modules/zlib/src/zlib.h

Wed, 31 Dec 2014 06:09:35 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Wed, 31 Dec 2014 06:09:35 +0100
changeset 0
6474c204b198
permissions
-rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

michael@0 1 /* zlib.h -- interface of the 'zlib' general purpose compression library
michael@0 2 version 1.2.8, April 28th, 2013
michael@0 3
michael@0 4 Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
michael@0 5
michael@0 6 This software is provided 'as-is', without any express or implied
michael@0 7 warranty. In no event will the authors be held liable for any damages
michael@0 8 arising from the use of this software.
michael@0 9
michael@0 10 Permission is granted to anyone to use this software for any purpose,
michael@0 11 including commercial applications, and to alter it and redistribute it
michael@0 12 freely, subject to the following restrictions:
michael@0 13
michael@0 14 1. The origin of this software must not be misrepresented; you must not
michael@0 15 claim that you wrote the original software. If you use this software
michael@0 16 in a product, an acknowledgment in the product documentation would be
michael@0 17 appreciated but is not required.
michael@0 18 2. Altered source versions must be plainly marked as such, and must not be
michael@0 19 misrepresented as being the original software.
michael@0 20 3. This notice may not be removed or altered from any source distribution.
michael@0 21
michael@0 22 Jean-loup Gailly Mark Adler
michael@0 23 jloup@gzip.org madler@alumni.caltech.edu
michael@0 24
michael@0 25
michael@0 26 The data format used by the zlib library is described by RFCs (Request for
michael@0 27 Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
michael@0 28 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
michael@0 29 */
michael@0 30
michael@0 31 #ifndef ZLIB_H
michael@0 32 #define ZLIB_H
michael@0 33
michael@0 34 #include "zconf.h"
michael@0 35
michael@0 36 #ifdef __cplusplus
michael@0 37 extern "C" {
michael@0 38 #endif
michael@0 39
michael@0 40 #define ZLIB_VERSION "1.2.8"
michael@0 41 #define ZLIB_VERNUM 0x1280
michael@0 42 #define ZLIB_VER_MAJOR 1
michael@0 43 #define ZLIB_VER_MINOR 2
michael@0 44 #define ZLIB_VER_REVISION 8
michael@0 45 #define ZLIB_VER_SUBREVISION 0
michael@0 46
michael@0 47 /*
michael@0 48 The 'zlib' compression library provides in-memory compression and
michael@0 49 decompression functions, including integrity checks of the uncompressed data.
michael@0 50 This version of the library supports only one compression method (deflation)
michael@0 51 but other algorithms will be added later and will have the same stream
michael@0 52 interface.
michael@0 53
michael@0 54 Compression can be done in a single step if the buffers are large enough,
michael@0 55 or can be done by repeated calls of the compression function. In the latter
michael@0 56 case, the application must provide more input and/or consume the output
michael@0 57 (providing more output space) before each call.
michael@0 58
michael@0 59 The compressed data format used by default by the in-memory functions is
michael@0 60 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
michael@0 61 around a deflate stream, which is itself documented in RFC 1951.
michael@0 62
michael@0 63 The library also supports reading and writing files in gzip (.gz) format
michael@0 64 with an interface similar to that of stdio using the functions that start
michael@0 65 with "gz". The gzip format is different from the zlib format. gzip is a
michael@0 66 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
michael@0 67
michael@0 68 This library can optionally read and write gzip streams in memory as well.
michael@0 69
michael@0 70 The zlib format was designed to be compact and fast for use in memory
michael@0 71 and on communications channels. The gzip format was designed for single-
michael@0 72 file compression on file systems, has a larger header than zlib to maintain
michael@0 73 directory information, and uses a different, slower check method than zlib.
michael@0 74
michael@0 75 The library does not install any signal handler. The decoder checks
michael@0 76 the consistency of the compressed data, so the library should never crash
michael@0 77 even in case of corrupted input.
michael@0 78 */
michael@0 79
michael@0 80 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
michael@0 81 typedef void (*free_func) OF((voidpf opaque, voidpf address));
michael@0 82
michael@0 83 struct internal_state;
michael@0 84
michael@0 85 typedef struct z_stream_s {
michael@0 86 z_const Bytef *next_in; /* next input byte */
michael@0 87 uInt avail_in; /* number of bytes available at next_in */
michael@0 88 uLong total_in; /* total number of input bytes read so far */
michael@0 89
michael@0 90 Bytef *next_out; /* next output byte should be put there */
michael@0 91 uInt avail_out; /* remaining free space at next_out */
michael@0 92 uLong total_out; /* total number of bytes output so far */
michael@0 93
michael@0 94 z_const char *msg; /* last error message, NULL if no error */
michael@0 95 struct internal_state FAR *state; /* not visible by applications */
michael@0 96
michael@0 97 alloc_func zalloc; /* used to allocate the internal state */
michael@0 98 free_func zfree; /* used to free the internal state */
michael@0 99 voidpf opaque; /* private data object passed to zalloc and zfree */
michael@0 100
michael@0 101 int data_type; /* best guess about the data type: binary or text */
michael@0 102 uLong adler; /* adler32 value of the uncompressed data */
michael@0 103 uLong reserved; /* reserved for future use */
michael@0 104 } z_stream;
michael@0 105
michael@0 106 typedef z_stream FAR *z_streamp;
michael@0 107
michael@0 108 /*
michael@0 109 gzip header information passed to and from zlib routines. See RFC 1952
michael@0 110 for more details on the meanings of these fields.
michael@0 111 */
michael@0 112 typedef struct gz_header_s {
michael@0 113 int text; /* true if compressed data believed to be text */
michael@0 114 uLong time; /* modification time */
michael@0 115 int xflags; /* extra flags (not used when writing a gzip file) */
michael@0 116 int os; /* operating system */
michael@0 117 Bytef *extra; /* pointer to extra field or Z_NULL if none */
michael@0 118 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
michael@0 119 uInt extra_max; /* space at extra (only when reading header) */
michael@0 120 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
michael@0 121 uInt name_max; /* space at name (only when reading header) */
michael@0 122 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
michael@0 123 uInt comm_max; /* space at comment (only when reading header) */
michael@0 124 int hcrc; /* true if there was or will be a header crc */
michael@0 125 int done; /* true when done reading gzip header (not used
michael@0 126 when writing a gzip file) */
michael@0 127 } gz_header;
michael@0 128
michael@0 129 typedef gz_header FAR *gz_headerp;
michael@0 130
michael@0 131 /*
michael@0 132 The application must update next_in and avail_in when avail_in has dropped
michael@0 133 to zero. It must update next_out and avail_out when avail_out has dropped
michael@0 134 to zero. The application must initialize zalloc, zfree and opaque before
michael@0 135 calling the init function. All other fields are set by the compression
michael@0 136 library and must not be updated by the application.
michael@0 137
michael@0 138 The opaque value provided by the application will be passed as the first
michael@0 139 parameter for calls of zalloc and zfree. This can be useful for custom
michael@0 140 memory management. The compression library attaches no meaning to the
michael@0 141 opaque value.
michael@0 142
michael@0 143 zalloc must return Z_NULL if there is not enough memory for the object.
michael@0 144 If zlib is used in a multi-threaded application, zalloc and zfree must be
michael@0 145 thread safe.
michael@0 146
michael@0 147 On 16-bit systems, the functions zalloc and zfree must be able to allocate
michael@0 148 exactly 65536 bytes, but will not be required to allocate more than this if
michael@0 149 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
michael@0 150 returned by zalloc for objects of exactly 65536 bytes *must* have their
michael@0 151 offset normalized to zero. The default allocation function provided by this
michael@0 152 library ensures this (see zutil.c). To reduce memory requirements and avoid
michael@0 153 any allocation of 64K objects, at the expense of compression ratio, compile
michael@0 154 the library with -DMAX_WBITS=14 (see zconf.h).
michael@0 155
michael@0 156 The fields total_in and total_out can be used for statistics or progress
michael@0 157 reports. After compression, total_in holds the total size of the
michael@0 158 uncompressed data and may be saved for use in the decompressor (particularly
michael@0 159 if the decompressor wants to decompress everything in a single step).
michael@0 160 */
michael@0 161
michael@0 162 /* constants */
michael@0 163
michael@0 164 #define Z_NO_FLUSH 0
michael@0 165 #define Z_PARTIAL_FLUSH 1
michael@0 166 #define Z_SYNC_FLUSH 2
michael@0 167 #define Z_FULL_FLUSH 3
michael@0 168 #define Z_FINISH 4
michael@0 169 #define Z_BLOCK 5
michael@0 170 #define Z_TREES 6
michael@0 171 /* Allowed flush values; see deflate() and inflate() below for details */
michael@0 172
michael@0 173 #define Z_OK 0
michael@0 174 #define Z_STREAM_END 1
michael@0 175 #define Z_NEED_DICT 2
michael@0 176 #define Z_ERRNO (-1)
michael@0 177 #define Z_STREAM_ERROR (-2)
michael@0 178 #define Z_DATA_ERROR (-3)
michael@0 179 #define Z_MEM_ERROR (-4)
michael@0 180 #define Z_BUF_ERROR (-5)
michael@0 181 #define Z_VERSION_ERROR (-6)
michael@0 182 /* Return codes for the compression/decompression functions. Negative values
michael@0 183 * are errors, positive values are used for special but normal events.
michael@0 184 */
michael@0 185
michael@0 186 #define Z_NO_COMPRESSION 0
michael@0 187 #define Z_BEST_SPEED 1
michael@0 188 #define Z_BEST_COMPRESSION 9
michael@0 189 #define Z_DEFAULT_COMPRESSION (-1)
michael@0 190 /* compression levels */
michael@0 191
michael@0 192 #define Z_FILTERED 1
michael@0 193 #define Z_HUFFMAN_ONLY 2
michael@0 194 #define Z_RLE 3
michael@0 195 #define Z_FIXED 4
michael@0 196 #define Z_DEFAULT_STRATEGY 0
michael@0 197 /* compression strategy; see deflateInit2() below for details */
michael@0 198
michael@0 199 #define Z_BINARY 0
michael@0 200 #define Z_TEXT 1
michael@0 201 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
michael@0 202 #define Z_UNKNOWN 2
michael@0 203 /* Possible values of the data_type field (though see inflate()) */
michael@0 204
michael@0 205 #define Z_DEFLATED 8
michael@0 206 /* The deflate compression method (the only one supported in this version) */
michael@0 207
michael@0 208 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
michael@0 209
michael@0 210 #define zlib_version zlibVersion()
michael@0 211 /* for compatibility with versions < 1.0.2 */
michael@0 212
michael@0 213
michael@0 214 /* basic functions */
michael@0 215
michael@0 216 ZEXTERN const char * ZEXPORT zlibVersion OF((void));
michael@0 217 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
michael@0 218 If the first character differs, the library code actually used is not
michael@0 219 compatible with the zlib.h header file used by the application. This check
michael@0 220 is automatically made by deflateInit and inflateInit.
