lemon-project-template-glpk
comparison deps/glpk/src/zlib/zlib.h @ 9:33de93886c88
Import GLPK 4.47
author | Alpar Juttner <alpar@cs.elte.hu> |
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date | Sun, 06 Nov 2011 20:59:10 +0100 |
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1 /* zlib.h -- interface of the 'zlib' general purpose compression library | |
2 version 1.2.5, April 19th, 2010 | |
3 | |
4 Copyright (C) 1995-2010 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://www.ietf.org/rfc/rfc1950.txt | |
28 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). | |
29 */ | |
30 | |
31 #ifndef ZLIB_H | |
32 #define ZLIB_H | |
33 | |
34 #include "zconf.h" | |
35 | |
36 #ifdef __cplusplus | |
37 extern "C" { | |
38 #endif | |
39 | |
40 #define ZLIB_VERSION "1.2.5" | |
41 #define ZLIB_VERNUM 0x1250 | |
42 #define ZLIB_VER_MAJOR 1 | |
43 #define ZLIB_VER_MINOR 2 | |
44 #define ZLIB_VER_REVISION 5 | |
45 #define ZLIB_VER_SUBREVISION 0 | |
46 | |
47 /* | |
48 The 'zlib' compression library provides in-memory compression and | |
49 decompression functions, including integrity checks of the uncompressed data. | |
50 This version of the library supports only one compression method (deflation) | |
51 but other algorithms will be added later and will have the same stream | |
52 interface. | |
53 | |
54 Compression can be done in a single step if the buffers are large enough, | |
55 or can be done by repeated calls of the compression function. In the latter | |
56 case, the application must provide more input and/or consume the output | |
57 (providing more output space) before each call. | |
58 | |
59 The compressed data format used by default by the in-memory functions is | |
60 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped | |
61 around a deflate stream, which is itself documented in RFC 1951. | |
62 | |
63 The library also supports reading and writing files in gzip (.gz) format | |
64 with an interface similar to that of stdio using the functions that start | |
65 with "gz". The gzip format is different from the zlib format. gzip is a | |
66 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. | |
67 | |
68 This library can optionally read and write gzip streams in memory as well. | |
69 | |
70 The zlib format was designed to be compact and fast for use in memory | |
71 and on communications channels. The gzip format was designed for single- | |
72 file compression on file systems, has a larger header than zlib to maintain | |
73 directory information, and uses a different, slower check method than zlib. | |
74 | |
75 The library does not install any signal handler. The decoder checks | |
76 the consistency of the compressed data, so the library should never crash | |
77 even in case of corrupted input. | |
78 */ | |
79 | |
80 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); | |
81 typedef void (*free_func) OF((voidpf opaque, voidpf address)); | |
82 | |
83 struct internal_state; | |
84 | |
85 typedef struct z_stream_s { | |
86 Bytef *next_in; /* next input byte */ | |
87 uInt avail_in; /* number of bytes available at next_in */ | |
88 uLong total_in; /* total nb of input bytes read so far */ | |
89 | |
90 Bytef *next_out; /* next output byte should be put there */ | |
91 uInt avail_out; /* remaining free space at next_out */ | |
92 uLong total_out; /* total nb of bytes output so far */ | |
93 | |
94 char *msg; /* last error message, NULL if no error */ | |
95 struct internal_state FAR *state; /* not visible by applications */ | |
96 | |
97 alloc_func zalloc; /* used to allocate the internal state */ | |
98 free_func zfree; /* used to free the internal state */ | |
99 voidpf opaque; /* private data object passed to zalloc and zfree */ | |
100 | |
101 int data_type; /* best guess about the data type: binary or text */ | |
102 uLong adler; /* adler32 value of the uncompressed data */ | |
103 uLong reserved; /* reserved for future use */ | |
104 } z_stream; | |
105 | |
106 typedef z_stream FAR *z_streamp; | |
107 | |
108 /* | |
109 gzip header information passed to and from zlib routines. See RFC 1952 | |
110 for more details on the meanings of these fields. | |
111 */ | |
112 typedef struct gz_header_s { | |
113 int text; /* true if compressed data believed to be text */ | |
114 uLong time; /* modification time */ | |
115 int xflags; /* extra flags (not used when writing a gzip file) */ | |
116 int os; /* operating system */ | |
117 Bytef *extra; /* pointer to extra field or Z_NULL if none */ | |
118 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ | |
119 uInt extra_max; /* space at extra (only when reading header) */ | |
120 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ | |
121 uInt name_max; /* space at name (only when reading header) */ | |
122 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ | |
123 uInt comm_max; /* space at comment (only when reading header) */ | |
124 int hcrc; /* true if there was or will be a header crc */ | |
125 int done; /* true when done reading gzip header (not used | |
126 when writing a gzip file) */ | |
127 } gz_header; | |
128 | |
129 typedef gz_header FAR *gz_headerp; | |
130 | |
131 /* | |
132 The application must update next_in and avail_in when avail_in has dropped | |
133 to zero. It must update next_out and avail_out when avail_out has dropped | |
134 to zero. The application must initialize zalloc, zfree and opaque before | |
135 calling the init function. All other fields are set by the compression | |
136 library and must not be updated by the application. | |
137 | |
138 The opaque value provided by the application will be passed as the first | |
139 parameter for calls of zalloc and zfree. This can be useful for custom | |
140 memory management. The compression library attaches no meaning to the | |
141 opaque value. | |
142 | |
143 zalloc must return Z_NULL if there is not enough memory for the object. | |
144 If zlib is used in a multi-threaded application, zalloc and zfree must be | |
145 thread safe. | |
146 | |
147 On 16-bit systems, the functions zalloc and zfree must be able to allocate | |
148 exactly 65536 bytes, but will not be required to allocate more than this if | |
149 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers | |
150 returned by zalloc for objects of exactly 65536 bytes *must* have their | |
151 offset normalized to zero. The default allocation function provided by this | |
152 library ensures this (see zutil.c). To reduce memory requirements and avoid | |
153 any allocation of 64K objects, at the expense of compression ratio, compile | |
154 the library with -DMAX_WBITS=14 (see zconf.h). | |
155 | |
156 The fields total_in and total_out can be used for statistics or progress | |
157 reports. After compression, total_in holds the total size of the | |
158 uncompressed data and may be saved for use in the decompressor (particularly | |
159 if the decompressor wants to decompress everything in a single step). | |
160 */ | |
161 | |
162 /* constants */ | |
163 | |
164 #define Z_NO_FLUSH 0 | |
165 #define Z_PARTIAL_FLUSH 1 | |
166 #define Z_SYNC_FLUSH 2 | |
167 #define Z_FULL_FLUSH 3 | |
168 #define Z_FINISH 4 | |
169 #define Z_BLOCK 5 | |
170 #define Z_TREES 6 | |
171 /* Allowed flush values; see deflate() and inflate() below for details */ | |
172 | |
173 #define Z_OK 0 | |
174 #define Z_STREAM_END 1 | |
175 #define Z_NEED_DICT 2 | |
176 #define Z_ERRNO (-1) | |
177 #define Z_STREAM_ERROR (-2) | |
178 #define Z_DATA_ERROR (-3) | |
179 #define Z_MEM_ERROR (-4) | |
180 #define Z_BUF_ERROR (-5) | |
181 #define Z_VERSION_ERROR (-6) | |
182 /* Return codes for the compression/decompression functions. Negative values | |
183 * are errors, positive values are used for special but normal events. | |
184 */ | |
185 | |
186 #define Z_NO_COMPRESSION 0 | |
187 #define Z_BEST_SPEED 1 | |
188 #define Z_BEST_COMPRESSION 9 | |
189 #define Z_DEFAULT_COMPRESSION (-1) | |
190 /* compression levels */ | |
191 | |
192 #define Z_FILTERED 1 | |
193 #define Z_HUFFMAN_ONLY 2 | |
194 #define Z_RLE 3 | |
195 #define Z_FIXED 4 | |
196 #define Z_DEFAULT_STRATEGY 0 | |
197 /* compression strategy; see deflateInit2() below for details */ | |
198 | |
199 #define Z_BINARY 0 | |
200 #define Z_TEXT 1 | |
201 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ | |
202 #define Z_UNKNOWN 2 | |
203 /* Possible values of the data_type field (though see inflate()) */ | |
204 | |
205 #define Z_DEFLATED 8 | |
206 /* The deflate compression method (the only one supported in this version) */ | |
207 | |
208 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ | |
209 | |
210 #define zlib_version zlibVersion() | |
211 /* for compatibility with versions < 1.0.2 */ | |
212 | |
213 | |
214 /* basic functions */ | |
215 | |
216 ZEXTERN const char * ZEXPORT zlibVersion OF((void)); | |
217 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. | |
218 If the first character differs, the library code actually used is not | |
219 compatible with the zlib.h header file used by the application. This check | |
220 is automatically made by deflateInit and inflateInit. | |
221 */ | |
222 | |
223 /* | |
224 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); | |
225 | |
226 Initializes the internal stream state for compression. The fields | |
227 zalloc, zfree and opaque must be initialized before by the caller. If | |
228 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default | |
229 allocation functions. | |
230 | |
231 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: | |
232 1 gives best speed, 9 gives best compression, 0 gives no compression at all | |
233 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION | |
234 requests a default compromise between speed and compression (currently | |
235 equivalent to level 6). | |
236 | |
237 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
238 memory, Z_STREAM_ERROR if level is not a valid compression level, or | |
239 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible | |
240 with the version assumed by the caller (ZLIB_VERSION). msg is set to null | |
241 if there is no error message. deflateInit does not perform any compression: | |
242 this will be done by deflate(). | |
243 */ | |
244 | |
245 | |
246 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); | |
247 /* | |
248 deflate compresses as much data as possible, and stops when the input | |
249 buffer becomes empty or the output buffer becomes full. It may introduce | |
