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zlib.h
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1/* zlib.h -- interface of the 'zlib' general purpose compression library
2 version 1.2.13, October 13th, 2022
3
4 Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler
5
6 This software is provided 'as-is', without any express or implied
7 warranty. In no event will the authors be held liable for any damages
8 arising from the use of this software.
9
10 Permission is granted to anyone to use this software for any purpose,
11 including commercial applications, and to alter it and redistribute it
12 freely, subject to the following restrictions:
13
14 1. The origin of this software must not be misrepresented; you must not
15 claim that you wrote the original software. If you use this software
16 in a product, an acknowledgment in the product documentation would be
17 appreciated but is not required.
18 2. Altered source versions must be plainly marked as such, and must not be
19 misrepresented as being the original software.
20 3. This notice may not be removed or altered from any source distribution.
21
22 Jean-loup Gailly Mark Adler
23 jloup@gzip.org madler@alumni.caltech.edu
24
25
26 The data format used by the zlib library is described by RFCs (Request for
27 Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
28 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
29*/
30
31#ifndef ZLIB_H
32#define ZLIB_H
33
34#include "zconf.h"
35
36#ifdef __cplusplus
37extern "C" {
38#endif
39
40#define ZLIB_VERSION "1.2.13"
41#define ZLIB_VERNUM 0x12d0
42#define ZLIB_VER_MAJOR 1
43#define ZLIB_VER_MINOR 2
44#define ZLIB_VER_REVISION 13
45#define ZLIB_VER_SUBREVISION 0
46
47/*
48 The 'zlib' compression library provides in-memory compression and
49 decompression functions, including integrity checks of the uncompressed data.
50 This version of the library supports only one compression method (deflation)
51 but other algorithms will be added later and will have the same stream
52 interface.
53
54 Compression can be done in a single step if the buffers are large enough,
55 or can be done by repeated calls of the compression function. In the latter
56 case, the application must provide more input and/or consume the output
57 (providing more output space) before each call.
58
59 The compressed data format used by default by the in-memory functions is
60 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
61 around a deflate stream, which is itself documented in RFC 1951.
62
63 The library also supports reading and writing files in gzip (.gz) format
64 with an interface similar to that of stdio using the functions that start
65 with "gz". The gzip format is different from the zlib format. gzip is a
66 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
67
68 This library can optionally read and write gzip and raw deflate streams in
69 memory as well.
70
71 The zlib format was designed to be compact and fast for use in memory
72 and on communications channels. The gzip format was designed for single-
73 file compression on file systems, has a larger header than zlib to maintain
74 directory information, and uses a different, slower check method than zlib.
75
76 The library does not install any signal handler. The decoder checks
77 the consistency of the compressed data, so the library should never crash
78 even in the case of corrupted input.
79*/
80
81typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
82typedef void (*free_func) OF((voidpf opaque, voidpf address));
83
84struct internal_state;
85
86typedef struct z_stream_s {
87 z_const Bytef *next_in; /* next input byte */
88 uInt avail_in; /* number of bytes available at next_in */
89 uLong total_in; /* total number of input bytes read so far */
90
91 Bytef *next_out; /* next output byte will go here */
92 uInt avail_out; /* remaining free space at next_out */
93 uLong total_out; /* total number of bytes output so far */
94
95 z_const char *msg; /* last error message, NULL if no error */
96 struct internal_state FAR *state; /* not visible by applications */
97
98 alloc_func zalloc; /* used to allocate the internal state */
99 free_func zfree; /* used to free the internal state */
100 voidpf opaque; /* private data object passed to zalloc and zfree */
101
102 int data_type; /* best guess about the data type: binary or text
103 for deflate, or the decoding state for inflate */
104 uLong adler; /* Adler-32 or CRC-32 value of the uncompressed data */
105 uLong reserved; /* reserved for future use */
107
109
110/*
111 gzip header information passed to and from zlib routines. See RFC 1952
112 for more details on the meanings of these fields.
113*/
114typedef struct gz_header_s {
115 int text; /* true if compressed data believed to be text */
116 uLong time; /* modification time */
117 int xflags; /* extra flags (not used when writing a gzip file) */
118 int os; /* operating system */
119 Bytef *extra; /* pointer to extra field or Z_NULL if none */
120 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
121 uInt extra_max; /* space at extra (only when reading header) */
122 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
123 uInt name_max; /* space at name (only when reading header) */
124 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
125 uInt comm_max; /* space at comment (only when reading header) */
126 int hcrc; /* true if there was or will be a header crc */
127 int done; /* true when done reading gzip header (not used
128 when writing a gzip file) */
130
132
133/*
134 The application must update next_in and avail_in when avail_in has dropped
135 to zero. It must update next_out and avail_out when avail_out has dropped
136 to zero. The application must initialize zalloc, zfree and opaque before
137 calling the init function. All other fields are set by the compression
138 library and must not be updated by the application.
139
140 The opaque value provided by the application will be passed as the first
141 parameter for calls of zalloc and zfree. This can be useful for custom
142 memory management. The compression library attaches no meaning to the
143 opaque value.
144
145 zalloc must return Z_NULL if there is not enough memory for the object.
146 If zlib is used in a multi-threaded application, zalloc and zfree must be
147 thread safe. In that case, zlib is thread-safe. When zalloc and zfree are
148 Z_NULL on entry to the initialization function, they are set to internal
149 routines that use the standard library functions malloc() and free().
150
151 On 16-bit systems, the functions zalloc and zfree must be able to allocate
152 exactly 65536 bytes, but will not be required to allocate more than this if
153 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
154 returned by zalloc for objects of exactly 65536 bytes *must* have their
155 offset normalized to zero. The default allocation function provided by this
156 library ensures this (see zutil.c). To reduce memory requirements and avoid
157 any allocation of 64K objects, at the expense of compression ratio, compile
158 the library with -DMAX_WBITS=14 (see zconf.h).
159
160 The fields total_in and total_out can be used for statistics or progress
161 reports. After compression, total_in holds the total size of the
162 uncompressed data and may be saved for use by the decompressor (particularly
163 if the decompressor wants to decompress everything in a single step).
164*/
165
166 /* constants */
167
168#define Z_NO_FLUSH 0
169#define Z_PARTIAL_FLUSH 1
170#define Z_SYNC_FLUSH 2
171#define Z_FULL_FLUSH 3
172#define Z_FINISH 4
173#define Z_BLOCK 5
174#define Z_TREES 6
175/* Allowed flush values; see deflate() and inflate() below for details */
176
177#define Z_OK 0
178#define Z_STREAM_END 1
179#define Z_NEED_DICT 2
180#define Z_ERRNO (-1)
181#define Z_STREAM_ERROR (-2)
182#define Z_DATA_ERROR (-3)
183#define Z_MEM_ERROR (-4)
184#define Z_BUF_ERROR (-5)
185#define Z_VERSION_ERROR (-6)
186/* Return codes for the compression/decompression functions. Negative values
187 * are errors, positive values are used for special but normal events.
188 */
189
190#define Z_NO_COMPRESSION 0
191#define Z_BEST_SPEED 1
192#define Z_BEST_COMPRESSION 9
193#define Z_DEFAULT_COMPRESSION (-1)
194/* compression levels */
195
196#define Z_FILTERED 1
197#define Z_HUFFMAN_ONLY 2
198#define Z_RLE 3
199#define Z_FIXED 4
200#define Z_DEFAULT_STRATEGY 0
201/* compression strategy; see deflateInit2() below for details */
202
203#define Z_BINARY 0
204#define Z_TEXT 1
205#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
206#define Z_UNKNOWN 2
207/* Possible values of the data_type field for deflate() */
208
209#define Z_DEFLATED 8
210/* The deflate compression method (the only one supported in this version) */
211
212#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
213
214#define zlib_version zlibVersion()
215/* for compatibility with versions < 1.0.2 */
216
217
218 /* basic functions */
219
220ZEXTERN const char * ZEXPORT zlibVersion OF((void));
221/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
222 If the first character differs, the library code actually used is not
223 compatible with the zlib.h header file used by the application. This check
224 is automatically made by deflateInit and inflateInit.
225 */
226
227/*
228ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
229
230 Initializes the internal stream state for compression. The fields
231 zalloc, zfree and opaque must be initialized before by the caller. If
232 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
233 allocation functions.
234
235 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
236 1 gives best speed, 9 gives best compression, 0 gives no compression at all
237 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
238 requests a default compromise between speed and compression (currently
239 equivalent to level 6).
240
241 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
242 memory, Z_STREAM_ERROR if level is not a valid compression level, or
243 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
244 with the version assumed by the caller (ZLIB_VERSION). msg is set to null
245 if there is no error message. deflateInit does not perform any compression:
246 this will be done by deflate().
247*/
248
249
250ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
251/*
252 deflate compresses as much data as possible, and stops when the input
253 buffer becomes empty or the output buffer becomes full. It may introduce
254 some output latency (reading input without producing any output) except when
255 forced to flush.
256
257 The detailed semantics are as follows. deflate performs one or both of the
258 following actions:
259
260 - Compress more input starting at next_in and update next_in and avail_in
261 accordingly. If not all input can be processed (because there is not
262 enough room in the output buffer), next_in and avail_in are updated and
263 processing will resume at this point for the next call of deflate().
264
265 - Generate more output starting at next_out and update next_out and avail_out
266 accordingly. This action is forced if the parameter flush is non zero.
267 Forcing flush frequently degrades the compression ratio, so this parameter
268 should be set only when necessary. Some output may be provided even if
269 flush is zero.
270
271 Before the call of deflate(), the application should ensure that at least
272 one of the actions is possible, by providing more input and/or consuming more
273 output, and updating avail_in or avail_out accordingly; avail_out should
274 never be zero before the call. The application can consume the compressed
275 output when it wants, for example when the output buffer is full (avail_out
276 == 0), or after each call of deflate(). If deflate returns Z_OK and with
277 zero avail_out, it must be called again after making room in the output
278 buffer because there might be more output pending. See deflatePending(),
279 which can be used if desired to determine whether or not there is more output
280 in that case.
281
282 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
283 decide how much data to accumulate before producing output, in order to
284 maximize compression.
285
286 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
287 flushed to the output buffer and the output is aligned on a byte boundary, so
288 that the decompressor can get all input data available so far. (In
289 particular avail_in is zero after the call if enough output space has been
290 provided before the call.) Flushing may degrade compression for some
291 compression algorithms and so it should be used only when necessary. This
292 completes the current deflate block and follows it with an empty stored block
293 that is three bits plus filler bits to the next byte, followed by four bytes
294 (00 00 ff ff).
