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861c20b4 PM |
1 | /* $Id$ */ |
2 | ||
3 | /* | |
4 | * This file is derived from zlib.h and zconf.h from the zlib-0.95 | |
5 | * distribution by Jean-loup Gailly and Mark Adler, with some additions | |
6 | * by Paul Mackerras to aid in implementing Deflate compression and | |
7 | * decompression for PPP packets. | |
8 | */ | |
9 | ||
10 | /* zlib.h -- interface of the 'zlib' general purpose compression library | |
11 | version 0.95, Aug 16th, 1995. | |
12 | ||
13 | Copyright (C) 1995 Jean-loup Gailly and Mark Adler | |
14 | ||
15 | This software is provided 'as-is', without any express or implied | |
16 | warranty. In no event will the authors be held liable for any damages | |
17 | arising from the use of this software. | |
18 | ||
19 | Permission is granted to anyone to use this software for any purpose, | |
20 | including commercial applications, and to alter it and redistribute it | |
21 | freely, subject to the following restrictions: | |
22 | ||
23 | 1. The origin of this software must not be misrepresented; you must not | |
24 | claim that you wrote the original software. If you use this software | |
25 | in a product, an acknowledgment in the product documentation would be | |
26 | appreciated but is not required. | |
27 | 2. Altered source versions must be plainly marked as such, and must not be | |
28 | misrepresented as being the original software. | |
29 | 3. This notice may not be removed or altered from any source distribution. | |
30 | ||
31 | Jean-loup Gailly Mark Adler | |
32 | gzip@prep.ai.mit.edu madler@alumni.caltech.edu | |
33 | */ | |
34 | ||
35 | #ifndef _ZLIB_H | |
36 | #define _ZLIB_H | |
37 | ||
38 | /* #include "zconf.h" */ /* included directly here */ | |
39 | ||
40 | /* zconf.h -- configuration of the zlib compression library | |
41 | * Copyright (C) 1995 Jean-loup Gailly. | |
42 | * For conditions of distribution and use, see copyright notice in zlib.h | |
43 | */ | |
44 | ||
45 | /* From: zconf.h,v 1.12 1995/05/03 17:27:12 jloup Exp */ | |
46 | ||
47 | /* | |
48 | The library does not install any signal handler. It is recommended to | |
49 | add at least a handler for SIGSEGV when decompressing; the library checks | |
50 | the consistency of the input data whenever possible but may go nuts | |
51 | for some forms of corrupted input. | |
52 | */ | |
53 | ||
54 | /* | |
55 | * Compile with -DMAXSEG_64K if the alloc function cannot allocate more | |
56 | * than 64k bytes at a time (needed on systems with 16-bit int). | |
57 | * Compile with -DUNALIGNED_OK if it is OK to access shorts or ints | |
58 | * at addresses which are not a multiple of their size. | |
59 | * Under DOS, -DFAR=far or -DFAR=__far may be needed. | |
60 | */ | |
61 | ||
62 | #ifndef STDC | |
63 | # if defined(MSDOS) || defined(__STDC__) || defined(__cplusplus) | |
64 | # define STDC | |
65 | # endif | |
66 | #endif | |
67 | ||
68 | #ifdef __MWERKS__ /* Metrowerks CodeWarrior declares fileno() in unix.h */ | |
69 | # include <unix.h> | |
70 | #endif | |
71 | ||
72 | /* Maximum value for memLevel in deflateInit2 */ | |
73 | #ifndef MAX_MEM_LEVEL | |
74 | # ifdef MAXSEG_64K | |
75 | # define MAX_MEM_LEVEL 8 | |
76 | # else | |
77 | # define MAX_MEM_LEVEL 9 | |
78 | # endif | |
79 | #endif | |
80 | ||
81 | #ifndef FAR | |
82 | # define FAR | |
83 | #endif | |
84 | ||
85 | /* Maximum value for windowBits in deflateInit2 and inflateInit2 */ | |
86 | #ifndef MAX_WBITS | |
87 | # define MAX_WBITS 15 /* 32K LZ77 window */ | |
88 | #endif | |
89 | ||
90 | /* The memory requirements for deflate are (in bytes): | |
91 | 1 << (windowBits+2) + 1 << (memLevel+9) | |
92 | that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values) | |
93 | plus a few kilobytes for small objects. For example, if you want to reduce | |
94 | the default memory requirements from 256K to 128K, compile with | |
95 | make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7" | |
96 | Of course this will generally degrade compression (there's no free lunch). | |
