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Jordan Demeulenaere2d505822022-08-11 17:20:14 +02001/* zlib.h -- interface of the 'zlib' general purpose compression library
2 version 1.2.12, March 11th, 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 "1.2.12"
41#define ZLIB_VERNUM 0x12c0
42#define ZLIB_VER_MAJOR 1
43#define ZLIB_VER_MINOR 2
44#define ZLIB_VER_REVISION 12
45#define ZLIB_VER_SUBREVISION 0
46
47/*
48 * In Android's NDK we have one zlib.h for all the versions.
49 * zlib users tend to use ZLIB_VERNUM to check API availability,
50 * so we need to translate __ANDROID_API__ appropriately.
51 *
52 * ZLIB_1.2.7.1 and ZLIB_1.2.9 are the only API changes in the NDK's
53 * supported range of API levels.
54 *
55 * jb-mr2-dev (18): 1.2.7 (but not 1.2.7.1, where the APIs were added!)
56 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/jb-mr2-dev/src/zlib.h
57 * kitkat-dev (19): 1.2.8
58 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/kitkat-dev/src/zlib.h
59 *
60 * oreo-mr1-dev (27): 1.2.8
61 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/oreo-mr1-dev/src/zlib.h
62 * pie-dev (28): 1.2.11
63 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/pie-dev/src/zlib.h
64 *
65 * So:
66 * >= 28 --> 1.2.11
67 * >= 19 --> 1.2.8
68 * < 19 --> 1.2.7
69 */
70#if defined(__ANDROID__)
71# if __ANDROID_API__ >= 28
72 /* Already okay. */
73# elif __ANDROID_API__ >= 19
74# undef ZLIB_VERSION
75# define ZLIB_VERSION "1.2.8"
76# undef ZLIB_VERNUM
77# define ZLIB_VERNUM 0x1280
78# undef ZLIB_VER_REVISION
79# define ZLIB_VER_REVISION 8
80# else
81# undef ZLIB_VERSION
82# define ZLIB_VERSION "1.2.6"
83# undef ZLIB_VERNUM
84# define ZLIB_VERNUM 0x1260
85# undef ZLIB_VER_REVISION
86# define ZLIB_VER_REVISION 6
87# endif
88#endif
89
90/*
91 The 'zlib' compression library provides in-memory compression and
92 decompression functions, including integrity checks of the uncompressed data.
93 This version of the library supports only one compression method (deflation)
94 but other algorithms will be added later and will have the same stream
95 interface.
96
97 Compression can be done in a single step if the buffers are large enough,
98 or can be done by repeated calls of the compression function. In the latter
99 case, the application must provide more input and/or consume the output
100 (providing more output space) before each call.
101
102 The compressed data format used by default by the in-memory functions is
103 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
104 around a deflate stream, which is itself documented in RFC 1951.
105
106 The library also supports reading and writing files in gzip (.gz) format
107 with an interface similar to that of stdio using the functions that start
108 with "gz". The gzip format is different from the zlib format. gzip is a
109 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
110
111 This library can optionally read and write gzip and raw deflate streams in
112 memory as well.
113
114 The zlib format was designed to be compact and fast for use in memory
115 and on communications channels. The gzip format was designed for single-
116 file compression on file systems, has a larger header than zlib to maintain
117 directory information, and uses a different, slower check method than zlib.
118
119 The library does not install any signal handler. The decoder checks
120 the consistency of the compressed data, so the library should never crash
121 even in the case of corrupted input.
122*/
123
124typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
125typedef void (*free_func) OF((voidpf opaque, voidpf address));
126
127struct internal_state;
128
129typedef struct z_stream_s {
130 z_const Bytef *next_in; /* next input byte */
131 uInt avail_in; /* number of bytes available at next_in */
132 uLong total_in; /* total number of input bytes read so far */
133
134 Bytef *next_out; /* next output byte will go here */
135 uInt avail_out; /* remaining free space at next_out */
136 uLong total_out; /* total number of bytes output so far */
137
138 z_const char *msg; /* last error message, NULL if no error */
139 struct internal_state FAR *state; /* not visible by applications */
140
141 alloc_func zalloc; /* used to allocate the internal state */
142 free_func zfree; /* used to free the internal state */
143 voidpf opaque; /* private data object passed to zalloc and zfree */
144
145 int data_type; /* best guess about the data type: binary or text
146 for deflate, or the decoding state for inflate */
147 uLong adler; /* Adler-32 or CRC-32 value of the uncompressed data */
148 uLong reserved; /* reserved for future use */
149} z_stream;
150
151typedef z_stream FAR *z_streamp;
152
153/*
154 gzip header information passed to and from zlib routines. See RFC 1952
155 for more details on the meanings of these fields.
156*/
157typedef struct gz_header_s {
158 int text; /* true if compressed data believed to be text */
159 uLong time; /* modification time */
160 int xflags; /* extra flags (not used when writing a gzip file) */
161 int os; /* operating system */
162 Bytef *extra; /* pointer to extra field or Z_NULL if none */
163 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
164 uInt extra_max; /* space at extra (only when reading header) */
165 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
166 uInt name_max; /* space at name (only when reading header) */
167 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
168 uInt comm_max; /* space at comment (only when reading header) */
169 int hcrc; /* true if there was or will be a header crc */
170 int done; /* true when done reading gzip header (not used
171 when writing a gzip file) */
172} gz_header;
173
174typedef gz_header FAR *gz_headerp;
175
176/*
177 The application must update next_in and avail_in when avail_in has dropped
178 to zero. It must update next_out and avail_out when avail_out has dropped
179 to zero. The application must initialize zalloc, zfree and opaque before
180 calling the init function. All other fields are set by the compression
181 library and must not be updated by the application.
182
183 The opaque value provided by the application will be passed as the first
184 parameter for calls of zalloc and zfree. This can be useful for custom
185 memory management. The compression library attaches no meaning to the
186 opaque value.
187
188 zalloc must return Z_NULL if there is not enough memory for the object.
189 If zlib is used in a multi-threaded application, zalloc and zfree must be
190 thread safe. In that case, zlib is thread-safe. When zalloc and zfree are
191 Z_NULL on entry to the initialization function, they are set to internal
192 routines that use the standard library functions malloc() and free().
193
194 On 16-bit systems, the functions zalloc and zfree must be able to allocate
195 exactly 65536 bytes, but will not be required to allocate more than this if
196 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
197 returned by zalloc for objects of exactly 65536 bytes *must* have their
198 offset normalized to zero. The default allocation function provided by this
199 library ensures this (see zutil.c). To reduce memory requirements and avoid
200 any allocation of 64K objects, at the expense of compression ratio, compile
201 the library with -DMAX_WBITS=14 (see zconf.h).
202
203 The fields total_in and total_out can be used for statistics or progress
204 reports. After compression, total_in holds the total size of the
205 uncompressed data and may be saved for use by the decompressor (particularly
206 if the decompressor wants to decompress everything in a single step).
207*/
208
209 /* constants */
210
211#define Z_NO_FLUSH 0
212#define Z_PARTIAL_FLUSH 1
213#define Z_SYNC_FLUSH 2
214#define Z_FULL_FLUSH 3
215#define Z_FINISH 4
216#define Z_BLOCK 5
217#define Z_TREES 6
218/* Allowed flush values; see deflate() and inflate() below for details */
219
220#define Z_OK 0
221#define Z_STREAM_END 1
222#define Z_NEED_DICT 2
223#define Z_ERRNO (-1)
224#define Z_STREAM_ERROR (-2)
225#define Z_DATA_ERROR (-3)
226#define Z_MEM_ERROR (-4)
227#define Z_BUF_ERROR (-5)
228#define Z_VERSION_ERROR (-6)
229/* Return codes for the compression/decompression functions. Negative values
230 * are errors, positive values are used for special but normal events.
231 */
232
233#define Z_NO_COMPRESSION 0
234#define Z_BEST_SPEED 1
235#define Z_BEST_COMPRESSION 9
236#define Z_DEFAULT_COMPRESSION (-1)
237/* compression levels */
238
239#define Z_FILTERED 1
240#define Z_HUFFMAN_ONLY 2
241#define Z_RLE 3
242#define Z_FIXED 4
243#define Z_DEFAULT_STRATEGY 0
244/* compression strategy; see deflateInit2() below for details */
245
246#define Z_BINARY 0
247#define Z_TEXT 1
248#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
249#define Z_UNKNOWN 2
250/* Possible values of the data_type field for deflate() */
251
252#define Z_DEFLATED 8
253/* The deflate compression method (the only one supported in this version) */
254
255#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
256
257#define zlib_version zlibVersion()
258/* for compatibility with versions < 1.0.2 */
259
260
261 /* basic functions */
262
263ZEXTERN const char * ZEXPORT zlibVersion OF((void));
264/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
265 If the first character differs, the library code actually used is not
266 compatible with the zlib.h header file used by the application. This check
267 is automatically made by deflateInit and inflateInit.
268 */
269
270/*
271ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
272
273 Initializes the internal stream state for compression. The fields
274 zalloc, zfree and opaque must be initialized before by the caller. If
275 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
276 allocation functions.
277
278 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
279 1 gives best speed, 9 gives best compression, 0 gives no compression at all
280 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
281 requests a default compromise between speed and compression (currently
282 equivalent to level 6).
