osx: disable app-nap during serial comm (#687)
[proxmark3-svn] / zlib / zlib.h
1 /* zlib.h -- interface of the 'zlib' general purpose compression library
2 version 1.2.8, April 28th, 2013
3
4 Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
5
6 This software is provided 'as-is', without any express or implied
7 warranty. In no event will the authors be held liable for any damages
8 arising from the use of this software.
9
10 Permission is granted to anyone to use this software for any purpose,
11 including commercial applications, and to alter it and redistribute it
12 freely, subject to the following restrictions:
13
14 1. The origin of this software must not be misrepresented; you must not
15 claim that you wrote the original software. If you use this software
16 in a product, an acknowledgment in the product documentation would be
17 appreciated but is not required.
18 2. Altered source versions must be plainly marked as such, and must not be
19 misrepresented as being the original software.
20 3. This notice may not be removed or altered from any source distribution.
21
22 Jean-loup Gailly Mark Adler
23 jloup@gzip.org madler@alumni.caltech.edu
24
25
26 The data format used by the zlib library is described by RFCs (Request for
27 Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
28 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
29 */
30
31 //-----------------------------------------------------------------------------
32 // This version of zlib is modified for use within the Proxmark3 project.
33 // Files from the original distribution which are not required for this
34 // purpose are not included. All modifications can easily be found
35 // by searching for #ifdef ZLIB_PM3_TUNED and #ifndef ZLIB_PM3_TUNED.
36 //-----------------------------------------------------------------------------
37
38 #ifndef ZLIB_H
39 #define ZLIB_H
40
41 #include "zconf.h"
42
43 #ifdef __cplusplus
44 extern "C" {
45 #endif
46
47 #ifndef ZLIB_PM3_TUNED
48 #define ZLIB_VERSION "1.2.8"
49 #define ZLIB_VERNUM 0x1280
50 #define ZLIB_VER_MAJOR 1
51 #define ZLIB_VER_MINOR 2
52 #define ZLIB_VER_REVISION 8
53 #define ZLIB_VER_SUBREVISION 0
54 #else
55 #define ZLIB_VERSION "1.2.8.f-Proxmark3"
56 #define ZLIB_VERNUM 0x128f
57 #define ZLIB_VER_MAJOR 1
58 #define ZLIB_VER_MINOR 2
59 #define ZLIB_VER_REVISION 8
60 #define ZLIB_VER_SUBREVISION f
61 #endif
62
63
64
65 /*
66 The 'zlib' compression library provides in-memory compression and
67 decompression functions, including integrity checks of the uncompressed data.
68 This version of the library supports only one compression method (deflation)
69 but other algorithms will be added later and will have the same stream
70 interface.
71
72 Compression can be done in a single step if the buffers are large enough,
73 or can be done by repeated calls of the compression function. In the latter
74 case, the application must provide more input and/or consume the output
75 (providing more output space) before each call.
76
77 The compressed data format used by default by the in-memory functions is
78 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
79 around a deflate stream, which is itself documented in RFC 1951.
80
81 The library also supports reading and writing files in gzip (.gz) format
82 with an interface similar to that of stdio using the functions that start
83 with "gz". The gzip format is different from the zlib format. gzip is a
84 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
85
86 This library can optionally read and write gzip streams in memory as well.
87
88 The zlib format was designed to be compact and fast for use in memory
89 and on communications channels. The gzip format was designed for single-
90 file compression on file systems, has a larger header than zlib to maintain
91 directory information, and uses a different, slower check method than zlib.
92
93 The library does not install any signal handler. The decoder checks
94 the consistency of the compressed data, so the library should never crash
95 even in case of corrupted input.
96 */
97
98 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
99 typedef void (*free_func) OF((voidpf opaque, voidpf address));
100
101 struct internal_state;
102
103 typedef struct z_stream_s {
104 z_const Bytef *next_in; /* next input byte */
105 uInt avail_in; /* number of bytes available at next_in */
106 uLong total_in; /* total number of input bytes read so far */
107
108 Bytef *next_out; /* next output byte should be put there */
109 uInt avail_out; /* remaining free space at next_out */
110 uLong total_out; /* total number of bytes output so far */
111
112 z_const char *msg; /* last error message, NULL if no error */
113 struct internal_state FAR *state; /* not visible by applications */
114
115 alloc_func zalloc; /* used to allocate the internal state */
116 free_func zfree; /* used to free the internal state */
117 voidpf opaque; /* private data object passed to zalloc and zfree */
118
119 int data_type; /* best guess about the data type: binary or text */
120 uLong adler; /* adler32 value of the uncompressed data */
121 uLong reserved; /* reserved for future use */
122 } z_stream;
123
124 typedef z_stream FAR *z_streamp;
125
126 /*
127 gzip header information passed to and from zlib routines. See RFC 1952
128 for more details on the meanings of these fields.
129 */
130 typedef struct gz_header_s {
131 int text; /* true if compressed data believed to be text */
132 uLong time; /* modification time */
133 int xflags; /* extra flags (not used when writing a gzip file) */
134 int os; /* operating system */
135 Bytef *extra; /* pointer to extra field or Z_NULL if none */
136 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
137 uInt extra_max; /* space at extra (only when reading header) */
138 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
139 uInt name_max; /* space at name (only when reading header) */
140 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
141 uInt comm_max; /* space at comment (only when reading header) */
142 int hcrc; /* true if there was or will be a header crc */
143 int done; /* true when done reading gzip header (not used
144 when writing a gzip file) */
145 } gz_header;
146
147 typedef gz_header FAR *gz_headerp;
148
149 /*
150 The application must update next_in and avail_in when avail_in has dropped
151 to zero. It must update next_out and avail_out when avail_out has dropped
152 to zero. The application must initialize zalloc, zfree and opaque before
153 calling the init function. All other fields are set by the compression
154 library and must not be updated by the application.
155
156 The opaque value provided by the application will be passed as the first
157 parameter for calls of zalloc and zfree. This can be useful for custom
158 memory management. The compression library attaches no meaning to the
159 opaque value.
160
161 zalloc must return Z_NULL if there is not enough memory for the object.
162 If zlib is used in a multi-threaded application, zalloc and zfree must be
163 thread safe.
164
165 On 16-bit systems, the functions zalloc and zfree must be able to allocate
166 exactly 65536 bytes, but will not be required to allocate more than this if
167 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
168 returned by zalloc for objects of exactly 65536 bytes *must* have their
169 offset normalized to zero. The default allocation function provided by this
170 library ensures this (see zutil.c). To reduce memory requirements and avoid
171 any allocation of 64K objects, at the expense of compression ratio, compile
172 the library with -DMAX_WBITS=14 (see zconf.h).
173
174 The fields total_in and total_out can be used for statistics or progress
175 reports. After compression, total_in holds the total size of the
176 uncompressed data and may be saved for use in the decompressor (particularly
177 if the decompressor wants to decompress everything in a single step).
178 */
179
180 /* constants */
181
182 #define Z_NO_FLUSH 0
183 #define Z_PARTIAL_FLUSH 1
184 #define Z_SYNC_FLUSH 2
185 #define Z_FULL_FLUSH 3
186 #define Z_FINISH 4
187 #define Z_BLOCK 5
188 #define Z_TREES 6
189 /* Allowed flush values; see deflate() and inflate() below for details */
190
191 #define Z_OK 0
192 #define Z_STREAM_END 1
193 #define Z_NEED_DICT 2
194 #define Z_ERRNO (-1)
195 #define Z_STREAM_ERROR (-2)
196 #define Z_DATA_ERROR (-3)
197 #define Z_MEM_ERROR (-4)
198 #define Z_BUF_ERROR (-5)
199 #define Z_VERSION_ERROR (-6)
200 /* Return codes for the compression/decompression functions. Negative values
201 * are errors, positive values are used for special but normal events.
