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Import GLPK 4.47
author Alpar Juttner <alpar@cs.elte.hu>
date Sun, 06 Nov 2011 20:59:10 +0100
parents
children
rev   line source
alpar@9 1 /* zlib.h -- interface of the 'zlib' general purpose compression library
alpar@9 2 version 1.2.5, April 19th, 2010
alpar@9 3
alpar@9 4 Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler
alpar@9 5
alpar@9 6 This software is provided 'as-is', without any express or implied
alpar@9 7 warranty. In no event will the authors be held liable for any damages
alpar@9 8 arising from the use of this software.
alpar@9 9
alpar@9 10 Permission is granted to anyone to use this software for any purpose,
alpar@9 11 including commercial applications, and to alter it and redistribute it
alpar@9 12 freely, subject to the following restrictions:
alpar@9 13
alpar@9 14 1. The origin of this software must not be misrepresented; you must not
alpar@9 15 claim that you wrote the original software. If you use this software
alpar@9 16 in a product, an acknowledgment in the product documentation would be
alpar@9 17 appreciated but is not required.
alpar@9 18 2. Altered source versions must be plainly marked as such, and must not be
alpar@9 19 misrepresented as being the original software.
alpar@9 20 3. This notice may not be removed or altered from any source distribution.
alpar@9 21
alpar@9 22 Jean-loup Gailly Mark Adler
alpar@9 23 jloup@gzip.org madler@alumni.caltech.edu
alpar@9 24
alpar@9 25
alpar@9 26 The data format used by the zlib library is described by RFCs (Request for
alpar@9 27 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
alpar@9 28 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
alpar@9 29 */
alpar@9 30
alpar@9 31 #ifndef ZLIB_H
alpar@9 32 #define ZLIB_H
alpar@9 33
alpar@9 34 #include "zconf.h"
alpar@9 35
alpar@9 36 #ifdef __cplusplus
alpar@9 37 extern "C" {
alpar@9 38 #endif
alpar@9 39
alpar@9 40 #define ZLIB_VERSION "1.2.5"
alpar@9 41 #define ZLIB_VERNUM 0x1250
alpar@9 42 #define ZLIB_VER_MAJOR 1
alpar@9 43 #define ZLIB_VER_MINOR 2
alpar@9 44 #define ZLIB_VER_REVISION 5
alpar@9 45 #define ZLIB_VER_SUBREVISION 0
alpar@9 46
alpar@9 47 /*
alpar@9 48 The 'zlib' compression library provides in-memory compression and
alpar@9 49 decompression functions, including integrity checks of the uncompressed data.
alpar@9 50 This version of the library supports only one compression method (deflation)
alpar@9 51 but other algorithms will be added later and will have the same stream
alpar@9 52 interface.
alpar@9 53
alpar@9 54 Compression can be done in a single step if the buffers are large enough,
alpar@9 55 or can be done by repeated calls of the compression function. In the latter
alpar@9 56 case, the application must provide more input and/or consume the output
alpar@9 57 (providing more output space) before each call.
alpar@9 58
alpar@9 59 The compressed data format used by default by the in-memory functions is
alpar@9 60 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
alpar@9 61 around a deflate stream, which is itself documented in RFC 1951.
alpar@9 62
alpar@9 63 The library also supports reading and writing files in gzip (.gz) format
alpar@9 64 with an interface similar to that of stdio using the functions that start
alpar@9 65 with "gz". The gzip format is different from the zlib format. gzip is a
alpar@9 66 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
alpar@9 67
alpar@9 68 This library can optionally read and write gzip streams in memory as well.
alpar@9 69
alpar@9 70 The zlib format was designed to be compact and fast for use in memory
alpar@9 71 and on communications channels. The gzip format was designed for single-
alpar@9 72 file compression on file systems, has a larger header than zlib to maintain
alpar@9 73 directory information, and uses a different, slower check method than zlib.
alpar@9 74
alpar@9 75 The library does not install any signal handler. The decoder checks
alpar@9 76 the consistency of the compressed data, so the library should never crash
alpar@9 77 even in case of corrupted input.
alpar@9 78 */
alpar@9 79
alpar@9 80 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
alpar@9 81 typedef void (*free_func) OF((voidpf opaque, voidpf address));
alpar@9 82
alpar@9 83 struct internal_state;
alpar@9 84
alpar@9 85 typedef struct z_stream_s {
alpar@9 86 Bytef *next_in; /* next input byte */
alpar@9 87 uInt avail_in; /* number of bytes available at next_in */
alpar@9 88 uLong total_in; /* total nb of input bytes read so far */
alpar@9 89
alpar@9 90 Bytef *next_out; /* next output byte should be put there */
alpar@9 91 uInt avail_out; /* remaining free space at next_out */
alpar@9 92 uLong total_out; /* total nb of bytes output so far */
alpar@9 93
alpar@9 94 char *msg; /* last error message, NULL if no error */
alpar@9 95 struct internal_state FAR *state; /* not visible by applications */
alpar@9 96
alpar@9 97 alloc_func zalloc; /* used to allocate the internal state */
alpar@9 98 free_func zfree; /* used to free the internal state */
alpar@9 99 voidpf opaque; /* private data object passed to zalloc and zfree */
alpar@9 100
alpar@9 101 int data_type; /* best guess about the data type: binary or text */
alpar@9 102 uLong adler; /* adler32 value of the uncompressed data */
alpar@9 103 uLong reserved; /* reserved for future use */
alpar@9 104 } z_stream;
alpar@9 105
alpar@9 106 typedef z_stream FAR *z_streamp;
alpar@9 107
alpar@9 108 /*
alpar@9 109 gzip header information passed to and from zlib routines. See RFC 1952
alpar@9 110 for more details on the meanings of these fields.
alpar@9 111 */
alpar@9 112 typedef struct gz_header_s {
alpar@9 113 int text; /* true if compressed data believed to be text */
alpar@9 114 uLong time; /* modification time */
alpar@9 115 int xflags; /* extra flags (not used when writing a gzip file) */
alpar@9 116 int os; /* operating system */
alpar@9 117 Bytef *extra; /* pointer to extra field or Z_NULL if none */
alpar@9 118 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
alpar@9 119 uInt extra_max; /* space at extra (only when reading header) */
alpar@9 120 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
alpar@9 121 uInt name_max; /* space at name (only when reading header) */
alpar@9 122 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
alpar@9 123 uInt comm_max; /* space at comment (only when reading header) */
alpar@9 124 int hcrc; /* true if there was or will be a header crc */
alpar@9 125 int done; /* true when done reading gzip header (not used
alpar@9 126 when writing a gzip file) */
alpar@9 127 } gz_header;
alpar@9 128
alpar@9 129 typedef gz_header FAR *gz_headerp;
alpar@9 130
alpar@9 131 /*
alpar@9 132 The application must update next_in and avail_in when avail_in has dropped
alpar@9 133 to zero. It must update next_out and avail_out when avail_out has dropped
alpar@9 134 to zero. The application must initialize zalloc, zfree and opaque before
alpar@9 135 calling the init function. All other fields are set by the compression
alpar@9 136 library and must not be updated by the application.
alpar@9 137
alpar@9 138 The opaque value provided by the application will be passed as the first
alpar@9 139 parameter for calls of zalloc and zfree. This can be useful for custom
alpar@9 140 memory management. The compression library attaches no meaning to the
alpar@9 141 opaque value.
alpar@9 142
alpar@9 143 zalloc must return Z_NULL if there is not enough memory for the object.
alpar@9 144 If zlib is used in a multi-threaded application, zalloc and zfree must be
alpar@9 145 thread safe.
alpar@9 146
alpar@9 147 On 16-bit systems, the functions zalloc and zfree must be able to allocate
alpar@9 148 exactly 65536 bytes, but will not be required to allocate more than this if
alpar@9 149 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
alpar@9 150 returned by zalloc for objects of exactly 65536 bytes *must* have their
alpar@9 151 offset normalized to zero. The default allocation function provided by this
alpar@9 152 library ensures this (see zutil.c). To reduce memory requirements and avoid
alpar@9 153 any allocation of 64K objects, at the expense of compression ratio, compile
alpar@9 154 the library with -DMAX_WBITS=14 (see zconf.h).
alpar@9 155
alpar@9 156 The fields total_in and total_out can be used for statistics or progress
alpar@9 157 reports. After compression, total_in holds the total size of the
alpar@9 158 uncompressed data and may be saved for use in the decompressor (particularly
alpar@9 159 if the decompressor wants to decompress everything in a single step).
alpar@9 160 */
alpar@9 161
alpar@9 162 /* constants */
alpar@9 163
alpar@9 164 #define Z_NO_FLUSH 0
alpar@9 165 #define Z_PARTIAL_FLUSH 1
alpar@9 166 #define Z_SYNC_FLUSH 2
alpar@9 167 #define Z_FULL_FLUSH 3
alpar@9 168 #define Z_FINISH 4
alpar@9 169 #define Z_BLOCK 5
alpar@9 170 #define Z_TREES 6
alpar@9 171 /* Allowed flush values; see deflate() and inflate() below for details */
alpar@9 172
alpar@9 173 #define Z_OK 0
alpar@9 174 #define Z_STREAM_END 1
alpar@9 175 #define Z_NEED_DICT 2
alpar@9 176 #define Z_ERRNO (-1)
alpar@9 177 #define Z_STREAM_ERROR (-2)
alpar@9 178 #define Z_DATA_ERROR (-3)
alpar@9 179 #define Z_MEM_ERROR (-4)
alpar@9 180 #define Z_BUF_ERROR (-5)
alpar@9 181 #define Z_VERSION_ERROR (-6)
alpar@9 182 /* Return codes for the compression/decompression functions. Negative values
alpar@9 183 * are errors, positive values are used for special but normal events.