250 some output latency (reading input without producing any output) except when | |
251 forced to flush. | |
252 | |
253 The detailed semantics are as follows. deflate performs one or both of the | |
254 following actions: | |
255 | |
256 - Compress more input starting at next_in and update next_in and avail_in | |
257 accordingly. If not all input can be processed (because there is not | |
258 enough room in the output buffer), next_in and avail_in are updated and | |
259 processing will resume at this point for the next call of deflate(). | |
260 | |
261 - Provide more output starting at next_out and update next_out and avail_out | |
262 accordingly. This action is forced if the parameter flush is non zero. | |
263 Forcing flush frequently degrades the compression ratio, so this parameter | |
264 should be set only when necessary (in interactive applications). Some | |
265 output may be provided even if flush is not set. | |
266 | |
267 Before the call of deflate(), the application should ensure that at least | |
268 one of the actions is possible, by providing more input and/or consuming more | |
269 output, and updating avail_in or avail_out accordingly; avail_out should | |
270 never be zero before the call. The application can consume the compressed | |
271 output when it wants, for example when the output buffer is full (avail_out | |
272 == 0), or after each call of deflate(). If deflate returns Z_OK and with | |
273 zero avail_out, it must be called again after making room in the output | |
274 buffer because there might be more output pending. | |
275 | |
276 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to | |
277 decide how much data to accumulate before producing output, in order to | |
278 maximize compression. | |
279 | |
280 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is | |
281 flushed to the output buffer and the output is aligned on a byte boundary, so | |
282 that the decompressor can get all input data available so far. (In | |
283 particular avail_in is zero after the call if enough output space has been | |
284 provided before the call.) Flushing may degrade compression for some | |
285 compression algorithms and so it should be used only when necessary. This | |
286 completes the current deflate block and follows it with an empty stored block | |
287 that is three bits plus filler bits to the next byte, followed by four bytes | |
288 (00 00 ff ff). | |
289 | |
290 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the | |
291 output buffer, but the output is not aligned to a byte boundary. All of the | |
292 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. | |
293 This completes the current deflate block and follows it with an empty fixed | |
294 codes block that is 10 bits long. This assures that enough bytes are output | |
295 in order for the decompressor to finish the block before the empty fixed code | |
296 block. | |
297 | |
298 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as | |
299 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to | |
300 seven bits of the current block are held to be written as the next byte after | |
301 the next deflate block is completed. In this case, the decompressor may not | |
302 be provided enough bits at this point in order to complete decompression of | |
303 the data provided so far to the compressor. It may need to wait for the next | |
304 block to be emitted. This is for advanced applications that need to control | |
305 the emission of deflate blocks. | |
306 | |
307 If flush is set to Z_FULL_FLUSH, all output is flushed as with | |
308 Z_SYNC_FLUSH, and the compression state is reset so that decompression can | |
309 restart from this point if previous compressed data has been damaged or if | |
310 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade | |
311 compression. | |
312 | |
313 If deflate returns with avail_out == 0, this function must be called again | |
314 with the same value of the flush parameter and more output space (updated | |
315 avail_out), until the flush is complete (deflate returns with non-zero | |
316 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that | |
317 avail_out is greater than six to avoid repeated flush markers due to | |
318 avail_out == 0 on return. | |
319 | |
320 If the parameter flush is set to Z_FINISH, pending input is processed, | |
321 pending output is flushed and deflate returns with Z_STREAM_END if there was | |
322 enough output space; if deflate returns with Z_OK, this function must be | |
323 called again with Z_FINISH and more output space (updated avail_out) but no | |
324 more input data, until it returns with Z_STREAM_END or an error. After | |
325 deflate has returned Z_STREAM_END, the only possible operations on the stream | |
326 are deflateReset or deflateEnd. | |
327 | |
328 Z_FINISH can be used immediately after deflateInit if all the compression | |
329 is to be done in a single step. In this case, avail_out must be at least the | |
330 value returned by deflateBound (see below). If deflate does not return | |
331 Z_STREAM_END, then it must be called again as described above. | |
332 | |
333 deflate() sets strm->adler to the adler32 checksum of all input read | |
334 so far (that is, total_in bytes). | |
335 | |
336 deflate() may update strm->data_type if it can make a good guess about | |
337 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered | |
338 binary. This field is only for information purposes and does not affect the | |
339 compression algorithm in any manner. | |
340 | |
341 deflate() returns Z_OK if some progress has been made (more input | |
342 processed or more output produced), Z_STREAM_END if all input has been | |
343 consumed and all output has been produced (only when flush is set to | |
344 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example | |
345 if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible | |
346 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not | |
347 fatal, and deflate() can be called again with more input and more output | |
348 space to continue compressing. | |
349 */ | |
350 | |
351 | |
352 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); | |
353 /* | |
354 All dynamically allocated data structures for this stream are freed. | |
355 This function discards any unprocessed input and does not flush any pending | |
356 output. | |
357 | |
358 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the | |
359 stream state was inconsistent, Z_DATA_ERROR if the stream was freed | |
360 prematurely (some input or output was discarded). In the error case, msg | |
361 may be set but then points to a static string (which must not be | |
362 deallocated). | |
363 */ | |
364 | |
365 | |
366 /* | |
367 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); | |
368 | |
369 Initializes the internal stream state for decompression. The fields | |
370 next_in, avail_in, zalloc, zfree and opaque must be initialized before by | |
371 the caller. If next_in is not Z_NULL and avail_in is large enough (the | |
372 exact value depends on the compression method), inflateInit determines the | |
373 compression method from the zlib header and allocates all data structures | |
374 accordingly; otherwise the allocation will be deferred to the first call of | |
375 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to | |
376 use default allocation functions. | |
377 | |
378 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
379 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the | |
380 version assumed by the caller, or Z_STREAM_ERROR if the parameters are | |
381 invalid, such as a null pointer to the structure. msg is set to null if | |
382 there is no error message. inflateInit does not perform any decompression | |
383 apart from possibly reading the zlib header if present: actual decompression | |
384 will be done by inflate(). (So next_in and avail_in may be modified, but | |
385 next_out and avail_out are unused and unchanged.) The current implementation | |
386 of inflateInit() does not process any header information -- that is deferred | |
387 until inflate() is called. | |
388 */ | |
389 | |
390 | |
391 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); | |
392 /* | |
393 inflate decompresses as much data as possible, and stops when the input | |
394 buffer becomes empty or the output buffer becomes full. It may introduce | |
395 some output latency (reading input without producing any output) except when | |
396 forced to flush. | |
397 | |
398 The detailed semantics are as follows. inflate performs one or both of the | |
399 following actions: | |
400 | |
401 - Decompress more input starting at next_in and update next_in and avail_in | |
402 accordingly. If not all input can be processed (because there is not | |
403 enough room in the output buffer), next_in is updated and processing will | |
404 resume at this point for the next call of inflate(). | |
405 | |
406 - Provide more output starting at next_out and update next_out and avail_out | |
407 accordingly. inflate() provides as much output as possible, until there is | |
408 no more input data or no more space in the output buffer (see below about | |
409 the flush parameter). | |
410 | |
411 Before the call of inflate(), the application should ensure that at least | |
412 one of the actions is possible, by providing more input and/or consuming more | |
413 output, and updating the next_* and avail_* values accordingly. The | |
414 application can consume the uncompressed output when it wants, for example | |
415 when the output buffer is full (avail_out == 0), or after each call of | |
416 inflate(). If inflate returns Z_OK and with zero avail_out, it must be | |
417 called again after making room in the output buffer because there might be | |
418 more output pending. | |
419 | |
420 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, | |
421 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much | |
422 output as possible to the output buffer. Z_BLOCK requests that inflate() | |
423 stop if and when it gets to the next deflate block boundary. When decoding | |
424 the zlib or gzip format, this will cause inflate() to return immediately | |
425 after the header and before the first block. When doing a raw inflate, | |
426 inflate() will go ahead and process the first block, and will return when it | |