283
284 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
285 memory, Z_STREAM_ERROR if level is not a valid compression level, or
286 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
287 with the version assumed by the caller (ZLIB_VERSION). msg is set to null
288 if there is no error message. deflateInit does not perform any compression:
289 this will be done by deflate().
290*/
291
292
293ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
294/*
295 deflate compresses as much data as possible, and stops when the input
296 buffer becomes empty or the output buffer becomes full. It may introduce
297 some output latency (reading input without producing any output) except when
298 forced to flush.
299
300 The detailed semantics are as follows. deflate performs one or both of the
301 following actions:
302
303 - Compress more input starting at next_in and update next_in and avail_in
304 accordingly. If not all input can be processed (because there is not
305 enough room in the output buffer), next_in and avail_in are updated and
306 processing will resume at this point for the next call of deflate().
307
308 - Generate more output starting at next_out and update next_out and avail_out
309 accordingly. This action is forced if the parameter flush is non zero.
310 Forcing flush frequently degrades the compression ratio, so this parameter
311 should be set only when necessary. Some output may be provided even if
312 flush is zero.
313
314 Before the call of deflate(), the application should ensure that at least
315 one of the actions is possible, by providing more input and/or consuming more
316 output, and updating avail_in or avail_out accordingly; avail_out should
317 never be zero before the call. The application can consume the compressed
318 output when it wants, for example when the output buffer is full (avail_out
319 == 0), or after each call of deflate(). If deflate returns Z_OK and with
320 zero avail_out, it must be called again after making room in the output
321 buffer because there might be more output pending. See deflatePending(),
322 which can be used if desired to determine whether or not there is more ouput
323 in that case.
324
325 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
326 decide how much data to accumulate before producing output, in order to
327 maximize compression.
328
329 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
330 flushed to the output buffer and the output is aligned on a byte boundary, so
331 that the decompressor can get all input data available so far. (In
332 particular avail_in is zero after the call if enough output space has been
333 provided before the call.) Flushing may degrade compression for some
334 compression algorithms and so it should be used only when necessary. This
335 completes the current deflate block and follows it with an empty stored block
336 that is three bits plus filler bits to the next byte, followed by four bytes
337 (00 00 ff ff).
338
339 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
340 output buffer, but the output is not aligned to a byte boundary. All of the
341 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
342 This completes the current deflate block and follows it with an empty fixed
343 codes block that is 10 bits long. This assures that enough bytes are output
344 in order for the decompressor to finish the block before the empty fixed
345 codes block.
346
347 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
348 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
349 seven bits of the current block are held to be written as the next byte after
350 the next deflate block is completed. In this case, the decompressor may not
351 be provided enough bits at this point in order to complete decompression of
352 the data provided so far to the compressor. It may need to wait for the next
353 block to be emitted. This is for advanced applications that need to control
354 the emission of deflate blocks.
355
356 If flush is set to Z_FULL_FLUSH, all output is flushed as with
357 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
358 restart from this point if previous compressed data has been damaged or if
359 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
360 compression.
361
362 If deflate returns with avail_out == 0, this function must be called again
363 with the same value of the flush parameter and more output space (updated
364 avail_out), until the flush is complete (deflate returns with non-zero
365 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
366 avail_out is greater than six to avoid repeated flush markers due to
367 avail_out == 0 on return.
368
369 If the parameter flush is set to Z_FINISH, pending input is processed,
370 pending output is flushed and deflate returns with Z_STREAM_END if there was
371 enough output space. If deflate returns with Z_OK or Z_BUF_ERROR, this
372 function must be called again with Z_FINISH and more output space (updated
373 avail_out) but no more input data, until it returns with Z_STREAM_END or an
374 error. After deflate has returned Z_STREAM_END, the only possible operations
375 on the stream are deflateReset or deflateEnd.
376
377 Z_FINISH can be used in the first deflate call after deflateInit if all the
378 compression is to be done in a single step. In order to complete in one
379 call, avail_out must be at least the value returned by deflateBound (see
380 below). Then deflate is guaranteed to return Z_STREAM_END. If not enough
381 output space is provided, deflate will not return Z_STREAM_END, and it must
382 be called again as described above.
383
384 deflate() sets strm->adler to the Adler-32 checksum of all input read
385 so far (that is, total_in bytes). If a gzip stream is being generated, then
386 strm->adler will be the CRC-32 checksum of the input read so far. (See
387 deflateInit2 below.)
388
389 deflate() may update strm->data_type if it can make a good guess about
390 the input data type (Z_BINARY or Z_TEXT). If in doubt, the data is
391 considered binary. This field is only for information purposes and does not
392 affect the compression algorithm in any manner.
393
394 deflate() returns Z_OK if some progress has been made (more input
395 processed or more output produced), Z_STREAM_END if all input has been
396 consumed and all output has been produced (only when flush is set to
397 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
398 if next_in or next_out was Z_NULL or the state was inadvertently written over
399 by the application), or Z_BUF_ERROR if no progress is possible (for example
400 avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and
401 deflate() can be called again with more input and more output space to
402 continue compressing.
403*/
404
405
406ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
407/*
408 All dynamically allocated data structures for this stream are freed.
409 This function discards any unprocessed input and does not flush any pending
410 output.
411
412 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
413 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
414 prematurely (some input or output was discarded). In the error case, msg
415 may be set but then points to a static string (which must not be
416 deallocated).
417*/
418
419
420/*
421ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
422
423 Initializes the internal stream state for decompression. The fields
424 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
425 the caller. In the current version of inflate, the provided input is not
426 read or consumed. The allocation of a sliding window will be deferred to
427 the first call of inflate (if the decompression does not complete on the
428 first call). If zalloc and zfree are set to Z_NULL, inflateInit updates
429 them to use default allocation functions.
430
431 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
432 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
433 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
434 invalid, such as a null pointer to the structure. msg is set to null if
435 there is no error message. inflateInit does not perform any decompression.
436 Actual decompression will be done by inflate(). So next_in, and avail_in,
437 next_out, and avail_out are unused and unchanged. The current
438 implementation of inflateInit() does not process any header information --
439 that is deferred until inflate() is called.
440*/
441
442
443ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
444/*
445 inflate decompresses as much data as possible, and stops when the input
446 buffer becomes empty or the output buffer becomes full. It may introduce
447 some output latency (reading input without producing any output) except when
448 forced to flush.
449
450 The detailed semantics are as follows. inflate performs one or both of the
451 following actions:
452
453 - Decompress more input starting at next_in and update next_in and avail_in
454 accordingly. If not all input can be processed (because there is not
455 enough room in the output buffer), then next_in and avail_in are updated
456 accordingly, and processing will resume at this point for the next call of
457 inflate().
458
459 - Generate more output starting at next_out and update next_out and avail_out
460 accordingly. inflate() provides as much output as possible, until there is
461 no more input data or no more space in the output buffer (see below about
462 the flush parameter).
463
464 Before the call of inflate(), the application should ensure that at least
465 one of the actions is possible, by providing more input and/or consuming more
466 output, and updating the next_* and avail_* values accordingly. If the
467 caller of inflate() does not provide both available input and available
468 output space, it is possible that there will be no progress made. The
469 application can consume the uncompressed output when it wants, for example
470 when the output buffer is full (avail_out == 0), or after each call of
471 inflate(). If inflate returns Z_OK and with zero avail_out, it must be
472 called again after making room in the output buffer because there might be
473 more output pending.
474
475 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
476 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
477 output as possible to the output buffer. Z_BLOCK requests that inflate()
478 stop if and when it gets to the next deflate block boundary. When decoding
479 the zlib or gzip format, this will cause inflate() to return immediately
480 after the header and before the first block. When doing a raw inflate,
481 inflate() will go ahead and process the first block, and will return when it
482 gets to the end of that block, or when it runs out of data.
483
484 The Z_BLOCK option assists in appending to or combining deflate streams.
485 To assist in this, on return inflate() always sets strm->data_type to the
486 number of unused bits in the last byte taken from strm->next_in, plus 64 if
487 inflate() is currently decoding the last block in the deflate stream, plus
488 128 if inflate() returned immediately after decoding an end-of-block code or
489 decoding the complete header up to just before the first byte of the deflate
490 stream. The end-of-block will not be indicated until all of the uncompressed
491 data from that block has been written to strm->next_out. The number of
492 unused bits may in general be greater than seven, except when bit 7 of
493 data_type is set, in which case the number of unused bits will be less than
494 eight. data_type is set as noted here every time inflate() returns for all
495 flush options, and so can be used to determine the amount of currently
496 consumed input in bits.
497
498 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
499 end of each deflate block header is reached, before any actual data in that
500 block is decoded. This allows the caller to determine the length of the
501 deflate block header for later use in random access within a deflate block.
502 256 is added to the value of strm->data_type when inflate() returns
503 immediately after reaching the end of the deflate block header.
504
505 inflate() should normally be called until it returns Z_STREAM_END or an
506 error. However if all decompression is to be performed in a single step (a
507 single call of inflate), the parameter flush should be set to Z_FINISH. In
508 this case all pending input is processed and all pending output is flushed;
509 avail_out must be large enough to hold all of the uncompressed data for the
510 operation to complete. (The size of the uncompressed data may have been
511 saved by the compressor for this purpose.) The use of Z_FINISH is not
512 required to perform an inflation in one step. However it may be used to
513 inform inflate that a faster approach can be used for the single inflate()
514 call. Z_FINISH also informs inflate to not maintain a sliding window if the
515 stream completes, which reduces inflate's memory footprint. If the stream
516 does not complete, either because not all of the stream is provided or not
517 enough output space is provided, then a sliding window will be allocated and
518 inflate() can be called again to continue the operation as if Z_NO_FLUSH had
519 been used.