alpar@9 184 */
alpar@9 185
alpar@9 186 #define Z_NO_COMPRESSION 0
alpar@9 187 #define Z_BEST_SPEED 1
alpar@9 188 #define Z_BEST_COMPRESSION 9
alpar@9 189 #define Z_DEFAULT_COMPRESSION (-1)
alpar@9 190 /* compression levels */
alpar@9 191
alpar@9 192 #define Z_FILTERED 1
alpar@9 193 #define Z_HUFFMAN_ONLY 2
alpar@9 194 #define Z_RLE 3
alpar@9 195 #define Z_FIXED 4
alpar@9 196 #define Z_DEFAULT_STRATEGY 0
alpar@9 197 /* compression strategy; see deflateInit2() below for details */
alpar@9 198
alpar@9 199 #define Z_BINARY 0
alpar@9 200 #define Z_TEXT 1
alpar@9 201 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
alpar@9 202 #define Z_UNKNOWN 2
alpar@9 203 /* Possible values of the data_type field (though see inflate()) */
alpar@9 204
alpar@9 205 #define Z_DEFLATED 8
alpar@9 206 /* The deflate compression method (the only one supported in this version) */
alpar@9 207
alpar@9 208 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
alpar@9 209
alpar@9 210 #define zlib_version zlibVersion()
alpar@9 211 /* for compatibility with versions < 1.0.2 */
alpar@9 212
alpar@9 213
alpar@9 214 /* basic functions */
alpar@9 215
alpar@9 216 ZEXTERN const char * ZEXPORT zlibVersion OF((void));
alpar@9 217 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
alpar@9 218 If the first character differs, the library code actually used is not
alpar@9 219 compatible with the zlib.h header file used by the application. This check
alpar@9 220 is automatically made by deflateInit and inflateInit.
alpar@9 221 */
alpar@9 222
alpar@9 223 /*
alpar@9 224 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
alpar@9 225
alpar@9 226 Initializes the internal stream state for compression. The fields
alpar@9 227 zalloc, zfree and opaque must be initialized before by the caller. If
alpar@9 228 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
alpar@9 229 allocation functions.
alpar@9 230
alpar@9 231 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
alpar@9 232 1 gives best speed, 9 gives best compression, 0 gives no compression at all
alpar@9 233 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
alpar@9 234 requests a default compromise between speed and compression (currently
alpar@9 235 equivalent to level 6).
alpar@9 236
alpar@9 237 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
alpar@9 238 memory, Z_STREAM_ERROR if level is not a valid compression level, or
alpar@9 239 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
alpar@9 240 with the version assumed by the caller (ZLIB_VERSION). msg is set to null
alpar@9 241 if there is no error message. deflateInit does not perform any compression:
alpar@9 242 this will be done by deflate().
alpar@9 243 */
alpar@9 244
alpar@9 245
alpar@9 246 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
alpar@9 247 /*
alpar@9 248 deflate compresses as much data as possible, and stops when the input
alpar@9 249 buffer becomes empty or the output buffer becomes full. It may introduce
alpar@9 250 some output latency (reading input without producing any output) except when
alpar@9 251 forced to flush.
alpar@9 252
alpar@9 253 The detailed semantics are as follows. deflate performs one or both of the
alpar@9 254 following actions:
alpar@9 255
alpar@9 256 - Compress more input starting at next_in and update next_in and avail_in
alpar@9 257 accordingly. If not all input can be processed (because there is not
alpar@9 258 enough room in the output buffer), next_in and avail_in are updated and
alpar@9 259 processing will resume at this point for the next call of deflate().
alpar@9 260
alpar@9 261 - Provide more output starting at next_out and update next_out and avail_out
alpar@9 262 accordingly. This action is forced if the parameter flush is non zero.
alpar@9 263 Forcing flush frequently degrades the compression ratio, so this parameter
alpar@9 264 should be set only when necessary (in interactive applications). Some
alpar@9 265 output may be provided even if flush is not set.
alpar@9 266
alpar@9 267 Before the call of deflate(), the application should ensure that at least
alpar@9 268 one of the actions is possible, by providing more input and/or consuming more
alpar@9 269 output, and updating avail_in or avail_out accordingly; avail_out should
alpar@9 270 never be zero before the call. The application can consume the compressed
alpar@9 271 output when it wants, for example when the output buffer is full (avail_out
alpar@9 272 == 0), or after each call of deflate(). If deflate returns Z_OK and with
alpar@9 273 zero avail_out, it must be called again after making room in the output
alpar@9 274 buffer because there might be more output pending.
alpar@9 275
alpar@9 276 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
alpar@9 277 decide how much data to accumulate before producing output, in order to
alpar@9 278 maximize compression.
alpar@9 279
alpar@9 280 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
alpar@9 281 flushed to the output buffer and the output is aligned on a byte boundary, so
alpar@9 282 that the decompressor can get all input data available so far. (In
alpar@9 283 particular avail_in is zero after the call if enough output space has been
alpar@9 284 provided before the call.) Flushing may degrade compression for some
alpar@9 285 compression algorithms and so it should be used only when necessary. This
alpar@9 286 completes the current deflate block and follows it with an empty stored block
alpar@9 287 that is three bits plus filler bits to the next byte, followed by four bytes
alpar@9 288 (00 00 ff ff).
alpar@9 289
alpar@9 290 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
alpar@9 291 output buffer, but the output is not aligned to a byte boundary. All of the
alpar@9 292 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
alpar@9 293 This completes the current deflate block and follows it with an empty fixed
alpar@9 294 codes block that is 10 bits long. This assures that enough bytes are output
alpar@9 295 in order for the decompressor to finish the block before the empty fixed code
alpar@9 296 block.
alpar@9 297
alpar@9 298 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
alpar@9 299 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
alpar@9 300 seven bits of the current block are held to be written as the next byte after
alpar@9 301 the next deflate block is completed. In this case, the decompressor may not
alpar@9 302 be provided enough bits at this point in order to complete decompression of
alpar@9 303 the data provided so far to the compressor. It may need to wait for the next
alpar@9 304 block to be emitted. This is for advanced applications that need to control
alpar@9 305 the emission of deflate blocks.
alpar@9 306
alpar@9 307 If flush is set to Z_FULL_FLUSH, all output is flushed as with
alpar@9 308 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
alpar@9 309 restart from this point if previous compressed data has been damaged or if
alpar@9 310 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
alpar@9 311 compression.
alpar@9 312
alpar@9 313 If deflate returns with avail_out == 0, this function must be called again
alpar@9 314 with the same value of the flush parameter and more output space (updated
alpar@9 315 avail_out), until the flush is complete (deflate returns with non-zero
alpar@9 316 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
alpar@9 317 avail_out is greater than six to avoid repeated flush markers due to
alpar@9 318 avail_out == 0 on return.
alpar@9 319
alpar@9 320 If the parameter flush is set to Z_FINISH, pending input is processed,
alpar@9 321 pending output is flushed and deflate returns with Z_STREAM_END if there was
alpar@9 322 enough output space; if deflate returns with Z_OK, this function must be
alpar@9 323 called again with Z_FINISH and more output space (updated avail_out) but no
alpar@9 324 more input data, until it returns with Z_STREAM_END or an error. After
alpar@9 325 deflate has returned Z_STREAM_END, the only possible operations on the stream
alpar@9 326 are deflateReset or deflateEnd.
alpar@9 327
alpar@9 328 Z_FINISH can be used immediately after deflateInit if all the compression
alpar@9 329 is to be done in a single step. In this case, avail_out must be at least the
alpar@9 330 value returned by deflateBound (see below). If deflate does not return
alpar@9 331 Z_STREAM_END, then it must be called again as described above.
alpar@9 332
alpar@9 333 deflate() sets strm->adler to the adler32 checksum of all input read
alpar@9 334 so far (that is, total_in bytes).
alpar@9 335
alpar@9 336 deflate() may update strm->data_type if it can make a good guess about
alpar@9 337 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
alpar@9 338 binary. This field is only for information purposes and does not affect the
alpar@9 339 compression algorithm in any manner.
alpar@9 340
alpar@9 341 deflate() returns Z_OK if some progress has been made (more input
alpar@9 342 processed or more output produced), Z_STREAM_END if all input has been
alpar@9 343 consumed and all output has been produced (only when flush is set to
alpar@9 344 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
alpar@9 345 if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
alpar@9 346 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
alpar@9 347 fatal, and deflate() can be called again with more input and more output
alpar@9 348 space to continue compressing.
alpar@9 349 */
alpar@9 350
alpar@9 351
alpar@9 352 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
alpar@9 353 /*
alpar@9 354 All dynamically allocated data structures for this stream are freed.
alpar@9 355 This function discards any unprocessed input and does not flush any pending
alpar@9 356 output.
alpar@9 357
alpar@9 358 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
alpar@9 359 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
alpar@9 360 prematurely (some input or output was discarded). In the error case, msg
alpar@9 361 may be set but then points to a static string (which must not be
alpar@9 362 deallocated).
alpar@9 363 */
alpar@9 364
alpar@9 365
alpar@9 366 /*
alpar@9 367 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
alpar@9 368
alpar@9 369 Initializes the internal stream state for decompression. The fields
alpar@9 370 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
alpar@9 371 the caller. If next_in is not Z_NULL and avail_in is large enough (the
alpar@9 372 exact value depends on the compression method), inflateInit determines the
alpar@9 373 compression method from the zlib header and allocates all data structures
alpar@9 374 accordingly; otherwise the allocation will be deferred to the first call of
alpar@9 375 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
alpar@9 376 use default allocation functions.
alpar@9 377
alpar@9 378 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
alpar@9 379 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
alpar@9 380 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
alpar@9 381 invalid, such as a null pointer to the structure. msg is set to null if
alpar@9 382 there is no error message. inflateInit does not perform any decompression
alpar@9 383 apart from possibly reading the zlib header if present: actual decompression
alpar@9 384 will be done by inflate(). (So next_in and avail_in may be modified, but
alpar@9 385 next_out and avail_out are unused and unchanged.) The current implementation
alpar@9 386 of inflateInit() does not process any header information -- that is deferred
alpar@9 387 until inflate() is called.
alpar@9 388 */
alpar@9 389
alpar@9 390
alpar@9 391 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
alpar@9 392 /*
alpar@9 393 inflate decompresses as much data as possible, and stops when the input
alpar@9 394 buffer becomes empty or the output buffer becomes full. It may introduce
alpar@9 395 some output latency (reading input without producing any output) except when
alpar@9 396 forced to flush.
alpar@9 397
alpar@9 398 The detailed semantics are as follows. inflate performs one or both of the
alpar@9 399 following actions:
alpar@9 400
alpar@9 401 - Decompress more input starting at next_in and update next_in and avail_in
alpar@9 402 accordingly. If not all input can be processed (because there is not
alpar@9 403 enough room in the output buffer), next_in is updated and processing will
alpar@9 404 resume at this point for the next call of inflate().
