cc68a136 |
1 | /* zlib.h -- interface of the 'zlib' general purpose compression library\r |
2 | version 1.2.1, November 17th, 2003\r |
3 | \r |
4 | Copyright (C) 1995-2003 Jean-loup Gailly and Mark Adler\r |
5 | \r |
6 | This software is provided 'as-is', without any express or implied\r |
7 | warranty. In no event will the authors be held liable for any damages\r |
8 | arising from the use of this software.\r |
9 | \r |
10 | Permission is granted to anyone to use this software for any purpose,\r |
11 | including commercial applications, and to alter it and redistribute it\r |
12 | freely, subject to the following restrictions:\r |
13 | \r |
14 | 1. The origin of this software must not be misrepresented; you must not\r |
15 | claim that you wrote the original software. If you use this software\r |
16 | in a product, an acknowledgment in the product documentation would be\r |
17 | appreciated but is not required.\r |
18 | 2. Altered source versions must be plainly marked as such, and must not be\r |
19 | misrepresented as being the original software.\r |
20 | 3. This notice may not be removed or altered from any source distribution.\r |
21 | \r |
22 | Jean-loup Gailly Mark Adler\r |
23 | jloup@gzip.org madler@alumni.caltech.edu\r |
24 | \r |
25 | \r |
26 | The data format used by the zlib library is described by RFCs (Request for\r |
27 | Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt\r |
28 | (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).\r |
29 | */\r |
30 | \r |
31 | #ifndef ZLIB_H\r |
32 | #define ZLIB_H\r |
33 | \r |
34 | #include "zconf.h"\r |
35 | \r |
36 | #ifdef __cplusplus\r |
37 | extern "C" {\r |
38 | #endif\r |
39 | \r |
40 | #define ZLIB_VERSION "1.2.1"\r |
41 | #define ZLIB_VERNUM 0x1210\r |
42 | \r |
43 | /*\r |
44 | The 'zlib' compression library provides in-memory compression and\r |
45 | decompression functions, including integrity checks of the uncompressed\r |
46 | data. This version of the library supports only one compression method\r |
47 | (deflation) but other algorithms will be added later and will have the same\r |
48 | stream interface.\r |
49 | \r |
50 | Compression can be done in a single step if the buffers are large\r |
51 | enough (for example if an input file is mmap'ed), or can be done by\r |
52 | repeated calls of the compression function. In the latter case, the\r |
53 | application must provide more input and/or consume the output\r |
54 | (providing more output space) before each call.\r |
55 | \r |
56 | The compressed data format used by the in-memory functions is the zlib\r |
57 | format, which is a zlib wrapper documented in RFC 1950, wrapped around a\r |
58 | deflate stream, which is itself documented in RFC 1951.\r |
59 | \r |
60 | The library also supports reading and writing files in gzip (.gz) format\r |
61 | with an interface similar to that of stdio using the functions that start\r |
62 | with "gz". The gzip format is different from the zlib format. gzip is a\r |
63 | gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.\r |
64 | \r |
65 | The zlib format was designed to be compact and fast for use in memory\r |
66 | and on communications channels. The gzip format was designed for single-\r |
67 | file compression on file systems, has a larger header than zlib to maintain\r |
68 | directory information, and uses a different, slower check method than zlib.\r |
69 | \r |
70 | This library does not provide any functions to write gzip files in memory.\r |
71 | However such functions could be easily written using zlib's deflate function,\r |
72 | the documentation in the gzip RFC, and the examples in gzio.c.\r |
73 | \r |
74 | The library does not install any signal handler. The decoder checks\r |
75 | the consistency of the compressed data, so the library should never\r |
76 | crash even in case of corrupted input.\r |
77 | */\r |
78 | \r |
79 | typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));\r |
80 | typedef void (*free_func) OF((voidpf opaque, voidpf address));\r |
81 | \r |
82 | struct internal_state;\r |
83 | \r |
84 | typedef struct z_stream_s {\r |
85 | Bytef *next_in; /* next input byte */\r |
86 | uInt avail_in; /* number of bytes available at next_in */\r |
87 | uLong total_in; /* total nb of input bytes read so far */\r |
88 | \r |
89 | Bytef *next_out; /* next output byte should be put there */\r |
90 | uInt avail_out; /* remaining free space at next_out */\r |
91 | uLong total_out; /* total nb of bytes output so far */\r |
92 | \r |
93 | char *msg; /* last error message, NULL if no error */\r |
94 | struct internal_state FAR *state; /* not visible by applications */\r |
95 | \r |
96 | alloc_func zalloc; /* used to allocate the internal state */\r |
97 | free_func zfree; /* used to free the internal state */\r |
98 | voidpf opaque; /* private data object passed to zalloc and zfree */\r |
99 | \r |
100 | int data_type; /* best guess about the data type: ascii or binary */\r |
101 | uLong adler; /* adler32 value of the uncompressed data */\r |
102 | uLong reserved; /* reserved for future use */\r |
103 | } z_stream;\r |
104 | \r |
105 | typedef z_stream FAR *z_streamp;\r |
106 | \r |
107 | /*\r |
108 | The application must update next_in and avail_in when avail_in has\r |
109 | dropped to zero. It must update next_out and avail_out when avail_out\r |
110 | has dropped to zero. The application must initialize zalloc, zfree and\r |
111 | opaque before calling the init function. All other fields are set by the\r |
112 | compression library and must not be updated by the application.\r |
113 | \r |
114 | The opaque value provided by the application will be passed as the first\r |
115 | parameter for calls of zalloc and zfree. This can be useful for custom\r |
116 | memory management. The compression library attaches no meaning to the\r |
117 | opaque value.\r |
118 | \r |
119 | zalloc must return Z_NULL if there is not enough memory for the object.\r |
120 | If zlib is used in a multi-threaded application, zalloc and zfree must be\r |
121 | thread safe.\r |
122 | \r |
123 | On 16-bit systems, the functions zalloc and zfree must be able to allocate\r |
124 | exactly 65536 bytes, but will not be required to allocate more than this\r |
125 | if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,\r |
126 | pointers returned by zalloc for objects of exactly 65536 bytes *must*\r |
127 | have their offset normalized to zero. The default allocation function\r |
128 | provided by this library ensures this (see zutil.c). To reduce memory\r |
129 | requirements and avoid any allocation of 64K objects, at the expense of\r |
130 | compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).\r |
131 | \r |
132 | The fields total_in and total_out can be used for statistics or\r |
133 | progress reports. After compression, total_in holds the total size of\r |
134 | the uncompressed data and may be saved for use in the decompressor\r |
135 | (particularly if the decompressor wants to decompress everything in\r |
136 | a single step).\r |
137 | */\r |
138 | \r |
139 | /* constants */\r |
140 | \r |
141 | #define Z_NO_FLUSH 0\r |
142 | #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */\r |
143 | #define Z_SYNC_FLUSH 2\r |
144 | #define Z_FULL_FLUSH 3\r |
145 | #define Z_FINISH 4\r |
146 | #define Z_BLOCK 5\r |
147 | /* Allowed flush values; see deflate() and inflate() below for details */\r |
148 | \r |
149 | #define Z_OK 0\r |
150 | #define Z_STREAM_END 1\r |
151 | #define Z_NEED_DICT 2\r |
152 | #define Z_ERRNO (-1)\r |
153 | #define Z_STREAM_ERROR (-2)\r |
154 | #define Z_DATA_ERROR (-3)\r |
155 | #define Z_MEM_ERROR (-4)\r |
156 | #define Z_BUF_ERROR (-5)\r |
157 | #define Z_VERSION_ERROR (-6)\r |
158 | /* Return codes for the compression/decompression functions. Negative\r |
159 | * values are errors, positive values are used for special but normal events.\r |
160 | */\r |
161 | \r |
162 | #define Z_NO_COMPRESSION 0\r |
163 | #define Z_BEST_SPEED 1\r |
164 | #define Z_BEST_COMPRESSION 9\r |
165 | #define Z_DEFAULT_COMPRESSION (-1)\r |
