1 | /* |
2 | * Copyright (c) 2008 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
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10 | * may not be used to create, or enable the creation or redistribution of, |
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12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
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26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | /* zlib.h -- interface of the 'zlib' general purpose compression library |
29 | version 1.2.3, July 18th, 2005 |
30 | |
31 | Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler |
32 | |
33 | This software is provided 'as-is', without any express or implied |
34 | warranty. In no event will the authors be held liable for any damages |
35 | arising from the use of this software. |
36 | |
37 | Permission is granted to anyone to use this software for any purpose, |
38 | including commercial applications, and to alter it and redistribute it |
39 | freely, subject to the following restrictions: |
40 | |
41 | 1. The origin of this software must not be misrepresented; you must not |
42 | claim that you wrote the original software. If you use this software |
43 | in a product, an acknowledgment in the product documentation would be |
44 | appreciated but is not required. |
45 | 2. Altered source versions must be plainly marked as such, and must not be |
46 | misrepresented as being the original software. |
47 | 3. This notice may not be removed or altered from any source distribution. |
48 | |
49 | Jean-loup Gailly Mark Adler |
50 | jloup@gzip.org madler@alumni.caltech.edu |
51 | |
52 | |
53 | The data format used by the zlib library is described by RFCs (Request for |
54 | Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt |
55 | (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). |
56 | */ |
57 | |
58 | #ifndef ZLIB_H |
59 | #define ZLIB_H |
60 | |
61 | #ifdef __cplusplus |
62 | extern "C" { |
63 | #endif |
64 | |
65 | #include "zconf.h" |
66 | |
67 | #define ZLIB_VERSION "1.2.3" |
68 | #define ZLIB_VERNUM 0x1230 |
69 | |
70 | /* |
71 | The 'zlib' compression library provides in-memory compression and |
72 | decompression functions, including integrity checks of the uncompressed |
73 | data. This version of the library supports only one compression method |
74 | (deflation) but other algorithms will be added later and will have the same |
75 | stream interface. |
76 | |
77 | Compression can be done in a single step if the buffers are large |
78 | enough (for example if an input file is mmap'ed), or can be done by |
79 | repeated calls of the compression function. In the latter case, the |
80 | application must provide more input and/or consume the output |
81 | (providing more output space) before each call. |
82 | |
83 | The compressed data format used by default by the in-memory functions is |
84 | the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped |
85 | around a deflate stream, which is itself documented in RFC 1951. |
86 | |
87 | The library also supports reading and writing files in gzip (.gz) format |
88 | with an interface similar to that of stdio using the functions that start |
89 | with "gz". The gzip format is different from the zlib format. gzip is a |
90 | gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. |
91 | |
92 | This library can optionally read and write gzip streams in memory as well. |
93 | |
94 | The zlib format was designed to be compact and fast for use in memory |
95 | and on communications channels. The gzip format was designed for single- |
96 | file compression on file systems, has a larger header than zlib to maintain |
97 | directory information, and uses a different, slower check method than zlib. |
98 | |
99 | The library does not install any signal handler. The decoder checks |
100 | the consistency of the compressed data, so the library should never |
101 | crash even in case of corrupted input. |
102 | */ |
103 | |
104 | typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); |
105 | typedef void (*free_func) OF((voidpf opaque, voidpf address)); |
106 | |
107 | struct internal_state; |
108 | |
109 | typedef struct z_stream_s { |
110 | Bytef *next_in; /* next input byte */ |
111 | uInt avail_in; /* number of bytes available at next_in */ |
112 | uLong total_in; /* total nb of input bytes read so far */ |
113 | |
114 | Bytef *next_out; /* next output byte should be put there */ |
115 | uInt avail_out; /* remaining free space at next_out */ |
116 | uLong total_out; /* total nb of bytes output so far */ |
117 | |
118 | char *msg; /* last error message, NULL if no error */ |
119 | struct internal_state FAR *state; /* not visible by applications */ |
120 | |
121 | alloc_func zalloc; /* used to allocate the internal state */ |
122 | free_func zfree; /* used to free the internal state */ |
123 | voidpf opaque; /* private data object passed to zalloc and zfree */ |
124 | |
125 | int data_type; /* best guess about the data type: binary or text */ |
126 | uLong adler; /* adler32 value of the uncompressed data */ |
127 | uLong reserved; /* reserved for future use */ |
128 | } z_stream; |
129 | |
130 | typedef z_stream FAR *z_streamp; |
131 | |
132 | /* |
133 | gzip header information passed to and from zlib routines. See RFC 1952 |
134 | for more details on the meanings of these fields. |
135 | */ |
136 | typedef struct { |
137 | int ; /* true if compressed data believed to be text */ |
138 | uLong ; /* modification time */ |
139 | int ; /* extra flags (not used when writing a gzip file) */ |
140 | int ; /* operating system */ |
141 | Bytef *; /* pointer to extra field or Z_NULL if none */ |
142 | uInt ; /* extra field length (valid if extra != Z_NULL) */ |
143 | uInt ; /* space at extra (only when reading header) */ |
144 | Bytef *; /* pointer to zero-terminated file name or Z_NULL */ |
145 | uInt ; /* space at name (only when reading header) */ |
146 | Bytef *; /* pointer to zero-terminated comment or Z_NULL */ |
147 | uInt ; /* space at comment (only when reading header) */ |
148 | int ; /* true if there was or will be a header crc */ |
149 | int ; /* true when done reading gzip header (not used |
150 | when writing a gzip file) */ |
151 | } ; |
152 | |
153 | typedef gz_header FAR *; |
154 | |
155 | /* |
156 | The application must update next_in and avail_in when avail_in has |
157 | dropped to zero. It must update next_out and avail_out when avail_out |
158 | has dropped to zero. The application must initialize zalloc, zfree and |
159 | opaque before calling the init function. All other fields are set by the |
160 | compression library and must not be updated by the application. |
161 | |
162 | The opaque value provided by the application will be passed as the first |
163 | parameter for calls of zalloc and zfree. This can be useful for custom |
164 | memory management. The compression library attaches no meaning to the |
165 | opaque value. |
166 | |
167 | zalloc must return Z_NULL if there is not enough memory for the object. |
168 | If zlib is used in a multi-threaded application, zalloc and zfree must be |
169 | thread safe. |
170 | |
171 | On 16-bit systems, the functions zalloc and zfree must be able to allocate |
172 | exactly 65536 bytes, but will not be required to allocate more than this |
173 | if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, |
174 | pointers returned by zalloc for objects of exactly 65536 bytes *must* |
175 | have their offset normalized to zero. The default allocation function |
176 | provided by this library ensures this (see zutil.c). To reduce memory |
177 | requirements and avoid any allocation of 64K objects, at the expense of |
178 | compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). |
179 | |
180 | The fields total_in and total_out can be used for statistics or |
181 | progress reports. After compression, total_in holds the total size of |
182 | the uncompressed data and may be saved for use in the decompressor |
183 | (particularly if the decompressor wants to decompress everything in |
184 | a single step). |
185 | */ |
186 | |
187 | /* constants */ |
188 | |
189 | #define Z_NO_FLUSH 0 |
190 | #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ |
191 | /* 2 is a reserved value (in zlib 1.2.3, Z_PACKET_FLUSH was removed) */ |
192 | #define Z_SYNC_FLUSH 3 |
193 | #define Z_FULL_FLUSH 4 |
194 | #define Z_FINISH 5 |
195 | #define Z_BLOCK 6 |
196 | |
197 | /* Allowed flush values; see deflate() and inflate() below for details */ |
198 | |
199 | #define Z_OK 0 |
200 | #define Z_STREAM_END 1 |
201 | #define Z_NEED_DICT 2 |
202 | #define Z_ERRNO (-1) |
203 | #define Z_STREAM_ERROR (-2) |
204 | #define Z_DATA_ERROR (-3) |
205 | #define Z_MEM_ERROR (-4) |
206 | #define Z_BUF_ERROR (-5) |
207 | #define Z_VERSION_ERROR (-6) |
208 | /* Return codes for the compression/decompression functions. Negative |
209 | * values are errors, positive values are used for special but normal events. |