alpar@9 405
alpar@9 406 - Provide more output starting at next_out and update next_out and avail_out
alpar@9 407 accordingly. inflate() provides as much output as possible, until there is
alpar@9 408 no more input data or no more space in the output buffer (see below about
alpar@9 409 the flush parameter).
alpar@9 410
alpar@9 411 Before the call of inflate(), the application should ensure that at least
alpar@9 412 one of the actions is possible, by providing more input and/or consuming more
alpar@9 413 output, and updating the next_* and avail_* values accordingly. The
alpar@9 414 application can consume the uncompressed output when it wants, for example
alpar@9 415 when the output buffer is full (avail_out == 0), or after each call of
alpar@9 416 inflate(). If inflate returns Z_OK and with zero avail_out, it must be
alpar@9 417 called again after making room in the output buffer because there might be
alpar@9 418 more output pending.
alpar@9 419
alpar@9 420 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
alpar@9 421 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
alpar@9 422 output as possible to the output buffer. Z_BLOCK requests that inflate()
alpar@9 423 stop if and when it gets to the next deflate block boundary. When decoding
alpar@9 424 the zlib or gzip format, this will cause inflate() to return immediately
alpar@9 425 after the header and before the first block. When doing a raw inflate,
alpar@9 426 inflate() will go ahead and process the first block, and will return when it
alpar@9 427 gets to the end of that block, or when it runs out of data.
alpar@9 428
alpar@9 429 The Z_BLOCK option assists in appending to or combining deflate streams.
alpar@9 430 Also to assist in this, on return inflate() will set strm->data_type to the
alpar@9 431 number of unused bits in the last byte taken from strm->next_in, plus 64 if
alpar@9 432 inflate() is currently decoding the last block in the deflate stream, plus
alpar@9 433 128 if inflate() returned immediately after decoding an end-of-block code or
alpar@9 434 decoding the complete header up to just before the first byte of the deflate
alpar@9 435 stream. The end-of-block will not be indicated until all of the uncompressed
alpar@9 436 data from that block has been written to strm->next_out. The number of
alpar@9 437 unused bits may in general be greater than seven, except when bit 7 of
alpar@9 438 data_type is set, in which case the number of unused bits will be less than
alpar@9 439 eight. data_type is set as noted here every time inflate() returns for all
alpar@9 440 flush options, and so can be used to determine the amount of currently
alpar@9 441 consumed input in bits.
alpar@9 442
alpar@9 443 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
alpar@9 444 end of each deflate block header is reached, before any actual data in that
alpar@9 445 block is decoded. This allows the caller to determine the length of the
alpar@9 446 deflate block header for later use in random access within a deflate block.
alpar@9 447 256 is added to the value of strm->data_type when inflate() returns
alpar@9 448 immediately after reaching the end of the deflate block header.
alpar@9 449
alpar@9 450 inflate() should normally be called until it returns Z_STREAM_END or an
alpar@9 451 error. However if all decompression is to be performed in a single step (a
alpar@9 452 single call of inflate), the parameter flush should be set to Z_FINISH. In
alpar@9 453 this case all pending input is processed and all pending output is flushed;
alpar@9 454 avail_out must be large enough to hold all the uncompressed data. (The size
alpar@9 455 of the uncompressed data may have been saved by the compressor for this
alpar@9 456 purpose.) The next operation on this stream must be inflateEnd to deallocate
alpar@9 457 the decompression state. The use of Z_FINISH is never required, but can be
alpar@9 458 used to inform inflate that a faster approach may be used for the single
alpar@9 459 inflate() call.
alpar@9 460
alpar@9 461 In this implementation, inflate() always flushes as much output as
alpar@9 462 possible to the output buffer, and always uses the faster approach on the
alpar@9 463 first call. So the only effect of the flush parameter in this implementation
alpar@9 464 is on the return value of inflate(), as noted below, or when it returns early
alpar@9 465 because Z_BLOCK or Z_TREES is used.
alpar@9 466
alpar@9 467 If a preset dictionary is needed after this call (see inflateSetDictionary
alpar@9 468 below), inflate sets strm->adler to the adler32 checksum of the dictionary
alpar@9 469 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
alpar@9 470 strm->adler to the adler32 checksum of all output produced so far (that is,
alpar@9 471 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
alpar@9 472 below. At the end of the stream, inflate() checks that its computed adler32
alpar@9 473 checksum is equal to that saved by the compressor and returns Z_STREAM_END
alpar@9 474 only if the checksum is correct.
alpar@9 475
alpar@9 476 inflate() can decompress and check either zlib-wrapped or gzip-wrapped
alpar@9 477 deflate data. The header type is detected automatically, if requested when
alpar@9 478 initializing with inflateInit2(). Any information contained in the gzip
alpar@9 479 header is not retained, so applications that need that information should
alpar@9 480 instead use raw inflate, see inflateInit2() below, or inflateBack() and
alpar@9 481 perform their own processing of the gzip header and trailer.
alpar@9 482
alpar@9 483 inflate() returns Z_OK if some progress has been made (more input processed
alpar@9 484 or more output produced), Z_STREAM_END if the end of the compressed data has
alpar@9 485 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
alpar@9 486 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
alpar@9 487 corrupted (input stream not conforming to the zlib format or incorrect check
alpar@9 488 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
alpar@9 489 next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
alpar@9 490 Z_BUF_ERROR if no progress is possible or if there was not enough room in the
alpar@9 491 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
alpar@9 492 inflate() can be called again with more input and more output space to
alpar@9 493 continue decompressing. If Z_DATA_ERROR is returned, the application may
alpar@9 494 then call inflateSync() to look for a good compression block if a partial
alpar@9 495 recovery of the data is desired.
alpar@9 496 */
alpar@9 497
alpar@9 498
alpar@9 499 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
alpar@9 500 /*
alpar@9 501 All dynamically allocated data structures for this stream are freed.
alpar@9 502 This function discards any unprocessed input and does not flush any pending
alpar@9 503 output.
alpar@9 504
alpar@9 505 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
alpar@9 506 was inconsistent. In the error case, msg may be set but then points to a
alpar@9 507 static string (which must not be deallocated).
alpar@9 508 */
alpar@9 509
alpar@9 510
alpar@9 511 /* Advanced functions */
alpar@9 512
alpar@9 513 /*
alpar@9 514 The following functions are needed only in some special applications.
alpar@9 515 */
alpar@9 516
alpar@9 517 /*
alpar@9 518 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
alpar@9 519 int level,
alpar@9 520 int method,
alpar@9 521 int windowBits,
alpar@9 522 int memLevel,
alpar@9 523 int strategy));
alpar@9 524
alpar@9 525 This is another version of deflateInit with more compression options. The
alpar@9 526 fields next_in, zalloc, zfree and opaque must be initialized before by the
alpar@9 527 caller.
alpar@9 528
alpar@9 529 The method parameter is the compression method. It must be Z_DEFLATED in
alpar@9 530 this version of the library.
alpar@9 531
alpar@9 532 The windowBits parameter is the base two logarithm of the window size
alpar@9 533 (the size of the history buffer). It should be in the range 8..15 for this
alpar@9 534 version of the library. Larger values of this parameter result in better
alpar@9 535 compression at the expense of memory usage. The default value is 15 if
alpar@9 536 deflateInit is used instead.
alpar@9 537
alpar@9 538 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
alpar@9 539 determines the window size. deflate() will then generate raw deflate data
alpar@9 540 with no zlib header or trailer, and will not compute an adler32 check value.
alpar@9 541
alpar@9 542 windowBits can also be greater than 15 for optional gzip encoding. Add
alpar@9 543 16 to windowBits to write a simple gzip header and trailer around the
alpar@9 544 compressed data instead of a zlib wrapper. The gzip header will have no
alpar@9 545 file name, no extra data, no comment, no modification time (set to zero), no
alpar@9 546 header crc, and the operating system will be set to 255 (unknown). If a
alpar@9 547 gzip stream is being written, strm->adler is a crc32 instead of an adler32.
alpar@9 548
alpar@9 549 The memLevel parameter specifies how much memory should be allocated
alpar@9 550 for the internal compression state. memLevel=1 uses minimum memory but is
alpar@9 551 slow and reduces compression ratio; memLevel=9 uses maximum memory for
alpar@9 552 optimal speed. The default value is 8. See zconf.h for total memory usage
alpar@9 553 as a function of windowBits and memLevel.
alpar@9 554
alpar@9 555 The strategy parameter is used to tune the compression algorithm. Use the
alpar@9 556 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
alpar@9 557 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
alpar@9 558 string match), or Z_RLE to limit match distances to one (run-length
alpar@9 559 encoding). Filtered data consists mostly of small values with a somewhat
alpar@9 560 random distribution. In this case, the compression algorithm is tuned to
alpar@9 561 compress them better. The effect of Z_FILTERED is to force more Huffman
alpar@9 562 coding and less string matching; it is somewhat intermediate between
alpar@9 563 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
alpar@9 564 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
alpar@9 565 strategy parameter only affects the compression ratio but not the
alpar@9 566 correctness of the compressed output even if it is not set appropriately.
alpar@9 567 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
alpar@9 568 decoder for special applications.
alpar@9 569
alpar@9 570 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
alpar@9 571 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
alpar@9 572 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
alpar@9 573 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
alpar@9 574 set to null if there is no error message. deflateInit2 does not perform any
alpar@9 575 compression: this will be done by deflate().
alpar@9 576 */
alpar@9 577
alpar@9 578 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
alpar@9 579 const Bytef *dictionary,
alpar@9 580 uInt dictLength));
alpar@9 581 /*
alpar@9 582 Initializes the compression dictionary from the given byte sequence
alpar@9 583 without producing any compressed output. This function must be called
alpar@9 584 immediately after deflateInit, deflateInit2 or deflateReset, before any call
alpar@9 585 of deflate. The compressor and decompressor must use exactly the same
alpar@9 586 dictionary (see inflateSetDictionary).