520
521 In this implementation, inflate() always flushes as much output as
522 possible to the output buffer, and always uses the faster approach on the
523 first call. So the effects of the flush parameter in this implementation are
524 on the return value of inflate() as noted below, when inflate() returns early
525 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
526 memory for a sliding window when Z_FINISH is used.
527
528 If a preset dictionary is needed after this call (see inflateSetDictionary
529 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
530 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
531 strm->adler to the Adler-32 checksum of all output produced so far (that is,
532 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
533 below. At the end of the stream, inflate() checks that its computed Adler-32
534 checksum is equal to that saved by the compressor and returns Z_STREAM_END
535 only if the checksum is correct.
536
537 inflate() can decompress and check either zlib-wrapped or gzip-wrapped
538 deflate data. The header type is detected automatically, if requested when
539 initializing with inflateInit2(). Any information contained in the gzip
540 header is not retained unless inflateGetHeader() is used. When processing
541 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
542 produced so far. The CRC-32 is checked against the gzip trailer, as is the
543 uncompressed length, modulo 2^32.
544
545 inflate() returns Z_OK if some progress has been made (more input processed
546 or more output produced), Z_STREAM_END if the end of the compressed data has
547 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
548 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
549 corrupted (input stream not conforming to the zlib format or incorrect check
550 value, in which case strm->msg points to a string with a more specific
551 error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
552 next_in or next_out was Z_NULL, or the state was inadvertently written over
553 by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
554 if no progress was possible or if there was not enough room in the output
555 buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
556 inflate() can be called again with more input and more output space to
557 continue decompressing. If Z_DATA_ERROR is returned, the application may
558 then call inflateSync() to look for a good compression block if a partial
559 recovery of the data is to be attempted.
560*/
561
562
563ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
564/*
565 All dynamically allocated data structures for this stream are freed.
566 This function discards any unprocessed input and does not flush any pending
567 output.
568
569 inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state
570 was inconsistent.
571*/
572
573
574 /* Advanced functions */
575
576/*
577 The following functions are needed only in some special applications.
578*/
579
580/*
581ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
582 int level,
583 int method,
584 int windowBits,
585 int memLevel,
586 int strategy));
587
588 This is another version of deflateInit with more compression options. The
589 fields zalloc, zfree and opaque must be initialized before by the caller.
590
591 The method parameter is the compression method. It must be Z_DEFLATED in
592 this version of the library.
593
594 The windowBits parameter is the base two logarithm of the window size
595 (the size of the history buffer). It should be in the range 8..15 for this
596 version of the library. Larger values of this parameter result in better
597 compression at the expense of memory usage. The default value is 15 if
598 deflateInit is used instead.
599
600 For the current implementation of deflate(), a windowBits value of 8 (a
601 window size of 256 bytes) is not supported. As a result, a request for 8
602 will result in 9 (a 512-byte window). In that case, providing 8 to
603 inflateInit2() will result in an error when the zlib header with 9 is
604 checked against the initialization of inflate(). The remedy is to not use 8
605 with deflateInit2() with this initialization, or at least in that case use 9
606 with inflateInit2().
607
608 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
609 determines the window size. deflate() will then generate raw deflate data
610 with no zlib header or trailer, and will not compute a check value.
611
612 windowBits can also be greater than 15 for optional gzip encoding. Add
613 16 to windowBits to write a simple gzip header and trailer around the
614 compressed data instead of a zlib wrapper. The gzip header will have no
615 file name, no extra data, no comment, no modification time (set to zero), no
616 header crc, and the operating system will be set to the appropriate value,
617 if the operating system was determined at compile time. If a gzip stream is
618 being written, strm->adler is a CRC-32 instead of an Adler-32.
619
620 For raw deflate or gzip encoding, a request for a 256-byte window is
621 rejected as invalid, since only the zlib header provides a means of
622 transmitting the window size to the decompressor.
623
624 The memLevel parameter specifies how much memory should be allocated
625 for the internal compression state. memLevel=1 uses minimum memory but is
626 slow and reduces compression ratio; memLevel=9 uses maximum memory for
627 optimal speed. The default value is 8. See zconf.h for total memory usage
628 as a function of windowBits and memLevel.
629
630 The strategy parameter is used to tune the compression algorithm. Use the
631 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
632 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
633 string match), or Z_RLE to limit match distances to one (run-length
634 encoding). Filtered data consists mostly of small values with a somewhat
635 random distribution. In this case, the compression algorithm is tuned to
636 compress them better. The effect of Z_FILTERED is to force more Huffman
637 coding and less string matching; it is somewhat intermediate between
638 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
639 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
640 strategy parameter only affects the compression ratio but not the
641 correctness of the compressed output even if it is not set appropriately.
642 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
643 decoder for special applications.
644
645 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
646 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
647 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
648 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
649 set to null if there is no error message. deflateInit2 does not perform any
650 compression: this will be done by deflate().
651*/
652
653ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
654 const Bytef *dictionary,
655 uInt dictLength));
656/*
657 Initializes the compression dictionary from the given byte sequence
658 without producing any compressed output. When using the zlib format, this
659 function must be called immediately after deflateInit, deflateInit2 or
660 deflateReset, and before any call of deflate. When doing raw deflate, this
661 function must be called either before any call of deflate, or immediately
662 after the completion of a deflate block, i.e. after all input has been
663 consumed and all output has been delivered when using any of the flush
664 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The
665 compressor and decompressor must use exactly the same dictionary (see
666 inflateSetDictionary).
667
668 The dictionary should consist of strings (byte sequences) that are likely
669 to be encountered later in the data to be compressed, with the most commonly
670 used strings preferably put towards the end of the dictionary. Using a
671 dictionary is most useful when the data to be compressed is short and can be
672 predicted with good accuracy; the data can then be compressed better than
673 with the default empty dictionary.
674
675 Depending on the size of the compression data structures selected by
676 deflateInit or deflateInit2, a part of the dictionary may in effect be
677 discarded, for example if the dictionary is larger than the window size
678 provided in deflateInit or deflateInit2. Thus the strings most likely to be
679 useful should be put at the end of the dictionary, not at the front. In
680 addition, the current implementation of deflate will use at most the window
681 size minus 262 bytes of the provided dictionary.
682
683 Upon return of this function, strm->adler is set to the Adler-32 value
684 of the dictionary; the decompressor may later use this value to determine
685 which dictionary has been used by the compressor. (The Adler-32 value
686 applies to the whole dictionary even if only a subset of the dictionary is
687 actually used by the compressor.) If a raw deflate was requested, then the
688 Adler-32 value is not computed and strm->adler is not set.
689
690 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
691 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
692 inconsistent (for example if deflate has already been called for this stream
693 or if not at a block boundary for raw deflate). deflateSetDictionary does
694 not perform any compression: this will be done by deflate().
695*/
696
697#if !defined(__ANDROID__) || __ANDROID_API__ >= 28
698ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
699 Bytef *dictionary,
700 uInt *dictLength));
701#endif
702/*
703 Returns the sliding dictionary being maintained by deflate. dictLength is
704 set to the number of bytes in the dictionary, and that many bytes are copied
705 to dictionary. dictionary must have enough space, where 32768 bytes is
706 always enough. If deflateGetDictionary() is called with dictionary equal to
707 Z_NULL, then only the dictionary length is returned, and nothing is copied.
708 Similary, if dictLength is Z_NULL, then it is not set.
709
710 deflateGetDictionary() may return a length less than the window size, even
711 when more than the window size in input has been provided. It may return up
712 to 258 bytes less in that case, due to how zlib's implementation of deflate
713 manages the sliding window and lookahead for matches, where matches can be
714 up to 258 bytes long. If the application needs the last window-size bytes of
715 input, then that would need to be saved by the application outside of zlib.
716
717 deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
718 stream state is inconsistent.
719*/
720
721ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
722 z_streamp source));
723/*
724 Sets the destination stream as a complete copy of the source stream.
725
726 This function can be useful when several compression strategies will be
727 tried, for example when there are several ways of pre-processing the input
728 data with a filter. The streams that will be discarded should then be freed
729 by calling deflateEnd. Note that deflateCopy duplicates the internal
730 compression state which can be quite large, so this strategy is slow and can
731 consume lots of memory.
732
733 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
734 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
735 (such as zalloc being Z_NULL). msg is left unchanged in both source and
736 destination.
737*/
738
739ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
740/*
741 This function is equivalent to deflateEnd followed by deflateInit, but
742 does not free and reallocate the internal compression state. The stream
743 will leave the compression level and any other attributes that may have been
744 set unchanged.
745
746 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
747 stream state was inconsistent (such as zalloc or state being Z_NULL).
748*/
749
750ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
751 int level,
752 int strategy));
753/*
754 Dynamically update the compression level and compression strategy. The
755 interpretation of level and strategy is as in deflateInit2(). This can be
756 used to switch between compression and straight copy of the input data, or
757 to switch to a different kind of input data requiring a different strategy.