202 */
203
204 #define Z_NO_COMPRESSION 0
205 #define Z_BEST_SPEED 1
206 #define Z_BEST_COMPRESSION 9
207 #define Z_DEFAULT_COMPRESSION (-1)
208 /* compression levels */
209
210 #define Z_FILTERED 1
211 #define Z_HUFFMAN_ONLY 2
212 #define Z_RLE 3
213 #define Z_FIXED 4
214 #define Z_DEFAULT_STRATEGY 0
215 /* compression strategy; see deflateInit2() below for details */
216
217 #define Z_BINARY 0
218 #define Z_TEXT 1
219 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
220 #define Z_UNKNOWN 2
221 /* Possible values of the data_type field (though see inflate()) */
222
223 #define Z_DEFLATED 8
224 /* The deflate compression method (the only one supported in this version) */
225
226 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
227
228 #define zlib_version zlibVersion()
229 /* for compatibility with versions < 1.0.2 */
230
231
232 /* basic functions */
233
234 ZEXTERN const char * ZEXPORT zlibVersion OF((void));
235 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
236 If the first character differs, the library code actually used is not
237 compatible with the zlib.h header file used by the application. This check
238 is automatically made by deflateInit and inflateInit.
239 */
240
241 /*
242 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
243
244 Initializes the internal stream state for compression. The fields
245 zalloc, zfree and opaque must be initialized before by the caller. If
246 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
247 allocation functions.
248
249 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
250 1 gives best speed, 9 gives best compression, 0 gives no compression at all
251 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
252 requests a default compromise between speed and compression (currently
253 equivalent to level 6).
254
255 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
256 memory, Z_STREAM_ERROR if level is not a valid compression level, or
257 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
258 with the version assumed by the caller (ZLIB_VERSION). msg is set to null
259 if there is no error message. deflateInit does not perform any compression:
260 this will be done by deflate().
261 */
262
263
264 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
265 /*
266 deflate compresses as much data as possible, and stops when the input
267 buffer becomes empty or the output buffer becomes full. It may introduce
268 some output latency (reading input without producing any output) except when
269 forced to flush.
270
271 The detailed semantics are as follows. deflate performs one or both of the
272 following actions:
273
274 - Compress more input starting at next_in and update next_in and avail_in
275 accordingly. If not all input can be processed (because there is not
276 enough room in the output buffer), next_in and avail_in are updated and
277 processing will resume at this point for the next call of deflate().
278
279 - Provide more output starting at next_out and update next_out and avail_out
280 accordingly. This action is forced if the parameter flush is non zero.
281 Forcing flush frequently degrades the compression ratio, so this parameter
282 should be set only when necessary (in interactive applications). Some
283 output may be provided even if flush is not set.
284
285 Before the call of deflate(), the application should ensure that at least
286 one of the actions is possible, by providing more input and/or consuming more
287 output, and updating avail_in or avail_out accordingly; avail_out should
288 never be zero before the call. The application can consume the compressed
289 output when it wants, for example when the output buffer is full (avail_out
290 == 0), or after each call of deflate(). If deflate returns Z_OK and with
291 zero avail_out, it must be called again after making room in the output
292 buffer because there might be more output pending.
293
294 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
295 decide how much data to accumulate before producing output, in order to
296 maximize compression.
297
298 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
299 flushed to the output buffer and the output is aligned on a byte boundary, so
300 that the decompressor can get all input data available so far. (In
301 particular avail_in is zero after the call if enough output space has been
302 provided before the call.) Flushing may degrade compression for some
303 compression algorithms and so it should be used only when necessary. This
304 completes the current deflate block and follows it with an empty stored block
305 that is three bits plus filler bits to the next byte, followed by four bytes
306 (00 00 ff ff).
307
308 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
309 output buffer, but the output is not aligned to a byte boundary. All of the
310 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
311 This completes the current deflate block and follows it with an empty fixed
312 codes block that is 10 bits long. This assures that enough bytes are output
313 in order for the decompressor to finish the block before the empty fixed code
314 block.
315
316 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
317 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
318 seven bits of the current block are held to be written as the next byte after
319 the next deflate block is completed. In this case, the decompressor may not
320 be provided enough bits at this point in order to complete decompression of
321 the data provided so far to the compressor. It may need to wait for the next
322 block to be emitted. This is for advanced applications that need to control
323 the emission of deflate blocks.
324
325 If flush is set to Z_FULL_FLUSH, all output is flushed as with
326 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
327 restart from this point if previous compressed data has been damaged or if
328 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
329 compression.
330
331 If deflate returns with avail_out == 0, this function must be called again
332 with the same value of the flush parameter and more output space (updated
333 avail_out), until the flush is complete (deflate returns with non-zero
334 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
335 avail_out is greater than six to avoid repeated flush markers due to
336 avail_out == 0 on return.
337
338 If the parameter flush is set to Z_FINISH, pending input is processed,
339 pending output is flushed and deflate returns with Z_STREAM_END if there was
340 enough output space; if deflate returns with Z_OK, this function must be
341 called again with Z_FINISH and more output space (updated avail_out) but no
342 more input data, until it returns with Z_STREAM_END or an error. After
343 deflate has returned Z_STREAM_END, the only possible operations on the stream
344 are deflateReset or deflateEnd.
345
346 Z_FINISH can be used immediately after deflateInit if all the compression
347 is to be done in a single step. In this case, avail_out must be at least the
348 value returned by deflateBound (see below). Then deflate is guaranteed to
349 return Z_STREAM_END. If not enough output space is provided, deflate will
350 not return Z_STREAM_END, and it must be called again as described above.
351
352 deflate() sets strm->adler to the adler32 checksum of all input read
353 so far (that is, total_in bytes).
354
355 deflate() may update strm->data_type if it can make a good guess about
356 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
357 binary. This field is only for information purposes and does not affect the
358 compression algorithm in any manner.
359
360 deflate() returns Z_OK if some progress has been made (more input
361 processed or more output produced), Z_STREAM_END if all input has been
362 consumed and all output has been produced (only when flush is set to
363 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
364 if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
365 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
366 fatal, and deflate() can be called again with more input and more output
367 space to continue compressing.
368 */
369
370
371 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
372 /*
373 All dynamically allocated data structures for this stream are freed.
374 This function discards any unprocessed input and does not flush any pending
375 output.
376
377 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
378 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
379 prematurely (some input or output was discarded). In the error case, msg
380 may be set but then points to a static string (which must not be
381 deallocated).
382 */
383
384
385 /*
386 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
387
388 Initializes the internal stream state for decompression. The fields
389 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
390 the caller. If next_in is not Z_NULL and avail_in is large enough (the
391 exact value depends on the compression method), inflateInit determines the
392 compression method from the zlib header and allocates all data structures
393 accordingly; otherwise the allocation will be deferred to the first call of
394 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
395 use default allocation functions.
396
397 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
398 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
399 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
400 invalid, such as a null pointer to the structure. msg is set to null if
401 there is no error message. inflateInit does not perform any decompression
402 apart from possibly reading the zlib header if present: actual decompression
403 will be done by inflate(). (So next_in and avail_in may be modified, but
404 next_out and avail_out are unused and unchanged.) The current implementation
405 of inflateInit() does not process any header information -- that is deferred
406 until inflate() is called.
407 */
408
409
410 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
411 /*
412 inflate decompresses as much data as possible, and stops when the input
413 buffer becomes empty or the output buffer becomes full. It may introduce
414 some output latency (reading input without producing any output) except when
415 forced to flush.
416
417 The detailed semantics are as follows. inflate performs one or both of the
418 following actions:
419
420 - Decompress more input starting at next_in and update next_in and avail_in
421 accordingly. If not all input can be processed (because there is not
422 enough room in the output buffer), next_in is updated and processing will
423 resume at this point for the next call of inflate().
424
425 - Provide more output starting at next_out and update next_out and avail_out
426 accordingly. inflate() provides as much output as possible, until there is
427 no more input data or no more space in the output buffer (see below about
428 the flush parameter).
429
430 Before the call of inflate(), the application should ensure that at least
431 one of the actions is possible, by providing more input and/or consuming more
432 output, and updating the next_* and avail_* values accordingly. The
433 application can consume the uncompressed output when it wants, for example
434 when the output buffer is full (avail_out == 0), or after each call of
435 inflate(). If inflate returns Z_OK and with zero avail_out, it must be
436 called again after making room in the output buffer because there might be
437 more output pending.