alpar@9 587
alpar@9 588 The dictionary should consist of strings (byte sequences) that are likely
alpar@9 589 to be encountered later in the data to be compressed, with the most commonly
alpar@9 590 used strings preferably put towards the end of the dictionary. Using a
alpar@9 591 dictionary is most useful when the data to be compressed is short and can be
alpar@9 592 predicted with good accuracy; the data can then be compressed better than
alpar@9 593 with the default empty dictionary.
alpar@9 594
alpar@9 595 Depending on the size of the compression data structures selected by
alpar@9 596 deflateInit or deflateInit2, a part of the dictionary may in effect be
alpar@9 597 discarded, for example if the dictionary is larger than the window size
alpar@9 598 provided in deflateInit or deflateInit2. Thus the strings most likely to be
alpar@9 599 useful should be put at the end of the dictionary, not at the front. In
alpar@9 600 addition, the current implementation of deflate will use at most the window
alpar@9 601 size minus 262 bytes of the provided dictionary.
alpar@9 602
alpar@9 603 Upon return of this function, strm->adler is set to the adler32 value
alpar@9 604 of the dictionary; the decompressor may later use this value to determine
alpar@9 605 which dictionary has been used by the compressor. (The adler32 value
alpar@9 606 applies to the whole dictionary even if only a subset of the dictionary is
alpar@9 607 actually used by the compressor.) If a raw deflate was requested, then the
alpar@9 608 adler32 value is not computed and strm->adler is not set.
alpar@9 609
alpar@9 610 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
alpar@9 611 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
alpar@9 612 inconsistent (for example if deflate has already been called for this stream
alpar@9 613 or if the compression method is bsort). deflateSetDictionary does not
alpar@9 614 perform any compression: this will be done by deflate().
alpar@9 615 */
alpar@9 616
alpar@9 617 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
alpar@9 618 z_streamp source));
alpar@9 619 /*
alpar@9 620 Sets the destination stream as a complete copy of the source stream.
alpar@9 621
alpar@9 622 This function can be useful when several compression strategies will be
alpar@9 623 tried, for example when there are several ways of pre-processing the input
alpar@9 624 data with a filter. The streams that will be discarded should then be freed
alpar@9 625 by calling deflateEnd. Note that deflateCopy duplicates the internal
alpar@9 626 compression state which can be quite large, so this strategy is slow and can
alpar@9 627 consume lots of memory.
alpar@9 628
alpar@9 629 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
alpar@9 630 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
alpar@9 631 (such as zalloc being Z_NULL). msg is left unchanged in both source and
alpar@9 632 destination.
alpar@9 633 */
alpar@9 634
alpar@9 635 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
alpar@9 636 /*
alpar@9 637 This function is equivalent to deflateEnd followed by deflateInit,
alpar@9 638 but does not free and reallocate all the internal compression state. The
alpar@9 639 stream will keep the same compression level and any other attributes that
alpar@9 640 may have been set by deflateInit2.
alpar@9 641
alpar@9 642 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
alpar@9 643 stream state was inconsistent (such as zalloc or state being Z_NULL).
alpar@9 644 */
alpar@9 645
alpar@9 646 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
alpar@9 647 int level,
alpar@9 648 int strategy));
alpar@9 649 /*
alpar@9 650 Dynamically update the compression level and compression strategy. The
alpar@9 651 interpretation of level and strategy is as in deflateInit2. This can be
alpar@9 652 used to switch between compression and straight copy of the input data, or
alpar@9 653 to switch to a different kind of input data requiring a different strategy.
alpar@9 654 If the compression level is changed, the input available so far is
alpar@9 655 compressed with the old level (and may be flushed); the new level will take
alpar@9 656 effect only at the next call of deflate().
alpar@9 657
alpar@9 658 Before the call of deflateParams, the stream state must be set as for
alpar@9 659 a call of deflate(), since the currently available input may have to be
alpar@9 660 compressed and flushed. In particular, strm->avail_out must be non-zero.
alpar@9 661
alpar@9 662 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
alpar@9 663 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
alpar@9 664 strm->avail_out was zero.
alpar@9 665 */
alpar@9 666
alpar@9 667 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
alpar@9 668 int good_length,
alpar@9 669 int max_lazy,
alpar@9 670 int nice_length,
alpar@9 671 int max_chain));
alpar@9 672 /*
alpar@9 673 Fine tune deflate's internal compression parameters. This should only be
alpar@9 674 used by someone who understands the algorithm used by zlib's deflate for
alpar@9 675 searching for the best matching string, and even then only by the most
alpar@9 676 fanatic optimizer trying to squeeze out the last compressed bit for their
alpar@9 677 specific input data. Read the deflate.c source code for the meaning of the
alpar@9 678 max_lazy, good_length, nice_length, and max_chain parameters.
alpar@9 679
alpar@9 680 deflateTune() can be called after deflateInit() or deflateInit2(), and
alpar@9 681 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
alpar@9 682 */
alpar@9 683
alpar@9 684 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
alpar@9 685 uLong sourceLen));
alpar@9 686 /*
alpar@9 687 deflateBound() returns an upper bound on the compressed size after
alpar@9 688 deflation of sourceLen bytes. It must be called after deflateInit() or
alpar@9 689 deflateInit2(), and after deflateSetHeader(), if used. This would be used
alpar@9 690 to allocate an output buffer for deflation in a single pass, and so would be
alpar@9 691 called before deflate().
alpar@9 692 */
alpar@9 693
alpar@9 694 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
alpar@9 695 int bits,
alpar@9 696 int value));
alpar@9 697 /*
alpar@9 698 deflatePrime() inserts bits in the deflate output stream. The intent
alpar@9 699 is that this function is used to start off the deflate output with the bits
alpar@9 700 leftover from a previous deflate stream when appending to it. As such, this
alpar@9 701 function can only be used for raw deflate, and must be used before the first
alpar@9 702 deflate() call after a deflateInit2() or deflateReset(). bits must be less
alpar@9 703 than or equal to 16, and that many of the least significant bits of value
alpar@9 704 will be inserted in the output.
alpar@9 705
alpar@9 706 deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
alpar@9 707 stream state was inconsistent.
alpar@9 708 */
alpar@9 709
alpar@9 710 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
alpar@9 711 gz_headerp head));
alpar@9 712 /*
alpar@9 713 deflateSetHeader() provides gzip header information for when a gzip
alpar@9 714 stream is requested by deflateInit2(). deflateSetHeader() may be called
alpar@9 715 after deflateInit2() or deflateReset() and before the first call of
alpar@9 716 deflate(). The text, time, os, extra field, name, and comment information
alpar@9 717 in the provided gz_header structure are written to the gzip header (xflag is
alpar@9 718 ignored -- the extra flags are set according to the compression level). The
alpar@9 719 caller must assure that, if not Z_NULL, name and comment are terminated with
alpar@9 720 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
alpar@9 721 available there. If hcrc is true, a gzip header crc is included. Note that
alpar@9 722 the current versions of the command-line version of gzip (up through version
alpar@9 723 1.3.x) do not support header crc's, and will report that it is a "multi-part
alpar@9 724 gzip file" and give up.
alpar@9 725
alpar@9 726 If deflateSetHeader is not used, the default gzip header has text false,
alpar@9 727 the time set to zero, and os set to 255, with no extra, name, or comment
alpar@9 728 fields. The gzip header is returned to the default state by deflateReset().
alpar@9 729
alpar@9 730 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
alpar@9 731 stream state was inconsistent.
alpar@9 732 */
alpar@9 733
alpar@9 734 /*
alpar@9 735 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
alpar@9 736 int windowBits));
alpar@9 737
alpar@9 738 This is another version of inflateInit with an extra parameter. The
alpar@9 739 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
alpar@9 740 before by the caller.
alpar@9 741
alpar@9 742 The windowBits parameter is the base two logarithm of the maximum window
alpar@9 743 size (the size of the history buffer). It should be in the range 8..15 for
alpar@9 744 this version of the library. The default value is 15 if inflateInit is used
alpar@9 745 instead. windowBits must be greater than or equal to the windowBits value
alpar@9 746 provided to deflateInit2() while compressing, or it must be equal to 15 if
alpar@9 747 deflateInit2() was not used. If a compressed stream with a larger window
alpar@9 748 size is given as input, inflate() will return with the error code
alpar@9 749 Z_DATA_ERROR instead of trying to allocate a larger window.
alpar@9 750
alpar@9 751 windowBits can also be zero to request that inflate use the window size in
alpar@9 752 the zlib header of the compressed stream.
alpar@9 753
alpar@9 754 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
alpar@9 755 determines the window size. inflate() will then process raw deflate data,
alpar@9 756 not looking for a zlib or gzip header, not generating a check value, and not
alpar@9 757 looking for any check values for comparison at the end of the stream. This
alpar@9 758 is for use with other formats that use the deflate compressed data format
alpar@9 759 such as zip. Those formats provide their own check values. If a custom
alpar@9 760 format is developed using the raw deflate format for compressed data, it is
alpar@9 761 recommended that a check value such as an adler32 or a crc32 be applied to
alpar@9 762 the uncompressed data as is done in the zlib, gzip, and zip formats. For
alpar@9 763 most applications, the zlib format should be used as is. Note that comments
alpar@9 764 above on the use in deflateInit2() applies to the magnitude of windowBits.
alpar@9 765
alpar@9 766 windowBits can also be greater than 15 for optional gzip decoding. Add
alpar@9 767 32 to windowBits to enable zlib and gzip decoding with automatic header
alpar@9 768 detection, or add 16 to decode only the gzip format (the zlib format will
alpar@9 769 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
alpar@9 770 crc32 instead of an adler32.
alpar@9 771
alpar@9 772 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
alpar@9 773 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
alpar@9 774 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
alpar@9 775 invalid, such as a null pointer to the structure. msg is set to null if
alpar@9 776 there is no error message. inflateInit2 does not perform any decompression
alpar@9 777 apart from possibly reading the zlib header if present: actual decompression
alpar@9 778 will be done by inflate(). (So next_in and avail_in may be modified, but
alpar@9 779 next_out and avail_out are unused and unchanged.) The current implementation
alpar@9 780 of inflateInit2() does not process any header information -- that is
alpar@9 781 deferred until inflate() is called.
alpar@9 782 */
alpar@9 783
alpar@9 784 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
alpar@9 785 const Bytef *dictionary,
alpar@9 786 uInt dictLength));
alpar@9 787 /*
alpar@9 788 Initializes the decompression dictionary from the given uncompressed byte
alpar@9 789 sequence. This function must be called immediately after a call of inflate,
alpar@9 790 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
alpar@9 791 can be determined from the adler32 value returned by that call of inflate.
