1/*
2 * Copyright (c) 2008 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
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25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/* zlib.h -- interface of the 'zlib' general purpose compression library
29 version 1.2.3, July 18th, 2005
30
31 Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
32
33 This software is provided 'as-is', without any express or implied
34 warranty. In no event will the authors be held liable for any damages
35 arising from the use of this software.
36
37 Permission is granted to anyone to use this software for any purpose,
38 including commercial applications, and to alter it and redistribute it
39 freely, subject to the following restrictions:
40
41 1. The origin of this software must not be misrepresented; you must not
42 claim that you wrote the original software. If you use this software
43 in a product, an acknowledgment in the product documentation would be
44 appreciated but is not required.
45 2. Altered source versions must be plainly marked as such, and must not be
46 misrepresented as being the original software.
47 3. This notice may not be removed or altered from any source distribution.
48
49 Jean-loup Gailly Mark Adler
50 jloup@gzip.org madler@alumni.caltech.edu
51
52
53 The data format used by the zlib library is described by RFCs (Request for
54 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
55 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
56*/
57
58#ifndef ZLIB_H
59#define ZLIB_H
60
61#ifdef __cplusplus
62extern "C" {
63#endif
64
65#include "zconf.h"
66
67#define ZLIB_VERSION "1.2.3"
68#define ZLIB_VERNUM 0x1230
69
70/*
71 The 'zlib' compression library provides in-memory compression and
72 decompression functions, including integrity checks of the uncompressed
73 data. This version of the library supports only one compression method
74 (deflation) but other algorithms will be added later and will have the same
75 stream interface.
76
77 Compression can be done in a single step if the buffers are large
78 enough (for example if an input file is mmap'ed), or can be done by
79 repeated calls of the compression function. In the latter case, the
80 application must provide more input and/or consume the output
81 (providing more output space) before each call.
82
83 The compressed data format used by default by the in-memory functions is
84 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
85 around a deflate stream, which is itself documented in RFC 1951.
86
87 The library also supports reading and writing files in gzip (.gz) format
88 with an interface similar to that of stdio using the functions that start
89 with "gz". The gzip format is different from the zlib format. gzip is a
90 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
91
92 This library can optionally read and write gzip streams in memory as well.
93
94 The zlib format was designed to be compact and fast for use in memory
95 and on communications channels. The gzip format was designed for single-
96 file compression on file systems, has a larger header than zlib to maintain
97 directory information, and uses a different, slower check method than zlib.
98
99 The library does not install any signal handler. The decoder checks
100 the consistency of the compressed data, so the library should never
101 crash even in case of corrupted input.
102*/
103
104typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
105typedef void (*free_func) OF((voidpf opaque, voidpf address));
106
107struct internal_state;
108
109typedef struct z_stream_s {
110 Bytef *next_in; /* next input byte */
111 uInt avail_in; /* number of bytes available at next_in */
112 uLong total_in; /* total nb of input bytes read so far */
113
114 Bytef *next_out; /* next output byte should be put there */
115 uInt avail_out; /* remaining free space at next_out */
116 uLong total_out; /* total nb of bytes output so far */
117
118 char *msg; /* last error message, NULL if no error */
119 struct internal_state FAR *state; /* not visible by applications */
120
121 alloc_func zalloc; /* used to allocate the internal state */
122 free_func zfree; /* used to free the internal state */
123 voidpf opaque; /* private data object passed to zalloc and zfree */
124
125 int data_type; /* best guess about the data type: binary or text */
126 uLong adler; /* adler32 value of the uncompressed data */
127 uLong reserved; /* reserved for future use */
128} z_stream;
129
130typedef z_stream FAR *z_streamp;
131
132/*
133 gzip header information passed to and from zlib routines. See RFC 1952
134 for more details on the meanings of these fields.
135*/
136typedef struct gz_header_s {
137 int text; /* true if compressed data believed to be text */
138 uLong time; /* modification time */
139 int xflags; /* extra flags (not used when writing a gzip file) */
140 int os; /* operating system */
141 Bytef *extra; /* pointer to extra field or Z_NULL if none */
142 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
143 uInt extra_max; /* space at extra (only when reading header) */
144 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
145 uInt name_max; /* space at name (only when reading header) */
146 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
147 uInt comm_max; /* space at comment (only when reading header) */
148 int hcrc; /* true if there was or will be a header crc */
149 int done; /* true when done reading gzip header (not used
150 when writing a gzip file) */
151} gz_header;
152
153typedef gz_header FAR *gz_headerp;
154
155/*
156 The application must update next_in and avail_in when avail_in has
157 dropped to zero. It must update next_out and avail_out when avail_out
158 has dropped to zero. The application must initialize zalloc, zfree and
159 opaque before calling the init function. All other fields are set by the
160 compression library and must not be updated by the application.
161
162 The opaque value provided by the application will be passed as the first
163 parameter for calls of zalloc and zfree. This can be useful for custom
164 memory management. The compression library attaches no meaning to the
165 opaque value.
166
167 zalloc must return Z_NULL if there is not enough memory for the object.
168 If zlib is used in a multi-threaded application, zalloc and zfree must be
169 thread safe.
170
171 On 16-bit systems, the functions zalloc and zfree must be able to allocate
172 exactly 65536 bytes, but will not be required to allocate more than this
173 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
174 pointers returned by zalloc for objects of exactly 65536 bytes *must*
175 have their offset normalized to zero. The default allocation function
176 provided by this library ensures this (see zutil.c). To reduce memory
177 requirements and avoid any allocation of 64K objects, at the expense of
178 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
179
180 The fields total_in and total_out can be used for statistics or
181 progress reports. After compression, total_in holds the total size of
182 the uncompressed data and may be saved for use in the decompressor
183 (particularly if the decompressor wants to decompress everything in
184 a single step).