438
439 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
440 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
441 output as possible to the output buffer. Z_BLOCK requests that inflate()
442 stop if and when it gets to the next deflate block boundary. When decoding
443 the zlib or gzip format, this will cause inflate() to return immediately
444 after the header and before the first block. When doing a raw inflate,
445 inflate() will go ahead and process the first block, and will return when it
446 gets to the end of that block, or when it runs out of data.
447
448 The Z_BLOCK option assists in appending to or combining deflate streams.
449 Also to assist in this, on return inflate() will set strm->data_type to the
450 number of unused bits in the last byte taken from strm->next_in, plus 64 if
451 inflate() is currently decoding the last block in the deflate stream, plus
452 128 if inflate() returned immediately after decoding an end-of-block code or
453 decoding the complete header up to just before the first byte of the deflate
454 stream. The end-of-block will not be indicated until all of the uncompressed
455 data from that block has been written to strm->next_out. The number of
456 unused bits may in general be greater than seven, except when bit 7 of
457 data_type is set, in which case the number of unused bits will be less than
458 eight. data_type is set as noted here every time inflate() returns for all
459 flush options, and so can be used to determine the amount of currently
460 consumed input in bits.
461
462 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
463 end of each deflate block header is reached, before any actual data in that
464 block is decoded. This allows the caller to determine the length of the
465 deflate block header for later use in random access within a deflate block.
466 256 is added to the value of strm->data_type when inflate() returns
467 immediately after reaching the end of the deflate block header.
468
469 inflate() should normally be called until it returns Z_STREAM_END or an
470 error. However if all decompression is to be performed in a single step (a
471 single call of inflate), the parameter flush should be set to Z_FINISH. In
472 this case all pending input is processed and all pending output is flushed;
473 avail_out must be large enough to hold all of the uncompressed data for the
474 operation to complete. (The size of the uncompressed data may have been
475 saved by the compressor for this purpose.) The use of Z_FINISH is not
476 required to perform an inflation in one step. However it may be used to
477 inform inflate that a faster approach can be used for the single inflate()
478 call. Z_FINISH also informs inflate to not maintain a sliding window if the
479 stream completes, which reduces inflate's memory footprint. If the stream
480 does not complete, either because not all of the stream is provided or not
481 enough output space is provided, then a sliding window will be allocated and
482 inflate() can be called again to continue the operation as if Z_NO_FLUSH had
483 been used.
484
485 In this implementation, inflate() always flushes as much output as
486 possible to the output buffer, and always uses the faster approach on the
487 first call. So the effects of the flush parameter in this implementation are
488 on the return value of inflate() as noted below, when inflate() returns early
489 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
490 memory for a sliding window when Z_FINISH is used.
491
492 If a preset dictionary is needed after this call (see inflateSetDictionary
493 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
494 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
495 strm->adler to the Adler-32 checksum of all output produced so far (that is,
496 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
497 below. At the end of the stream, inflate() checks that its computed adler32
498 checksum is equal to that saved by the compressor and returns Z_STREAM_END
499 only if the checksum is correct.
500
501 inflate() can decompress and check either zlib-wrapped or gzip-wrapped
502 deflate data. The header type is detected automatically, if requested when
503 initializing with inflateInit2(). Any information contained in the gzip
504 header is not retained, so applications that need that information should
505 instead use raw inflate, see inflateInit2() below, or inflateBack() and
506 perform their own processing of the gzip header and trailer. When processing
507 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
508 producted so far. The CRC-32 is checked against the gzip trailer.
509
510 inflate() returns Z_OK if some progress has been made (more input processed
511 or more output produced), Z_STREAM_END if the end of the compressed data has
512 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
513 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
514 corrupted (input stream not conforming to the zlib format or incorrect check
515 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
516 next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
517 Z_BUF_ERROR if no progress is possible or if there was not enough room in the
518 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
519 inflate() can be called again with more input and more output space to
520 continue decompressing. If Z_DATA_ERROR is returned, the application may
521 then call inflateSync() to look for a good compression block if a partial
522 recovery of the data is desired.
523 */
524
525
526 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
527 /*
528 All dynamically allocated data structures for this stream are freed.
529 This function discards any unprocessed input and does not flush any pending
530 output.
531
532 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
533 was inconsistent. In the error case, msg may be set but then points to a
534 static string (which must not be deallocated).
535 */
536
537
538 /* Advanced functions */
539
540 /*
541 The following functions are needed only in some special applications.
542 */
543
544 /*
545 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
546 int level,
547 int method,
548 int windowBits,
549 int memLevel,
550 int strategy));
551
552 This is another version of deflateInit with more compression options. The
553 fields next_in, zalloc, zfree and opaque must be initialized before by the
554 caller.
555
556 The method parameter is the compression method. It must be Z_DEFLATED in
557 this version of the library.
558
559 The windowBits parameter is the base two logarithm of the window size
560 (the size of the history buffer). It should be in the range 8..15 for this
561 version of the library. Larger values of this parameter result in better
562 compression at the expense of memory usage. The default value is 15 if
563 deflateInit is used instead.
564
565 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
566 determines the window size. deflate() will then generate raw deflate data
567 with no zlib header or trailer, and will not compute an adler32 check value.
568
569 windowBits can also be greater than 15 for optional gzip encoding. Add
570 16 to windowBits to write a simple gzip header and trailer around the
571 compressed data instead of a zlib wrapper. The gzip header will have no
572 file name, no extra data, no comment, no modification time (set to zero), no
573 header crc, and the operating system will be set to 255 (unknown). If a
574 gzip stream is being written, strm->adler is a crc32 instead of an adler32.
575
576 The memLevel parameter specifies how much memory should be allocated
577 for the internal compression state. memLevel=1 uses minimum memory but is
578 slow and reduces compression ratio; memLevel=9 uses maximum memory for
579 optimal speed. The default value is 8. See zconf.h for total memory usage
580 as a function of windowBits and memLevel.
581
582 The strategy parameter is used to tune the compression algorithm. Use the
583 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
584 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
585 string match), or Z_RLE to limit match distances to one (run-length
586 encoding). Filtered data consists mostly of small values with a somewhat
587 random distribution. In this case, the compression algorithm is tuned to
588 compress them better. The effect of Z_FILTERED is to force more Huffman
589 coding and less string matching; it is somewhat intermediate between
590 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
591 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
592 strategy parameter only affects the compression ratio but not the
593 correctness of the compressed output even if it is not set appropriately.
594 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
595 decoder for special applications.
596
597 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
598 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
599 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
600 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
601 set to null if there is no error message. deflateInit2 does not perform any
602 compression: this will be done by deflate().
603 */
604
605 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
606 const Bytef *dictionary,
607 uInt dictLength));
608 /*
609 Initializes the compression dictionary from the given byte sequence
610 without producing any compressed output. When using the zlib format, this
611 function must be called immediately after deflateInit, deflateInit2 or
612 deflateReset, and before any call of deflate. When doing raw deflate, this
613 function must be called either before any call of deflate, or immediately
614 after the completion of a deflate block, i.e. after all input has been
615 consumed and all output has been delivered when using any of the flush
616 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The
617 compressor and decompressor must use exactly the same dictionary (see
618 inflateSetDictionary).
619
620 The dictionary should consist of strings (byte sequences) that are likely
621 to be encountered later in the data to be compressed, with the most commonly
622 used strings preferably put towards the end of the dictionary. Using a
623 dictionary is most useful when the data to be compressed is short and can be
624 predicted with good accuracy; the data can then be compressed better than
625 with the default empty dictionary.
626
627 Depending on the size of the compression data structures selected by
628 deflateInit or deflateInit2, a part of the dictionary may in effect be
629 discarded, for example if the dictionary is larger than the window size
630 provided in deflateInit or deflateInit2. Thus the strings most likely to be
631 useful should be put at the end of the dictionary, not at the front. In
632 addition, the current implementation of deflate will use at most the window
633 size minus 262 bytes of the provided dictionary.
634
635 Upon return of this function, strm->adler is set to the adler32 value
636 of the dictionary; the decompressor may later use this value to determine
637 which dictionary has been used by the compressor. (The adler32 value
638 applies to the whole dictionary even if only a subset of the dictionary is
639 actually used by the compressor.) If a raw deflate was requested, then the
640 adler32 value is not computed and strm->adler is not set.