295
296 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
297 output buffer, but the output is not aligned to a byte boundary. All of the
298 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
299 This completes the current deflate block and follows it with an empty fixed
300 codes block that is 10 bits long. This assures that enough bytes are output
301 in order for the decompressor to finish the block before the empty fixed
302 codes block.
303
304 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
305 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
306 seven bits of the current block are held to be written as the next byte after
307 the next deflate block is completed. In this case, the decompressor may not
308 be provided enough bits at this point in order to complete decompression of
309 the data provided so far to the compressor. It may need to wait for the next
310 block to be emitted. This is for advanced applications that need to control
311 the emission of deflate blocks.
312
313 If flush is set to Z_FULL_FLUSH, all output is flushed as with
314 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
315 restart from this point if previous compressed data has been damaged or if
316 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
317 compression.
318
319 If deflate returns with avail_out == 0, this function must be called again
320 with the same value of the flush parameter and more output space (updated
321 avail_out), until the flush is complete (deflate returns with non-zero
322 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
323 avail_out is greater than six to avoid repeated flush markers due to
324 avail_out == 0 on return.
325
326 If the parameter flush is set to Z_FINISH, pending input is processed,
327 pending output is flushed and deflate returns with Z_STREAM_END if there was
328 enough output space. If deflate returns with Z_OK or Z_BUF_ERROR, this
329 function must be called again with Z_FINISH and more output space (updated
330 avail_out) but no more input data, until it returns with Z_STREAM_END or an
331 error. After deflate has returned Z_STREAM_END, the only possible operations
332 on the stream are deflateReset or deflateEnd.
333
334 Z_FINISH can be used in the first deflate call after deflateInit if all the
335 compression is to be done in a single step. In order to complete in one
336 call, avail_out must be at least the value returned by deflateBound (see
337 below). Then deflate is guaranteed to return Z_STREAM_END. If not enough
338 output space is provided, deflate will not return Z_STREAM_END, and it must
339 be called again as described above.
340
341 deflate() sets strm->adler to the Adler-32 checksum of all input read
342 so far (that is, total_in bytes). If a gzip stream is being generated, then
343 strm->adler will be the CRC-32 checksum of the input read so far. (See
344 deflateInit2 below.)
345
346 deflate() may update strm->data_type if it can make a good guess about
347 the input data type (Z_BINARY or Z_TEXT). If in doubt, the data is
348 considered binary. This field is only for information purposes and does not
349 affect the compression algorithm in any manner.
350
351 deflate() returns Z_OK if some progress has been made (more input
352 processed or more output produced), Z_STREAM_END if all input has been
353 consumed and all output has been produced (only when flush is set to
354 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
355 if next_in or next_out was Z_NULL or the state was inadvertently written over
356 by the application), or Z_BUF_ERROR if no progress is possible (for example
357 avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and
358 deflate() can be called again with more input and more output space to
359 continue compressing.
360*/
361
362
364/*
365 All dynamically allocated data structures for this stream are freed.
366 This function discards any unprocessed input and does not flush any pending
367 output.
368
369 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
370 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
371 prematurely (some input or output was discarded). In the error case, msg
372 may be set but then points to a static string (which must not be
373 deallocated).
374*/
375
376
377/*
378ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
379
380 Initializes the internal stream state for decompression. The fields
381 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
382 the caller. In the current version of inflate, the provided input is not
383 read or consumed. The allocation of a sliding window will be deferred to
384 the first call of inflate (if the decompression does not complete on the
385 first call). If zalloc and zfree are set to Z_NULL, inflateInit updates
386 them to use default allocation functions.
387
388 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
389 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
390 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
391 invalid, such as a null pointer to the structure. msg is set to null if
392 there is no error message. inflateInit does not perform any decompression.
393 Actual decompression will be done by inflate(). So next_in, and avail_in,
394 next_out, and avail_out are unused and unchanged. The current
395 implementation of inflateInit() does not process any header information --
396 that is deferred until inflate() is called.
397*/
398
399
400ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
401/*
402 inflate decompresses as much data as possible, and stops when the input
403 buffer becomes empty or the output buffer becomes full. It may introduce
404 some output latency (reading input without producing any output) except when
405 forced to flush.
406
407 The detailed semantics are as follows. inflate performs one or both of the
408 following actions:
409
410 - Decompress more input starting at next_in and update next_in and avail_in
411 accordingly. If not all input can be processed (because there is not
412 enough room in the output buffer), then next_in and avail_in are updated
413 accordingly, and processing will resume at this point for the next call of
414 inflate().
415
416 - Generate more output starting at next_out and update next_out and avail_out
417 accordingly. inflate() provides as much output as possible, until there is
418 no more input data or no more space in the output buffer (see below about
419 the flush parameter).
420
421 Before the call of inflate(), the application should ensure that at least
422 one of the actions is possible, by providing more input and/or consuming more
423 output, and updating the next_* and avail_* values accordingly. If the
424 caller of inflate() does not provide both available input and available
425 output space, it is possible that there will be no progress made. The
426 application can consume the uncompressed output when it wants, for example
427 when the output buffer is full (avail_out == 0), or after each call of
428 inflate(). If inflate returns Z_OK and with zero avail_out, it must be
429 called again after making room in the output buffer because there might be
430 more output pending.
431
432 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
433 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
434 output as possible to the output buffer. Z_BLOCK requests that inflate()
435 stop if and when it gets to the next deflate block boundary. When decoding
436 the zlib or gzip format, this will cause inflate() to return immediately
437 after the header and before the first block. When doing a raw inflate,
438 inflate() will go ahead and process the first block, and will return when it
439 gets to the end of that block, or when it runs out of data.
440
441 The Z_BLOCK option assists in appending to or combining deflate streams.
442 To assist in this, on return inflate() always sets strm->data_type to the
443 number of unused bits in the last byte taken from strm->next_in, plus 64 if
444 inflate() is currently decoding the last block in the deflate stream, plus
445 128 if inflate() returned immediately after decoding an end-of-block code or
446 decoding the complete header up to just before the first byte of the deflate
447 stream. The end-of-block will not be indicated until all of the uncompressed
448 data from that block has been written to strm->next_out. The number of
449 unused bits may in general be greater than seven, except when bit 7 of
450 data_type is set, in which case the number of unused bits will be less than
451 eight. data_type is set as noted here every time inflate() returns for all
452 flush options, and so can be used to determine the amount of currently
453 consumed input in bits.
454
455 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
456 end of each deflate block header is reached, before any actual data in that
457 block is decoded. This allows the caller to determine the length of the
458 deflate block header for later use in random access within a deflate block.
459 256 is added to the value of strm->data_type when inflate() returns
460 immediately after reaching the end of the deflate block header.
461
462 inflate() should normally be called until it returns Z_STREAM_END or an
463 error. However if all decompression is to be performed in a single step (a
464 single call of inflate), the parameter flush should be set to Z_FINISH. In
465 this case all pending input is processed and all pending output is flushed;
466 avail_out must be large enough to hold all of the uncompressed data for the
467 operation to complete. (The size of the uncompressed data may have been
468 saved by the compressor for this purpose.) The use of Z_FINISH is not
469 required to perform an inflation in one step. However it may be used to
470 inform inflate that a faster approach can be used for the single inflate()
471 call. Z_FINISH also informs inflate to not maintain a sliding window if the
472 stream completes, which reduces inflate's memory footprint. If the stream
473 does not complete, either because not all of the stream is provided or not
474 enough output space is provided, then a sliding window will be allocated and
475 inflate() can be called again to continue the operation as if Z_NO_FLUSH had
476 been used.
477
478 In this implementation, inflate() always flushes as much output as
479 possible to the output buffer, and always uses the faster approach on the
480 first call. So the effects of the flush parameter in this implementation are
481 on the return value of inflate() as noted below, when inflate() returns early
482 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
483 memory for a sliding window when Z_FINISH is used.
484
485 If a preset dictionary is needed after this call (see inflateSetDictionary
486 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
487 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
488 strm->adler to the Adler-32 checksum of all output produced so far (that is,
489 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
490 below. At the end of the stream, inflate() checks that its computed Adler-32
491 checksum is equal to that saved by the compressor and returns Z_STREAM_END
492 only if the checksum is correct.
493
494 inflate() can decompress and check either zlib-wrapped or gzip-wrapped
495 deflate data. The header type is detected automatically, if requested when
496 initializing with inflateInit2(). Any information contained in the gzip
497 header is not retained unless inflateGetHeader() is used. When processing
498 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
499 produced so far. The CRC-32 is checked against the gzip trailer, as is the
500 uncompressed length, modulo 2^32.
501
502 inflate() returns Z_OK if some progress has been made (more input processed
503 or more output produced), Z_STREAM_END if the end of the compressed data has
504 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
505 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
506 corrupted (input stream not conforming to the zlib format or incorrect check
507 value, in which case strm->msg points to a string with a more specific
508 error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
509 next_in or next_out was Z_NULL, or the state was inadvertently written over
510 by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
511 if no progress was possible or if there was not enough room in the output
512 buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
513 inflate() can be called again with more input and more output space to
514 continue decompressing. If Z_DATA_ERROR is returned, the application may
515 then call inflateSync() to look for a good compression block if a partial
516 recovery of the data is to be attempted.
517*/
518
519
521/*
522 All dynamically allocated data structures for this stream are freed.
523 This function discards any unprocessed input and does not flush any pending
524 output.
525
526 inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state
527 was inconsistent.
528*/
529
530
531 /* Advanced functions */
532
533/*
534 The following functions are needed only in some special applications.
535*/
536
537/*
538ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
539 int level,
540 int method,
541 int windowBits,
542 int memLevel,
543 int strategy));
544
545 This is another version of deflateInit with more compression options. The
546 fields zalloc, zfree and opaque must be initialized before by the caller.
547
548 The method parameter is the compression method. It must be Z_DEFLATED in
549 this version of the library.
550
551 The windowBits parameter is the base two logarithm of the window size
552 (the size of the history buffer). It should be in the range 8..15 for this
553 version of the library. Larger values of this parameter result in better
554 compression at the expense of memory usage. The default value is 15 if
555 deflateInit is used instead.
556
557 For the current implementation of deflate(), a windowBits value of 8 (a
558 window size of 256 bytes) is not supported. As a result, a request for 8
559 will result in 9 (a 512-byte window). In that case, providing 8 to
560 inflateInit2() will result in an error when the zlib header with 9 is
561 checked against the initialization of inflate(). The remedy is to not use 8
562 with deflateInit2() with this initialization, or at least in that case use 9
563 with inflateInit2().
