gzeof() may return false even if there is no | |
| 1604 more data to read, in the event that the last read request was for the exact | |
| 1605 number of bytes remaining in the input file. This will happen if the input | |
| 1606 file size is an exact multiple of the buffer size. | |
| 1607 | |
| 1608 If gzeof() returns true, then the read functions will return no more data, | |
| 1609 unless the end-of-file indicator is reset by gzclearerr() and the input file | |
| 1610 has grown since the previous end of file was detected. | |
| 1611 */ | |
| 1612 | |
| 1613 ZEXTERN int ZEXPORT gzdirect(gzFile file); | |
| 1614 /* | |
| 1615 Return true (1) if file is being copied directly while reading, or false | |
| 1616 (0) if file is a gzip stream being decompressed. | |
| 1617 | |
| 1618 If the input file is empty, gzdirect() will return true, since the input | |
| 1619 does not contain a gzip stream. | |
| 1620 | |
| 1621 If gzdirect() is used immediately after gzopen() or gzdopen() it will | |
| 1622 cause buffers to be allocated to allow reading the file to determine if it | |
| 1623 is a gzip file. Therefore if gzbuffer() is used, it should be called before | |
| 1624 gzdirect(). | |
| 1625 | |
| 1626 When writing, gzdirect() returns true (1) if transparent writing was | |
| 1627 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: | |
| 1628 gzdirect() is not needed when writing. Transparent writing must be | |
| 1629 explicitly requested, so the application already knows the answer. When | |
| 1630 linking statically, using gzdirect() will include all of the zlib code for | |
| 1631 gzip file reading and decompression, which may not be desired.) | |
| 1632 */ | |
| 1633 | |
| 1634 ZEXTERN int ZEXPORT gzclose(gzFile file); | |
| 1635 /* | |
| 1636 Flush all pending output for file, if necessary, close file and | |
| 1637 deallocate the (de)compression state. Note that once file is closed, you | |
| 1638 cannot call gzerror with file, since its structures have been deallocated. | |
| 1639 gzclose must not be called more than once on the same file, just as free | |
| 1640 must not be called more than once on the same allocation. | |
| 1641 | |
| 1642 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a | |
| 1643 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the | |
| 1644 last read ended in the middle of a gzip stream, or Z_OK on success. | |
| 1645 */ | |
| 1646 | |
| 1647 ZEXTERN int ZEXPORT gzclose_r(gzFile file); | |
| 1648 ZEXTERN int ZEXPORT gzclose_w(gzFile file); | |
| 1649 /* | |
| 1650 Same as gzclose(), but gzclose_r() is only for use when reading, and | |
| 1651 gzclose_w() is only for use when writing or appending. The advantage to | |
| 1652 using these instead of gzclose() is that they avoid linking in zlib | |
| 1653 compression or decompression code that is not used when only reading or only | |
| 1654 writing respectively. If gzclose() is used, then both compression and | |
| 1655 decompression code will be included the application when linking to a static | |
| 1656 zlib library. | |
| 1657 */ | |
| 1658 | |
| 1659 ZEXTERN const char * ZEXPORT gzerror(gzFile file, int *errnum); | |
| 1660 /* | |
| 1661 Return the error message for the last error which occurred on file. | |
| 1662 errnum is set to zlib error number. If an error occurred in the file system | |
| 1663 and not in the compression library, errnum is set to Z_ERRNO and the | |
| 1664 application may consult errno to get the exact error code. | |
| 1665 | |
| 1666 The application must not modify the returned string. Future calls to | |
| 1667 this function may invalidate the previously returned string. If file is | |
| 1668 closed, then the string previously returned by gzerror will no longer be | |
| 1669 available. | |
| 1670 | |
| 1671 gzerror() should be used to distinguish errors from end-of-file for those | |
| 1672 functions above that do not distinguish those cases in their return values. | |
| 1673 */ | |