641
642 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
643 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
644 inconsistent (for example if deflate has already been called for this stream
645 or if not at a block boundary for raw deflate). deflateSetDictionary does
646 not perform any compression: this will be done by deflate().
647 */
648
649 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
650 z_streamp source));
651 /*
652 Sets the destination stream as a complete copy of the source stream.
653
654 This function can be useful when several compression strategies will be
655 tried, for example when there are several ways of pre-processing the input
656 data with a filter. The streams that will be discarded should then be freed
657 by calling deflateEnd. Note that deflateCopy duplicates the internal
658 compression state which can be quite large, so this strategy is slow and can
659 consume lots of memory.
660
661 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
662 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
663 (such as zalloc being Z_NULL). msg is left unchanged in both source and
664 destination.
665 */
666
667 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
668 /*
669 This function is equivalent to deflateEnd followed by deflateInit,
670 but does not free and reallocate all the internal compression state. The
671 stream will keep the same compression level and any other attributes that
672 may have been set by deflateInit2.
673
674 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
675 stream state was inconsistent (such as zalloc or state being Z_NULL).
676 */
677
678 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
679 int level,
680 int strategy));
681 /*
682 Dynamically update the compression level and compression strategy. The
683 interpretation of level and strategy is as in deflateInit2. This can be
684 used to switch between compression and straight copy of the input data, or
685 to switch to a different kind of input data requiring a different strategy.
686 If the compression level is changed, the input available so far is
687 compressed with the old level (and may be flushed); the new level will take
688 effect only at the next call of deflate().
689
690 Before the call of deflateParams, the stream state must be set as for
691 a call of deflate(), since the currently available input may have to be
692 compressed and flushed. In particular, strm->avail_out must be non-zero.
693
694 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
695 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
696 strm->avail_out was zero.
697 */
698
699 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
700 int good_length,
701 int max_lazy,
702 int nice_length,
703 int max_chain));
704 /*
705 Fine tune deflate's internal compression parameters. This should only be
706 used by someone who understands the algorithm used by zlib's deflate for
707 searching for the best matching string, and even then only by the most
708 fanatic optimizer trying to squeeze out the last compressed bit for their
709 specific input data. Read the deflate.c source code for the meaning of the
710 max_lazy, good_length, nice_length, and max_chain parameters.
711
712 deflateTune() can be called after deflateInit() or deflateInit2(), and
713 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
714 */
715
716 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
717 uLong sourceLen));
718 /*
719 deflateBound() returns an upper bound on the compressed size after
720 deflation of sourceLen bytes. It must be called after deflateInit() or
721 deflateInit2(), and after deflateSetHeader(), if used. This would be used
722 to allocate an output buffer for deflation in a single pass, and so would be
723 called before deflate(). If that first deflate() call is provided the
724 sourceLen input bytes, an output buffer allocated to the size returned by
725 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
726 to return Z_STREAM_END. Note that it is possible for the compressed size to
727 be larger than the value returned by deflateBound() if flush options other
728 than Z_FINISH or Z_NO_FLUSH are used.
729 */
730
731 ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
732 unsigned *pending,
733 int *bits));
734 /*
735 deflatePending() returns the number of bytes and bits of output that have
736 been generated, but not yet provided in the available output. The bytes not
737 provided would be due to the available output space having being consumed.
738 The number of bits of output not provided are between 0 and 7, where they
739 await more bits to join them in order to fill out a full byte. If pending
740 or bits are Z_NULL, then those values are not set.
741
742 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
743 stream state was inconsistent.
744 */
745
746 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
747 int bits,
748 int value));
749 /*
750 deflatePrime() inserts bits in the deflate output stream. The intent
751 is that this function is used to start off the deflate output with the bits
752 leftover from a previous deflate stream when appending to it. As such, this
753 function can only be used for raw deflate, and must be used before the first
754 deflate() call after a deflateInit2() or deflateReset(). bits must be less
755 than or equal to 16, and that many of the least significant bits of value
756 will be inserted in the output.
757
758 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
759 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
760 source stream state was inconsistent.
761 */
762
763 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
764 gz_headerp head));
765 /*
766 deflateSetHeader() provides gzip header information for when a gzip
767 stream is requested by deflateInit2(). deflateSetHeader() may be called
768 after deflateInit2() or deflateReset() and before the first call of
769 deflate(). The text, time, os, extra field, name, and comment information
770 in the provided gz_header structure are written to the gzip header (xflag is
771 ignored -- the extra flags are set according to the compression level). The
772 caller must assure that, if not Z_NULL, name and comment are terminated with
773 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
774 available there. If hcrc is true, a gzip header crc is included. Note that
775 the current versions of the command-line version of gzip (up through version
776 1.3.x) do not support header crc's, and will report that it is a "multi-part
777 gzip file" and give up.
778
779 If deflateSetHeader is not used, the default gzip header has text false,
780 the time set to zero, and os set to 255, with no extra, name, or comment
781 fields. The gzip header is returned to the default state by deflateReset().
782
783 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
784 stream state was inconsistent.
785 */
786
787 /*
788 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
789 int windowBits));
790
791 This is another version of inflateInit with an extra parameter. The
792 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
793 before by the caller.
794
795 The windowBits parameter is the base two logarithm of the maximum window
796 size (the size of the history buffer). It should be in the range 8..15 for
797 this version of the library. The default value is 15 if inflateInit is used
798 instead. windowBits must be greater than or equal to the windowBits value
799 provided to deflateInit2() while compressing, or it must be equal to 15 if
800 deflateInit2() was not used. If a compressed stream with a larger window
801 size is given as input, inflate() will return with the error code
802 Z_DATA_ERROR instead of trying to allocate a larger window.
803
804 windowBits can also be zero to request that inflate use the window size in
805 the zlib header of the compressed stream.
806
807 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
808 determines the window size. inflate() will then process raw deflate data,
809 not looking for a zlib or gzip header, not generating a check value, and not
810 looking for any check values for comparison at the end of the stream. This
811 is for use with other formats that use the deflate compressed data format
812 such as zip. Those formats provide their own check values. If a custom
813 format is developed using the raw deflate format for compressed data, it is
814 recommended that a check value such as an adler32 or a crc32 be applied to
815 the uncompressed data as is done in the zlib, gzip, and zip formats. For
816 most applications, the zlib format should be used as is. Note that comments
817 above on the use in deflateInit2() applies to the magnitude of windowBits.
818
819 windowBits can also be greater than 15 for optional gzip decoding. Add
820 32 to windowBits to enable zlib and gzip decoding with automatic header
821 detection, or add 16 to decode only the gzip format (the zlib format will
822 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
823 crc32 instead of an adler32.
824
825 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
826 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
827 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
828 invalid, such as a null pointer to the structure. msg is set to null if
829 there is no error message. inflateInit2 does not perform any decompression
830 apart from possibly reading the zlib header if present: actual decompression
831 will be done by inflate(). (So next_in and avail_in may be modified, but
832 next_out and avail_out are unused and unchanged.) The current implementation
833 of inflateInit2() does not process any header information -- that is
834 deferred until inflate() is called.
835 */
836
837 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
838 const Bytef *dictionary,
839 uInt dictLength));
840 /*
841 Initializes the decompression dictionary from the given uncompressed byte
842 sequence. This function must be called immediately after a call of inflate,
843 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
844 can be determined from the adler32 value returned by that call of inflate.
845 The compressor and decompressor must use exactly the same dictionary (see
846 deflateSetDictionary). For raw inflate, this function can be called at any
847 time to set the dictionary. If the provided dictionary is smaller than the
848 window and there is already data in the window, then the provided dictionary
849 will amend what's there. The application must insure that the dictionary
850 that was used for compression is provided.
851
852 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
853 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
854 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
855 expected one (incorrect adler32 value). inflateSetDictionary does not
856 perform any decompression: this will be done by subsequent calls of
857 inflate().
858 */
859
860 ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
861 Bytef *dictionary,
862 uInt *dictLength));
863 /*
864 Returns the sliding dictionary being maintained by inflate. dictLength is
865 set to the number of bytes in the dictionary, and that many bytes are copied
866 to dictionary. dictionary must have enough space, where 32768 bytes is
867 always enough. If inflateGetDictionary() is called with dictionary equal to
868 Z_NULL, then only the dictionary length is returned, and nothing is copied.
869 Similary, if dictLength is Z_NULL, then it is not set.
870
871 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
872 stream state is inconsistent.