alpar@9 792 The compressor and decompressor must use exactly the same dictionary (see
alpar@9 793 deflateSetDictionary). For raw inflate, this function can be called
alpar@9 794 immediately after inflateInit2() or inflateReset() and before any call of
alpar@9 795 inflate() to set the dictionary. The application must insure that the
alpar@9 796 dictionary that was used for compression is provided.
alpar@9 797
alpar@9 798 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
alpar@9 799 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
alpar@9 800 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
alpar@9 801 expected one (incorrect adler32 value). inflateSetDictionary does not
alpar@9 802 perform any decompression: this will be done by subsequent calls of
alpar@9 803 inflate().
alpar@9 804 */
alpar@9 805
alpar@9 806 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
alpar@9 807 /*
alpar@9 808 Skips invalid compressed data until a full flush point (see above the
alpar@9 809 description of deflate with Z_FULL_FLUSH) can be found, or until all
alpar@9 810 available input is skipped. No output is provided.
alpar@9 811
alpar@9 812 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
alpar@9 813 if no more input was provided, Z_DATA_ERROR if no flush point has been
alpar@9 814 found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the
alpar@9 815 success case, the application may save the current current value of total_in
alpar@9 816 which indicates where valid compressed data was found. In the error case,
alpar@9 817 the application may repeatedly call inflateSync, providing more input each
alpar@9 818 time, until success or end of the input data.
alpar@9 819 */
alpar@9 820
alpar@9 821 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
alpar@9 822 z_streamp source));
alpar@9 823 /*
alpar@9 824 Sets the destination stream as a complete copy of the source stream.
alpar@9 825
alpar@9 826 This function can be useful when randomly accessing a large stream. The
alpar@9 827 first pass through the stream can periodically record the inflate state,
alpar@9 828 allowing restarting inflate at those points when randomly accessing the
alpar@9 829 stream.
alpar@9 830
alpar@9 831 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
alpar@9 832 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
alpar@9 833 (such as zalloc being Z_NULL). msg is left unchanged in both source and
alpar@9 834 destination.
alpar@9 835 */
alpar@9 836
alpar@9 837 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
alpar@9 838 /*
alpar@9 839 This function is equivalent to inflateEnd followed by inflateInit,
alpar@9 840 but does not free and reallocate all the internal decompression state. The
alpar@9 841 stream will keep attributes that may have been set by inflateInit2.
alpar@9 842
alpar@9 843 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
alpar@9 844 stream state was inconsistent (such as zalloc or state being Z_NULL).
alpar@9 845 */
alpar@9 846
alpar@9 847 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
alpar@9 848 int windowBits));
alpar@9 849 /*
alpar@9 850 This function is the same as inflateReset, but it also permits changing
alpar@9 851 the wrap and window size requests. The windowBits parameter is interpreted
alpar@9 852 the same as it is for inflateInit2.
alpar@9 853
alpar@9 854 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
alpar@9 855 stream state was inconsistent (such as zalloc or state being Z_NULL), or if
alpar@9 856 the windowBits parameter is invalid.
alpar@9 857 */
alpar@9 858
alpar@9 859 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
alpar@9 860 int bits,
alpar@9 861 int value));
alpar@9 862 /*
alpar@9 863 This function inserts bits in the inflate input stream. The intent is
alpar@9 864 that this function is used to start inflating at a bit position in the
alpar@9 865 middle of a byte. The provided bits will be used before any bytes are used
alpar@9 866 from next_in. This function should only be used with raw inflate, and
alpar@9 867 should be used before the first inflate() call after inflateInit2() or
alpar@9 868 inflateReset(). bits must be less than or equal to 16, and that many of the
alpar@9 869 least significant bits of value will be inserted in the input.
alpar@9 870
alpar@9 871 If bits is negative, then the input stream bit buffer is emptied. Then
alpar@9 872 inflatePrime() can be called again to put bits in the buffer. This is used
alpar@9 873 to clear out bits leftover after feeding inflate a block description prior
alpar@9 874 to feeding inflate codes.
alpar@9 875
alpar@9 876 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
alpar@9 877 stream state was inconsistent.
alpar@9 878 */
alpar@9 879
alpar@9 880 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
alpar@9 881 /*
alpar@9 882 This function returns two values, one in the lower 16 bits of the return
alpar@9 883 value, and the other in the remaining upper bits, obtained by shifting the
alpar@9 884 return value down 16 bits. If the upper value is -1 and the lower value is
alpar@9 885 zero, then inflate() is currently decoding information outside of a block.
alpar@9 886 If the upper value is -1 and the lower value is non-zero, then inflate is in
alpar@9 887 the middle of a stored block, with the lower value equaling the number of
alpar@9 888 bytes from the input remaining to copy. If the upper value is not -1, then
alpar@9 889 it is the number of bits back from the current bit position in the input of
alpar@9 890 the code (literal or length/distance pair) currently being processed. In
alpar@9 891 that case the lower value is the number of bytes already emitted for that
alpar@9 892 code.
alpar@9 893
alpar@9 894 A code is being processed if inflate is waiting for more input to complete
alpar@9 895 decoding of the code, or if it has completed decoding but is waiting for
alpar@9 896 more output space to write the literal or match data.
alpar@9 897
alpar@9 898 inflateMark() is used to mark locations in the input data for random
alpar@9 899 access, which may be at bit positions, and to note those cases where the
alpar@9 900 output of a code may span boundaries of random access blocks. The current
alpar@9 901 location in the input stream can be determined from avail_in and data_type
alpar@9 902 as noted in the description for the Z_BLOCK flush parameter for inflate.
alpar@9 903
alpar@9 904 inflateMark returns the value noted above or -1 << 16 if the provided
alpar@9 905 source stream state was inconsistent.
alpar@9 906 */
alpar@9 907
alpar@9 908 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
alpar@9 909 gz_headerp head));
alpar@9 910 /*
alpar@9 911 inflateGetHeader() requests that gzip header information be stored in the
alpar@9 912 provided gz_header structure. inflateGetHeader() may be called after
alpar@9 913 inflateInit2() or inflateReset(), and before the first call of inflate().
alpar@9 914 As inflate() processes the gzip stream, head->done is zero until the header
alpar@9 915 is completed, at which time head->done is set to one. If a zlib stream is
alpar@9 916 being decoded, then head->done is set to -1 to indicate that there will be
alpar@9 917 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
alpar@9 918 used to force inflate() to return immediately after header processing is
alpar@9 919 complete and before any actual data is decompressed.
alpar@9 920
alpar@9 921 The text, time, xflags, and os fields are filled in with the gzip header
alpar@9 922 contents. hcrc is set to true if there is a header CRC. (The header CRC
alpar@9 923 was valid if done is set to one.) If extra is not Z_NULL, then extra_max
alpar@9 924 contains the maximum number of bytes to write to extra. Once done is true,
alpar@9 925 extra_len contains the actual extra field length, and extra contains the
alpar@9 926 extra field, or that field truncated if extra_max is less than extra_len.
alpar@9 927 If name is not Z_NULL, then up to name_max characters are written there,
alpar@9 928 terminated with a zero unless the length is greater than name_max. If
alpar@9 929 comment is not Z_NULL, then up to comm_max characters are written there,
alpar@9 930 terminated with a zero unless the length is greater than comm_max. When any
alpar@9 931 of extra, name, or comment are not Z_NULL and the respective field is not
alpar@9 932 present in the header, then that field is set to Z_NULL to signal its
alpar@9 933 absence. This allows the use of deflateSetHeader() with the returned
alpar@9 934 structure to duplicate the header. However if those fields are set to
alpar@9 935 allocated memory, then the application will need to save those pointers
alpar@9 936 elsewhere so that they can be eventually freed.
alpar@9 937
alpar@9 938 If inflateGetHeader is not used, then the header information is simply
alpar@9 939 discarded. The header is always checked for validity, including the header
alpar@9 940 CRC if present. inflateReset() will reset the process to discard the header
alpar@9 941 information. The application would need to call inflateGetHeader() again to
alpar@9 942 retrieve the header from the next gzip stream.
alpar@9 943
alpar@9 944 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
alpar@9 945 stream state was inconsistent.
alpar@9 946 */
alpar@9 947
alpar@9 948 /*
alpar@9 949 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
alpar@9 950 unsigned char FAR *window));
alpar@9 951
alpar@9 952 Initialize the internal stream state for decompression using inflateBack()
alpar@9 953 calls. The fields zalloc, zfree and opaque in strm must be initialized
alpar@9 954 before the call. If zalloc and zfree are Z_NULL, then the default library-
alpar@9 955 derived memory allocation routines are used. windowBits is the base two
alpar@9 956 logarithm of the window size, in the range 8..15. window is a caller
alpar@9 957 supplied buffer of that size. Except for special applications where it is
alpar@9 958 assured that deflate was used with small window sizes, windowBits must be 15
alpar@9 959 and a 32K byte window must be supplied to be able to decompress general
alpar@9 960 deflate streams.
alpar@9 961
alpar@9 962 See inflateBack() for the usage of these routines.
alpar@9 963
alpar@9 964 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
alpar@9 965 the paramaters are invalid, Z_MEM_ERROR if the internal state could not be
alpar@9 966 allocated, or Z_VERSION_ERROR if the version of the library does not match
alpar@9 967 the version of the header file.
alpar@9 968 */
alpar@9 969
alpar@9 970 typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
alpar@9 971 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
alpar@9 972
alpar@9 973 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
alpar@9 974 in_func in, void FAR *in_desc,
alpar@9 975 out_func out, void FAR *out_desc));
alpar@9 976 /*
alpar@9 977 inflateBack() does a raw inflate with a single call using a call-back
alpar@9 978 interface for input and output. This is more efficient than inflate() for
alpar@9 979 file i/o applications in that it avoids copying between the output and the
alpar@9 980 sliding window by simply making the window itself the output buffer. This
alpar@9 981 function trusts the application to not change the output buffer passed by
alpar@9 982 the output function, at least until inflateBack() returns.
alpar@9 983
alpar@9 984 inflateBackInit() must be called first to allocate the internal state
alpar@9 985 and to initialize the state with the user-provided window buffer.