758 If the compression approach (which is a function of the level) or the
759 strategy is changed, and if there have been any deflate() calls since the
760 state was initialized or reset, then the input available so far is
761 compressed with the old level and strategy using deflate(strm, Z_BLOCK).
762 There are three approaches for the compression levels 0, 1..3, and 4..9
763 respectively. The new level and strategy will take effect at the next call
764 of deflate().
765
766 If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
767 not have enough output space to complete, then the parameter change will not
768 take effect. In this case, deflateParams() can be called again with the
769 same parameters and more output space to try again.
770
771 In order to assure a change in the parameters on the first try, the
772 deflate stream should be flushed using deflate() with Z_BLOCK or other flush
773 request until strm.avail_out is not zero, before calling deflateParams().
774 Then no more input data should be provided before the deflateParams() call.
775 If this is done, the old level and strategy will be applied to the data
776 compressed before deflateParams(), and the new level and strategy will be
777 applied to the the data compressed after deflateParams().
778
779 deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
780 state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
781 there was not enough output space to complete the compression of the
782 available input data before a change in the strategy or approach. Note that
783 in the case of a Z_BUF_ERROR, the parameters are not changed. A return
784 value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
785 retried with more output space.
786*/
787
788ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
789 int good_length,
790 int max_lazy,
791 int nice_length,
792 int max_chain));
793/*
794 Fine tune deflate's internal compression parameters. This should only be
795 used by someone who understands the algorithm used by zlib's deflate for
796 searching for the best matching string, and even then only by the most
797 fanatic optimizer trying to squeeze out the last compressed bit for their
798 specific input data. Read the deflate.c source code for the meaning of the
799 max_lazy, good_length, nice_length, and max_chain parameters.
800
801 deflateTune() can be called after deflateInit() or deflateInit2(), and
802 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
803 */
804
805ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
806 uLong sourceLen));
807/*
808 deflateBound() returns an upper bound on the compressed size after
809 deflation of sourceLen bytes. It must be called after deflateInit() or
810 deflateInit2(), and after deflateSetHeader(), if used. This would be used
811 to allocate an output buffer for deflation in a single pass, and so would be
812 called before deflate(). If that first deflate() call is provided the
813 sourceLen input bytes, an output buffer allocated to the size returned by
814 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
815 to return Z_STREAM_END. Note that it is possible for the compressed size to
816 be larger than the value returned by deflateBound() if flush options other
817 than Z_FINISH or Z_NO_FLUSH are used.
818*/
819
820ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
821 unsigned *pending,
822 int *bits));
823/*
824 deflatePending() returns the number of bytes and bits of output that have
825 been generated, but not yet provided in the available output. The bytes not
826 provided would be due to the available output space having being consumed.
827 The number of bits of output not provided are between 0 and 7, where they
828 await more bits to join them in order to fill out a full byte. If pending
829 or bits are Z_NULL, then those values are not set.
830
831 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
832 stream state was inconsistent.
833 */
834
835ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
836 int bits,
837 int value));
838/*
839 deflatePrime() inserts bits in the deflate output stream. The intent
840 is that this function is used to start off the deflate output with the bits
841 leftover from a previous deflate stream when appending to it. As such, this
842 function can only be used for raw deflate, and must be used before the first
843 deflate() call after a deflateInit2() or deflateReset(). bits must be less
844 than or equal to 16, and that many of the least significant bits of value
845 will be inserted in the output.
846
847 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
848 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
849 source stream state was inconsistent.
850*/
851
852ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
853 gz_headerp head));
854/*
855 deflateSetHeader() provides gzip header information for when a gzip
856 stream is requested by deflateInit2(). deflateSetHeader() may be called
857 after deflateInit2() or deflateReset() and before the first call of
858 deflate(). The text, time, os, extra field, name, and comment information
859 in the provided gz_header structure are written to the gzip header (xflag is
860 ignored -- the extra flags are set according to the compression level). The
861 caller must assure that, if not Z_NULL, name and comment are terminated with
862 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
863 available there. If hcrc is true, a gzip header crc is included. Note that
864 the current versions of the command-line version of gzip (up through version
865 1.3.x) do not support header crc's, and will report that it is a "multi-part
866 gzip file" and give up.
867
868 If deflateSetHeader is not used, the default gzip header has text false,
869 the time set to zero, and os set to 255, with no extra, name, or comment
870 fields. The gzip header is returned to the default state by deflateReset().
871
872 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
873 stream state was inconsistent.
874*/
875
876/*
877ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
878 int windowBits));
879
880 This is another version of inflateInit with an extra parameter. The
881 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
882 before by the caller.
883
884 The windowBits parameter is the base two logarithm of the maximum window
885 size (the size of the history buffer). It should be in the range 8..15 for
886 this version of the library. The default value is 15 if inflateInit is used
887 instead. windowBits must be greater than or equal to the windowBits value
888 provided to deflateInit2() while compressing, or it must be equal to 15 if
889 deflateInit2() was not used. If a compressed stream with a larger window
890 size is given as input, inflate() will return with the error code
891 Z_DATA_ERROR instead of trying to allocate a larger window.
892
893 windowBits can also be zero to request that inflate use the window size in
894 the zlib header of the compressed stream.
895
896 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
897 determines the window size. inflate() will then process raw deflate data,
898 not looking for a zlib or gzip header, not generating a check value, and not
899 looking for any check values for comparison at the end of the stream. This
900 is for use with other formats that use the deflate compressed data format
901 such as zip. Those formats provide their own check values. If a custom
902 format is developed using the raw deflate format for compressed data, it is
903 recommended that a check value such as an Adler-32 or a CRC-32 be applied to
904 the uncompressed data as is done in the zlib, gzip, and zip formats. For
905 most applications, the zlib format should be used as is. Note that comments
906 above on the use in deflateInit2() applies to the magnitude of windowBits.
907
908 windowBits can also be greater than 15 for optional gzip decoding. Add
909 32 to windowBits to enable zlib and gzip decoding with automatic header
910 detection, or add 16 to decode only the gzip format (the zlib format will
911 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
912 CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see
913 below), inflate() will *not* automatically decode concatenated gzip members.
914 inflate() will return Z_STREAM_END at the end of the gzip member. The state
915 would need to be reset to continue decoding a subsequent gzip member. This
916 *must* be done if there is more data after a gzip member, in order for the
917 decompression to be compliant with the gzip standard (RFC 1952).
918
919 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
920 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
921 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
922 invalid, such as a null pointer to the structure. msg is set to null if
923 there is no error message. inflateInit2 does not perform any decompression
924 apart from possibly reading the zlib header if present: actual decompression
925 will be done by inflate(). (So next_in and avail_in may be modified, but
926 next_out and avail_out are unused and unchanged.) The current implementation
927 of inflateInit2() does not process any header information -- that is
928 deferred until inflate() is called.
929*/
930
931ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
932 const Bytef *dictionary,
933 uInt dictLength));
934/*
935 Initializes the decompression dictionary from the given uncompressed byte
936 sequence. This function must be called immediately after a call of inflate,
937 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
938 can be determined from the Adler-32 value returned by that call of inflate.
939 The compressor and decompressor must use exactly the same dictionary (see
940 deflateSetDictionary). For raw inflate, this function can be called at any
941 time to set the dictionary. If the provided dictionary is smaller than the
942 window and there is already data in the window, then the provided dictionary
943 will amend what's there. The application must insure that the dictionary
944 that was used for compression is provided.
945
946 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
947 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
948 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
949 expected one (incorrect Adler-32 value). inflateSetDictionary does not
950 perform any decompression: this will be done by subsequent calls of
951 inflate().
952*/
953
954#if !defined(__ANDROID__) || __ANDROID_API__ >= 19
955ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
956 Bytef *dictionary,
957 uInt *dictLength));
958#endif
959/*
960 Returns the sliding dictionary being maintained by inflate. dictLength is
961 set to the number of bytes in the dictionary, and that many bytes are copied
962 to dictionary. dictionary must have enough space, where 32768 bytes is
963 always enough. If inflateGetDictionary() is called with dictionary equal to
964 Z_NULL, then only the dictionary length is returned, and nothing is copied.
965 Similary, if dictLength is Z_NULL, then it is not set.
966
967 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
968 stream state is inconsistent.
969*/
970
971ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
972/*
973 Skips invalid compressed data until a possible full flush point (see above
974 for the description of deflate with Z_FULL_FLUSH) can be found, or until all
975 available input is skipped. No output is provided.
976
977 inflateSync searches for a 00 00 FF FF pattern in the compressed data.
978 All full flush points have this pattern, but not all occurrences of this
979 pattern are full flush points.
980
981 inflateSync returns Z_OK if a possible full flush point has been found,
982 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
983 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
984 In the success case, the application may save the current current value of
985 total_in which indicates where valid compressed data was found. In the
986 error case, the application may repeatedly call inflateSync, providing more
987 input each time, until success or end of the input data.
988*/
989
990ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
991 z_streamp source));
992/*
993 Sets the destination stream as a complete copy of the source stream.
994
995 This function can be useful when randomly accessing a large stream. The
996 first pass through the stream can periodically record the inflate state,
997 allowing restarting inflate at those points when randomly accessing the
998 stream.
999
1000 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
1001 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
1002 (such as zalloc being Z_NULL). msg is left unchanged in both source and
1003 destination.
1004*/
1005
1006ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
1007/*
1008 This function is equivalent to inflateEnd followed by inflateInit,
1009 but does not free and reallocate the internal decompression state. The
1010 stream will keep attributes that may have been set by inflateInit2.