564
565 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
566 determines the window size. deflate() will then generate raw deflate data
567 with no zlib header or trailer, and will not compute a check value.
568
569 windowBits can also be greater than 15 for optional gzip encoding. Add
570 16 to windowBits to write a simple gzip header and trailer around the
571 compressed data instead of a zlib wrapper. The gzip header will have no
572 file name, no extra data, no comment, no modification time (set to zero), no
573 header crc, and the operating system will be set to the appropriate value,
574 if the operating system was determined at compile time. If a gzip stream is
575 being written, strm->adler is a CRC-32 instead of an Adler-32.
576
577 For raw deflate or gzip encoding, a request for a 256-byte window is
578 rejected as invalid, since only the zlib header provides a means of
579 transmitting the window size to the decompressor.
580
581 The memLevel parameter specifies how much memory should be allocated
582 for the internal compression state. memLevel=1 uses minimum memory but is
583 slow and reduces compression ratio; memLevel=9 uses maximum memory for
584 optimal speed. The default value is 8. See zconf.h for total memory usage
585 as a function of windowBits and memLevel.
586
587 The strategy parameter is used to tune the compression algorithm. Use the
588 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
589 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
590 string match), or Z_RLE to limit match distances to one (run-length
591 encoding). Filtered data consists mostly of small values with a somewhat
592 random distribution. In this case, the compression algorithm is tuned to
593 compress them better. The effect of Z_FILTERED is to force more Huffman
594 coding and less string matching; it is somewhat intermediate between
595 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
596 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
597 strategy parameter only affects the compression ratio but not the
598 correctness of the compressed output even if it is not set appropriately.
599 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
600 decoder for special applications.
601
602 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
603 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
604 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
605 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
606 set to null if there is no error message. deflateInit2 does not perform any
607 compression: this will be done by deflate().
608*/
609
611 const Bytef *dictionary,
612 uInt dictLength));
613/*
614 Initializes the compression dictionary from the given byte sequence
615 without producing any compressed output. When using the zlib format, this
616 function must be called immediately after deflateInit, deflateInit2 or
617 deflateReset, and before any call of deflate. When doing raw deflate, this
618 function must be called either before any call of deflate, or immediately
619 after the completion of a deflate block, i.e. after all input has been
620 consumed and all output has been delivered when using any of the flush
621 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The
622 compressor and decompressor must use exactly the same dictionary (see
623 inflateSetDictionary).
624
625 The dictionary should consist of strings (byte sequences) that are likely
626 to be encountered later in the data to be compressed, with the most commonly
627 used strings preferably put towards the end of the dictionary. Using a
628 dictionary is most useful when the data to be compressed is short and can be
629 predicted with good accuracy; the data can then be compressed better than
630 with the default empty dictionary.
631
632 Depending on the size of the compression data structures selected by
633 deflateInit or deflateInit2, a part of the dictionary may in effect be
634 discarded, for example if the dictionary is larger than the window size
635 provided in deflateInit or deflateInit2. Thus the strings most likely to be
636 useful should be put at the end of the dictionary, not at the front. In
637 addition, the current implementation of deflate will use at most the window
638 size minus 262 bytes of the provided dictionary.
639
640 Upon return of this function, strm->adler is set to the Adler-32 value
641 of the dictionary; the decompressor may later use this value to determine
642 which dictionary has been used by the compressor. (The Adler-32 value
643 applies to the whole dictionary even if only a subset of the dictionary is
644 actually used by the compressor.) If a raw deflate was requested, then the
645 Adler-32 value is not computed and strm->adler is not set.
646
647 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
648 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
649 inconsistent (for example if deflate has already been called for this stream
650 or if not at a block boundary for raw deflate). deflateSetDictionary does
651 not perform any compression: this will be done by deflate().
652*/
653
656 uInt *dictLength));
657/*
658 Returns the sliding dictionary being maintained by deflate. dictLength is
659 set to the number of bytes in the dictionary, and that many bytes are copied
660 to dictionary. dictionary must have enough space, where 32768 bytes is
661 always enough. If deflateGetDictionary() is called with dictionary equal to
662 Z_NULL, then only the dictionary length is returned, and nothing is copied.
663 Similarly, if dictLength is Z_NULL, then it is not set.
664
665 deflateGetDictionary() may return a length less than the window size, even
666 when more than the window size in input has been provided. It may return up
667 to 258 bytes less in that case, due to how zlib's implementation of deflate
668 manages the sliding window and lookahead for matches, where matches can be
669 up to 258 bytes long. If the application needs the last window-size bytes of
670 input, then that would need to be saved by the application outside of zlib.
671
672 deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
673 stream state is inconsistent.
674*/
675
678/*
679 Sets the destination stream as a complete copy of the source stream.
680
681 This function can be useful when several compression strategies will be
682 tried, for example when there are several ways of pre-processing the input
683 data with a filter. The streams that will be discarded should then be freed
684 by calling deflateEnd. Note that deflateCopy duplicates the internal
685 compression state which can be quite large, so this strategy is slow and can
686 consume lots of memory.
687
688 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
689 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
690 (such as zalloc being Z_NULL). msg is left unchanged in both source and
691 destination.
692*/
693
695/*
696 This function is equivalent to deflateEnd followed by deflateInit, but
697 does not free and reallocate the internal compression state. The stream
698 will leave the compression level and any other attributes that may have been
699 set unchanged.
700
701 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
702 stream state was inconsistent (such as zalloc or state being Z_NULL).
703*/
704
706 int level,
707 int strategy));
708/*
709 Dynamically update the compression level and compression strategy. The
710 interpretation of level and strategy is as in deflateInit2(). This can be
711 used to switch between compression and straight copy of the input data, or
712 to switch to a different kind of input data requiring a different strategy.
713 If the compression approach (which is a function of the level) or the
714 strategy is changed, and if there have been any deflate() calls since the
715 state was initialized or reset, then the input available so far is
716 compressed with the old level and strategy using deflate(strm, Z_BLOCK).
717 There are three approaches for the compression levels 0, 1..3, and 4..9
718 respectively. The new level and strategy will take effect at the next call
719 of deflate().
720
721 If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
722 not have enough output space to complete, then the parameter change will not
723 take effect. In this case, deflateParams() can be called again with the
724 same parameters and more output space to try again.
725
726 In order to assure a change in the parameters on the first try, the
727 deflate stream should be flushed using deflate() with Z_BLOCK or other flush
728 request until strm.avail_out is not zero, before calling deflateParams().
729 Then no more input data should be provided before the deflateParams() call.
730 If this is done, the old level and strategy will be applied to the data
731 compressed before deflateParams(), and the new level and strategy will be
732 applied to the the data compressed after deflateParams().
733
734 deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
735 state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
736 there was not enough output space to complete the compression of the
737 available input data before a change in the strategy or approach. Note that
738 in the case of a Z_BUF_ERROR, the parameters are not changed. A return
739 value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
740 retried with more output space.
741*/
742
744 int good_length,
745 int max_lazy,
746 int nice_length,
747 int max_chain));
748/*
749 Fine tune deflate's internal compression parameters. This should only be
750 used by someone who understands the algorithm used by zlib's deflate for
751 searching for the best matching string, and even then only by the most
752 fanatic optimizer trying to squeeze out the last compressed bit for their
753 specific input data. Read the deflate.c source code for the meaning of the
754 max_lazy, good_length, nice_length, and max_chain parameters.
755
756 deflateTune() can be called after deflateInit() or deflateInit2(), and
757 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
758 */
759
761 uLong sourceLen));
762/*
763 deflateBound() returns an upper bound on the compressed size after
764 deflation of sourceLen bytes. It must be called after deflateInit() or
765 deflateInit2(), and after deflateSetHeader(), if used. This would be used
766 to allocate an output buffer for deflation in a single pass, and so would be
767 called before deflate(). If that first deflate() call is provided the
768 sourceLen input bytes, an output buffer allocated to the size returned by
769 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
770 to return Z_STREAM_END. Note that it is possible for the compressed size to
771 be larger than the value returned by deflateBound() if flush options other
772 than Z_FINISH or Z_NO_FLUSH are used.
773*/
774
776 unsigned *pending,
777 int *bits));
778/*
779 deflatePending() returns the number of bytes and bits of output that have
780 been generated, but not yet provided in the available output. The bytes not
781 provided would be due to the available output space having being consumed.
782 The number of bits of output not provided are between 0 and 7, where they
783 await more bits to join them in order to fill out a full byte. If pending
784 or bits are Z_NULL, then those values are not set.
785
786 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
787 stream state was inconsistent.
788 */
789
791 int bits,
792 int value));
793/*
794 deflatePrime() inserts bits in the deflate output stream. The intent
795 is that this function is used to start off the deflate output with the bits
796 leftover from a previous deflate stream when appending to it. As such, this
797 function can only be used for raw deflate, and must be used before the first
798 deflate() call after a deflateInit2() or deflateReset(). bits must be less
799 than or equal to 16, and that many of the least significant bits of value
800 will be inserted in the output.
801
802 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
803 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
804 source stream state was inconsistent.
805*/
806
809/*
810 deflateSetHeader() provides gzip header information for when a gzip
811 stream is requested by deflateInit2(). deflateSetHeader() may be called
812 after deflateInit2() or deflateReset() and before the first call of
813 deflate(). The text, time, os, extra field, name, and comment information
814 in the provided gz_header structure are written to the gzip header (xflag is
815 ignored -- the extra flags are set according to the compression level). The
816 caller must assure that, if not Z_NULL, name and comment are terminated with
817 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
818 available there. If hcrc is true, a gzip header crc is included. Note that
819 the current versions of the command-line version of gzip (up through version
820 1.3.x) do not support header crc's, and will report that it is a "multi-part
821 gzip file" and give up.
822
823 If deflateSetHeader is not used, the default gzip header has text false,
824 the time set to zero, and os set to 255, with no extra, name, or comment
825 fields. The gzip header is returned to the default state by deflateReset().
826
827 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
828 stream state was inconsistent.
829*/
830
831/*
832ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
833 int windowBits));
834
835 This is another version of inflateInit with an extra parameter. The
836 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
837 before by the caller.
