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Issue 1417483004: Remove duplicate core/include/thirdparties headers. (Closed) Base URL: https://pdfium.googlesource.com/pdfium.git@master
Patch Set: Created 5 years, 2 months ago
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1 /* zlib.h -- interface of the 'zlib' general purpose compression library
2 version 1.2.8, April 28th, 2013
3
4 Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
5
6 This software is provided 'as-is', without any express or implied
7 warranty. In no event will the authors be held liable for any damages
8 arising from the use of this software.
9
10 Permission is granted to anyone to use this software for any purpose,
11 including commercial applications, and to alter it and redistribute it
12 freely, subject to the following restrictions:
13
14 1. The origin of this software must not be misrepresented; you must not
15 claim that you wrote the original software. If you use this software
16 in a product, an acknowledgment in the product documentation would be
17 appreciated but is not required.
18 2. Altered source versions must be plainly marked as such, and must not be
19 misrepresented as being the original software.
20 3. This notice may not be removed or altered from any source distribution.
21
22 Jean-loup Gailly Mark Adler
23 jloup@gzip.org madler@alumni.caltech.edu
24
25
26 The data format used by the zlib library is described by RFCs (Request for
27 Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
28 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
29 */
30
31 #ifndef ZLIB_H
32 #define ZLIB_H
33
34 #define deflate_copyright FPDFAPI_deflate_copyright
35 #define adler32 FPDFAPI_adler32
36 #define compress2 FPDFAPI_compress2
37 #define compress FPDFAPI_compress
38 #define compressBound FPDFAPI_compressBound
39 #define get_crc_table FPDFAPI_get_crc_table
40 #define crc32 FPDFAPI_crc32
41 #define deflateInit_ FPDFAPI_deflateInit_
42 #define deflateInit2_ FPDFAPI_deflateInit2_
43 #define deflateSetDictionary FPDFAPI_deflateSetDictionary
44 #define deflateReset FPDFAPI_deflateReset
45 #define deflatePending FPDFAPI_deflatePending
46 #define deflatePrime FPDFAPI_deflatePrime
47 #define deflateParams FPDFAPI_deflateParams
48 #define deflateBound FPDFAPI_deflateBound
49 #define deflateSetHeader FPDFAPI_deflateSetHeader
50 #define deflateTune FPDFAPI_deflateTune
51 #define deflate FPDFAPI_deflate
52 #define deflateEnd FPDFAPI_deflateEnd
53 #define deflateCopy FPDFAPI_deflateCopy
54 #define inflateBackInit_ FPDFAPI_inflateBackInit_
55 #define inflateBack FPDFAPI_inflateBack
56 #define inflateBackEnd FPDFAPI_inflateBackEnd
57 #define inflateReset FPDFAPI_inflateReset
58 #define inflateInit2_ FPDFAPI_inflateInit2_
59 #define inflateInit_ FPDFAPI_inflateInit_
60 #define inflate FPDFAPI_inflate
61 #define inflateEnd FPDFAPI_inflateEnd
62 #define inflateSetDictionary FPDFAPI_inflateSetDictionary
63 #define inflateSync FPDFAPI_inflateSync
64 #define inflateSyncPoint FPDFAPI_inflateSyncPoint
65 #define inflateCopy FPDFAPI_inflateCopy
66 #define uncompress FPDFAPI_uncompress
67 #define zlibVersion FPDFAPI_zlibVersion
68 #define zlibCompileFlags FPDFAPI_zlibCompileFlags
69 #define zError FPDFAPI_zError
70 #define z_errmsg FPDFAPI_z_errmsg
71 #define zcfree FPDFAPI_zcfree
72 #define zcalloc FPDFAPI_zcalloc
73 #define inflate_fast FPDFAPI_inflate_fast
74 #define inflate_table FPDFAPI_inflate_table
75 #define inflate_copyright FPDFAPI_inflate_copyright
76 #define _length_code FPDFAPI_length_code
77 #define _tr_flush_block FPDFAPI_tr_flush_block
78 #define _dist_code FPDFAPI_dist_code
79 #define _tr_stored_block FPDFAPI_tr_stored_block
80 #define _tr_init FPDFAPI_tr_init
81 #define _tr_align FPDFAPI_tr_align
82 #define _tr_tally FPDFAPI_tr_tally
83 #define _tr_flush_bits FPDFAPI_tr_flush_bits
84 #define adler32_combine FPDFAPI_adler32_combine
85 #define inflatePrime FPDFAPI_inflatePrime
86 #define inflateGetDictionary FPDFAPI_inflateGetDictionary
87 #define inflateGetHeader FPDFAPI_inflateGetHeader
88 #define crc32_combine FPDFAPI_crc32_combine
89 #define inflateReset2 FPDFAPI_inflateReset2
90 #define inflateUndermine FPDFAPI_inflateUndermine
91 #define inflateMark FPDFAPI_inflateMark
92 #define adler32_combine64 FPDFAPI_adler32_combine64
93 #define inflateResetKeep FPDFAPI_inflateResetKeep
94 #define deflateResetKeep FPDFAPI_deflateResetKeep
95
96 #include "zconf.h"
97
98 /* Sunliang.Liu 20100908 sync the config to the old revision. NO_GZIP */
99 #define NO_GZIP /* XYQ */
100
101 #ifdef __cplusplus
102 extern "C" {
103 #endif
104
105 #define ZLIB_VERSION "1.2.8"
106 #define ZLIB_VERNUM 0x1280
107 #define ZLIB_VER_MAJOR 1
108 #define ZLIB_VER_MINOR 2
109 #define ZLIB_VER_REVISION 8
110 #define ZLIB_VER_SUBREVISION 0
111
112 /*
113 The 'zlib' compression library provides in-memory compression and
114 decompression functions, including integrity checks of the uncompressed data.
115 This version of the library supports only one compression method (deflation)
116 but other algorithms will be added later and will have the same stream
117 interface.
118
119 Compression can be done in a single step if the buffers are large enough,
120 or can be done by repeated calls of the compression function. In the latter
121 case, the application must provide more input and/or consume the output
122 (providing more output space) before each call.
123
124 The compressed data format used by default by the in-memory functions is
125 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
126 around a deflate stream, which is itself documented in RFC 1951.
127
128 The library also supports reading and writing files in gzip (.gz) format
129 with an interface similar to that of stdio using the functions that start
130 with "gz". The gzip format is different from the zlib format. gzip is a
131 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
132
133 This library can optionally read and write gzip streams in memory as well.
134
135 The zlib format was designed to be compact and fast for use in memory
136 and on communications channels. The gzip format was designed for single-
137 file compression on file systems, has a larger header than zlib to maintain
138 directory information, and uses a different, slower check method than zlib.
139
140 The library does not install any signal handler. The decoder checks
141 the consistency of the compressed data, so the library should never crash
142 even in case of corrupted input.
143 */
144
145 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
146 typedef void (*free_func) OF((voidpf opaque, voidpf address));
147
148 struct internal_state;
149
150 typedef struct z_stream_s {
151 z_const Bytef *next_in; /* next input byte */
152 uInt avail_in; /* number of bytes available at next_in */
153 uLong total_in; /* total number of input bytes read so far */
154
155 Bytef *next_out; /* next output byte should be put there */
156 uInt avail_out; /* remaining free space at next_out */
157 uLong total_out; /* total number of bytes output so far */
158
159 z_const char *msg; /* last error message, NULL if no error */
160 struct internal_state FAR *state; /* not visible by applications */
161
162 alloc_func zalloc; /* used to allocate the internal state */
163 free_func zfree; /* used to free the internal state */
164 voidpf opaque; /* private data object passed to zalloc and zfree */
165
166 int data_type; /* best guess about the data type: binary or text */
167 uLong adler; /* adler32 value of the uncompressed data */
168 uLong reserved; /* reserved for future use */
169 } z_stream;
170
171 typedef z_stream FAR *z_streamp;
172
173 /*
174 gzip header information passed to and from zlib routines. See RFC 1952
175 for more details on the meanings of these fields.
176 */
177 typedef struct gz_header_s {
178 int text; /* true if compressed data believed to be text */
179 uLong time; /* modification time */
180 int xflags; /* extra flags (not used when writing a gzip file) */
181 int os; /* operating system */
182 Bytef *extra; /* pointer to extra field or Z_NULL if none */
183 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
184 uInt extra_max; /* space at extra (only when reading header) */
185 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
186 uInt name_max; /* space at name (only when reading header) */
187 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
188 uInt comm_max; /* space at comment (only when reading header) */
189 int hcrc; /* true if there was or will be a header crc */
190 int done; /* true when done reading gzip header (not used
191 when writing a gzip file) */
192 } gz_header;
193
194 typedef gz_header FAR *gz_headerp;
195
196 /*
197 The application must update next_in and avail_in when avail_in has dropped
198 to zero. It must update next_out and avail_out when avail_out has dropped
199 to zero. The application must initialize zalloc, zfree and opaque before
200 calling the init function. All other fields are set by the compression
201 library and must not be updated by the application.