166 | /* compression levels */\r |
167 | \r |
168 | #define Z_FILTERED 1\r |
169 | #define Z_HUFFMAN_ONLY 2\r |
170 | #define Z_RLE 3\r |
171 | #define Z_DEFAULT_STRATEGY 0\r |
172 | /* compression strategy; see deflateInit2() below for details */\r |
173 | \r |
174 | #define Z_BINARY 0\r |
175 | #define Z_ASCII 1\r |
176 | #define Z_UNKNOWN 2\r |
177 | /* Possible values of the data_type field (though see inflate()) */\r |
178 | \r |
179 | #define Z_DEFLATED 8\r |
180 | /* The deflate compression method (the only one supported in this version) */\r |
181 | \r |
182 | #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */\r |
183 | \r |
184 | #define zlib_version zlibVersion()\r |
185 | /* for compatibility with versions < 1.0.2 */\r |
186 | \r |
187 | /* basic functions */\r |
188 | \r |
189 | ZEXTERN const char * ZEXPORT zlibVersion OF((void));\r |
190 | /* The application can compare zlibVersion and ZLIB_VERSION for consistency.\r |
191 | If the first character differs, the library code actually used is\r |
192 | not compatible with the zlib.h header file used by the application.\r |
193 | This check is automatically made by deflateInit and inflateInit.\r |
194 | */\r |
195 | \r |
196 | /*\r |
197 | ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));\r |
198 | \r |
199 | Initializes the internal stream state for compression. The fields\r |
200 | zalloc, zfree and opaque must be initialized before by the caller.\r |
201 | If zalloc and zfree are set to Z_NULL, deflateInit updates them to\r |
202 | use default allocation functions.\r |
203 | \r |
204 | The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:\r |
205 | 1 gives best speed, 9 gives best compression, 0 gives no compression at\r |
206 | all (the input data is simply copied a block at a time).\r |
207 | Z_DEFAULT_COMPRESSION requests a default compromise between speed and\r |
208 | compression (currently equivalent to level 6).\r |
209 | \r |
210 | deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not\r |
211 | enough memory, Z_STREAM_ERROR if level is not a valid compression level,\r |
212 | Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible\r |
213 | with the version assumed by the caller (ZLIB_VERSION).\r |
214 | msg is set to null if there is no error message. deflateInit does not\r |
215 | perform any compression: this will be done by deflate().\r |
216 | */\r |
217 | \r |
218 | \r |
219 | ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));\r |
220 | /*\r |
221 | deflate compresses as much data as possible, and stops when the input\r |
222 | buffer becomes empty or the output buffer becomes full. It may introduce some\r |
223 | output latency (reading input without producing any output) except when\r |
224 | forced to flush.\r |
225 | \r |
226 | The detailed semantics are as follows. deflate performs one or both of the\r |
227 | following actions:\r |
228 | \r |
229 | - Compress more input starting at next_in and update next_in and avail_in\r |
230 | accordingly. If not all input can be processed (because there is not\r |
231 | enough room in the output buffer), next_in and avail_in are updated and\r |
232 | processing will resume at this point for the next call of deflate().\r |
233 | \r |
234 | - Provide more output starting at next_out and update next_out and avail_out\r |
235 | accordingly. This action is forced if the parameter flush is non zero.\r |
236 | Forcing flush frequently degrades the compression ratio, so this parameter\r |
237 | should be set only when necessary (in interactive applications).\r |
238 | Some output may be provided even if flush is not set.\r |
239 | \r |
240 | Before the call of deflate(), the application should ensure that at least\r |
241 | one of the actions is possible, by providing more input and/or consuming\r |
242 | more output, and updating avail_in or avail_out accordingly; avail_out\r |
243 | should never be zero before the call. The application can consume the\r |
244 | compressed output when it wants, for example when the output buffer is full\r |
245 | (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK\r |
246 | and with zero avail_out, it must be called again after making room in the\r |
247 | output buffer because there might be more output pending.\r |
248 | \r |
249 | If the parameter flush is set to Z_SYNC_FLUSH, all pending output is\r |
250 | flushed to the output buffer and the output is aligned on a byte boundary, so\r |
251 | that the decompressor can get all input data available so far. (In particular\r |
252 | avail_in is zero after the call if enough output space has been provided\r |
253 | before the call.) Flushing may degrade compression for some compression\r |
254 | algorithms and so it should be used only when necessary.\r |
255 | \r |
256 | If flush is set to Z_FULL_FLUSH, all output is flushed as with\r |
257 | Z_SYNC_FLUSH, and the compression state is reset so that decompression can\r |
258 | restart from this point if previous compressed data has been damaged or if\r |
259 | random access is desired. Using Z_FULL_FLUSH too often can seriously degrade\r |
260 | the compression.\r |
261 | \r |
262 | If deflate returns with avail_out == 0, this function must be called again\r |
263 | with the same value of the flush parameter and more output space (updated\r |
264 | avail_out), until the flush is complete (deflate returns with non-zero\r |
265 | avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that\r |
266 | avail_out is greater than six to avoid repeated flush markers due to\r |
267 | avail_out == 0 on return.\r |
268 | \r |
269 | If the parameter flush is set to Z_FINISH, pending input is processed,\r |
270 | pending output is flushed and deflate returns with Z_STREAM_END if there\r |
271 | was enough output space; if deflate returns with Z_OK, this function must be\r |
272 | called again with Z_FINISH and more output space (updated avail_out) but no\r |
273 | more input data, until it returns with Z_STREAM_END or an error. After\r |
274 | deflate has returned Z_STREAM_END, the only possible operations on the\r |
275 | stream are deflateReset or deflateEnd.\r |
276 | \r |
277 | Z_FINISH can be used immediately after deflateInit if all the compression\r |
278 | is to be done in a single step. In this case, avail_out must be at least\r |
279 | the value returned by deflateBound (see below). If deflate does not return\r |
280 | Z_STREAM_END, then it must be called again as described above.\r |
281 | \r |
282 | deflate() sets strm->adler to the adler32 checksum of all input read\r |
283 | so far (that is, total_in bytes).\r |
284 | \r |
285 | deflate() may update data_type if it can make a good guess about\r |
286 | the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered\r |
287 | binary. This field is only for information purposes and does not affect\r |
288 | the compression algorithm in any manner.\r |
289 | \r |
290 | deflate() returns Z_OK if some progress has been made (more input\r |
291 | processed or more output produced), Z_STREAM_END if all input has been\r |
292 | consumed and all output has been produced (only when flush is set to\r |
293 | Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example\r |
294 | if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible\r |
295 | (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not\r |
296 | fatal, and deflate() can be called again with more input and more output\r |
297 | space to continue compressing.\r |
298 | */\r |
299 | \r |
300 | \r |
301 | ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));\r |
302 | /*\r |
303 | All dynamically allocated data structures for this stream are freed.\r |
304 | This function discards any unprocessed input and does not flush any\r |
305 | pending output.\r |
306 | \r |
307 | deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the\r |
308 | stream state was inconsistent, Z_DATA_ERROR if the stream was freed\r |
309 | prematurely (some input or output was discarded). In the error case,\r |