michael@0 221 */
michael@0 222
michael@0 223 /*
michael@0 224 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
michael@0 225
michael@0 226 Initializes the internal stream state for compression. The fields
michael@0 227 zalloc, zfree and opaque must be initialized before by the caller. If
michael@0 228 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
michael@0 229 allocation functions.
michael@0 230
michael@0 231 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
michael@0 232 1 gives best speed, 9 gives best compression, 0 gives no compression at all
michael@0 233 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
michael@0 234 requests a default compromise between speed and compression (currently
michael@0 235 equivalent to level 6).
michael@0 236
michael@0 237 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
michael@0 238 memory, Z_STREAM_ERROR if level is not a valid compression level, or
michael@0 239 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
michael@0 240 with the version assumed by the caller (ZLIB_VERSION). msg is set to null
michael@0 241 if there is no error message. deflateInit does not perform any compression:
michael@0 242 this will be done by deflate().
michael@0 243 */
michael@0 244
michael@0 245
michael@0 246 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
michael@0 247 /*
michael@0 248 deflate compresses as much data as possible, and stops when the input
michael@0 249 buffer becomes empty or the output buffer becomes full. It may introduce
michael@0 250 some output latency (reading input without producing any output) except when
michael@0 251 forced to flush.
michael@0 252
michael@0 253 The detailed semantics are as follows. deflate performs one or both of the
michael@0 254 following actions:
michael@0 255
michael@0 256 - Compress more input starting at next_in and update next_in and avail_in
michael@0 257 accordingly. If not all input can be processed (because there is not
michael@0 258 enough room in the output buffer), next_in and avail_in are updated and
michael@0 259 processing will resume at this point for the next call of deflate().
michael@0 260
michael@0 261 - Provide more output starting at next_out and update next_out and avail_out
michael@0 262 accordingly. This action is forced if the parameter flush is non zero.
michael@0 263 Forcing flush frequently degrades the compression ratio, so this parameter
michael@0 264 should be set only when necessary (in interactive applications). Some
michael@0 265 output may be provided even if flush is not set.
michael@0 266
michael@0 267 Before the call of deflate(), the application should ensure that at least
michael@0 268 one of the actions is possible, by providing more input and/or consuming more
michael@0 269 output, and updating avail_in or avail_out accordingly; avail_out should
michael@0 270 never be zero before the call. The application can consume the compressed
michael@0 271 output when it wants, for example when the output buffer is full (avail_out
michael@0 272 == 0), or after each call of deflate(). If deflate returns Z_OK and with
michael@0 273 zero avail_out, it must be called again after making room in the output
michael@0 274 buffer because there might be more output pending.
michael@0 275
michael@0 276 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
michael@0 277 decide how much data to accumulate before producing output, in order to
michael@0 278 maximize compression.
michael@0 279
michael@0 280 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
michael@0 281 flushed to the output buffer and the output is aligned on a byte boundary, so
michael@0 282 that the decompressor can get all input data available so far. (In
michael@0 283 particular avail_in is zero after the call if enough output space has been
michael@0 284 provided before the call.) Flushing may degrade compression for some
michael@0 285 compression algorithms and so it should be used only when necessary. This
michael@0 286 completes the current deflate block and follows it with an empty stored block
michael@0 287 that is three bits plus filler bits to the next byte, followed by four bytes
michael@0 288 (00 00 ff ff).
michael@0 289
michael@0 290 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
michael@0 291 output buffer, but the output is not aligned to a byte boundary. All of the
michael@0 292 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
michael@0 293 This completes the current deflate block and follows it with an empty fixed
michael@0 294 codes block that is 10 bits long. This assures that enough bytes are output
michael@0 295 in order for the decompressor to finish the block before the empty fixed code
michael@0 296 block.
michael@0 297
michael@0 298 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
michael@0 299 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
michael@0 300 seven bits of the current block are held to be written as the next byte after
michael@0 301 the next deflate block is completed. In this case, the decompressor may not
michael@0 302 be provided enough bits at this point in order to complete decompression of
michael@0 303 the data provided so far to the compressor. It may need to wait for the next
michael@0 304 block to be emitted. This is for advanced applications that need to control
michael@0 305 the emission of deflate blocks.
michael@0 306
michael@0 307 If flush is set to Z_FULL_FLUSH, all output is flushed as with
michael@0 308 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
michael@0 309 restart from this point if previous compressed data has been damaged or if
michael@0 310 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
michael@0 311 compression.
michael@0 312
michael@0 313 If deflate returns with avail_out == 0, this function must be called again
michael@0 314 with the same value of the flush parameter and more output space (updated
michael@0 315 avail_out), until the flush is complete (deflate returns with non-zero
michael@0 316 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
michael@0 317 avail_out is greater than six to avoid repeated flush markers due to
michael@0 318 avail_out == 0 on return.
michael@0 319
michael@0 320 If the parameter flush is set to Z_FINISH, pending input is processed,
michael@0 321 pending output is flushed and deflate returns with Z_STREAM_END if there was
michael@0 322 enough output space; if deflate returns with Z_OK, this function must be
michael@0 323 called again with Z_FINISH and more output space (updated avail_out) but no
michael@0 324 more input data, until it returns with Z_STREAM_END or an error. After
michael@0 325 deflate has returned Z_STREAM_END, the only possible operations on the stream
michael@0 326 are deflateReset or deflateEnd.
michael@0 327
michael@0 328 Z_FINISH can be used immediately after deflateInit if all the compression
michael@0 329 is to be done in a single step. In this case, avail_out must be at least the
michael@0 330 value returned by deflateBound (see below). Then deflate is guaranteed to
michael@0 331 return Z_STREAM_END. If not enough output space is provided, deflate will
michael@0 332 not return Z_STREAM_END, and it must be called again as described above.
michael@0 333
michael@0 334 deflate() sets strm->adler to the adler32 checksum of all input read
michael@0 335 so far (that is, total_in bytes).
michael@0 336
michael@0 337 deflate() may update strm->data_type if it can make a good guess about
michael@0 338 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
michael@0 339 binary. This field is only for information purposes and does not affect the
michael@0 340 compression algorithm in any manner.
michael@0 341
michael@0 342 deflate() returns Z_OK if some progress has been made (more input
michael@0 343 processed or more output produced), Z_STREAM_END if all input has been
michael@0 344 consumed and all output has been produced (only when flush is set to
michael@0 345 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
michael@0 346 if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
michael@0 347 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
michael@0 348 fatal, and deflate() can be called again with more input and more output
michael@0 349 space to continue compressing.
michael@0 350 */
michael@0 351
michael@0 352
michael@0 353 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
michael@0 354 /*
michael@0 355 All dynamically allocated data structures for this stream are freed.
michael@0 356 This function discards any unprocessed input and does not flush any pending
michael@0 357 output.
michael@0 358
michael@0 359 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
michael@0 360 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
michael@0 361 prematurely (some input or output was discarded). In the error case, msg
michael@0 362 may be set but then points to a static string (which must not be
michael@0 363 deallocated).
michael@0 364 */
michael@0 365
michael@0 366
michael@0 367 /*
michael@0 368 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
michael@0 369
michael@0 370 Initializes the internal stream state for decompression. The fields
michael@0 371 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
michael@0 372 the caller. If next_in is not Z_NULL and avail_in is large enough (the
michael@0 373 exact value depends on the compression method), inflateInit determines the
michael@0 374 compression method from the zlib header and allocates all data structures
michael@0 375 accordingly; otherwise the allocation will be deferred to the first call of
michael@0 376 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
michael@0 377 use default allocation functions.
michael@0 378
michael@0 379 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
michael@0 380 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
michael@0 381 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
michael@0 382 invalid, such as a null pointer to the structure. msg is set to null if
michael@0 383 there is no error message. inflateInit does not perform any decompression
michael@0 384 apart from possibly reading the zlib header if present: actual decompression
michael@0 385 will be done by inflate(). (So next_in and avail_in may be modified, but
michael@0 386 next_out and avail_out are unused and unchanged.) The current implementation
michael@0 387 of inflateInit() does not process any header information -- that is deferred
michael@0 388 until inflate() is called.
michael@0 389 */
michael@0 390
michael@0 391
michael@0 392 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
michael@0 393 /*
michael@0 394 inflate decompresses as much data as possible, and stops when the input
michael@0 395 buffer becomes empty or the output buffer becomes full. It may introduce
michael@0 396 some output latency (reading input without producing any output) except when
michael@0 397 forced to flush.
michael@0 398
michael@0 399 The detailed semantics are as follows. inflate performs one or both of the
michael@0 400 following actions:
michael@0 401
michael@0 402 - Decompress more input starting at next_in and update next_in and avail_in
michael@0 403 accordingly. If not all input can be processed (because there is not
michael@0 404 enough room in the output buffer), next_in is updated and processing will
michael@0 405 resume at this point for the next call of inflate().
michael@0 406
michael@0 407 - Provide more output starting at next_out and update next_out and avail_out
michael@0 408 accordingly. inflate() provides as much output as possible, until there is
michael@0 409 no more input data or no more space in the output buffer (see below about
michael@0 410 the flush parameter).
michael@0 411
michael@0 412 Before the call of inflate(), the application should ensure that at least
michael@0 413 one of the actions is possible, by providing more input and/or consuming more
michael@0 414 output, and updating the next_* and avail_* values accordingly. The
michael@0 415 application can consume the uncompressed output when it wants, for example
michael@0 416 when the output buffer is full (avail_out == 0), or after each call of
michael@0 417 inflate(). If inflate returns Z_OK and with zero avail_out, it must be
michael@0 418 called again after making room in the output buffer because there might be
michael@0 419 more output pending.
michael@0 420
michael@0 421 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
michael@0 422 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
michael@0 423 output as possible to the output buffer. Z_BLOCK requests that inflate()
michael@0 424 stop if and when it gets to the next deflate block boundary. When decoding
michael@0 425 the zlib or gzip format, this will cause inflate() to return immediately
michael@0 426 after the header and before the first block. When doing a raw inflate,
michael@0 427 inflate() will go ahead and process the first block, and will return when it
michael@0 428 gets to the end of that block, or when it runs out of data.
michael@0 429
michael@0 430 The Z_BLOCK option assists in appending to or combining deflate streams.
michael@0 431 Also to assist in this, on return inflate() will set strm->data_type to the
michael@0 432 number of unused bits in the last byte taken from strm->next_in, plus 64 if
michael@0 433 inflate() is currently decoding the last block in the deflate stream, plus
michael@0 434 128 if inflate() returned immediately after decoding an end-of-block code or
michael@0 435 decoding the complete header up to just before the first byte of the deflate
michael@0 436 stream. The end-of-block will not be indicated until all of the uncompressed
michael@0 437 data from that block has been written to strm->next_out. The number of
michael@0 438 unused bits may in general be greater than seven, except when bit 7 of
michael@0 439 data_type is set, in which case the number of unused bits will be less than
michael@0 440 eight. data_type is set as noted here every time inflate() returns for all
michael@0 441 flush options, and so can be used to determine the amount of currently
michael@0 442 consumed input in bits.