427 gets to the end of that block, or when it runs out of data. | |
428 | |
429 The Z_BLOCK option assists in appending to or combining deflate streams. | |
430 Also to assist in this, on return inflate() will set strm->data_type to the | |
431 number of unused bits in the last byte taken from strm->next_in, plus 64 if | |
432 inflate() is currently decoding the last block in the deflate stream, plus | |
433 128 if inflate() returned immediately after decoding an end-of-block code or | |
434 decoding the complete header up to just before the first byte of the deflate | |
435 stream. The end-of-block will not be indicated until all of the uncompressed | |
436 data from that block has been written to strm->next_out. The number of | |
437 unused bits may in general be greater than seven, except when bit 7 of | |
438 data_type is set, in which case the number of unused bits will be less than | |
439 eight. data_type is set as noted here every time inflate() returns for all | |
440 flush options, and so can be used to determine the amount of currently | |
441 consumed input in bits. | |
442 | |
443 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the | |
444 end of each deflate block header is reached, before any actual data in that | |
445 block is decoded. This allows the caller to determine the length of the | |
446 deflate block header for later use in random access within a deflate block. | |
447 256 is added to the value of strm->data_type when inflate() returns | |
448 immediately after reaching the end of the deflate block header. | |
449 | |
450 inflate() should normally be called until it returns Z_STREAM_END or an | |
451 error. However if all decompression is to be performed in a single step (a | |
452 single call of inflate), the parameter flush should be set to Z_FINISH. In | |
453 this case all pending input is processed and all pending output is flushed; | |
454 avail_out must be large enough to hold all the uncompressed data. (The size | |
455 of the uncompressed data may have been saved by the compressor for this | |
456 purpose.) The next operation on this stream must be inflateEnd to deallocate | |
457 the decompression state. The use of Z_FINISH is never required, but can be | |
458 used to inform inflate that a faster approach may be used for the single | |
459 inflate() call. | |
460 | |
461 In this implementation, inflate() always flushes as much output as | |
462 possible to the output buffer, and always uses the faster approach on the | |
463 first call. So the only effect of the flush parameter in this implementation | |
464 is on the return value of inflate(), as noted below, or when it returns early | |
465 because Z_BLOCK or Z_TREES is used. | |
466 | |
467 If a preset dictionary is needed after this call (see inflateSetDictionary | |
468 below), inflate sets strm->adler to the adler32 checksum of the dictionary | |
469 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets | |
470 strm->adler to the adler32 checksum of all output produced so far (that is, | |
471 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described | |
472 below. At the end of the stream, inflate() checks that its computed adler32 | |
473 checksum is equal to that saved by the compressor and returns Z_STREAM_END | |
474 only if the checksum is correct. | |
475 | |
476 inflate() can decompress and check either zlib-wrapped or gzip-wrapped | |
477 deflate data. The header type is detected automatically, if requested when | |
478 initializing with inflateInit2(). Any information contained in the gzip | |
479 header is not retained, so applications that need that information should | |
480 instead use raw inflate, see inflateInit2() below, or inflateBack() and | |
481 perform their own processing of the gzip header and trailer. | |
482 | |
483 inflate() returns Z_OK if some progress has been made (more input processed | |
484 or more output produced), Z_STREAM_END if the end of the compressed data has | |
485 been reached and all uncompressed output has been produced, Z_NEED_DICT if a | |
486 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was | |
487 corrupted (input stream not conforming to the zlib format or incorrect check | |
488 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example | |
489 next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory, | |
490 Z_BUF_ERROR if no progress is possible or if there was not enough room in the | |
491 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and | |
492 inflate() can be called again with more input and more output space to | |
493 continue decompressing. If Z_DATA_ERROR is returned, the application may | |
494 then call inflateSync() to look for a good compression block if a partial | |
495 recovery of the data is desired. | |
496 */ | |
497 | |
498 | |
499 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); | |
500 /* | |
501 All dynamically allocated data structures for this stream are freed. | |
502 This function discards any unprocessed input and does not flush any pending | |
503 output. | |
504 | |
505 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state | |
506 was inconsistent. In the error case, msg may be set but then points to a | |
507 static string (which must not be deallocated). | |
508 */ | |
509 | |
510 | |
511 /* Advanced functions */ | |
512 | |
513 /* | |
514 The following functions are needed only in some special applications. | |
515 */ | |
516 | |
517 /* | |
518 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, | |
519 int level, | |
520 int method, | |
521 int windowBits, | |
522 int memLevel, | |
523 int strategy)); | |
524 | |
525 This is another version of deflateInit with more compression options. The | |
526 fields next_in, zalloc, zfree and opaque must be initialized before by the | |
527 caller. | |
528 | |
529 The method parameter is the compression method. It must be Z_DEFLATED in | |
530 this version of the library. | |
531 | |
532 The windowBits parameter is the base two logarithm of the window size | |
533 (the size of the history buffer). It should be in the range 8..15 for this | |
534 version of the library. Larger values of this parameter result in better | |
535 compression at the expense of memory usage. The default value is 15 if | |
536 deflateInit is used instead. | |
537 | |
538 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits | |
539 determines the window size. deflate() will then generate raw deflate data | |
540 with no zlib header or trailer, and will not compute an adler32 check value. | |
541 | |
542 windowBits can also be greater than 15 for optional gzip encoding. Add | |
543 16 to windowBits to write a simple gzip header and trailer around the | |
544 compressed data instead of a zlib wrapper. The gzip header will have no | |
545 file name, no extra data, no comment, no modification time (set to zero), no | |
546 header crc, and the operating system will be set to 255 (unknown). If a | |
547 gzip stream is being written, strm->adler is a crc32 instead of an adler32. | |
548 | |
549 The memLevel parameter specifies how much memory should be allocated | |
550 for the internal compression state. memLevel=1 uses minimum memory but is | |
551 slow and reduces compression ratio; memLevel=9 uses maximum memory for | |
552 optimal speed. The default value is 8. See zconf.h for total memory usage | |
553 as a function of windowBits and memLevel. | |
554 | |
555 The strategy parameter is used to tune the compression algorithm. Use the | |
556 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a | |
557 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no | |
558 string match), or Z_RLE to limit match distances to one (run-length | |
559 encoding). Filtered data consists mostly of small values with a somewhat | |
560 random distribution. In this case, the compression algorithm is tuned to | |
561 compress them better. The effect of Z_FILTERED is to force more Huffman | |
562 coding and less string matching; it is somewhat intermediate between | |
563 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as | |
564 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The | |
565 strategy parameter only affects the compression ratio but not the | |
566 correctness of the compressed output even if it is not set appropriately. | |
567 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler | |
568 decoder for special applications. | |
569 | |
570 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
571 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid | |
572 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is | |
573 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is | |
574 set to null if there is no error message. deflateInit2 does not perform any | |
575 compression: this will be done by deflate(). | |
576 */ | |
577 | |
578 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, | |
579 const Bytef *dictionary, | |
580 uInt dictLength)); | |
581 /* | |
582 Initializes the compression dictionary from the given byte sequence | |
583 without producing any compressed output. This function must be called | |
584 immediately after deflateInit, deflateInit2 or deflateReset, before any call | |
585 of deflate. The compressor and decompressor must use exactly the same | |
586 dictionary (see inflateSetDictionary). | |
587 | |
588 The dictionary should consist of strings (byte sequences) that are likely | |
589 to be encountered later in the data to be compressed, with the most commonly | |
590 used strings preferably put towards the end of the dictionary. Using a | |
591 dictionary is most useful when the data to be compressed is short and can be | |
592 predicted with good accuracy; the data can then be compressed better than | |
593 with the default empty dictionary. | |
594 | |
595 Depending on the size of the compression data structures selected by | |
596 deflateInit or deflateInit2, a part of the dictionary may in effect be | |
597 discarded, for example if the dictionary is larger than the window size | |
598 provided in deflateInit or deflateInit2. Thus the strings most likely to be | |
599 useful should be put at the end of the dictionary, not at the front. In | |
600 addition, the current implementation of deflate will use at most the window | |
601 size minus 262 bytes of the provided dictionary. | |
602 | |
603 Upon return of this function, strm->adler is set to the adler32 value | |