alpar@9 986 inflateBack() may then be used multiple times to inflate a complete, raw
alpar@9 987 deflate stream with each call. inflateBackEnd() is then called to free the
alpar@9 988 allocated state.
alpar@9 989
alpar@9 990 A raw deflate stream is one with no zlib or gzip header or trailer.
alpar@9 991 This routine would normally be used in a utility that reads zip or gzip
alpar@9 992 files and writes out uncompressed files. The utility would decode the
alpar@9 993 header and process the trailer on its own, hence this routine expects only
alpar@9 994 the raw deflate stream to decompress. This is different from the normal
alpar@9 995 behavior of inflate(), which expects either a zlib or gzip header and
alpar@9 996 trailer around the deflate stream.
alpar@9 997
alpar@9 998 inflateBack() uses two subroutines supplied by the caller that are then
alpar@9 999 called by inflateBack() for input and output. inflateBack() calls those
alpar@9 1000 routines until it reads a complete deflate stream and writes out all of the
alpar@9 1001 uncompressed data, or until it encounters an error. The function's
alpar@9 1002 parameters and return types are defined above in the in_func and out_func
alpar@9 1003 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
alpar@9 1004 number of bytes of provided input, and a pointer to that input in buf. If
alpar@9 1005 there is no input available, in() must return zero--buf is ignored in that
alpar@9 1006 case--and inflateBack() will return a buffer error. inflateBack() will call
alpar@9 1007 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
alpar@9 1008 should return zero on success, or non-zero on failure. If out() returns
alpar@9 1009 non-zero, inflateBack() will return with an error. Neither in() nor out()
alpar@9 1010 are permitted to change the contents of the window provided to
alpar@9 1011 inflateBackInit(), which is also the buffer that out() uses to write from.
alpar@9 1012 The length written by out() will be at most the window size. Any non-zero
alpar@9 1013 amount of input may be provided by in().
alpar@9 1014
alpar@9 1015 For convenience, inflateBack() can be provided input on the first call by
alpar@9 1016 setting strm->next_in and strm->avail_in. If that input is exhausted, then
alpar@9 1017 in() will be called. Therefore strm->next_in must be initialized before
alpar@9 1018 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
alpar@9 1019 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
alpar@9 1020 must also be initialized, and then if strm->avail_in is not zero, input will
alpar@9 1021 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
alpar@9 1022
alpar@9 1023 The in_desc and out_desc parameters of inflateBack() is passed as the
alpar@9 1024 first parameter of in() and out() respectively when they are called. These
alpar@9 1025 descriptors can be optionally used to pass any information that the caller-
alpar@9 1026 supplied in() and out() functions need to do their job.
alpar@9 1027
alpar@9 1028 On return, inflateBack() will set strm->next_in and strm->avail_in to
alpar@9 1029 pass back any unused input that was provided by the last in() call. The
alpar@9 1030 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
alpar@9 1031 if in() or out() returned an error, Z_DATA_ERROR if there was a format error
alpar@9 1032 in the deflate stream (in which case strm->msg is set to indicate the nature
alpar@9 1033 of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
alpar@9 1034 In the case of Z_BUF_ERROR, an input or output error can be distinguished
alpar@9 1035 using strm->next_in which will be Z_NULL only if in() returned an error. If
alpar@9 1036 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
alpar@9 1037 non-zero. (in() will always be called before out(), so strm->next_in is
alpar@9 1038 assured to be defined if out() returns non-zero.) Note that inflateBack()
alpar@9 1039 cannot return Z_OK.
alpar@9 1040 */
alpar@9 1041
alpar@9 1042 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
alpar@9 1043 /*
alpar@9 1044 All memory allocated by inflateBackInit() is freed.
alpar@9 1045
alpar@9 1046 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
alpar@9 1047 state was inconsistent.
alpar@9 1048 */
alpar@9 1049
alpar@9 1050 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
alpar@9 1051 /* Return flags indicating compile-time options.
alpar@9 1052
alpar@9 1053 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
alpar@9 1054 1.0: size of uInt
alpar@9 1055 3.2: size of uLong
alpar@9 1056 5.4: size of voidpf (pointer)
alpar@9 1057 7.6: size of z_off_t
alpar@9 1058
alpar@9 1059 Compiler, assembler, and debug options:
alpar@9 1060 8: DEBUG
alpar@9 1061 9: ASMV or ASMINF -- use ASM code
alpar@9 1062 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
alpar@9 1063 11: 0 (reserved)
alpar@9 1064
alpar@9 1065 One-time table building (smaller code, but not thread-safe if true):
alpar@9 1066 12: BUILDFIXED -- build static block decoding tables when needed
alpar@9 1067 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
alpar@9 1068 14,15: 0 (reserved)
alpar@9 1069
alpar@9 1070 Library content (indicates missing functionality):
alpar@9 1071 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
alpar@9 1072 deflate code when not needed)
alpar@9 1073 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
alpar@9 1074 and decode gzip streams (to avoid linking crc code)
alpar@9 1075 18-19: 0 (reserved)
alpar@9 1076
alpar@9 1077 Operation variations (changes in library functionality):
alpar@9 1078 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
alpar@9 1079 21: FASTEST -- deflate algorithm with only one, lowest compression level
alpar@9 1080 22,23: 0 (reserved)
alpar@9 1081
alpar@9 1082 The sprintf variant used by gzprintf (zero is best):
alpar@9 1083 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
alpar@9 1084 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
alpar@9 1085 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
alpar@9 1086
alpar@9 1087 Remainder:
alpar@9 1088 27-31: 0 (reserved)
alpar@9 1089 */
alpar@9 1090
alpar@9 1091
alpar@9 1092 /* utility functions */
alpar@9 1093
alpar@9 1094 /*
alpar@9 1095 The following utility functions are implemented on top of the basic
alpar@9 1096 stream-oriented functions. To simplify the interface, some default options
alpar@9 1097 are assumed (compression level and memory usage, standard memory allocation
alpar@9 1098 functions). The source code of these utility functions can be modified if
alpar@9 1099 you need special options.
alpar@9 1100 */
alpar@9 1101
alpar@9 1102 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
alpar@9 1103 const Bytef *source, uLong sourceLen));
alpar@9 1104 /*
alpar@9 1105 Compresses the source buffer into the destination buffer. sourceLen is
alpar@9 1106 the byte length of the source buffer. Upon entry, destLen is the total size
alpar@9 1107 of the destination buffer, which must be at least the value returned by
alpar@9 1108 compressBound(sourceLen). Upon exit, destLen is the actual size of the
alpar@9 1109 compressed buffer.
alpar@9 1110
alpar@9 1111 compress returns Z_OK if success, Z_MEM_ERROR if there was not
alpar@9 1112 enough memory, Z_BUF_ERROR if there was not enough room in the output
alpar@9 1113 buffer.
alpar@9 1114 */
alpar@9 1115
alpar@9 1116 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
alpar@9 1117 const Bytef *source, uLong sourceLen,
alpar@9 1118 int level));
alpar@9 1119 /*
alpar@9 1120 Compresses the source buffer into the destination buffer. The level
alpar@9 1121 parameter has the same meaning as in deflateInit. sourceLen is the byte
alpar@9 1122 length of the source buffer. Upon entry, destLen is the total size of the
alpar@9 1123 destination buffer, which must be at least the value returned by
alpar@9 1124 compressBound(sourceLen). Upon exit, destLen is the actual size of the
alpar@9 1125 compressed buffer.
alpar@9 1126
alpar@9 1127 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
alpar@9 1128 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
alpar@9 1129 Z_STREAM_ERROR if the level parameter is invalid.
alpar@9 1130 */
alpar@9 1131
alpar@9 1132 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
alpar@9 1133 /*
alpar@9 1134 compressBound() returns an upper bound on the compressed size after
alpar@9 1135 compress() or compress2() on sourceLen bytes. It would be used before a
alpar@9 1136 compress() or compress2() call to allocate the destination buffer.
alpar@9 1137 */
alpar@9 1138
alpar@9 1139 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
alpar@9 1140 const Bytef *source, uLong sourceLen));
alpar@9 1141 /*
alpar@9 1142 Decompresses the source buffer into the destination buffer. sourceLen is
alpar@9 1143 the byte length of the source buffer. Upon entry, destLen is the total size
alpar@9 1144 of the destination buffer, which must be large enough to hold the entire
alpar@9 1145 uncompressed data. (The size of the uncompressed data must have been saved
alpar@9 1146 previously by the compressor and transmitted to the decompressor by some
alpar@9 1147 mechanism outside the scope of this compression library.) Upon exit, destLen
alpar@9 1148 is the actual size of the uncompressed buffer.
alpar@9 1149
alpar@9 1150 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
alpar@9 1151 enough memory, Z_BUF_ERROR if there was not enough room in the output
alpar@9 1152 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
alpar@9 1153 */
alpar@9 1154
alpar@9 1155
alpar@9 1156 /* gzip file access functions */
alpar@9 1157
alpar@9 1158 /*
alpar@9 1159 This library supports reading and writing files in gzip (.gz) format with
alpar@9 1160 an interface similar to that of stdio, using the functions that start with
alpar@9 1161 "gz". The gzip format is different from the zlib format. gzip is a gzip
alpar@9 1162 wrapper, documented in RFC 1952, wrapped around a deflate stream.
alpar@9 1163 */
alpar@9 1164
alpar@9 1165 typedef voidp gzFile; /* opaque gzip file descriptor */
alpar@9 1166
alpar@9 1167 /*
alpar@9 1168 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
alpar@9 1169
alpar@9 1170 Opens a gzip (.gz) file for reading or writing. The mode parameter is as
alpar@9 1171 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
alpar@9 1172 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
alpar@9 1173 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
alpar@9 1174 for fixed code compression as in "wb9F". (See the description of
alpar@9 1175 deflateInit2 for more information about the strategy parameter.) Also "a"
alpar@9 1176 can be used instead of "w" to request that the gzip stream that will be
alpar@9 1177 written be appended to the file. "+" will result in an error, since reading
alpar@9 1178 and writing to the same gzip file is not supported.
alpar@9 1179
alpar@9 1180 gzopen can be used to read a file which is not in gzip format; in this
alpar@9 1181 case gzread will directly read from the file without decompression.