1011
1012 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
1013 stream state was inconsistent (such as zalloc or state being Z_NULL).
1014*/
1015
1016ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
1017 int windowBits));
1018/*
1019 This function is the same as inflateReset, but it also permits changing
1020 the wrap and window size requests. The windowBits parameter is interpreted
1021 the same as it is for inflateInit2. If the window size is changed, then the
1022 memory allocated for the window is freed, and the window will be reallocated
1023 by inflate() if needed.
1024
1025 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
1026 stream state was inconsistent (such as zalloc or state being Z_NULL), or if
1027 the windowBits parameter is invalid.
1028*/
1029
1030ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
1031 int bits,
1032 int value));
1033/*
1034 This function inserts bits in the inflate input stream. The intent is
1035 that this function is used to start inflating at a bit position in the
1036 middle of a byte. The provided bits will be used before any bytes are used
1037 from next_in. This function should only be used with raw inflate, and
1038 should be used before the first inflate() call after inflateInit2() or
1039 inflateReset(). bits must be less than or equal to 16, and that many of the
1040 least significant bits of value will be inserted in the input.
1041
1042 If bits is negative, then the input stream bit buffer is emptied. Then
1043 inflatePrime() can be called again to put bits in the buffer. This is used
1044 to clear out bits leftover after feeding inflate a block description prior
1045 to feeding inflate codes.
1046
1047 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
1048 stream state was inconsistent.
1049*/
1050
1051ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
1052/*
1053 This function returns two values, one in the lower 16 bits of the return
1054 value, and the other in the remaining upper bits, obtained by shifting the
1055 return value down 16 bits. If the upper value is -1 and the lower value is
1056 zero, then inflate() is currently decoding information outside of a block.
1057 If the upper value is -1 and the lower value is non-zero, then inflate is in
1058 the middle of a stored block, with the lower value equaling the number of
1059 bytes from the input remaining to copy. If the upper value is not -1, then
1060 it is the number of bits back from the current bit position in the input of
1061 the code (literal or length/distance pair) currently being processed. In
1062 that case the lower value is the number of bytes already emitted for that
1063 code.
1064
1065 A code is being processed if inflate is waiting for more input to complete
1066 decoding of the code, or if it has completed decoding but is waiting for
1067 more output space to write the literal or match data.
1068
1069 inflateMark() is used to mark locations in the input data for random
1070 access, which may be at bit positions, and to note those cases where the
1071 output of a code may span boundaries of random access blocks. The current
1072 location in the input stream can be determined from avail_in and data_type
1073 as noted in the description for the Z_BLOCK flush parameter for inflate.
1074
1075 inflateMark returns the value noted above, or -65536 if the provided
1076 source stream state was inconsistent.
1077*/
1078
1079ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
1080 gz_headerp head));
1081/*
1082 inflateGetHeader() requests that gzip header information be stored in the
1083 provided gz_header structure. inflateGetHeader() may be called after
1084 inflateInit2() or inflateReset(), and before the first call of inflate().
1085 As inflate() processes the gzip stream, head->done is zero until the header
1086 is completed, at which time head->done is set to one. If a zlib stream is
1087 being decoded, then head->done is set to -1 to indicate that there will be
1088 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
1089 used to force inflate() to return immediately after header processing is
1090 complete and before any actual data is decompressed.
1091
1092 The text, time, xflags, and os fields are filled in with the gzip header
1093 contents. hcrc is set to true if there is a header CRC. (The header CRC
1094 was valid if done is set to one.) If extra is not Z_NULL, then extra_max
1095 contains the maximum number of bytes to write to extra. Once done is true,
1096 extra_len contains the actual extra field length, and extra contains the
1097 extra field, or that field truncated if extra_max is less than extra_len.
1098 If name is not Z_NULL, then up to name_max characters are written there,
1099 terminated with a zero unless the length is greater than name_max. If
1100 comment is not Z_NULL, then up to comm_max characters are written there,
1101 terminated with a zero unless the length is greater than comm_max. When any
1102 of extra, name, or comment are not Z_NULL and the respective field is not
1103 present in the header, then that field is set to Z_NULL to signal its
1104 absence. This allows the use of deflateSetHeader() with the returned
1105 structure to duplicate the header. However if those fields are set to
1106 allocated memory, then the application will need to save those pointers
1107 elsewhere so that they can be eventually freed.
1108
1109 If inflateGetHeader is not used, then the header information is simply
1110 discarded. The header is always checked for validity, including the header
1111 CRC if present. inflateReset() will reset the process to discard the header
1112 information. The application would need to call inflateGetHeader() again to
1113 retrieve the header from the next gzip stream.
1114
1115 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
1116 stream state was inconsistent.
1117*/
1118
1119/*
1120ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
1121 unsigned char FAR *window));
1122
1123 Initialize the internal stream state for decompression using inflateBack()
1124 calls. The fields zalloc, zfree and opaque in strm must be initialized
1125 before the call. If zalloc and zfree are Z_NULL, then the default library-
1126 derived memory allocation routines are used. windowBits is the base two
1127 logarithm of the window size, in the range 8..15. window is a caller
1128 supplied buffer of that size. Except for special applications where it is
1129 assured that deflate was used with small window sizes, windowBits must be 15
1130 and a 32K byte window must be supplied to be able to decompress general
1131 deflate streams.
1132
1133 See inflateBack() for the usage of these routines.
1134
1135 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
1136 the parameters are invalid, Z_MEM_ERROR if the internal state could not be
1137 allocated, or Z_VERSION_ERROR if the version of the library does not match
1138 the version of the header file.
1139*/
1140
1141typedef unsigned (*in_func) OF((void FAR *,
1142 z_const unsigned char FAR * FAR *));
1143typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
1144
1145ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
1146 in_func in, void FAR *in_desc,
1147 out_func out, void FAR *out_desc));
1148/*
1149 inflateBack() does a raw inflate with a single call using a call-back
1150 interface for input and output. This is potentially more efficient than
1151 inflate() for file i/o applications, in that it avoids copying between the
1152 output and the sliding window by simply making the window itself the output
1153 buffer. inflate() can be faster on modern CPUs when used with large
1154 buffers. inflateBack() trusts the application to not change the output
1155 buffer passed by the output function, at least until inflateBack() returns.
1156
1157 inflateBackInit() must be called first to allocate the internal state
1158 and to initialize the state with the user-provided window buffer.
1159 inflateBack() may then be used multiple times to inflate a complete, raw
1160 deflate stream with each call. inflateBackEnd() is then called to free the
1161 allocated state.
1162
1163 A raw deflate stream is one with no zlib or gzip header or trailer.
1164 This routine would normally be used in a utility that reads zip or gzip
1165 files and writes out uncompressed files. The utility would decode the
1166 header and process the trailer on its own, hence this routine expects only
1167 the raw deflate stream to decompress. This is different from the default
1168 behavior of inflate(), which expects a zlib header and trailer around the
1169 deflate stream.
1170
1171 inflateBack() uses two subroutines supplied by the caller that are then
1172 called by inflateBack() for input and output. inflateBack() calls those
1173 routines until it reads a complete deflate stream and writes out all of the
1174 uncompressed data, or until it encounters an error. The function's
1175 parameters and return types are defined above in the in_func and out_func
1176 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
1177 number of bytes of provided input, and a pointer to that input in buf. If
1178 there is no input available, in() must return zero -- buf is ignored in that
1179 case -- and inflateBack() will return a buffer error. inflateBack() will
1180 call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
1181 out() should return zero on success, or non-zero on failure. If out()
1182 returns non-zero, inflateBack() will return with an error. Neither in() nor
1183 out() are permitted to change the contents of the window provided to
1184 inflateBackInit(), which is also the buffer that out() uses to write from.
1185 The length written by out() will be at most the window size. Any non-zero
1186 amount of input may be provided by in().
1187
1188 For convenience, inflateBack() can be provided input on the first call by
1189 setting strm->next_in and strm->avail_in. If that input is exhausted, then
1190 in() will be called. Therefore strm->next_in must be initialized before
1191 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
1192 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
1193 must also be initialized, and then if strm->avail_in is not zero, input will
1194 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
1195
1196 The in_desc and out_desc parameters of inflateBack() is passed as the
1197 first parameter of in() and out() respectively when they are called. These
1198 descriptors can be optionally used to pass any information that the caller-
1199 supplied in() and out() functions need to do their job.
1200
1201 On return, inflateBack() will set strm->next_in and strm->avail_in to
1202 pass back any unused input that was provided by the last in() call. The
1203 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
1204 if in() or out() returned an error, Z_DATA_ERROR if there was a format error
1205 in the deflate stream (in which case strm->msg is set to indicate the nature
1206 of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
1207 In the case of Z_BUF_ERROR, an input or output error can be distinguished
1208 using strm->next_in which will be Z_NULL only if in() returned an error. If
1209 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1210 non-zero. (in() will always be called before out(), so strm->next_in is
1211 assured to be defined if out() returns non-zero.) Note that inflateBack()
1212 cannot return Z_OK.
1213*/
1214
1215ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
1216/*
1217 All memory allocated by inflateBackInit() is freed.
1218
1219 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
1220 state was inconsistent.
1221*/
1222
1223ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
1224/* Return flags indicating compile-time options.