185*/
186
187 /* constants */
188
189#define Z_NO_FLUSH 0
190#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
191/* 2 is a reserved value (in zlib 1.2.3, Z_PACKET_FLUSH was removed) */
192#define Z_SYNC_FLUSH 3
193#define Z_FULL_FLUSH 4
194#define Z_FINISH 5
195#define Z_BLOCK 6
196
197/* Allowed flush values; see deflate() and inflate() below for details */
198
199#define Z_OK 0
200#define Z_STREAM_END 1
201#define Z_NEED_DICT 2
202#define Z_ERRNO (-1)
203#define Z_STREAM_ERROR (-2)
204#define Z_DATA_ERROR (-3)
205#define Z_MEM_ERROR (-4)
206#define Z_BUF_ERROR (-5)
207#define Z_VERSION_ERROR (-6)
208/* Return codes for the compression/decompression functions. Negative
209 * values are errors, positive values are used for special but normal events.
210 */
211
212#define Z_NO_COMPRESSION 0
213#define Z_BEST_SPEED 1
214#define Z_BEST_COMPRESSION 9
215#define Z_DEFAULT_COMPRESSION (-1)
216/* compression levels */
217
218#define Z_FILTERED 1
219#define Z_HUFFMAN_ONLY 2
220#define Z_RLE 3
221#define Z_FIXED 4
222#define Z_DEFAULT_STRATEGY 0
223/* compression strategy; see deflateInit2() below for details */
224
225#define Z_BINARY 0
226#define Z_TEXT 1
227#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
228#define Z_UNKNOWN 2
229/* Possible values of the data_type field (though see inflate()) */
230
231#define Z_DEFLATED 8
232/* The deflate compression method (the only one supported in this version) */
233
234#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
235
236#define zlib_version zlibVersion()
237/* for compatibility with versions < 1.0.2 */
238
239 /* basic functions */
240
241ZEXTERN const char * ZEXPORT zlibVersion OF((void));
242/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
243 If the first character differs, the library code actually used is
244 not compatible with the zlib.h header file used by the application.
245 This check is automatically made by deflateInit and inflateInit.
246 */
247
248/*
249ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
250
251 Initializes the internal stream state for compression. The fields
252 zalloc, zfree and opaque must be initialized before by the caller.
253 If zalloc and zfree are set to Z_NULL, deflateInit updates them to
254 use default allocation functions.
255
256 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
257 1 gives best speed, 9 gives best compression, 0 gives no compression at
258 all (the input data is simply copied a block at a time).
259 Z_DEFAULT_COMPRESSION requests a default compromise between speed and
260 compression (currently equivalent to level 6).
261
262 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
263 enough memory, Z_STREAM_ERROR if level is not a valid compression level,
264 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
265 with the version assumed by the caller (ZLIB_VERSION).
266 msg is set to null if there is no error message. deflateInit does not
267 perform any compression: this will be done by deflate().
268*/
269
270
271ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
272/*
273 deflate compresses as much data as possible, and stops when the input
274 buffer becomes empty or the output buffer becomes full. It may introduce some
275 output latency (reading input without producing any output) except when
276 forced to flush.
277
278 The detailed semantics are as follows. deflate performs one or both of the
279 following actions:
280
281 - Compress more input starting at next_in and update next_in and avail_in
282 accordingly. If not all input can be processed (because there is not
283 enough room in the output buffer), next_in and avail_in are updated and
284 processing will resume at this point for the next call of deflate().
285
286 - Provide more output starting at next_out and update next_out and avail_out
287 accordingly. This action is forced if the parameter flush is non zero.
288 Forcing flush frequently degrades the compression ratio, so this parameter
289 should be set only when necessary (in interactive applications).
290 Some output may be provided even if flush is not set.
291
292 Before the call of deflate(), the application should ensure that at least
293 one of the actions is possible, by providing more input and/or consuming
294 more output, and updating avail_in or avail_out accordingly; avail_out
295 should never be zero before the call. The application can consume the
296 compressed output when it wants, for example when the output buffer is full
297 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
298 and with zero avail_out, it must be called again after making room in the
299 output buffer because there might be more output pending.
300
301 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
302 decide how much data to accumualte before producing output, in order to
303 maximize compression.
304
305 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
306 flushed to the output buffer and the output is aligned on a byte boundary, so
307 that the decompressor can get all input data available so far. (In particular
308 avail_in is zero after the call if enough output space has been provided
309 before the call.) Flushing may degrade compression for some compression
310 algorithms and so it should be used only when necessary.
311
312 If flush is set to Z_FULL_FLUSH, all output is flushed as with
313 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
314 restart from this point if previous compressed data has been damaged or if
315 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
316 compression.
317
318 If deflate returns with avail_out == 0, this function must be called again
319 with the same value of the flush parameter and more output space (updated
320 avail_out), until the flush is complete (deflate returns with non-zero
321 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
322 avail_out is greater than six to avoid repeated flush markers due to
323 avail_out == 0 on return.
324
325 If the parameter flush is set to Z_FINISH, pending input is processed,
326 pending output is flushed and deflate returns with Z_STREAM_END if there
327 was enough output space; if deflate returns with Z_OK, this function must be
328 called again with Z_FINISH and more output space (updated avail_out) but no
329 more input data, until it returns with Z_STREAM_END or an error. After
330 deflate has returned Z_STREAM_END, the only possible operations on the
331 stream are deflateReset or deflateEnd.
332
333 Z_FINISH can be used immediately after deflateInit if all the compression
334 is to be done in a single step. In this case, avail_out must be at least
335 the value returned by deflateBound (see below). If deflate does not return
336 Z_STREAM_END, then it must be called again as described above.
337
338 deflate() sets strm->adler to the adler32 checksum of all input read
339 so far (that is, total_in bytes).
340
341 deflate() may update strm->data_type if it can make a good guess about
342 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
343 binary. This field is only for information purposes and does not affect
344 the compression algorithm in any manner.
345
346 deflate() returns Z_OK if some progress has been made (more input
347 processed or more output produced), Z_STREAM_END if all input has been
348 consumed and all output has been produced (only when flush is set to
349 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
350 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
351 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
352 fatal, and deflate() can be called again with more input and more output
353 space to continue compressing.
354*/
355
356
357ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
358/*
359 All dynamically allocated data structures for this stream are freed.
360 This function discards any unprocessed input and does not flush any
361 pending output.
362
363 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
364 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
365 prematurely (some input or output was discarded). In the error case,
366 msg may be set but then points to a static string (which must not be
367 deallocated).