210 | */ |
211 | |
212 | #define Z_NO_COMPRESSION 0 |
213 | #define Z_BEST_SPEED 1 |
214 | #define Z_BEST_COMPRESSION 9 |
215 | #define Z_DEFAULT_COMPRESSION (-1) |
216 | /* compression levels */ |
217 | |
218 | #define Z_FILTERED 1 |
219 | #define Z_HUFFMAN_ONLY 2 |
220 | #define Z_RLE 3 |
221 | #define Z_FIXED 4 |
222 | #define Z_DEFAULT_STRATEGY 0 |
223 | /* compression strategy; see deflateInit2() below for details */ |
224 | |
225 | #define Z_BINARY 0 |
226 | #define Z_TEXT 1 |
227 | #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ |
228 | #define Z_UNKNOWN 2 |
229 | /* Possible values of the data_type field (though see inflate()) */ |
230 | |
231 | #define Z_DEFLATED 8 |
232 | /* The deflate compression method (the only one supported in this version) */ |
233 | |
234 | #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ |
235 | |
236 | #define zlib_version zlibVersion() |
237 | /* for compatibility with versions < 1.0.2 */ |
238 | |
239 | /* basic functions */ |
240 | |
241 | ZEXTERN const char * ZEXPORT zlibVersion OF((void)); |
242 | /* The application can compare zlibVersion and ZLIB_VERSION for consistency. |
243 | If the first character differs, the library code actually used is |
244 | not compatible with the zlib.h header file used by the application. |
245 | This check is automatically made by deflateInit and inflateInit. |
246 | */ |
247 | |
248 | /* |
249 | ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); |
250 | |
251 | Initializes the internal stream state for compression. The fields |
252 | zalloc, zfree and opaque must be initialized before by the caller. |
253 | If zalloc and zfree are set to Z_NULL, deflateInit updates them to |
254 | use default allocation functions. |
255 | |
256 | The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: |
257 | 1 gives best speed, 9 gives best compression, 0 gives no compression at |
258 | all (the input data is simply copied a block at a time). |
259 | Z_DEFAULT_COMPRESSION requests a default compromise between speed and |
260 | compression (currently equivalent to level 6). |
261 | |
262 | deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not |
263 | enough memory, Z_STREAM_ERROR if level is not a valid compression level, |
264 | Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible |
265 | with the version assumed by the caller (ZLIB_VERSION). |
266 | msg is set to null if there is no error message. deflateInit does not |
267 | perform any compression: this will be done by deflate(). |
268 | */ |
269 | |
270 | |
271 | ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); |
272 | /* |
273 | deflate compresses as much data as possible, and stops when the input |
274 | buffer becomes empty or the output buffer becomes full. It may introduce some |
275 | output latency (reading input without producing any output) except when |
276 | forced to flush. |
277 | |
278 | The detailed semantics are as follows. deflate performs one or both of the |
279 | following actions: |
280 | |
281 | - Compress more input starting at next_in and update next_in and avail_in |
282 | accordingly. If not all input can be processed (because there is not |
283 | enough room in the output buffer), next_in and avail_in are updated and |
284 | processing will resume at this point for the next call of deflate(). |
285 | |
286 | - Provide more output starting at next_out and update next_out and avail_out |
287 | accordingly. This action is forced if the parameter flush is non zero. |
288 | Forcing flush frequently degrades the compression ratio, so this parameter |
289 | should be set only when necessary (in interactive applications). |
290 | Some output may be provided even if flush is not set. |
291 | |
292 | Before the call of deflate(), the application should ensure that at least |
293 | one of the actions is possible, by providing more input and/or consuming |
294 | more output, and updating avail_in or avail_out accordingly; avail_out |
295 | should never be zero before the call. The application can consume the |
296 | compressed output when it wants, for example when the output buffer is full |
297 | (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK |
298 | and with zero avail_out, it must be called again after making room in the |
299 | output buffer because there might be more output pending. |
300 | |
301 | Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to |
302 | decide how much data to accumualte before producing output, in order to |
303 | maximize compression. |
304 | |
305 | If the parameter flush is set to Z_SYNC_FLUSH, all pending output is |
306 | flushed to the output buffer and the output is aligned on a byte boundary, so |
307 | that the decompressor can get all input data available so far. (In particular |
308 | avail_in is zero after the call if enough output space has been provided |
309 | before the call.) Flushing may degrade compression for some compression |
310 | algorithms and so it should be used only when necessary. |
311 | |
312 | If flush is set to Z_FULL_FLUSH, all output is flushed as with |
313 | Z_SYNC_FLUSH, and the compression state is reset so that decompression can |
314 | restart from this point if previous compressed data has been damaged or if |
315 | random access is desired. Using Z_FULL_FLUSH too often can seriously degrade |
316 | compression. |
317 | |
318 | If deflate returns with avail_out == 0, this function must be called again |
319 | with the same value of the flush parameter and more output space (updated |
320 | avail_out), until the flush is complete (deflate returns with non-zero |
321 | avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that |
322 | avail_out is greater than six to avoid repeated flush markers due to |
323 | avail_out == 0 on return. |
324 | |
325 | If the parameter flush is set to Z_FINISH, pending input is processed, |
326 | pending output is flushed and deflate returns with Z_STREAM_END if there |
327 | was enough output space; if deflate returns with Z_OK, this function must be |
328 | called again with Z_FINISH and more output space (updated avail_out) but no |
329 | more input data, until it returns with Z_STREAM_END or an error. After |
330 | deflate has returned Z_STREAM_END, the only possible operations on the |
331 | stream are deflateReset or deflateEnd. |
332 | |
333 | Z_FINISH can be used immediately after deflateInit if all the compression |
334 | is to be done in a single step. In this case, avail_out must be at least |
335 | the value returned by deflateBound (see below). If deflate does not return |
336 | Z_STREAM_END, then it must be called again as described above. |
337 | |
338 | deflate() sets strm->adler to the adler32 checksum of all input read |
339 | so far (that is, total_in bytes). |
340 | |
341 | deflate() may update strm->data_type if it can make a good guess about |
342 | the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered |
343 | binary. This field is only for information purposes and does not affect |
344 | the compression algorithm in any manner. |
345 | |
346 | deflate() returns Z_OK if some progress has been made (more input |
347 | processed or more output produced), Z_STREAM_END if all input has been |
348 | consumed and all output has been produced (only when flush is set to |
349 | Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example |
350 | if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible |
351 | (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not |
352 | fatal, and deflate() can be called again with more input and more output |
353 | space to continue compressing. |
354 | */ |
355 | |
356 | |
357 | ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); |
358 | /* |
359 | All dynamically allocated data structures for this stream are freed. |
360 | This function discards any unprocessed input and does not flush any |
361 | pending output. |
362 | |
363 | deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the |
364 | stream state was inconsistent, Z_DATA_ERROR if the stream was freed |
365 | prematurely (some input or output was discarded). In the error case, |
366 | msg may be set but then points to a static string (which must not be |
367 | deallocated). |
368 | */ |
369 | |
370 | |
371 | /* |
372 | ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); |
373 | |
374 | Initializes the internal stream state for decompression. The fields |
375 | next_in, avail_in, zalloc, zfree and opaque must be initialized before by |
376 | the caller. If next_in is not Z_NULL and avail_in is large enough (the exact |
377 | value depends on the compression method), inflateInit determines the |
378 | compression method from the zlib header and allocates all data structures |
379 | accordingly; otherwise the allocation will be deferred to the first call of |
380 | inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to |