310 | msg may be set but then points to a static string (which must not be\r |
311 | deallocated).\r |
312 | */\r |
313 | \r |
314 | \r |
315 | /*\r |
316 | ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));\r |
317 | \r |
318 | Initializes the internal stream state for decompression. The fields\r |
319 | next_in, avail_in, zalloc, zfree and opaque must be initialized before by\r |
320 | the caller. If next_in is not Z_NULL and avail_in is large enough (the exact\r |
321 | value depends on the compression method), inflateInit determines the\r |
322 | compression method from the zlib header and allocates all data structures\r |
323 | accordingly; otherwise the allocation will be deferred to the first call of\r |
324 | inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to\r |
325 | use default allocation functions.\r |
326 | \r |
327 | inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough\r |
328 | memory, Z_VERSION_ERROR if the zlib library version is incompatible with the\r |
329 | version assumed by the caller. msg is set to null if there is no error\r |
330 | message. inflateInit does not perform any decompression apart from reading\r |
331 | the zlib header if present: this will be done by inflate(). (So next_in and\r |
332 | avail_in may be modified, but next_out and avail_out are unchanged.)\r |
333 | */\r |
334 | \r |
335 | \r |
336 | ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));\r |
337 | /*\r |
338 | inflate decompresses as much data as possible, and stops when the input\r |
339 | buffer becomes empty or the output buffer becomes full. It may introduce\r |
340 | some output latency (reading input without producing any output) except when\r |
341 | forced to flush.\r |
342 | \r |
343 | The detailed semantics are as follows. inflate performs one or both of the\r |
344 | following actions:\r |
345 | \r |
346 | - Decompress more input starting at next_in and update next_in and avail_in\r |
347 | accordingly. If not all input can be processed (because there is not\r |
348 | enough room in the output buffer), next_in is updated and processing\r |
349 | will resume at this point for the next call of inflate().\r |
350 | \r |
351 | - Provide more output starting at next_out and update next_out and avail_out\r |
352 | accordingly. inflate() provides as much output as possible, until there\r |
353 | is no more input data or no more space in the output buffer (see below\r |
354 | about the flush parameter).\r |
355 | \r |
356 | Before the call of inflate(), the application should ensure that at least\r |
357 | one of the actions is possible, by providing more input and/or consuming\r |
358 | more output, and updating the next_* and avail_* values accordingly.\r |
359 | The application can consume the uncompressed output when it wants, for\r |
360 | example when the output buffer is full (avail_out == 0), or after each\r |
361 | call of inflate(). If inflate returns Z_OK and with zero avail_out, it\r |
362 | must be called again after making room in the output buffer because there\r |
363 | might be more output pending.\r |
364 | \r |
365 | The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,\r |
366 | Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much\r |
367 | output as possible to the output buffer. Z_BLOCK requests that inflate() stop\r |
368 | if and when it get to the next deflate block boundary. When decoding the zlib\r |
369 | or gzip format, this will cause inflate() to return immediately after the\r |
370 | header and before the first block. When doing a raw inflate, inflate() will\r |
371 | go ahead and process the first block, and will return when it gets to the end\r |
372 | of that block, or when it runs out of data.\r |
373 | \r |
374 | The Z_BLOCK option assists in appending to or combining deflate streams.\r |
375 | Also to assist in this, on return inflate() will set strm->data_type to the\r |
376 | number of unused bits in the last byte taken from strm->next_in, plus 64\r |
377 | if inflate() is currently decoding the last block in the deflate stream,\r |
378 | plus 128 if inflate() returned immediately after decoding an end-of-block\r |
379 | code or decoding the complete header up to just before the first byte of the\r |
380 | deflate stream. The end-of-block will not be indicated until all of the\r |
381 | uncompressed data from that block has been written to strm->next_out. The\r |
382 | number of unused bits may in general be greater than seven, except when\r |
383 | bit 7 of data_type is set, in which case the number of unused bits will be\r |
384 | less than eight.\r |
385 | \r |
386 | inflate() should normally be called until it returns Z_STREAM_END or an\r |
387 | error. However if all decompression is to be performed in a single step\r |
388 | (a single call of inflate), the parameter flush should be set to\r |
389 | Z_FINISH. In this case all pending input is processed and all pending\r |
390 | output is flushed; avail_out must be large enough to hold all the\r |
391 | uncompressed data. (The size of the uncompressed data may have been saved\r |
392 | by the compressor for this purpose.) The next operation on this stream must\r |
393 | be inflateEnd to deallocate the decompression state. The use of Z_FINISH\r |
394 | is never required, but can be used to inform inflate that a faster approach\r |
395 | may be used for the single inflate() call.\r |
396 | \r |
397 | In this implementation, inflate() always flushes as much output as\r |
398 | possible to the output buffer, and always uses the faster approach on the\r |
399 | first call. So the only effect of the flush parameter in this implementation\r |
400 | is on the return value of inflate(), as noted below, or when it returns early\r |
401 | because Z_BLOCK is used.\r |
402 | \r |
403 | If a preset dictionary is needed after this call (see inflateSetDictionary\r |
404 | below), inflate sets strm-adler to the adler32 checksum of the dictionary\r |
405 | chosen by the compressor and returns Z_NEED_DICT; otherwise it sets\r |
406 | strm->adler to the adler32 checksum of all output produced so far (that is,\r |
407 | total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described\r |
408 | below. At the end of the stream, inflate() checks that its computed adler32\r |
409 | checksum is equal to that saved by the compressor and returns Z_STREAM_END\r |
410 | only if the checksum is correct.\r |
411 | \r |
412 | inflate() will decompress and check either zlib-wrapped or gzip-wrapped\r |
413 | deflate data. The header type is detected automatically. Any information\r |
414 | contained in the gzip header is not retained, so applications that need that\r |
415 | information should instead use raw inflate, see inflateInit2() below, or\r |
416 | inflateBack() and perform their own processing of the gzip header and\r |
417 | trailer.\r |
418 | \r |
419 | inflate() returns Z_OK if some progress has been made (more input processed\r |
420 | or more output produced), Z_STREAM_END if the end of the compressed data has\r |
421 | been reached and all uncompressed output has been produced, Z_NEED_DICT if a\r |
422 | preset dictionary is needed at this point, Z_DATA_ERROR if the input data was\r |
423 | corrupted (input stream not conforming to the zlib format or incorrect check\r |
424 | value), Z_STREAM_ERROR if the stream structure was inconsistent (for example\r |
425 | if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,\r |
426 | Z_BUF_ERROR if no progress is possible or if there was not enough room in the\r |
427 | output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and\r |
428 | inflate() can be called again with more input and more output space to\r |
429 | continue decompressing. If Z_DATA_ERROR is returned, the application may then\r |
430 | call inflateSync() to look for a good compression block if a partial recovery\r |
431 | of the data is desired.\r |
432 | */\r |
433 | \r |
434 | \r |
435 | ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));\r |
436 | /*\r |