1225
1226 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1227 1.0: size of uInt
1228 3.2: size of uLong
1229 5.4: size of voidpf (pointer)
1230 7.6: size of z_off_t
1231
1232 Compiler, assembler, and debug options:
1233 8: ZLIB_DEBUG
1234 9: ASMV or ASMINF -- use ASM code
1235 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1236 11: 0 (reserved)
1237
1238 One-time table building (smaller code, but not thread-safe if true):
1239 12: BUILDFIXED -- build static block decoding tables when needed
1240 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1241 14,15: 0 (reserved)
1242
1243 Library content (indicates missing functionality):
1244 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1245 deflate code when not needed)
1246 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1247 and decode gzip streams (to avoid linking crc code)
1248 18-19: 0 (reserved)
1249
1250 Operation variations (changes in library functionality):
1251 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1252 21: FASTEST -- deflate algorithm with only one, lowest compression level
1253 22,23: 0 (reserved)
1254
1255 The sprintf variant used by gzprintf (zero is best):
1256 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1257 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1258 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1259
1260 Remainder:
1261 27-31: 0 (reserved)
1262 */
1263
1264#ifndef Z_SOLO
1265
1266 /* utility functions */
1267
1268/*
1269 The following utility functions are implemented on top of the basic
1270 stream-oriented functions. To simplify the interface, some default options
1271 are assumed (compression level and memory usage, standard memory allocation
1272 functions). The source code of these utility functions can be modified if
1273 you need special options.
1274*/
1275
1276ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
1277 const Bytef *source, uLong sourceLen));
1278/*
1279 Compresses the source buffer into the destination buffer. sourceLen is
1280 the byte length of the source buffer. Upon entry, destLen is the total size
1281 of the destination buffer, which must be at least the value returned by
1282 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1283 compressed data. compress() is equivalent to compress2() with a level
1284 parameter of Z_DEFAULT_COMPRESSION.
1285
1286 compress returns Z_OK if success, Z_MEM_ERROR if there was not
1287 enough memory, Z_BUF_ERROR if there was not enough room in the output
1288 buffer.
1289*/
1290
1291ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
1292 const Bytef *source, uLong sourceLen,
1293 int level));
1294/*
1295 Compresses the source buffer into the destination buffer. The level
1296 parameter has the same meaning as in deflateInit. sourceLen is the byte
1297 length of the source buffer. Upon entry, destLen is the total size of the
1298 destination buffer, which must be at least the value returned by
1299 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1300 compressed data.
1301
1302 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1303 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1304 Z_STREAM_ERROR if the level parameter is invalid.
1305*/
1306
1307ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1308/*
1309 compressBound() returns an upper bound on the compressed size after
1310 compress() or compress2() on sourceLen bytes. It would be used before a
1311 compress() or compress2() call to allocate the destination buffer.
1312*/
1313
1314ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
1315 const Bytef *source, uLong sourceLen));
1316/*
1317 Decompresses the source buffer into the destination buffer. sourceLen is
1318 the byte length of the source buffer. Upon entry, destLen is the total size
1319 of the destination buffer, which must be large enough to hold the entire
1320 uncompressed data. (The size of the uncompressed data must have been saved
1321 previously by the compressor and transmitted to the decompressor by some
1322 mechanism outside the scope of this compression library.) Upon exit, destLen
1323 is the actual size of the uncompressed data.
1324
1325 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1326 enough memory, Z_BUF_ERROR if there was not enough room in the output
1327 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In
1328 the case where there is not enough room, uncompress() will fill the output
1329 buffer with the uncompressed data up to that point.
1330*/
1331
1332#if !defined(__ANDROID__) || __ANDROID_API__ >= 28
1333ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest, uLongf *destLen,
1334 const Bytef *source, uLong *sourceLen));
1335#endif
1336/*
1337 Same as uncompress, except that sourceLen is a pointer, where the
1338 length of the source is *sourceLen. On return, *sourceLen is the number of
1339 source bytes consumed.
1340*/
1341
1342 /* gzip file access functions */
1343
1344/*
1345 This library supports reading and writing files in gzip (.gz) format with
1346 an interface similar to that of stdio, using the functions that start with
1347 "gz". The gzip format is different from the zlib format. gzip is a gzip
1348 wrapper, documented in RFC 1952, wrapped around a deflate stream.
1349*/
1350
1351typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
1352
1353/*
1354ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1355
1356 Open the gzip (.gz) file at path for reading and decompressing, or
1357 compressing and writing. The mode parameter is as in fopen ("rb" or "wb")
1358 but can also include a compression level ("wb9") or a strategy: 'f' for
1359 filtered data as in "wb6f", 'h' for Huffman-only compression as in "wb1h",
1360 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression
1361 as in "wb9F". (See the description of deflateInit2 for more information
1362 about the strategy parameter.) 'T' will request transparent writing or
1363 appending with no compression and not using the gzip format.
1364
1365 "a" can be used instead of "w" to request that the gzip stream that will
1366 be written be appended to the file. "+" will result in an error, since
1367 reading and writing to the same gzip file is not supported. The addition of
1368 "x" when writing will create the file exclusively, which fails if the file
1369 already exists. On systems that support it, the addition of "e" when
1370 reading or writing will set the flag to close the file on an execve() call.
1371
1372 These functions, as well as gzip, will read and decode a sequence of gzip
1373 streams in a file. The append function of gzopen() can be used to create
1374 such a file. (Also see gzflush() for another way to do this.) When
1375 appending, gzopen does not test whether the file begins with a gzip stream,
1376 nor does it look for the end of the gzip streams to begin appending. gzopen
1377 will simply append a gzip stream to the existing file.
1378
1379 gzopen can be used to read a file which is not in gzip format; in this
1380 case gzread will directly read from the file without decompression. When
1381 reading, this will be detected automatically by looking for the magic two-
1382 byte gzip header.
1383
1384 gzopen returns NULL if the file could not be opened, if there was
1385 insufficient memory to allocate the gzFile state, or if an invalid mode was
1386 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
1387 errno can be checked to determine if the reason gzopen failed was that the
1388 file could not be opened.
1389*/
1390
1391ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1392/*
1393 Associate a gzFile with the file descriptor fd. File descriptors are
1394 obtained from calls like open, dup, creat, pipe or fileno (if the file has
1395 been previously opened with fopen). The mode parameter is as in gzopen.
1396
1397 The next call of gzclose on the returned gzFile will also close the file
1398 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
1399 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
1400 mode);. The duplicated descriptor should be saved to avoid a leak, since
1401 gzdopen does not close fd if it fails. If you are using fileno() to get the
1402 file descriptor from a FILE *, then you will have to use dup() to avoid
1403 double-close()ing the file descriptor. Both gzclose() and fclose() will
1404 close the associated file descriptor, so they need to have different file
1405 descriptors.
1406
1407 gzdopen returns NULL if there was insufficient memory to allocate the
1408 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
1409 provided, or '+' was provided), or if fd is -1. The file descriptor is not
1410 used until the next gz* read, write, seek, or close operation, so gzdopen
1411 will not detect if fd is invalid (unless fd is -1).
1412*/
1413
1414ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
1415/*
1416 Set the internal buffer size used by this library's functions for file to
1417 size. The default buffer size is 8192 bytes. This function must be called
1418 after gzopen() or gzdopen(), and before any other calls that read or write
1419 the file. The buffer memory allocation is always deferred to the first read
1420 or write. Three times that size in buffer space is allocated. A larger
1421 buffer size of, for example, 64K or 128K bytes will noticeably increase the
1422 speed of decompression (reading).
1423
1424 The new buffer size also affects the maximum length for gzprintf().
1425
1426 gzbuffer() returns 0 on success, or -1 on failure, such as being called
1427 too late.
1428*/
1429
1430ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1431/*
1432 Dynamically update the compression level and strategy for file. See the
1433 description of deflateInit2 for the meaning of these parameters. Previously
1434 provided data is flushed before applying the parameter changes.
1435
1436 gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
1437 opened for writing, Z_ERRNO if there is an error writing the flushed data,
1438 or Z_MEM_ERROR if there is a memory allocation error.
1439*/
1440
1441ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1442/*
1443 Read and decompress up to len uncompressed bytes from file into buf. If
1444 the input file is not in gzip format, gzread copies the given number of
1445 bytes into the buffer directly from the file.
1446
1447 After reaching the end of a gzip stream in the input, gzread will continue
1448 to read, looking for another gzip stream. Any number of gzip streams may be
1449 concatenated in the input file, and will all be decompressed by gzread().
1450 If something other than a gzip stream is encountered after a gzip stream,
1451 that remaining trailing garbage is ignored (and no error is returned).
1452
1453 gzread can be used to read a gzip file that is being concurrently written.
1454 Upon reaching the end of the input, gzread will return with the available
1455 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
1456 gzclearerr can be used to clear the end of file indicator in order to permit
1457 gzread to be tried again. Z_OK indicates that a gzip stream was completed
1458 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the
1459 middle of a gzip stream. Note that gzread does not return -1 in the event
1460 of an incomplete gzip stream. This error is deferred until gzclose(), which
1461 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
1462 stream. Alternatively, gzerror can be used before gzclose to detect this
1463 case.