368*/
369
370
371/*
372ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
373
374 Initializes the internal stream state for decompression. The fields
375 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
376 the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
377 value depends on the compression method), inflateInit determines the
378 compression method from the zlib header and allocates all data structures
379 accordingly; otherwise the allocation will be deferred to the first call of
380 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
381 use default allocation functions.
382
383 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
384 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
385 version assumed by the caller. msg is set to null if there is no error
386 message. inflateInit does not perform any decompression apart from reading
387 the zlib header if present: this will be done by inflate(). (So next_in and
388 avail_in may be modified, but next_out and avail_out are unchanged.)
389*/
390
391
392ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
393/*
394 inflate decompresses as much data as possible, and stops when the input
395 buffer becomes empty or the output buffer becomes full. It may introduce
396 some output latency (reading input without producing any output) except when
397 forced to flush.
398
399 The detailed semantics are as follows. inflate performs one or both of the
400 following actions:
401
402 - Decompress more input starting at next_in and update next_in and avail_in
403 accordingly. If not all input can be processed (because there is not
404 enough room in the output buffer), next_in is updated and processing
405 will resume at this point for the next call of inflate().
406
407 - Provide more output starting at next_out and update next_out and avail_out
408 accordingly. inflate() provides as much output as possible, until there
409 is no more input data or no more space in the output buffer (see below
410 about the flush parameter).
411
412 Before the call of inflate(), the application should ensure that at least
413 one of the actions is possible, by providing more input and/or consuming
414 more output, and updating the next_* and avail_* values accordingly.
415 The application can consume the uncompressed output when it wants, for
416 example when the output buffer is full (avail_out == 0), or after each
417 call of inflate(). If inflate returns Z_OK and with zero avail_out, it
418 must be called again after making room in the output buffer because there
419 might be more output pending.
420
421 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
422 Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
423 output as possible to the output buffer. Z_BLOCK requests that inflate() stop
424 if and when it gets to the next deflate block boundary. When decoding the
425 zlib or gzip format, this will cause inflate() to return immediately after
426 the header and before the first block. When doing a raw inflate, inflate()
427 will go ahead and process the first block, and will return when it gets to
428 the end of that block, or when it runs out of data.
429
430 The Z_BLOCK option assists in appending to or combining deflate streams.
431 Also to assist in this, on return inflate() will set strm->data_type to the
432 number of unused bits in the last byte taken from strm->next_in, plus 64
433 if inflate() is currently decoding the last block in the deflate stream,
434 plus 128 if inflate() returned immediately after decoding an end-of-block
435 code or decoding the complete header up to just before the first byte of the
436 deflate stream. The end-of-block will not be indicated until all of the
437 uncompressed data from that block has been written to strm->next_out. The
438 number of unused bits may in general be greater than seven, except when
439 bit 7 of data_type is set, in which case the number of unused bits will be
440 less than eight.
441
442 inflate() should normally be called until it returns Z_STREAM_END or an
443 error. However if all decompression is to be performed in a single step
444 (a single call of inflate), the parameter flush should be set to
445 Z_FINISH. In this case all pending input is processed and all pending
446 output is flushed; avail_out must be large enough to hold all the
447 uncompressed data. (The size of the uncompressed data may have been saved
448 by the compressor for this purpose.) The next operation on this stream must
449 be inflateEnd to deallocate the decompression state. The use of Z_FINISH
450 is never required, but can be used to inform inflate that a faster approach
451 may be used for the single inflate() call.
452
453 In this implementation, inflate() always flushes as much output as
454 possible to the output buffer, and always uses the faster approach on the
455 first call. So the only effect of the flush parameter in this implementation
456 is on the return value of inflate(), as noted below, or when it returns early
457 because Z_BLOCK is used.
458
459 If a preset dictionary is needed after this call (see inflateSetDictionary
460 below), inflate sets strm->adler to the adler32 checksum of the dictionary
461 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
462 strm->adler to the adler32 checksum of all output produced so far (that is,
463 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
464 below. At the end of the stream, inflate() checks that its computed adler32
465 checksum is equal to that saved by the compressor and returns Z_STREAM_END
466 only if the checksum is correct.
467
468 inflate() will decompress and check either zlib-wrapped or gzip-wrapped
469 deflate data. The header type is detected automatically. Any information
470 contained in the gzip header is not retained, so applications that need that
471 information should instead use raw inflate, see inflateInit2() below, or
472 inflateBack() and perform their own processing of the gzip header and
473 trailer.
474
475 inflate() returns Z_OK if some progress has been made (more input processed
476 or more output produced), Z_STREAM_END if the end of the compressed data has
477 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
478 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
479 corrupted (input stream not conforming to the zlib format or incorrect check
480 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
481 if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
482 Z_BUF_ERROR if no progress is possible or if there was not enough room in the
483 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
484 inflate() can be called again with more input and more output space to
485 continue decompressing. If Z_DATA_ERROR is returned, the application may then
486 call inflateSync() to look for a good compression block if a partial recovery
487 of the data is desired.
488*/
489
490
491ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
492/*
493 All dynamically allocated data structures for this stream are freed.
494 This function discards any unprocessed input and does not flush any
495 pending output.
496
497 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
498 was inconsistent. In the error case, msg may be set but then points to a
499 static string (which must not be deallocated).
500*/
501
502 /* Advanced functions */
503
504/*
505 The following functions are needed only in some special applications.
506*/
507
508/*
509ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
510 int level,
511 int method,
512 int windowBits,
513 int memLevel,
514 int strategy));
515
516 This is another version of deflateInit with more compression options. The
517 fields next_in, zalloc, zfree and opaque must be initialized before by
518 the caller.
519
520 The method parameter is the compression method. It must be Z_DEFLATED in
521 this version of the library.
522
523 The windowBits parameter is the base two logarithm of the window size
524 (the size of the history buffer). It should be in the range 8..15 for this
525 version of the library. Larger values of this parameter result in better
526 compression at the expense of memory usage. The default value is 15 if
527 deflateInit is used instead.
528
529 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
530 determines the window size. deflate() will then generate raw deflate data
531 with no zlib header or trailer, and will not compute an adler32 check value.