michael@0 443
michael@0 444 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
michael@0 445 end of each deflate block header is reached, before any actual data in that
michael@0 446 block is decoded. This allows the caller to determine the length of the
michael@0 447 deflate block header for later use in random access within a deflate block.
michael@0 448 256 is added to the value of strm->data_type when inflate() returns
michael@0 449 immediately after reaching the end of the deflate block header.
michael@0 450
michael@0 451 inflate() should normally be called until it returns Z_STREAM_END or an
michael@0 452 error. However if all decompression is to be performed in a single step (a
michael@0 453 single call of inflate), the parameter flush should be set to Z_FINISH. In
michael@0 454 this case all pending input is processed and all pending output is flushed;
michael@0 455 avail_out must be large enough to hold all of the uncompressed data for the
michael@0 456 operation to complete. (The size of the uncompressed data may have been
michael@0 457 saved by the compressor for this purpose.) The use of Z_FINISH is not
michael@0 458 required to perform an inflation in one step. However it may be used to
michael@0 459 inform inflate that a faster approach can be used for the single inflate()
michael@0 460 call. Z_FINISH also informs inflate to not maintain a sliding window if the
michael@0 461 stream completes, which reduces inflate's memory footprint. If the stream
michael@0 462 does not complete, either because not all of the stream is provided or not
michael@0 463 enough output space is provided, then a sliding window will be allocated and
michael@0 464 inflate() can be called again to continue the operation as if Z_NO_FLUSH had
michael@0 465 been used.
michael@0 466
michael@0 467 In this implementation, inflate() always flushes as much output as
michael@0 468 possible to the output buffer, and always uses the faster approach on the
michael@0 469 first call. So the effects of the flush parameter in this implementation are
michael@0 470 on the return value of inflate() as noted below, when inflate() returns early
michael@0 471 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
michael@0 472 memory for a sliding window when Z_FINISH is used.
michael@0 473
michael@0 474 If a preset dictionary is needed after this call (see inflateSetDictionary
michael@0 475 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
michael@0 476 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
michael@0 477 strm->adler to the Adler-32 checksum of all output produced so far (that is,
michael@0 478 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
michael@0 479 below. At the end of the stream, inflate() checks that its computed adler32
michael@0 480 checksum is equal to that saved by the compressor and returns Z_STREAM_END
michael@0 481 only if the checksum is correct.
michael@0 482
michael@0 483 inflate() can decompress and check either zlib-wrapped or gzip-wrapped
michael@0 484 deflate data. The header type is detected automatically, if requested when
michael@0 485 initializing with inflateInit2(). Any information contained in the gzip
michael@0 486 header is not retained, so applications that need that information should
michael@0 487 instead use raw inflate, see inflateInit2() below, or inflateBack() and
michael@0 488 perform their own processing of the gzip header and trailer. When processing
michael@0 489 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
michael@0 490 producted so far. The CRC-32 is checked against the gzip trailer.
michael@0 491
michael@0 492 inflate() returns Z_OK if some progress has been made (more input processed
michael@0 493 or more output produced), Z_STREAM_END if the end of the compressed data has
michael@0 494 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
michael@0 495 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
michael@0 496 corrupted (input stream not conforming to the zlib format or incorrect check
michael@0 497 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
michael@0 498 next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
michael@0 499 Z_BUF_ERROR if no progress is possible or if there was not enough room in the
michael@0 500 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
michael@0 501 inflate() can be called again with more input and more output space to
michael@0 502 continue decompressing. If Z_DATA_ERROR is returned, the application may
michael@0 503 then call inflateSync() to look for a good compression block if a partial
michael@0 504 recovery of the data is desired.
michael@0 505 */
michael@0 506
michael@0 507
michael@0 508 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
michael@0 509 /*
michael@0 510 All dynamically allocated data structures for this stream are freed.
michael@0 511 This function discards any unprocessed input and does not flush any pending
michael@0 512 output.
michael@0 513
michael@0 514 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
michael@0 515 was inconsistent. In the error case, msg may be set but then points to a
michael@0 516 static string (which must not be deallocated).
michael@0 517 */
michael@0 518
michael@0 519
michael@0 520 /* Advanced functions */
michael@0 521
michael@0 522 /*
michael@0 523 The following functions are needed only in some special applications.
michael@0 524 */
michael@0 525
michael@0 526 /*
michael@0 527 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
michael@0 528 int level,
michael@0 529 int method,
michael@0 530 int windowBits,
michael@0 531 int memLevel,
michael@0 532 int strategy));
michael@0 533
michael@0 534 This is another version of deflateInit with more compression options. The
michael@0 535 fields next_in, zalloc, zfree and opaque must be initialized before by the
michael@0 536 caller.
michael@0 537
michael@0 538 The method parameter is the compression method. It must be Z_DEFLATED in
michael@0 539 this version of the library.
michael@0 540
michael@0 541 The windowBits parameter is the base two logarithm of the window size
michael@0 542 (the size of the history buffer). It should be in the range 8..15 for this
michael@0 543 version of the library. Larger values of this parameter result in better
michael@0 544 compression at the expense of memory usage. The default value is 15 if
michael@0 545 deflateInit is used instead.
michael@0 546
michael@0 547 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
michael@0 548 determines the window size. deflate() will then generate raw deflate data
michael@0 549 with no zlib header or trailer, and will not compute an adler32 check value.
michael@0 550
michael@0 551 windowBits can also be greater than 15 for optional gzip encoding. Add
michael@0 552 16 to windowBits to write a simple gzip header and trailer around the
michael@0 553 compressed data instead of a zlib wrapper. The gzip header will have no
michael@0 554 file name, no extra data, no comment, no modification time (set to zero), no
michael@0 555 header crc, and the operating system will be set to 255 (unknown). If a
michael@0 556 gzip stream is being written, strm->adler is a crc32 instead of an adler32.
michael@0 557
michael@0 558 The memLevel parameter specifies how much memory should be allocated
michael@0 559 for the internal compression state. memLevel=1 uses minimum memory but is
michael@0 560 slow and reduces compression ratio; memLevel=9 uses maximum memory for
michael@0 561 optimal speed. The default value is 8. See zconf.h for total memory usage
michael@0 562 as a function of windowBits and memLevel.
michael@0 563
michael@0 564 The strategy parameter is used to tune the compression algorithm. Use the
michael@0 565 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
michael@0 566 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
michael@0 567 string match), or Z_RLE to limit match distances to one (run-length
michael@0 568 encoding). Filtered data consists mostly of small values with a somewhat
michael@0 569 random distribution. In this case, the compression algorithm is tuned to
michael@0 570 compress them better. The effect of Z_FILTERED is to force more Huffman
michael@0 571 coding and less string matching; it is somewhat intermediate between
michael@0 572 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
michael@0 573 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
michael@0 574 strategy parameter only affects the compression ratio but not the
michael@0 575 correctness of the compressed output even if it is not set appropriately.
michael@0 576 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
michael@0 577 decoder for special applications.
michael@0 578
michael@0 579 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
michael@0 580 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
michael@0 581 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
michael@0 582 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
michael@0 583 set to null if there is no error message. deflateInit2 does not perform any
michael@0 584 compression: this will be done by deflate().
michael@0 585 */
michael@0 586
michael@0 587 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
michael@0 588 const Bytef *dictionary,
michael@0 589 uInt dictLength));
michael@0 590 /*
michael@0 591 Initializes the compression dictionary from the given byte sequence
michael@0 592 without producing any compressed output. When using the zlib format, this
michael@0 593 function must be called immediately after deflateInit, deflateInit2 or
michael@0 594 deflateReset, and before any call of deflate. When doing raw deflate, this
michael@0 595 function must be called either before any call of deflate, or immediately
michael@0 596 after the completion of a deflate block, i.e. after all input has been
michael@0 597 consumed and all output has been delivered when using any of the flush
michael@0 598 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The
michael@0 599 compressor and decompressor must use exactly the same dictionary (see
michael@0 600 inflateSetDictionary).
michael@0 601
michael@0 602 The dictionary should consist of strings (byte sequences) that are likely
michael@0 603 to be encountered later in the data to be compressed, with the most commonly
michael@0 604 used strings preferably put towards the end of the dictionary. Using a
michael@0 605 dictionary is most useful when the data to be compressed is short and can be
michael@0 606 predicted with good accuracy; the data can then be compressed better than
michael@0 607 with the default empty dictionary.
michael@0 608
michael@0 609 Depending on the size of the compression data structures selected by
michael@0 610 deflateInit or deflateInit2, a part of the dictionary may in effect be
michael@0 611 discarded, for example if the dictionary is larger than the window size
michael@0 612 provided in deflateInit or deflateInit2. Thus the strings most likely to be
michael@0 613 useful should be put at the end of the dictionary, not at the front. In
michael@0 614 addition, the current implementation of deflate will use at most the window
michael@0 615 size minus 262 bytes of the provided dictionary.
michael@0 616
michael@0 617 Upon return of this function, strm->adler is set to the adler32 value
michael@0 618 of the dictionary; the decompressor may later use this value to determine
michael@0 619 which dictionary has been used by the compressor. (The adler32 value
michael@0 620 applies to the whole dictionary even if only a subset of the dictionary is
michael@0 621 actually used by the compressor.) If a raw deflate was requested, then the
michael@0 622 adler32 value is not computed and strm->adler is not set.
michael@0 623
michael@0 624 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
michael@0 625 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
michael@0 626 inconsistent (for example if deflate has already been called for this stream
michael@0 627 or if not at a block boundary for raw deflate). deflateSetDictionary does
michael@0 628 not perform any compression: this will be done by deflate().
michael@0 629 */
michael@0 630
michael@0 631 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
michael@0 632 z_streamp source));
michael@0 633 /*
michael@0 634 Sets the destination stream as a complete copy of the source stream.
michael@0 635
michael@0 636 This function can be useful when several compression strategies will be
michael@0 637 tried, for example when there are several ways of pre-processing the input
michael@0 638 data with a filter. The streams that will be discarded should then be freed
michael@0 639 by calling deflateEnd. Note that deflateCopy duplicates the internal
michael@0 640 compression state which can be quite large, so this strategy is slow and can
michael@0 641 consume lots of memory.
michael@0 642
michael@0 643 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
michael@0 644 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
michael@0 645 (such as zalloc being Z_NULL). msg is left unchanged in both source and
michael@0 646 destination.