873 */
874
875 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
876 /*
877 Skips invalid compressed data until a possible full flush point (see above
878 for the description of deflate with Z_FULL_FLUSH) can be found, or until all
879 available input is skipped. No output is provided.
880
881 inflateSync searches for a 00 00 FF FF pattern in the compressed data.
882 All full flush points have this pattern, but not all occurrences of this
883 pattern are full flush points.
884
885 inflateSync returns Z_OK if a possible full flush point has been found,
886 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
887 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
888 In the success case, the application may save the current current value of
889 total_in which indicates where valid compressed data was found. In the
890 error case, the application may repeatedly call inflateSync, providing more
891 input each time, until success or end of the input data.
892 */
893
894 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
895 z_streamp source));
896 /*
897 Sets the destination stream as a complete copy of the source stream.
898
899 This function can be useful when randomly accessing a large stream. The
900 first pass through the stream can periodically record the inflate state,
901 allowing restarting inflate at those points when randomly accessing the
902 stream.
903
904 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
905 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
906 (such as zalloc being Z_NULL). msg is left unchanged in both source and
907 destination.
908 */
909
910 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
911 /*
912 This function is equivalent to inflateEnd followed by inflateInit,
913 but does not free and reallocate all the internal decompression state. The
914 stream will keep attributes that may have been set by inflateInit2.
915
916 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
917 stream state was inconsistent (such as zalloc or state being Z_NULL).
918 */
919
920 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
921 int windowBits));
922 /*
923 This function is the same as inflateReset, but it also permits changing
924 the wrap and window size requests. The windowBits parameter is interpreted
925 the same as it is for inflateInit2.
926
927 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
928 stream state was inconsistent (such as zalloc or state being Z_NULL), or if
929 the windowBits parameter is invalid.
930 */
931
932 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
933 int bits,
934 int value));
935 /*
936 This function inserts bits in the inflate input stream. The intent is
937 that this function is used to start inflating at a bit position in the
938 middle of a byte. The provided bits will be used before any bytes are used
939 from next_in. This function should only be used with raw inflate, and
940 should be used before the first inflate() call after inflateInit2() or
941 inflateReset(). bits must be less than or equal to 16, and that many of the
942 least significant bits of value will be inserted in the input.
943
944 If bits is negative, then the input stream bit buffer is emptied. Then
945 inflatePrime() can be called again to put bits in the buffer. This is used
946 to clear out bits leftover after feeding inflate a block description prior
947 to feeding inflate codes.
948
949 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
950 stream state was inconsistent.
951 */
952
953 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
954 /*
955 This function returns two values, one in the lower 16 bits of the return
956 value, and the other in the remaining upper bits, obtained by shifting the
957 return value down 16 bits. If the upper value is -1 and the lower value is
958 zero, then inflate() is currently decoding information outside of a block.
959 If the upper value is -1 and the lower value is non-zero, then inflate is in
960 the middle of a stored block, with the lower value equaling the number of
961 bytes from the input remaining to copy. If the upper value is not -1, then
962 it is the number of bits back from the current bit position in the input of
963 the code (literal or length/distance pair) currently being processed. In
964 that case the lower value is the number of bytes already emitted for that
965 code.
966
967 A code is being processed if inflate is waiting for more input to complete
968 decoding of the code, or if it has completed decoding but is waiting for
969 more output space to write the literal or match data.
970
971 inflateMark() is used to mark locations in the input data for random
972 access, which may be at bit positions, and to note those cases where the
973 output of a code may span boundaries of random access blocks. The current
974 location in the input stream can be determined from avail_in and data_type
975 as noted in the description for the Z_BLOCK flush parameter for inflate.
976
977 inflateMark returns the value noted above or -1 << 16 if the provided
978 source stream state was inconsistent.
979 */
980
981 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
982 gz_headerp head));
983 /*
984 inflateGetHeader() requests that gzip header information be stored in the
985 provided gz_header structure. inflateGetHeader() may be called after
986 inflateInit2() or inflateReset(), and before the first call of inflate().
987 As inflate() processes the gzip stream, head->done is zero until the header
988 is completed, at which time head->done is set to one. If a zlib stream is
989 being decoded, then head->done is set to -1 to indicate that there will be
990 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
991 used to force inflate() to return immediately after header processing is
992 complete and before any actual data is decompressed.
993
994 The text, time, xflags, and os fields are filled in with the gzip header
995 contents. hcrc is set to true if there is a header CRC. (The header CRC
996 was valid if done is set to one.) If extra is not Z_NULL, then extra_max
997 contains the maximum number of bytes to write to extra. Once done is true,
998 extra_len contains the actual extra field length, and extra contains the
999 extra field, or that field truncated if extra_max is less than extra_len.
1000 If name is not Z_NULL, then up to name_max characters are written there,
1001 terminated with a zero unless the length is greater than name_max. If
1002 comment is not Z_NULL, then up to comm_max characters are written there,
1003 terminated with a zero unless the length is greater than comm_max. When any
1004 of extra, name, or comment are not Z_NULL and the respective field is not
1005 present in the header, then that field is set to Z_NULL to signal its
1006 absence. This allows the use of deflateSetHeader() with the returned
1007 structure to duplicate the header. However if those fields are set to
1008 allocated memory, then the application will need to save those pointers
1009 elsewhere so that they can be eventually freed.
1010
1011 If inflateGetHeader is not used, then the header information is simply
1012 discarded. The header is always checked for validity, including the header
1013 CRC if present. inflateReset() will reset the process to discard the header
1014 information. The application would need to call inflateGetHeader() again to
1015 retrieve the header from the next gzip stream.
1016
1017 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
1018 stream state was inconsistent.
1019 */
1020
1021 /*
1022 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
1023 unsigned char FAR *window));
1024
1025 Initialize the internal stream state for decompression using inflateBack()
1026 calls. The fields zalloc, zfree and opaque in strm must be initialized
1027 before the call. If zalloc and zfree are Z_NULL, then the default library-
1028 derived memory allocation routines are used. windowBits is the base two
1029 logarithm of the window size, in the range 8..15. window is a caller
1030 supplied buffer of that size. Except for special applications where it is
1031 assured that deflate was used with small window sizes, windowBits must be 15
1032 and a 32K byte window must be supplied to be able to decompress general
1033 deflate streams.
1034
1035 See inflateBack() for the usage of these routines.
1036
1037 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
1038 the parameters are invalid, Z_MEM_ERROR if the internal state could not be
1039 allocated, or Z_VERSION_ERROR if the version of the library does not match
1040 the version of the header file.
1041 */
1042
1043 typedef unsigned (*in_func) OF((void FAR *,
1044 z_const unsigned char FAR * FAR *));
1045 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
1046
1047 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
1048 in_func in, void FAR *in_desc,
1049 out_func out, void FAR *out_desc));
1050 /*
1051 inflateBack() does a raw inflate with a single call using a call-back
1052 interface for input and output. This is potentially more efficient than
1053 inflate() for file i/o applications, in that it avoids copying between the
1054 output and the sliding window by simply making the window itself the output
1055 buffer. inflate() can be faster on modern CPUs when used with large
1056 buffers. inflateBack() trusts the application to not change the output
1057 buffer passed by the output function, at least until inflateBack() returns.
1058
1059 inflateBackInit() must be called first to allocate the internal state
1060 and to initialize the state with the user-provided window buffer.
1061 inflateBack() may then be used multiple times to inflate a complete, raw
1062 deflate stream with each call. inflateBackEnd() is then called to free the
1063 allocated state.
1064
1065 A raw deflate stream is one with no zlib or gzip header or trailer.
1066 This routine would normally be used in a utility that reads zip or gzip
1067 files and writes out uncompressed files. The utility would decode the
1068 header and process the trailer on its own, hence this routine expects only
1069 the raw deflate stream to decompress. This is different from the normal
1070 behavior of inflate(), which expects either a zlib or gzip header and
1071 trailer around the deflate stream.