| 1674 | |
| 1675 ZEXTERN void ZEXPORT gzclearerr(gzFile file); | |
| 1676 /* | |
| 1677 Clear the error and end-of-file flags for file. This is analogous to the | |
| 1678 clearerr() function in stdio. This is useful for continuing to read a gzip | |
| 1679 file that is being written concurrently. | |
| 1680 */ | |
| 1681 | |
| 1682 #endif /* !Z_SOLO */ | |
| 1683 | |
| 1684 /* checksum functions */ | |
| 1685 | |
| 1686 /* | |
| 1687 These functions are not related to compression but are exported | |
| 1688 anyway because they might be useful in applications using the compression | |
| 1689 library. | |
| 1690 */ | |
| 1691 | |
| 1692 ZEXTERN uLong ZEXPORT adler32(uLong adler, const Bytef *buf, uInt len); | |
| 1693 /* | |
| 1694 Update a running Adler-32 checksum with the bytes buf[0..len-1] and | |
| 1695 return the updated checksum. An Adler-32 value is in the range of a 32-bit | |
| 1696 unsigned integer. If buf is Z_NULL, this function returns the required | |
| 1697 initial value for the checksum. | |
| 1698 | |
| 1699 An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed | |
| 1700 much faster. | |
| 1701 | |
| 1702 Usage example: | |
| 1703 | |
| 1704 uLong adler = adler32(0L, Z_NULL, 0); | |
| 1705 | |
| 1706 while (read_buffer(buffer, length) != EOF) { | |
| 1707 adler = adler32(adler, buffer, length); | |
| 1708 } | |
| 1709 if (adler != original_adler) error(); | |
| 1710 */ | |
| 1711 | |
| 1712 ZEXTERN uLong ZEXPORT adler32_z(uLong adler, const Bytef *buf, | |
| 1713 z_size_t len); | |
| 1714 /* | |
| 1715 Same as adler32(), but with a size_t length. | |
| 1716 */ | |
| 1717 | |
| 1718 /* | |
| 1719 ZEXTERN uLong ZEXPORT adler32_combine(uLong adler1, uLong adler2, | |
| 1720 z_off_t len2); | |
| 1721 | |
| 1722 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 | |
| 1723 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for | |
| 1724 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of | |
| 1725 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note | |
| 1726 that the z_off_t type (like off_t) is a signed integer. If len2 is | |
| 1727 negative, the result has no meaning or utility. | |
| 1728 */ | |
| 1729 | |
| 1730 ZEXTERN uLong ZEXPORT crc32(uLong crc, const Bytef *buf, uInt len); | |
| 1731 /* | |
| 1732 Update a running CRC-32 with the bytes buf[0..len-1] and return the | |
| 1733 updated CRC-32. A CRC-32 value is in the range of a 32-bit unsigned integer. | |
| 1734 If buf is Z_NULL, this function returns the required initial value for the | |
| 1735 crc. Pre- and post-conditioning (one's complement) is performed within this | |
| 1736 function so it shouldn't be done by the application. | |
| 1737 | |
| 1738 Usage example: | |
| 1739 | |
| 1740 uLong crc = crc32(0L, Z_NULL, 0); | |
| 1741 | |
| 1742 while (read_buffer(buffer, length) != EOF) { | |
| 1743 crc = crc32(crc, buffer, length); | |
| 1744 } | |
| 1745 if (crc != original_crc) error(); | |
| 1746 */ | |
| 1747 | |
| 1748 ZEXTERN uLong ZEXPORT crc32_z(uLong crc, const Bytef *buf, | |
| 1749 z_size_t len); | |
| 1750 /* | |
| 1751 Same as crc32(), but with a size_t length. | |
| 1752 */ | |
| 1753 | |
| 1754 /* | |
| 1755 ZEXTERN uLong ZEXPORT crc32_combine(uLong crc1, uLong crc2, z_off_t len2); | |
| 1756 | |
| 1757 Combine two CRC-32 check values into one. For two sequences of bytes, | |
| 1758 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were | |
| 1759 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 | |
| 1760 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and | |
| 1761 len2. len2 must be non-negative. | |
| 1762 */ | |
| 1763 | |
| 1764 /* | |
| 1765 ZEXTERN uLong ZEXPORT crc32_combine_gen(z_off_t len2); | |
| 1766 | |
| 1767 Return the operator corresponding to length len2, to be used with | |
| 1768 crc32_combine_op(). len2 must be non-negative. | |
| 1769 */ | |
| 1770 | |
| 1771 ZEXTERN uLong ZEXPORT crc32_combine_op(uLong crc1, uLong crc2, uLong op); | |