202
203 The opaque value provided by the application will be passed as the first
204 parameter for calls of zalloc and zfree. This can be useful for custom
205 memory management. The compression library attaches no meaning to the
206 opaque value.
207
208 zalloc must return Z_NULL if there is not enough memory for the object.
209 If zlib is used in a multi-threaded application, zalloc and zfree must be
210 thread safe.
211
212 On 16-bit systems, the functions zalloc and zfree must be able to allocate
213 exactly 65536 bytes, but will not be required to allocate more than this if
214 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
215 returned by zalloc for objects of exactly 65536 bytes *must* have their
216 offset normalized to zero. The default allocation function provided by this
217 library ensures this (see zutil.c). To reduce memory requirements and avoid
218 any allocation of 64K objects, at the expense of compression ratio, compile
219 the library with -DMAX_WBITS=14 (see zconf.h).
220
221 The fields total_in and total_out can be used for statistics or progress
222 reports. After compression, total_in holds the total size of the
223 uncompressed data and may be saved for use in the decompressor (particularly
224 if the decompressor wants to decompress everything in a single step).
225 */
226
227 /* constants */
228
229 #define Z_NO_FLUSH 0
230 #define Z_PARTIAL_FLUSH 1
231 #define Z_SYNC_FLUSH 2
232 #define Z_FULL_FLUSH 3
233 #define Z_FINISH 4
234 #define Z_BLOCK 5
235 #define Z_TREES 6
236 /* Allowed flush values; see deflate() and inflate() below for details */
237
238 #define Z_OK 0
239 #define Z_STREAM_END 1
240 #define Z_NEED_DICT 2
241 #define Z_ERRNO (-1)
242 #define Z_STREAM_ERROR (-2)
243 #define Z_DATA_ERROR (-3)
244 #define Z_MEM_ERROR (-4)
245 #define Z_BUF_ERROR (-5)
246 #define Z_VERSION_ERROR (-6)
247 /* Return codes for the compression/decompression functions. Negative values
248 * are errors, positive values are used for special but normal events.
249 */
250
251 #define Z_NO_COMPRESSION 0
252 #define Z_BEST_SPEED 1
253 #define Z_BEST_COMPRESSION 9
254 #define Z_DEFAULT_COMPRESSION (-1)
255 /* compression levels */
256
257 #define Z_FILTERED 1
258 #define Z_HUFFMAN_ONLY 2
259 #define Z_RLE 3
260 #define Z_FIXED 4
261 #define Z_DEFAULT_STRATEGY 0
262 /* compression strategy; see deflateInit2() below for details */
263
264 #define Z_BINARY 0
265 #define Z_TEXT 1
266 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
267 #define Z_UNKNOWN 2
268 /* Possible values of the data_type field (though see inflate()) */
269
270 #define Z_DEFLATED 8
271 /* The deflate compression method (the only one supported in this version) */
272
273 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
274
275 #define zlib_version zlibVersion()
276 /* for compatibility with versions < 1.0.2 */
277
278
279 /* basic functions */
280
281 ZEXTERN const char * ZEXPORT zlibVersion OF((void));
282 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
283 If the first character differs, the library code actually used is not
284 compatible with the zlib.h header file used by the application. This check
285 is automatically made by deflateInit and inflateInit.
286 */
287
288 /*
289 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
290
291 Initializes the internal stream state for compression. The fields
292 zalloc, zfree and opaque must be initialized before by the caller. If
293 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
294 allocation functions.
295
296 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
297 1 gives best speed, 9 gives best compression, 0 gives no compression at all
298 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
299 requests a default compromise between speed and compression (currently
300 equivalent to level 6).
301
302 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
303 memory, Z_STREAM_ERROR if level is not a valid compression level, or
304 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
305 with the version assumed by the caller (ZLIB_VERSION). msg is set to null
306 if there is no error message. deflateInit does not perform any compression:
307 this will be done by deflate().
308 */
309
310
311 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
312 /*
313 deflate compresses as much data as possible, and stops when the input
314 buffer becomes empty or the output buffer becomes full. It may introduce
315 some output latency (reading input without producing any output) except when
316 forced to flush.
317
318 The detailed semantics are as follows. deflate performs one or both of the
319 following actions:
320
321 - Compress more input starting at next_in and update next_in and avail_in
322 accordingly. If not all input can be processed (because there is not
323 enough room in the output buffer), next_in and avail_in are updated and
324 processing will resume at this point for the next call of deflate().
325
326 - Provide more output starting at next_out and update next_out and avail_out
327 accordingly. This action is forced if the parameter flush is non zero.
328 Forcing flush frequently degrades the compression ratio, so this parameter
329 should be set only when necessary (in interactive applications). Some
330 output may be provided even if flush is not set.
331
332 Before the call of deflate(), the application should ensure that at least
333 one of the actions is possible, by providing more input and/or consuming more
334 output, and updating avail_in or avail_out accordingly; avail_out should
335 never be zero before the call. The application can consume the compressed
336 output when it wants, for example when the output buffer is full (avail_out
337 == 0), or after each call of deflate(). If deflate returns Z_OK and with
338 zero avail_out, it must be called again after making room in the output
339 buffer because there might be more output pending.
340
341 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
342 decide how much data to accumulate before producing output, in order to
343 maximize compression.
344
345 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
346 flushed to the output buffer and the output is aligned on a byte boundary, so
347 that the decompressor can get all input data available so far. (In
348 particular avail_in is zero after the call if enough output space has been
349 provided before the call.) Flushing may degrade compression for some
350 compression algorithms and so it should be used only when necessary. This
351 completes the current deflate block and follows it with an empty stored block
352 that is three bits plus filler bits to the next byte, followed by four bytes
353 (00 00 ff ff).
354
355 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
356 output buffer, but the output is not aligned to a byte boundary. All of the
357 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
358 This completes the current deflate block and follows it with an empty fixed
359 codes block that is 10 bits long. This assures that enough bytes are output
360 in order for the decompressor to finish the block before the empty fixed code
361 block.
362
363 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
364 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
365 seven bits of the current block are held to be written as the next byte after
366 the next deflate block is completed. In this case, the decompressor may not
367 be provided enough bits at this point in order to complete decompression of
368 the data provided so far to the compressor. It may need to wait for the next
369 block to be emitted. This is for advanced applications that need to control
370 the emission of deflate blocks.
371
372 If flush is set to Z_FULL_FLUSH, all output is flushed as with
373 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
374 restart from this point if previous compressed data has been damaged or if
375 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
376 compression.
377
378 If deflate returns with avail_out == 0, this function must be called again
379 with the same value of the flush parameter and more output space (updated
380 avail_out), until the flush is complete (deflate returns with non-zero
381 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
382 avail_out is greater than six to avoid repeated flush markers due to
383 avail_out == 0 on return.
384
385 If the parameter flush is set to Z_FINISH, pending input is processed,
386 pending output is flushed and deflate returns with Z_STREAM_END if there was
387 enough output space; if deflate returns with Z_OK, this function must be
388 called again with Z_FINISH and more output space (updated avail_out) but no
389 more input data, until it returns with Z_STREAM_END or an error. After
390 deflate has returned Z_STREAM_END, the only possible operations on the stream
391 are deflateReset or deflateEnd.
392
393 Z_FINISH can be used immediately after deflateInit if all the compression
394 is to be done in a single step. In this case, avail_out must be at least the
395 value returned by deflateBound (see below). Then deflate is guaranteed to
396 return Z_STREAM_END. If not enough output space is provided, deflate will
397 not return Z_STREAM_END, and it must be called again as described above.
398
399 deflate() sets strm->adler to the adler32 checksum of all input read
400 so far (that is, total_in bytes).
401
402 deflate() may update strm->data_type if it can make a good guess about
403 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
404 binary. This field is only for information purposes and does not affect the
405 compression algorithm in any manner.
406
407 deflate() returns Z_OK if some progress has been made (more input
408 processed or more output produced), Z_STREAM_END if all input has been
409 consumed and all output has been produced (only when flush is set to
410 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
411 if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
412 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
413 fatal, and deflate() can be called again with more input and more output
414 space to continue compressing.
415 */
416
417
418 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
419 /*
420 All dynamically allocated data structures for this stream are freed.
421 This function discards any unprocessed input and does not flush any pending
422 output.