michael@0 647 */
michael@0 648
michael@0 649 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
michael@0 650 /*
michael@0 651 This function is equivalent to deflateEnd followed by deflateInit,
michael@0 652 but does not free and reallocate all the internal compression state. The
michael@0 653 stream will keep the same compression level and any other attributes that
michael@0 654 may have been set by deflateInit2.
michael@0 655
michael@0 656 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
michael@0 657 stream state was inconsistent (such as zalloc or state being Z_NULL).
michael@0 658 */
michael@0 659
michael@0 660 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
michael@0 661 int level,
michael@0 662 int strategy));
michael@0 663 /*
michael@0 664 Dynamically update the compression level and compression strategy. The
michael@0 665 interpretation of level and strategy is as in deflateInit2. This can be
michael@0 666 used to switch between compression and straight copy of the input data, or
michael@0 667 to switch to a different kind of input data requiring a different strategy.
michael@0 668 If the compression level is changed, the input available so far is
michael@0 669 compressed with the old level (and may be flushed); the new level will take
michael@0 670 effect only at the next call of deflate().
michael@0 671
michael@0 672 Before the call of deflateParams, the stream state must be set as for
michael@0 673 a call of deflate(), since the currently available input may have to be
michael@0 674 compressed and flushed. In particular, strm->avail_out must be non-zero.
michael@0 675
michael@0 676 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
michael@0 677 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
michael@0 678 strm->avail_out was zero.
michael@0 679 */
michael@0 680
michael@0 681 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
michael@0 682 int good_length,
michael@0 683 int max_lazy,
michael@0 684 int nice_length,
michael@0 685 int max_chain));
michael@0 686 /*
michael@0 687 Fine tune deflate's internal compression parameters. This should only be
michael@0 688 used by someone who understands the algorithm used by zlib's deflate for
michael@0 689 searching for the best matching string, and even then only by the most
michael@0 690 fanatic optimizer trying to squeeze out the last compressed bit for their
michael@0 691 specific input data. Read the deflate.c source code for the meaning of the
michael@0 692 max_lazy, good_length, nice_length, and max_chain parameters.
michael@0 693
michael@0 694 deflateTune() can be called after deflateInit() or deflateInit2(), and
michael@0 695 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
michael@0 696 */
michael@0 697
michael@0 698 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
michael@0 699 uLong sourceLen));
michael@0 700 /*
michael@0 701 deflateBound() returns an upper bound on the compressed size after
michael@0 702 deflation of sourceLen bytes. It must be called after deflateInit() or
michael@0 703 deflateInit2(), and after deflateSetHeader(), if used. This would be used
michael@0 704 to allocate an output buffer for deflation in a single pass, and so would be
michael@0 705 called before deflate(). If that first deflate() call is provided the
michael@0 706 sourceLen input bytes, an output buffer allocated to the size returned by
michael@0 707 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
michael@0 708 to return Z_STREAM_END. Note that it is possible for the compressed size to
michael@0 709 be larger than the value returned by deflateBound() if flush options other
michael@0 710 than Z_FINISH or Z_NO_FLUSH are used.
michael@0 711 */
michael@0 712
michael@0 713 ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
michael@0 714 unsigned *pending,
michael@0 715 int *bits));
michael@0 716 /*
michael@0 717 deflatePending() returns the number of bytes and bits of output that have
michael@0 718 been generated, but not yet provided in the available output. The bytes not
michael@0 719 provided would be due to the available output space having being consumed.
michael@0 720 The number of bits of output not provided are between 0 and 7, where they
michael@0 721 await more bits to join them in order to fill out a full byte. If pending
michael@0 722 or bits are Z_NULL, then those values are not set.
michael@0 723
michael@0 724 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
michael@0 725 stream state was inconsistent.
michael@0 726 */
michael@0 727
michael@0 728 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
michael@0 729 int bits,
michael@0 730 int value));
michael@0 731 /*
michael@0 732 deflatePrime() inserts bits in the deflate output stream. The intent
michael@0 733 is that this function is used to start off the deflate output with the bits
michael@0 734 leftover from a previous deflate stream when appending to it. As such, this
michael@0 735 function can only be used for raw deflate, and must be used before the first
michael@0 736 deflate() call after a deflateInit2() or deflateReset(). bits must be less
michael@0 737 than or equal to 16, and that many of the least significant bits of value
michael@0 738 will be inserted in the output.
michael@0 739
michael@0 740 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
michael@0 741 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
michael@0 742 source stream state was inconsistent.
michael@0 743 */
michael@0 744
michael@0 745 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
michael@0 746 gz_headerp head));
michael@0 747 /*
michael@0 748 deflateSetHeader() provides gzip header information for when a gzip
michael@0 749 stream is requested by deflateInit2(). deflateSetHeader() may be called
michael@0 750 after deflateInit2() or deflateReset() and before the first call of
michael@0 751 deflate(). The text, time, os, extra field, name, and comment information
michael@0 752 in the provided gz_header structure are written to the gzip header (xflag is
michael@0 753 ignored -- the extra flags are set according to the compression level). The
michael@0 754 caller must assure that, if not Z_NULL, name and comment are terminated with
michael@0 755 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
michael@0 756 available there. If hcrc is true, a gzip header crc is included. Note that
michael@0 757 the current versions of the command-line version of gzip (up through version
michael@0 758 1.3.x) do not support header crc's, and will report that it is a "multi-part
michael@0 759 gzip file" and give up.
michael@0 760
michael@0 761 If deflateSetHeader is not used, the default gzip header has text false,
michael@0 762 the time set to zero, and os set to 255, with no extra, name, or comment
michael@0 763 fields. The gzip header is returned to the default state by deflateReset().
michael@0 764
michael@0 765 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
michael@0 766 stream state was inconsistent.
michael@0 767 */
michael@0 768
michael@0 769 /*
michael@0 770 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
michael@0 771 int windowBits));
michael@0 772
michael@0 773 This is another version of inflateInit with an extra parameter. The
michael@0 774 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
michael@0 775 before by the caller.
michael@0 776
michael@0 777 The windowBits parameter is the base two logarithm of the maximum window
michael@0 778 size (the size of the history buffer). It should be in the range 8..15 for
michael@0 779 this version of the library. The default value is 15 if inflateInit is used
michael@0 780 instead. windowBits must be greater than or equal to the windowBits value
michael@0 781 provided to deflateInit2() while compressing, or it must be equal to 15 if
michael@0 782 deflateInit2() was not used. If a compressed stream with a larger window
michael@0 783 size is given as input, inflate() will return with the error code
michael@0 784 Z_DATA_ERROR instead of trying to allocate a larger window.
michael@0 785
michael@0 786 windowBits can also be zero to request that inflate use the window size in
michael@0 787 the zlib header of the compressed stream.
michael@0 788
michael@0 789 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
michael@0 790 determines the window size. inflate() will then process raw deflate data,
michael@0 791 not looking for a zlib or gzip header, not generating a check value, and not
michael@0 792 looking for any check values for comparison at the end of the stream. This
michael@0 793 is for use with other formats that use the deflate compressed data format
michael@0 794 such as zip. Those formats provide their own check values. If a custom
michael@0 795 format is developed using the raw deflate format for compressed data, it is
michael@0 796 recommended that a check value such as an adler32 or a crc32 be applied to
michael@0 797 the uncompressed data as is done in the zlib, gzip, and zip formats. For
michael@0 798 most applications, the zlib format should be used as is. Note that comments
michael@0 799 above on the use in deflateInit2() applies to the magnitude of windowBits.
michael@0 800
michael@0 801 windowBits can also be greater than 15 for optional gzip decoding. Add
michael@0 802 32 to windowBits to enable zlib and gzip decoding with automatic header
michael@0 803 detection, or add 16 to decode only the gzip format (the zlib format will
michael@0 804 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
michael@0 805 crc32 instead of an adler32.
michael@0 806
michael@0 807 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
michael@0 808 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
michael@0 809 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
michael@0 810 invalid, such as a null pointer to the structure. msg is set to null if
michael@0 811 there is no error message. inflateInit2 does not perform any decompression
michael@0 812 apart from possibly reading the zlib header if present: actual decompression
michael@0 813 will be done by inflate(). (So next_in and avail_in may be modified, but
michael@0 814 next_out and avail_out are unused and unchanged.) The current implementation
michael@0 815 of inflateInit2() does not process any header information -- that is
michael@0 816 deferred until inflate() is called.
michael@0 817 */
michael@0 818
michael@0 819 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
michael@0 820 const Bytef *dictionary,
michael@0 821 uInt dictLength));
michael@0 822 /*
michael@0 823 Initializes the decompression dictionary from the given uncompressed byte
michael@0 824 sequence. This function must be called immediately after a call of inflate,
michael@0 825 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
michael@0 826 can be determined from the adler32 value returned by that call of inflate.
michael@0 827 The compressor and decompressor must use exactly the same dictionary (see
michael@0 828 deflateSetDictionary). For raw inflate, this function can be called at any
michael@0 829 time to set the dictionary. If the provided dictionary is smaller than the
michael@0 830 window and there is already data in the window, then the provided dictionary
michael@0 831 will amend what's there. The application must insure that the dictionary
michael@0 832 that was used for compression is provided.
michael@0 833
michael@0 834 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
michael@0 835 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
michael@0 836 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
michael@0 837 expected one (incorrect adler32 value). inflateSetDictionary does not
michael@0 838 perform any decompression: this will be done by subsequent calls of
michael@0 839 inflate().
michael@0 840 */
michael@0 841
michael@0 842 ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
michael@0 843 Bytef *dictionary,
michael@0 844 uInt *dictLength));
michael@0 845 /*
michael@0 846 Returns the sliding dictionary being maintained by inflate. dictLength is
michael@0 847 set to the number of bytes in the dictionary, and that many bytes are copied
michael@0 848 to dictionary. dictionary must have enough space, where 32768 bytes is
michael@0 849 always enough. If inflateGetDictionary() is called with dictionary equal to
michael@0 850 Z_NULL, then only the dictionary length is returned, and nothing is copied.
michael@0 851 Similary, if dictLength is Z_NULL, then it is not set.
michael@0 852
michael@0 853 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
michael@0 854 stream state is inconsistent.
michael@0 855 */
michael@0 856
michael@0 857 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
michael@0 858 /*
michael@0 859 Skips invalid compressed data until a possible full flush point (see above
michael@0 860 for the description of deflate with Z_FULL_FLUSH) can be found, or until all
michael@0 861 available input is skipped. No output is provided.
michael@0 862
michael@0 863 inflateSync searches for a 00 00 FF FF pattern in the compressed data.
michael@0 864 All full flush points have this pattern, but not all occurrences of this
michael@0 865 pattern are full flush points.