838
839 The windowBits parameter is the base two logarithm of the maximum window
840 size (the size of the history buffer). It should be in the range 8..15 for
841 this version of the library. The default value is 15 if inflateInit is used
842 instead. windowBits must be greater than or equal to the windowBits value
843 provided to deflateInit2() while compressing, or it must be equal to 15 if
844 deflateInit2() was not used. If a compressed stream with a larger window
845 size is given as input, inflate() will return with the error code
846 Z_DATA_ERROR instead of trying to allocate a larger window.
847
848 windowBits can also be zero to request that inflate use the window size in
849 the zlib header of the compressed stream.
850
851 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
852 determines the window size. inflate() will then process raw deflate data,
853 not looking for a zlib or gzip header, not generating a check value, and not
854 looking for any check values for comparison at the end of the stream. This
855 is for use with other formats that use the deflate compressed data format
856 such as zip. Those formats provide their own check values. If a custom
857 format is developed using the raw deflate format for compressed data, it is
858 recommended that a check value such as an Adler-32 or a CRC-32 be applied to
859 the uncompressed data as is done in the zlib, gzip, and zip formats. For
860 most applications, the zlib format should be used as is. Note that comments
861 above on the use in deflateInit2() applies to the magnitude of windowBits.
862
863 windowBits can also be greater than 15 for optional gzip decoding. Add
864 32 to windowBits to enable zlib and gzip decoding with automatic header
865 detection, or add 16 to decode only the gzip format (the zlib format will
866 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
867 CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see
868 below), inflate() will *not* automatically decode concatenated gzip members.
869 inflate() will return Z_STREAM_END at the end of the gzip member. The state
870 would need to be reset to continue decoding a subsequent gzip member. This
871 *must* be done if there is more data after a gzip member, in order for the
872 decompression to be compliant with the gzip standard (RFC 1952).
873
874 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
875 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
876 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
877 invalid, such as a null pointer to the structure. msg is set to null if
878 there is no error message. inflateInit2 does not perform any decompression
879 apart from possibly reading the zlib header if present: actual decompression
880 will be done by inflate(). (So next_in and avail_in may be modified, but
881 next_out and avail_out are unused and unchanged.) The current implementation
882 of inflateInit2() does not process any header information -- that is
883 deferred until inflate() is called.
884*/
885
887 const Bytef *dictionary,
888 uInt dictLength));
889/*
890 Initializes the decompression dictionary from the given uncompressed byte
891 sequence. This function must be called immediately after a call of inflate,
892 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
893 can be determined from the Adler-32 value returned by that call of inflate.
894 The compressor and decompressor must use exactly the same dictionary (see
895 deflateSetDictionary). For raw inflate, this function can be called at any
896 time to set the dictionary. If the provided dictionary is smaller than the
897 window and there is already data in the window, then the provided dictionary
898 will amend what's there. The application must insure that the dictionary
899 that was used for compression is provided.
900
901 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
902 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
903 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
904 expected one (incorrect Adler-32 value). inflateSetDictionary does not
905 perform any decompression: this will be done by subsequent calls of
906 inflate().
907*/
908
911 uInt *dictLength));
912/*
913 Returns the sliding dictionary being maintained by inflate. dictLength is
914 set to the number of bytes in the dictionary, and that many bytes are copied
915 to dictionary. dictionary must have enough space, where 32768 bytes is
916 always enough. If inflateGetDictionary() is called with dictionary equal to
917 Z_NULL, then only the dictionary length is returned, and nothing is copied.
918 Similarly, if dictLength is Z_NULL, then it is not set.
919
920 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
921 stream state is inconsistent.
922*/
923
925/*
926 Skips invalid compressed data until a possible full flush point (see above
927 for the description of deflate with Z_FULL_FLUSH) can be found, or until all
928 available input is skipped. No output is provided.
929
930 inflateSync searches for a 00 00 FF FF pattern in the compressed data.
931 All full flush points have this pattern, but not all occurrences of this
932 pattern are full flush points.
933
934 inflateSync returns Z_OK if a possible full flush point has been found,
935 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
936 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
937 In the success case, the application may save the current current value of
938 total_in which indicates where valid compressed data was found. In the
939 error case, the application may repeatedly call inflateSync, providing more
940 input each time, until success or end of the input data.
941*/
942
945/*
946 Sets the destination stream as a complete copy of the source stream.
947
948 This function can be useful when randomly accessing a large stream. The
949 first pass through the stream can periodically record the inflate state,
950 allowing restarting inflate at those points when randomly accessing the
951 stream.
952
953 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
954 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
955 (such as zalloc being Z_NULL). msg is left unchanged in both source and
956 destination.
957*/
958
960/*
961 This function is equivalent to inflateEnd followed by inflateInit,
962 but does not free and reallocate the internal decompression state. The
963 stream will keep attributes that may have been set by inflateInit2.
964
965 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
966 stream state was inconsistent (such as zalloc or state being Z_NULL).
967*/
968
970 int windowBits));
971/*
972 This function is the same as inflateReset, but it also permits changing
973 the wrap and window size requests. The windowBits parameter is interpreted
974 the same as it is for inflateInit2. If the window size is changed, then the
975 memory allocated for the window is freed, and the window will be reallocated
976 by inflate() if needed.
977
978 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
979 stream state was inconsistent (such as zalloc or state being Z_NULL), or if
980 the windowBits parameter is invalid.
981*/
982
984 int bits,
985 int value));
986/*
987 This function inserts bits in the inflate input stream. The intent is
988 that this function is used to start inflating at a bit position in the
989 middle of a byte. The provided bits will be used before any bytes are used
990 from next_in. This function should only be used with raw inflate, and
991 should be used before the first inflate() call after inflateInit2() or
992 inflateReset(). bits must be less than or equal to 16, and that many of the
993 least significant bits of value will be inserted in the input.
994
995 If bits is negative, then the input stream bit buffer is emptied. Then
996 inflatePrime() can be called again to put bits in the buffer. This is used
997 to clear out bits leftover after feeding inflate a block description prior
998 to feeding inflate codes.
999
1000 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
1001 stream state was inconsistent.
1002*/
1003
1005/*
1006 This function returns two values, one in the lower 16 bits of the return
1007 value, and the other in the remaining upper bits, obtained by shifting the
1008 return value down 16 bits. If the upper value is -1 and the lower value is
1009 zero, then inflate() is currently decoding information outside of a block.
1010 If the upper value is -1 and the lower value is non-zero, then inflate is in
1011 the middle of a stored block, with the lower value equaling the number of
1012 bytes from the input remaining to copy. If the upper value is not -1, then
1013 it is the number of bits back from the current bit position in the input of
1014 the code (literal or length/distance pair) currently being processed. In
1015 that case the lower value is the number of bytes already emitted for that
1016 code.
1017
1018 A code is being processed if inflate is waiting for more input to complete
1019 decoding of the code, or if it has completed decoding but is waiting for
1020 more output space to write the literal or match data.
1021
1022 inflateMark() is used to mark locations in the input data for random
1023 access, which may be at bit positions, and to note those cases where the
1024 output of a code may span boundaries of random access blocks. The current
1025 location in the input stream can be determined from avail_in and data_type
1026 as noted in the description for the Z_BLOCK flush parameter for inflate.
1027
1028 inflateMark returns the value noted above, or -65536 if the provided
1029 source stream state was inconsistent.
1030*/
1031
1033 gz_headerp head));
1034/*
1035 inflateGetHeader() requests that gzip header information be stored in the
1036 provided gz_header structure. inflateGetHeader() may be called after
1037 inflateInit2() or inflateReset(), and before the first call of inflate().
1038 As inflate() processes the gzip stream, head->done is zero until the header
1039 is completed, at which time head->done is set to one. If a zlib stream is
1040 being decoded, then head->done is set to -1 to indicate that there will be
1041 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
1042 used to force inflate() to return immediately after header processing is
1043 complete and before any actual data is decompressed.
1044
1045 The text, time, xflags, and os fields are filled in with the gzip header
1046 contents. hcrc is set to true if there is a header CRC. (The header CRC
1047 was valid if done is set to one.) If extra is not Z_NULL, then extra_max
1048 contains the maximum number of bytes to write to extra. Once done is true,
1049 extra_len contains the actual extra field length, and extra contains the
1050 extra field, or that field truncated if extra_max is less than extra_len.
1051 If name is not Z_NULL, then up to name_max characters are written there,
1052 terminated with a zero unless the length is greater than name_max. If
1053 comment is not Z_NULL, then up to comm_max characters are written there,
1054 terminated with a zero unless the length is greater than comm_max. When any
1055 of extra, name, or comment are not Z_NULL and the respective field is not
1056 present in the header, then that field is set to Z_NULL to signal its
1057 absence. This allows the use of deflateSetHeader() with the returned
1058 structure to duplicate the header. However if those fields are set to
1059 allocated memory, then the application will need to save those pointers
1060 elsewhere so that they can be eventually freed.
1061
1062 If inflateGetHeader is not used, then the header information is simply
1063 discarded. The header is always checked for validity, including the header
1064 CRC if present. inflateReset() will reset the process to discard the header
1065 information. The application would need to call inflateGetHeader() again to
1066 retrieve the header from the next gzip stream.
1067
1068 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
1069 stream state was inconsistent.
1070*/
1071
1072/*
1073ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
1074 unsigned char FAR *window));
1075
1076 Initialize the internal stream state for decompression using inflateBack()
1077 calls. The fields zalloc, zfree and opaque in strm must be initialized
1078 before the call. If zalloc and zfree are Z_NULL, then the default library-
1079 derived memory allocation routines are used. windowBits is the base two
1080 logarithm of the window size, in the range 8..15. window is a caller
1081 supplied buffer of that size. Except for special applications where it is
1082 assured that deflate was used with small window sizes, windowBits must be 15
1083 and a 32K byte window must be supplied to be able to decompress general
1084 deflate streams.
1085
1086 See inflateBack() for the usage of these routines.
1087
1088 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
1089 the parameters are invalid, Z_MEM_ERROR if the internal state could not be
1090 allocated, or Z_VERSION_ERROR if the version of the library does not match
1091 the version of the header file.
1092*/
1093
1094typedef unsigned (*in_func) OF((void FAR *,
1095 z_const unsigned char FAR * FAR *));
1096typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
1097
1099 in_func in, void FAR *in_desc,
1100 out_func out, void FAR *out_desc));
1101/*
1102 inflateBack() does a raw inflate with a single call using a call-back
1103 interface for input and output. This is potentially more efficient than
1104 inflate() for file i/o applications, in that it avoids copying between the
1105 output and the sliding window by simply making the window itself the output
1106 buffer. inflate() can be faster on modern CPUs when used with large
1107 buffers. inflateBack() trusts the application to not change the output
1108 buffer passed by the output function, at least until inflateBack() returns.