423
424 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
425 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
426 prematurely (some input or output was discarded). In the error case, msg
427 may be set but then points to a static string (which must not be
428 deallocated).
429 */
430
431
432 /*
433 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
434
435 Initializes the internal stream state for decompression. The fields
436 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
437 the caller. If next_in is not Z_NULL and avail_in is large enough (the
438 exact value depends on the compression method), inflateInit determines the
439 compression method from the zlib header and allocates all data structures
440 accordingly; otherwise the allocation will be deferred to the first call of
441 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
442 use default allocation functions.
443
444 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
445 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
446 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
447 invalid, such as a null pointer to the structure. msg is set to null if
448 there is no error message. inflateInit does not perform any decompression
449 apart from possibly reading the zlib header if present: actual decompression
450 will be done by inflate(). (So next_in and avail_in may be modified, but
451 next_out and avail_out are unused and unchanged.) The current implementation
452 of inflateInit() does not process any header information -- that is deferred
453 until inflate() is called.
454 */
455
456
457 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
458 /*
459 inflate decompresses as much data as possible, and stops when the input
460 buffer becomes empty or the output buffer becomes full. It may introduce
461 some output latency (reading input without producing any output) except when
462 forced to flush.
463
464 The detailed semantics are as follows. inflate performs one or both of the
465 following actions:
466
467 - Decompress more input starting at next_in and update next_in and avail_in
468 accordingly. If not all input can be processed (because there is not
469 enough room in the output buffer), next_in is updated and processing will
470 resume at this point for the next call of inflate().
471
472 - Provide more output starting at next_out and update next_out and avail_out
473 accordingly. inflate() provides as much output as possible, until there is
474 no more input data or no more space in the output buffer (see below about
475 the flush parameter).
476
477 Before the call of inflate(), the application should ensure that at least
478 one of the actions is possible, by providing more input and/or consuming more
479 output, and updating the next_* and avail_* values accordingly. The
480 application can consume the uncompressed output when it wants, for example
481 when the output buffer is full (avail_out == 0), or after each call of
482 inflate(). If inflate returns Z_OK and with zero avail_out, it must be
483 called again after making room in the output buffer because there might be
484 more output pending.
485
486 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
487 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
488 output as possible to the output buffer. Z_BLOCK requests that inflate()
489 stop if and when it gets to the next deflate block boundary. When decoding
490 the zlib or gzip format, this will cause inflate() to return immediately
491 after the header and before the first block. When doing a raw inflate,
492 inflate() will go ahead and process the first block, and will return when it
493 gets to the end of that block, or when it runs out of data.
494
495 The Z_BLOCK option assists in appending to or combining deflate streams.
496 Also to assist in this, on return inflate() will set strm->data_type to the
497 number of unused bits in the last byte taken from strm->next_in, plus 64 if
498 inflate() is currently decoding the last block in the deflate stream, plus
499 128 if inflate() returned immediately after decoding an end-of-block code or
500 decoding the complete header up to just before the first byte of the deflate
501 stream. The end-of-block will not be indicated until all of the uncompressed
502 data from that block has been written to strm->next_out. The number of
503 unused bits may in general be greater than seven, except when bit 7 of
504 data_type is set, in which case the number of unused bits will be less than
505 eight. data_type is set as noted here every time inflate() returns for all
506 flush options, and so can be used to determine the amount of currently
507 consumed input in bits.
508
509 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
510 end of each deflate block header is reached, before any actual data in that
511 block is decoded. This allows the caller to determine the length of the
512 deflate block header for later use in random access within a deflate block.
513 256 is added to the value of strm->data_type when inflate() returns
514 immediately after reaching the end of the deflate block header.
515
516 inflate() should normally be called until it returns Z_STREAM_END or an
517 error. However if all decompression is to be performed in a single step (a
518 single call of inflate), the parameter flush should be set to Z_FINISH. In
519 this case all pending input is processed and all pending output is flushed;
520 avail_out must be large enough to hold all of the uncompressed data for the
521 operation to complete. (The size of the uncompressed data may have been
522 saved by the compressor for this purpose.) The use of Z_FINISH is not
523 required to perform an inflation in one step. However it may be used to
524 inform inflate that a faster approach can be used for the single inflate()
525 call. Z_FINISH also informs inflate to not maintain a sliding window if the
526 stream completes, which reduces inflate's memory footprint. If the stream
527 does not complete, either because not all of the stream is provided or not
528 enough output space is provided, then a sliding window will be allocated and
529 inflate() can be called again to continue the operation as if Z_NO_FLUSH had
530 been used.
531
532 In this implementation, inflate() always flushes as much output as
533 possible to the output buffer, and always uses the faster approach on the
534 first call. So the effects of the flush parameter in this implementation are
535 on the return value of inflate() as noted below, when inflate() returns early
536 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
537 memory for a sliding window when Z_FINISH is used.
538
539 If a preset dictionary is needed after this call (see inflateSetDictionary
540 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
541 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
542 strm->adler to the Adler-32 checksum of all output produced so far (that is,
543 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
544 below. At the end of the stream, inflate() checks that its computed adler32
545 checksum is equal to that saved by the compressor and returns Z_STREAM_END
546 only if the checksum is correct.
547
548 inflate() can decompress and check either zlib-wrapped or gzip-wrapped
549 deflate data. The header type is detected automatically, if requested when
550 initializing with inflateInit2(). Any information contained in the gzip
551 header is not retained, so applications that need that information should
552 instead use raw inflate, see inflateInit2() below, or inflateBack() and
553 perform their own processing of the gzip header and trailer. When processing
554 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
555 producted so far. The CRC-32 is checked against the gzip trailer.
556
557 inflate() returns Z_OK if some progress has been made (more input processed
558 or more output produced), Z_STREAM_END if the end of the compressed data has
559 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
560 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
561 corrupted (input stream not conforming to the zlib format or incorrect check
562 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
563 next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
564 Z_BUF_ERROR if no progress is possible or if there was not enough room in the
565 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
566 inflate() can be called again with more input and more output space to
567 continue decompressing. If Z_DATA_ERROR is returned, the application may
568 then call inflateSync() to look for a good compression block if a partial
569 recovery of the data is desired.
570 */
571
572
573 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
574 /*
575 All dynamically allocated data structures for this stream are freed.
576 This function discards any unprocessed input and does not flush any pending
577 output.
578
579 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
580 was inconsistent. In the error case, msg may be set but then points to a
581 static string (which must not be deallocated).
582 */
583
584
585 /* Advanced functions */
586
587 /*
588 The following functions are needed only in some special applications.
589 */
590
591 /*
592 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
593 int level,
594 int method,
595 int windowBits,
596 int memLevel,
597 int strategy));
598
599 This is another version of deflateInit with more compression options. The
600 fields next_in, zalloc, zfree and opaque must be initialized before by the
601 caller.
602
603 The method parameter is the compression method. It must be Z_DEFLATED in
604 this version of the library.
605
606 The windowBits parameter is the base two logarithm of the window size
607 (the size of the history buffer). It should be in the range 8..15 for this
608 version of the library. Larger values of this parameter result in better
609 compression at the expense of memory usage. The default value is 15 if
610 deflateInit is used instead.
611
612 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
613 determines the window size. deflate() will then generate raw deflate data
614 with no zlib header or trailer, and will not compute an adler32 check value.
615
616 windowBits can also be greater than 15 for optional gzip encoding. Add
617 16 to windowBits to write a simple gzip header and trailer around the
618 compressed data instead of a zlib wrapper. The gzip header will have no
619 file name, no extra data, no comment, no modification time (set to zero), no
620 header crc, and the operating system will be set to 255 (unknown). If a
621 gzip stream is being written, strm->adler is a crc32 instead of an adler32.
622
623 The memLevel parameter specifies how much memory should be allocated
624 for the internal compression state. memLevel=1 uses minimum memory but is
625 slow and reduces compression ratio; memLevel=9 uses maximum memory for
626 optimal speed. The default value is 8. See zconf.h for total memory usage
627 as a function of windowBits and memLevel.
628
629 The strategy parameter is used to tune the compression algorithm. Use the
630 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
631 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
632 string match), or Z_RLE to limit match distances to one (run-length
633 encoding). Filtered data consists mostly of small values with a somewhat
634 random distribution. In this case, the compression algorithm is tuned to
635 compress them better. The effect of Z_FILTERED is to force more Huffman
636 coding and less string matching; it is somewhat intermediate between
637 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
638 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
639 strategy parameter only affects the compression ratio but not the
640 correctness of the compressed output even if it is not set appropriately.
641 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
642 decoder for special applications.