michael@0 866
michael@0 867 inflateSync returns Z_OK if a possible full flush point has been found,
michael@0 868 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
michael@0 869 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
michael@0 870 In the success case, the application may save the current current value of
michael@0 871 total_in which indicates where valid compressed data was found. In the
michael@0 872 error case, the application may repeatedly call inflateSync, providing more
michael@0 873 input each time, until success or end of the input data.
michael@0 874 */
michael@0 875
michael@0 876 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
michael@0 877 z_streamp source));
michael@0 878 /*
michael@0 879 Sets the destination stream as a complete copy of the source stream.
michael@0 880
michael@0 881 This function can be useful when randomly accessing a large stream. The
michael@0 882 first pass through the stream can periodically record the inflate state,
michael@0 883 allowing restarting inflate at those points when randomly accessing the
michael@0 884 stream.
michael@0 885
michael@0 886 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
michael@0 887 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
michael@0 888 (such as zalloc being Z_NULL). msg is left unchanged in both source and
michael@0 889 destination.
michael@0 890 */
michael@0 891
michael@0 892 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
michael@0 893 /*
michael@0 894 This function is equivalent to inflateEnd followed by inflateInit,
michael@0 895 but does not free and reallocate all the internal decompression state. The
michael@0 896 stream will keep attributes that may have been set by inflateInit2.
michael@0 897
michael@0 898 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
michael@0 899 stream state was inconsistent (such as zalloc or state being Z_NULL).
michael@0 900 */
michael@0 901
michael@0 902 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
michael@0 903 int windowBits));
michael@0 904 /*
michael@0 905 This function is the same as inflateReset, but it also permits changing
michael@0 906 the wrap and window size requests. The windowBits parameter is interpreted
michael@0 907 the same as it is for inflateInit2.
michael@0 908
michael@0 909 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
michael@0 910 stream state was inconsistent (such as zalloc or state being Z_NULL), or if
michael@0 911 the windowBits parameter is invalid.
michael@0 912 */
michael@0 913
michael@0 914 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
michael@0 915 int bits,
michael@0 916 int value));
michael@0 917 /*
michael@0 918 This function inserts bits in the inflate input stream. The intent is
michael@0 919 that this function is used to start inflating at a bit position in the
michael@0 920 middle of a byte. The provided bits will be used before any bytes are used
michael@0 921 from next_in. This function should only be used with raw inflate, and
michael@0 922 should be used before the first inflate() call after inflateInit2() or
michael@0 923 inflateReset(). bits must be less than or equal to 16, and that many of the
michael@0 924 least significant bits of value will be inserted in the input.
michael@0 925
michael@0 926 If bits is negative, then the input stream bit buffer is emptied. Then
michael@0 927 inflatePrime() can be called again to put bits in the buffer. This is used
michael@0 928 to clear out bits leftover after feeding inflate a block description prior
michael@0 929 to feeding inflate codes.
michael@0 930
michael@0 931 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
michael@0 932 stream state was inconsistent.
michael@0 933 */
michael@0 934
michael@0 935 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
michael@0 936 /*
michael@0 937 This function returns two values, one in the lower 16 bits of the return
michael@0 938 value, and the other in the remaining upper bits, obtained by shifting the
michael@0 939 return value down 16 bits. If the upper value is -1 and the lower value is
michael@0 940 zero, then inflate() is currently decoding information outside of a block.
michael@0 941 If the upper value is -1 and the lower value is non-zero, then inflate is in
michael@0 942 the middle of a stored block, with the lower value equaling the number of
michael@0 943 bytes from the input remaining to copy. If the upper value is not -1, then
michael@0 944 it is the number of bits back from the current bit position in the input of
michael@0 945 the code (literal or length/distance pair) currently being processed. In
michael@0 946 that case the lower value is the number of bytes already emitted for that
michael@0 947 code.
michael@0 948
michael@0 949 A code is being processed if inflate is waiting for more input to complete
michael@0 950 decoding of the code, or if it has completed decoding but is waiting for
michael@0 951 more output space to write the literal or match data.
michael@0 952
michael@0 953 inflateMark() is used to mark locations in the input data for random
michael@0 954 access, which may be at bit positions, and to note those cases where the
michael@0 955 output of a code may span boundaries of random access blocks. The current
michael@0 956 location in the input stream can be determined from avail_in and data_type
michael@0 957 as noted in the description for the Z_BLOCK flush parameter for inflate.
michael@0 958
michael@0 959 inflateMark returns the value noted above or -1 << 16 if the provided
michael@0 960 source stream state was inconsistent.
michael@0 961 */
michael@0 962
michael@0 963 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
michael@0 964 gz_headerp head));
michael@0 965 /*
michael@0 966 inflateGetHeader() requests that gzip header information be stored in the
michael@0 967 provided gz_header structure. inflateGetHeader() may be called after
michael@0 968 inflateInit2() or inflateReset(), and before the first call of inflate().
michael@0 969 As inflate() processes the gzip stream, head->done is zero until the header
michael@0 970 is completed, at which time head->done is set to one. If a zlib stream is
michael@0 971 being decoded, then head->done is set to -1 to indicate that there will be
michael@0 972 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
michael@0 973 used to force inflate() to return immediately after header processing is
michael@0 974 complete and before any actual data is decompressed.
michael@0 975
michael@0 976 The text, time, xflags, and os fields are filled in with the gzip header
michael@0 977 contents. hcrc is set to true if there is a header CRC. (The header CRC
michael@0 978 was valid if done is set to one.) If extra is not Z_NULL, then extra_max
michael@0 979 contains the maximum number of bytes to write to extra. Once done is true,
michael@0 980 extra_len contains the actual extra field length, and extra contains the
michael@0 981 extra field, or that field truncated if extra_max is less than extra_len.
michael@0 982 If name is not Z_NULL, then up to name_max characters are written there,
michael@0 983 terminated with a zero unless the length is greater than name_max. If
michael@0 984 comment is not Z_NULL, then up to comm_max characters are written there,
michael@0 985 terminated with a zero unless the length is greater than comm_max. When any
michael@0 986 of extra, name, or comment are not Z_NULL and the respective field is not
michael@0 987 present in the header, then that field is set to Z_NULL to signal its
michael@0 988 absence. This allows the use of deflateSetHeader() with the returned
michael@0 989 structure to duplicate the header. However if those fields are set to
michael@0 990 allocated memory, then the application will need to save those pointers
michael@0 991 elsewhere so that they can be eventually freed.
michael@0 992
michael@0 993 If inflateGetHeader is not used, then the header information is simply
michael@0 994 discarded. The header is always checked for validity, including the header
michael@0 995 CRC if present. inflateReset() will reset the process to discard the header
michael@0 996 information. The application would need to call inflateGetHeader() again to
michael@0 997 retrieve the header from the next gzip stream.
michael@0 998
michael@0 999 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
michael@0 1000 stream state was inconsistent.
michael@0 1001 */
michael@0 1002
michael@0 1003 /*
michael@0 1004 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
michael@0 1005 unsigned char FAR *window));
michael@0 1006
michael@0 1007 Initialize the internal stream state for decompression using inflateBack()
michael@0 1008 calls. The fields zalloc, zfree and opaque in strm must be initialized
michael@0 1009 before the call. If zalloc and zfree are Z_NULL, then the default library-
michael@0 1010 derived memory allocation routines are used. windowBits is the base two
michael@0 1011 logarithm of the window size, in the range 8..15. window is a caller
michael@0 1012 supplied buffer of that size. Except for special applications where it is
michael@0 1013 assured that deflate was used with small window sizes, windowBits must be 15
michael@0 1014 and a 32K byte window must be supplied to be able to decompress general
michael@0 1015 deflate streams.
michael@0 1016
michael@0 1017 See inflateBack() for the usage of these routines.
michael@0 1018
michael@0 1019 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
michael@0 1020 the parameters are invalid, Z_MEM_ERROR if the internal state could not be
michael@0 1021 allocated, or Z_VERSION_ERROR if the version of the library does not match
michael@0 1022 the version of the header file.
michael@0 1023 */
michael@0 1024
michael@0 1025 typedef unsigned (*in_func) OF((void FAR *,
michael@0 1026 z_const unsigned char FAR * FAR *));
michael@0 1027 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
michael@0 1028
michael@0 1029 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
michael@0 1030 in_func in, void FAR *in_desc,
michael@0 1031 out_func out, void FAR *out_desc));
michael@0 1032 /*
michael@0 1033 inflateBack() does a raw inflate with a single call using a call-back
michael@0 1034 interface for input and output. This is potentially more efficient than
michael@0 1035 inflate() for file i/o applications, in that it avoids copying between the
michael@0 1036 output and the sliding window by simply making the window itself the output
michael@0 1037 buffer. inflate() can be faster on modern CPUs when used with large
michael@0 1038 buffers. inflateBack() trusts the application to not change the output
michael@0 1039 buffer passed by the output function, at least until inflateBack() returns.
michael@0 1040
michael@0 1041 inflateBackInit() must be called first to allocate the internal state
michael@0 1042 and to initialize the state with the user-provided window buffer.
michael@0 1043 inflateBack() may then be used multiple times to inflate a complete, raw
michael@0 1044 deflate stream with each call. inflateBackEnd() is then called to free the
michael@0 1045 allocated state.
michael@0 1046
michael@0 1047 A raw deflate stream is one with no zlib or gzip header or trailer.
michael@0 1048 This routine would normally be used in a utility that reads zip or gzip
michael@0 1049 files and writes out uncompressed files. The utility would decode the
michael@0 1050 header and process the trailer on its own, hence this routine expects only
michael@0 1051 the raw deflate stream to decompress. This is different from the normal
michael@0 1052 behavior of inflate(), which expects either a zlib or gzip header and
michael@0 1053 trailer around the deflate stream.
michael@0 1054
michael@0 1055 inflateBack() uses two subroutines supplied by the caller that are then
michael@0 1056 called by inflateBack() for input and output. inflateBack() calls those
michael@0 1057 routines until it reads a complete deflate stream and writes out all of the
michael@0 1058 uncompressed data, or until it encounters an error. The function's
michael@0 1059 parameters and return types are defined above in the in_func and out_func
michael@0 1060 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
michael@0 1061 number of bytes of provided input, and a pointer to that input in buf. If
michael@0 1062 there is no input available, in() must return zero--buf is ignored in that
michael@0 1063 case--and inflateBack() will return a buffer error. inflateBack() will call
michael@0 1064 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
michael@0 1065 should return zero on success, or non-zero on failure. If out() returns
michael@0 1066 non-zero, inflateBack() will return with an error. Neither in() nor out()
michael@0 1067 are permitted to change the contents of the window provided to
michael@0 1068 inflateBackInit(), which is also the buffer that out() uses to write from.
michael@0 1069 The length written by out() will be at most the window size. Any non-zero
michael@0 1070 amount of input may be provided by in().