| 1772 /* | |
| 1773 Give the same result as crc32_combine(), using op in place of len2. op is | |
| 1774 is generated from len2 by crc32_combine_gen(). This will be faster than | |
| 1775 crc32_combine() if the generated op is used more than once. | |
| 1776 */ | |
| 1777 | |
| 1778 | |
| 1779 /* various hacks, don't look :) */ | |
| 1780 | |
| 1781 /* deflateInit and inflateInit are macros to allow checking the zlib version | |
| 1782 * and the compiler's view of z_stream: | |
| 1783 */ | |
| 1784 ZEXTERN int ZEXPORT deflateInit_(z_streamp strm, int level, | |
| 1785 const char *version, int stream_size); | |
| 1786 ZEXTERN int ZEXPORT inflateInit_(z_streamp strm, | |
| 1787 const char *version, int stream_size); | |
| 1788 ZEXTERN int ZEXPORT deflateInit2_(z_streamp strm, int level, int method, | |
| 1789 int windowBits, int memLevel, | |
| 1790 int strategy, const char *version, | |
| 1791 int stream_size); | |
| 1792 ZEXTERN int ZEXPORT inflateInit2_(z_streamp strm, int windowBits, | |
| 1793 const char *version, int stream_size); | |
| 1794 ZEXTERN int ZEXPORT inflateBackInit_(z_streamp strm, int windowBits, | |
| 1795 unsigned char FAR *window, | |
| 1796 const char *version, | |
| 1797 int stream_size); | |
| 1798 #ifdef Z_PREFIX_SET | |
| 1799 # define z_deflateInit(strm, level) \ | |
| 1800 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) | |
| 1801 # define z_inflateInit(strm) \ | |
| 1802 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) | |
| 1803 # define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ | |
| 1804 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ | |
| 1805 (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) | |
| 1806 # define z_inflateInit2(strm, windowBits) \ | |
| 1807 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ | |
| 1808 (int)sizeof(z_stream)) | |
| 1809 # define z_inflateBackInit(strm, windowBits, window) \ | |
| 1810 inflateBackInit_((strm), (windowBits), (window), \ | |
| 1811 ZLIB_VERSION, (int)sizeof(z_stream)) | |
| 1812 #else | |
| 1813 # define deflateInit(strm, level) \ | |
| 1814 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) | |
| 1815 # define inflateInit(strm) \ | |
| 1816 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) | |
| 1817 # define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ | |
| 1818 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ | |
| 1819 (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) | |
| 1820 # define inflateInit2(strm, windowBits) \ | |
| 1821 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ | |
| 1822 (int)sizeof(z_stream)) | |
| 1823 # define inflateBackInit(strm, windowBits, window) \ | |
| 1824 inflateBackInit_((strm), (windowBits), (window), \ | |
| 1825 ZLIB_VERSION, (int)sizeof(z_stream)) | |
| 1826 #endif | |
| 1827 | |
| 1828 #ifndef Z_SOLO | |
| 1829 | |
| 1830 /* gzgetc() macro and its supporting function and exposed data structure. Note | |
| 1831 * that the real internal state is much larger than the exposed structure. | |
| 1832 * This abbreviated structure exposes just enough for the gzgetc() macro. The | |
| 1833 * user should not mess with these exposed elements, since their names or | |
| 1834 * behavior could change in the future, perhaps even capriciously. They can | |
| 1835 * only be used by the gzgetc() macro. You have been warned. | |
| 1836 */ | |
| 1837 struct gzFile_s { | |
| 1838 unsigned have; | |
| 1839 unsigned char *next; | |
| 1840 z_off64_t pos; | |
| 1841 }; | |
| 1842 ZEXTERN int ZEXPORT gzgetc_(gzFile file); /* backward compatibility */ | |
| 1843 #ifdef Z_PREFIX_SET | |
| 1844 # undef z_gzgetc | |
| 1845 # define z_gzgetc(g) \ | |
| 1846 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) | |
| 1847 #else | |
| 1848 # define gzgetc(g) \ | |
| 1849 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) | |
| 1850 #endif | |
| 1851 | |
| 1852 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or | |