643
644 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
645 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
646 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
647 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
648 set to null if there is no error message. deflateInit2 does not perform any
649 compression: this will be done by deflate().
650 */
651
652 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
653 const Bytef *dictionary,
654 uInt dictLength));
655 /*
656 Initializes the compression dictionary from the given byte sequence
657 without producing any compressed output. When using the zlib format, this
658 function must be called immediately after deflateInit, deflateInit2 or
659 deflateReset, and before any call of deflate. When doing raw deflate, this
660 function must be called either before any call of deflate, or immediately
661 after the completion of a deflate block, i.e. after all input has been
662 consumed and all output has been delivered when using any of the flush
663 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The
664 compressor and decompressor must use exactly the same dictionary (see
665 inflateSetDictionary).
666
667 The dictionary should consist of strings (byte sequences) that are likely
668 to be encountered later in the data to be compressed, with the most commonly
669 used strings preferably put towards the end of the dictionary. Using a
670 dictionary is most useful when the data to be compressed is short and can be
671 predicted with good accuracy; the data can then be compressed better than
672 with the default empty dictionary.
673
674 Depending on the size of the compression data structures selected by
675 deflateInit or deflateInit2, a part of the dictionary may in effect be
676 discarded, for example if the dictionary is larger than the window size
677 provided in deflateInit or deflateInit2. Thus the strings most likely to be
678 useful should be put at the end of the dictionary, not at the front. In
679 addition, the current implementation of deflate will use at most the window
680 size minus 262 bytes of the provided dictionary.
681
682 Upon return of this function, strm->adler is set to the adler32 value
683 of the dictionary; the decompressor may later use this value to determine
684 which dictionary has been used by the compressor. (The adler32 value
685 applies to the whole dictionary even if only a subset of the dictionary is
686 actually used by the compressor.) If a raw deflate was requested, then the
687 adler32 value is not computed and strm->adler is not set.
688
689 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
690 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
691 inconsistent (for example if deflate has already been called for this stream
692 or if not at a block boundary for raw deflate). deflateSetDictionary does
693 not perform any compression: this will be done by deflate().
694 */
695
696 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
697 z_streamp source));
698 /*
699 Sets the destination stream as a complete copy of the source stream.
700
701 This function can be useful when several compression strategies will be
702 tried, for example when there are several ways of pre-processing the input
703 data with a filter. The streams that will be discarded should then be freed
704 by calling deflateEnd. Note that deflateCopy duplicates the internal
705 compression state which can be quite large, so this strategy is slow and can
706 consume lots of memory.
707
708 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
709 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
710 (such as zalloc being Z_NULL). msg is left unchanged in both source and
711 destination.
712 */
713
714 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
715 /*
716 This function is equivalent to deflateEnd followed by deflateInit,
717 but does not free and reallocate all the internal compression state. The
718 stream will keep the same compression level and any other attributes that
719 may have been set by deflateInit2.
720
721 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
722 stream state was inconsistent (such as zalloc or state being Z_NULL).
723 */
724
725 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
726 int level,
727 int strategy));
728 /*
729 Dynamically update the compression level and compression strategy. The
730 interpretation of level and strategy is as in deflateInit2. This can be
731 used to switch between compression and straight copy of the input data, or
732 to switch to a different kind of input data requiring a different strategy.
733 If the compression level is changed, the input available so far is
734 compressed with the old level (and may be flushed); the new level will take
735 effect only at the next call of deflate().
736
737 Before the call of deflateParams, the stream state must be set as for
738 a call of deflate(), since the currently available input may have to be
739 compressed and flushed. In particular, strm->avail_out must be non-zero.
740
741 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
742 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
743 strm->avail_out was zero.
744 */
745
746 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
747 int good_length,
748 int max_lazy,
749 int nice_length,
750 int max_chain));
751 /*
752 Fine tune deflate's internal compression parameters. This should only be
753 used by someone who understands the algorithm used by zlib's deflate for
754 searching for the best matching string, and even then only by the most
755 fanatic optimizer trying to squeeze out the last compressed bit for their
756 specific input data. Read the deflate.c source code for the meaning of the
757 max_lazy, good_length, nice_length, and max_chain parameters.
758
759 deflateTune() can be called after deflateInit() or deflateInit2(), and
760 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
761 */
762
763 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
764 uLong sourceLen));
765 /*
766 deflateBound() returns an upper bound on the compressed size after
767 deflation of sourceLen bytes. It must be called after deflateInit() or
768 deflateInit2(), and after deflateSetHeader(), if used. This would be used
769 to allocate an output buffer for deflation in a single pass, and so would be
770 called before deflate(). If that first deflate() call is provided the
771 sourceLen input bytes, an output buffer allocated to the size returned by
772 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
773 to return Z_STREAM_END. Note that it is possible for the compressed size to
774 be larger than the value returned by deflateBound() if flush options other
775 than Z_FINISH or Z_NO_FLUSH are used.
776 */
777
778 ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
779 unsigned *pending,
780 int *bits));
781 /*
782 deflatePending() returns the number of bytes and bits of output that have
783 been generated, but not yet provided in the available output. The bytes not
784 provided would be due to the available output space having being consumed.
785 The number of bits of output not provided are between 0 and 7, where they
786 await more bits to join them in order to fill out a full byte. If pending
787 or bits are Z_NULL, then those values are not set.
788
789 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
790 stream state was inconsistent.
791 */
792
793 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
794 int bits,
795 int value));
796 /*
797 deflatePrime() inserts bits in the deflate output stream. The intent
798 is that this function is used to start off the deflate output with the bits
799 leftover from a previous deflate stream when appending to it. As such, this
800 function can only be used for raw deflate, and must be used before the first
801 deflate() call after a deflateInit2() or deflateReset(). bits must be less
802 than or equal to 16, and that many of the least significant bits of value
803 will be inserted in the output.
804
805 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
806 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
807 source stream state was inconsistent.
808 */
809
810 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
811 gz_headerp head));
812 /*
813 deflateSetHeader() provides gzip header information for when a gzip
814 stream is requested by deflateInit2(). deflateSetHeader() may be called
815 after deflateInit2() or deflateReset() and before the first call of
816 deflate(). The text, time, os, extra field, name, and comment information
817 in the provided gz_header structure are written to the gzip header (xflag is
818 ignored -- the extra flags are set according to the compression level). The
819 caller must assure that, if not Z_NULL, name and comment are terminated with
820 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
821 available there. If hcrc is true, a gzip header crc is included. Note that
822 the current versions of the command-line version of gzip (up through version
823 1.3.x) do not support header crc's, and will report that it is a "multi-part
824 gzip file" and give up.
825
826 If deflateSetHeader is not used, the default gzip header has text false,
827 the time set to zero, and os set to 255, with no extra, name, or comment
828 fields. The gzip header is returned to the default state by deflateReset().
829
830 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
831 stream state was inconsistent.
832 */
833
834 /*
835 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
836 int windowBits));
837
838 This is another version of inflateInit with an extra parameter. The
839 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
840 before by the caller.
841
842 The windowBits parameter is the base two logarithm of the maximum window
843 size (the size of the history buffer). It should be in the range 8..15 for
844 this version of the library. The default value is 15 if inflateInit is used
845 instead. windowBits must be greater than or equal to the windowBits value
846 provided to deflateInit2() while compressing, or it must be equal to 15 if
847 deflateInit2() was not used. If a compressed stream with a larger window
848 size is given as input, inflate() will return with the error code
849 Z_DATA_ERROR instead of trying to allocate a larger window.
850
851 windowBits can also be zero to request that inflate use the window size in
852 the zlib header of the compressed stream.
853
854 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
855 determines the window size. inflate() will then process raw deflate data,
856 not looking for a zlib or gzip header, not generating a check value, and not
857 looking for any check values for comparison at the end of the stream. This
858 is for use with other formats that use the deflate compressed data format
859 such as zip. Those formats provide their own check values. If a custom
860 format is developed using the raw deflate format for compressed data, it is
861 recommended that a check value such as an adler32 or a crc32 be applied to
862 the uncompressed data as is done in the zlib, gzip, and zip formats. For
863 most applications, the zlib format should be used as is. Note that comments
864 above on the use in deflateInit2() applies to the magnitude of windowBits.
865
866 windowBits can also be greater than 15 for optional gzip decoding. Add
867 32 to windowBits to enable zlib and gzip decoding with automatic header
868 detection, or add 16 to decode only the gzip format (the zlib format will
869 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
870 crc32 instead of an adler32.