michael@0 1071
michael@0 1072 For convenience, inflateBack() can be provided input on the first call by
michael@0 1073 setting strm->next_in and strm->avail_in. If that input is exhausted, then
michael@0 1074 in() will be called. Therefore strm->next_in must be initialized before
michael@0 1075 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
michael@0 1076 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
michael@0 1077 must also be initialized, and then if strm->avail_in is not zero, input will
michael@0 1078 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
michael@0 1079
michael@0 1080 The in_desc and out_desc parameters of inflateBack() is passed as the
michael@0 1081 first parameter of in() and out() respectively when they are called. These
michael@0 1082 descriptors can be optionally used to pass any information that the caller-
michael@0 1083 supplied in() and out() functions need to do their job.
michael@0 1084
michael@0 1085 On return, inflateBack() will set strm->next_in and strm->avail_in to
michael@0 1086 pass back any unused input that was provided by the last in() call. The
michael@0 1087 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
michael@0 1088 if in() or out() returned an error, Z_DATA_ERROR if there was a format error
michael@0 1089 in the deflate stream (in which case strm->msg is set to indicate the nature
michael@0 1090 of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
michael@0 1091 In the case of Z_BUF_ERROR, an input or output error can be distinguished
michael@0 1092 using strm->next_in which will be Z_NULL only if in() returned an error. If
michael@0 1093 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
michael@0 1094 non-zero. (in() will always be called before out(), so strm->next_in is
michael@0 1095 assured to be defined if out() returns non-zero.) Note that inflateBack()
michael@0 1096 cannot return Z_OK.
michael@0 1097 */
michael@0 1098
michael@0 1099 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
michael@0 1100 /*
michael@0 1101 All memory allocated by inflateBackInit() is freed.
michael@0 1102
michael@0 1103 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
michael@0 1104 state was inconsistent.
michael@0 1105 */
michael@0 1106
michael@0 1107 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
michael@0 1108 /* Return flags indicating compile-time options.
michael@0 1109
michael@0 1110 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
michael@0 1111 1.0: size of uInt
michael@0 1112 3.2: size of uLong
michael@0 1113 5.4: size of voidpf (pointer)
michael@0 1114 7.6: size of z_off_t
michael@0 1115
michael@0 1116 Compiler, assembler, and debug options:
michael@0 1117 8: DEBUG
michael@0 1118 9: ASMV or ASMINF -- use ASM code
michael@0 1119 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
michael@0 1120 11: 0 (reserved)
michael@0 1121
michael@0 1122 One-time table building (smaller code, but not thread-safe if true):
michael@0 1123 12: BUILDFIXED -- build static block decoding tables when needed
michael@0 1124 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
michael@0 1125 14,15: 0 (reserved)
michael@0 1126
michael@0 1127 Library content (indicates missing functionality):
michael@0 1128 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
michael@0 1129 deflate code when not needed)
michael@0 1130 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
michael@0 1131 and decode gzip streams (to avoid linking crc code)
michael@0 1132 18-19: 0 (reserved)
michael@0 1133
michael@0 1134 Operation variations (changes in library functionality):
michael@0 1135 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
michael@0 1136 21: FASTEST -- deflate algorithm with only one, lowest compression level
michael@0 1137 22,23: 0 (reserved)
michael@0 1138
michael@0 1139 The sprintf variant used by gzprintf (zero is best):
michael@0 1140 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
michael@0 1141 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
michael@0 1142 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
michael@0 1143
michael@0 1144 Remainder:
michael@0 1145 27-31: 0 (reserved)
michael@0 1146 */
michael@0 1147
michael@0 1148 #ifndef Z_SOLO
michael@0 1149
michael@0 1150 /* utility functions */
michael@0 1151
michael@0 1152 /*
michael@0 1153 The following utility functions are implemented on top of the basic
michael@0 1154 stream-oriented functions. To simplify the interface, some default options
michael@0 1155 are assumed (compression level and memory usage, standard memory allocation
michael@0 1156 functions). The source code of these utility functions can be modified if
michael@0 1157 you need special options.
michael@0 1158 */
michael@0 1159
michael@0 1160 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
michael@0 1161 const Bytef *source, uLong sourceLen));
michael@0 1162 /*
michael@0 1163 Compresses the source buffer into the destination buffer. sourceLen is
michael@0 1164 the byte length of the source buffer. Upon entry, destLen is the total size
michael@0 1165 of the destination buffer, which must be at least the value returned by
michael@0 1166 compressBound(sourceLen). Upon exit, destLen is the actual size of the
michael@0 1167 compressed buffer.
michael@0 1168
michael@0 1169 compress returns Z_OK if success, Z_MEM_ERROR if there was not
michael@0 1170 enough memory, Z_BUF_ERROR if there was not enough room in the output
michael@0 1171 buffer.
michael@0 1172 */
michael@0 1173
michael@0 1174 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
michael@0 1175 const Bytef *source, uLong sourceLen,
michael@0 1176 int level));
michael@0 1177 /*
michael@0 1178 Compresses the source buffer into the destination buffer. The level
michael@0 1179 parameter has the same meaning as in deflateInit. sourceLen is the byte
michael@0 1180 length of the source buffer. Upon entry, destLen is the total size of the
michael@0 1181 destination buffer, which must be at least the value returned by
michael@0 1182 compressBound(sourceLen). Upon exit, destLen is the actual size of the
michael@0 1183 compressed buffer.
michael@0 1184
michael@0 1185 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
michael@0 1186 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
michael@0 1187 Z_STREAM_ERROR if the level parameter is invalid.
michael@0 1188 */
michael@0 1189
michael@0 1190 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
michael@0 1191 /*
michael@0 1192 compressBound() returns an upper bound on the compressed size after
michael@0 1193 compress() or compress2() on sourceLen bytes. It would be used before a
michael@0 1194 compress() or compress2() call to allocate the destination buffer.
michael@0 1195 */
michael@0 1196
michael@0 1197 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
michael@0 1198 const Bytef *source, uLong sourceLen));
michael@0 1199 /*
michael@0 1200 Decompresses the source buffer into the destination buffer. sourceLen is
michael@0 1201 the byte length of the source buffer. Upon entry, destLen is the total size
michael@0 1202 of the destination buffer, which must be large enough to hold the entire
michael@0 1203 uncompressed data. (The size of the uncompressed data must have been saved
michael@0 1204 previously by the compressor and transmitted to the decompressor by some
michael@0 1205 mechanism outside the scope of this compression library.) Upon exit, destLen
michael@0 1206 is the actual size of the uncompressed buffer.
michael@0 1207
michael@0 1208 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
michael@0 1209 enough memory, Z_BUF_ERROR if there was not enough room in the output
michael@0 1210 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In
michael@0 1211 the case where there is not enough room, uncompress() will fill the output
michael@0 1212 buffer with the uncompressed data up to that point.
michael@0 1213 */
michael@0 1214
michael@0 1215 /* gzip file access functions */
michael@0 1216
michael@0 1217 /*
michael@0 1218 This library supports reading and writing files in gzip (.gz) format with
michael@0 1219 an interface similar to that of stdio, using the functions that start with
michael@0 1220 "gz". The gzip format is different from the zlib format. gzip is a gzip
michael@0 1221 wrapper, documented in RFC 1952, wrapped around a deflate stream.
michael@0 1222 */
michael@0 1223
michael@0 1224 typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
michael@0 1225
michael@0 1226 /*
michael@0 1227 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
michael@0 1228
michael@0 1229 Opens a gzip (.gz) file for reading or writing. The mode parameter is as
michael@0 1230 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
michael@0 1231 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
michael@0 1232 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
michael@0 1233 for fixed code compression as in "wb9F". (See the description of
michael@0 1234 deflateInit2 for more information about the strategy parameter.) 'T' will
michael@0 1235 request transparent writing or appending with no compression and not using
michael@0 1236 the gzip format.
michael@0 1237
michael@0 1238 "a" can be used instead of "w" to request that the gzip stream that will
michael@0 1239 be written be appended to the file. "+" will result in an error, since
michael@0 1240 reading and writing to the same gzip file is not supported. The addition of
michael@0 1241 "x" when writing will create the file exclusively, which fails if the file
michael@0 1242 already exists. On systems that support it, the addition of "e" when
michael@0 1243 reading or writing will set the flag to close the file on an execve() call.
michael@0 1244
michael@0 1245 These functions, as well as gzip, will read and decode a sequence of gzip
michael@0 1246 streams in a file. The append function of gzopen() can be used to create
michael@0 1247 such a file. (Also see gzflush() for another way to do this.) When
michael@0 1248 appending, gzopen does not test whether the file begins with a gzip stream,
michael@0 1249 nor does it look for the end of the gzip streams to begin appending. gzopen
michael@0 1250 will simply append a gzip stream to the existing file.
michael@0 1251
michael@0 1252 gzopen can be used to read a file which is not in gzip format; in this
michael@0 1253 case gzread will directly read from the file without decompression. When
michael@0 1254 reading, this will be detected automatically by looking for the magic two-
michael@0 1255 byte gzip header.
michael@0 1256
michael@0 1257 gzopen returns NULL if the file could not be opened, if there was
michael@0 1258 insufficient memory to allocate the gzFile state, or if an invalid mode was
michael@0 1259 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
michael@0 1260 errno can be checked to determine if the reason gzopen failed was that the
michael@0 1261 file could not be opened.
michael@0 1262 */
michael@0 1263
michael@0 1264 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
michael@0 1265 /*
michael@0 1266 gzdopen associates a gzFile with the file descriptor fd. File descriptors
michael@0 1267 are obtained from calls like open, dup, creat, pipe or fileno (if the file
michael@0 1268 has been previously opened with fopen). The mode parameter is as in gzopen.
michael@0 1269
michael@0 1270 The next call of gzclose on the returned gzFile will also close the file
michael@0 1271 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
michael@0 1272 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
michael@0 1273 mode);. The duplicated descriptor should be saved to avoid a leak, since
michael@0 1274 gzdopen does not close fd if it fails. If you are using fileno() to get the
michael@0 1275 file descriptor from a FILE *, then you will have to use dup() to avoid
michael@0 1276 double-close()ing the file descriptor. Both gzclose() and fclose() will
michael@0 1277 close the associated file descriptor, so they need to have different file
michael@0 1278 descriptors.
michael@0 1279
michael@0 1280 gzdopen returns NULL if there was insufficient memory to allocate the
michael@0 1281 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
michael@0 1282 provided, or '+' was provided), or if fd is -1. The file descriptor is not
michael@0 1283 used until the next gz* read, write, seek, or close operation, so gzdopen
michael@0 1284 will not detect if fd is invalid (unless fd is -1).