1109
1110 inflateBackInit() must be called first to allocate the internal state
1111 and to initialize the state with the user-provided window buffer.
1112 inflateBack() may then be used multiple times to inflate a complete, raw
1113 deflate stream with each call. inflateBackEnd() is then called to free the
1114 allocated state.
1115
1116 A raw deflate stream is one with no zlib or gzip header or trailer.
1117 This routine would normally be used in a utility that reads zip or gzip
1118 files and writes out uncompressed files. The utility would decode the
1119 header and process the trailer on its own, hence this routine expects only
1120 the raw deflate stream to decompress. This is different from the default
1121 behavior of inflate(), which expects a zlib header and trailer around the
1122 deflate stream.
1123
1124 inflateBack() uses two subroutines supplied by the caller that are then
1125 called by inflateBack() for input and output. inflateBack() calls those
1126 routines until it reads a complete deflate stream and writes out all of the
1127 uncompressed data, or until it encounters an error. The function's
1128 parameters and return types are defined above in the in_func and out_func
1129 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
1130 number of bytes of provided input, and a pointer to that input in buf. If
1131 there is no input available, in() must return zero -- buf is ignored in that
1132 case -- and inflateBack() will return a buffer error. inflateBack() will
1133 call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
1134 out() should return zero on success, or non-zero on failure. If out()
1135 returns non-zero, inflateBack() will return with an error. Neither in() nor
1136 out() are permitted to change the contents of the window provided to
1137 inflateBackInit(), which is also the buffer that out() uses to write from.
1138 The length written by out() will be at most the window size. Any non-zero
1139 amount of input may be provided by in().
1140
1141 For convenience, inflateBack() can be provided input on the first call by
1142 setting strm->next_in and strm->avail_in. If that input is exhausted, then
1143 in() will be called. Therefore strm->next_in must be initialized before
1144 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
1145 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
1146 must also be initialized, and then if strm->avail_in is not zero, input will
1147 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
1148
1149 The in_desc and out_desc parameters of inflateBack() is passed as the
1150 first parameter of in() and out() respectively when they are called. These
1151 descriptors can be optionally used to pass any information that the caller-
1152 supplied in() and out() functions need to do their job.
1153
1154 On return, inflateBack() will set strm->next_in and strm->avail_in to
1155 pass back any unused input that was provided by the last in() call. The
1156 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
1157 if in() or out() returned an error, Z_DATA_ERROR if there was a format error
1158 in the deflate stream (in which case strm->msg is set to indicate the nature
1159 of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
1160 In the case of Z_BUF_ERROR, an input or output error can be distinguished
1161 using strm->next_in which will be Z_NULL only if in() returned an error. If
1162 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1163 non-zero. (in() will always be called before out(), so strm->next_in is
1164 assured to be defined if out() returns non-zero.) Note that inflateBack()
1165 cannot return Z_OK.
1166*/
1167
1169/*
1170 All memory allocated by inflateBackInit() is freed.
1171
1172 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
1173 state was inconsistent.
1174*/
1175
1177/* Return flags indicating compile-time options.
1178
1179 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1180 1.0: size of uInt
1181 3.2: size of uLong
1182 5.4: size of voidpf (pointer)
1183 7.6: size of z_off_t
1184
1185 Compiler, assembler, and debug options:
1186 8: ZLIB_DEBUG
1187 9: ASMV or ASMINF -- use ASM code
1188 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1189 11: 0 (reserved)
1190
1191 One-time table building (smaller code, but not thread-safe if true):
1192 12: BUILDFIXED -- build static block decoding tables when needed
1193 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1194 14,15: 0 (reserved)
1195
1196 Library content (indicates missing functionality):
1197 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1198 deflate code when not needed)
1199 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1200 and decode gzip streams (to avoid linking crc code)
1201 18-19: 0 (reserved)
1202
1203 Operation variations (changes in library functionality):
1204 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1205 21: FASTEST -- deflate algorithm with only one, lowest compression level
1206 22,23: 0 (reserved)
1207
1208 The sprintf variant used by gzprintf (zero is best):
1209 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1210 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1211 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1212
1213 Remainder:
1214 27-31: 0 (reserved)
1215 */
1216
1217#ifndef Z_SOLO
1218
1219 /* utility functions */
1220
1221/*
1222 The following utility functions are implemented on top of the basic
1223 stream-oriented functions. To simplify the interface, some default options
1224 are assumed (compression level and memory usage, standard memory allocation
1225 functions). The source code of these utility functions can be modified if
1226 you need special options.
1227*/
1228
1230 const Bytef *source, uLong sourceLen));
1231/*
1232 Compresses the source buffer into the destination buffer. sourceLen is
1233 the byte length of the source buffer. Upon entry, destLen is the total size
1234 of the destination buffer, which must be at least the value returned by
1235 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1236 compressed data. compress() is equivalent to compress2() with a level
1237 parameter of Z_DEFAULT_COMPRESSION.
1238
1239 compress returns Z_OK if success, Z_MEM_ERROR if there was not
1240 enough memory, Z_BUF_ERROR if there was not enough room in the output
1241 buffer.
1242*/
1243
1245 const Bytef *source, uLong sourceLen,
1246 int level));
1247/*
1248 Compresses the source buffer into the destination buffer. The level
1249 parameter has the same meaning as in deflateInit. sourceLen is the byte
1250 length of the source buffer. Upon entry, destLen is the total size of the
1251 destination buffer, which must be at least the value returned by
1252 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1253 compressed data.
1254
1255 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1256 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1257 Z_STREAM_ERROR if the level parameter is invalid.
1258*/
1259
1261/*
1262 compressBound() returns an upper bound on the compressed size after
1263 compress() or compress2() on sourceLen bytes. It would be used before a
1264 compress() or compress2() call to allocate the destination buffer.
1265*/
1266
1267ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
1268 const Bytef *source, uLong sourceLen));
1269/*
1270 Decompresses the source buffer into the destination buffer. sourceLen is
1271 the byte length of the source buffer. Upon entry, destLen is the total size
1272 of the destination buffer, which must be large enough to hold the entire
1273 uncompressed data. (The size of the uncompressed data must have been saved
1274 previously by the compressor and transmitted to the decompressor by some
1275 mechanism outside the scope of this compression library.) Upon exit, destLen
1276 is the actual size of the uncompressed data.
1277
1278 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1279 enough memory, Z_BUF_ERROR if there was not enough room in the output
1280 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In
1281 the case where there is not enough room, uncompress() will fill the output
1282 buffer with the uncompressed data up to that point.
1283*/
1284
1286 const Bytef *source, uLong *sourceLen));
1287/*
1288 Same as uncompress, except that sourceLen is a pointer, where the
1289 length of the source is *sourceLen. On return, *sourceLen is the number of
1290 source bytes consumed.
1291*/
1292
1293 /* gzip file access functions */
1294
1295/*
1296 This library supports reading and writing files in gzip (.gz) format with
1297 an interface similar to that of stdio, using the functions that start with
1298 "gz". The gzip format is different from the zlib format. gzip is a gzip
1299 wrapper, documented in RFC 1952, wrapped around a deflate stream.
1300*/
1301
1302typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
1303
1304/*
1305ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1306
1307 Open the gzip (.gz) file at path for reading and decompressing, or
1308 compressing and writing. The mode parameter is as in fopen ("rb" or "wb")
1309 but can also include a compression level ("wb9") or a strategy: 'f' for
1310 filtered data as in "wb6f", 'h' for Huffman-only compression as in "wb1h",
1311 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression
1312 as in "wb9F". (See the description of deflateInit2 for more information
1313 about the strategy parameter.) 'T' will request transparent writing or
1314 appending with no compression and not using the gzip format.
1315
1316 "a" can be used instead of "w" to request that the gzip stream that will
1317 be written be appended to the file. "+" will result in an error, since
1318 reading and writing to the same gzip file is not supported. The addition of
1319 "x" when writing will create the file exclusively, which fails if the file
1320 already exists. On systems that support it, the addition of "e" when
1321 reading or writing will set the flag to close the file on an execve() call.
1322
1323 These functions, as well as gzip, will read and decode a sequence of gzip
1324 streams in a file. The append function of gzopen() can be used to create
1325 such a file. (Also see gzflush() for another way to do this.) When
1326 appending, gzopen does not test whether the file begins with a gzip stream,
1327 nor does it look for the end of the gzip streams to begin appending. gzopen
1328 will simply append a gzip stream to the existing file.
1329
1330 gzopen can be used to read a file which is not in gzip format; in this
1331 case gzread will directly read from the file without decompression. When
1332 reading, this will be detected automatically by looking for the magic two-
1333 byte gzip header.
1334
1335 gzopen returns NULL if the file could not be opened, if there was
1336 insufficient memory to allocate the gzFile state, or if an invalid mode was
1337 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
1338 errno can be checked to determine if the reason gzopen failed was that the
1339 file could not be opened.
1340*/
1341
1342ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1343/*
1344 Associate a gzFile with the file descriptor fd. File descriptors are
1345 obtained from calls like open, dup, creat, pipe or fileno (if the file has
1346 been previously opened with fopen). The mode parameter is as in gzopen.
1347
1348 The next call of gzclose on the returned gzFile will also close the file
1349 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
1350 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
1351 mode);. The duplicated descriptor should be saved to avoid a leak, since
1352 gzdopen does not close fd if it fails. If you are using fileno() to get the
1353 file descriptor from a FILE *, then you will have to use dup() to avoid
1354 double-close()ing the file descriptor. Both gzclose() and fclose() will
1355 close the associated file descriptor, so they need to have different file
1356 descriptors.
1357
1358 gzdopen returns NULL if there was insufficient memory to allocate the
1359 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
1360 provided, or '+' was provided), or if fd is -1. The file descriptor is not
1361 used until the next gz* read, write, seek, or close operation, so gzdopen
1362 will not detect if fd is invalid (unless fd is -1).
1363*/
1364
1366/*
1367 Set the internal buffer size used by this library's functions for file to
1368 size. The default buffer size is 8192 bytes. This function must be called
1369 after gzopen() or gzdopen(), and before any other calls that read or write
1370 the file. The buffer memory allocation is always deferred to the first read
1371 or write. Three times that size in buffer space is allocated. A larger
1372 buffer size of, for example, 64K or 128K bytes will noticeably increase the
1373 speed of decompression (reading).