1072
1073 inflateBack() uses two subroutines supplied by the caller that are then
1074 called by inflateBack() for input and output. inflateBack() calls those
1075 routines until it reads a complete deflate stream and writes out all of the
1076 uncompressed data, or until it encounters an error. The function's
1077 parameters and return types are defined above in the in_func and out_func
1078 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
1079 number of bytes of provided input, and a pointer to that input in buf. If
1080 there is no input available, in() must return zero--buf is ignored in that
1081 case--and inflateBack() will return a buffer error. inflateBack() will call
1082 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
1083 should return zero on success, or non-zero on failure. If out() returns
1084 non-zero, inflateBack() will return with an error. Neither in() nor out()
1085 are permitted to change the contents of the window provided to
1086 inflateBackInit(), which is also the buffer that out() uses to write from.
1087 The length written by out() will be at most the window size. Any non-zero
1088 amount of input may be provided by in().
1089
1090 For convenience, inflateBack() can be provided input on the first call by
1091 setting strm->next_in and strm->avail_in. If that input is exhausted, then
1092 in() will be called. Therefore strm->next_in must be initialized before
1093 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
1094 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
1095 must also be initialized, and then if strm->avail_in is not zero, input will
1096 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
1097
1098 The in_desc and out_desc parameters of inflateBack() is passed as the
1099 first parameter of in() and out() respectively when they are called. These
1100 descriptors can be optionally used to pass any information that the caller-
1101 supplied in() and out() functions need to do their job.
1102
1103 On return, inflateBack() will set strm->next_in and strm->avail_in to
1104 pass back any unused input that was provided by the last in() call. The
1105 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
1106 if in() or out() returned an error, Z_DATA_ERROR if there was a format error
1107 in the deflate stream (in which case strm->msg is set to indicate the nature
1108 of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
1109 In the case of Z_BUF_ERROR, an input or output error can be distinguished
1110 using strm->next_in which will be Z_NULL only if in() returned an error. If
1111 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1112 non-zero. (in() will always be called before out(), so strm->next_in is
1113 assured to be defined if out() returns non-zero.) Note that inflateBack()
1114 cannot return Z_OK.
1115 */
1116
1117 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
1118 /*
1119 All memory allocated by inflateBackInit() is freed.
1120
1121 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
1122 state was inconsistent.
1123 */
1124
1125 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
1126 /* Return flags indicating compile-time options.
1127
1128 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1129 1.0: size of uInt
1130 3.2: size of uLong
1131 5.4: size of voidpf (pointer)
1132 7.6: size of z_off_t
1133
1134 Compiler, assembler, and debug options:
1135 8: DEBUG
1136 9: ASMV or ASMINF -- use ASM code
1137 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1138 11: 0 (reserved)
1139
1140 One-time table building (smaller code, but not thread-safe if true):
1141 12: BUILDFIXED -- build static block decoding tables when needed
1142 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1143 14,15: 0 (reserved)
1144
1145 Library content (indicates missing functionality):
1146 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1147 deflate code when not needed)
1148 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1149 and decode gzip streams (to avoid linking crc code)
1150 18-19: 0 (reserved)
1151
1152 Operation variations (changes in library functionality):
1153 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1154 21: FASTEST -- deflate algorithm with only one, lowest compression level
1155 22,23: 0 (reserved)
1156
1157 The sprintf variant used by gzprintf (zero is best):
1158 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1159 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1160 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1161
1162 Remainder:
1163 27-31: 0 (reserved)
1164 */
1165
1166 #ifndef Z_SOLO
1167
1168 /* utility functions */
1169
1170 /*
1171 The following utility functions are implemented on top of the basic
1172 stream-oriented functions. To simplify the interface, some default options
1173 are assumed (compression level and memory usage, standard memory allocation
1174 functions). The source code of these utility functions can be modified if
1175 you need special options.
1176 */
1177
1178 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
1179 const Bytef *source, uLong sourceLen));
1180 /*
1181 Compresses the source buffer into the destination buffer. sourceLen is
1182 the byte length of the source buffer. Upon entry, destLen is the total size
1183 of the destination buffer, which must be at least the value returned by
1184 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1185 compressed buffer.
1186
1187 compress returns Z_OK if success, Z_MEM_ERROR if there was not
1188 enough memory, Z_BUF_ERROR if there was not enough room in the output
1189 buffer.
1190 */
1191
1192 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
1193 const Bytef *source, uLong sourceLen,
1194 int level));
1195 /*
1196 Compresses the source buffer into the destination buffer. The level
1197 parameter has the same meaning as in deflateInit. sourceLen is the byte
1198 length of the source buffer. Upon entry, destLen is the total size of the
1199 destination buffer, which must be at least the value returned by
1200 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1201 compressed buffer.
1202
1203 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1204 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1205 Z_STREAM_ERROR if the level parameter is invalid.
1206 */
1207
1208 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1209 /*
1210 compressBound() returns an upper bound on the compressed size after
1211 compress() or compress2() on sourceLen bytes. It would be used before a
1212 compress() or compress2() call to allocate the destination buffer.
1213 */
1214
1215 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
1216 const Bytef *source, uLong sourceLen));
1217 /*
1218 Decompresses the source buffer into the destination buffer. sourceLen is
1219 the byte length of the source buffer. Upon entry, destLen is the total size
1220 of the destination buffer, which must be large enough to hold the entire
1221 uncompressed data. (The size of the uncompressed data must have been saved
1222 previously by the compressor and transmitted to the decompressor by some
1223 mechanism outside the scope of this compression library.) Upon exit, destLen
1224 is the actual size of the uncompressed buffer.
1225
1226 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1227 enough memory, Z_BUF_ERROR if there was not enough room in the output
1228 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In
1229 the case where there is not enough room, uncompress() will fill the output
1230 buffer with the uncompressed data up to that point.
1231 */
1232
1233 /* gzip file access functions */
1234
1235 /*
1236 This library supports reading and writing files in gzip (.gz) format with
1237 an interface similar to that of stdio, using the functions that start with
1238 "gz". The gzip format is different from the zlib format. gzip is a gzip
1239 wrapper, documented in RFC 1952, wrapped around a deflate stream.
1240 */
1241
1242 typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
1243
1244 /*
1245 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1246
1247 Opens a gzip (.gz) file for reading or writing. The mode parameter is as
1248 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
1249 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
1250 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
1251 for fixed code compression as in "wb9F". (See the description of
1252 deflateInit2 for more information about the strategy parameter.) 'T' will
1253 request transparent writing or appending with no compression and not using
1254 the gzip format.
1255
1256 "a" can be used instead of "w" to request that the gzip stream that will
1257 be written be appended to the file. "+" will result in an error, since
1258 reading and writing to the same gzip file is not supported. The addition of
1259 "x" when writing will create the file exclusively, which fails if the file
1260 already exists. On systems that support it, the addition of "e" when
1261 reading or writing will set the flag to close the file on an execve() call.
1262
1263 These functions, as well as gzip, will read and decode a sequence of gzip
1264 streams in a file. The append function of gzopen() can be used to create
1265 such a file. (Also see gzflush() for another way to do this.) When
1266 appending, gzopen does not test whether the file begins with a gzip stream,
1267 nor does it look for the end of the gzip streams to begin appending. gzopen
1268 will simply append a gzip stream to the existing file.
1269
1270 gzopen can be used to read a file which is not in gzip format; in this
1271 case gzread will directly read from the file without decompression. When
1272 reading, this will be detected automatically by looking for the magic two-
1273 byte gzip header.
1274
1275 gzopen returns NULL if the file could not be opened, if there was
1276 insufficient memory to allocate the gzFile state, or if an invalid mode was
1277 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
1278 errno can be checked to determine if the reason gzopen failed was that the
1279 file could not be opened.
1280 */
1281
1282 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1283 /*
1284 gzdopen associates a gzFile with the file descriptor fd. File descriptors
1285 are obtained from calls like open, dup, creat, pipe or fileno (if the file
1286 has been previously opened with fopen). The mode parameter is as in gzopen.
1287
1288 The next call of gzclose on the returned gzFile will also close the file
1289 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
1290 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
1291 mode);. The duplicated descriptor should be saved to avoid a leak, since
1292 gzdopen does not close fd if it fails. If you are using fileno() to get the
1293 file descriptor from a FILE *, then you will have to use dup() to avoid
1294 double-close()ing the file descriptor. Both gzclose() and fclose() will
1295 close the associated file descriptor, so they need to have different file
1296 descriptors.