532
533 windowBits can also be greater than 15 for optional gzip encoding. Add
534 16 to windowBits to write a simple gzip header and trailer around the
535 compressed data instead of a zlib wrapper. The gzip header will have no
536 file name, no extra data, no comment, no modification time (set to zero),
537 no header crc, and the operating system will be set to 255 (unknown). If a
538 gzip stream is being written, strm->adler is a crc32 instead of an adler32.
539
540 The memLevel parameter specifies how much memory should be allocated
541 for the internal compression state. memLevel=1 uses minimum memory but
542 is slow and reduces compression ratio; memLevel=9 uses maximum memory
543 for optimal speed. The default value is 8. See zconf.h for total memory
544 usage as a function of windowBits and memLevel.
545
546 The strategy parameter is used to tune the compression algorithm. Use the
547 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
548 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
549 string match), or Z_RLE to limit match distances to one (run-length
550 encoding). Filtered data consists mostly of small values with a somewhat
551 random distribution. In this case, the compression algorithm is tuned to
552 compress them better. The effect of Z_FILTERED is to force more Huffman
553 coding and less string matching; it is somewhat intermediate between
554 Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
555 Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
556 parameter only affects the compression ratio but not the correctness of the
557 compressed output even if it is not set appropriately. Z_FIXED prevents the
558 use of dynamic Huffman codes, allowing for a simpler decoder for special
559 applications.
560
561 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
562 memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
563 method). msg is set to null if there is no error message. deflateInit2 does
564 not perform any compression: this will be done by deflate().
565*/
566
567ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
568 const Bytef *dictionary,
569 uInt dictLength));
570/*
571 Initializes the compression dictionary from the given byte sequence
572 without producing any compressed output. This function must be called
573 immediately after deflateInit, deflateInit2 or deflateReset, before any
574 call of deflate. The compressor and decompressor must use exactly the same
575 dictionary (see inflateSetDictionary).
576
577 The dictionary should consist of strings (byte sequences) that are likely
578 to be encountered later in the data to be compressed, with the most commonly
579 used strings preferably put towards the end of the dictionary. Using a
580 dictionary is most useful when the data to be compressed is short and can be
581 predicted with good accuracy; the data can then be compressed better than
582 with the default empty dictionary.
583
584 Depending on the size of the compression data structures selected by
585 deflateInit or deflateInit2, a part of the dictionary may in effect be
586 discarded, for example if the dictionary is larger than the window size in
587 deflate or deflate2. Thus the strings most likely to be useful should be
588 put at the end of the dictionary, not at the front. In addition, the
589 current implementation of deflate will use at most the window size minus
590 262 bytes of the provided dictionary.
591
592 Upon return of this function, strm->adler is set to the adler32 value
593 of the dictionary; the decompressor may later use this value to determine
594 which dictionary has been used by the compressor. (The adler32 value
595 applies to the whole dictionary even if only a subset of the dictionary is
596 actually used by the compressor.) If a raw deflate was requested, then the
597 adler32 value is not computed and strm->adler is not set.
598
599 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
600 parameter is invalid (such as NULL dictionary) or the stream state is
601 inconsistent (for example if deflate has already been called for this stream
602 or if the compression method is bsort). deflateSetDictionary does not
603 perform any compression: this will be done by deflate().
604*/
605
606ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
607 z_streamp source));
608/*
609 Sets the destination stream as a complete copy of the source stream.
610
611 This function can be useful when several compression strategies will be
612 tried, for example when there are several ways of pre-processing the input
613 data with a filter. The streams that will be discarded should then be freed
614 by calling deflateEnd. Note that deflateCopy duplicates the internal
615 compression state which can be quite large, so this strategy is slow and
616 can consume lots of memory.
617
618 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
619 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
620 (such as zalloc being NULL). msg is left unchanged in both source and
621 destination.
622*/
623
624#if XNU_KERNEL_PRIVATE
625
626typedef int (*z_input_func) (z_streamp strm, Bytef *buf, unsigned size);
627typedef int (*z_output_func)(z_streamp strm, Bytef *buf, unsigned size);
628
629ZEXTERN int ZEXPORT deflateResetWithIO(z_streamp strm, z_input_func zinput, z_output_func zoutput);
630
631#endif /* XNU_KERNEL_PRIVATE */
632
633ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
634/*
635 This function is equivalent to deflateEnd followed by deflateInit,
636 but does not free and reallocate all the internal compression state.
637 The stream will keep the same compression level and any other attributes
638 that may have been set by deflateInit2.
639
640 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
641 stream state was inconsistent (such as zalloc or state being NULL).
642*/
643
644ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
645 int level,
646 int strategy));
647/*
648 Dynamically update the compression level and compression strategy. The
649 interpretation of level and strategy is as in deflateInit2. This can be
650 used to switch between compression and straight copy of the input data, or
651 to switch to a different kind of input data requiring a different
652 strategy. If the compression level is changed, the input available so far
653 is compressed with the old level (and may be flushed); the new level will
654 take effect only at the next call of deflate().
655
656 Before the call of deflateParams, the stream state must be set as for
657 a call of deflate(), since the currently available input may have to
658 be compressed and flushed. In particular, strm->avail_out must be non-zero.
659
660 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
661 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
662 if strm->avail_out was zero.
663*/
664
665ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
666 int good_length,
667 int max_lazy,
668 int nice_length,
669 int max_chain));
670/*
671 Fine tune deflate's internal compression parameters. This should only be
672 used by someone who understands the algorithm used by zlib's deflate for
673 searching for the best matching string, and even then only by the most
674 fanatic optimizer trying to squeeze out the last compressed bit for their
675 specific input data. Read the deflate.c source code for the meaning of the
676 max_lazy, good_length, nice_length, and max_chain parameters.
677
678 deflateTune() can be called after deflateInit() or deflateInit2(), and
679 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
680 */
681
682ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
683 uLong sourceLen));
684/*
685 deflateBound() returns an upper bound on the compressed size after
686 deflation of sourceLen bytes. It must be called after deflateInit()
687 or deflateInit2(). This would be used to allocate an output buffer
688 for deflation in a single pass, and so would be called before deflate().
689*/
690
691ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
692 int bits,
693 int value));
694/*
695 deflatePrime() inserts bits in the deflate output stream. The intent
696 is that this function is used to start off the deflate output with the
697 bits leftover from a previous deflate stream when appending to it. As such,
698 this function can only be used for raw deflate, and must be used before the
699 first deflate() call after a deflateInit2() or deflateReset(). bits must be
700 less than or equal to 16, and that many of the least significant bits of
701 value will be inserted in the output.