381 | use default allocation functions. |
382 | |
383 | inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough |
384 | memory, Z_VERSION_ERROR if the zlib library version is incompatible with the |
385 | version assumed by the caller. msg is set to null if there is no error |
386 | message. inflateInit does not perform any decompression apart from reading |
387 | the zlib header if present: this will be done by inflate(). (So next_in and |
388 | avail_in may be modified, but next_out and avail_out are unchanged.) |
389 | */ |
390 | |
391 | |
392 | ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); |
393 | /* |
394 | inflate decompresses as much data as possible, and stops when the input |
395 | buffer becomes empty or the output buffer becomes full. It may introduce |
396 | some output latency (reading input without producing any output) except when |
397 | forced to flush. |
398 | |
399 | The detailed semantics are as follows. inflate performs one or both of the |
400 | following actions: |
401 | |
402 | - Decompress more input starting at next_in and update next_in and avail_in |
403 | accordingly. If not all input can be processed (because there is not |
404 | enough room in the output buffer), next_in is updated and processing |
405 | will resume at this point for the next call of inflate(). |
406 | |
407 | - Provide more output starting at next_out and update next_out and avail_out |
408 | accordingly. inflate() provides as much output as possible, until there |
409 | is no more input data or no more space in the output buffer (see below |
410 | about the flush parameter). |
411 | |
412 | Before the call of inflate(), the application should ensure that at least |
413 | one of the actions is possible, by providing more input and/or consuming |
414 | more output, and updating the next_* and avail_* values accordingly. |
415 | The application can consume the uncompressed output when it wants, for |
416 | example when the output buffer is full (avail_out == 0), or after each |
417 | call of inflate(). If inflate returns Z_OK and with zero avail_out, it |
418 | must be called again after making room in the output buffer because there |
419 | might be more output pending. |
420 | |
421 | The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, |
422 | Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much |
423 | output as possible to the output buffer. Z_BLOCK requests that inflate() stop |
424 | if and when it gets to the next deflate block boundary. When decoding the |
425 | zlib or gzip format, this will cause inflate() to return immediately after |
426 | the header and before the first block. When doing a raw inflate, inflate() |
427 | will go ahead and process the first block, and will return when it gets to |
428 | the end of that block, or when it runs out of data. |
429 | |
430 | The Z_BLOCK option assists in appending to or combining deflate streams. |
431 | Also to assist in this, on return inflate() will set strm->data_type to the |
432 | number of unused bits in the last byte taken from strm->next_in, plus 64 |
433 | if inflate() is currently decoding the last block in the deflate stream, |
434 | plus 128 if inflate() returned immediately after decoding an end-of-block |
435 | code or decoding the complete header up to just before the first byte of the |
436 | deflate stream. The end-of-block will not be indicated until all of the |
437 | uncompressed data from that block has been written to strm->next_out. The |
438 | number of unused bits may in general be greater than seven, except when |
439 | bit 7 of data_type is set, in which case the number of unused bits will be |
440 | less than eight. |
441 | |
442 | inflate() should normally be called until it returns Z_STREAM_END or an |
443 | error. However if all decompression is to be performed in a single step |
444 | (a single call of inflate), the parameter flush should be set to |
445 | Z_FINISH. In this case all pending input is processed and all pending |
446 | output is flushed; avail_out must be large enough to hold all the |
447 | uncompressed data. (The size of the uncompressed data may have been saved |
448 | by the compressor for this purpose.) The next operation on this stream must |
449 | be inflateEnd to deallocate the decompression state. The use of Z_FINISH |
450 | is never required, but can be used to inform inflate that a faster approach |
451 | may be used for the single inflate() call. |
452 | |
453 | In this implementation, inflate() always flushes as much output as |
454 | possible to the output buffer, and always uses the faster approach on the |
455 | first call. So the only effect of the flush parameter in this implementation |
456 | is on the return value of inflate(), as noted below, or when it returns early |
457 | because Z_BLOCK is used. |
458 | |
459 | If a preset dictionary is needed after this call (see inflateSetDictionary |
460 | below), inflate sets strm->adler to the adler32 checksum of the dictionary |
461 | chosen by the compressor and returns Z_NEED_DICT; otherwise it sets |
462 | strm->adler to the adler32 checksum of all output produced so far (that is, |
463 | total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described |
464 | below. At the end of the stream, inflate() checks that its computed adler32 |
465 | checksum is equal to that saved by the compressor and returns Z_STREAM_END |
466 | only if the checksum is correct. |
467 | |
468 | inflate() will decompress and check either zlib-wrapped or gzip-wrapped |
469 | deflate data. The header type is detected automatically. Any information |
470 | contained in the gzip header is not retained, so applications that need that |
471 | information should instead use raw inflate, see inflateInit2() below, or |
472 | inflateBack() and perform their own processing of the gzip header and |
473 | trailer. |
474 | |
475 | inflate() returns Z_OK if some progress has been made (more input processed |
476 | or more output produced), Z_STREAM_END if the end of the compressed data has |
477 | been reached and all uncompressed output has been produced, Z_NEED_DICT if a |
478 | preset dictionary is needed at this point, Z_DATA_ERROR if the input data was |
479 | corrupted (input stream not conforming to the zlib format or incorrect check |
480 | value), Z_STREAM_ERROR if the stream structure was inconsistent (for example |
481 | if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, |
482 | Z_BUF_ERROR if no progress is possible or if there was not enough room in the |
483 | output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and |
484 | inflate() can be called again with more input and more output space to |
485 | continue decompressing. If Z_DATA_ERROR is returned, the application may then |
486 | call inflateSync() to look for a good compression block if a partial recovery |
487 | of the data is desired. |
488 | */ |
489 | |
490 | |
491 | ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); |
492 | /* |
493 | All dynamically allocated data structures for this stream are freed. |
494 | This function discards any unprocessed input and does not flush any |
495 | pending output. |
496 | |
497 | inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state |
498 | was inconsistent. In the error case, msg may be set but then points to a |
499 | static string (which must not be deallocated). |
500 | */ |
501 | |
502 | /* Advanced functions */ |
503 | |
504 | /* |
505 | The following functions are needed only in some special applications. |
506 | */ |
507 | |
508 | /* |
509 | ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, |
510 | int level, |
511 | int method, |
512 | int windowBits, |
513 | int memLevel, |
514 | int strategy)); |
515 | |
516 | This is another version of deflateInit with more compression options. The |
517 | fields next_in, zalloc, zfree and opaque must be initialized before by |
518 | the caller. |
519 | |
520 | The method parameter is the compression method. It must be Z_DEFLATED in |
521 | this version of the library. |
522 | |
523 | The windowBits parameter is the base two logarithm of the window size |
524 | (the size of the history buffer). It should be in the range 8..15 for this |
525 | version of the library. Larger values of this parameter result in better |
526 | compression at the expense of memory usage. The default value is 15 if |
527 | deflateInit is used instead. |
528 | |
529 | windowBits can also be -8..-15 for raw deflate. In this case, -windowBits |
530 | determines the window size. deflate() will then generate raw deflate data |
531 | with no zlib header or trailer, and will not compute an adler32 check value. |
532 | |
533 | windowBits can also be greater than 15 for optional gzip encoding. Add |
534 | 16 to windowBits to write a simple gzip header and trailer around the |
535 | compressed data instead of a zlib wrapper. The gzip header will have no |