604 of the dictionary; the decompressor may later use this value to determine | |
605 which dictionary has been used by the compressor. (The adler32 value | |
606 applies to the whole dictionary even if only a subset of the dictionary is | |
607 actually used by the compressor.) If a raw deflate was requested, then the | |
608 adler32 value is not computed and strm->adler is not set. | |
609 | |
610 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a | |
611 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is | |
612 inconsistent (for example if deflate has already been called for this stream | |
613 or if the compression method is bsort). deflateSetDictionary does not | |
614 perform any compression: this will be done by deflate(). | |
615 */ | |
616 | |
617 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, | |
618 z_streamp source)); | |
619 /* | |
620 Sets the destination stream as a complete copy of the source stream. | |
621 | |
622 This function can be useful when several compression strategies will be | |
623 tried, for example when there are several ways of pre-processing the input | |
624 data with a filter. The streams that will be discarded should then be freed | |
625 by calling deflateEnd. Note that deflateCopy duplicates the internal | |
626 compression state which can be quite large, so this strategy is slow and can | |
627 consume lots of memory. | |
628 | |
629 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | |
630 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | |
631 (such as zalloc being Z_NULL). msg is left unchanged in both source and | |
632 destination. | |
633 */ | |
634 | |
635 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); | |
636 /* | |
637 This function is equivalent to deflateEnd followed by deflateInit, | |
638 but does not free and reallocate all the internal compression state. The | |
639 stream will keep the same compression level and any other attributes that | |
640 may have been set by deflateInit2. | |
641 | |
642 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | |
643 stream state was inconsistent (such as zalloc or state being Z_NULL). | |
644 */ | |
645 | |
646 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, | |
647 int level, | |
648 int strategy)); | |
649 /* | |
650 Dynamically update the compression level and compression strategy. The | |
651 interpretation of level and strategy is as in deflateInit2. This can be | |
652 used to switch between compression and straight copy of the input data, or | |
653 to switch to a different kind of input data requiring a different strategy. | |
654 If the compression level is changed, the input available so far is | |
655 compressed with the old level (and may be flushed); the new level will take | |
656 effect only at the next call of deflate(). | |
657 | |
658 Before the call of deflateParams, the stream state must be set as for | |
659 a call of deflate(), since the currently available input may have to be | |
660 compressed and flushed. In particular, strm->avail_out must be non-zero. | |
661 | |
662 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source | |
663 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if | |
664 strm->avail_out was zero. | |
665 */ | |
666 | |
667 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, | |
668 int good_length, | |
669 int max_lazy, | |
670 int nice_length, | |
671 int max_chain)); | |
672 /* | |
673 Fine tune deflate's internal compression parameters. This should only be | |
674 used by someone who understands the algorithm used by zlib's deflate for | |
675 searching for the best matching string, and even then only by the most | |
676 fanatic optimizer trying to squeeze out the last compressed bit for their | |
677 specific input data. Read the deflate.c source code for the meaning of the | |
678 max_lazy, good_length, nice_length, and max_chain parameters. | |
679 | |
680 deflateTune() can be called after deflateInit() or deflateInit2(), and | |
681 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. | |
682 */ | |
683 | |
684 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, | |
685 uLong sourceLen)); | |
686 /* | |
687 deflateBound() returns an upper bound on the compressed size after | |
688 deflation of sourceLen bytes. It must be called after deflateInit() or | |
689 deflateInit2(), and after deflateSetHeader(), if used. This would be used | |
690 to allocate an output buffer for deflation in a single pass, and so would be | |
691 called before deflate(). | |
692 */ | |
693 | |
694 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, | |
695 int bits, | |
696 int value)); | |
697 /* | |
698 deflatePrime() inserts bits in the deflate output stream. The intent | |
699 is that this function is used to start off the deflate output with the bits | |
700 leftover from a previous deflate stream when appending to it. As such, this | |
701 function can only be used for raw deflate, and must be used before the first | |
702 deflate() call after a deflateInit2() or deflateReset(). bits must be less | |
703 than or equal to 16, and that many of the least significant bits of value | |
704 will be inserted in the output. | |
705 | |
706 deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source | |
707 stream state was inconsistent. | |
708 */ | |
709 | |
710 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, | |
711 gz_headerp head)); | |
712 /* | |
713 deflateSetHeader() provides gzip header information for when a gzip | |
714 stream is requested by deflateInit2(). deflateSetHeader() may be called | |
715 after deflateInit2() or deflateReset() and before the first call of | |
716 deflate(). The text, time, os, extra field, name, and comment information | |
717 in the provided gz_header structure are written to the gzip header (xflag is | |
718 ignored -- the extra flags are set according to the compression level). The | |
719 caller must assure that, if not Z_NULL, name and comment are terminated with | |
720 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are | |
721 available there. If hcrc is true, a gzip header crc is included. Note that | |
722 the current versions of the command-line version of gzip (up through version | |
723 1.3.x) do not support header crc's, and will report that it is a "multi-part | |
724 gzip file" and give up. | |
725 | |
726 If deflateSetHeader is not used, the default gzip header has text false, | |
727 the time set to zero, and os set to 255, with no extra, name, or comment | |
728 fields. The gzip header is returned to the default state by deflateReset(). | |
729 | |
730 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source | |
731 stream state was inconsistent. | |
732 */ | |
733 | |
734 /* | |
735 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, | |
736 int windowBits)); | |
737 | |
738 This is another version of inflateInit with an extra parameter. The | |
739 fields next_in, avail_in, zalloc, zfree and opaque must be initialized | |
740 before by the caller. | |
741 | |
742 The windowBits parameter is the base two logarithm of the maximum window | |
743 size (the size of the history buffer). It should be in the range 8..15 for | |
744 this version of the library. The default value is 15 if inflateInit is used | |
745 instead. windowBits must be greater than or equal to the windowBits value | |
746 provided to deflateInit2() while compressing, or it must be equal to 15 if | |
747 deflateInit2() was not used. If a compressed stream with a larger window | |
748 size is given as input, inflate() will return with the error code | |
749 Z_DATA_ERROR instead of trying to allocate a larger window. | |
750 | |
751 windowBits can also be zero to request that inflate use the window size in | |
752 the zlib header of the compressed stream. | |
753 | |
754 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits | |
755 determines the window size. inflate() will then process raw deflate data, | |
756 not looking for a zlib or gzip header, not generating a check value, and not | |
757 looking for any check values for comparison at the end of the stream. This | |
758 is for use with other formats that use the deflate compressed data format | |
759 such as zip. Those formats provide their own check values. If a custom | |
760 format is developed using the raw deflate format for compressed data, it is | |
761 recommended that a check value such as an adler32 or a crc32 be applied to | |
762 the uncompressed data as is done in the zlib, gzip, and zip formats. For | |
763 most applications, the zlib format should be used as is. Note that comments | |
764 above on the use in deflateInit2() applies to the magnitude of windowBits. | |
765 | |
766 windowBits can also be greater than 15 for optional gzip decoding. Add | |
767 32 to windowBits to enable zlib and gzip decoding with automatic header | |
768 detection, or add 16 to decode only the gzip format (the zlib format will | |
769 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a | |
770 crc32 instead of an adler32. | |
771 | |
772 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
773 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the | |
774 version assumed by the caller, or Z_STREAM_ERROR if the parameters are | |
775 invalid, such as a null pointer to the structure. msg is set to null if | |
776 there is no error message. inflateInit2 does not perform any decompression | |
777 apart from possibly reading the zlib header if present: actual decompression | |
778 will be done by inflate(). (So next_in and avail_in may be modified, but | |
779 next_out and avail_out are unused and unchanged.) The current implementation | |
780 of inflateInit2() does not process any header information -- that is | |
781 deferred until inflate() is called. | |
782 */ | |
783 | |
784 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, | |
785 const Bytef *dictionary, | |
786 uInt dictLength)); | |
787 /* | |
788 Initializes the decompression dictionary from the given uncompressed byte | |
789 sequence. This function must be called immediately after a call of inflate, | |
790 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor | |
791 can be determined from the adler32 value returned by that call of inflate. | |
792 The compressor and decompressor must use exactly the same dictionary (see | |
793 deflateSetDictionary). For raw inflate, this function can be called | |