702
703 deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
704 stream state was inconsistent.
705*/
706
707ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
708 gz_headerp head));
709/*
710 deflateSetHeader() provides gzip header information for when a gzip
711 stream is requested by deflateInit2(). deflateSetHeader() may be called
712 after deflateInit2() or deflateReset() and before the first call of
713 deflate(). The text, time, os, extra field, name, and comment information
714 in the provided gz_header structure are written to the gzip header (xflag is
715 ignored -- the extra flags are set according to the compression level). The
716 caller must assure that, if not Z_NULL, name and comment are terminated with
717 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
718 available there. If hcrc is true, a gzip header crc is included. Note that
719 the current versions of the command-line version of gzip (up through version
720 1.3.x) do not support header crc's, and will report that it is a "multi-part
721 gzip file" and give up.
722
723 If deflateSetHeader is not used, the default gzip header has text false,
724 the time set to zero, and os set to 255, with no extra, name, or comment
725 fields. The gzip header is returned to the default state by deflateReset().
726
727 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
728 stream state was inconsistent.
729*/
730
731/*
732ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
733 int windowBits));
734
735 This is another version of inflateInit with an extra parameter. The
736 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
737 before by the caller.
738
739 The windowBits parameter is the base two logarithm of the maximum window
740 size (the size of the history buffer). It should be in the range 8..15 for
741 this version of the library. The default value is 15 if inflateInit is used
742 instead. windowBits must be greater than or equal to the windowBits value
743 provided to deflateInit2() while compressing, or it must be equal to 15 if
744 deflateInit2() was not used. If a compressed stream with a larger window
745 size is given as input, inflate() will return with the error code
746 Z_DATA_ERROR instead of trying to allocate a larger window.
747
748 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
749 determines the window size. inflate() will then process raw deflate data,
750 not looking for a zlib or gzip header, not generating a check value, and not
751 looking for any check values for comparison at the end of the stream. This
752 is for use with other formats that use the deflate compressed data format
753 such as zip. Those formats provide their own check values. If a custom
754 format is developed using the raw deflate format for compressed data, it is
755 recommended that a check value such as an adler32 or a crc32 be applied to
756 the uncompressed data as is done in the zlib, gzip, and zip formats. For
757 most applications, the zlib format should be used as is. Note that comments
758 above on the use in deflateInit2() applies to the magnitude of windowBits.
759
760 windowBits can also be greater than 15 for optional gzip decoding. Add
761 32 to windowBits to enable zlib and gzip decoding with automatic header
762 detection, or add 16 to decode only the gzip format (the zlib format will
763 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is
764 a crc32 instead of an adler32.
765
766 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
767 memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg
768 is set to null if there is no error message. inflateInit2 does not perform
769 any decompression apart from reading the zlib header if present: this will
770 be done by inflate(). (So next_in and avail_in may be modified, but next_out
771 and avail_out are unchanged.)
772*/
773
774ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
775 const Bytef *dictionary,
776 uInt dictLength));
777/*
778 Initializes the decompression dictionary from the given uncompressed byte
779 sequence. This function must be called immediately after a call of inflate,
780 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
781 can be determined from the adler32 value returned by that call of inflate.
782 The compressor and decompressor must use exactly the same dictionary (see
783 deflateSetDictionary). For raw inflate, this function can be called
784 immediately after inflateInit2() or inflateReset() and before any call of
785 inflate() to set the dictionary. The application must insure that the
786 dictionary that was used for compression is provided.
787
788 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
789 parameter is invalid (such as NULL dictionary) or the stream state is
790 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
791 expected one (incorrect adler32 value). inflateSetDictionary does not
792 perform any decompression: this will be done by subsequent calls of
793 inflate().
794*/
795
796ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
797/*
798 Skips invalid compressed data until a full flush point (see above the
799 description of deflate with Z_FULL_FLUSH) can be found, or until all
800 available input is skipped. No output is provided.
801
802 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
803 if no more input was provided, Z_DATA_ERROR if no flush point has been found,
804 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
805 case, the application may save the current current value of total_in which
806 indicates where valid compressed data was found. In the error case, the
807 application may repeatedly call inflateSync, providing more input each time,
808 until success or end of the input data.
809*/
810
811ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
812 z_streamp source));
813/*
814 Sets the destination stream as a complete copy of the source stream.
815
816 This function can be useful when randomly accessing a large stream. The
817 first pass through the stream can periodically record the inflate state,
818 allowing restarting inflate at those points when randomly accessing the
819 stream.
820
821 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
822 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
823 (such as zalloc being NULL). msg is left unchanged in both source and
824 destination.
825*/
826
827ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
828/*
829 This function is equivalent to inflateEnd followed by inflateInit,
830 but does not free and reallocate all the internal decompression state.
831 The stream will keep attributes that may have been set by inflateInit2.
832
833 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
834 stream state was inconsistent (such as zalloc or state being NULL).
835*/
836
837ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
838 int bits,
839 int value));
840/*
841 This function inserts bits in the inflate input stream. The intent is
842 that this function is used to start inflating at a bit position in the
843 middle of a byte. The provided bits will be used before any bytes are used
844 from next_in. This function should only be used with raw inflate, and
845 should be used before the first inflate() call after inflateInit2() or
846 inflateReset(). bits must be less than or equal to 16, and that many of the
847 least significant bits of value will be inserted in the input.
848
849 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
850 stream state was inconsistent.
851*/
852
853ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
854 gz_headerp head));
855/*
856 inflateGetHeader() requests that gzip header information be stored in the
857 provided gz_header structure. inflateGetHeader() may be called after
858 inflateInit2() or inflateReset(), and before the first call of inflate().
859 As inflate() processes the gzip stream, head->done is zero until the header
860 is completed, at which time head->done is set to one. If a zlib stream is
861 being decoded, then head->done is set to -1 to indicate that there will be
862 no gzip header information forthcoming. Note that Z_BLOCK can be used to
863 force inflate() to return immediately after header processing is complete
864 and before any actual data is decompressed.