536 | file name, no extra data, no comment, no modification time (set to zero), |
537 | no header crc, and the operating system will be set to 255 (unknown). If a |
538 | gzip stream is being written, strm->adler is a crc32 instead of an adler32. |
539 | |
540 | The memLevel parameter specifies how much memory should be allocated |
541 | for the internal compression state. memLevel=1 uses minimum memory but |
542 | is slow and reduces compression ratio; memLevel=9 uses maximum memory |
543 | for optimal speed. The default value is 8. See zconf.h for total memory |
544 | usage as a function of windowBits and memLevel. |
545 | |
546 | The strategy parameter is used to tune the compression algorithm. Use the |
547 | value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a |
548 | filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no |
549 | string match), or Z_RLE to limit match distances to one (run-length |
550 | encoding). Filtered data consists mostly of small values with a somewhat |
551 | random distribution. In this case, the compression algorithm is tuned to |
552 | compress them better. The effect of Z_FILTERED is to force more Huffman |
553 | coding and less string matching; it is somewhat intermediate between |
554 | Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as |
555 | Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy |
556 | parameter only affects the compression ratio but not the correctness of the |
557 | compressed output even if it is not set appropriately. Z_FIXED prevents the |
558 | use of dynamic Huffman codes, allowing for a simpler decoder for special |
559 | applications. |
560 | |
561 | deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
562 | memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid |
563 | method). msg is set to null if there is no error message. deflateInit2 does |
564 | not perform any compression: this will be done by deflate(). |
565 | */ |
566 | |
567 | ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, |
568 | const Bytef *dictionary, |
569 | uInt dictLength)); |
570 | /* |
571 | Initializes the compression dictionary from the given byte sequence |
572 | without producing any compressed output. This function must be called |
573 | immediately after deflateInit, deflateInit2 or deflateReset, before any |
574 | call of deflate. The compressor and decompressor must use exactly the same |
575 | dictionary (see inflateSetDictionary). |
576 | |
577 | The dictionary should consist of strings (byte sequences) that are likely |
578 | to be encountered later in the data to be compressed, with the most commonly |
579 | used strings preferably put towards the end of the dictionary. Using a |
580 | dictionary is most useful when the data to be compressed is short and can be |
581 | predicted with good accuracy; the data can then be compressed better than |
582 | with the default empty dictionary. |
583 | |
584 | Depending on the size of the compression data structures selected by |
585 | deflateInit or deflateInit2, a part of the dictionary may in effect be |
586 | discarded, for example if the dictionary is larger than the window size in |
587 | deflate or deflate2. Thus the strings most likely to be useful should be |
588 | put at the end of the dictionary, not at the front. In addition, the |
589 | current implementation of deflate will use at most the window size minus |
590 | 262 bytes of the provided dictionary. |
591 | |
592 | Upon return of this function, strm->adler is set to the adler32 value |
593 | of the dictionary; the decompressor may later use this value to determine |
594 | which dictionary has been used by the compressor. (The adler32 value |
595 | applies to the whole dictionary even if only a subset of the dictionary is |
596 | actually used by the compressor.) If a raw deflate was requested, then the |
597 | adler32 value is not computed and strm->adler is not set. |
598 | |
599 | deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a |
600 | parameter is invalid (such as NULL dictionary) or the stream state is |
601 | inconsistent (for example if deflate has already been called for this stream |
602 | or if the compression method is bsort). deflateSetDictionary does not |
603 | perform any compression: this will be done by deflate(). |
604 | */ |
605 | |
606 | ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, |
607 | z_streamp source)); |
608 | /* |
609 | Sets the destination stream as a complete copy of the source stream. |
610 | |
611 | This function can be useful when several compression strategies will be |
612 | tried, for example when there are several ways of pre-processing the input |
613 | data with a filter. The streams that will be discarded should then be freed |
614 | by calling deflateEnd. Note that deflateCopy duplicates the internal |
615 | compression state which can be quite large, so this strategy is slow and |
616 | can consume lots of memory. |
617 | |
618 | deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not |
619 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent |
620 | (such as zalloc being NULL). msg is left unchanged in both source and |
621 | destination. |
622 | */ |
623 | |
624 | #if XNU_KERNEL_PRIVATE |
625 | |
626 | typedef int (*z_input_func) (z_streamp strm, Bytef *buf, unsigned size); |
627 | typedef int (*z_output_func)(z_streamp strm, Bytef *buf, unsigned size); |
628 | |
629 | ZEXTERN int ZEXPORT deflateResetWithIO(z_streamp strm, z_input_func zinput, z_output_func zoutput); |
630 | |
631 | #endif /* XNU_KERNEL_PRIVATE */ |
632 | |
633 | ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); |
634 | /* |
635 | This function is equivalent to deflateEnd followed by deflateInit, |
636 | but does not free and reallocate all the internal compression state. |
637 | The stream will keep the same compression level and any other attributes |
638 | that may have been set by deflateInit2. |
639 | |
640 | deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source |
641 | stream state was inconsistent (such as zalloc or state being NULL). |
642 | */ |
643 | |
644 | ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, |
645 | int level, |
646 | int strategy)); |
647 | /* |
648 | Dynamically update the compression level and compression strategy. The |
649 | interpretation of level and strategy is as in deflateInit2. This can be |
650 | used to switch between compression and straight copy of the input data, or |
651 | to switch to a different kind of input data requiring a different |
652 | strategy. If the compression level is changed, the input available so far |
653 | is compressed with the old level (and may be flushed); the new level will |
654 | take effect only at the next call of deflate(). |
655 | |
656 | Before the call of deflateParams, the stream state must be set as for |
657 | a call of deflate(), since the currently available input may have to |
658 | be compressed and flushed. In particular, strm->avail_out must be non-zero. |
659 | |
660 | deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source |
661 | stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR |
662 | if strm->avail_out was zero. |
663 | */ |
664 | |
665 | ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, |
666 | int good_length, |
667 | int max_lazy, |
668 | int nice_length, |
669 | int max_chain)); |
670 | /* |
671 | Fine tune deflate's internal compression parameters. This should only be |
672 | used by someone who understands the algorithm used by zlib's deflate for |
673 | searching for the best matching string, and even then only by the most |
674 | fanatic optimizer trying to squeeze out the last compressed bit for their |
675 | specific input data. Read the deflate.c source code for the meaning of the |
676 | max_lazy, good_length, nice_length, and max_chain parameters. |
677 | |
678 | deflateTune() can be called after deflateInit() or deflateInit2(), and |
679 | returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. |
680 | */ |
681 | |
682 | ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, |
683 | uLong sourceLen)); |
684 | /* |
685 | deflateBound() returns an upper bound on the compressed size after |
686 | deflation of sourceLen bytes. It must be called after deflateInit() |
687 | or deflateInit2(). This would be used to allocate an output buffer |
688 | for deflation in a single pass, and so would be called before deflate(). |
689 | */ |
690 | |
691 | ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, |
692 | int bits, |
693 | int value)); |
694 | /* |
695 | deflatePrime() inserts bits in the deflate output stream. The intent |
696 | is that this function is used to start off the deflate output with the |
697 | bits leftover from a previous deflate stream when appending to it. As such, |
698 | this function can only be used for raw deflate, and must be used before the |
699 | first deflate() call after a deflateInit2() or deflateReset(). bits must be |