1374
1375 The new buffer size also affects the maximum length for gzprintf().
1376
1377 gzbuffer() returns 0 on success, or -1 on failure, such as being called
1378 too late.
1379*/
1380
1381ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1382/*
1383 Dynamically update the compression level and strategy for file. See the
1384 description of deflateInit2 for the meaning of these parameters. Previously
1385 provided data is flushed before applying the parameter changes.
1386
1387 gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
1388 opened for writing, Z_ERRNO if there is an error writing the flushed data,
1389 or Z_MEM_ERROR if there is a memory allocation error.
1390*/
1391
1393/*
1394 Read and decompress up to len uncompressed bytes from file into buf. If
1395 the input file is not in gzip format, gzread copies the given number of
1396 bytes into the buffer directly from the file.
1397
1398 After reaching the end of a gzip stream in the input, gzread will continue
1399 to read, looking for another gzip stream. Any number of gzip streams may be
1400 concatenated in the input file, and will all be decompressed by gzread().
1401 If something other than a gzip stream is encountered after a gzip stream,
1402 that remaining trailing garbage is ignored (and no error is returned).
1403
1404 gzread can be used to read a gzip file that is being concurrently written.
1405 Upon reaching the end of the input, gzread will return with the available
1406 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
1407 gzclearerr can be used to clear the end of file indicator in order to permit
1408 gzread to be tried again. Z_OK indicates that a gzip stream was completed
1409 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the
1410 middle of a gzip stream. Note that gzread does not return -1 in the event
1411 of an incomplete gzip stream. This error is deferred until gzclose(), which
1412 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
1413 stream. Alternatively, gzerror can be used before gzclose to detect this
1414 case.
1415
1416 gzread returns the number of uncompressed bytes actually read, less than
1417 len for end of file, or -1 for error. If len is too large to fit in an int,
1418 then nothing is read, -1 is returned, and the error state is set to
1419 Z_STREAM_ERROR.
1420*/
1421
1423 gzFile file));
1424/*
1425 Read and decompress up to nitems items of size size from file into buf,
1426 otherwise operating as gzread() does. This duplicates the interface of
1427 stdio's fread(), with size_t request and return types. If the library
1428 defines size_t, then z_size_t is identical to size_t. If not, then z_size_t
1429 is an unsigned integer type that can contain a pointer.
1430
1431 gzfread() returns the number of full items read of size size, or zero if
1432 the end of the file was reached and a full item could not be read, or if
1433 there was an error. gzerror() must be consulted if zero is returned in
1434 order to determine if there was an error. If the multiplication of size and
1435 nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
1436 is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
1437
1438 In the event that the end of file is reached and only a partial item is
1439 available at the end, i.e. the remaining uncompressed data length is not a
1440 multiple of size, then the final partial item is nevertheless read into buf
1441 and the end-of-file flag is set. The length of the partial item read is not
1442 provided, but could be inferred from the result of gztell(). This behavior
1443 is the same as the behavior of fread() implementations in common libraries,
1444 but it prevents the direct use of gzfread() to read a concurrently written
1445 file, resetting and retrying on end-of-file, when size is not 1.
1446*/
1447
1449/*
1450 Compress and write the len uncompressed bytes at buf to file. gzwrite
1451 returns the number of uncompressed bytes written or 0 in case of error.
1452*/
1453
1455 z_size_t nitems, gzFile file));
1456/*
1457 Compress and write nitems items of size size from buf to file, duplicating
1458 the interface of stdio's fwrite(), with size_t request and return types. If
1459 the library defines size_t, then z_size_t is identical to size_t. If not,
1460 then z_size_t is an unsigned integer type that can contain a pointer.
1461
1462 gzfwrite() returns the number of full items written of size size, or zero
1463 if there was an error. If the multiplication of size and nitems overflows,
1464 i.e. the product does not fit in a z_size_t, then nothing is written, zero
1465 is returned, and the error state is set to Z_STREAM_ERROR.
1466*/
1467
1469/*
1470 Convert, format, compress, and write the arguments (...) to file under
1471 control of the string format, as in fprintf. gzprintf returns the number of
1472 uncompressed bytes actually written, or a negative zlib error code in case
1473 of error. The number of uncompressed bytes written is limited to 8191, or
1474 one less than the buffer size given to gzbuffer(). The caller should assure
1475 that this limit is not exceeded. If it is exceeded, then gzprintf() will
1476 return an error (0) with nothing written. In this case, there may also be a
1477 buffer overflow with unpredictable consequences, which is possible only if
1478 zlib was compiled with the insecure functions sprintf() or vsprintf(),
1479 because the secure snprintf() or vsnprintf() functions were not available.
1480 This can be determined using zlibCompileFlags().
1481*/
1482
1483ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1484/*
1485 Compress and write the given null-terminated string s to file, excluding
1486 the terminating null character.
1487
1488 gzputs returns the number of characters written, or -1 in case of error.
1489*/
1490
1491ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1492/*
1493 Read and decompress bytes from file into buf, until len-1 characters are
1494 read, or until a newline character is read and transferred to buf, or an
1495 end-of-file condition is encountered. If any characters are read or if len
1496 is one, the string is terminated with a null character. If no characters
1497 are read due to an end-of-file or len is less than one, then the buffer is
1498 left untouched.
1499
1500 gzgets returns buf which is a null-terminated string, or it returns NULL
1501 for end-of-file or in case of error. If there was an error, the contents at
1502 buf are indeterminate.
1503*/
1504
1506/*
1507 Compress and write c, converted to an unsigned char, into file. gzputc
1508 returns the value that was written, or -1 in case of error.
1509*/
1510
1512/*
1513 Read and decompress one byte from file. gzgetc returns this byte or -1
1514 in case of end of file or error. This is implemented as a macro for speed.
1515 As such, it does not do all of the checking the other functions do. I.e.
1516 it does not check to see if file is NULL, nor whether the structure file
1517 points to has been clobbered or not.
1518*/
1519
1521/*
1522 Push c back onto the stream for file to be read as the first character on
1523 the next read. At least one character of push-back is always allowed.
1524 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
1525 fail if c is -1, and may fail if a character has been pushed but not read
1526 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
1527 output buffer size of pushed characters is allowed. (See gzbuffer above.)
1528 The pushed character will be discarded if the stream is repositioned with
1529 gzseek() or gzrewind().
1530*/
1531
1533/*
1534 Flush all pending output to file. The parameter flush is as in the
1535 deflate() function. The return value is the zlib error number (see function
1536 gzerror below). gzflush is only permitted when writing.
1537
1538 If the flush parameter is Z_FINISH, the remaining data is written and the
1539 gzip stream is completed in the output. If gzwrite() is called again, a new
1540 gzip stream will be started in the output. gzread() is able to read such
1541 concatenated gzip streams.
1542
1543 gzflush should be called only when strictly necessary because it will
1544 degrade compression if called too often.
1545*/
1546
1547/*
1548ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1549 z_off_t offset, int whence));
1550
1551 Set the starting position to offset relative to whence for the next gzread
1552 or gzwrite on file. The offset represents a number of bytes in the
1553 uncompressed data stream. The whence parameter is defined as in lseek(2);
1554 the value SEEK_END is not supported.
1555
1556 If the file is opened for reading, this function is emulated but can be
1557 extremely slow. If the file is opened for writing, only forward seeks are
1558 supported; gzseek then compresses a sequence of zeroes up to the new
1559 starting position.
1560
1561 gzseek returns the resulting offset location as measured in bytes from
1562 the beginning of the uncompressed stream, or -1 in case of error, in
1563 particular if the file is opened for writing and the new starting position
1564 would be before the current position.
1565*/
1566
1568/*
1569 Rewind file. This function is supported only for reading.
1570
1571 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET).
1572*/
1573
1574/*
1575ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1576
1577 Return the starting position for the next gzread or gzwrite on file.
1578 This position represents a number of bytes in the uncompressed data stream,
1579 and is zero when starting, even if appending or reading a gzip stream from
1580 the middle of a file using gzdopen().
1581
1582 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1583*/
1584
1585/*
1586ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
1587
1588 Return the current compressed (actual) read or write offset of file. This
1589 offset includes the count of bytes that precede the gzip stream, for example
1590 when appending or when using gzdopen() for reading. When reading, the
1591 offset does not include as yet unused buffered input. This information can
1592 be used for a progress indicator. On error, gzoffset() returns -1.
1593*/
1594
1596/*
1597 Return true (1) if the end-of-file indicator for file has been set while
1598 reading, false (0) otherwise. Note that the end-of-file indicator is set
1599 only if the read tried to go past the end of the input, but came up short.
1600 Therefore, just like feof(), gzeof() may return false even if there is no
1601 more data to read, in the event that the last read request was for the exact
1602 number of bytes remaining in the input file. This will happen if the input
1603 file size is an exact multiple of the buffer size.
1604
1605 If gzeof() returns true, then the read functions will return no more data,
1606 unless the end-of-file indicator is reset by gzclearerr() and the input file
1607 has grown since the previous end of file was detected.
1608*/
1609
1611/*
1612 Return true (1) if file is being copied directly while reading, or false
1613 (0) if file is a gzip stream being decompressed.
1614
1615 If the input file is empty, gzdirect() will return true, since the input
1616 does not contain a gzip stream.
1617
1618 If gzdirect() is used immediately after gzopen() or gzdopen() it will
1619 cause buffers to be allocated to allow reading the file to determine if it
1620 is a gzip file. Therefore if gzbuffer() is used, it should be called before
1621 gzdirect().
1622
1623 When writing, gzdirect() returns true (1) if transparent writing was
1624 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note:
1625 gzdirect() is not needed when writing. Transparent writing must be
1626 explicitly requested, so the application already knows the answer. When
1627 linking statically, using gzdirect() will include all of the zlib code for
1628 gzip file reading and decompression, which may not be desired.)
1629*/
1630
1632/*
1633 Flush all pending output for file, if necessary, close file and
1634 deallocate the (de)compression state. Note that once file is closed, you
1635 cannot call gzerror with file, since its structures have been deallocated.
1636 gzclose must not be called more than once on the same file, just as free
1637 must not be called more than once on the same allocation.
1638
1639 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
1640 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
1641 last read ended in the middle of a gzip stream, or Z_OK on success.
1642*/
1643
1646/*
1647 Same as gzclose(), but gzclose_r() is only for use when reading, and
1648 gzclose_w() is only for use when writing or appending. The advantage to
1649 using these instead of gzclose() is that they avoid linking in zlib
1650 compression or decompression code that is not used when only reading or only
1651 writing respectively. If gzclose() is used, then both compression and
1652 decompression code will be included the application when linking to a static
1653 zlib library.