871
872 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
873 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
874 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
875 invalid, such as a null pointer to the structure. msg is set to null if
876 there is no error message. inflateInit2 does not perform any decompression
877 apart from possibly reading the zlib header if present: actual decompression
878 will be done by inflate(). (So next_in and avail_in may be modified, but
879 next_out and avail_out are unused and unchanged.) The current implementation
880 of inflateInit2() does not process any header information -- that is
881 deferred until inflate() is called.
882 */
883
884 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
885 const Bytef *dictionary,
886 uInt dictLength));
887 /*
888 Initializes the decompression dictionary from the given uncompressed byte
889 sequence. This function must be called immediately after a call of inflate,
890 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
891 can be determined from the adler32 value returned by that call of inflate.
892 The compressor and decompressor must use exactly the same dictionary (see
893 deflateSetDictionary). For raw inflate, this function can be called at any
894 time to set the dictionary. If the provided dictionary is smaller than the
895 window and there is already data in the window, then the provided dictionary
896 will amend what's there. The application must insure that the dictionary
897 that was used for compression is provided.
898
899 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
900 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
901 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
902 expected one (incorrect adler32 value). inflateSetDictionary does not
903 perform any decompression: this will be done by subsequent calls of
904 inflate().
905 */
906
907 ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
908 Bytef *dictionary,
909 uInt *dictLength));
910 /*
911 Returns the sliding dictionary being maintained by inflate. dictLength is
912 set to the number of bytes in the dictionary, and that many bytes are copied
913 to dictionary. dictionary must have enough space, where 32768 bytes is
914 always enough. If inflateGetDictionary() is called with dictionary equal to
915 Z_NULL, then only the dictionary length is returned, and nothing is copied.
916 Similary, if dictLength is Z_NULL, then it is not set.
917
918 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
919 stream state is inconsistent.
920 */
921
922 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
923 /*
924 Skips invalid compressed data until a possible full flush point (see above
925 for the description of deflate with Z_FULL_FLUSH) can be found, or until all
926 available input is skipped. No output is provided.
927
928 inflateSync searches for a 00 00 FF FF pattern in the compressed data.
929 All full flush points have this pattern, but not all occurrences of this
930 pattern are full flush points.
931
932 inflateSync returns Z_OK if a possible full flush point has been found,
933 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
934 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
935 In the success case, the application may save the current current value of
936 total_in which indicates where valid compressed data was found. In the
937 error case, the application may repeatedly call inflateSync, providing more
938 input each time, until success or end of the input data.
939 */
940
941 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
942 z_streamp source));
943 /*
944 Sets the destination stream as a complete copy of the source stream.
945
946 This function can be useful when randomly accessing a large stream. The
947 first pass through the stream can periodically record the inflate state,
948 allowing restarting inflate at those points when randomly accessing the
949 stream.
950
951 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
952 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
953 (such as zalloc being Z_NULL). msg is left unchanged in both source and
954 destination.
955 */
956
957 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
958 /*
959 This function is equivalent to inflateEnd followed by inflateInit,
960 but does not free and reallocate all the internal decompression state. The
961 stream will keep attributes that may have been set by inflateInit2.
962
963 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
964 stream state was inconsistent (such as zalloc or state being Z_NULL).
965 */
966
967 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
968 int windowBits));
969 /*
970 This function is the same as inflateReset, but it also permits changing
971 the wrap and window size requests. The windowBits parameter is interpreted
972 the same as it is for inflateInit2.
973
974 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
975 stream state was inconsistent (such as zalloc or state being Z_NULL), or if
976 the windowBits parameter is invalid.
977 */
978
979 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
980 int bits,
981 int value));
982 /*
983 This function inserts bits in the inflate input stream. The intent is
984 that this function is used to start inflating at a bit position in the
985 middle of a byte. The provided bits will be used before any bytes are used
986 from next_in. This function should only be used with raw inflate, and
987 should be used before the first inflate() call after inflateInit2() or
988 inflateReset(). bits must be less than or equal to 16, and that many of the
989 least significant bits of value will be inserted in the input.
990
991 If bits is negative, then the input stream bit buffer is emptied. Then
992 inflatePrime() can be called again to put bits in the buffer. This is used
993 to clear out bits leftover after feeding inflate a block description prior
994 to feeding inflate codes.
995
996 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
997 stream state was inconsistent.
998 */
999
1000 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
1001 /*
1002 This function returns two values, one in the lower 16 bits of the return
1003 value, and the other in the remaining upper bits, obtained by shifting the
1004 return value down 16 bits. If the upper value is -1 and the lower value is
1005 zero, then inflate() is currently decoding information outside of a block.
1006 If the upper value is -1 and the lower value is non-zero, then inflate is in
1007 the middle of a stored block, with the lower value equaling the number of
1008 bytes from the input remaining to copy. If the upper value is not -1, then
1009 it is the number of bits back from the current bit position in the input of
1010 the code (literal or length/distance pair) currently being processed. In
1011 that case the lower value is the number of bytes already emitted for that
1012 code.
1013
1014 A code is being processed if inflate is waiting for more input to complete
1015 decoding of the code, or if it has completed decoding but is waiting for
1016 more output space to write the literal or match data.
1017
1018 inflateMark() is used to mark locations in the input data for random
1019 access, which may be at bit positions, and to note those cases where the
1020 output of a code may span boundaries of random access blocks. The current
1021 location in the input stream can be determined from avail_in and data_type
1022 as noted in the description for the Z_BLOCK flush parameter for inflate.
1023
1024 inflateMark returns the value noted above or -1 << 16 if the provided
1025 source stream state was inconsistent.
1026 */
1027
1028 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
1029 gz_headerp head));
1030 /*
1031 inflateGetHeader() requests that gzip header information be stored in the
1032 provided gz_header structure. inflateGetHeader() may be called after
1033 inflateInit2() or inflateReset(), and before the first call of inflate().
1034 As inflate() processes the gzip stream, head->done is zero until the header
1035 is completed, at which time head->done is set to one. If a zlib stream is
1036 being decoded, then head->done is set to -1 to indicate that there will be
1037 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
1038 used to force inflate() to return immediately after header processing is
1039 complete and before any actual data is decompressed.
1040
1041 The text, time, xflags, and os fields are filled in with the gzip header
1042 contents. hcrc is set to true if there is a header CRC. (The header CRC
1043 was valid if done is set to one.) If extra is not Z_NULL, then extra_max
1044 contains the maximum number of bytes to write to extra. Once done is true,
1045 extra_len contains the actual extra field length, and extra contains the
1046 extra field, or that field truncated if extra_max is less than extra_len.
1047 If name is not Z_NULL, then up to name_max characters are written there,
1048 terminated with a zero unless the length is greater than name_max. If
1049 comment is not Z_NULL, then up to comm_max characters are written there,
1050 terminated with a zero unless the length is greater than comm_max. When any
1051 of extra, name, or comment are not Z_NULL and the respective field is not
1052 present in the header, then that field is set to Z_NULL to signal its
1053 absence. This allows the use of deflateSetHeader() with the returned
1054 structure to duplicate the header. However if those fields are set to
1055 allocated memory, then the application will need to save those pointers
1056 elsewhere so that they can be eventually freed.
1057
1058 If inflateGetHeader is not used, then the header information is simply
1059 discarded. The header is always checked for validity, including the header
1060 CRC if present. inflateReset() will reset the process to discard the header
1061 information. The application would need to call inflateGetHeader() again to
1062 retrieve the header from the next gzip stream.
1063
1064 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
1065 stream state was inconsistent.
1066 */
1067
1068 /*
1069 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
1070 unsigned char FAR *window));
1071
1072 Initialize the internal stream state for decompression using inflateBack()
1073 calls. The fields zalloc, zfree and opaque in strm must be initialized
1074 before the call. If zalloc and zfree are Z_NULL, then the default library-
1075 derived memory allocation routines are used. windowBits is the base two
1076 logarithm of the window size, in the range 8..15. window is a caller
1077 supplied buffer of that size. Except for special applications where it is
1078 assured that deflate was used with small window sizes, windowBits must be 15
1079 and a 32K byte window must be supplied to be able to decompress general
1080 deflate streams.
1081
1082 See inflateBack() for the usage of these routines.
1083
1084 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
1085 the parameters are invalid, Z_MEM_ERROR if the internal state could not be
1086 allocated, or Z_VERSION_ERROR if the version of the library does not match
1087 the version of the header file.