700 | less than or equal to 16, and that many of the least significant bits of |
701 | value will be inserted in the output. |
702 | |
703 | deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source |
704 | stream state was inconsistent. |
705 | */ |
706 | |
707 | ZEXTERN int ZEXPORT OF((z_streamp strm, |
708 | gz_headerp head)); |
709 | /* |
710 | deflateSetHeader() provides gzip header information for when a gzip |
711 | stream is requested by deflateInit2(). deflateSetHeader() may be called |
712 | after deflateInit2() or deflateReset() and before the first call of |
713 | deflate(). The text, time, os, extra field, name, and comment information |
714 | in the provided gz_header structure are written to the gzip header (xflag is |
715 | ignored -- the extra flags are set according to the compression level). The |
716 | caller must assure that, if not Z_NULL, name and comment are terminated with |
717 | a zero byte, and that if extra is not Z_NULL, that extra_len bytes are |
718 | available there. If hcrc is true, a gzip header crc is included. Note that |
719 | the current versions of the command-line version of gzip (up through version |
720 | 1.3.x) do not support header crc's, and will report that it is a "multi-part |
721 | gzip file" and give up. |
722 | |
723 | If deflateSetHeader is not used, the default gzip header has text false, |
724 | the time set to zero, and os set to 255, with no extra, name, or comment |
725 | fields. The gzip header is returned to the default state by deflateReset(). |
726 | |
727 | deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source |
728 | stream state was inconsistent. |
729 | */ |
730 | |
731 | /* |
732 | ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, |
733 | int windowBits)); |
734 | |
735 | This is another version of inflateInit with an extra parameter. The |
736 | fields next_in, avail_in, zalloc, zfree and opaque must be initialized |
737 | before by the caller. |
738 | |
739 | The windowBits parameter is the base two logarithm of the maximum window |
740 | size (the size of the history buffer). It should be in the range 8..15 for |
741 | this version of the library. The default value is 15 if inflateInit is used |
742 | instead. windowBits must be greater than or equal to the windowBits value |
743 | provided to deflateInit2() while compressing, or it must be equal to 15 if |
744 | deflateInit2() was not used. If a compressed stream with a larger window |
745 | size is given as input, inflate() will return with the error code |
746 | Z_DATA_ERROR instead of trying to allocate a larger window. |
747 | |
748 | windowBits can also be -8..-15 for raw inflate. In this case, -windowBits |
749 | determines the window size. inflate() will then process raw deflate data, |
750 | not looking for a zlib or gzip header, not generating a check value, and not |
751 | looking for any check values for comparison at the end of the stream. This |
752 | is for use with other formats that use the deflate compressed data format |
753 | such as zip. Those formats provide their own check values. If a custom |
754 | format is developed using the raw deflate format for compressed data, it is |
755 | recommended that a check value such as an adler32 or a crc32 be applied to |
756 | the uncompressed data as is done in the zlib, gzip, and zip formats. For |
757 | most applications, the zlib format should be used as is. Note that comments |
758 | above on the use in deflateInit2() applies to the magnitude of windowBits. |
759 | |
760 | windowBits can also be greater than 15 for optional gzip decoding. Add |
761 | 32 to windowBits to enable zlib and gzip decoding with automatic header |
762 | detection, or add 16 to decode only the gzip format (the zlib format will |
763 | return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is |
764 | a crc32 instead of an adler32. |
765 | |
766 | inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
767 | memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg |
768 | is set to null if there is no error message. inflateInit2 does not perform |
769 | any decompression apart from reading the zlib header if present: this will |
770 | be done by inflate(). (So next_in and avail_in may be modified, but next_out |
771 | and avail_out are unchanged.) |
772 | */ |
773 | |
774 | ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, |
775 | const Bytef *dictionary, |
776 | uInt dictLength)); |
777 | /* |
778 | Initializes the decompression dictionary from the given uncompressed byte |
779 | sequence. This function must be called immediately after a call of inflate, |
780 | if that call returned Z_NEED_DICT. The dictionary chosen by the compressor |
781 | can be determined from the adler32 value returned by that call of inflate. |
782 | The compressor and decompressor must use exactly the same dictionary (see |
783 | deflateSetDictionary). For raw inflate, this function can be called |
784 | immediately after inflateInit2() or inflateReset() and before any call of |
785 | inflate() to set the dictionary. The application must insure that the |
786 | dictionary that was used for compression is provided. |
787 | |
788 | inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a |
789 | parameter is invalid (such as NULL dictionary) or the stream state is |
790 | inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the |
791 | expected one (incorrect adler32 value). inflateSetDictionary does not |
792 | perform any decompression: this will be done by subsequent calls of |
793 | inflate(). |
794 | */ |
795 | |
796 | ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); |
797 | /* |
798 | Skips invalid compressed data until a full flush point (see above the |
799 | description of deflate with Z_FULL_FLUSH) can be found, or until all |
800 | available input is skipped. No output is provided. |
801 | |
802 | inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR |
803 | if no more input was provided, Z_DATA_ERROR if no flush point has been found, |
804 | or Z_STREAM_ERROR if the stream structure was inconsistent. In the success |
805 | case, the application may save the current current value of total_in which |
806 | indicates where valid compressed data was found. In the error case, the |
807 | application may repeatedly call inflateSync, providing more input each time, |
808 | until success or end of the input data. |
809 | */ |
810 | |
811 | ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, |
812 | z_streamp source)); |
813 | /* |
814 | Sets the destination stream as a complete copy of the source stream. |
815 | |
816 | This function can be useful when randomly accessing a large stream. The |
817 | first pass through the stream can periodically record the inflate state, |
818 | allowing restarting inflate at those points when randomly accessing the |
819 | stream. |
820 | |
821 | inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not |
822 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent |
823 | (such as zalloc being NULL). msg is left unchanged in both source and |
824 | destination. |
825 | */ |
826 | |
827 | ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); |
828 | /* |
829 | This function is equivalent to inflateEnd followed by inflateInit, |
830 | but does not free and reallocate all the internal decompression state. |
831 | The stream will keep attributes that may have been set by inflateInit2. |
832 | |
833 | inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source |
834 | stream state was inconsistent (such as zalloc or state being NULL). |
835 | */ |
836 | |
837 | ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, |
838 | int bits, |
839 | int value)); |
840 | /* |
841 | This function inserts bits in the inflate input stream. The intent is |
842 | that this function is used to start inflating at a bit position in the |
843 | middle of a byte. The provided bits will be used before any bytes are used |
844 | from next_in. This function should only be used with raw inflate, and |
845 | should be used before the first inflate() call after inflateInit2() or |
846 | inflateReset(). bits must be less than or equal to 16, and that many of the |
847 | least significant bits of value will be inserted in the input. |
848 | |
849 | inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source |
850 | stream state was inconsistent. |
851 | */ |
852 | |
853 | ZEXTERN int ZEXPORT OF((z_streamp strm, |
854 | gz_headerp head)); |
855 | /* |
856 | inflateGetHeader() requests that gzip header information be stored in the |
857 | provided gz_header structure. inflateGetHeader() may be called after |
858 | inflateInit2() or inflateReset(), and before the first call of inflate(). |
859 | As inflate() processes the gzip stream, head->done is zero until the header |
860 | is completed, at which time head->done is set to one. If a zlib stream is |