865
866 The text, time, xflags, and os fields are filled in with the gzip header
867 contents. hcrc is set to true if there is a header CRC. (The header CRC
868 was valid if done is set to one.) If extra is not Z_NULL, then extra_max
869 contains the maximum number of bytes to write to extra. Once done is true,
870 extra_len contains the actual extra field length, and extra contains the
871 extra field, or that field truncated if extra_max is less than extra_len.
872 If name is not Z_NULL, then up to name_max characters are written there,
873 terminated with a zero unless the length is greater than name_max. If
874 comment is not Z_NULL, then up to comm_max characters are written there,
875 terminated with a zero unless the length is greater than comm_max. When
876 any of extra, name, or comment are not Z_NULL and the respective field is
877 not present in the header, then that field is set to Z_NULL to signal its
878 absence. This allows the use of deflateSetHeader() with the returned
879 structure to duplicate the header. However if those fields are set to
880 allocated memory, then the application will need to save those pointers
881 elsewhere so that they can be eventually freed.
882
883 If inflateGetHeader is not used, then the header information is simply
884 discarded. The header is always checked for validity, including the header
885 CRC if present. inflateReset() will reset the process to discard the header
886 information. The application would need to call inflateGetHeader() again to
887 retrieve the header from the next gzip stream.
888
889 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
890 stream state was inconsistent.
891*/
892
893/*
894ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
895 unsigned char FAR *window));
896
897 Initialize the internal stream state for decompression using inflateBack()
898 calls. The fields zalloc, zfree and opaque in strm must be initialized
899 before the call. If zalloc and zfree are Z_NULL, then the default library-
900 derived memory allocation routines are used. windowBits is the base two
901 logarithm of the window size, in the range 8..15. window is a caller
902 supplied buffer of that size. Except for special applications where it is
903 assured that deflate was used with small window sizes, windowBits must be 15
904 and a 32K byte window must be supplied to be able to decompress general
905 deflate streams.
906
907 See inflateBack() for the usage of these routines.
908
909 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
910 the paramaters are invalid, Z_MEM_ERROR if the internal state could not
911 be allocated, or Z_VERSION_ERROR if the version of the library does not
912 match the version of the header file.
913*/
914
915typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
916typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
917
918ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
919 in_func in, void FAR *in_desc,
920 out_func out, void FAR *out_desc));
921/*
922 inflateBack() does a raw inflate with a single call using a call-back
923 interface for input and output. This is more efficient than inflate() for
924 file i/o applications in that it avoids copying between the output and the
925 sliding window by simply making the window itself the output buffer. This
926 function trusts the application to not change the output buffer passed by
927 the output function, at least until inflateBack() returns.
928
929 inflateBackInit() must be called first to allocate the internal state
930 and to initialize the state with the user-provided window buffer.
931 inflateBack() may then be used multiple times to inflate a complete, raw
932 deflate stream with each call. inflateBackEnd() is then called to free
933 the allocated state.
934
935 A raw deflate stream is one with no zlib or gzip header or trailer.
936 This routine would normally be used in a utility that reads zip or gzip
937 files and writes out uncompressed files. The utility would decode the
938 header and process the trailer on its own, hence this routine expects
939 only the raw deflate stream to decompress. This is different from the
940 normal behavior of inflate(), which expects either a zlib or gzip header and
941 trailer around the deflate stream.
942
943 inflateBack() uses two subroutines supplied by the caller that are then
944 called by inflateBack() for input and output. inflateBack() calls those
945 routines until it reads a complete deflate stream and writes out all of the
946 uncompressed data, or until it encounters an error. The function's
947 parameters and return types are defined above in the in_func and out_func
948 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
949 number of bytes of provided input, and a pointer to that input in buf. If
950 there is no input available, in() must return zero--buf is ignored in that
951 case--and inflateBack() will return a buffer error. inflateBack() will call
952 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
953 should return zero on success, or non-zero on failure. If out() returns
954 non-zero, inflateBack() will return with an error. Neither in() nor out()
955 are permitted to change the contents of the window provided to
956 inflateBackInit(), which is also the buffer that out() uses to write from.
957 The length written by out() will be at most the window size. Any non-zero
958 amount of input may be provided by in().
959
960 For convenience, inflateBack() can be provided input on the first call by
961 setting strm->next_in and strm->avail_in. If that input is exhausted, then
962 in() will be called. Therefore strm->next_in must be initialized before
963 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
964 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
965 must also be initialized, and then if strm->avail_in is not zero, input will
966 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
967
968 The in_desc and out_desc parameters of inflateBack() is passed as the
969 first parameter of in() and out() respectively when they are called. These
970 descriptors can be optionally used to pass any information that the caller-
971 supplied in() and out() functions need to do their job.
972
973 On return, inflateBack() will set strm->next_in and strm->avail_in to
974 pass back any unused input that was provided by the last in() call. The
975 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
976 if in() or out() returned an error, Z_DATA_ERROR if there was a format
977 error in the deflate stream (in which case strm->msg is set to indicate the
978 nature of the error), or Z_STREAM_ERROR if the stream was not properly
979 initialized. In the case of Z_BUF_ERROR, an input or output error can be
980 distinguished using strm->next_in which will be Z_NULL only if in() returned
981 an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
982 out() returning non-zero. (in() will always be called before out(), so
983 strm->next_in is assured to be defined if out() returns non-zero.) Note
984 that inflateBack() cannot return Z_OK.
985*/
986
987ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
988/*
989 All memory allocated by inflateBackInit() is freed.
990
991 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
992 state was inconsistent.
993*/
994
995ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
996/* Return flags indicating compile-time options.