794 immediately after inflateInit2() or inflateReset() and before any call of | |
795 inflate() to set the dictionary. The application must insure that the | |
796 dictionary that was used for compression is provided. | |
797 | |
798 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a | |
799 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is | |
800 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the | |
801 expected one (incorrect adler32 value). inflateSetDictionary does not | |
802 perform any decompression: this will be done by subsequent calls of | |
803 inflate(). | |
804 */ | |
805 | |
806 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); | |
807 /* | |
808 Skips invalid compressed data until a full flush point (see above the | |
809 description of deflate with Z_FULL_FLUSH) can be found, or until all | |
810 available input is skipped. No output is provided. | |
811 | |
812 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR | |
813 if no more input was provided, Z_DATA_ERROR if no flush point has been | |
814 found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the | |
815 success case, the application may save the current current value of total_in | |
816 which indicates where valid compressed data was found. In the error case, | |
817 the application may repeatedly call inflateSync, providing more input each | |
818 time, until success or end of the input data. | |
819 */ | |
820 | |
821 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, | |
822 z_streamp source)); | |
823 /* | |
824 Sets the destination stream as a complete copy of the source stream. | |
825 | |
826 This function can be useful when randomly accessing a large stream. The | |
827 first pass through the stream can periodically record the inflate state, | |
828 allowing restarting inflate at those points when randomly accessing the | |
829 stream. | |
830 | |
831 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | |
832 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | |
833 (such as zalloc being Z_NULL). msg is left unchanged in both source and | |
834 destination. | |
835 */ | |
836 | |
837 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); | |
838 /* | |
839 This function is equivalent to inflateEnd followed by inflateInit, | |
840 but does not free and reallocate all the internal decompression state. The | |
841 stream will keep attributes that may have been set by inflateInit2. | |
842 | |
843 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | |
844 stream state was inconsistent (such as zalloc or state being Z_NULL). | |
845 */ | |
846 | |
847 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, | |
848 int windowBits)); | |
849 /* | |
850 This function is the same as inflateReset, but it also permits changing | |
851 the wrap and window size requests. The windowBits parameter is interpreted | |
852 the same as it is for inflateInit2. | |
853 | |
854 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source | |
855 stream state was inconsistent (such as zalloc or state being Z_NULL), or if | |
856 the windowBits parameter is invalid. | |
857 */ | |
858 | |
859 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, | |
860 int bits, | |
861 int value)); | |
862 /* | |
863 This function inserts bits in the inflate input stream. The intent is | |
864 that this function is used to start inflating at a bit position in the | |
865 middle of a byte. The provided bits will be used before any bytes are used | |
866 from next_in. This function should only be used with raw inflate, and | |
867 should be used before the first inflate() call after inflateInit2() or | |
868 inflateReset(). bits must be less than or equal to 16, and that many of the | |
869 least significant bits of value will be inserted in the input. | |
870 | |
871 If bits is negative, then the input stream bit buffer is emptied. Then | |
872 inflatePrime() can be called again to put bits in the buffer. This is used | |
873 to clear out bits leftover after feeding inflate a block description prior | |
874 to feeding inflate codes. | |
875 | |
876 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source | |
877 stream state was inconsistent. | |
878 */ | |
879 | |
880 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); | |
881 /* | |
882 This function returns two values, one in the lower 16 bits of the return | |
883 value, and the other in the remaining upper bits, obtained by shifting the | |
884 return value down 16 bits. If the upper value is -1 and the lower value is | |
885 zero, then inflate() is currently decoding information outside of a block. | |
886 If the upper value is -1 and the lower value is non-zero, then inflate is in | |
887 the middle of a stored block, with the lower value equaling the number of | |
888 bytes from the input remaining to copy. If the upper value is not -1, then | |
889 it is the number of bits back from the current bit position in the input of | |
890 the code (literal or length/distance pair) currently being processed. In | |
891 that case the lower value is the number of bytes already emitted for that | |
892 code. | |
893 | |
894 A code is being processed if inflate is waiting for more input to complete | |
895 decoding of the code, or if it has completed decoding but is waiting for | |
896 more output space to write the literal or match data. | |
897 | |
898 inflateMark() is used to mark locations in the input data for random | |
899 access, which may be at bit positions, and to note those cases where the | |
900 output of a code may span boundaries of random access blocks. The current | |
901 location in the input stream can be determined from avail_in and data_type | |
902 as noted in the description for the Z_BLOCK flush parameter for inflate. | |
903 | |
904 inflateMark returns the value noted above or -1 << 16 if the provided | |
905 source stream state was inconsistent. | |
906 */ | |
907 | |
908 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, | |
909 gz_headerp head)); | |
910 /* | |
911 inflateGetHeader() requests that gzip header information be stored in the | |
912 provided gz_header structure. inflateGetHeader() may be called after | |
913 inflateInit2() or inflateReset(), and before the first call of inflate(). | |
914 As inflate() processes the gzip stream, head->done is zero until the header | |
915 is completed, at which time head->done is set to one. If a zlib stream is | |
916 being decoded, then head->done is set to -1 to indicate that there will be | |
917 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be | |
918 used to force inflate() to return immediately after header processing is | |
919 complete and before any actual data is decompressed. | |
920 | |
921 The text, time, xflags, and os fields are filled in with the gzip header | |
922 contents. hcrc is set to true if there is a header CRC. (The header CRC | |
923 was valid if done is set to one.) If extra is not Z_NULL, then extra_max | |
924 contains the maximum number of bytes to write to extra. Once done is true, | |
925 extra_len contains the actual extra field length, and extra contains the | |
926 extra field, or that field truncated if extra_max is less than extra_len. | |
927 If name is not Z_NULL, then up to name_max characters are written there, | |
928 terminated with a zero unless the length is greater than name_max. If | |
929 comment is not Z_NULL, then up to comm_max characters are written there, | |
930 terminated with a zero unless the length is greater than comm_max. When any | |
931 of extra, name, or comment are not Z_NULL and the respective field is not | |
932 present in the header, then that field is set to Z_NULL to signal its | |
933 absence. This allows the use of deflateSetHeader() with the returned | |
934 structure to duplicate the header. However if those fields are set to | |
935 allocated memory, then the application will need to save those pointers | |
936 elsewhere so that they can be eventually freed. | |
937 | |
938 If inflateGetHeader is not used, then the header information is simply | |
939 discarded. The header is always checked for validity, including the header | |
940 CRC if present. inflateReset() will reset the process to discard the header | |
941 information. The application would need to call inflateGetHeader() again to | |
942 retrieve the header from the next gzip stream. | |
943 | |
944 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source | |
945 stream state was inconsistent. | |
946 */ | |
947 | |
948 /* | |
949 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, | |
950 unsigned char FAR *window)); | |
951 | |
952 Initialize the internal stream state for decompression using inflateBack() | |
953 calls. The fields zalloc, zfree and opaque in strm must be initialized | |
954 before the call. If zalloc and zfree are Z_NULL, then the default library- | |
955 derived memory allocation routines are used. windowBits is the base two | |
956 logarithm of the window size, in the range 8..15. window is a caller | |
957 supplied buffer of that size. Except for special applications where it is | |
958 assured that deflate was used with small window sizes, windowBits must be 15 | |
959 and a 32K byte window must be supplied to be able to decompress general | |
960 deflate streams. | |
961 | |
962 See inflateBack() for the usage of these routines. | |
963 | |
964 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of | |
965 the paramaters are invalid, Z_MEM_ERROR if the internal state could not be | |
966 allocated, or Z_VERSION_ERROR if the version of the library does not match | |
967 the version of the header file. | |
968 */ | |
969 | |
970 typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *)); | |
971 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); | |
972 | |
973 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, | |
974 in_func in, void FAR *in_desc, | |
975 out_func out, void FAR *out_desc)); | |
976 /* | |
977 inflateBack() does a raw inflate with a single call using a call-back | |
978 interface for input and output. This is more efficient than inflate() for | |
979 file i/o applications in that it avoids copying between the output and the | |
980 sliding window by simply making the window itself the output buffer. This | |
981 function trusts the application to not change the output buffer passed by | |