1088 */
1089
1090 typedef unsigned (*in_func) OF((void FAR *,
1091 z_const unsigned char FAR * FAR *));
1092 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
1093
1094 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
1095 in_func in, void FAR *in_desc,
1096 out_func out, void FAR *out_desc));
1097 /*
1098 inflateBack() does a raw inflate with a single call using a call-back
1099 interface for input and output. This is potentially more efficient than
1100 inflate() for file i/o applications, in that it avoids copying between the
1101 output and the sliding window by simply making the window itself the output
1102 buffer. inflate() can be faster on modern CPUs when used with large
1103 buffers. inflateBack() trusts the application to not change the output
1104 buffer passed by the output function, at least until inflateBack() returns.
1105
1106 inflateBackInit() must be called first to allocate the internal state
1107 and to initialize the state with the user-provided window buffer.
1108 inflateBack() may then be used multiple times to inflate a complete, raw
1109 deflate stream with each call. inflateBackEnd() is then called to free the
1110 allocated state.
1111
1112 A raw deflate stream is one with no zlib or gzip header or trailer.
1113 This routine would normally be used in a utility that reads zip or gzip
1114 files and writes out uncompressed files. The utility would decode the
1115 header and process the trailer on its own, hence this routine expects only
1116 the raw deflate stream to decompress. This is different from the normal
1117 behavior of inflate(), which expects either a zlib or gzip header and
1118 trailer around the deflate stream.
1119
1120 inflateBack() uses two subroutines supplied by the caller that are then
1121 called by inflateBack() for input and output. inflateBack() calls those
1122 routines until it reads a complete deflate stream and writes out all of the
1123 uncompressed data, or until it encounters an error. The function's
1124 parameters and return types are defined above in the in_func and out_func
1125 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
1126 number of bytes of provided input, and a pointer to that input in buf. If
1127 there is no input available, in() must return zero--buf is ignored in that
1128 case--and inflateBack() will return a buffer error. inflateBack() will call
1129 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
1130 should return zero on success, or non-zero on failure. If out() returns
1131 non-zero, inflateBack() will return with an error. Neither in() nor out()
1132 are permitted to change the contents of the window provided to
1133 inflateBackInit(), which is also the buffer that out() uses to write from.
1134 The length written by out() will be at most the window size. Any non-zero
1135 amount of input may be provided by in().
1136
1137 For convenience, inflateBack() can be provided input on the first call by
1138 setting strm->next_in and strm->avail_in. If that input is exhausted, then
1139 in() will be called. Therefore strm->next_in must be initialized before
1140 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
1141 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
1142 must also be initialized, and then if strm->avail_in is not zero, input will
1143 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
1144
1145 The in_desc and out_desc parameters of inflateBack() is passed as the
1146 first parameter of in() and out() respectively when they are called. These
1147 descriptors can be optionally used to pass any information that the caller-
1148 supplied in() and out() functions need to do their job.
1149
1150 On return, inflateBack() will set strm->next_in and strm->avail_in to
1151 pass back any unused input that was provided by the last in() call. The
1152 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
1153 if in() or out() returned an error, Z_DATA_ERROR if there was a format error
1154 in the deflate stream (in which case strm->msg is set to indicate the nature
1155 of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
1156 In the case of Z_BUF_ERROR, an input or output error can be distinguished
1157 using strm->next_in which will be Z_NULL only if in() returned an error. If
1158 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1159 non-zero. (in() will always be called before out(), so strm->next_in is
1160 assured to be defined if out() returns non-zero.) Note that inflateBack()
1161 cannot return Z_OK.
1162 */
1163
1164 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
1165 /*
1166 All memory allocated by inflateBackInit() is freed.
1167
1168 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
1169 state was inconsistent.
1170 */
1171
1172 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
1173 /* Return flags indicating compile-time options.
1174
1175 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1176 1.0: size of uInt
1177 3.2: size of uLong
1178 5.4: size of voidpf (pointer)
1179 7.6: size of z_off_t
1180
1181 Compiler, assembler, and debug options:
1182 8: DEBUG
1183 9: ASMV or ASMINF -- use ASM code
1184 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1185 11: 0 (reserved)
1186
1187 One-time table building (smaller code, but not thread-safe if true):
1188 12: BUILDFIXED -- build static block decoding tables when needed
1189 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1190 14,15: 0 (reserved)
1191
1192 Library content (indicates missing functionality):
1193 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1194 deflate code when not needed)
1195 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1196 and decode gzip streams (to avoid linking crc code)
1197 18-19: 0 (reserved)
1198
1199 Operation variations (changes in library functionality):
1200 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1201 21: FASTEST -- deflate algorithm with only one, lowest compression level
1202 22,23: 0 (reserved)
1203
1204 The sprintf variant used by gzprintf (zero is best):
1205 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1206 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1207 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1208
1209 Remainder:
1210 27-31: 0 (reserved)
1211 */
1212
1213 #ifndef Z_SOLO
1214
1215 /* utility functions */
1216
1217 /*
1218 The following utility functions are implemented on top of the basic
1219 stream-oriented functions. To simplify the interface, some default options
1220 are assumed (compression level and memory usage, standard memory allocation
1221 functions). The source code of these utility functions can be modified if
1222 you need special options.
1223 */
1224
1225 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
1226 const Bytef *source, uLong sourceLen));
1227 /*
1228 Compresses the source buffer into the destination buffer. sourceLen is
1229 the byte length of the source buffer. Upon entry, destLen is the total size
1230 of the destination buffer, which must be at least the value returned by
1231 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1232 compressed buffer.
1233
1234 compress returns Z_OK if success, Z_MEM_ERROR if there was not
1235 enough memory, Z_BUF_ERROR if there was not enough room in the output
1236 buffer.
1237 */
1238
1239 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
1240 const Bytef *source, uLong sourceLen,
1241 int level));
1242 /*
1243 Compresses the source buffer into the destination buffer. The level
1244 parameter has the same meaning as in deflateInit. sourceLen is the byte
1245 length of the source buffer. Upon entry, destLen is the total size of the
1246 destination buffer, which must be at least the value returned by
1247 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1248 compressed buffer.
1249
1250 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1251 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1252 Z_STREAM_ERROR if the level parameter is invalid.
1253 */
1254
1255 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1256 /*
1257 compressBound() returns an upper bound on the compressed size after
1258 compress() or compress2() on sourceLen bytes. It would be used before a
1259 compress() or compress2() call to allocate the destination buffer.
1260 */
1261
1262 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
1263 const Bytef *source, uLong sourceLen));
1264 /*
1265 Decompresses the source buffer into the destination buffer. sourceLen is
1266 the byte length of the source buffer. Upon entry, destLen is the total size
1267 of the destination buffer, which must be large enough to hold the entire
1268 uncompressed data. (The size of the uncompressed data must have been saved
1269 previously by the compressor and transmitted to the decompressor by some
1270 mechanism outside the scope of this compression library.) Upon exit, destLen
1271 is the actual size of the uncompressed buffer.
1272
1273 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1274 enough memory, Z_BUF_ERROR if there was not enough room in the output
1275 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In
1276 the case where there is not enough room, uncompress() will fill the output
1277 buffer with the uncompressed data up to that point.
1278 */
1279
1280 /* gzip file access functions */
1281
1282 /*
1283 This library supports reading and writing files in gzip (.gz) format with
1284 an interface similar to that of stdio, using the functions that start with
1285 "gz". The gzip format is different from the zlib format. gzip is a gzip
1286 wrapper, documented in RFC 1952, wrapped around a deflate stream.
1287 */
1288
1289 typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
1290
1291 /*
1292 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1293
1294 Opens a gzip (.gz) file for reading or writing. The mode parameter is as
1295 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
1296 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
1297 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
1298 for fixed code compression as in "wb9F". (See the description of
1299 deflateInit2 for more information about the strategy parameter.) 'T' will
1300 request transparent writing or appending with no compression and not using
1301 the gzip format.
1302
1303 "a" can be used instead of "w" to request that the gzip stream that will
1304 be written be appended to the file. "+" will result in an error, since
1305 reading and writing to the same gzip file is not supported. The addition of
1306 "x" when writing will create the file exclusively, which fails if the file
1307 already exists. On systems that support it, the addition of "e" when
1308 reading or writing will set the flag to close the file on an execve() call.
1309
1310 These functions, as well as gzip, will read and decode a sequence of gzip
1311 streams in a file. The append function of gzopen() can be used to create
1312 such a file. (Also see gzflush() for another way to do this.) When
1313 appending, gzopen does not test whether the file begins with a gzip stream,
1314 nor does it look for the end of the gzip streams to begin appending. gzopen
1315 will simply append a gzip stream to the existing file.
1316
1317 gzopen can be used to read a file which is not in gzip format; in this
1318 case gzread will directly read from the file without decompression. When
1319 reading, this will be detected automatically by looking for the magic two-
1320 byte gzip header.