997
998 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
999 1.0: size of uInt
1000 3.2: size of uLong
1001 5.4: size of voidpf (pointer)
1002 7.6: size of z_off_t
1003
1004 Compiler, assembler, and debug options:
1005 8: DEBUG
1006 9: ASMV or ASMINF -- use ASM code
1007 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1008 11: 0 (reserved)
1009
1010 One-time table building (smaller code, but not thread-safe if true):
1011 12: BUILDFIXED -- build static block decoding tables when needed
1012 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1013 14,15: 0 (reserved)
1014
1015 Library content (indicates missing functionality):
1016 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1017 deflate code when not needed)
1018 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1019 and decode gzip streams (to avoid linking crc code)
1020 18-19: 0 (reserved)
1021
1022 Operation variations (changes in library functionality):
1023 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1024 21: FASTEST -- deflate algorithm with only one, lowest compression level
1025 22,23: 0 (reserved)
1026
1027 The sprintf variant used by gzprintf (zero is best):
1028 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1029 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1030 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1031
1032 Remainder:
1033 27-31: 0 (reserved)
1034 */
1035
1036
1037 /* utility functions */
1038
1039/*
1040 The following utility functions are implemented on top of the
1041 basic stream-oriented functions. To simplify the interface, some
1042 default options are assumed (compression level and memory usage,
1043 standard memory allocation functions). The source code of these
1044 utility functions can easily be modified if you need special options.
1045*/
1046
1047ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
1048 const Bytef *source, uLong sourceLen));
1049/*
1050 Compresses the source buffer into the destination buffer. sourceLen is
1051 the byte length of the source buffer. Upon entry, destLen is the total
1052 size of the destination buffer, which must be at least the value returned
1053 by compressBound(sourceLen). Upon exit, destLen is the actual size of the
1054 compressed buffer.
1055 This function can be used to compress a whole file at once if the
1056 input file is mmap'ed.
1057 compress returns Z_OK if success, Z_MEM_ERROR if there was not
1058 enough memory, Z_BUF_ERROR if there was not enough room in the output
1059 buffer.
1060*/
1061
1062ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
1063 const Bytef *source, uLong sourceLen,
1064 int level));
1065/*
1066 Compresses the source buffer into the destination buffer. The level
1067 parameter has the same meaning as in deflateInit. sourceLen is the byte
1068 length of the source buffer. Upon entry, destLen is the total size of the
1069 destination buffer, which must be at least the value returned by
1070 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1071 compressed buffer.
1072
1073 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1074 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1075 Z_STREAM_ERROR if the level parameter is invalid.
1076*/
1077
1078ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1079/*
1080 compressBound() returns an upper bound on the compressed size after
1081 compress() or compress2() on sourceLen bytes. It would be used before
1082 a compress() or compress2() call to allocate the destination buffer.
1083*/
1084
1085ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
1086 const Bytef *source, uLong sourceLen));
1087/*
1088 Decompresses the source buffer into the destination buffer. sourceLen is
1089 the byte length of the source buffer. Upon entry, destLen is the total
1090 size of the destination buffer, which must be large enough to hold the
1091 entire uncompressed data. (The size of the uncompressed data must have
1092 been saved previously by the compressor and transmitted to the decompressor
1093 by some mechanism outside the scope of this compression library.)
1094 Upon exit, destLen is the actual size of the compressed buffer.
1095 This function can be used to decompress a whole file at once if the
1096 input file is mmap'ed.
1097
1098 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1099 enough memory, Z_BUF_ERROR if there was not enough room in the output
1100 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
1101*/
1102
1103#if XNU_KERNEL_PRIVATE
1104
1105ZEXTERN uLong zlib_deflate_memory_size(int wbits, int memlevel);
1106
1107#endif /* XNU_KERNEL_PRIVATE */
1108
1109#if !KERNEL
1110
1111typedef voidp gzFile;
1112
1113ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1114/*
1115 Opens a gzip (.gz) file for reading or writing. The mode parameter
1116 is as in fopen ("rb" or "wb") but can also include a compression level
1117 ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
1118 Huffman only compression as in "wb1h", or 'R' for run-length encoding
1119 as in "wb1R". (See the description of deflateInit2 for more information
1120 about the strategy parameter.)
1121
1122 gzopen can be used to read a file which is not in gzip format; in this
1123 case gzread will directly read from the file without decompression.
1124
1125 gzopen returns NULL if the file could not be opened or if there was
1126 insufficient memory to allocate the (de)compression state; errno
1127 can be checked to distinguish the two cases (if errno is zero, the
1128 zlib error is Z_MEM_ERROR). */
1129
1130ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1131/*
1132 gzdopen() associates a gzFile with the file descriptor fd. File
1133 descriptors are obtained from calls like open, dup, creat, pipe or
1134 fileno (in the file has been previously opened with fopen).
1135 The mode parameter is as in gzopen.
1136 The next call of gzclose on the returned gzFile will also close the
1137 file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
1138 descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
1139 gzdopen returns NULL if there was insufficient memory to allocate
1140 the (de)compression state.
1141*/
1142
1143ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1144/*
1145 Dynamically update the compression level or strategy. See the description
1146 of deflateInit2 for the meaning of these parameters.
1147 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
1148 opened for writing.
1149*/
1150
1151ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1152/*
1153 Reads the given number of uncompressed bytes from the compressed file.
1154 If the input file was not in gzip format, gzread copies the given number
1155 of bytes into the buffer.
1156 gzread returns the number of uncompressed bytes actually read (0 for
1157 end of file, -1 for error). */
1158
1159ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
1160 voidpc buf, unsigned len));
1161/*
1162 Writes the given number of uncompressed bytes into the compressed file.
1163 gzwrite returns the number of uncompressed bytes actually written
1164 (0 in case of error).
1165*/
1166
1167ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
1168/*
1169 Converts, formats, and writes the args to the compressed file under
1170 control of the format string, as in fprintf. gzprintf returns the number of
1171 uncompressed bytes actually written (0 in case of error). The number of
1172 uncompressed bytes written is limited to 4095. The caller should assure that
1173 this limit is not exceeded. If it is exceeded, then gzprintf() will return
1174 return an error (0) with nothing written. In this case, there may also be a
1175 buffer overflow with unpredictable consequences, which is possible only if
1176 zlib was compiled with the insecure functions sprintf() or vsprintf()
1177 because the secure snprintf() or vsnprintf() functions were not available.
1178*/
1179
1180ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1181/*
1182 Writes the given null-terminated string to the compressed file, excluding
1183 the terminating null character.
1184 gzputs returns the number of characters written, or -1 in case of error.
1185*/
1186
1187ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1188/*
1189 Reads bytes from the compressed file until len-1 characters are read, or
1190 a newline character is read and transferred to buf, or an end-of-file
1191 condition is encountered. The string is then terminated with a null
1192 character.
1193 gzgets returns buf, or Z_NULL in case of error.