1654*/
1655
1656ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1657/*
1658 Return the error message for the last error which occurred on file.
1659 errnum is set to zlib error number. If an error occurred in the file system
1660 and not in the compression library, errnum is set to Z_ERRNO and the
1661 application may consult errno to get the exact error code.
1662
1663 The application must not modify the returned string. Future calls to
1664 this function may invalidate the previously returned string. If file is
1665 closed, then the string previously returned by gzerror will no longer be
1666 available.
1667
1668 gzerror() should be used to distinguish errors from end-of-file for those
1669 functions above that do not distinguish those cases in their return values.
1670*/
1671
1673/*
1674 Clear the error and end-of-file flags for file. This is analogous to the
1675 clearerr() function in stdio. This is useful for continuing to read a gzip
1676 file that is being written concurrently.
1677*/
1678
1679#endif /* !Z_SOLO */
1680
1681 /* checksum functions */
1682
1683/*
1684 These functions are not related to compression but are exported
1685 anyway because they might be useful in applications using the compression
1686 library.
1687*/
1688
1690/*
1691 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1692 return the updated checksum. An Adler-32 value is in the range of a 32-bit
1693 unsigned integer. If buf is Z_NULL, this function returns the required
1694 initial value for the checksum.
1695
1696 An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
1697 much faster.
1698
1699 Usage example:
1700
1701 uLong adler = adler32(0L, Z_NULL, 0);
1702
1703 while (read_buffer(buffer, length) != EOF) {
1704 adler = adler32(adler, buffer, length);
1705 }
1706 if (adler != original_adler) error();
1707*/
1708
1710 z_size_t len));
1711/*
1712 Same as adler32(), but with a size_t length.
1713*/
1714
1715/*
1716ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1717 z_off_t len2));
1718
1719 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
1720 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1721 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
1722 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note
1723 that the z_off_t type (like off_t) is a signed integer. If len2 is
1724 negative, the result has no meaning or utility.
1725*/
1726
1728/*
1729 Update a running CRC-32 with the bytes buf[0..len-1] and return the
1730 updated CRC-32. A CRC-32 value is in the range of a 32-bit unsigned integer.
1731 If buf is Z_NULL, this function returns the required initial value for the
1732 crc. Pre- and post-conditioning (one's complement) is performed within this
1733 function so it shouldn't be done by the application.
1734
1735 Usage example:
1736
1737 uLong crc = crc32(0L, Z_NULL, 0);
1738
1739 while (read_buffer(buffer, length) != EOF) {
1740 crc = crc32(crc, buffer, length);
1741 }
1742 if (crc != original_crc) error();
1743*/
1744
1746 z_size_t len));
1747/*
1748 Same as crc32(), but with a size_t length.
1749*/
1750
1751/*
1752ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1753
1754 Combine two CRC-32 check values into one. For two sequences of bytes,
1755 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1756 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1757 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1758 len2.
1759*/
1760
1761/*
1762ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t len2));
1763
1764 Return the operator corresponding to length len2, to be used with
1765 crc32_combine_op().
1766*/
1767
1769/*
1770 Give the same result as crc32_combine(), using op in place of len2. op is
1771 is generated from len2 by crc32_combine_gen(). This will be faster than
1772 crc32_combine() if the generated op is used more than once.
1773*/
1774
1775
1776 /* various hacks, don't look :) */
1777
1778/* deflateInit and inflateInit are macros to allow checking the zlib version
1779 * and the compiler's view of z_stream:
1780 */
1782 const char *version, int stream_size));
1784 const char *version, int stream_size));
1786 int windowBits, int memLevel,
1787 int strategy, const char *version,
1788 int stream_size));
1790 const char *version, int stream_size));
1792 unsigned char FAR *window,
1793 const char *version,
1794 int stream_size));
1795#ifdef Z_PREFIX_SET
1796# define z_deflateInit(strm, level) \
1797 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1798# define z_inflateInit(strm) \
1799 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1800# define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1801 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1802 (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1803# define z_inflateInit2(strm, windowBits) \
1804 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1805 (int)sizeof(z_stream))
1806# define z_inflateBackInit(strm, windowBits, window) \
1807 inflateBackInit_((strm), (windowBits), (window), \
1808 ZLIB_VERSION, (int)sizeof(z_stream))
1809#else
1810# define deflateInit(strm, level) \
1811 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1812# define inflateInit(strm) \
1813 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1814# define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1815 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1816 (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1817# define inflateInit2(strm, windowBits) \
1818 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1819 (int)sizeof(z_stream))
1820# define inflateBackInit(strm, windowBits, window) \
1821 inflateBackInit_((strm), (windowBits), (window), \
1822 ZLIB_VERSION, (int)sizeof(z_stream))
1823#endif
1824
1825#ifndef Z_SOLO
1826
1827/* gzgetc() macro and its supporting function and exposed data structure. Note
1828 * that the real internal state is much larger than the exposed structure.
1829 * This abbreviated structure exposes just enough for the gzgetc() macro. The
1830 * user should not mess with these exposed elements, since their names or
1831 * behavior could change in the future, perhaps even capriciously. They can
1832 * only be used by the gzgetc() macro. You have been warned.
1833 */
1834struct gzFile_s {
1835 unsigned have;
1836 unsigned char *next;
1838};
1839ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */
1840#ifdef Z_PREFIX_SET
1841# undef z_gzgetc
1842# define z_gzgetc(g) \
1843 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1844#else
1845# define gzgetc(g) \
1846 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1847#endif
1848
1849/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1850 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
1851 * both are true, the application gets the *64 functions, and the regular
1852 * functions are changed to 64 bits) -- in case these are set on systems
1853 * without large file support, _LFS64_LARGEFILE must also be true
1854 */
1855#ifdef Z_LARGE64
1856 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1863#endif
1864
1865#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
1866# ifdef Z_PREFIX_SET
1867# define z_gzopen z_gzopen64
1868# define z_gzseek z_gzseek64
1869# define z_gztell z_gztell64
1870# define z_gzoffset z_gzoffset64
1871# define z_adler32_combine z_adler32_combine64
1872# define z_crc32_combine z_crc32_combine64
1873# define z_crc32_combine_gen z_crc32_combine_gen64
1874# else
1875# define gzopen gzopen64
1876# define gzseek gzseek64
1877# define gztell gztell64
1878# define gzoffset gzoffset64
1879# define adler32_combine adler32_combine64
1880# define crc32_combine crc32_combine64
1881# define crc32_combine_gen crc32_combine_gen64
1882# endif
1883# ifndef Z_LARGE64
1884 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1891# endif
1892#else
1893 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
1900#endif
1901
1902#else /* Z_SOLO */
1903
1907
1908#endif /* !Z_SOLO */
1909
1910/* undocumented functions */
1911ZEXTERN const char * ZEXPORT zError OF((int));
1913ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void));
1919#if defined(_WIN32) && !defined(Z_SOLO)
1920ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path,
1921 const char *mode));
1922#endif
1923#if defined(STDC) || defined(Z_HAVE_STDARG_H)
1924# ifndef Z_SOLO
1925ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file,
1926 const char *format,
1927 va_list va));
1928# endif
1929#endif
1930
1931#ifdef __cplusplus
1932}
1933#endif
1934
1935#endif /* ZLIB_H */
const z_crc_t FAR *ZEXPORT get_crc_table()
Definition: crc32.c:595
unsigned long ZEXPORT crc32_z(unsigned long crc, const unsigned char FAR *buf, z_size_t len)
Definition: crc32.c:748
uLong ZEXPORT crc32_combine(uLong crc1, uLong crc2, z_off_t len2)
Definition: crc32.c:1093
uLong ZEXPORT crc32_combine64(uLong crc1, uLong crc2, z_off64_t len2)
Definition: crc32.c:1081
uLong ZEXPORT crc32_combine_op(uLong crc1, uLong crc2, uLong op)
Definition: crc32.c:1119
uLong ZEXPORT crc32_combine_gen(z_off_t len2)
Definition: crc32.c:1112
uLong ZEXPORT crc32_combine_gen64(z_off64_t len2)
Definition: crc32.c:1102
char * va_list
Definition: acmsvcex.h:78
struct outqueuenode * head
Definition: adnsresfilter.c:66
int ZEXPORT deflateSetHeader(z_streamp strm, gz_headerp head)
Definition: deflate.c:553
int ZEXPORT deflateInit_(z_streamp strm, int level, const char *version, int stream_size)
Definition: deflate.c:225
int ZEXPORT deflatePending(z_streamp strm, unsigned *pending, int *bits)
Definition: deflate.c:564
int ZEXPORT deflateCopy(z_streamp dest, z_streamp source)
Definition: deflate.c:1156
int ZEXPORT deflateSetDictionary(z_streamp strm, const Bytef *dictionary, uInt dictLength)
Definition: deflate.c:412
int ZEXPORT deflateReset(z_streamp strm)