1464
1465 gzread returns the number of uncompressed bytes actually read, less than
1466 len for end of file, or -1 for error. If len is too large to fit in an int,
1467 then nothing is read, -1 is returned, and the error state is set to
1468 Z_STREAM_ERROR.
1469*/
1470
1471#if !defined(__ANDROID__) || __ANDROID_API__ >= 28
1472ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
1473 gzFile file));
1474#endif
1475/*
1476 Read and decompress up to nitems items of size size from file into buf,
1477 otherwise operating as gzread() does. This duplicates the interface of
1478 stdio's fread(), with size_t request and return types. If the library
1479 defines size_t, then z_size_t is identical to size_t. If not, then z_size_t
1480 is an unsigned integer type that can contain a pointer.
1481
1482 gzfread() returns the number of full items read of size size, or zero if
1483 the end of the file was reached and a full item could not be read, or if
1484 there was an error. gzerror() must be consulted if zero is returned in
1485 order to determine if there was an error. If the multiplication of size and
1486 nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
1487 is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
1488
1489 In the event that the end of file is reached and only a partial item is
1490 available at the end, i.e. the remaining uncompressed data length is not a
1491 multiple of size, then the final partial item is nevetheless read into buf
1492 and the end-of-file flag is set. The length of the partial item read is not
1493 provided, but could be inferred from the result of gztell(). This behavior
1494 is the same as the behavior of fread() implementations in common libraries,
1495 but it prevents the direct use of gzfread() to read a concurrently written
1496 file, reseting and retrying on end-of-file, when size is not 1.
1497*/
1498
1499ZEXTERN int ZEXPORT gzwrite OF((gzFile file, voidpc buf, unsigned len));
1500/*
1501 Compress and write the len uncompressed bytes at buf to file. gzwrite
1502 returns the number of uncompressed bytes written or 0 in case of error.
1503*/
1504
1505#if !defined(__ANDROID__) || __ANDROID_API__ >= 28
1506ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size,
1507 z_size_t nitems, gzFile file));
1508#endif
1509/*
1510 Compress and write nitems items of size size from buf to file, duplicating
1511 the interface of stdio's fwrite(), with size_t request and return types. If
1512 the library defines size_t, then z_size_t is identical to size_t. If not,
1513 then z_size_t is an unsigned integer type that can contain a pointer.
1514
1515 gzfwrite() returns the number of full items written of size size, or zero
1516 if there was an error. If the multiplication of size and nitems overflows,
1517 i.e. the product does not fit in a z_size_t, then nothing is written, zero
1518 is returned, and the error state is set to Z_STREAM_ERROR.
1519*/
1520
1521ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
1522/*
1523 Convert, format, compress, and write the arguments (...) to file under
1524 control of the string format, as in fprintf. gzprintf returns the number of
1525 uncompressed bytes actually written, or a negative zlib error code in case
1526 of error. The number of uncompressed bytes written is limited to 8191, or
1527 one less than the buffer size given to gzbuffer(). The caller should assure
1528 that this limit is not exceeded. If it is exceeded, then gzprintf() will
1529 return an error (0) with nothing written. In this case, there may also be a
1530 buffer overflow with unpredictable consequences, which is possible only if
1531 zlib was compiled with the insecure functions sprintf() or vsprintf(),
1532 because the secure snprintf() or vsnprintf() functions were not available.
1533 This can be determined using zlibCompileFlags().
1534*/
1535
1536ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1537/*
1538 Compress and write the given null-terminated string s to file, excluding
1539 the terminating null character.
1540
1541 gzputs returns the number of characters written, or -1 in case of error.
1542*/
1543
1544ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1545/*
1546 Read and decompress bytes from file into buf, until len-1 characters are
1547 read, or until a newline character is read and transferred to buf, or an
1548 end-of-file condition is encountered. If any characters are read or if len
1549 is one, the string is terminated with a null character. If no characters
1550 are read due to an end-of-file or len is less than one, then the buffer is
1551 left untouched.
1552
1553 gzgets returns buf which is a null-terminated string, or it returns NULL
1554 for end-of-file or in case of error. If there was an error, the contents at
1555 buf are indeterminate.
1556*/
1557
1558ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1559/*
1560 Compress and write c, converted to an unsigned char, into file. gzputc
1561 returns the value that was written, or -1 in case of error.
1562*/
1563
1564ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1565/*
1566 Read and decompress one byte from file. gzgetc returns this byte or -1
1567 in case of end of file or error. This is implemented as a macro for speed.
1568 As such, it does not do all of the checking the other functions do. I.e.
1569 it does not check to see if file is NULL, nor whether the structure file
1570 points to has been clobbered or not.
1571*/
1572
1573ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1574/*
1575 Push c back onto the stream for file to be read as the first character on
1576 the next read. At least one character of push-back is always allowed.
1577 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
1578 fail if c is -1, and may fail if a character has been pushed but not read
1579 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
1580 output buffer size of pushed characters is allowed. (See gzbuffer above.)
1581 The pushed character will be discarded if the stream is repositioned with
1582 gzseek() or gzrewind().
1583*/
1584
1585ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1586/*
1587 Flush all pending output to file. The parameter flush is as in the
1588 deflate() function. The return value is the zlib error number (see function
1589 gzerror below). gzflush is only permitted when writing.
1590
1591 If the flush parameter is Z_FINISH, the remaining data is written and the
1592 gzip stream is completed in the output. If gzwrite() is called again, a new
1593 gzip stream will be started in the output. gzread() is able to read such
1594 concatenated gzip streams.
1595
1596 gzflush should be called only when strictly necessary because it will
1597 degrade compression if called too often.
1598*/
1599
1600/*
1601ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1602 z_off_t offset, int whence));
1603
1604 Set the starting position to offset relative to whence for the next gzread
1605 or gzwrite on file. The offset represents a number of bytes in the
1606 uncompressed data stream. The whence parameter is defined as in lseek(2);
1607 the value SEEK_END is not supported.
1608
1609 If the file is opened for reading, this function is emulated but can be
1610 extremely slow. If the file is opened for writing, only forward seeks are
1611 supported; gzseek then compresses a sequence of zeroes up to the new
1612 starting position.
1613
1614 gzseek returns the resulting offset location as measured in bytes from
1615 the beginning of the uncompressed stream, or -1 in case of error, in
1616 particular if the file is opened for writing and the new starting position
1617 would be before the current position.
1618*/
1619
1620ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
1621/*
1622 Rewind file. This function is supported only for reading.
1623
1624 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET).
1625*/
1626
1627/*
1628ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1629
1630 Return the starting position for the next gzread or gzwrite on file.
1631 This position represents a number of bytes in the uncompressed data stream,
1632 and is zero when starting, even if appending or reading a gzip stream from
1633 the middle of a file using gzdopen().
1634
1635 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1636*/
1637
1638/*
1639ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
1640
1641 Return the current compressed (actual) read or write offset of file. This
1642 offset includes the count of bytes that precede the gzip stream, for example
1643 when appending or when using gzdopen() for reading. When reading, the
1644 offset does not include as yet unused buffered input. This information can
1645 be used for a progress indicator. On error, gzoffset() returns -1.
1646*/
1647
1648ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1649/*
1650 Return true (1) if the end-of-file indicator for file has been set while
1651 reading, false (0) otherwise. Note that the end-of-file indicator is set
1652 only if the read tried to go past the end of the input, but came up short.
1653 Therefore, just like feof(), gzeof() may return false even if there is no
1654 more data to read, in the event that the last read request was for the exact
1655 number of bytes remaining in the input file. This will happen if the input
1656 file size is an exact multiple of the buffer size.
1657
1658 If gzeof() returns true, then the read functions will return no more data,
1659 unless the end-of-file indicator is reset by gzclearerr() and the input file
1660 has grown since the previous end of file was detected.
1661*/
1662
1663ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1664/*
1665 Return true (1) if file is being copied directly while reading, or false
1666 (0) if file is a gzip stream being decompressed.
1667
1668 If the input file is empty, gzdirect() will return true, since the input
1669 does not contain a gzip stream.
1670
1671 If gzdirect() is used immediately after gzopen() or gzdopen() it will
1672 cause buffers to be allocated to allow reading the file to determine if it
1673 is a gzip file. Therefore if gzbuffer() is used, it should be called before
1674 gzdirect().
1675
1676 When writing, gzdirect() returns true (1) if transparent writing was
1677 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note:
1678 gzdirect() is not needed when writing. Transparent writing must be
1679 explicitly requested, so the application already knows the answer. When
1680 linking statically, using gzdirect() will include all of the zlib code for
1681 gzip file reading and decompression, which may not be desired.)
1682*/
1683
1684ZEXTERN int ZEXPORT gzclose OF((gzFile file));
1685/*
1686 Flush all pending output for file, if necessary, close file and
1687 deallocate the (de)compression state. Note that once file is closed, you
1688 cannot call gzerror with file, since its structures have been deallocated.
1689 gzclose must not be called more than once on the same file, just as free
1690 must not be called more than once on the same allocation.
1691
1692 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
1693 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
1694 last read ended in the middle of a gzip stream, or Z_OK on success.
1695*/
1696
1697ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
1698ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
1699/*
1700 Same as gzclose(), but gzclose_r() is only for use when reading, and
1701 gzclose_w() is only for use when writing or appending. The advantage to
1702 using these instead of gzclose() is that they avoid linking in zlib
1703 compression or decompression code that is not used when only reading or only
1704 writing respectively. If gzclose() is used, then both compression and
1705 decompression code will be included the application when linking to a static
1706 zlib library.