982 the output function, at least until inflateBack() returns. | |
983 | |
984 inflateBackInit() must be called first to allocate the internal state | |
985 and to initialize the state with the user-provided window buffer. | |
986 inflateBack() may then be used multiple times to inflate a complete, raw | |
987 deflate stream with each call. inflateBackEnd() is then called to free the | |
988 allocated state. | |
989 | |
990 A raw deflate stream is one with no zlib or gzip header or trailer. | |
991 This routine would normally be used in a utility that reads zip or gzip | |
992 files and writes out uncompressed files. The utility would decode the | |
993 header and process the trailer on its own, hence this routine expects only | |
994 the raw deflate stream to decompress. This is different from the normal | |
995 behavior of inflate(), which expects either a zlib or gzip header and | |
996 trailer around the deflate stream. | |
997 | |
998 inflateBack() uses two subroutines supplied by the caller that are then | |
999 called by inflateBack() for input and output. inflateBack() calls those | |
1000 routines until it reads a complete deflate stream and writes out all of the | |
1001 uncompressed data, or until it encounters an error. The function's | |
1002 parameters and return types are defined above in the in_func and out_func | |
1003 typedefs. inflateBack() will call in(in_desc, &buf) which should return the | |
1004 number of bytes of provided input, and a pointer to that input in buf. If | |
1005 there is no input available, in() must return zero--buf is ignored in that | |
1006 case--and inflateBack() will return a buffer error. inflateBack() will call | |
1007 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() | |
1008 should return zero on success, or non-zero on failure. If out() returns | |
1009 non-zero, inflateBack() will return with an error. Neither in() nor out() | |
1010 are permitted to change the contents of the window provided to | |
1011 inflateBackInit(), which is also the buffer that out() uses to write from. | |
1012 The length written by out() will be at most the window size. Any non-zero | |
1013 amount of input may be provided by in(). | |
1014 | |
1015 For convenience, inflateBack() can be provided input on the first call by | |
1016 setting strm->next_in and strm->avail_in. If that input is exhausted, then | |
1017 in() will be called. Therefore strm->next_in must be initialized before | |
1018 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called | |
1019 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in | |
1020 must also be initialized, and then if strm->avail_in is not zero, input will | |
1021 initially be taken from strm->next_in[0 .. strm->avail_in - 1]. | |
1022 | |
1023 The in_desc and out_desc parameters of inflateBack() is passed as the | |
1024 first parameter of in() and out() respectively when they are called. These | |
1025 descriptors can be optionally used to pass any information that the caller- | |
1026 supplied in() and out() functions need to do their job. | |
1027 | |
1028 On return, inflateBack() will set strm->next_in and strm->avail_in to | |
1029 pass back any unused input that was provided by the last in() call. The | |
1030 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR | |
1031 if in() or out() returned an error, Z_DATA_ERROR if there was a format error | |
1032 in the deflate stream (in which case strm->msg is set to indicate the nature | |
1033 of the error), or Z_STREAM_ERROR if the stream was not properly initialized. | |
1034 In the case of Z_BUF_ERROR, an input or output error can be distinguished | |
1035 using strm->next_in which will be Z_NULL only if in() returned an error. If | |
1036 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning | |
1037 non-zero. (in() will always be called before out(), so strm->next_in is | |
1038 assured to be defined if out() returns non-zero.) Note that inflateBack() | |
1039 cannot return Z_OK. | |
1040 */ | |
1041 | |
1042 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); | |
1043 /* | |
1044 All memory allocated by inflateBackInit() is freed. | |
1045 | |
1046 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream | |
1047 state was inconsistent. | |
1048 */ | |
1049 | |
1050 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); | |
1051 /* Return flags indicating compile-time options. | |
1052 | |
1053 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: | |
1054 1.0: size of uInt | |
1055 3.2: size of uLong | |
1056 5.4: size of voidpf (pointer) | |
1057 7.6: size of z_off_t | |
1058 | |
1059 Compiler, assembler, and debug options: | |
1060 8: DEBUG | |
1061 9: ASMV or ASMINF -- use ASM code | |
1062 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention | |
1063 11: 0 (reserved) | |
1064 | |
1065 One-time table building (smaller code, but not thread-safe if true): | |
1066 12: BUILDFIXED -- build static block decoding tables when needed | |
1067 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed | |
1068 14,15: 0 (reserved) | |
1069 | |
1070 Library content (indicates missing functionality): | |
1071 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking | |
1072 deflate code when not needed) | |
1073 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect | |
1074 and decode gzip streams (to avoid linking crc code) | |
1075 18-19: 0 (reserved) | |
1076 | |
1077 Operation variations (changes in library functionality): | |
1078 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate | |
1079 21: FASTEST -- deflate algorithm with only one, lowest compression level | |
1080 22,23: 0 (reserved) | |
1081 | |
1082 The sprintf variant used by gzprintf (zero is best): | |
1083 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format | |
1084 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! | |
1085 26: 0 = returns value, 1 = void -- 1 means inferred string length returned | |
1086 | |
1087 Remainder: | |
1088 27-31: 0 (reserved) | |
1089 */ | |
1090 | |
1091 | |
1092 /* utility functions */ | |
1093 | |
1094 /* | |
1095 The following utility functions are implemented on top of the basic | |
1096 stream-oriented functions. To simplify the interface, some default options | |
1097 are assumed (compression level and memory usage, standard memory allocation | |
1098 functions). The source code of these utility functions can be modified if | |
1099 you need special options. | |
1100 */ | |
1101 | |
1102 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, | |
1103 const Bytef *source, uLong sourceLen)); | |
1104 /* | |
1105 Compresses the source buffer into the destination buffer. sourceLen is | |
1106 the byte length of the source buffer. Upon entry, destLen is the total size | |
1107 of the destination buffer, which must be at least the value returned by | |
1108 compressBound(sourceLen). Upon exit, destLen is the actual size of the | |
1109 compressed buffer. | |
1110 | |
1111 compress returns Z_OK if success, Z_MEM_ERROR if there was not | |
1112 enough memory, Z_BUF_ERROR if there was not enough room in the output | |
1113 buffer. | |
1114 */ | |
1115 | |
1116 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, | |
1117 const Bytef *source, uLong sourceLen, | |
1118 int level)); | |
1119 /* | |
1120 Compresses the source buffer into the destination buffer. The level | |
1121 parameter has the same meaning as in deflateInit. sourceLen is the byte | |
1122 length of the source buffer. Upon entry, destLen is the total size of the | |
1123 destination buffer, which must be at least the value returned by | |
1124 compressBound(sourceLen). Upon exit, destLen is the actual size of the | |
1125 compressed buffer. | |
1126 | |
1127 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
1128 memory, Z_BUF_ERROR if there was not enough room in the output buffer, | |
1129 Z_STREAM_ERROR if the level parameter is invalid. | |
1130 */ | |
1131 | |
1132 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); | |
1133 /* | |
1134 compressBound() returns an upper bound on the compressed size after | |
1135 compress() or compress2() on sourceLen bytes. It would be used before a | |
1136 compress() or compress2() call to allocate the destination buffer. | |
1137 */ | |
1138 | |
1139 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, | |
1140 const Bytef *source, uLong sourceLen)); | |
1141 /* | |
1142 Decompresses the source buffer into the destination buffer. sourceLen is | |
1143 the byte length of the source buffer. Upon entry, destLen is the total size | |
1144 of the destination buffer, which must be large enough to hold the entire | |
1145 uncompressed data. (The size of the uncompressed data must have been saved | |
1146 previously by the compressor and transmitted to the decompressor by some | |
1147 mechanism outside the scope of this compression library.) Upon exit, destLen | |
1148 is the actual size of the uncompressed buffer. | |
1149 | |
1150 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not | |
1151 enough memory, Z_BUF_ERROR if there was not enough room in the output | |
1152 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. | |
1153 */ | |
1154 | |
1155 | |
1156 /* gzip file access functions */ | |
1157 | |
1158 /* | |
1159 This library supports reading and writing files in gzip (.gz) format with | |
1160 an interface similar to that of stdio, using the functions that start with | |
1161 "gz". The gzip format is different from the zlib format. gzip is a gzip | |
1162 wrapper, documented in RFC 1952, wrapped around a deflate stream. | |
1163 */ | |
1164 | |
1165 typedef voidp gzFile; /* opaque gzip file descriptor */ | |
1166 | |
1167 /* | |
1168 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); | |
1169 | |
1170 Opens a gzip (.gz) file for reading or writing. The mode parameter is as | |
1171 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or | |
1172 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only | |
1173 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' | |
1174 for fixed code compression as in "wb9F". (See the description of | |
1175 deflateInit2 for more information about the strategy parameter.) Also "a" | |
1176 can be used instead of "w" to request that the gzip stream that will be | |
1177 written be appended to the file. "+" will result in an error, since reading | |
1178 and writing to the same gzip file is not supported. | |
1179 | |