1321
1322 gzopen returns NULL if the file could not be opened, if there was
1323 insufficient memory to allocate the gzFile state, or if an invalid mode was
1324 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
1325 errno can be checked to determine if the reason gzopen failed was that the
1326 file could not be opened.
1327 */
1328
1329 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1330 /*
1331 gzdopen associates a gzFile with the file descriptor fd. File descriptors
1332 are obtained from calls like open, dup, creat, pipe or fileno (if the file
1333 has been previously opened with fopen). The mode parameter is as in gzopen.
1334
1335 The next call of gzclose on the returned gzFile will also close the file
1336 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
1337 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
1338 mode);. The duplicated descriptor should be saved to avoid a leak, since
1339 gzdopen does not close fd if it fails. If you are using fileno() to get the
1340 file descriptor from a FILE *, then you will have to use dup() to avoid
1341 double-close()ing the file descriptor. Both gzclose() and fclose() will
1342 close the associated file descriptor, so they need to have different file
1343 descriptors.
1344
1345 gzdopen returns NULL if there was insufficient memory to allocate the
1346 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
1347 provided, or '+' was provided), or if fd is -1. The file descriptor is not
1348 used until the next gz* read, write, seek, or close operation, so gzdopen
1349 will not detect if fd is invalid (unless fd is -1).
1350 */
1351
1352 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
1353 /*
1354 Set the internal buffer size used by this library's functions. The
1355 default buffer size is 8192 bytes. This function must be called after
1356 gzopen() or gzdopen(), and before any other calls that read or write the
1357 file. The buffer memory allocation is always deferred to the first read or
1358 write. Two buffers are allocated, either both of the specified size when
1359 writing, or one of the specified size and the other twice that size when
1360 reading. A larger buffer size of, for example, 64K or 128K bytes will
1361 noticeably increase the speed of decompression (reading).
1362
1363 The new buffer size also affects the maximum length for gzprintf().
1364
1365 gzbuffer() returns 0 on success, or -1 on failure, such as being called
1366 too late.
1367 */
1368
1369 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1370 /*
1371 Dynamically update the compression level or strategy. See the description
1372 of deflateInit2 for the meaning of these parameters.
1373
1374 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
1375 opened for writing.
1376 */
1377
1378 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1379 /*
1380 Reads the given number of uncompressed bytes from the compressed file. If
1381 the input file is not in gzip format, gzread copies the given number of
1382 bytes into the buffer directly from the file.
1383
1384 After reaching the end of a gzip stream in the input, gzread will continue
1385 to read, looking for another gzip stream. Any number of gzip streams may be
1386 concatenated in the input file, and will all be decompressed by gzread().
1387 If something other than a gzip stream is encountered after a gzip stream,
1388 that remaining trailing garbage is ignored (and no error is returned).
1389
1390 gzread can be used to read a gzip file that is being concurrently written.
1391 Upon reaching the end of the input, gzread will return with the available
1392 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
1393 gzclearerr can be used to clear the end of file indicator in order to permit
1394 gzread to be tried again. Z_OK indicates that a gzip stream was completed
1395 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the
1396 middle of a gzip stream. Note that gzread does not return -1 in the event
1397 of an incomplete gzip stream. This error is deferred until gzclose(), which
1398 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
1399 stream. Alternatively, gzerror can be used before gzclose to detect this
1400 case.
1401
1402 gzread returns the number of uncompressed bytes actually read, less than
1403 len for end of file, or -1 for error.
1404 */
1405
1406 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
1407 voidpc buf, unsigned len));
1408 /*
1409 Writes the given number of uncompressed bytes into the compressed file.
1410 gzwrite returns the number of uncompressed bytes written or 0 in case of
1411 error.
1412 */
1413
1414 ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
1415 /*
1416 Converts, formats, and writes the arguments to the compressed file under
1417 control of the format string, as in fprintf. gzprintf returns the number of
1418 uncompressed bytes actually written, or 0 in case of error. The number of
1419 uncompressed bytes written is limited to 8191, or one less than the buffer
1420 size given to gzbuffer(). The caller should assure that this limit is not
1421 exceeded. If it is exceeded, then gzprintf() will return an error (0) with
1422 nothing written. In this case, there may also be a buffer overflow with
1423 unpredictable consequences, which is possible only if zlib was compiled with
1424 the insecure functions sprintf() or vsprintf() because the secure snprintf()
1425 or vsnprintf() functions were not available. This can be determined using
1426 zlibCompileFlags().
1427 */
1428
1429 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1430 /*
1431 Writes the given null-terminated string to the compressed file, excluding
1432 the terminating null character.
1433
1434 gzputs returns the number of characters written, or -1 in case of error.
1435 */
1436
1437 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1438 /*
1439 Reads bytes from the compressed file until len-1 characters are read, or a
1440 newline character is read and transferred to buf, or an end-of-file
1441 condition is encountered. If any characters are read or if len == 1, the
1442 string is terminated with a null character. If no characters are read due
1443 to an end-of-file or len < 1, then the buffer is left untouched.
1444
1445 gzgets returns buf which is a null-terminated string, or it returns NULL
1446 for end-of-file or in case of error. If there was an error, the contents at
1447 buf are indeterminate.
1448 */
1449
1450 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1451 /*
1452 Writes c, converted to an unsigned char, into the compressed file. gzputc
1453 returns the value that was written, or -1 in case of error.
1454 */
1455
1456 ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1457 /*
1458 Reads one byte from the compressed file. gzgetc returns this byte or -1
1459 in case of end of file or error. This is implemented as a macro for speed.
1460 As such, it does not do all of the checking the other functions do. I.e.
1461 it does not check to see if file is NULL, nor whether the structure file
1462 points to has been clobbered or not.
1463 */
1464
1465 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1466 /*
1467 Push one character back onto the stream to be read as the first character
1468 on the next read. At least one character of push-back is allowed.
1469 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
1470 fail if c is -1, and may fail if a character has been pushed but not read
1471 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
1472 output buffer size of pushed characters is allowed. (See gzbuffer above.)
1473 The pushed character will be discarded if the stream is repositioned with
1474 gzseek() or gzrewind().
1475 */
1476
1477 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1478 /*
1479 Flushes all pending output into the compressed file. The parameter flush
1480 is as in the deflate() function. The return value is the zlib error number
1481 (see function gzerror below). gzflush is only permitted when writing.
1482
1483 If the flush parameter is Z_FINISH, the remaining data is written and the
1484 gzip stream is completed in the output. If gzwrite() is called again, a new
1485 gzip stream will be started in the output. gzread() is able to read such
1486 concatented gzip streams.
1487
1488 gzflush should be called only when strictly necessary because it will
1489 degrade compression if called too often.
1490 */
1491
1492 /*
1493 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1494 z_off_t offset, int whence));
1495
1496 Sets the starting position for the next gzread or gzwrite on the given
1497 compressed file. The offset represents a number of bytes in the
1498 uncompressed data stream. The whence parameter is defined as in lseek(2);
1499 the value SEEK_END is not supported.
1500
1501 If the file is opened for reading, this function is emulated but can be
1502 extremely slow. If the file is opened for writing, only forward seeks are
1503 supported; gzseek then compresses a sequence of zeroes up to the new
1504 starting position.
1505
1506 gzseek returns the resulting offset location as measured in bytes from
1507 the beginning of the uncompressed stream, or -1 in case of error, in
1508 particular if the file is opened for writing and the new starting position
1509 would be before the current position.
1510 */
1511
1512 ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
1513 /*
1514 Rewinds the given file. This function is supported only for reading.
1515
1516 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1517 */
1518
1519 /*
1520 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1521
1522 Returns the starting position for the next gzread or gzwrite on the given
1523 compressed file. This position represents a number of bytes in the
1524 uncompressed data stream, and is zero when starting, even if appending or
1525 reading a gzip stream from the middle of a file using gzdopen().
1526
1527 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1528 */
1529
1530 /*
1531 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
1532
1533 Returns the current offset in the file being read or written. This offset
1534 includes the count of bytes that precede the gzip stream, for example when
1535 appending or when using gzdopen() for reading. When reading, the offset
1536 does not include as yet unused buffered input. This information can be used
1537 for a progress indicator. On error, gzoffset() returns -1.
1538 */
1539
1540 ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1541 /*
1542 Returns true (1) if the end-of-file indicator has been set while reading,
1543 false (0) otherwise. Note that the end-of-file indicator is set only if the
1544 read tried to go past the end of the input, but came up short. Therefore,
1545 just like feof(), gzeof() may return false even if there is no more data to
1546 read, in the event that the last read request was for the exact number of
1547 bytes remaining in the input file. This will happen if the input file size
1548 is an exact multiple of the buffer size.