1707*/
1708
1709ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1710/*
1711 Return the error message for the last error which occurred on file.
1712 errnum is set to zlib error number. If an error occurred in the file system
1713 and not in the compression library, errnum is set to Z_ERRNO and the
1714 application may consult errno to get the exact error code.
1715
1716 The application must not modify the returned string. Future calls to
1717 this function may invalidate the previously returned string. If file is
1718 closed, then the string previously returned by gzerror will no longer be
1719 available.
1720
1721 gzerror() should be used to distinguish errors from end-of-file for those
1722 functions above that do not distinguish those cases in their return values.
1723*/
1724
1725ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1726/*
1727 Clear the error and end-of-file flags for file. This is analogous to the
1728 clearerr() function in stdio. This is useful for continuing to read a gzip
1729 file that is being written concurrently.
1730*/
1731
1732#endif /* !Z_SOLO */
1733
1734 /* checksum functions */
1735
1736/*
1737 These functions are not related to compression but are exported
1738 anyway because they might be useful in applications using the compression
1739 library.
1740*/
1741
1742ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1743/*
1744 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1745 return the updated checksum. An Adler-32 value is in the range of a 32-bit
1746 unsigned integer. If buf is Z_NULL, this function returns the required
1747 initial value for the checksum.
1748
1749 An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
1750 much faster.
1751
1752 Usage example:
1753
1754 uLong adler = adler32(0L, Z_NULL, 0);
1755
1756 while (read_buffer(buffer, length) != EOF) {
1757 adler = adler32(adler, buffer, length);
1758 }
1759 if (adler != original_adler) error();
1760*/
1761
1762#if !defined(__ANDROID__) || __ANDROID_API__ >= 28
1763ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf,
1764 z_size_t len));
1765#endif
1766/*
1767 Same as adler32(), but with a size_t length.
1768*/
1769
1770/*
1771ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1772 z_off_t len2));
1773
1774 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
1775 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1776 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
1777 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note
1778 that the z_off_t type (like off_t) is a signed integer. If len2 is
1779 negative, the result has no meaning or utility.
1780*/
1781
1782ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
1783/*
1784 Update a running CRC-32 with the bytes buf[0..len-1] and return the
1785 updated CRC-32. A CRC-32 value is in the range of a 32-bit unsigned integer.
1786 If buf is Z_NULL, this function returns the required initial value for the
1787 crc. Pre- and post-conditioning (one's complement) is performed within this
1788 function so it shouldn't be done by the application.
1789
1790 Usage example:
1791
1792 uLong crc = crc32(0L, Z_NULL, 0);
1793
1794 while (read_buffer(buffer, length) != EOF) {
1795 crc = crc32(crc, buffer, length);
1796 }
1797 if (crc != original_crc) error();
1798*/
1799
1800#if !defined(__ANDROID__) || __ANDROID_API__ >= 28
1801ZEXTERN uLong ZEXPORT crc32_z OF((uLong crc, const Bytef *buf,
1802 z_size_t len));
1803#endif
1804/*
1805 Same as crc32(), but with a size_t length.
1806*/
1807
1808/*
1809ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1810
1811 Combine two CRC-32 check values into one. For two sequences of bytes,
1812 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1813 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1814 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1815 len2.
1816*/
1817
1818/*
1819ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t len2));
1820
1821 Return the operator corresponding to length len2, to be used with
1822 crc32_combine_op().
1823*/
1824
1825ZEXTERN uLong ZEXPORT crc32_combine_op OF((uLong crc1, uLong crc2, uLong op));
1826/*
1827 Give the same result as crc32_combine(), using op in place of len2. op is
1828 is generated from len2 by crc32_combine_gen(). This will be faster than
1829 crc32_combine() if the generated op is used more than once.
1830*/
1831
1832
1833 /* various hacks, don't look :) */
1834
1835/* deflateInit and inflateInit are macros to allow checking the zlib version
1836 * and the compiler's view of z_stream:
1837 */
1838ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1839 const char *version, int stream_size));
1840ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1841 const char *version, int stream_size));
1842ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1843 int windowBits, int memLevel,
1844 int strategy, const char *version,
1845 int stream_size));
1846ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
1847 const char *version, int stream_size));
1848ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1849 unsigned char FAR *window,
1850 const char *version,
1851 int stream_size));
1852#ifdef Z_PREFIX_SET
1853# define z_deflateInit(strm, level) \
1854 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1855# define z_inflateInit(strm) \
1856 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1857# define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1858 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1859 (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1860# define z_inflateInit2(strm, windowBits) \
1861 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1862 (int)sizeof(z_stream))
1863# define z_inflateBackInit(strm, windowBits, window) \
1864 inflateBackInit_((strm), (windowBits), (window), \
1865 ZLIB_VERSION, (int)sizeof(z_stream))
1866#else
1867# define deflateInit(strm, level) \
1868 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1869# define inflateInit(strm) \
1870 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1871# define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1872 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1873 (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1874# define inflateInit2(strm, windowBits) \
1875 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1876 (int)sizeof(z_stream))
1877# define inflateBackInit(strm, windowBits, window) \
1878 inflateBackInit_((strm), (windowBits), (window), \
1879 ZLIB_VERSION, (int)sizeof(z_stream))
1880#endif
1881
1882#ifndef Z_SOLO
1883
1884/* gzgetc() macro and its supporting function and exposed data structure. Note
1885 * that the real internal state is much larger than the exposed structure.
1886 * This abbreviated structure exposes just enough for the gzgetc() macro. The
1887 * user should not mess with these exposed elements, since their names or
1888 * behavior could change in the future, perhaps even capriciously. They can
1889 * only be used by the gzgetc() macro. You have been warned.
1890 */
1891struct gzFile_s {
1892 unsigned have;
1893 unsigned char *next;
1894 z_off64_t pos;
1895};
1896ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */
1897#ifdef Z_PREFIX_SET
1898# undef z_gzgetc
1899# define z_gzgetc(g) \
1900 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1901#elif defined(Z_CR_PREFIX_SET)
1902# undef gzgetc
1903# define gzgetc(g) \
1904 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) \
1905 : (Cr_z_gzgetc)(g))
1906#else
1907# define gzgetc(g) \
1908 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1909#endif
1910
1911/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1912 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
1913 * both are true, the application gets the *64 functions, and the regular
1914 * functions are changed to 64 bits) -- in case these are set on systems
1915 * without large file support, _LFS64_LARGEFILE must also be true
1916 */
1917#ifdef Z_LARGE64
1918 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1919 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
1920 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
1921 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
1922 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
1923 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
1924 ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off64_t));
1925#endif
1926
1927#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
1928# ifdef Z_PREFIX_SET
1929# define z_gzopen z_gzopen64
1930# define z_gzseek z_gzseek64
1931# define z_gztell z_gztell64
1932# define z_gzoffset z_gzoffset64
1933# define z_adler32_combine z_adler32_combine64
1934# define z_crc32_combine z_crc32_combine64
1935# define z_crc32_combine_gen z_crc32_combine_gen64
1936# else
1937# ifdef gzopen
1938# undef gzopen
1939# endif
1940# define gzopen gzopen64
1941# ifdef gzseek
1942# undef gzseek
1943# endif
1944# define gzseek gzseek64
1945# ifdef gztell
1946# undef gztell
1947# endif
1948# define gztell gztell64
1949# ifdef gzoffset
1950# undef gzoffset
1951# endif
1952# define gzoffset gzoffset64
1953# ifdef adler32_combine
1954# undef adler32_combine
1955# endif
1956# define adler32_combine adler32_combine64
1957# ifdef crc32_combine
1958# undef crc32_combine
1959# endif
1960# ifdef crc32_combine64
1961# undef crc32_combine64
1962# endif
1963# ifdef crc32_combine_gen
1964# undef crc32_combine_gen
1965# endif
1966# ifdef crc32_combine_op
1967# undef crc32_combine_op
1968# endif
1969# endif
1970# ifndef Z_LARGE64
1971 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1972 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
1973 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
1974 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
1975 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
1976 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
1977 ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off_t));
1978# endif
1979#else
1980 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
1981 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
1982 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
1983 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
1984 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1985 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1986 ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t));
1987#endif
1988
1989#else /* Z_SOLO */
1990
1991 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1992 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1993 ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t));
1994
1995#endif /* !Z_SOLO */
1996
1997/* undocumented functions */
1998ZEXTERN const char * ZEXPORT zError OF((int));
1999ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
2000ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void));
2001ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
2002#if !defined(__ANDROID__) || __ANDROID_API__ >= 28
2003ZEXTERN int ZEXPORT inflateValidate OF((z_streamp, int));
2004#endif
2005#if !defined(__ANDROID__) || __ANDROID_API__ >= 28
2006ZEXTERN unsigned long ZEXPORT inflateCodesUsed OF ((z_streamp));
2007#endif
2008ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp));
2009ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp));
2010#if defined(_WIN32) && !defined(Z_SOLO)
2011ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path,
2012 const char *mode));
2013#endif
2014#if defined(STDC) || defined(Z_HAVE_STDARG_H)
2015# ifndef Z_SOLO
2016# if !defined(__ANDROID__) || __ANDROID_API__ >= 19
2017ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file,
2018 const char *format,
2019 va_list va));
2020# endif
2021# endif
2022#endif
2023
2024#ifdef __cplusplus
2025}
2026#endif
2027
2028#endif /* ZLIB_H */