| 1853 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if | |
| 1854 * both are true, the application gets the *64 functions, and the regular | |
| 1855 * functions are changed to 64 bits) -- in case these are set on systems | |
| 1856 * without large file support, _LFS64_LARGEFILE must also be true | |
| 1857 */ | |
| 1858 #ifdef Z_LARGE64 | |
| 1859 ZEXTERN gzFile ZEXPORT gzopen64(const char *, const char *); | |
| 1860 ZEXTERN z_off64_t ZEXPORT gzseek64(gzFile, z_off64_t, int); | |
| 1861 ZEXTERN z_off64_t ZEXPORT gztell64(gzFile); | |
| 1862 ZEXTERN z_off64_t ZEXPORT gzoffset64(gzFile); | |
| 1863 ZEXTERN uLong ZEXPORT adler32_combine64(uLong, uLong, z_off64_t); | |
| 1864 ZEXTERN uLong ZEXPORT crc32_combine64(uLong, uLong, z_off64_t); | |
| 1865 ZEXTERN uLong ZEXPORT crc32_combine_gen64(z_off64_t); | |
| 1866 #endif | |
| 1867 | |
| 1868 #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) | |
| 1869 # ifdef Z_PREFIX_SET | |
| 1870 # define z_gzopen z_gzopen64 | |
| 1871 # define z_gzseek z_gzseek64 | |
| 1872 # define z_gztell z_gztell64 | |
| 1873 # define z_gzoffset z_gzoffset64 | |
| 1874 # define z_adler32_combine z_adler32_combine64 | |
| 1875 # define z_crc32_combine z_crc32_combine64 | |
| 1876 # define z_crc32_combine_gen z_crc32_combine_gen64 | |
| 1877 # else | |
| 1878 # define gzopen gzopen64 | |
| 1879 # define gzseek gzseek64 | |
| 1880 # define gztell gztell64 | |
| 1881 # define gzoffset gzoffset64 | |
| 1882 # define adler32_combine adler32_combine64 | |
| 1883 # define crc32_combine crc32_combine64 | |
| 1884 # define crc32_combine_gen crc32_combine_gen64 | |
| 1885 # endif | |
| 1886 # ifndef Z_LARGE64 | |
| 1887 ZEXTERN gzFile ZEXPORT gzopen64(const char *, const char *); | |
| 1888 ZEXTERN z_off_t ZEXPORT gzseek64(gzFile, z_off_t, int); | |
| 1889 ZEXTERN z_off_t ZEXPORT gztell64(gzFile); | |
| 1890 ZEXTERN z_off_t ZEXPORT gzoffset64(gzFile); | |
| 1891 ZEXTERN uLong ZEXPORT adler32_combine64(uLong, uLong, z_off_t); | |
| 1892 ZEXTERN uLong ZEXPORT crc32_combine64(uLong, uLong, z_off_t); | |
| 1893 ZEXTERN uLong ZEXPORT crc32_combine_gen64(z_off_t); | |
| 1894 # endif | |
| 1895 #else | |
| 1896 ZEXTERN gzFile ZEXPORT gzopen(const char *, const char *); | |
| 1897 ZEXTERN z_off_t ZEXPORT gzseek(gzFile, z_off_t, int); | |
| 1898 ZEXTERN z_off_t ZEXPORT gztell(gzFile); | |
| 1899 ZEXTERN z_off_t ZEXPORT gzoffset(gzFile); | |
| 1900 ZEXTERN uLong ZEXPORT adler32_combine(uLong, uLong, z_off_t); | |
| 1901 ZEXTERN uLong ZEXPORT crc32_combine(uLong, uLong, z_off_t); | |
| 1902 ZEXTERN uLong ZEXPORT crc32_combine_gen(z_off_t); | |
| 1903 #endif | |
| 1904 | |
| 1905 #else /* Z_SOLO */ | |
| 1906 | |
| 1907 ZEXTERN uLong ZEXPORT adler32_combine(uLong, uLong, z_off_t); | |
| 1908 ZEXTERN uLong ZEXPORT crc32_combine(uLong, uLong, z_off_t); | |
| 1909 ZEXTERN uLong ZEXPORT crc32_combine_gen(z_off_t); | |
| 1910 | |
| 1911 #endif /* !Z_SOLO */ | |
| 1912 | |
| 1913 /* undocumented functions */ | |
| 1914 ZEXTERN const char * ZEXPORT zError(int); | |
| 1915 ZEXTERN int ZEXPORT inflateSyncPoint(z_streamp); | |
| 1916 ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table(void); | |
| 1917 ZEXTERN int ZEXPORT inflateUndermine(z_streamp, int); | |
| 1918 ZEXTERN int ZEXPORT inflateValidate(z_streamp, int); | |
| 1919 ZEXTERN unsigned long ZEXPORT inflateCodesUsed(z_streamp); | |
| 1920 ZEXTERN int ZEXPORT inflateResetKeep(z_streamp); | |
| 1921 ZEXTERN int ZEXPORT deflateResetKeep(z_streamp); | |
| 1922 #if defined(_WIN32) && !defined(Z_SOLO) | |
| 1923 ZEXTERN gzFile ZEXPORT gzopen_w(const wchar_t *path, | |
| 1924 const char *mode); | |
| 1925 #endif | |
| 1926 #if defined(STDC) || defined(Z_HAVE_STDARG_H) | |
| 1927 # ifndef Z_SOLO | |
| 1928 ZEXTERN int ZEXPORTVA gzvprintf(gzFile file, | |
| 1929 const char *format, | |
| 1930 va_list va); | |
| 1931 # endif | |
| 1932 #endif | |
| 1933 | |
| 1934 #ifdef __cplusplus | |
| 1935 } | |
| 1936 #endif | |
| 1937 | |
| 1938 #endif /* ZLIB_H */ |