1549
1550 If gzeof() returns true, then the read functions will return no more data,
1551 unless the end-of-file indicator is reset by gzclearerr() and the input file
1552 has grown since the previous end of file was detected.
1553 */
1554
1555 ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1556 /*
1557 Returns true (1) if file is being copied directly while reading, or false
1558 (0) if file is a gzip stream being decompressed.
1559
1560 If the input file is empty, gzdirect() will return true, since the input
1561 does not contain a gzip stream.
1562
1563 If gzdirect() is used immediately after gzopen() or gzdopen() it will
1564 cause buffers to be allocated to allow reading the file to determine if it
1565 is a gzip file. Therefore if gzbuffer() is used, it should be called before
1566 gzdirect().
1567
1568 When writing, gzdirect() returns true (1) if transparent writing was
1569 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note:
1570 gzdirect() is not needed when writing. Transparent writing must be
1571 explicitly requested, so the application already knows the answer. When
1572 linking statically, using gzdirect() will include all of the zlib code for
1573 gzip file reading and decompression, which may not be desired.)
1574 */
1575
1576 ZEXTERN int ZEXPORT gzclose OF((gzFile file));
1577 /*
1578 Flushes all pending output if necessary, closes the compressed file and
1579 deallocates the (de)compression state. Note that once file is closed, you
1580 cannot call gzerror with file, since its structures have been deallocated.
1581 gzclose must not be called more than once on the same file, just as free
1582 must not be called more than once on the same allocation.
1583
1584 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
1585 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
1586 last read ended in the middle of a gzip stream, or Z_OK on success.
1587 */
1588
1589 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
1590 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
1591 /*
1592 Same as gzclose(), but gzclose_r() is only for use when reading, and
1593 gzclose_w() is only for use when writing or appending. The advantage to
1594 using these instead of gzclose() is that they avoid linking in zlib
1595 compression or decompression code that is not used when only reading or only
1596 writing respectively. If gzclose() is used, then both compression and
1597 decompression code will be included the application when linking to a static
1598 zlib library.
1599 */
1600
1601 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1602 /*
1603 Returns the error message for the last error which occurred on the given
1604 compressed file. errnum is set to zlib error number. If an error occurred
1605 in the file system and not in the compression library, errnum is set to
1606 Z_ERRNO and the application may consult errno to get the exact error code.
1607
1608 The application must not modify the returned string. Future calls to
1609 this function may invalidate the previously returned string. If file is
1610 closed, then the string previously returned by gzerror will no longer be
1611 available.
1612
1613 gzerror() should be used to distinguish errors from end-of-file for those
1614 functions above that do not distinguish those cases in their return values.
1615 */
1616
1617 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1618 /*
1619 Clears the error and end-of-file flags for file. This is analogous to the
1620 clearerr() function in stdio. This is useful for continuing to read a gzip
1621 file that is being written concurrently.
1622 */
1623
1624 #endif /* !Z_SOLO */
1625
1626 /* checksum functions */
1627
1628 /*
1629 These functions are not related to compression but are exported
1630 anyway because they might be useful in applications using the compression
1631 library.
1632 */
1633
1634 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1635 /*
1636 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1637 return the updated checksum. If buf is Z_NULL, this function returns the
1638 required initial value for the checksum.
1639
1640 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1641 much faster.
1642
1643 Usage example:
1644
1645 uLong adler = adler32(0L, Z_NULL, 0);
1646
1647 while (read_buffer(buffer, length) != EOF) {
1648 adler = adler32(adler, buffer, length);
1649 }
1650 if (adler != original_adler) error();
1651 */
1652
1653 /*
1654 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1655 z_off_t len2));
1656
1657 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
1658 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1659 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
1660 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note
1661 that the z_off_t type (like off_t) is a signed integer. If len2 is
1662 negative, the result has no meaning or utility.
1663 */
1664
1665 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
1666 /*
1667 Update a running CRC-32 with the bytes buf[0..len-1] and return the
1668 updated CRC-32. If buf is Z_NULL, this function returns the required
1669 initial value for the crc. Pre- and post-conditioning (one's complement) is
1670 performed within this function so it shouldn't be done by the application.
1671
1672 Usage example:
1673
1674 uLong crc = crc32(0L, Z_NULL, 0);
1675
1676 while (read_buffer(buffer, length) != EOF) {
1677 crc = crc32(crc, buffer, length);
1678 }
1679 if (crc != original_crc) error();
1680 */
1681
1682 /*
1683 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1684
1685 Combine two CRC-32 check values into one. For two sequences of bytes,
1686 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1687 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1688 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1689 len2.
1690 */
1691
1692
1693 /* various hacks, don't look :) */
1694
1695 /* deflateInit and inflateInit are macros to allow checking the zlib version
1696 * and the compiler's view of z_stream:
1697 */
1698 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1699 const char *version, int stream_size));
1700 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1701 const char *version, int stream_size));
1702 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1703 int windowBits, int memLevel,
1704 int strategy, const char *version,
1705 int stream_size));
1706 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
1707 const char *version, int stream_size));
1708 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1709 unsigned char FAR *window,
1710 const char *version,
1711 int stream_size));
1712 #define deflateInit(strm, level) \
1713 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1714 #define inflateInit(strm) \
1715 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1716 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1717 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1718 (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1719 #define inflateInit2(strm, windowBits) \
1720 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1721 (int)sizeof(z_stream))
1722 #define inflateBackInit(strm, windowBits, window) \
1723 inflateBackInit_((strm), (windowBits), (window), \
1724 ZLIB_VERSION, (int)sizeof(z_stream))
1725
1726 #ifndef Z_SOLO
1727
1728 /* gzgetc() macro and its supporting function and exposed data structure. Note
1729 * that the real internal state is much larger than the exposed structure.
1730 * This abbreviated structure exposes just enough for the gzgetc() macro. The
1731 * user should not mess with these exposed elements, since their names or
1732 * behavior could change in the future, perhaps even capriciously. They can
1733 * only be used by the gzgetc() macro. You have been warned.
1734 */
1735 struct gzFile_s {
1736 unsigned have;
1737 unsigned char *next;
1738 z_off64_t pos;
1739 };
1740 ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */
1741 #ifdef Z_PREFIX_SET
1742 # undef z_gzgetc
1743 # define z_gzgetc(g) \
1744 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
1745 #else
1746 # define gzgetc(g) \
1747 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
1748 #endif
1749
1750 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1751 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
1752 * both are true, the application gets the *64 functions, and the regular
1753 * functions are changed to 64 bits) -- in case these are set on systems
1754 * without large file support, _LFS64_LARGEFILE must also be true
1755 */
1756 #ifdef Z_LARGE64
1757 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1758 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
1759 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
1760 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
1761 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
1762 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
1763 #endif
1764
1765 #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
1766 # ifdef Z_PREFIX_SET
1767 # define z_gzopen z_gzopen64
1768 # define z_gzseek z_gzseek64
1769 # define z_gztell z_gztell64
1770 # define z_gzoffset z_gzoffset64
1771 # define z_adler32_combine z_adler32_combine64
1772 # define z_crc32_combine z_crc32_combine64
1773 # else
1774 # define gzopen gzopen64
1775 # define gzseek gzseek64
1776 # define gztell gztell64
1777 # define gzoffset gzoffset64
1778 # define adler32_combine adler32_combine64
1779 # define crc32_combine crc32_combine64
1780 # endif
1781 # ifndef Z_LARGE64
1782 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1783 ZEXTERN off64_t ZEXPORT gzseek64 OF((gzFile, off64_t, int));
1784 ZEXTERN off64_t ZEXPORT gztell64 OF((gzFile));
1785 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
1786 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, off64_t));
1787 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, off64_t));
1788 # endif
1789 #else
1790 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
1791 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
1792 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
1793 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
1794 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1795 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1796 #endif
1797
1798 #else /* Z_SOLO */
1799
1800 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1801 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1802
1803 #endif /* !Z_SOLO */
1804
1805 /* hack for buggy compilers */
1806 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1807 struct internal_state {int dummy;};
1808 #endif
1809
1810 /* undocumented functions */
1811 ZEXTERN const char * ZEXPORT zError OF((int));
1812 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
1813 ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void));
1814 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
1815 ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp));
1816 ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp));
1817 #if defined(_WIN32) && !defined(Z_SOLO)
1818 ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path,
1819 const char *mode));
1820 #endif
1821 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
1822 # ifndef Z_SOLO
1823 ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file,
1824 const char *format,
1825 va_list va));
1826 # endif
1827 #endif
1828
1829 #ifdef __cplusplus
1830 }
1831 #endif
1832
1833 #endif /* ZLIB_H */
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