1180 gzopen can be used to read a file which is not in gzip format; in this | |
1181 case gzread will directly read from the file without decompression. | |
1182 | |
1183 gzopen returns NULL if the file could not be opened, if there was | |
1184 insufficient memory to allocate the gzFile state, or if an invalid mode was | |
1185 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). | |
1186 errno can be checked to determine if the reason gzopen failed was that the | |
1187 file could not be opened. | |
1188 */ | |
1189 | |
1190 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); | |
1191 /* | |
1192 gzdopen associates a gzFile with the file descriptor fd. File descriptors | |
1193 are obtained from calls like open, dup, creat, pipe or fileno (if the file | |
1194 has been previously opened with fopen). The mode parameter is as in gzopen. | |
1195 | |
1196 The next call of gzclose on the returned gzFile will also close the file | |
1197 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor | |
1198 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, | |
1199 mode);. The duplicated descriptor should be saved to avoid a leak, since | |
1200 gzdopen does not close fd if it fails. | |
1201 | |
1202 gzdopen returns NULL if there was insufficient memory to allocate the | |
1203 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not | |
1204 provided, or '+' was provided), or if fd is -1. The file descriptor is not | |
1205 used until the next gz* read, write, seek, or close operation, so gzdopen | |
1206 will not detect if fd is invalid (unless fd is -1). | |
1207 */ | |
1208 | |
1209 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); | |
1210 /* | |
1211 Set the internal buffer size used by this library's functions. The | |
1212 default buffer size is 8192 bytes. This function must be called after | |
1213 gzopen() or gzdopen(), and before any other calls that read or write the | |
1214 file. The buffer memory allocation is always deferred to the first read or | |
1215 write. Two buffers are allocated, either both of the specified size when | |
1216 writing, or one of the specified size and the other twice that size when | |
1217 reading. A larger buffer size of, for example, 64K or 128K bytes will | |
1218 noticeably increase the speed of decompression (reading). | |
1219 | |
1220 The new buffer size also affects the maximum length for gzprintf(). | |
1221 | |
1222 gzbuffer() returns 0 on success, or -1 on failure, such as being called | |
1223 too late. | |
1224 */ | |
1225 | |
1226 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); | |
1227 /* | |
1228 Dynamically update the compression level or strategy. See the description | |
1229 of deflateInit2 for the meaning of these parameters. | |
1230 | |
1231 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not | |
1232 opened for writing. | |
1233 */ | |
1234 | |
1235 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); | |
1236 /* | |
1237 Reads the given number of uncompressed bytes from the compressed file. If | |
1238 the input file was not in gzip format, gzread copies the given number of | |
1239 bytes into the buffer. | |
1240 | |
1241 After reaching the end of a gzip stream in the input, gzread will continue | |
1242 to read, looking for another gzip stream, or failing that, reading the rest | |
1243 of the input file directly without decompression. The entire input file | |
1244 will be read if gzread is called until it returns less than the requested | |
1245 len. | |
1246 | |
1247 gzread returns the number of uncompressed bytes actually read, less than | |
1248 len for end of file, or -1 for error. | |
1249 */ | |
1250 | |
1251 ZEXTERN int ZEXPORT gzwrite OF((gzFile file, | |
1252 voidpc buf, unsigned len)); | |
1253 /* | |
1254 Writes the given number of uncompressed bytes into the compressed file. | |
1255 gzwrite returns the number of uncompressed bytes written or 0 in case of | |
1256 error. | |
1257 */ | |
1258 | |
1259 ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); | |
1260 /* | |
1261 Converts, formats, and writes the arguments to the compressed file under | |
1262 control of the format string, as in fprintf. gzprintf returns the number of | |
1263 uncompressed bytes actually written, or 0 in case of error. The number of | |
1264 uncompressed bytes written is limited to 8191, or one less than the buffer | |
1265 size given to gzbuffer(). The caller should assure that this limit is not | |
1266 exceeded. If it is exceeded, then gzprintf() will return an error (0) with | |
1267 nothing written. In this case, there may also be a buffer overflow with | |
1268 unpredictable consequences, which is possible only if zlib was compiled with | |
1269 the insecure functions sprintf() or vsprintf() because the secure snprintf() | |
1270 or vsnprintf() functions were not available. This can be determined using | |
1271 zlibCompileFlags(). | |
1272 */ | |
1273 | |
1274 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); | |
1275 /* | |
1276 Writes the given null-terminated string to the compressed file, excluding | |
1277 the terminating null character. | |
1278 | |
1279 gzputs returns the number of characters written, or -1 in case of error. | |
1280 */ | |
1281 | |
1282 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); | |
1283 /* | |
1284 Reads bytes from the compressed file until len-1 characters are read, or a | |
1285 newline character is read and transferred to buf, or an end-of-file | |
1286 condition is encountered. If any characters are read or if len == 1, the | |
1287 string is terminated with a null character. If no characters are read due | |
1288 to an end-of-file or len < 1, then the buffer is left untouched. | |
1289 | |
1290 gzgets returns buf which is a null-terminated string, or it returns NULL | |
1291 for end-of-file or in case of error. If there was an error, the contents at | |
1292 buf are indeterminate. | |
1293 */ | |
1294 | |
1295 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); | |
1296 /* | |
1297 Writes c, converted to an unsigned char, into the compressed file. gzputc | |
1298 returns the value that was written, or -1 in case of error. | |
1299 */ | |
1300 | |
1301 ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); | |
1302 /* | |
1303 Reads one byte from the compressed file. gzgetc returns this byte or -1 | |
1304 in case of end of file or error. | |
1305 */ | |
1306 | |
1307 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); | |
1308 /* | |
1309 Push one character back onto the stream to be read as the first character | |
1310 on the next read. At least one character of push-back is allowed. | |
1311 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will | |
1312 fail if c is -1, and may fail if a character has been pushed but not read | |
1313 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the | |
1314 output buffer size of pushed characters is allowed. (See gzbuffer above.) | |
1315 The pushed character will be discarded if the stream is repositioned with | |
1316 gzseek() or gzrewind(). | |
1317 */ | |
1318 | |
1319 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); | |
1320 /* | |
1321 Flushes all pending output into the compressed file. The parameter flush | |
1322 is as in the deflate() function. The return value is the zlib error number | |
1323 (see function gzerror below). gzflush is only permitted when writing. | |
1324 | |
1325 If the flush parameter is Z_FINISH, the remaining data is written and the | |
1326 gzip stream is completed in the output. If gzwrite() is called again, a new | |
1327 gzip stream will be started in the output. gzread() is able to read such | |
1328 concatented gzip streams. | |
1329 | |
1330 gzflush should be called only when strictly necessary because it will | |
1331 degrade compression if called too often. | |
1332 */ | |
1333 | |
1334 /* | |
1335 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, | |
1336 z_off_t offset, int whence)); | |
1337 | |
1338 Sets the starting position for the next gzread or gzwrite on the given | |
1339 compressed file. The offset represents a number of bytes in the | |
1340 uncompressed data stream. The whence parameter is defined as in lseek(2); | |
1341 the value SEEK_END is not supported. | |
1342 | |
1343 If the file is opened for reading, this function is emulated but can be | |
1344 extremely slow. If the file is opened for writing, only forward seeks are | |
1345 supported; gzseek then compresses a sequence of zeroes up to the new | |
1346 starting position. | |
1347 | |
1348 gzseek returns the resulting offset location as measured in bytes from | |
1349 the beginning of the uncompressed stream, or -1 in case of error, in | |
1350 particular if the file is opened for writing and the new starting position | |
1351 would be before the current position. | |
1352 */ | |
1353 | |
1354 ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); | |
1355 /* | |
1356 Rewinds the given file. This function is supported only for reading. | |
1357 | |
1358 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) | |
1359 */ | |
1360 | |
1361 /* | |
1362 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); | |
1363 | |
1364 Returns the starting position for the next gzread or gzwrite on the given | |
1365 compressed file. This position represents a number of bytes in the | |
1366 uncompressed data stream, and is zero when starting, even if appending or | |
1367 reading a gzip stream from the middle of a file using gzdopen(). | |
1368 | |
1369 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) | |
1370 */ | |
1371 | |
1372 /* | |
1373 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); | |
1374 | |
1375 Returns the current offset in the file being read or written. This offset | |
1376 includes the count of bytes that precede the gzip stream, for example when | |
1377 appending or when using gzdopen() for reading. When reading, the offset | |
1378 does not include as yet unused buffered input. This information can be used | |
1379 for a progress indicator. On error, gzoffset() returns -1. | |
1380 */ | |
1381 | |
1382 ZEXTERN int ZEXPORT gzeof OF((gzFile file)); | |
1383 /* | |
1384 Returns true (1) if the end-of-file indicator has been set while reading, | |
1385 false (0) otherwise. Note that the end-of-file indicator is set only if the | |
1386 read tried to go past the end of the input, but came up short. Therefore, | |