437 | All dynamically allocated data structures for this stream are freed.\r |
438 | This function discards any unprocessed input and does not flush any\r |
439 | pending output.\r |
440 | \r |
441 | inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state\r |
442 | was inconsistent. In the error case, msg may be set but then points to a\r |
443 | static string (which must not be deallocated).\r |
444 | */\r |
445 | \r |
446 | /* Advanced functions */\r |
447 | \r |
448 | /*\r |
449 | The following functions are needed only in some special applications.\r |
450 | */\r |
451 | \r |
452 | /*\r |
453 | ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,\r |
454 | int level,\r |
455 | int method,\r |
456 | int windowBits,\r |
457 | int memLevel,\r |
458 | int strategy));\r |
459 | \r |
460 | This is another version of deflateInit with more compression options. The\r |
461 | fields next_in, zalloc, zfree and opaque must be initialized before by\r |
462 | the caller.\r |
463 | \r |
464 | The method parameter is the compression method. It must be Z_DEFLATED in\r |
465 | this version of the library.\r |
466 | \r |
467 | The windowBits parameter is the base two logarithm of the window size\r |
468 | (the size of the history buffer). It should be in the range 8..15 for this\r |
469 | version of the library. Larger values of this parameter result in better\r |
470 | compression at the expense of memory usage. The default value is 15 if\r |
471 | deflateInit is used instead.\r |
472 | \r |
473 | windowBits can also be -8..-15 for raw deflate. In this case, -windowBits\r |
474 | determines the window size. deflate() will then generate raw deflate data\r |
475 | with no zlib header or trailer, and will not compute an adler32 check value.\r |
476 | \r |
477 | windowBits can also be greater than 15 for optional gzip encoding. Add\r |
478 | 16 to windowBits to write a simple gzip header and trailer around the\r |
479 | compressed data instead of a zlib wrapper. The gzip header will have no\r |
480 | file name, no extra data, no comment, no modification time (set to zero),\r |
481 | no header crc, and the operating system will be set to 255 (unknown).\r |
482 | \r |
483 | The memLevel parameter specifies how much memory should be allocated\r |
484 | for the internal compression state. memLevel=1 uses minimum memory but\r |
485 | is slow and reduces compression ratio; memLevel=9 uses maximum memory\r |
486 | for optimal speed. The default value is 8. See zconf.h for total memory\r |
487 | usage as a function of windowBits and memLevel.\r |
488 | \r |
489 | The strategy parameter is used to tune the compression algorithm. Use the\r |
490 | value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a\r |
491 | filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no\r |
492 | string match), or Z_RLE to limit match distances to one (run-length\r |
493 | encoding). Filtered data consists mostly of small values with a somewhat\r |
494 | random distribution. In this case, the compression algorithm is tuned to\r |
495 | compress them better. The effect of Z_FILTERED is to force more Huffman\r |
496 | coding and less string matching; it is somewhat intermediate between\r |
497 | Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as\r |
498 | Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy\r |
499 | parameter only affects the compression ratio but not the correctness of the\r |
500 | compressed output even if it is not set appropriately.\r |
501 | \r |
502 | deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough\r |
503 | memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid\r |
504 | method). msg is set to null if there is no error message. deflateInit2 does\r |
505 | not perform any compression: this will be done by deflate().\r |
506 | */\r |
507 | \r |
508 | ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,\r |
509 | const Bytef *dictionary,\r |
510 | uInt dictLength));\r |
511 | /*\r |
512 | Initializes the compression dictionary from the given byte sequence\r |
513 | without producing any compressed output. This function must be called\r |
514 | immediately after deflateInit, deflateInit2 or deflateReset, before any\r |
515 | call of deflate. The compressor and decompressor must use exactly the same\r |
516 | dictionary (see inflateSetDictionary).\r |
517 | \r |
518 | The dictionary should consist of strings (byte sequences) that are likely\r |
519 | to be encountered later in the data to be compressed, with the most commonly\r |
520 | used strings preferably put towards the end of the dictionary. Using a\r |
521 | dictionary is most useful when the data to be compressed is short and can be\r |
522 | predicted with good accuracy; the data can then be compressed better than\r |
523 | with the default empty dictionary.\r |
524 | \r |
525 | Depending on the size of the compression data structures selected by\r |
526 | deflateInit or deflateInit2, a part of the dictionary may in effect be\r |
527 | discarded, for example if the dictionary is larger than the window size in\r |
528 | deflate or deflate2. Thus the strings most likely to be useful should be\r |
529 | put at the end of the dictionary, not at the front.\r |
530 | \r |
531 | Upon return of this function, strm->adler is set to the adler32 value\r |
532 | of the dictionary; the decompressor may later use this value to determine\r |
533 | which dictionary has been used by the compressor. (The adler32 value\r |
534 | applies to the whole dictionary even if only a subset of the dictionary is\r |
535 | actually used by the compressor.) If a raw deflate was requested, then the\r |
536 | adler32 value is not computed and strm->adler is not set.\r |
537 | \r |
538 | deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a\r |
539 | parameter is invalid (such as NULL dictionary) or the stream state is\r |
540 | inconsistent (for example if deflate has already been called for this stream\r |
541 | or if the compression method is bsort). deflateSetDictionary does not\r |
542 | perform any compression: this will be done by deflate().\r |
543 | */\r |
544 | \r |
545 | ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,\r |
546 | z_streamp source));\r |
547 | /*\r |
548 | Sets the destination stream as a complete copy of the source stream.\r |
549 | \r |
550 | This function can be useful when several compression strategies will be\r |
551 | tried, for example when there are several ways of pre-processing the input\r |
552 | data with a filter. The streams that will be discarded should then be freed\r |
553 | by calling deflateEnd. Note that deflateCopy duplicates the internal\r |
554 | compression state which can be quite large, so this strategy is slow and\r |
555 | can consume lots of memory.\r |
556 | \r |
557 | deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not\r |
558 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent\r |
559 | (such as zalloc being NULL). msg is left unchanged in both source and\r |
560 | destination.\r |
561 | */\r |
562 | \r |
563 | ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));\r |
564 | /*\r |
565 | This function is equivalent to deflateEnd followed by deflateInit,\r |
566 | but does not free and reallocate all the internal compression state.\r |
567 | The stream will keep the same compression level and any other attributes\r |
568 | that may have been set by deflateInit2.\r |
569 | \r |
570 | deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source\r |
571 | stream state was inconsistent (such as zalloc or state being NULL).\r |
572 | */\r |
573 | \r |
574 | ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,\r |
575 | int level,\r |
576 | int strategy));\r |
577 | /*\r |
578 | Dynamically update the compression level and compression strategy. The\r |
579 | interpretation of level and strategy is as in deflateInit2. This can be\r |
580 | used to switch between compression and straight copy of the input data, or\r |
581 | to switch to a different kind of input data requiring a different\r |