1297
1298 gzdopen returns NULL if there was insufficient memory to allocate the
1299 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
1300 provided, or '+' was provided), or if fd is -1. The file descriptor is not
1301 used until the next gz* read, write, seek, or close operation, so gzdopen
1302 will not detect if fd is invalid (unless fd is -1).
1303 */
1304
1305 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
1306 /*
1307 Set the internal buffer size used by this library's functions. The
1308 default buffer size is 8192 bytes. This function must be called after
1309 gzopen() or gzdopen(), and before any other calls that read or write the
1310 file. The buffer memory allocation is always deferred to the first read or
1311 write. Two buffers are allocated, either both of the specified size when
1312 writing, or one of the specified size and the other twice that size when
1313 reading. A larger buffer size of, for example, 64K or 128K bytes will
1314 noticeably increase the speed of decompression (reading).
1315
1316 The new buffer size also affects the maximum length for gzprintf().
1317
1318 gzbuffer() returns 0 on success, or -1 on failure, such as being called
1319 too late.
1320 */
1321
1322 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1323 /*
1324 Dynamically update the compression level or strategy. See the description
1325 of deflateInit2 for the meaning of these parameters.
1326
1327 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
1328 opened for writing.
1329 */
1330
1331 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1332 /*
1333 Reads the given number of uncompressed bytes from the compressed file. If
1334 the input file is not in gzip format, gzread copies the given number of
1335 bytes into the buffer directly from the file.
1336
1337 After reaching the end of a gzip stream in the input, gzread will continue
1338 to read, looking for another gzip stream. Any number of gzip streams may be
1339 concatenated in the input file, and will all be decompressed by gzread().
1340 If something other than a gzip stream is encountered after a gzip stream,
1341 that remaining trailing garbage is ignored (and no error is returned).
1342
1343 gzread can be used to read a gzip file that is being concurrently written.
1344 Upon reaching the end of the input, gzread will return with the available
1345 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
1346 gzclearerr can be used to clear the end of file indicator in order to permit
1347 gzread to be tried again. Z_OK indicates that a gzip stream was completed
1348 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the
1349 middle of a gzip stream. Note that gzread does not return -1 in the event
1350 of an incomplete gzip stream. This error is deferred until gzclose(), which
1351 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
1352 stream. Alternatively, gzerror can be used before gzclose to detect this
1353 case.
1354
1355 gzread returns the number of uncompressed bytes actually read, less than
1356 len for end of file, or -1 for error.
1357 */
1358
1359 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
1360 voidpc buf, unsigned len));
1361 /*
1362 Writes the given number of uncompressed bytes into the compressed file.
1363 gzwrite returns the number of uncompressed bytes written or 0 in case of
1364 error.
1365 */
1366
1367 ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
1368 /*
1369 Converts, formats, and writes the arguments to the compressed file under
1370 control of the format string, as in fprintf. gzprintf returns the number of
1371 uncompressed bytes actually written, or 0 in case of error. The number of
1372 uncompressed bytes written is limited to 8191, or one less than the buffer
1373 size given to gzbuffer(). The caller should assure that this limit is not
1374 exceeded. If it is exceeded, then gzprintf() will return an error (0) with
1375 nothing written. In this case, there may also be a buffer overflow with
1376 unpredictable consequences, which is possible only if zlib was compiled with
1377 the insecure functions sprintf() or vsprintf() because the secure snprintf()
1378 or vsnprintf() functions were not available. This can be determined using
1379 zlibCompileFlags().
1380 */
1381
1382 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1383 /*
1384 Writes the given null-terminated string to the compressed file, excluding
1385 the terminating null character.
1386
1387 gzputs returns the number of characters written, or -1 in case of error.
1388 */
1389
1390 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1391 /*
1392 Reads bytes from the compressed file until len-1 characters are read, or a
1393 newline character is read and transferred to buf, or an end-of-file
1394 condition is encountered. If any characters are read or if len == 1, the
1395 string is terminated with a null character. If no characters are read due
1396 to an end-of-file or len < 1, then the buffer is left untouched.
1397
1398 gzgets returns buf which is a null-terminated string, or it returns NULL
1399 for end-of-file or in case of error. If there was an error, the contents at
1400 buf are indeterminate.
1401 */
1402
1403 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1404 /*
1405 Writes c, converted to an unsigned char, into the compressed file. gzputc
1406 returns the value that was written, or -1 in case of error.
1407 */
1408
1409 ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1410 /*
1411 Reads one byte from the compressed file. gzgetc returns this byte or -1
1412 in case of end of file or error. This is implemented as a macro for speed.
1413 As such, it does not do all of the checking the other functions do. I.e.
1414 it does not check to see if file is NULL, nor whether the structure file
1415 points to has been clobbered or not.
1416 */
1417
1418 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1419 /*
1420 Push one character back onto the stream to be read as the first character
1421 on the next read. At least one character of push-back is allowed.
1422 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
1423 fail if c is -1, and may fail if a character has been pushed but not read
1424 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
1425 output buffer size of pushed characters is allowed. (See gzbuffer above.)
1426 The pushed character will be discarded if the stream is repositioned with
1427 gzseek() or gzrewind().
1428 */
1429
1430 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1431 /*
1432 Flushes all pending output into the compressed file. The parameter flush
1433 is as in the deflate() function. The return value is the zlib error number
1434 (see function gzerror below). gzflush is only permitted when writing.
1435
1436 If the flush parameter is Z_FINISH, the remaining data is written and the
1437 gzip stream is completed in the output. If gzwrite() is called again, a new
1438 gzip stream will be started in the output. gzread() is able to read such
1439 concatented gzip streams.
1440
1441 gzflush should be called only when strictly necessary because it will
1442 degrade compression if called too often.
1443 */
1444
1445 /*
1446 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1447 z_off_t offset, int whence));
1448
1449 Sets the starting position for the next gzread or gzwrite on the given
1450 compressed file. The offset represents a number of bytes in the
1451 uncompressed data stream. The whence parameter is defined as in lseek(2);
1452 the value SEEK_END is not supported.
1453
1454 If the file is opened for reading, this function is emulated but can be
1455 extremely slow. If the file is opened for writing, only forward seeks are
1456 supported; gzseek then compresses a sequence of zeroes up to the new
1457 starting position.
1458
1459 gzseek returns the resulting offset location as measured in bytes from
1460 the beginning of the uncompressed stream, or -1 in case of error, in
1461 particular if the file is opened for writing and the new starting position
1462 would be before the current position.
1463 */
1464
1465 ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
1466 /*
1467 Rewinds the given file. This function is supported only for reading.
1468
1469 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1470 */
1471
1472 /*
1473 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1474
1475 Returns the starting position for the next gzread or gzwrite on the given
1476 compressed file. This position represents a number of bytes in the
1477 uncompressed data stream, and is zero when starting, even if appending or
1478 reading a gzip stream from the middle of a file using gzdopen().
1479
1480 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1481 */
1482
1483 /*
1484 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
1485
1486 Returns the current offset in the file being read or written. This offset
1487 includes the count of bytes that precede the gzip stream, for example when
1488 appending or when using gzdopen() for reading. When reading, the offset
1489 does not include as yet unused buffered input. This information can be used
1490 for a progress indicator. On error, gzoffset() returns -1.
1491 */
1492
1493 ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1494 /*
1495 Returns true (1) if the end-of-file indicator has been set while reading,
1496 false (0) otherwise. Note that the end-of-file indicator is set only if the
1497 read tried to go past the end of the input, but came up short. Therefore,
1498 just like feof(), gzeof() may return false even if there is no more data to
1499 read, in the event that the last read request was for the exact number of
1500 bytes remaining in the input file. This will happen if the input file size
1501 is an exact multiple of the buffer size.
1502
1503 If gzeof() returns true, then the read functions will return no more data,
1504 unless the end-of-file indicator is reset by gzclearerr() and the input file
1505 has grown since the previous end of file was detected.