alpar@9 1182
alpar@9 1183 gzopen returns NULL if the file could not be opened, if there was
alpar@9 1184 insufficient memory to allocate the gzFile state, or if an invalid mode was
alpar@9 1185 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
alpar@9 1186 errno can be checked to determine if the reason gzopen failed was that the
alpar@9 1187 file could not be opened.
alpar@9 1188 */
alpar@9 1189
alpar@9 1190 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
alpar@9 1191 /*
alpar@9 1192 gzdopen associates a gzFile with the file descriptor fd. File descriptors
alpar@9 1193 are obtained from calls like open, dup, creat, pipe or fileno (if the file
alpar@9 1194 has been previously opened with fopen). The mode parameter is as in gzopen.
alpar@9 1195
alpar@9 1196 The next call of gzclose on the returned gzFile will also close the file
alpar@9 1197 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
alpar@9 1198 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
alpar@9 1199 mode);. The duplicated descriptor should be saved to avoid a leak, since
alpar@9 1200 gzdopen does not close fd if it fails.
alpar@9 1201
alpar@9 1202 gzdopen returns NULL if there was insufficient memory to allocate the
alpar@9 1203 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
alpar@9 1204 provided, or '+' was provided), or if fd is -1. The file descriptor is not
alpar@9 1205 used until the next gz* read, write, seek, or close operation, so gzdopen
alpar@9 1206 will not detect if fd is invalid (unless fd is -1).
alpar@9 1207 */
alpar@9 1208
alpar@9 1209 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
alpar@9 1210 /*
alpar@9 1211 Set the internal buffer size used by this library's functions. The
alpar@9 1212 default buffer size is 8192 bytes. This function must be called after
alpar@9 1213 gzopen() or gzdopen(), and before any other calls that read or write the
alpar@9 1214 file. The buffer memory allocation is always deferred to the first read or
alpar@9 1215 write. Two buffers are allocated, either both of the specified size when
alpar@9 1216 writing, or one of the specified size and the other twice that size when
alpar@9 1217 reading. A larger buffer size of, for example, 64K or 128K bytes will
alpar@9 1218 noticeably increase the speed of decompression (reading).
alpar@9 1219
alpar@9 1220 The new buffer size also affects the maximum length for gzprintf().
alpar@9 1221
alpar@9 1222 gzbuffer() returns 0 on success, or -1 on failure, such as being called
alpar@9 1223 too late.
alpar@9 1224 */
alpar@9 1225
alpar@9 1226 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
alpar@9 1227 /*
alpar@9 1228 Dynamically update the compression level or strategy. See the description
alpar@9 1229 of deflateInit2 for the meaning of these parameters.
alpar@9 1230
alpar@9 1231 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
alpar@9 1232 opened for writing.
alpar@9 1233 */
alpar@9 1234
alpar@9 1235 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
alpar@9 1236 /*
alpar@9 1237 Reads the given number of uncompressed bytes from the compressed file. If
alpar@9 1238 the input file was not in gzip format, gzread copies the given number of
alpar@9 1239 bytes into the buffer.
alpar@9 1240
alpar@9 1241 After reaching the end of a gzip stream in the input, gzread will continue
alpar@9 1242 to read, looking for another gzip stream, or failing that, reading the rest
alpar@9 1243 of the input file directly without decompression. The entire input file
alpar@9 1244 will be read if gzread is called until it returns less than the requested
alpar@9 1245 len.
alpar@9 1246
alpar@9 1247 gzread returns the number of uncompressed bytes actually read, less than
alpar@9 1248 len for end of file, or -1 for error.
alpar@9 1249 */
alpar@9 1250
alpar@9 1251 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
alpar@9 1252 voidpc buf, unsigned len));
alpar@9 1253 /*
alpar@9 1254 Writes the given number of uncompressed bytes into the compressed file.
alpar@9 1255 gzwrite returns the number of uncompressed bytes written or 0 in case of
alpar@9 1256 error.
alpar@9 1257 */
alpar@9 1258
alpar@9 1259 ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
alpar@9 1260 /*
alpar@9 1261 Converts, formats, and writes the arguments to the compressed file under
alpar@9 1262 control of the format string, as in fprintf. gzprintf returns the number of
alpar@9 1263 uncompressed bytes actually written, or 0 in case of error. The number of
alpar@9 1264 uncompressed bytes written is limited to 8191, or one less than the buffer
alpar@9 1265 size given to gzbuffer(). The caller should assure that this limit is not
alpar@9 1266 exceeded. If it is exceeded, then gzprintf() will return an error (0) with
alpar@9 1267 nothing written. In this case, there may also be a buffer overflow with
alpar@9 1268 unpredictable consequences, which is possible only if zlib was compiled with
alpar@9 1269 the insecure functions sprintf() or vsprintf() because the secure snprintf()
alpar@9 1270 or vsnprintf() functions were not available. This can be determined using
alpar@9 1271 zlibCompileFlags().
alpar@9 1272 */
alpar@9 1273
alpar@9 1274 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
alpar@9 1275 /*
alpar@9 1276 Writes the given null-terminated string to the compressed file, excluding
alpar@9 1277 the terminating null character.
alpar@9 1278
alpar@9 1279 gzputs returns the number of characters written, or -1 in case of error.
alpar@9 1280 */
alpar@9 1281
alpar@9 1282 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
alpar@9 1283 /*
alpar@9 1284 Reads bytes from the compressed file until len-1 characters are read, or a
alpar@9 1285 newline character is read and transferred to buf, or an end-of-file
alpar@9 1286 condition is encountered. If any characters are read or if len == 1, the
alpar@9 1287 string is terminated with a null character. If no characters are read due
alpar@9 1288 to an end-of-file or len < 1, then the buffer is left untouched.
alpar@9 1289
alpar@9 1290 gzgets returns buf which is a null-terminated string, or it returns NULL
alpar@9 1291 for end-of-file or in case of error. If there was an error, the contents at
alpar@9 1292 buf are indeterminate.
alpar@9 1293 */
alpar@9 1294
alpar@9 1295 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
alpar@9 1296 /*
alpar@9 1297 Writes c, converted to an unsigned char, into the compressed file. gzputc
alpar@9 1298 returns the value that was written, or -1 in case of error.
alpar@9 1299 */
alpar@9 1300
alpar@9 1301 ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
alpar@9 1302 /*
alpar@9 1303 Reads one byte from the compressed file. gzgetc returns this byte or -1
alpar@9 1304 in case of end of file or error.
alpar@9 1305 */
alpar@9 1306
alpar@9 1307 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
alpar@9 1308 /*
alpar@9 1309 Push one character back onto the stream to be read as the first character
alpar@9 1310 on the next read. At least one character of push-back is allowed.
alpar@9 1311 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
alpar@9 1312 fail if c is -1, and may fail if a character has been pushed but not read
alpar@9 1313 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
alpar@9 1314 output buffer size of pushed characters is allowed. (See gzbuffer above.)
alpar@9 1315 The pushed character will be discarded if the stream is repositioned with
alpar@9 1316 gzseek() or gzrewind().
alpar@9 1317 */
alpar@9 1318
alpar@9 1319 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
alpar@9 1320 /*
alpar@9 1321 Flushes all pending output into the compressed file. The parameter flush
alpar@9 1322 is as in the deflate() function. The return value is the zlib error number
alpar@9 1323 (see function gzerror below). gzflush is only permitted when writing.
alpar@9 1324
alpar@9 1325 If the flush parameter is Z_FINISH, the remaining data is written and the
alpar@9 1326 gzip stream is completed in the output. If gzwrite() is called again, a new
alpar@9 1327 gzip stream will be started in the output. gzread() is able to read such
alpar@9 1328 concatented gzip streams.
alpar@9 1329
alpar@9 1330 gzflush should be called only when strictly necessary because it will
alpar@9 1331 degrade compression if called too often.
alpar@9 1332 */
alpar@9 1333
alpar@9 1334 /*
alpar@9 1335 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
alpar@9 1336 z_off_t offset, int whence));
alpar@9 1337
alpar@9 1338 Sets the starting position for the next gzread or gzwrite on the given
alpar@9 1339 compressed file. The offset represents a number of bytes in the
alpar@9 1340 uncompressed data stream. The whence parameter is defined as in lseek(2);
alpar@9 1341 the value SEEK_END is not supported.
alpar@9 1342
alpar@9 1343 If the file is opened for reading, this function is emulated but can be
alpar@9 1344 extremely slow. If the file is opened for writing, only forward seeks are
alpar@9 1345 supported; gzseek then compresses a sequence of zeroes up to the new
alpar@9 1346 starting position.
alpar@9 1347
alpar@9 1348 gzseek returns the resulting offset location as measured in bytes from
alpar@9 1349 the beginning of the uncompressed stream, or -1 in case of error, in
alpar@9 1350 particular if the file is opened for writing and the new starting position
alpar@9 1351 would be before the current position.
alpar@9 1352 */
alpar@9 1353
alpar@9 1354 ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
alpar@9 1355 /*
alpar@9 1356 Rewinds the given file. This function is supported only for reading.
alpar@9 1357
alpar@9 1358 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
alpar@9 1359 */
alpar@9 1360
alpar@9 1361 /*
alpar@9 1362 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
alpar@9 1363
alpar@9 1364 Returns the starting position for the next gzread or gzwrite on the given
alpar@9 1365 compressed file. This position represents a number of bytes in the
alpar@9 1366 uncompressed data stream, and is zero when starting, even if appending or
alpar@9 1367 reading a gzip stream from the middle of a file using gzdopen().
alpar@9 1368
alpar@9 1369 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
alpar@9 1370 */
alpar@9 1371
alpar@9 1372 /*
alpar@9 1373 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
alpar@9 1374
alpar@9 1375 Returns the current offset in the file being read or written. This offset
alpar@9 1376 includes the count of bytes that precede the gzip stream, for example when
alpar@9 1377 appending or when using gzdopen() for reading. When reading, the offset
alpar@9 1378 does not include as yet unused buffered input. This information can be used
alpar@9 1379 for a progress indicator. On error, gzoffset() returns -1.