michael@0 1285 */
michael@0 1286
michael@0 1287 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
michael@0 1288 /*
michael@0 1289 Set the internal buffer size used by this library's functions. The
michael@0 1290 default buffer size is 8192 bytes. This function must be called after
michael@0 1291 gzopen() or gzdopen(), and before any other calls that read or write the
michael@0 1292 file. The buffer memory allocation is always deferred to the first read or
michael@0 1293 write. Two buffers are allocated, either both of the specified size when
michael@0 1294 writing, or one of the specified size and the other twice that size when
michael@0 1295 reading. A larger buffer size of, for example, 64K or 128K bytes will
michael@0 1296 noticeably increase the speed of decompression (reading).
michael@0 1297
michael@0 1298 The new buffer size also affects the maximum length for gzprintf().
michael@0 1299
michael@0 1300 gzbuffer() returns 0 on success, or -1 on failure, such as being called
michael@0 1301 too late.
michael@0 1302 */
michael@0 1303
michael@0 1304 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
michael@0 1305 /*
michael@0 1306 Dynamically update the compression level or strategy. See the description
michael@0 1307 of deflateInit2 for the meaning of these parameters.
michael@0 1308
michael@0 1309 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
michael@0 1310 opened for writing.
michael@0 1311 */
michael@0 1312
michael@0 1313 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
michael@0 1314 /*
michael@0 1315 Reads the given number of uncompressed bytes from the compressed file. If
michael@0 1316 the input file is not in gzip format, gzread copies the given number of
michael@0 1317 bytes into the buffer directly from the file.
michael@0 1318
michael@0 1319 After reaching the end of a gzip stream in the input, gzread will continue
michael@0 1320 to read, looking for another gzip stream. Any number of gzip streams may be
michael@0 1321 concatenated in the input file, and will all be decompressed by gzread().
michael@0 1322 If something other than a gzip stream is encountered after a gzip stream,
michael@0 1323 that remaining trailing garbage is ignored (and no error is returned).
michael@0 1324
michael@0 1325 gzread can be used to read a gzip file that is being concurrently written.
michael@0 1326 Upon reaching the end of the input, gzread will return with the available
michael@0 1327 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
michael@0 1328 gzclearerr can be used to clear the end of file indicator in order to permit
michael@0 1329 gzread to be tried again. Z_OK indicates that a gzip stream was completed
michael@0 1330 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the
michael@0 1331 middle of a gzip stream. Note that gzread does not return -1 in the event
michael@0 1332 of an incomplete gzip stream. This error is deferred until gzclose(), which
michael@0 1333 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
michael@0 1334 stream. Alternatively, gzerror can be used before gzclose to detect this
michael@0 1335 case.
michael@0 1336
michael@0 1337 gzread returns the number of uncompressed bytes actually read, less than
michael@0 1338 len for end of file, or -1 for error.
michael@0 1339 */
michael@0 1340
michael@0 1341 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
michael@0 1342 voidpc buf, unsigned len));
michael@0 1343 /*
michael@0 1344 Writes the given number of uncompressed bytes into the compressed file.
michael@0 1345 gzwrite returns the number of uncompressed bytes written or 0 in case of
michael@0 1346 error.
michael@0 1347 */
michael@0 1348
michael@0 1349 ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
michael@0 1350 /*
michael@0 1351 Converts, formats, and writes the arguments to the compressed file under
michael@0 1352 control of the format string, as in fprintf. gzprintf returns the number of
michael@0 1353 uncompressed bytes actually written, or 0 in case of error. The number of
michael@0 1354 uncompressed bytes written is limited to 8191, or one less than the buffer
michael@0 1355 size given to gzbuffer(). The caller should assure that this limit is not
michael@0 1356 exceeded. If it is exceeded, then gzprintf() will return an error (0) with
michael@0 1357 nothing written. In this case, there may also be a buffer overflow with
michael@0 1358 unpredictable consequences, which is possible only if zlib was compiled with
michael@0 1359 the insecure functions sprintf() or vsprintf() because the secure snprintf()
michael@0 1360 or vsnprintf() functions were not available. This can be determined using
michael@0 1361 zlibCompileFlags().
michael@0 1362 */
michael@0 1363
michael@0 1364 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
michael@0 1365 /*
michael@0 1366 Writes the given null-terminated string to the compressed file, excluding
michael@0 1367 the terminating null character.
michael@0 1368
michael@0 1369 gzputs returns the number of characters written, or -1 in case of error.
michael@0 1370 */
michael@0 1371
michael@0 1372 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
michael@0 1373 /*
michael@0 1374 Reads bytes from the compressed file until len-1 characters are read, or a
michael@0 1375 newline character is read and transferred to buf, or an end-of-file
michael@0 1376 condition is encountered. If any characters are read or if len == 1, the
michael@0 1377 string is terminated with a null character. If no characters are read due
michael@0 1378 to an end-of-file or len < 1, then the buffer is left untouched.
michael@0 1379
michael@0 1380 gzgets returns buf which is a null-terminated string, or it returns NULL
michael@0 1381 for end-of-file or in case of error. If there was an error, the contents at
michael@0 1382 buf are indeterminate.
michael@0 1383 */
michael@0 1384
michael@0 1385 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
michael@0 1386 /*
michael@0 1387 Writes c, converted to an unsigned char, into the compressed file. gzputc
michael@0 1388 returns the value that was written, or -1 in case of error.
michael@0 1389 */
michael@0 1390
michael@0 1391 ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
michael@0 1392 /*
michael@0 1393 Reads one byte from the compressed file. gzgetc returns this byte or -1
michael@0 1394 in case of end of file or error. This is implemented as a macro for speed.
michael@0 1395 As such, it does not do all of the checking the other functions do. I.e.
michael@0 1396 it does not check to see if file is NULL, nor whether the structure file
michael@0 1397 points to has been clobbered or not.
michael@0 1398 */
michael@0 1399
michael@0 1400 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
michael@0 1401 /*
michael@0 1402 Push one character back onto the stream to be read as the first character
michael@0 1403 on the next read. At least one character of push-back is allowed.
michael@0 1404 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
michael@0 1405 fail if c is -1, and may fail if a character has been pushed but not read
michael@0 1406 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
michael@0 1407 output buffer size of pushed characters is allowed. (See gzbuffer above.)
michael@0 1408 The pushed character will be discarded if the stream is repositioned with
michael@0 1409 gzseek() or gzrewind().
michael@0 1410 */
michael@0 1411
michael@0 1412 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
michael@0 1413 /*
michael@0 1414 Flushes all pending output into the compressed file. The parameter flush
michael@0 1415 is as in the deflate() function. The return value is the zlib error number
michael@0 1416 (see function gzerror below). gzflush is only permitted when writing.
michael@0 1417
michael@0 1418 If the flush parameter is Z_FINISH, the remaining data is written and the
michael@0 1419 gzip stream is completed in the output. If gzwrite() is called again, a new
michael@0 1420 gzip stream will be started in the output. gzread() is able to read such
michael@0 1421 concatented gzip streams.
michael@0 1422
michael@0 1423 gzflush should be called only when strictly necessary because it will
michael@0 1424 degrade compression if called too often.
michael@0 1425 */
michael@0 1426
michael@0 1427 /*
michael@0 1428 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
michael@0 1429 z_off_t offset, int whence));
michael@0 1430
michael@0 1431 Sets the starting position for the next gzread or gzwrite on the given
michael@0 1432 compressed file. The offset represents a number of bytes in the
michael@0 1433 uncompressed data stream. The whence parameter is defined as in lseek(2);
michael@0 1434 the value SEEK_END is not supported.
michael@0 1435
michael@0 1436 If the file is opened for reading, this function is emulated but can be
michael@0 1437 extremely slow. If the file is opened for writing, only forward seeks are
michael@0 1438 supported; gzseek then compresses a sequence of zeroes up to the new
michael@0 1439 starting position.
michael@0 1440
michael@0 1441 gzseek returns the resulting offset location as measured in bytes from
michael@0 1442 the beginning of the uncompressed stream, or -1 in case of error, in
michael@0 1443 particular if the file is opened for writing and the new starting position
michael@0 1444 would be before the current position.
michael@0 1445 */
michael@0 1446
michael@0 1447 ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
michael@0 1448 /*
michael@0 1449 Rewinds the given file. This function is supported only for reading.
michael@0 1450
michael@0 1451 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
michael@0 1452 */
michael@0 1453
michael@0 1454 /*
michael@0 1455 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
michael@0 1456
michael@0 1457 Returns the starting position for the next gzread or gzwrite on the given
michael@0 1458 compressed file. This position represents a number of bytes in the
michael@0 1459 uncompressed data stream, and is zero when starting, even if appending or
michael@0 1460 reading a gzip stream from the middle of a file using gzdopen().
michael@0 1461
michael@0 1462 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
michael@0 1463 */
michael@0 1464
michael@0 1465 /*
michael@0 1466 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
michael@0 1467
michael@0 1468 Returns the current offset in the file being read or written. This offset
michael@0 1469 includes the count of bytes that precede the gzip stream, for example when
michael@0 1470 appending or when using gzdopen() for reading. When reading, the offset
michael@0 1471 does not include as yet unused buffered input. This information can be used
michael@0 1472 for a progress indicator. On error, gzoffset() returns -1.
michael@0 1473 */
michael@0 1474
michael@0 1475 ZEXTERN int ZEXPORT gzeof OF((gzFile file));
michael@0 1476 /*
michael@0 1477 Returns true (1) if the end-of-file indicator has been set while reading,
michael@0 1478 false (0) otherwise. Note that the end-of-file indicator is set only if the
michael@0 1479 read tried to go past the end of the input, but came up short. Therefore,
michael@0 1480 just like feof(), gzeof() may return false even if there is no more data to
michael@0 1481 read, in the event that the last read request was for the exact number of
michael@0 1482 bytes remaining in the input file. This will happen if the input file size
michael@0 1483 is an exact multiple of the buffer size.
michael@0 1484
michael@0 1485 If gzeof() returns true, then the read functions will return no more data,
michael@0 1486 unless the end-of-file indicator is reset by gzclearerr() and the input file
michael@0 1487 has grown since the previous end of file was detected.
michael@0 1488 */
michael@0 1489
michael@0 1490 ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
michael@0 1491 /*
michael@0 1492 Returns true (1) if file is being copied directly while reading, or false
michael@0 1493 (0) if file is a gzip stream being decompressed.
michael@0 1494
michael@0 1495 If the input file is empty, gzdirect() will return true, since the input
michael@0 1496 does not contain a gzip stream.
michael@0 1497
michael@0 1498 If gzdirect() is used immediately after gzopen() or gzdopen() it will
michael@0 1499 cause buffers to be allocated to allow reading the file to determine if it
michael@0 1500 is a gzip file. Therefore if gzbuffer() is used, it should be called before
michael@0 1501 gzdirect().
michael@0 1502
michael@0 1503 When writing, gzdirect() returns true (1) if transparent writing was
michael@0 1504 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note:
michael@0 1505 gzdirect() is not needed when writing. Transparent writing must be
michael@0 1506 explicitly requested, so the application already knows the answer. When
michael@0 1507 linking statically, using gzdirect() will include all of the zlib code for
michael@0 1508 gzip file reading and decompression, which may not be desired.)