1506 */
1507
1508 ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1509 /*
1510 Returns true (1) if file is being copied directly while reading, or false
1511 (0) if file is a gzip stream being decompressed.
1512
1513 If the input file is empty, gzdirect() will return true, since the input
1514 does not contain a gzip stream.
1515
1516 If gzdirect() is used immediately after gzopen() or gzdopen() it will
1517 cause buffers to be allocated to allow reading the file to determine if it
1518 is a gzip file. Therefore if gzbuffer() is used, it should be called before
1519 gzdirect().
1520
1521 When writing, gzdirect() returns true (1) if transparent writing was
1522 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note:
1523 gzdirect() is not needed when writing. Transparent writing must be
1524 explicitly requested, so the application already knows the answer. When
1525 linking statically, using gzdirect() will include all of the zlib code for
1526 gzip file reading and decompression, which may not be desired.)
1527 */
1528
1529 ZEXTERN int ZEXPORT gzclose OF((gzFile file));
1530 /*
1531 Flushes all pending output if necessary, closes the compressed file and
1532 deallocates the (de)compression state. Note that once file is closed, you
1533 cannot call gzerror with file, since its structures have been deallocated.
1534 gzclose must not be called more than once on the same file, just as free
1535 must not be called more than once on the same allocation.
1536
1537 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
1538 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
1539 last read ended in the middle of a gzip stream, or Z_OK on success.
1540 */
1541
1542 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
1543 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
1544 /*
1545 Same as gzclose(), but gzclose_r() is only for use when reading, and
1546 gzclose_w() is only for use when writing or appending. The advantage to
1547 using these instead of gzclose() is that they avoid linking in zlib
1548 compression or decompression code that is not used when only reading or only
1549 writing respectively. If gzclose() is used, then both compression and
1550 decompression code will be included the application when linking to a static
1551 zlib library.
1552 */
1553
1554 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1555 /*
1556 Returns the error message for the last error which occurred on the given
1557 compressed file. errnum is set to zlib error number. If an error occurred
1558 in the file system and not in the compression library, errnum is set to
1559 Z_ERRNO and the application may consult errno to get the exact error code.
1560
1561 The application must not modify the returned string. Future calls to
1562 this function may invalidate the previously returned string. If file is
1563 closed, then the string previously returned by gzerror will no longer be
1564 available.
1565
1566 gzerror() should be used to distinguish errors from end-of-file for those
1567 functions above that do not distinguish those cases in their return values.
1568 */
1569
1570 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1571 /*
1572 Clears the error and end-of-file flags for file. This is analogous to the
1573 clearerr() function in stdio. This is useful for continuing to read a gzip
1574 file that is being written concurrently.
1575 */
1576
1577 #endif /* !Z_SOLO */
1578
1579 /* checksum functions */
1580
1581 /*
1582 These functions are not related to compression but are exported
1583 anyway because they might be useful in applications using the compression
1584 library.
1585 */
1586
1587 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1588 /*
1589 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1590 return the updated checksum. If buf is Z_NULL, this function returns the
1591 required initial value for the checksum.
1592
1593 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1594 much faster.
1595
1596 Usage example:
1597
1598 uLong adler = adler32(0L, Z_NULL, 0);
1599
1600 while (read_buffer(buffer, length) != EOF) {
1601 adler = adler32(adler, buffer, length);
1602 }
1603 if (adler != original_adler) error();
1604 */
1605
1606 /*
1607 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1608 z_off_t len2));
1609
1610 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
1611 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1612 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
1613 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note
1614 that the z_off_t type (like off_t) is a signed integer. If len2 is
1615 negative, the result has no meaning or utility.
1616 */
1617
1618 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
1619 /*
1620 Update a running CRC-32 with the bytes buf[0..len-1] and return the
1621 updated CRC-32. If buf is Z_NULL, this function returns the required
1622 initial value for the crc. Pre- and post-conditioning (one's complement) is
1623 performed within this function so it shouldn't be done by the application.
1624
1625 Usage example:
1626
1627 uLong crc = crc32(0L, Z_NULL, 0);
1628
1629 while (read_buffer(buffer, length) != EOF) {
1630 crc = crc32(crc, buffer, length);
1631 }
1632 if (crc != original_crc) error();
1633 */
1634
1635 /*
1636 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1637
1638 Combine two CRC-32 check values into one. For two sequences of bytes,
1639 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1640 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1641 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1642 len2.
1643 */
1644
1645
1646 /* various hacks, don't look :) */
1647
1648 /* deflateInit and inflateInit are macros to allow checking the zlib version
1649 * and the compiler's view of z_stream:
1650 */
1651 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1652 const char *version, int stream_size));
1653 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1654 const char *version, int stream_size));
1655 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1656 int windowBits, int memLevel,
1657 int strategy, const char *version,
1658 int stream_size));
1659 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
1660 const char *version, int stream_size));
1661 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1662 unsigned char FAR *window,
1663 const char *version,
1664 int stream_size));
1665 #define deflateInit(strm, level) \
1666 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1667 #define inflateInit(strm) \
1668 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1669 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1670 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1671 (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1672 #define inflateInit2(strm, windowBits) \
1673 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1674 (int)sizeof(z_stream))
1675 #define inflateBackInit(strm, windowBits, window) \
1676 inflateBackInit_((strm), (windowBits), (window), \
1677 ZLIB_VERSION, (int)sizeof(z_stream))
1678
1679 #ifndef Z_SOLO
1680
1681 /* gzgetc() macro and its supporting function and exposed data structure. Note
1682 * that the real internal state is much larger than the exposed structure.
1683 * This abbreviated structure exposes just enough for the gzgetc() macro. The
1684 * user should not mess with these exposed elements, since their names or
1685 * behavior could change in the future, perhaps even capriciously. They can
1686 * only be used by the gzgetc() macro. You have been warned.
1687 */
1688 struct gzFile_s {
1689 unsigned have;
1690 unsigned char *next;
1691 z_off64_t pos;
1692 };
1693 ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */
1694 #ifdef Z_PREFIX_SET
1695 # undef z_gzgetc
1696 # define z_gzgetc(g) \
1697 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
1698 #else
1699 # define gzgetc(g) \
1700 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
1701 #endif
1702
1703 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1704 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
1705 * both are true, the application gets the *64 functions, and the regular
1706 * functions are changed to 64 bits) -- in case these are set on systems
1707 * without large file support, _LFS64_LARGEFILE must also be true
1708 */
1709 #ifdef Z_LARGE64
1710 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1711 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
1712 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
1713 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
1714 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
1715 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
1716 #endif
1717
1718 #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
1719 # ifdef Z_PREFIX_SET
1720 # define z_gzopen z_gzopen64
1721 # define z_gzseek z_gzseek64
1722 # define z_gztell z_gztell64
1723 # define z_gzoffset z_gzoffset64
1724 # define z_adler32_combine z_adler32_combine64
1725 # define z_crc32_combine z_crc32_combine64
1726 # else
1727 # define gzopen gzopen64
1728 # define gzseek gzseek64
1729 # define gztell gztell64
1730 # define gzoffset gzoffset64
1731 # define adler32_combine adler32_combine64
1732 # define crc32_combine crc32_combine64
1733 # endif
1734 # ifndef Z_LARGE64
1735 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1736 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
1737 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
1738 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
1739 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
1740 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
1741 # endif
1742 #else
1743 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
1744 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
1745 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
1746 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
1747 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1748 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1749 #endif
1750
1751 #else /* Z_SOLO */
1752
1753 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1754 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1755
1756 #endif /* !Z_SOLO */
1757
1758 /* hack for buggy compilers */
1759 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1760 struct internal_state {int dummy;};
1761 #endif
1762
1763 /* undocumented functions */
1764 ZEXTERN const char * ZEXPORT zError OF((int));
1765 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
1766 ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void));
1767 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
1768 ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp));
1769 ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp));
1770 #if defined(_WIN32) && !defined(Z_SOLO)
1771 ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path,
1772 const char *mode));
1773 #endif
1774 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
1775 # ifndef Z_SOLO
1776 ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file,
1777 const char *format,
1778 va_list va));
1779 # endif
1780 #endif
1781
1782 #ifdef __cplusplus
1783 }
1784 #endif
1785
1786 #endif /* ZLIB_H */
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