582 | strategy. If the compression level is changed, the input available so far\r |
583 | is compressed with the old level (and may be flushed); the new level will\r |
584 | take effect only at the next call of deflate().\r |
585 | \r |
586 | Before the call of deflateParams, the stream state must be set as for\r |
587 | a call of deflate(), since the currently available input may have to\r |
588 | be compressed and flushed. In particular, strm->avail_out must be non-zero.\r |
589 | \r |
590 | deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source\r |
591 | stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR\r |
592 | if strm->avail_out was zero.\r |
593 | */\r |
594 | \r |
595 | ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,\r |
596 | uLong sourceLen));\r |
597 | /*\r |
598 | deflateBound() returns an upper bound on the compressed size after\r |
599 | deflation of sourceLen bytes. It must be called after deflateInit()\r |
600 | or deflateInit2(). This would be used to allocate an output buffer\r |
601 | for deflation in a single pass, and so would be called before deflate().\r |
602 | */\r |
603 | \r |
604 | ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,\r |
605 | int bits,\r |
606 | int value));\r |
607 | /*\r |
608 | deflatePrime() inserts bits in the deflate output stream. The intent\r |
609 | is that this function is used to start off the deflate output with the\r |
610 | bits leftover from a previous deflate stream when appending to it. As such,\r |
611 | this function can only be used for raw deflate, and must be used before the\r |
612 | first deflate() call after a deflateInit2() or deflateReset(). bits must be\r |
613 | less than or equal to 16, and that many of the least significant bits of\r |
614 | value will be inserted in the output.\r |
615 | \r |
616 | deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source\r |
617 | stream state was inconsistent.\r |
618 | */\r |
619 | \r |
620 | /*\r |
621 | ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,\r |
622 | int windowBits));\r |
623 | \r |
624 | This is another version of inflateInit with an extra parameter. The\r |
625 | fields next_in, avail_in, zalloc, zfree and opaque must be initialized\r |
626 | before by the caller.\r |
627 | \r |
628 | The windowBits parameter is the base two logarithm of the maximum window\r |
629 | size (the size of the history buffer). It should be in the range 8..15 for\r |
630 | this version of the library. The default value is 15 if inflateInit is used\r |
631 | instead. windowBits must be greater than or equal to the windowBits value\r |
632 | provided to deflateInit2() while compressing, or it must be equal to 15 if\r |
633 | deflateInit2() was not used. If a compressed stream with a larger window\r |
634 | size is given as input, inflate() will return with the error code\r |
635 | Z_DATA_ERROR instead of trying to allocate a larger window.\r |
636 | \r |
637 | windowBits can also be -8..-15 for raw inflate. In this case, -windowBits\r |
638 | determines the window size. inflate() will then process raw deflate data,\r |
639 | not looking for a zlib or gzip header, not generating a check value, and not\r |
640 | looking for any check values for comparison at the end of the stream. This\r |
641 | is for use with other formats that use the deflate compressed data format\r |
642 | such as zip. Those formats provide their own check values. If a custom\r |
643 | format is developed using the raw deflate format for compressed data, it is\r |
644 | recommended that a check value such as an adler32 or a crc32 be applied to\r |
645 | the uncompressed data as is done in the zlib, gzip, and zip formats. For\r |
646 | most applications, the zlib format should be used as is. Note that comments\r |
647 | above on the use in deflateInit2() applies to the magnitude of windowBits.\r |
648 | \r |
649 | windowBits can also be greater than 15 for optional gzip decoding. Add\r |
650 | 32 to windowBits to enable zlib and gzip decoding with automatic header\r |
651 | detection, or add 16 to decode only the gzip format (the zlib format will\r |
652 | return a Z_DATA_ERROR).\r |
653 | \r |
654 | inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough\r |
655 | memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative\r |
656 | memLevel). msg is set to null if there is no error message. inflateInit2\r |
657 | does not perform any decompression apart from reading the zlib header if\r |
658 | present: this will be done by inflate(). (So next_in and avail_in may be\r |
659 | modified, but next_out and avail_out are unchanged.)\r |
660 | */\r |
661 | \r |
662 | ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,\r |
663 | const Bytef *dictionary,\r |
664 | uInt dictLength));\r |
665 | /*\r |
666 | Initializes the decompression dictionary from the given uncompressed byte\r |
667 | sequence. This function must be called immediately after a call of inflate\r |
668 | if this call returned Z_NEED_DICT. The dictionary chosen by the compressor\r |
669 | can be determined from the adler32 value returned by this call of\r |
670 | inflate. The compressor and decompressor must use exactly the same\r |
671 | dictionary (see deflateSetDictionary).\r |
672 | \r |
673 | inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a\r |
674 | parameter is invalid (such as NULL dictionary) or the stream state is\r |
675 | inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the\r |
676 | expected one (incorrect adler32 value). inflateSetDictionary does not\r |
677 | perform any decompression: this will be done by subsequent calls of\r |
678 | inflate().\r |
679 | */\r |
680 | \r |
681 | ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));\r |
682 | /*\r |
683 | Skips invalid compressed data until a full flush point (see above the\r |
684 | description of deflate with Z_FULL_FLUSH) can be found, or until all\r |
685 | available input is skipped. No output is provided.\r |
686 | \r |
687 | inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR\r |
688 | if no more input was provided, Z_DATA_ERROR if no flush point has been found,\r |
689 | or Z_STREAM_ERROR if the stream structure was inconsistent. In the success\r |
690 | case, the application may save the current current value of total_in which\r |
691 | indicates where valid compressed data was found. In the error case, the\r |
692 | application may repeatedly call inflateSync, providing more input each time,\r |
693 | until success or end of the input data.\r |
694 | */\r |
695 | \r |
696 | ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,\r |
697 | z_streamp source));\r |
698 | /*\r |
699 | Sets the destination stream as a complete copy of the source stream.\r |
700 | \r |
701 | This function can be useful when randomly accessing a large stream. The\r |
702 | first pass through the stream can periodically record the inflate state,\r |
703 | allowing restarting inflate at those points when randomly accessing the\r |
704 | stream.\r |
705 | \r |
706 | inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not\r |
707 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent\r |
708 | (such as zalloc being NULL). msg is left unchanged in both source and\r |
709 | destination.\r |
710 | */\r |
711 | \r |
712 | ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));\r |
713 | /*\r |
714 | This function is equivalent to inflateEnd followed by inflateInit,\r |
715 | but does not free and reallocate all the internal decompression state.\r |
716 | The stream will keep attributes that may have been set by inflateInit2.\r |
717 | \r |
718 | inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source\r |
719 | stream state was inconsistent (such as zalloc or state being NULL).\r |
720 | */\r |
721 | \r |
722 | /*\r |
723 | ZEXTERN int ZEXPORT inflateBackInit OF((z_stream FAR *strm, int windowBits,\r |
724 | unsigned char FAR *window));\r |
725 | \r |
726 | Initialize the internal stream state for decompression using inflateBack()\r |