861 | being decoded, then head->done is set to -1 to indicate that there will be |
862 | no gzip header information forthcoming. Note that Z_BLOCK can be used to |
863 | force inflate() to return immediately after header processing is complete |
864 | and before any actual data is decompressed. |
865 | |
866 | The text, time, xflags, and os fields are filled in with the gzip header |
867 | contents. hcrc is set to true if there is a header CRC. (The header CRC |
868 | was valid if done is set to one.) If extra is not Z_NULL, then extra_max |
869 | contains the maximum number of bytes to write to extra. Once done is true, |
870 | extra_len contains the actual extra field length, and extra contains the |
871 | extra field, or that field truncated if extra_max is less than extra_len. |
872 | If name is not Z_NULL, then up to name_max characters are written there, |
873 | terminated with a zero unless the length is greater than name_max. If |
874 | comment is not Z_NULL, then up to comm_max characters are written there, |
875 | terminated with a zero unless the length is greater than comm_max. When |
876 | any of extra, name, or comment are not Z_NULL and the respective field is |
877 | not present in the header, then that field is set to Z_NULL to signal its |
878 | absence. This allows the use of deflateSetHeader() with the returned |
879 | structure to duplicate the header. However if those fields are set to |
880 | allocated memory, then the application will need to save those pointers |
881 | elsewhere so that they can be eventually freed. |
882 | |
883 | If inflateGetHeader is not used, then the header information is simply |
884 | discarded. The header is always checked for validity, including the header |
885 | CRC if present. inflateReset() will reset the process to discard the header |
886 | information. The application would need to call inflateGetHeader() again to |
887 | retrieve the header from the next gzip stream. |
888 | |
889 | inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source |
890 | stream state was inconsistent. |
891 | */ |
892 | |
893 | /* |
894 | ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, |
895 | unsigned char FAR *window)); |
896 | |
897 | Initialize the internal stream state for decompression using inflateBack() |
898 | calls. The fields zalloc, zfree and opaque in strm must be initialized |
899 | before the call. If zalloc and zfree are Z_NULL, then the default library- |
900 | derived memory allocation routines are used. windowBits is the base two |
901 | logarithm of the window size, in the range 8..15. window is a caller |
902 | supplied buffer of that size. Except for special applications where it is |
903 | assured that deflate was used with small window sizes, windowBits must be 15 |
904 | and a 32K byte window must be supplied to be able to decompress general |
905 | deflate streams. |
906 | |
907 | See inflateBack() for the usage of these routines. |
908 | |
909 | inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of |
910 | the paramaters are invalid, Z_MEM_ERROR if the internal state could not |
911 | be allocated, or Z_VERSION_ERROR if the version of the library does not |
912 | match the version of the header file. |
913 | */ |
914 | |
915 | typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *)); |
916 | typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); |
917 | |
918 | ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, |
919 | in_func in, void FAR *in_desc, |
920 | out_func out, void FAR *out_desc)); |
921 | /* |
922 | inflateBack() does a raw inflate with a single call using a call-back |
923 | interface for input and output. This is more efficient than inflate() for |
924 | file i/o applications in that it avoids copying between the output and the |
925 | sliding window by simply making the window itself the output buffer. This |
926 | function trusts the application to not change the output buffer passed by |
927 | the output function, at least until inflateBack() returns. |
928 | |
929 | inflateBackInit() must be called first to allocate the internal state |
930 | and to initialize the state with the user-provided window buffer. |
931 | inflateBack() may then be used multiple times to inflate a complete, raw |
932 | deflate stream with each call. inflateBackEnd() is then called to free |
933 | the allocated state. |
934 | |
935 | A raw deflate stream is one with no zlib or gzip header or trailer. |
936 | This routine would normally be used in a utility that reads zip or gzip |
937 | files and writes out uncompressed files. The utility would decode the |
938 | header and process the trailer on its own, hence this routine expects |
939 | only the raw deflate stream to decompress. This is different from the |
940 | normal behavior of inflate(), which expects either a zlib or gzip header and |
941 | trailer around the deflate stream. |
942 | |
943 | inflateBack() uses two subroutines supplied by the caller that are then |
944 | called by inflateBack() for input and output. inflateBack() calls those |
945 | routines until it reads a complete deflate stream and writes out all of the |
946 | uncompressed data, or until it encounters an error. The function's |
947 | parameters and return types are defined above in the in_func and out_func |
948 | typedefs. inflateBack() will call in(in_desc, &buf) which should return the |
949 | number of bytes of provided input, and a pointer to that input in buf. If |
950 | there is no input available, in() must return zero--buf is ignored in that |
951 | case--and inflateBack() will return a buffer error. inflateBack() will call |
952 | out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() |
953 | should return zero on success, or non-zero on failure. If out() returns |
954 | non-zero, inflateBack() will return with an error. Neither in() nor out() |
955 | are permitted to change the contents of the window provided to |
956 | inflateBackInit(), which is also the buffer that out() uses to write from. |
957 | The length written by out() will be at most the window size. Any non-zero |
958 | amount of input may be provided by in(). |
959 | |
960 | For convenience, inflateBack() can be provided input on the first call by |
961 | setting strm->next_in and strm->avail_in. If that input is exhausted, then |
962 | in() will be called. Therefore strm->next_in must be initialized before |
963 | calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called |
964 | immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in |
965 | must also be initialized, and then if strm->avail_in is not zero, input will |
966 | initially be taken from strm->next_in[0 .. strm->avail_in - 1]. |
967 | |
968 | The in_desc and out_desc parameters of inflateBack() is passed as the |
969 | first parameter of in() and out() respectively when they are called. These |
970 | descriptors can be optionally used to pass any information that the caller- |
971 | supplied in() and out() functions need to do their job. |
972 | |
973 | On return, inflateBack() will set strm->next_in and strm->avail_in to |
974 | pass back any unused input that was provided by the last in() call. The |
975 | return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR |
976 | if in() or out() returned an error, Z_DATA_ERROR if there was a format |
977 | error in the deflate stream (in which case strm->msg is set to indicate the |
978 | nature of the error), or Z_STREAM_ERROR if the stream was not properly |
979 | initialized. In the case of Z_BUF_ERROR, an input or output error can be |
980 | distinguished using strm->next_in which will be Z_NULL only if in() returned |
981 | an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to |
982 | out() returning non-zero. (in() will always be called before out(), so |
983 | strm->next_in is assured to be defined if out() returns non-zero.) Note |
984 | that inflateBack() cannot return Z_OK. |
985 | */ |
986 | |
987 | ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); |
988 | /* |
989 | All memory allocated by inflateBackInit() is freed. |
990 | |
991 | inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream |
992 | state was inconsistent. |
993 | */ |
994 | |
995 | ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); |
996 | /* Return flags indicating compile-time options. |
997 | |
998 | Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: |
999 | 1.0: size of uInt |
1000 | 3.2: size of uLong |
1001 | 5.4: size of voidpf (pointer) |
1002 | 7.6: size of z_off_t |
1003 | |
1004 | Compiler, assembler, and debug options: |
1005 | 8: DEBUG |
1006 | 9: ASMV or ASMINF -- use ASM code |
1007 | 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention |
1008 | 11: 0 (reserved) |
1009 | |
1010 | One-time table building (smaller code, but not thread-safe if true): |
1011 | 12: BUILDFIXED -- build static block decoding tables when needed |
1012 | 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed |
1013 | 14,15: 0 (reserved) |
1014 | |
1015 | Library content (indicates missing functionality): |
1016 | 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking |
1017 | deflate code when not needed) |
1018 | 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect |
1019 | and decode gzip streams (to avoid linking crc code) |
1020 | 18-19: 0 (reserved) |
1021 | |
1022 | Operation variations (changes in library functionality): |
1023 | 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate |
1024 | 21: FASTEST -- deflate algorithm with only one, lowest compression level |
1025 | 22,23: 0 (reserved) |
1026 | |
1027 | The sprintf variant used by gzprintf (zero is best): |
1028 | 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format |
1029 | 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! |
1030 | 26: 0 = returns value, 1 = void -- 1 means inferred string length returned |
1031 | |
1032 | Remainder: |
1033 | 27-31: 0 (reserved) |
1034 | */ |
1035 | |
1036 | |
1037 | /* utility functions */ |
1038 | |
1039 | /* |
1040 | The following utility functions are implemented on top of the |
1041 | basic stream-oriented functions. To simplify the interface, some |
1042 | default options are assumed (compression level and memory usage, |
1043 | standard memory allocation functions). The source code of these |
1044 | utility functions can easily be modified if you need special options. |
1045 | */ |
1046 | |
1047 | ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, |
1048 | const Bytef *source, uLong sourceLen)); |
1049 | /* |
1050 | Compresses the source buffer into the destination buffer. sourceLen is |
1051 | the byte length of the source buffer. Upon entry, destLen is the total |
1052 | size of the destination buffer, which must be at least the value returned |
1053 | by compressBound(sourceLen). Upon exit, destLen is the actual size of the |
1054 | compressed buffer. |
1055 | This function can be used to compress a whole file at once if the |
1056 | input file is mmap'ed. |
1057 | compress returns Z_OK if success, Z_MEM_ERROR if there was not |
1058 | enough memory, Z_BUF_ERROR if there was not enough room in the output |
1059 | buffer. |
1060 | */ |
1061 | |
1062 | ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, |
1063 | const Bytef *source, uLong sourceLen, |
1064 | int level)); |
1065 | /* |
1066 | Compresses the source buffer into the destination buffer. The level |
1067 | parameter has the same meaning as in deflateInit. sourceLen is the byte |
1068 | length of the source buffer. Upon entry, destLen is the total size of the |
1069 | destination buffer, which must be at least the value returned by |
1070 | compressBound(sourceLen). Upon exit, destLen is the actual size of the |
1071 | compressed buffer. |
1072 | |
1073 | compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
1074 | memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
1075 | Z_STREAM_ERROR if the level parameter is invalid. |
1076 | */ |
1077 | |
1078 | ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); |
1079 | /* |
1080 | compressBound() returns an upper bound on the compressed size after |
1081 | compress() or compress2() on sourceLen bytes. It would be used before |
1082 | a compress() or compress2() call to allocate the destination buffer. |
1083 | */ |
1084 | |
1085 | ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, |
1086 | const Bytef *source, uLong sourceLen)); |
1087 | /* |
1088 | Decompresses the source buffer into the destination buffer. sourceLen is |
1089 | the byte length of the source buffer. Upon entry, destLen is the total |
1090 | size of the destination buffer, which must be large enough to hold the |
1091 | entire uncompressed data. (The size of the uncompressed data must have |
1092 | been saved previously by the compressor and transmitted to the decompressor |
1093 | by some mechanism outside the scope of this compression library.) |
1094 | Upon exit, destLen is the actual size of the compressed buffer. |
1095 | This function can be used to decompress a whole file at once if the |
1096 | input file is mmap'ed. |
1097 | |
1098 | uncompress returns Z_OK if success, Z_MEM_ERROR if there was not |
1099 | enough memory, Z_BUF_ERROR if there was not enough room in the output |
1100 | buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. |
1101 | */ |
1102 | |
1103 | #if XNU_KERNEL_PRIVATE |
1104 | |
1105 | ZEXTERN uLong zlib_deflate_memory_size(int wbits, int memlevel); |
1106 | |
1107 | #endif /* XNU_KERNEL_PRIVATE */ |
1108 | |
1109 | #if !KERNEL |
1110 | |
1111 | typedef voidp gzFile; |
1112 | |
1113 | ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); |
1114 | /* |
1115 | Opens a gzip (.gz) file for reading or writing. The mode parameter |
1116 | is as in fopen ("rb" or "wb") but can also include a compression level |
1117 | ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for |
1118 | Huffman only compression as in "wb1h", or 'R' for run-length encoding |
1119 | as in "wb1R". (See the description of deflateInit2 for more information |
1120 | about the strategy parameter.) |
1121 | |
1122 | gzopen can be used to read a file which is not in gzip format; in this |
1123 | case gzread will directly read from the file without decompression. |
1124 | |
1125 | gzopen returns NULL if the file could not be opened or if there was |
1126 | insufficient memory to allocate the (de)compression state; errno |
1127 | can be checked to distinguish the two cases (if errno is zero, the |
1128 | zlib error is Z_MEM_ERROR). */ |
1129 | |
1130 | ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); |
1131 | /* |
1132 | gzdopen() associates a gzFile with the file descriptor fd. File |
1133 | descriptors are obtained from calls like open, dup, creat, pipe or |
1134 | fileno (in the file has been previously opened with fopen). |
1135 | The mode parameter is as in gzopen. |
1136 | The next call of gzclose on the returned gzFile will also close the |
1137 | file descriptor fd, just like fclose(fdopen(fd), mode) closes the file |
1138 | descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode). |
1139 | gzdopen returns NULL if there was insufficient memory to allocate |
1140 | the (de)compression state. |
1141 | */ |
1142 | |
1143 | ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); |
1144 | /* |
1145 | Dynamically update the compression level or strategy. See the description |
1146 | of deflateInit2 for the meaning of these parameters. |
1147 | gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not |
1148 | opened for writing. |
1149 | */ |
1150 | |
1151 | ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); |
1152 | /* |
1153 | Reads the given number of uncompressed bytes from the compressed file. |
1154 | If the input file was not in gzip format, gzread copies the given number |
1155 | of bytes into the buffer. |
1156 | gzread returns the number of uncompressed bytes actually read (0 for |
1157 | end of file, -1 for error). */ |
1158 | |
1159 | ZEXTERN int ZEXPORT gzwrite OF((gzFile file, |
1160 | voidpc buf, unsigned len)); |
1161 | /* |
1162 | Writes the given number of uncompressed bytes into the compressed file. |
1163 | gzwrite returns the number of uncompressed bytes actually written |
1164 | (0 in case of error). |
1165 | */ |
1166 | |
1167 | ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); |
1168 | /* |
1169 | Converts, formats, and writes the args to the compressed file under |
1170 | control of the format string, as in fprintf. gzprintf returns the number of |
1171 | uncompressed bytes actually written (0 in case of error). The number of |
1172 | uncompressed bytes written is limited to 4095. The caller should assure that |
1173 | this limit is not exceeded. If it is exceeded, then gzprintf() will return |
1174 | return an error (0) with nothing written. In this case, there may also be a |
1175 | buffer overflow with unpredictable consequences, which is possible only if |
1176 | zlib was compiled with the insecure functions sprintf() or vsprintf() |
1177 | because the secure snprintf() or vsnprintf() functions were not available. |
1178 | */ |
1179 | |
1180 | ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); |
1181 | /* |
1182 | Writes the given null-terminated string to the compressed file, excluding |
1183 | the terminating null character. |
1184 | gzputs returns the number of characters written, or -1 in case of error. |
1185 | */ |
1186 | |
1187 | ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); |
1188 | /* |
1189 | Reads bytes from the compressed file until len-1 characters are read, or |
1190 | a newline character is read and transferred to buf, or an end-of-file |
1191 | condition is encountered. The string is then terminated with a null |
1192 | character. |
1193 | gzgets returns buf, or Z_NULL in case of error. |
1194 | */ |
1195 | |
1196 | ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); |
1197 | /* |