Definition: deflate.c:541
int ZEXPORT deflateParams(z_streamp strm, int level, int strategy)
Definition: deflate.c:605
uLong ZEXPORT deflateBound(z_streamp strm, uLong sourceLen)
Definition: deflate.c:696
int ZEXPORT deflateTune(z_streamp strm, int good_length, int max_lazy, int nice_length, int max_chain)
Definition: deflate.c:654
int ZEXPORT deflatePrime(z_streamp strm, int bits, int value)
Definition: deflate.c:578
int ZEXPORT deflateGetDictionary(z_streamp strm, Bytef *dictionary, uInt *dictLength)
Definition: deflate.c:481
int ZEXPORT deflateResetKeep(z_streamp strm)
Definition: deflate.c:503
int ZEXPORT deflateInit2_(z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy, const char *version, int stream_size)
Definition: deflate.c:237
UINT op
Definition: effect.c:236
#define crc32(crc, buf, len)
Definition: inflate.c:1081
static int inflateReset2(z_streamp strm, int windowBits)
Definition: inflate.c:851
static int inflateReset(z_streamp strm)
Definition: inflate.c:839
static int inflateResetKeep(z_streamp strm)
Definition: inflate.c:815
static uLong adler32(uLong adler, const Bytef *buf, uInt len)
Definition: inflate.c:72
void(* free_func)(voidpf opaque, voidpf address)
Definition: zlib.h:54
unsigned long uLong
Definition: zlib.h:39
int inflateEnd(z_streamp strm) DECLSPEC_HIDDEN
Definition: inflate.c:1910
gz_header FAR * gz_headerp
Definition: zlib.h:103
voidpf(* alloc_func)(voidpf opaque, uInt items, uInt size)
Definition: zlib.h:53
z_stream FAR * z_streamp
Definition: zlib.h:80
void FAR * voidpf
Definition: zlib.h:42
unsigned int uInt
Definition: zlib.h:38
#define z_const
Definition: zlib.h:35
int deflate(z_streamp strm, int flush) DECLSPEC_HIDDEN
Definition: deflate.c:815
struct z_stream_s z_stream
struct gz_header_s gz_header
int deflateEnd(z_streamp strm) DECLSPEC_HIDDEN
Definition: deflate.c:1130
int inflate(z_streamp strm, int flush) DECLSPEC_HIDDEN
Definition: inflate.c:1257
Byte FAR Bytef
Definition: zlib.h:41
#define FAR
Definition: zlib.h:34
static const WCHAR version[]
Definition: asmname.c:66
unsigned int(__cdecl typeof(jpeg_read_scanlines))(struct jpeg_decompress_struct *
Definition: typeof.h:31
method
Definition: dragdrop.c:54
GLint level
Definition: gl.h:1546
GLdouble s
Definition: gl.h:2039
GLint GLint GLsizei GLsizei GLsizei GLint GLenum format
Definition: gl.h:1546
GLsizeiptr size
Definition: glext.h:5919
GLuint address
Definition: glext.h:9393
const GLubyte * c
Definition: glext.h:8905
GLenum mode
Definition: glext.h:6217
GLenum GLuint GLenum GLsizei const GLchar * buf
Definition: glext.h:7751
GLuint in
Definition: glext.h:9616
GLenum GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * bits
Definition: glext.h:10929
GLenum GLsizei len
Definition: glext.h:6722
int ZEXPORT gzclose(gzFile file)
Definition: gzclose.c:11
void ZEXPORT gzclearerr(gzFile file)
Definition: gzlib.c:555
z_off64_t ZEXPORT gzseek64(gzFile file, z_off64_t offset, int whence)
Definition: gzlib.c:368
int ZEXPORT gzrewind(gzFile file)
Definition: gzlib.c:345
z_off64_t ZEXPORT gztell64(gzFile file)
Definition: gzlib.c:457
gzFile ZEXPORT gzopen64(char *path, const char *mode) const
Definition: gzlib.c:280
z_off_t ZEXPORT gzseek(gzFile file, z_off_t offset, int whence)
Definition: gzlib.c:445
gzFile ZEXPORT gzopen(char *path, const char *mode) const
Definition: gzlib.c:272
int ZEXPORT gzeof(gzFile file)
Definition: gzlib.c:517
gzFile ZEXPORT gzdopen(int fd, const char *mode)
Definition: gzlib.c:288
z_off64_t ZEXPORT gzoffset64(gzFile file)
Definition: gzlib.c:484
const char *ZEXPORT gzerror(gzFile file, int *errnum)
Definition: gzlib.c:534
z_off_t ZEXPORT gzoffset(gzFile file)
Definition: gzlib.c:507
z_off_t ZEXPORT gztell(gzFile file)
Definition: gzlib.c:474
int ZEXPORT gzbuffer(gzFile file, unsigned size)
Definition: gzlib.c:318
int ZEXPORT gzungetc(int c, gzFile file)
Definition: gzread.c:479
int ZEXPORT gzdirect(gzFile file)
Definition: gzread.c:603
int ZEXPORT gzread(gzFile file, voidp buf, unsigned len)
Definition: gzread.c:373
int ZEXPORT gzgetc_(gzFile file)
Definition: gzread.c:472
int ZEXPORT gzclose_r(gzFile file)
Definition: gzread.c:623
char *ZEXPORT gzgets(gzFile file, char *buf, int len)
Definition: gzread.c:539
z_size_t ZEXPORT gzfread(voidp buf, z_size_t size, z_size_t nitems, gzFile file)
Definition: gzread.c:409
int ZEXPORT gzsetparams(gzFile file, int level, int strategy)
Definition: gzwrite.c:597
int ZEXPORTVA gzprintf(gzFile file, const char *format, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8, int a9, int a10, int a11, int a12, int a13, int a14, int a15, int a16, int a17, int a18, int a19, int a20)
Definition: gzwrite.c:477
int ZEXPORT gzputc(gzFile file, int c)
Definition: gzwrite.c:313
int ZEXPORT gzputs(gzFile file, const char *s)
Definition: gzwrite.c:361
int ZEXPORT gzflush(gzFile file, int flush)
Definition: gzwrite.c:565
int ZEXPORT gzclose_w(gzFile file)
Definition: gzwrite.c:639
int ZEXPORT gzwrite(gzFile file, voidpc buf, unsigned len)
Definition: gzwrite.c:255
z_size_t ZEXPORT gzfwrite(voidpc buf, z_size_t size, z_size_t nitems, gzFile file)
Definition: gzwrite.c:283
int ZEXPORT inflateBackInit_(z_streamp strm, int windowBits, unsigned char FAR *window, const char *version, int stream_size)
Definition: infback.c:28
int ZEXPORT inflateBack(z_streamp strm, in_func in, void FAR *in_desc, out_func out, void FAR *out_desc)
Definition: infback.c:251
int ZEXPORT inflateBackEnd(z_streamp strm)
Definition: infback.c:635
static IHTMLWindow2 * window
Definition: events.c:77
static char * dest
Definition: rtl.c:135
static unsigned(__cdecl *hash_bstr)(bstr_t s)
static TCHAR * items[]
Definition: page1.c:45
static FILE * out
Definition: regtests2xml.c:44
voidpf alloc_func OF((voidpf opaque, uInt items, uInt size))
Definition: zlib.h:81
struct gzFile_s * gzFile
Definition: zlib.h:1302
#define gzgetc(g)
Definition: zlib.h:1845
int const char int stream_size
Definition: zlib.h:814
int windowBits
Definition: zlib.h:813
uLong ZEXPORT compressBound(uLong sourceLen)
Definition: compress.c:81
int ZEXPORT compress2(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level)
Definition: compress.c:22
int ZEXPORT compress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
Definition: compress.c:68
unsigned long ZEXPORT inflateCodesUsed(z_streamp strm)
Definition: inflate.c:1588
int ZEXPORT inflateSetDictionary(z_streamp strm, const Bytef *dictionary, uInt dictLength)
Definition: inflate.c:1341
long ZEXPORT inflateMark(z_streamp strm)
Definition: inflate.c:1575
int ZEXPORT inflateGetDictionary(z_streamp strm, Bytef *dictionary, uInt *dictLength)
Definition: inflate.c:1318
int ZEXPORT inflateSyncPoint(z_streamp strm)
Definition: inflate.c:1485
int ZEXPORT inflatePrime(z_streamp strm, int bits, int value)
Definition: inflate.c:250
int ZEXPORT inflateGetHeader(z_streamp strm, gz_headerp head)
Definition: inflate.c:1376
int ZEXPORT inflateUndermine(z_streamp strm, int subvert)
Definition: inflate.c:1542
int ZEXPORT inflateSync(z_streamp strm)
Definition: inflate.c:1427
int ZEXPORT inflateInit2_(z_streamp strm, int windowBits, const char *version, int stream_size)
Definition: inflate.c:198
int ZEXPORT inflateInit_(z_streamp strm, const char *version, int stream_size)
Definition: inflate.c:242
int ZEXPORT inflateCopy(z_streamp dest, z_streamp source)
Definition: inflate.c:1495
int ZEXPORT inflateValidate(z_streamp strm, int check)
Definition: inflate.c:1560
static int fd
Definition: io.c:51
Definition: fci.c:127
unsigned char * next
Definition: zlib.h:1836
z_off64_t pos
Definition: zlib.h:1837
unsigned have
Definition: zlib.h:1835
Bytef * name
Definition: zlib.h:94
int os
Definition: zlib.h:90
uInt extra_len
Definition: zlib.h:92
int hcrc
Definition: zlib.h:98
int xflags
Definition: zlib.h:89
Bytef * comment
Definition: zlib.h:96
uLong time
Definition: zlib.h:88
Bytef * extra
Definition: zlib.h:91
uInt comm_max
Definition: zlib.h:97
int done
Definition: zlib.h:99
uInt extra_max
Definition: zlib.h:93
uInt name_max
Definition: zlib.h:95
int text
Definition: zlib.h:87
uInt avail_in
Definition: zlib.h:60
z_const Bytef * next_in
Definition: zlib.h:59
alloc_func zalloc
Definition: zlib.h:70
uInt avail_out
Definition: zlib.h:64
Bytef * next_out
Definition: zlib.h:63
z_const char * msg
Definition: zlib.h:67
free_func zfree
Definition: zlib.h:71
int data_type
Definition: zlib.h:74
uLong total_in
Definition: zlib.h:61
voidpf opaque
Definition: zlib.h:72
uLong total_out
Definition: zlib.h:65
struct internal_state FAR * state
Definition: zlib.h:68
uLong reserved
Definition: zlib.h:77
uLong adler
Definition: zlib.h:76
int ZEXPORT uncompress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
Definition: uncompr.c:86
int ZEXPORT uncompress2(Bytef *dest, uLongf *destLen, const Bytef *source, uLong *sourceLen)
Definition: uncompr.c:27
Definition: pdh_main.c:94
uLong FAR uLongf
Definition: zconf.h:411
#define ZEXPORT
Definition: zconf.h:386
unsigned long z_crc_t
Definition: zconf.h:437
#define ZEXTERN
Definition: zconf.h:383
Byte const * voidpc
Definition: zconf.h:418
#define z_off_t
Definition: zconf.h:517
Byte * voidp
Definition: zconf.h:420
#define Z_ARG(args)
Definition: zconf.h:303
#define z_off64_t
Definition: zconf.h:526
unsigned long z_size_t
Definition: zconf.h:253
#define ZEXPORTVA
Definition: zconf.h:389
uLong ZEXPORT adler32_combine64(uLong adler1, uLong adler2, z_off64_t len2)
Definition: adler32.c:180
uLong ZEXPORT adler32_z(uLong adler, const Bytef *buf, z_size_t len)
Definition: adler32.c:63
uLong ZEXPORT adler32_combine(uLong adler1, uLong adler2, z_off_t len2)
Definition: adler32.c:172
const char *ZEXPORT zlibVersion()
Definition: zutil.c:27
uLong ZEXPORT zlibCompileFlags()
Definition: zutil.c:32
const char *ZEXPORT zError(int err)
Definition: zutil.c:135