727 | calls. The fields zalloc, zfree and opaque in strm must be initialized\r |
728 | before the call. If zalloc and zfree are Z_NULL, then the default library-\r |
729 | derived memory allocation routines are used. windowBits is the base two\r |
730 | logarithm of the window size, in the range 8..15. window is a caller\r |
731 | supplied buffer of that size. Except for special applications where it is\r |
732 | assured that deflate was used with small window sizes, windowBits must be 15\r |
733 | and a 32K byte window must be supplied to be able to decompress general\r |
734 | deflate streams.\r |
735 | \r |
736 | See inflateBack() for the usage of these routines.\r |
737 | \r |
738 | inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of\r |
739 | the paramaters are invalid, Z_MEM_ERROR if the internal state could not\r |
740 | be allocated, or Z_VERSION_ERROR if the version of the library does not\r |
741 | match the version of the header file.\r |
742 | */\r |
743 | \r |
744 | typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));\r |
745 | typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));\r |
746 | \r |
747 | ZEXTERN int ZEXPORT inflateBack OF((z_stream FAR *strm,\r |
748 | in_func in, void FAR *in_desc,\r |
749 | out_func out, void FAR *out_desc));\r |
750 | /*\r |
751 | inflateBack() does a raw inflate with a single call using a call-back\r |
752 | interface for input and output. This is more efficient than inflate() for\r |
753 | file i/o applications in that it avoids copying between the output and the\r |
754 | sliding window by simply making the window itself the output buffer. This\r |
755 | function trusts the application to not change the output buffer passed by\r |
756 | the output function, at least until inflateBack() returns.\r |
757 | \r |
758 | inflateBackInit() must be called first to allocate the internal state\r |
759 | and to initialize the state with the user-provided window buffer.\r |
760 | inflateBack() may then be used multiple times to inflate a complete, raw\r |
761 | deflate stream with each call. inflateBackEnd() is then called to free\r |
762 | the allocated state.\r |
763 | \r |
764 | A raw deflate stream is one with no zlib or gzip header or trailer.\r |
765 | This routine would normally be used in a utility that reads zip or gzip\r |
766 | files and writes out uncompressed files. The utility would decode the\r |
767 | header and process the trailer on its own, hence this routine expects\r |
768 | only the raw deflate stream to decompress. This is different from the\r |
769 | normal behavior of inflate(), which expects either a zlib or gzip header and\r |
770 | trailer around the deflate stream.\r |
771 | \r |
772 | inflateBack() uses two subroutines supplied by the caller that are then\r |
773 | called by inflateBack() for input and output. inflateBack() calls those\r |
774 | routines until it reads a complete deflate stream and writes out all of the\r |
775 | uncompressed data, or until it encounters an error. The function's\r |
776 | parameters and return types are defined above in the in_func and out_func\r |
777 | typedefs. inflateBack() will call in(in_desc, &buf) which should return the\r |
778 | number of bytes of provided input, and a pointer to that input in buf. If\r |
779 | there is no input available, in() must return zero--buf is ignored in that\r |
780 | case--and inflateBack() will return a buffer error. inflateBack() will call\r |
781 | out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()\r |
782 | should return zero on success, or non-zero on failure. If out() returns\r |
783 | non-zero, inflateBack() will return with an error. Neither in() nor out()\r |
784 | are permitted to change the contents of the window provided to\r |
785 | inflateBackInit(), which is also the buffer that out() uses to write from.\r |
786 | The length written by out() will be at most the window size. Any non-zero\r |
787 | amount of input may be provided by in().\r |
788 | \r |
789 | For convenience, inflateBack() can be provided input on the first call by\r |
790 | setting strm->next_in and strm->avail_in. If that input is exhausted, then\r |
791 | in() will be called. Therefore strm->next_in must be initialized before\r |
792 | calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called\r |
793 | immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in\r |
794 | must also be initialized, and then if strm->avail_in is not zero, input will\r |
795 | initially be taken from strm->next_in[0 .. strm->avail_in - 1].\r |
796 | \r |
797 | The in_desc and out_desc parameters of inflateBack() is passed as the\r |
798 | first parameter of in() and out() respectively when they are called. These\r |
799 | descriptors can be optionally used to pass any information that the caller-\r |
800 | supplied in() and out() functions need to do their job.\r |
801 | \r |
802 | On return, inflateBack() will set strm->next_in and strm->avail_in to\r |
803 | pass back any unused input that was provided by the last in() call. The\r |
804 | return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR\r |
805 | if in() or out() returned an error, Z_DATA_ERROR if there was a format\r |
806 | error in the deflate stream (in which case strm->msg is set to indicate the\r |
807 | nature of the error), or Z_STREAM_ERROR if the stream was not properly\r |
808 | initialized. In the case of Z_BUF_ERROR, an input or output error can be\r |
809 | distinguished using strm->next_in which will be Z_NULL only if in() returned\r |
810 | an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to\r |
811 | out() returning non-zero. (in() will always be called before out(), so\r |
812 | strm->next_in is assured to be defined if out() returns non-zero.) Note\r |
813 | that inflateBack() cannot return Z_OK.\r |
814 | */\r |
815 | \r |
816 | ZEXTERN int ZEXPORT inflateBackEnd OF((z_stream FAR *strm));\r |
817 | /*\r |
818 | All memory allocated by inflateBackInit() is freed.\r |
819 | \r |
820 | inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream\r |
821 | state was inconsistent.\r |
822 | */\r |
823 | \r |
824 | ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));\r |
825 | /* Return flags indicating compile-time options.\r |
826 | \r |
827 | Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:\r |
828 | 1.0: size of uInt\r |
829 | 3.2: size of uLong\r |
830 | 5.4: size of voidpf (pointer)\r |
831 | 7.6: size of z_off_t\r |
832 | \r |
833 | Compiler, assembler, and debug options:\r |
834 | 8: DEBUG\r |
835 | 9: ASMV or ASMINF -- use ASM code\r |
836 | 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention\r |
837 | 11: 0 (reserved)\r |
838 | \r |
839 | One-time table building (smaller code, but not thread-safe if true):\r |
840 | 12: BUILDFIXED -- build static block decoding tables when needed\r |
841 | 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed\r |
842 | 14,15: 0 (reserved)\r |
843 | \r |
844 | Library content (indicates missing functionality):\r |
845 | 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking\r |
846 | deflate code when not needed)\r |
847 | 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect\r |
848 | and decode gzip streams (to avoid linking crc code)\r |
849 | 18-19: 0 (reserved)\r |
850 | \r |
851 | Operation variations (changes in library functionality):\r |
852 | 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate\r |
853 | 21: QUICKEST -- deflate algorithm with only one, lowest compression level\r |
854 | 22,23: 0 (reserved)\r |
855 | \r |
856 | The sprintf variant used by gzprintf (zero is best):\r |
857 | 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format\r |
858 | 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!\r |
859 | 26: 0 = returns value, 1 = void -- 1 means inferred string length returned\r |
860 | \r |
861 | Remainder:\r |
862 | 27-31: 0 (reserved)\r |
863 | */\r |
864 | \r |
865 | \r |
866 | /* utility functions */\r |
867 | \r |
868 | /*\r |
869 | The following utility functions are implemented on top of the\r |