michael@0 1509 */
michael@0 1510
michael@0 1511 ZEXTERN int ZEXPORT gzclose OF((gzFile file));
michael@0 1512 /*
michael@0 1513 Flushes all pending output if necessary, closes the compressed file and
michael@0 1514 deallocates the (de)compression state. Note that once file is closed, you
michael@0 1515 cannot call gzerror with file, since its structures have been deallocated.
michael@0 1516 gzclose must not be called more than once on the same file, just as free
michael@0 1517 must not be called more than once on the same allocation.
michael@0 1518
michael@0 1519 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
michael@0 1520 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
michael@0 1521 last read ended in the middle of a gzip stream, or Z_OK on success.
michael@0 1522 */
michael@0 1523
michael@0 1524 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
michael@0 1525 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
michael@0 1526 /*
michael@0 1527 Same as gzclose(), but gzclose_r() is only for use when reading, and
michael@0 1528 gzclose_w() is only for use when writing or appending. The advantage to
michael@0 1529 using these instead of gzclose() is that they avoid linking in zlib
michael@0 1530 compression or decompression code that is not used when only reading or only
michael@0 1531 writing respectively. If gzclose() is used, then both compression and
michael@0 1532 decompression code will be included the application when linking to a static
michael@0 1533 zlib library.
michael@0 1534 */
michael@0 1535
michael@0 1536 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
michael@0 1537 /*
michael@0 1538 Returns the error message for the last error which occurred on the given
michael@0 1539 compressed file. errnum is set to zlib error number. If an error occurred
michael@0 1540 in the file system and not in the compression library, errnum is set to
michael@0 1541 Z_ERRNO and the application may consult errno to get the exact error code.
michael@0 1542
michael@0 1543 The application must not modify the returned string. Future calls to
michael@0 1544 this function may invalidate the previously returned string. If file is
michael@0 1545 closed, then the string previously returned by gzerror will no longer be
michael@0 1546 available.
michael@0 1547
michael@0 1548 gzerror() should be used to distinguish errors from end-of-file for those
michael@0 1549 functions above that do not distinguish those cases in their return values.
michael@0 1550 */
michael@0 1551
michael@0 1552 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
michael@0 1553 /*
michael@0 1554 Clears the error and end-of-file flags for file. This is analogous to the
michael@0 1555 clearerr() function in stdio. This is useful for continuing to read a gzip
michael@0 1556 file that is being written concurrently.
michael@0 1557 */
michael@0 1558
michael@0 1559 #endif /* !Z_SOLO */
michael@0 1560
michael@0 1561 /* checksum functions */
michael@0 1562
michael@0 1563 /*
michael@0 1564 These functions are not related to compression but are exported
michael@0 1565 anyway because they might be useful in applications using the compression
michael@0 1566 library.
michael@0 1567 */
michael@0 1568
michael@0 1569 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
michael@0 1570 /*
michael@0 1571 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
michael@0 1572 return the updated checksum. If buf is Z_NULL, this function returns the
michael@0 1573 required initial value for the checksum.
michael@0 1574
michael@0 1575 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
michael@0 1576 much faster.
michael@0 1577
michael@0 1578 Usage example:
michael@0 1579
michael@0 1580 uLong adler = adler32(0L, Z_NULL, 0);
michael@0 1581
michael@0 1582 while (read_buffer(buffer, length) != EOF) {
michael@0 1583 adler = adler32(adler, buffer, length);
michael@0 1584 }
michael@0 1585 if (adler != original_adler) error();
michael@0 1586 */
michael@0 1587
michael@0 1588 /*
michael@0 1589 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
michael@0 1590 z_off_t len2));
michael@0 1591
michael@0 1592 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
michael@0 1593 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
michael@0 1594 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
michael@0 1595 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note
michael@0 1596 that the z_off_t type (like off_t) is a signed integer. If len2 is
michael@0 1597 negative, the result has no meaning or utility.
michael@0 1598 */
michael@0 1599
michael@0 1600 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
michael@0 1601 /*
michael@0 1602 Update a running CRC-32 with the bytes buf[0..len-1] and return the
michael@0 1603 updated CRC-32. If buf is Z_NULL, this function returns the required
michael@0 1604 initial value for the crc. Pre- and post-conditioning (one's complement) is
michael@0 1605 performed within this function so it shouldn't be done by the application.
michael@0 1606
michael@0 1607 Usage example:
michael@0 1608
michael@0 1609 uLong crc = crc32(0L, Z_NULL, 0);
michael@0 1610
michael@0 1611 while (read_buffer(buffer, length) != EOF) {
michael@0 1612 crc = crc32(crc, buffer, length);
michael@0 1613 }
michael@0 1614 if (crc != original_crc) error();
michael@0 1615 */
michael@0 1616
michael@0 1617 /*
michael@0 1618 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
michael@0 1619
michael@0 1620 Combine two CRC-32 check values into one. For two sequences of bytes,
michael@0 1621 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
michael@0 1622 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
michael@0 1623 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
michael@0 1624 len2.
michael@0 1625 */
michael@0 1626
michael@0 1627
michael@0 1628 /* various hacks, don't look :) */
michael@0 1629
michael@0 1630 /* deflateInit and inflateInit are macros to allow checking the zlib version
michael@0 1631 * and the compiler's view of z_stream:
michael@0 1632 */
michael@0 1633 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
michael@0 1634 const char *version, int stream_size));
michael@0 1635 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
michael@0 1636 const char *version, int stream_size));
michael@0 1637 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
michael@0 1638 int windowBits, int memLevel,
michael@0 1639 int strategy, const char *version,
michael@0 1640 int stream_size));
michael@0 1641 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
michael@0 1642 const char *version, int stream_size));
michael@0 1643 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
michael@0 1644 unsigned char FAR *window,
michael@0 1645 const char *version,
michael@0 1646 int stream_size));
michael@0 1647 #define deflateInit(strm, level) \
michael@0 1648 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
michael@0 1649 #define inflateInit(strm) \
michael@0 1650 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
michael@0 1651 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
michael@0 1652 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
michael@0 1653 (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
michael@0 1654 #define inflateInit2(strm, windowBits) \
michael@0 1655 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
michael@0 1656 (int)sizeof(z_stream))
michael@0 1657 #define inflateBackInit(strm, windowBits, window) \
michael@0 1658 inflateBackInit_((strm), (windowBits), (window), \
michael@0 1659 ZLIB_VERSION, (int)sizeof(z_stream))
michael@0 1660
michael@0 1661 #ifndef Z_SOLO
michael@0 1662
michael@0 1663 /* gzgetc() macro and its supporting function and exposed data structure. Note
michael@0 1664 * that the real internal state is much larger than the exposed structure.
michael@0 1665 * This abbreviated structure exposes just enough for the gzgetc() macro. The
michael@0 1666 * user should not mess with these exposed elements, since their names or
michael@0 1667 * behavior could change in the future, perhaps even capriciously. They can
michael@0 1668 * only be used by the gzgetc() macro. You have been warned.
michael@0 1669 */
michael@0 1670 struct gzFile_s {
michael@0 1671 unsigned have;
michael@0 1672 unsigned char *next;
michael@0 1673 z_off64_t pos;
michael@0 1674 };
michael@0 1675 ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */
michael@0 1676 #ifdef Z_PREFIX_SET
michael@0 1677 # undef z_gzgetc
michael@0 1678 # define z_gzgetc(g) \
michael@0 1679 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
michael@0 1680 #else
michael@0 1681 # undef gzgetc
michael@0 1682 # define gzgetc(g) \
michael@0 1683 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
michael@0 1684 #endif
michael@0 1685
michael@0 1686 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
michael@0 1687 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
michael@0 1688 * both are true, the application gets the *64 functions, and the regular
michael@0 1689 * functions are changed to 64 bits) -- in case these are set on systems
michael@0 1690 * without large file support, _LFS64_LARGEFILE must also be true
michael@0 1691 */
michael@0 1692 #ifdef Z_LARGE64
michael@0 1693 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
michael@0 1694 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
michael@0 1695 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
michael@0 1696 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
michael@0 1697 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
michael@0 1698 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
michael@0 1699 #endif
michael@0 1700
michael@0 1701 #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
michael@0 1702 # ifdef Z_PREFIX_SET
michael@0 1703 # define z_gzopen z_gzopen64
michael@0 1704 # define z_gzseek z_gzseek64
michael@0 1705 # define z_gztell z_gztell64
michael@0 1706 # define z_gzoffset z_gzoffset64
michael@0 1707 # define z_adler32_combine z_adler32_combine64
michael@0 1708 # define z_crc32_combine z_crc32_combine64
michael@0 1709 # else
michael@0 1710 # define gzopen gzopen64
michael@0 1711 # define gzseek gzseek64
michael@0 1712 # define gztell gztell64
michael@0 1713 # define gzoffset gzoffset64
michael@0 1714 # define adler32_combine adler32_combine64
michael@0 1715 # define crc32_combine crc32_combine64
michael@0 1716 # endif
michael@0 1717 # ifndef Z_LARGE64
michael@0 1718 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
michael@0 1719 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
michael@0 1720 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
michael@0 1721 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
michael@0 1722 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
michael@0 1723 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
michael@0 1724 # endif
michael@0 1725 #else
michael@0 1726 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
michael@0 1727 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
michael@0 1728 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
michael@0 1729 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
michael@0 1730 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
michael@0 1731 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
michael@0 1732 #endif
michael@0 1733
michael@0 1734 #else /* Z_SOLO */
michael@0 1735
michael@0 1736 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
michael@0 1737 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
michael@0 1738
michael@0 1739 #endif /* !Z_SOLO */
michael@0 1740
michael@0 1741 /* hack for buggy compilers */
michael@0 1742 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
michael@0 1743 struct internal_state {int dummy;};
michael@0 1744 #endif
michael@0 1745
michael@0 1746 /* undocumented functions */
michael@0 1747 ZEXTERN const char * ZEXPORT zError OF((int));
michael@0 1748 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
michael@0 1749 ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void));
michael@0 1750 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
michael@0 1751 ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp));
michael@0 1752 ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp));
michael@0 1753 #if defined(_WIN32) && !defined(Z_SOLO)
michael@0 1754 ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path,
michael@0 1755 const char *mode));
michael@0 1756 #endif
michael@0 1757 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
michael@0 1758 # ifndef Z_SOLO
michael@0 1759 ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file,
michael@0 1760 const char *format,
michael@0 1761 va_list va));
michael@0 1762 # endif
michael@0 1763 #endif
michael@0 1764
michael@0 1765 #ifdef __cplusplus
michael@0 1766 }
michael@0 1767 #endif
michael@0 1768
michael@0 1769 #endif /* ZLIB_H */

mercurial