1198 | Writes c, converted to an unsigned char, into the compressed file. |
1199 | gzputc returns the value that was written, or -1 in case of error. |
1200 | */ |
1201 | |
1202 | ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); |
1203 | /* |
1204 | Reads one byte from the compressed file. gzgetc returns this byte |
1205 | or -1 in case of end of file or error. |
1206 | */ |
1207 | |
1208 | ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); |
1209 | /* |
1210 | Push one character back onto the stream to be read again later. |
1211 | Only one character of push-back is allowed. gzungetc() returns the |
1212 | character pushed, or -1 on failure. gzungetc() will fail if a |
1213 | character has been pushed but not read yet, or if c is -1. The pushed |
1214 | character will be discarded if the stream is repositioned with gzseek() |
1215 | or gzrewind(). |
1216 | */ |
1217 | |
1218 | ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); |
1219 | /* |
1220 | Flushes all pending output into the compressed file. The parameter |
1221 | flush is as in the deflate() function. The return value is the zlib |
1222 | error number (see function gzerror below). gzflush returns Z_OK if |
1223 | the flush parameter is Z_FINISH and all output could be flushed. |
1224 | gzflush should be called only when strictly necessary because it can |
1225 | degrade compression. |
1226 | */ |
1227 | |
1228 | ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, |
1229 | z_off_t offset, int whence)); |
1230 | /* |
1231 | Sets the starting position for the next gzread or gzwrite on the |
1232 | given compressed file. The offset represents a number of bytes in the |
1233 | uncompressed data stream. The whence parameter is defined as in lseek(2); |
1234 | the value SEEK_END is not supported. |
1235 | If the file is opened for reading, this function is emulated but can be |
1236 | extremely slow. If the file is opened for writing, only forward seeks are |
1237 | supported; gzseek then compresses a sequence of zeroes up to the new |
1238 | starting position. |
1239 | |
1240 | gzseek returns the resulting offset location as measured in bytes from |
1241 | the beginning of the uncompressed stream, or -1 in case of error, in |
1242 | particular if the file is opened for writing and the new starting position |
1243 | would be before the current position. |
1244 | */ |
1245 | |
1246 | ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); |
1247 | /* |
1248 | Rewinds the given file. This function is supported only for reading. |
1249 | |
1250 | gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) |
1251 | */ |
1252 | |
1253 | ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); |
1254 | /* |
1255 | Returns the starting position for the next gzread or gzwrite on the |
1256 | given compressed file. This position represents a number of bytes in the |
1257 | uncompressed data stream. |
1258 | |
1259 | gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) |
1260 | */ |
1261 | |
1262 | ZEXTERN int ZEXPORT gzeof OF((gzFile file)); |
1263 | /* |
1264 | Returns 1 when EOF has previously been detected reading the given |
1265 | input stream, otherwise zero. |
1266 | */ |
1267 | |
1268 | ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); |
1269 | /* |
1270 | Returns 1 if file is being read directly without decompression, otherwise |
1271 | zero. |
1272 | */ |
1273 | |
1274 | ZEXTERN int ZEXPORT gzclose OF((gzFile file)); |
1275 | /* |
1276 | Flushes all pending output if necessary, closes the compressed file |
1277 | and deallocates all the (de)compression state. The return value is the zlib |
1278 | error number (see function gzerror below). |
1279 | */ |
1280 | |
1281 | ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); |
1282 | /* |
1283 | Returns the error message for the last error which occurred on the |
1284 | given compressed file. errnum is set to zlib error number. If an |
1285 | error occurred in the file system and not in the compression library, |
1286 | errnum is set to Z_ERRNO and the application may consult errno |
1287 | to get the exact error code. |
1288 | */ |
1289 | |
1290 | ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); |
1291 | /* |
1292 | Clears the error and end-of-file flags for file. This is analogous to the |
1293 | clearerr() function in stdio. This is useful for continuing to read a gzip |
1294 | file that is being written concurrently. |
1295 | */ |
1296 | |
1297 | #endif /* KERNEL */ |
1298 | |
1299 | /* checksum functions */ |
1300 | |
1301 | /* |
1302 | These functions are not related to compression but are exported |
1303 | anyway because they might be useful in applications using the |
1304 | compression library. |
1305 | */ |
1306 | |
1307 | ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); |
1308 | /* |
1309 | Update a running Adler-32 checksum with the bytes buf[0..len-1] and |
1310 | return the updated checksum. If buf is NULL, this function returns |
1311 | the required initial value for the checksum. |
1312 | An Adler-32 checksum is almost as reliable as a CRC32 but can be computed |
1313 | much faster. Usage example: |
1314 | |
1315 | uLong adler = adler32(0L, Z_NULL, 0); |
1316 | |
1317 | while (read_buffer(buffer, length) != EOF) { |
1318 | adler = adler32(adler, buffer, length); |
1319 | } |
1320 | if (adler != original_adler) error(); |
1321 | */ |
1322 | |
1323 | ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, |
1324 | z_off_t len2)); |
1325 | /* |
1326 | Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 |
1327 | and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for |
1328 | each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of |
1329 | seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. |
1330 | */ |
1331 | |
1332 | ZEXTERN uLong ZEXPORT z_crc32 OF((uLong crc, const Bytef *buf, uInt len)); |
1333 | /* |
1334 | Update a running CRC-32 with the bytes buf[0..len-1] and return the |
1335 | updated CRC-32. If buf is NULL, this function returns the required initial |
1336 | value for the for the crc. Pre- and post-conditioning (one's complement) is |
1337 | performed within this function so it shouldn't be done by the application. |
1338 | Usage example: |
1339 | |
1340 | uLong crc = crc32(0L, Z_NULL, 0); |
1341 | |
1342 | while (read_buffer(buffer, length) != EOF) { |
1343 | crc = crc32(crc, buffer, length); |
1344 | } |
1345 | if (crc != original_crc) error(); |
1346 | */ |
1347 | |
1348 | ZEXTERN uLong ZEXPORT z_crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); |
1349 | |
1350 | /* |
1351 | Combine two CRC-32 check values into one. For two sequences of bytes, |
1352 | seq1 and seq2 with lengths len1 and len2, CRC-32 check values were |
1353 | calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 |
1354 | check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and |
1355 | len2. |
1356 | */ |
1357 | |
1358 | |
1359 | /* various hacks, don't look :) */ |
1360 | |
1361 | /* deflateInit and inflateInit are macros to allow checking the zlib version |
1362 | * and the compiler's view of z_stream: |
1363 | */ |
1364 | ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, |
1365 | const char *version, int stream_size)); |
1366 | ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, |
1367 | const char *version, int stream_size)); |
1368 | ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, |
1369 | int windowBits, int memLevel, |
1370 | int strategy, const char *version, |
1371 | int stream_size)); |
1372 | ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, |
1373 | const char *version, int stream_size)); |
1374 | ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, |
1375 | unsigned char FAR *window, |
1376 | const char *version, |
1377 | int stream_size)); |
1378 | #define deflateInit(strm, level) \ |
1379 | deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) |
1380 | #define inflateInit(strm) \ |
1381 | inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) |
1382 | #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ |
1383 | deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ |
1384 | (strategy), ZLIB_VERSION, sizeof(z_stream)) |
1385 | #define inflateInit2(strm, windowBits) \ |
1386 | inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) |
1387 | #define inflateBackInit(strm, windowBits, window) \ |
1388 | inflateBackInit_((strm), (windowBits), (window), \ |
1389 | ZLIB_VERSION, sizeof(z_stream)) |
1390 | |
1391 | |
1392 | #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) |
1393 | struct internal_state {int dummy;}; /* hack for buggy compilers */ |
1394 | #endif |
1395 | |
1396 | ZEXTERN const char * ZEXPORT zError OF((int)); |
1397 | ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z)); |
1398 | ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void)); |
1399 | |
1400 | #ifdef __cplusplus |
1401 | } |
1402 | #endif |
1403 | |
1404 | #endif /* ZLIB_H */ |
1405 | |