870 | basic stream-oriented functions. To simplify the interface, some\r |
871 | default options are assumed (compression level and memory usage,\r |
872 | standard memory allocation functions). The source code of these\r |
873 | utility functions can easily be modified if you need special options.\r |
874 | */\r |
875 | \r |
876 | ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,\r |
877 | const Bytef *source, uLong sourceLen));\r |
878 | /*\r |
879 | Compresses the source buffer into the destination buffer. sourceLen is\r |
880 | the byte length of the source buffer. Upon entry, destLen is the total\r |
881 | size of the destination buffer, which must be at least the value returned\r |
882 | by compressBound(sourceLen). Upon exit, destLen is the actual size of the\r |
883 | compressed buffer.\r |
884 | This function can be used to compress a whole file at once if the\r |
885 | input file is mmap'ed.\r |
886 | compress returns Z_OK if success, Z_MEM_ERROR if there was not\r |
887 | enough memory, Z_BUF_ERROR if there was not enough room in the output\r |
888 | buffer.\r |
889 | */\r |
890 | \r |
891 | ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,\r |
892 | const Bytef *source, uLong sourceLen,\r |
893 | int level));\r |
894 | /*\r |
895 | Compresses the source buffer into the destination buffer. The level\r |
896 | parameter has the same meaning as in deflateInit. sourceLen is the byte\r |
897 | length of the source buffer. Upon entry, destLen is the total size of the\r |
898 | destination buffer, which must be at least the value returned by\r |
899 | compressBound(sourceLen). Upon exit, destLen is the actual size of the\r |
900 | compressed buffer.\r |
901 | \r |
902 | compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough\r |
903 | memory, Z_BUF_ERROR if there was not enough room in the output buffer,\r |
904 | Z_STREAM_ERROR if the level parameter is invalid.\r |
905 | */\r |
906 | \r |
907 | ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));\r |
908 | /*\r |
909 | compressBound() returns an upper bound on the compressed size after\r |
910 | compress() or compress2() on sourceLen bytes. It would be used before\r |
911 | a compress() or compress2() call to allocate the destination buffer.\r |
912 | */\r |
913 | \r |
914 | ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,\r |
915 | const Bytef *source, uLong sourceLen));\r |
916 | /*\r |
917 | Decompresses the source buffer into the destination buffer. sourceLen is\r |
918 | the byte length of the source buffer. Upon entry, destLen is the total\r |
919 | size of the destination buffer, which must be large enough to hold the\r |
920 | entire uncompressed data. (The size of the uncompressed data must have\r |
921 | been saved previously by the compressor and transmitted to the decompressor\r |
922 | by some mechanism outside the scope of this compression library.)\r |
923 | Upon exit, destLen is the actual size of the compressed buffer.\r |
924 | This function can be used to decompress a whole file at once if the\r |
925 | input file is mmap'ed.\r |
926 | \r |
927 | uncompress returns Z_OK if success, Z_MEM_ERROR if there was not\r |
928 | enough memory, Z_BUF_ERROR if there was not enough room in the output\r |
929 | buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.\r |
930 | */\r |
931 | \r |
932 | \r |
933 | typedef voidp gzFile;\r |
934 | \r |
935 | ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));\r |
936 | /*\r |
937 | Opens a gzip (.gz) file for reading or writing. The mode parameter\r |
938 | is as in fopen ("rb" or "wb") but can also include a compression level\r |
939 | ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for\r |
940 | Huffman only compression as in "wb1h", or 'R' for run-length encoding\r |
941 | as in "wb1R". (See the description of deflateInit2 for more information\r |
942 | about the strategy parameter.)\r |
943 | \r |
944 | gzopen can be used to read a file which is not in gzip format; in this\r |
945 | case gzread will directly read from the file without decompression.\r |
946 | \r |
947 | gzopen returns NULL if the file could not be opened or if there was\r |
948 | insufficient memory to allocate the (de)compression state; errno\r |
949 | can be checked to distinguish the two cases (if errno is zero, the\r |
950 | zlib error is Z_MEM_ERROR). */\r |
951 | \r |
952 | ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));\r |
953 | /*\r |
954 | gzdopen() associates a gzFile with the file descriptor fd. File\r |
955 | descriptors are obtained from calls like open, dup, creat, pipe or\r |
956 | fileno (in the file has been previously opened with fopen).\r |
957 | The mode parameter is as in gzopen.\r |
958 | The next call of gzclose on the returned gzFile will also close the\r |
959 | file descriptor fd, just like fclose(fdopen(fd), mode) closes the file\r |
960 | descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).\r |
961 | gzdopen returns NULL if there was insufficient memory to allocate\r |
962 | the (de)compression state.\r |
963 | */\r |
964 | \r |
965 | ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));\r |
966 | /*\r |
967 | Dynamically update the compression level or strategy. See the description\r |
968 | of deflateInit2 for the meaning of these parameters.\r |
969 | gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not\r |
970 | opened for writing.\r |
971 | */\r |
972 | \r |
973 | ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));\r |
974 | /*\r |
975 | Reads the given number of uncompressed bytes from the compressed file.\r |
976 | If the input file was not in gzip format, gzread copies the given number\r |
977 | of bytes into the buffer.\r |
978 | gzread returns the number of uncompressed bytes actually read (0 for\r |
979 | end of file, -1 for error). */\r |
980 | \r |
981 | ZEXTERN int ZEXPORT gzwrite OF((gzFile file,\r |
982 | voidpc buf, unsigned len));\r |
983 | /*\r |
984 | Writes the given number of uncompressed bytes into the compressed file.\r |
985 | gzwrite returns the number of uncompressed bytes actually written\r |
986 | (0 in case of error).\r |
987 | */\r |
988 | \r |
989 | ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));\r |
990 | /*\r |
991 | Converts, formats, and writes the args to the compressed file under\r |
992 | control of the format string, as in fprintf. gzprintf returns the number of\r |
993 | uncompressed bytes actually written (0 in case of error). The number of\r |
994 | uncompressed bytes written is limited to 4095. The caller should assure that\r |
995 | this limit is not exceeded. If it is exceeded, then gzprintf() will return\r |
996 | return an error (0) with nothing written. In this case, there may also be a\r |
997 | buffer overflow with unpredictable consequences, which is possible only if\r |
998 | zlib was compiled with the insecure functions sprintf() or vsprintf()\r |
999 | because the secure snprintf() or vsnprintf() functions were not available.\r |
1000 | */\r |
1001 | \r |
1002 | ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));\r |
1003 | /*\r |
1004 | Writes the given null-terminated string to the compressed file, excluding\r |
1005 | the terminating null character.\r |
1006 | gzputs returns the number of characters written, or -1 in case of error.\r |
1007 | */\r |
1008 | \r |
1009 | ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));\r |
1010 | /*\r |
1011 | Reads bytes from the compressed file until len-1 characters are read, or\r |
1012 | a newline character is read and transferred to buf, or an end-of-file\r |
1013 | condition is encountered. The string is then terminated with a null\r |
1014 | character.\r |
1015 | gzgets returns buf, or Z_NULL in case of error.\r |
1016 | */\r |
1017 | \r |
1018 | ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));\r |
1019 | /*\r |
1020 | Writes c, converted to an unsigned char, into the compressed file.\r |
1021 | gzputc returns the value that was written, or -1 in case of error.\r |
1022 | */\r |
1023 | \r |
1024 | ZEXTERN int ZEXPORT gzgetc OF((gzFile file));\r |