alpar@9 1380 */
alpar@9 1381
alpar@9 1382 ZEXTERN int ZEXPORT gzeof OF((gzFile file));
alpar@9 1383 /*
alpar@9 1384 Returns true (1) if the end-of-file indicator has been set while reading,
alpar@9 1385 false (0) otherwise. Note that the end-of-file indicator is set only if the
alpar@9 1386 read tried to go past the end of the input, but came up short. Therefore,
alpar@9 1387 just like feof(), gzeof() may return false even if there is no more data to
alpar@9 1388 read, in the event that the last read request was for the exact number of
alpar@9 1389 bytes remaining in the input file. This will happen if the input file size
alpar@9 1390 is an exact multiple of the buffer size.
alpar@9 1391
alpar@9 1392 If gzeof() returns true, then the read functions will return no more data,
alpar@9 1393 unless the end-of-file indicator is reset by gzclearerr() and the input file
alpar@9 1394 has grown since the previous end of file was detected.
alpar@9 1395 */
alpar@9 1396
alpar@9 1397 ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
alpar@9 1398 /*
alpar@9 1399 Returns true (1) if file is being copied directly while reading, or false
alpar@9 1400 (0) if file is a gzip stream being decompressed. This state can change from
alpar@9 1401 false to true while reading the input file if the end of a gzip stream is
alpar@9 1402 reached, but is followed by data that is not another gzip stream.
alpar@9 1403
alpar@9 1404 If the input file is empty, gzdirect() will return true, since the input
alpar@9 1405 does not contain a gzip stream.
alpar@9 1406
alpar@9 1407 If gzdirect() is used immediately after gzopen() or gzdopen() it will
alpar@9 1408 cause buffers to be allocated to allow reading the file to determine if it
alpar@9 1409 is a gzip file. Therefore if gzbuffer() is used, it should be called before
alpar@9 1410 gzdirect().
alpar@9 1411 */
alpar@9 1412
alpar@9 1413 ZEXTERN int ZEXPORT gzclose OF((gzFile file));
alpar@9 1414 /*
alpar@9 1415 Flushes all pending output if necessary, closes the compressed file and
alpar@9 1416 deallocates the (de)compression state. Note that once file is closed, you
alpar@9 1417 cannot call gzerror with file, since its structures have been deallocated.
alpar@9 1418 gzclose must not be called more than once on the same file, just as free
alpar@9 1419 must not be called more than once on the same allocation.
alpar@9 1420
alpar@9 1421 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
alpar@9 1422 file operation error, or Z_OK on success.
alpar@9 1423 */
alpar@9 1424
alpar@9 1425 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
alpar@9 1426 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
alpar@9 1427 /*
alpar@9 1428 Same as gzclose(), but gzclose_r() is only for use when reading, and
alpar@9 1429 gzclose_w() is only for use when writing or appending. The advantage to
alpar@9 1430 using these instead of gzclose() is that they avoid linking in zlib
alpar@9 1431 compression or decompression code that is not used when only reading or only
alpar@9 1432 writing respectively. If gzclose() is used, then both compression and
alpar@9 1433 decompression code will be included the application when linking to a static
alpar@9 1434 zlib library.
alpar@9 1435 */
alpar@9 1436
alpar@9 1437 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
alpar@9 1438 /*
alpar@9 1439 Returns the error message for the last error which occurred on the given
alpar@9 1440 compressed file. errnum is set to zlib error number. If an error occurred
alpar@9 1441 in the file system and not in the compression library, errnum is set to
alpar@9 1442 Z_ERRNO and the application may consult errno to get the exact error code.
alpar@9 1443
alpar@9 1444 The application must not modify the returned string. Future calls to
alpar@9 1445 this function may invalidate the previously returned string. If file is
alpar@9 1446 closed, then the string previously returned by gzerror will no longer be
alpar@9 1447 available.
alpar@9 1448
alpar@9 1449 gzerror() should be used to distinguish errors from end-of-file for those
alpar@9 1450 functions above that do not distinguish those cases in their return values.
alpar@9 1451 */
alpar@9 1452
alpar@9 1453 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
alpar@9 1454 /*
alpar@9 1455 Clears the error and end-of-file flags for file. This is analogous to the
alpar@9 1456 clearerr() function in stdio. This is useful for continuing to read a gzip
alpar@9 1457 file that is being written concurrently.
alpar@9 1458 */
alpar@9 1459
alpar@9 1460
alpar@9 1461 /* checksum functions */
alpar@9 1462
alpar@9 1463 /*
alpar@9 1464 These functions are not related to compression but are exported
alpar@9 1465 anyway because they might be useful in applications using the compression
alpar@9 1466 library.
alpar@9 1467 */
alpar@9 1468
alpar@9 1469 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
alpar@9 1470 /*
alpar@9 1471 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
alpar@9 1472 return the updated checksum. If buf is Z_NULL, this function returns the
alpar@9 1473 required initial value for the checksum.
alpar@9 1474
alpar@9 1475 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
alpar@9 1476 much faster.
alpar@9 1477
alpar@9 1478 Usage example:
alpar@9 1479
alpar@9 1480 uLong adler = adler32(0L, Z_NULL, 0);
alpar@9 1481
alpar@9 1482 while (read_buffer(buffer, length) != EOF) {
alpar@9 1483 adler = adler32(adler, buffer, length);
alpar@9 1484 }
alpar@9 1485 if (adler != original_adler) error();
alpar@9 1486 */
alpar@9 1487
alpar@9 1488 /*
alpar@9 1489 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
alpar@9 1490 z_off_t len2));
alpar@9 1491
alpar@9 1492 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
alpar@9 1493 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
alpar@9 1494 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
alpar@9 1495 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
alpar@9 1496 */
alpar@9 1497
alpar@9 1498 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
alpar@9 1499 /*
alpar@9 1500 Update a running CRC-32 with the bytes buf[0..len-1] and return the
alpar@9 1501 updated CRC-32. If buf is Z_NULL, this function returns the required
alpar@9 1502 initial value for the for the crc. Pre- and post-conditioning (one's
alpar@9 1503 complement) is performed within this function so it shouldn't be done by the
alpar@9 1504 application.
alpar@9 1505
alpar@9 1506 Usage example:
alpar@9 1507
alpar@9 1508 uLong crc = crc32(0L, Z_NULL, 0);
alpar@9 1509
alpar@9 1510 while (read_buffer(buffer, length) != EOF) {
alpar@9 1511 crc = crc32(crc, buffer, length);
alpar@9 1512 }
alpar@9 1513 if (crc != original_crc) error();
alpar@9 1514 */
alpar@9 1515
alpar@9 1516 /*
alpar@9 1517 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
alpar@9 1518
alpar@9 1519 Combine two CRC-32 check values into one. For two sequences of bytes,
alpar@9 1520 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
alpar@9 1521 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
alpar@9 1522 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
alpar@9 1523 len2.
alpar@9 1524 */
alpar@9 1525
alpar@9 1526
alpar@9 1527 /* various hacks, don't look :) */
alpar@9 1528
alpar@9 1529 /* deflateInit and inflateInit are macros to allow checking the zlib version
alpar@9 1530 * and the compiler's view of z_stream:
alpar@9 1531 */
alpar@9 1532 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
alpar@9 1533 const char *version, int stream_size));
alpar@9 1534 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
alpar@9 1535 const char *version, int stream_size));
alpar@9 1536 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
alpar@9 1537 int windowBits, int memLevel,
alpar@9 1538 int strategy, const char *version,
alpar@9 1539 int stream_size));
alpar@9 1540 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
alpar@9 1541 const char *version, int stream_size));
alpar@9 1542 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
alpar@9 1543 unsigned char FAR *window,
alpar@9 1544 const char *version,
alpar@9 1545 int stream_size));
alpar@9 1546 #define deflateInit(strm, level) \
alpar@9 1547 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
alpar@9 1548 #define inflateInit(strm) \
alpar@9 1549 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
alpar@9 1550 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
alpar@9 1551 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
alpar@9 1552 (strategy), ZLIB_VERSION, sizeof(z_stream))
alpar@9 1553 #define inflateInit2(strm, windowBits) \
alpar@9 1554 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
alpar@9 1555 #define inflateBackInit(strm, windowBits, window) \
alpar@9 1556 inflateBackInit_((strm), (windowBits), (window), \
alpar@9 1557 ZLIB_VERSION, sizeof(z_stream))
alpar@9 1558
alpar@9 1559 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
alpar@9 1560 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
alpar@9 1561 * both are true, the application gets the *64 functions, and the regular
alpar@9 1562 * functions are changed to 64 bits) -- in case these are set on systems
alpar@9 1563 * without large file support, _LFS64_LARGEFILE must also be true
alpar@9 1564 */
alpar@9 1565 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
alpar@9 1566 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
alpar@9 1567 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
alpar@9 1568 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
alpar@9 1569 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
alpar@9 1570 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
alpar@9 1571 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
alpar@9 1572 #endif
alpar@9 1573
alpar@9 1574 #if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0
alpar@9 1575 # define gzopen gzopen64
alpar@9 1576 # define gzseek gzseek64
alpar@9 1577 # define gztell gztell64
alpar@9 1578 # define gzoffset gzoffset64
alpar@9 1579 # define adler32_combine adler32_combine64
alpar@9 1580 # define crc32_combine crc32_combine64
alpar@9 1581 # ifdef _LARGEFILE64_SOURCE
alpar@9 1582 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
alpar@9 1583 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
alpar@9 1584 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
alpar@9 1585 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
alpar@9 1586 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
alpar@9 1587 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
alpar@9 1588 # endif
alpar@9 1589 #else
alpar@9 1590 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
alpar@9 1591 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
alpar@9 1592 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
alpar@9 1593 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
alpar@9 1594 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
alpar@9 1595 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
alpar@9 1596 #endif
alpar@9 1597
alpar@9 1598 /* hack for buggy compilers */
alpar@9 1599 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
alpar@9 1600 struct internal_state {int dummy;};
alpar@9 1601 #endif
alpar@9 1602
alpar@9 1603 /* undocumented functions */
alpar@9 1604 ZEXTERN const char * ZEXPORT zError OF((int));
alpar@9 1605 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
alpar@9 1606 ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
alpar@9 1607 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
alpar@9 1608
alpar@9 1609 #ifdef __cplusplus
alpar@9 1610 }
alpar@9 1611 #endif
alpar@9 1612
alpar@9 1613 #endif /* ZLIB_H */