1387 just like feof(), gzeof() may return false even if there is no more data to | |
1388 read, in the event that the last read request was for the exact number of | |
1389 bytes remaining in the input file. This will happen if the input file size | |
1390 is an exact multiple of the buffer size. | |
1391 | |
1392 If gzeof() returns true, then the read functions will return no more data, | |
1393 unless the end-of-file indicator is reset by gzclearerr() and the input file | |
1394 has grown since the previous end of file was detected. | |
1395 */ | |
1396 | |
1397 ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); | |
1398 /* | |
1399 Returns true (1) if file is being copied directly while reading, or false | |
1400 (0) if file is a gzip stream being decompressed. This state can change from | |
1401 false to true while reading the input file if the end of a gzip stream is | |
1402 reached, but is followed by data that is not another gzip stream. | |
1403 | |
1404 If the input file is empty, gzdirect() will return true, since the input | |
1405 does not contain a gzip stream. | |
1406 | |
1407 If gzdirect() is used immediately after gzopen() or gzdopen() it will | |
1408 cause buffers to be allocated to allow reading the file to determine if it | |
1409 is a gzip file. Therefore if gzbuffer() is used, it should be called before | |
1410 gzdirect(). | |
1411 */ | |
1412 | |
1413 ZEXTERN int ZEXPORT gzclose OF((gzFile file)); | |
1414 /* | |
1415 Flushes all pending output if necessary, closes the compressed file and | |
1416 deallocates the (de)compression state. Note that once file is closed, you | |
1417 cannot call gzerror with file, since its structures have been deallocated. | |
1418 gzclose must not be called more than once on the same file, just as free | |
1419 must not be called more than once on the same allocation. | |
1420 | |
1421 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a | |
1422 file operation error, or Z_OK on success. | |
1423 */ | |
1424 | |
1425 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); | |
1426 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); | |
1427 /* | |
1428 Same as gzclose(), but gzclose_r() is only for use when reading, and | |
1429 gzclose_w() is only for use when writing or appending. The advantage to | |
1430 using these instead of gzclose() is that they avoid linking in zlib | |
1431 compression or decompression code that is not used when only reading or only | |
1432 writing respectively. If gzclose() is used, then both compression and | |
1433 decompression code will be included the application when linking to a static | |
1434 zlib library. | |
1435 */ | |
1436 | |
1437 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); | |
1438 /* | |
1439 Returns the error message for the last error which occurred on the given | |
1440 compressed file. errnum is set to zlib error number. If an error occurred | |
1441 in the file system and not in the compression library, errnum is set to | |
1442 Z_ERRNO and the application may consult errno to get the exact error code. | |
1443 | |
1444 The application must not modify the returned string. Future calls to | |
1445 this function may invalidate the previously returned string. If file is | |
1446 closed, then the string previously returned by gzerror will no longer be | |
1447 available. | |
1448 | |
1449 gzerror() should be used to distinguish errors from end-of-file for those | |
1450 functions above that do not distinguish those cases in their return values. | |
1451 */ | |
1452 | |
1453 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); | |
1454 /* | |
1455 Clears the error and end-of-file flags for file. This is analogous to the | |
1456 clearerr() function in stdio. This is useful for continuing to read a gzip | |
1457 file that is being written concurrently. | |
1458 */ | |
1459 | |
1460 | |
1461 /* checksum functions */ | |
1462 | |
1463 /* | |
1464 These functions are not related to compression but are exported | |
1465 anyway because they might be useful in applications using the compression | |
1466 library. | |
1467 */ | |
1468 | |
1469 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); | |
1470 /* | |
1471 Update a running Adler-32 checksum with the bytes buf[0..len-1] and | |
1472 return the updated checksum. If buf is Z_NULL, this function returns the | |
1473 required initial value for the checksum. | |
1474 | |
1475 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed | |
1476 much faster. | |
1477 | |
1478 Usage example: | |
1479 | |
1480 uLong adler = adler32(0L, Z_NULL, 0); | |
1481 | |
1482 while (read_buffer(buffer, length) != EOF) { | |
1483 adler = adler32(adler, buffer, length); | |
1484 } | |
1485 if (adler != original_adler) error(); | |
1486 */ | |
1487 | |
1488 /* | |
1489 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, | |
1490 z_off_t len2)); | |
1491 | |
1492 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 | |
1493 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for | |
1494 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of | |
1495 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. | |
1496 */ | |
1497 | |
1498 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); | |
1499 /* | |
1500 Update a running CRC-32 with the bytes buf[0..len-1] and return the | |
1501 updated CRC-32. If buf is Z_NULL, this function returns the required | |
1502 initial value for the for the crc. Pre- and post-conditioning (one's | |
1503 complement) is performed within this function so it shouldn't be done by the | |
1504 application. | |
1505 | |
1506 Usage example: | |
1507 | |
1508 uLong crc = crc32(0L, Z_NULL, 0); | |
1509 | |
1510 while (read_buffer(buffer, length) != EOF) { | |
1511 crc = crc32(crc, buffer, length); | |
1512 } | |
1513 if (crc != original_crc) error(); | |
1514 */ | |
1515 | |
1516 /* | |
1517 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); | |
1518 | |
1519 Combine two CRC-32 check values into one. For two sequences of bytes, | |
1520 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were | |
1521 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 | |
1522 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and | |
1523 len2. | |
1524 */ | |
1525 | |
1526 | |
1527 /* various hacks, don't look :) */ | |
1528 | |
1529 /* deflateInit and inflateInit are macros to allow checking the zlib version | |
1530 * and the compiler's view of z_stream: | |
1531 */ | |
1532 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, | |
1533 const char *version, int stream_size)); | |
1534 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, | |
1535 const char *version, int stream_size)); | |
1536 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, | |
1537 int windowBits, int memLevel, | |
1538 int strategy, const char *version, | |
1539 int stream_size)); | |
1540 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, | |
1541 const char *version, int stream_size)); | |
1542 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, | |
1543 unsigned char FAR *window, | |
1544 const char *version, | |
1545 int stream_size)); | |
1546 #define deflateInit(strm, level) \ | |
1547 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) | |
1548 #define inflateInit(strm) \ | |
1549 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) | |
1550 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ | |
1551 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ | |
1552 (strategy), ZLIB_VERSION, sizeof(z_stream)) | |
1553 #define inflateInit2(strm, windowBits) \ | |
1554 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) | |
1555 #define inflateBackInit(strm, windowBits, window) \ | |
1556 inflateBackInit_((strm), (windowBits), (window), \ | |
1557 ZLIB_VERSION, sizeof(z_stream)) | |
1558 | |
1559 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or | |
1560 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if | |
1561 * both are true, the application gets the *64 functions, and the regular | |
1562 * functions are changed to 64 bits) -- in case these are set on systems | |
1563 * without large file support, _LFS64_LARGEFILE must also be true | |
1564 */ | |
1565 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0 | |
1566 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); | |
1567 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); | |
1568 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); | |
1569 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); | |
1570 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); | |
1571 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); | |
1572 #endif | |
1573 | |
1574 #if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0 | |
1575 # define gzopen gzopen64 | |
1576 # define gzseek gzseek64 | |
1577 # define gztell gztell64 | |
1578 # define gzoffset gzoffset64 | |
1579 # define adler32_combine adler32_combine64 | |
1580 # define crc32_combine crc32_combine64 | |
1581 # ifdef _LARGEFILE64_SOURCE | |
1582 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); | |
1583 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); | |
1584 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); | |
1585 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); | |
1586 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); | |
1587 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); | |
1588 # endif | |
1589 #else | |
1590 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); | |
1591 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); | |
1592 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); | |
1593 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); | |
1594 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); | |
1595 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); | |
1596 #endif | |
1597 | |
1598 /* hack for buggy compilers */ | |
1599 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) | |
1600 struct internal_state {int dummy;}; | |
1601 #endif | |
1602 | |
1603 /* undocumented functions */ | |
1604 ZEXTERN const char * ZEXPORT zError OF((int)); | |
1605 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); | |
1606 ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void)); | |
1607 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); | |
1608 | |
1609 #ifdef __cplusplus | |
1610 } | |
1611 #endif | |
1612 | |
1613 #endif /* ZLIB_H */ |