1025 | /*\r |
1026 | Reads one byte from the compressed file. gzgetc returns this byte\r |
1027 | or -1 in case of end of file or error.\r |
1028 | */\r |
1029 | \r |
1030 | ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));\r |
1031 | /*\r |
1032 | Push one character back onto the stream to be read again later.\r |
1033 | Only one character of push-back is allowed. gzungetc() returns the\r |
1034 | character pushed, or -1 on failure. gzungetc() will fail if a\r |
1035 | character has been pushed but not read yet, or if c is -1. The pushed\r |
1036 | character will be discarded if the stream is repositioned with gzseek()\r |
1037 | or gzrewind().\r |
1038 | */\r |
1039 | \r |
1040 | ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));\r |
1041 | /*\r |
1042 | Flushes all pending output into the compressed file. The parameter\r |
1043 | flush is as in the deflate() function. The return value is the zlib\r |
1044 | error number (see function gzerror below). gzflush returns Z_OK if\r |
1045 | the flush parameter is Z_FINISH and all output could be flushed.\r |
1046 | gzflush should be called only when strictly necessary because it can\r |
1047 | degrade compression.\r |
1048 | */\r |
1049 | \r |
1050 | ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,\r |
1051 | z_off_t offset, int whence));\r |
1052 | /*\r |
1053 | Sets the starting position for the next gzread or gzwrite on the\r |
1054 | given compressed file. The offset represents a number of bytes in the\r |
1055 | uncompressed data stream. The whence parameter is defined as in lseek(2);\r |
1056 | the value SEEK_END is not supported.\r |
1057 | If the file is opened for reading, this function is emulated but can be\r |
1058 | extremely slow. If the file is opened for writing, only forward seeks are\r |
1059 | supported; gzseek then compresses a sequence of zeroes up to the new\r |
1060 | starting position.\r |
1061 | \r |
1062 | gzseek returns the resulting offset location as measured in bytes from\r |
1063 | the beginning of the uncompressed stream, or -1 in case of error, in\r |
1064 | particular if the file is opened for writing and the new starting position\r |
1065 | would be before the current position.\r |
1066 | */\r |
1067 | \r |
1068 | ZEXTERN int ZEXPORT gzrewind OF((gzFile file));\r |
1069 | /*\r |
1070 | Rewinds the given file. This function is supported only for reading.\r |
1071 | \r |
1072 | gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)\r |
1073 | */\r |
1074 | \r |
1075 | ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));\r |
1076 | /*\r |
1077 | Returns the starting position for the next gzread or gzwrite on the\r |
1078 | given compressed file. This position represents a number of bytes in the\r |
1079 | uncompressed data stream.\r |
1080 | \r |
1081 | gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)\r |
1082 | */\r |
1083 | \r |
1084 | ZEXTERN int ZEXPORT gzeof OF((gzFile file));\r |
1085 | /*\r |
1086 | Returns 1 when EOF has previously been detected reading the given\r |
1087 | input stream, otherwise zero.\r |
1088 | */\r |
1089 | \r |
1090 | ZEXTERN int ZEXPORT gzclose OF((gzFile file));\r |
1091 | /*\r |
1092 | Flushes all pending output if necessary, closes the compressed file\r |
1093 | and deallocates all the (de)compression state. The return value is the zlib\r |
1094 | error number (see function gzerror below).\r |
1095 | */\r |
1096 | \r |
1097 | ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));\r |
1098 | /*\r |
1099 | Returns the error message for the last error which occurred on the\r |
1100 | given compressed file. errnum is set to zlib error number. If an\r |
1101 | error occurred in the file system and not in the compression library,\r |
1102 | errnum is set to Z_ERRNO and the application may consult errno\r |
1103 | to get the exact error code.\r |
1104 | */\r |
1105 | \r |
1106 | ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));\r |
1107 | /*\r |
1108 | Clears the error and end-of-file flags for file. This is analogous to the\r |
1109 | clearerr() function in stdio. This is useful for continuing to read a gzip\r |
1110 | file that is being written concurrently.\r |
1111 | */\r |
1112 | \r |
1113 | /* checksum functions */\r |
1114 | \r |
1115 | /*\r |
1116 | These functions are not related to compression but are exported\r |
1117 | anyway because they might be useful in applications using the\r |
1118 | compression library.\r |
1119 | */\r |
1120 | \r |
1121 | ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));\r |
1122 | \r |
1123 | /*\r |
1124 | Update a running Adler-32 checksum with the bytes buf[0..len-1] and\r |
1125 | return the updated checksum. If buf is NULL, this function returns\r |
1126 | the required initial value for the checksum.\r |
1127 | An Adler-32 checksum is almost as reliable as a CRC32 but can be computed\r |
1128 | much faster. Usage example:\r |
1129 | \r |
1130 | uLong adler = adler32(0L, Z_NULL, 0);\r |
1131 | \r |
1132 | while (read_buffer(buffer, length) != EOF) {\r |
1133 | adler = adler32(adler, buffer, length);\r |
1134 | }\r |
1135 | if (adler != original_adler) error();\r |
1136 | */\r |
1137 | \r |
1138 | ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));\r |
1139 | /*\r |
1140 | Update a running crc with the bytes buf[0..len-1] and return the updated\r |
1141 | crc. If buf is NULL, this function returns the required initial value\r |
1142 | for the crc. Pre- and post-conditioning (one's complement) is performed\r |
1143 | within this function so it shouldn't be done by the application.\r |
1144 | Usage example:\r |
1145 | \r |
1146 | uLong crc = crc32(0L, Z_NULL, 0);\r |
1147 | \r |
1148 | while (read_buffer(buffer, length) != EOF) {\r |
1149 | crc = crc32(crc, buffer, length);\r |
1150 | }\r |
1151 | if (crc != original_crc) error();\r |
1152 | */\r |
1153 | \r |
1154 | \r |
1155 | /* various hacks, don't look :) */\r |
1156 | \r |
1157 | /* deflateInit and inflateInit are macros to allow checking the zlib version\r |
1158 | * and the compiler's view of z_stream:\r |
1159 | */\r |
1160 | ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,\r |
1161 | const char *version, int stream_size));\r |
1162 | ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,\r |
1163 | const char *version, int stream_size));\r |
1164 | ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,\r |
1165 | int windowBits, int memLevel,\r |
1166 | int strategy, const char *version,\r |
1167 | int stream_size));\r |
1168 | ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,\r |
1169 | const char *version, int stream_size));\r |
1170 | ZEXTERN int ZEXPORT inflateBackInit_ OF((z_stream FAR *strm, int windowBits,\r |
1171 | unsigned char FAR *window,\r |
1172 | const char *version,\r |
1173 | int stream_size));\r |
1174 | #define deflateInit(strm, level) \\r |
1175 | deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))\r |
1176 | #define inflateInit(strm) \\r |
1177 | inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))\r |
1178 | #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \\r |
1179 | deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\\r |
1180 | (strategy), ZLIB_VERSION, sizeof(z_stream))\r |
1181 | #define inflateInit2(strm, windowBits) \\r |
1182 | inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))\r |
1183 | #define inflateBackInit(strm, windowBits, window) \\r |
1184 | inflateBackInit_((strm), (windowBits), (window), \\r |
1185 | ZLIB_VERSION, sizeof(z_stream))\r |
1186 | \r |
1187 | \r |
1188 | #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)\r |
1189 | struct internal_state {int dummy;}; /* hack for buggy compilers */\r |
1190 | #endif\r |
1191 | \r |
1192 | ZEXTERN const char * ZEXPORT zError OF((int err));\r |
1193 | ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z));\r |
1194 | ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));\r |
1195 | \r |
1196 | #ifdef __cplusplus\r |
1197 | }\r |
1198 | #endif\r |
1199 | \r |
1200 | #endif /* ZLIB_H */\r |