1194*/
1195
1196ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1197/*
1198 Writes c, converted to an unsigned char, into the compressed file.
1199 gzputc returns the value that was written, or -1 in case of error.
1200*/
1201
1202ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1203/*
1204 Reads one byte from the compressed file. gzgetc returns this byte
1205 or -1 in case of end of file or error.
1206*/
1207
1208ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1209/*
1210 Push one character back onto the stream to be read again later.
1211 Only one character of push-back is allowed. gzungetc() returns the
1212 character pushed, or -1 on failure. gzungetc() will fail if a
1213 character has been pushed but not read yet, or if c is -1. The pushed
1214 character will be discarded if the stream is repositioned with gzseek()
1215 or gzrewind().
1216*/
1217
1218ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1219/*
1220 Flushes all pending output into the compressed file. The parameter
1221 flush is as in the deflate() function. The return value is the zlib
1222 error number (see function gzerror below). gzflush returns Z_OK if
1223 the flush parameter is Z_FINISH and all output could be flushed.
1224 gzflush should be called only when strictly necessary because it can
1225 degrade compression.
1226*/
1227
1228ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1229 z_off_t offset, int whence));
1230/*
1231 Sets the starting position for the next gzread or gzwrite on the
1232 given compressed file. The offset represents a number of bytes in the
1233 uncompressed data stream. The whence parameter is defined as in lseek(2);
1234 the value SEEK_END is not supported.
1235 If the file is opened for reading, this function is emulated but can be
1236 extremely slow. If the file is opened for writing, only forward seeks are
1237 supported; gzseek then compresses a sequence of zeroes up to the new
1238 starting position.
1239
1240 gzseek returns the resulting offset location as measured in bytes from
1241 the beginning of the uncompressed stream, or -1 in case of error, in
1242 particular if the file is opened for writing and the new starting position
1243 would be before the current position.
1244*/
1245
1246ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
1247/*
1248 Rewinds the given file. This function is supported only for reading.
1249
1250 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1251*/
1252
1253ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1254/*
1255 Returns the starting position for the next gzread or gzwrite on the
1256 given compressed file. This position represents a number of bytes in the
1257 uncompressed data stream.
1258
1259 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1260*/
1261
1262ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1263/*
1264 Returns 1 when EOF has previously been detected reading the given
1265 input stream, otherwise zero.
1266*/
1267
1268ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1269/*
1270 Returns 1 if file is being read directly without decompression, otherwise
1271 zero.
1272*/
1273
1274ZEXTERN int ZEXPORT gzclose OF((gzFile file));
1275/*
1276 Flushes all pending output if necessary, closes the compressed file
1277 and deallocates all the (de)compression state. The return value is the zlib
1278 error number (see function gzerror below).
1279*/
1280
1281ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1282/*
1283 Returns the error message for the last error which occurred on the
1284 given compressed file. errnum is set to zlib error number. If an
1285 error occurred in the file system and not in the compression library,
1286 errnum is set to Z_ERRNO and the application may consult errno
1287 to get the exact error code.
1288*/
1289
1290ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1291/*
1292 Clears the error and end-of-file flags for file. This is analogous to the
1293 clearerr() function in stdio. This is useful for continuing to read a gzip
1294 file that is being written concurrently.
1295*/
1296
1297#endif /* KERNEL */
1298
1299 /* checksum functions */
1300
1301/*
1302 These functions are not related to compression but are exported
1303 anyway because they might be useful in applications using the
1304 compression library.
1305*/
1306
1307ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1308/*
1309 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1310 return the updated checksum. If buf is NULL, this function returns
1311 the required initial value for the checksum.
1312 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1313 much faster. Usage example:
1314
1315 uLong adler = adler32(0L, Z_NULL, 0);
1316
1317 while (read_buffer(buffer, length) != EOF) {
1318 adler = adler32(adler, buffer, length);
1319 }
1320 if (adler != original_adler) error();
1321*/
1322
1323ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1324 z_off_t len2));
1325/*
1326 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
1327 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1328 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
1329 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
1330*/
1331
1332ZEXTERN uLong ZEXPORT z_crc32 OF((uLong crc, const Bytef *buf, uInt len));
1333/*
1334 Update a running CRC-32 with the bytes buf[0..len-1] and return the
1335 updated CRC-32. If buf is NULL, this function returns the required initial
1336 value for the for the crc. Pre- and post-conditioning (one's complement) is
1337 performed within this function so it shouldn't be done by the application.
1338 Usage example:
1339
1340 uLong crc = crc32(0L, Z_NULL, 0);
1341
1342 while (read_buffer(buffer, length) != EOF) {
1343 crc = crc32(crc, buffer, length);
1344 }
1345 if (crc != original_crc) error();
1346*/
1347
1348ZEXTERN uLong ZEXPORT z_crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1349
1350/*
1351 Combine two CRC-32 check values into one. For two sequences of bytes,
1352 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1353 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1354 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1355 len2.
1356*/
1357
1358
1359 /* various hacks, don't look :) */
1360
1361/* deflateInit and inflateInit are macros to allow checking the zlib version
1362 * and the compiler's view of z_stream:
1363 */
1364ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1365 const char *version, int stream_size));
1366ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1367 const char *version, int stream_size));
1368ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1369 int windowBits, int memLevel,
1370 int strategy, const char *version,
1371 int stream_size));
1372ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
1373 const char *version, int stream_size));
1374ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1375 unsigned char FAR *window,
1376 const char *version,
1377 int stream_size));
1378#define deflateInit(strm, level) \
1379 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
1380#define inflateInit(strm) \
1381 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
1382#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1383 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1384 (strategy), ZLIB_VERSION, sizeof(z_stream))
1385#define inflateInit2(strm, windowBits) \
1386 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1387#define inflateBackInit(strm, windowBits, window) \
1388 inflateBackInit_((strm), (windowBits), (window), \
1389 ZLIB_VERSION, sizeof(z_stream))
1390
1391
1392#if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1393 struct internal_state {int dummy;}; /* hack for buggy compilers */
1394#endif
1395
1396ZEXTERN const char * ZEXPORT zError OF((int));
1397ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z));
1398ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
1399
1400#ifdef __cplusplus
1401}
1402#endif
1403
1404#endif /* ZLIB_H */
1405