97 | ||
98 | The memory requirements for inflate are (in bytes) 1 << windowBits | |
99 | that is, 32K for windowBits=15 (default value) plus a few kilobytes | |
100 | for small objects. | |
101 | */ | |
102 | ||
103 | /* Type declarations */ | |
104 | ||
105 | #ifndef OF /* function prototypes */ | |
106 | # ifdef STDC | |
107 | # define OF(args) args | |
108 | # else | |
109 | # define OF(args) () | |
110 | # endif | |
111 | #endif | |
112 | ||
113 | typedef unsigned char Byte; /* 8 bits */ | |
114 | typedef unsigned int uInt; /* 16 bits or more */ | |
5c36219d AT |
115 | typedef int32 Long; /* 32 bits or more */ |
116 | typedef uint32 uLong; /* 32 bits or more */ | |
861c20b4 PM |
117 | |
118 | typedef Byte FAR Bytef; | |
119 | typedef char FAR charf; | |
120 | typedef int FAR intf; | |
121 | typedef uInt FAR uIntf; | |
122 | typedef uLong FAR uLongf; | |
123 | ||
124 | #ifdef STDC | |
125 | typedef void FAR *voidpf; | |
126 | typedef void *voidp; | |
127 | #else | |
128 | typedef Byte FAR *voidpf; | |
129 | typedef Byte *voidp; | |
130 | #endif | |
131 | ||
132 | /* end of original zconf.h */ | |
133 | ||
134 | #define ZLIB_VERSION "0.95P" | |
135 | ||
136 | /* | |
137 | The 'zlib' compression library provides in-memory compression and | |
138 | decompression functions, including integrity checks of the uncompressed | |
139 | data. This version of the library supports only one compression method | |
140 | (deflation) but other algorithms may be added later and will have the same | |
141 | stream interface. | |
142 | ||
143 | For compression the application must provide the output buffer and | |
144 | may optionally provide the input buffer for optimization. For decompression, | |
145 | the application must provide the input buffer and may optionally provide | |
146 | the output buffer for optimization. | |
147 | ||
148 | Compression can be done in a single step if the buffers are large | |
149 | enough (for example if an input file is mmap'ed), or can be done by | |
150 | repeated calls of the compression function. In the latter case, the | |
151 | application must provide more input and/or consume the output | |
152 | (providing more output space) before each call. | |
153 | */ | |
154 | ||
155 | typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); | |
156 | typedef void (*free_func) OF((voidpf opaque, voidpf address, uInt nbytes)); | |
157 | ||
158 | struct internal_state; | |
159 | ||
160 | typedef struct z_stream_s { | |
161 | Bytef *next_in; /* next input byte */ | |
162 | uInt avail_in; /* number of bytes available at next_in */ | |
163 | uLong total_in; /* total nb of input bytes read so far */ | |
164 | ||
165 | Bytef *next_out; /* next output byte should be put there */ | |
166 | uInt avail_out; /* remaining free space at next_out */ | |
167 | uLong total_out; /* total nb of bytes output so far */ | |
168 | ||
169 | char *msg; /* last error message, NULL if no error */ | |
170 | struct internal_state FAR *state; /* not visible by applications */ | |
171 | ||
172 | alloc_func zalloc; /* used to allocate the internal state */ | |
173 | free_func zfree; /* used to free the internal state */ | |
174 | voidp opaque; /* private data object passed to zalloc and zfree */ | |
175 | ||
176 | Byte data_type; /* best guess about the data type: ascii or binary */ | |
177 | ||
178 | } z_stream; | |
179 | ||
180 | /* | |
181 | The application must update next_in and avail_in when avail_in has | |
182 | dropped to zero. It must update next_out and avail_out when avail_out | |
183 | has dropped to zero. The application must initialize zalloc, zfree and | |
184 | opaque before calling the init function. All other fields are set by the | |
185 | compression library and must not be updated by the application. | |
186 | ||
187 | The opaque value provided by the application will be passed as the first | |
188 | parameter for calls of zalloc and zfree. This can be useful for custom | |
189 | memory management. The compression library attaches no meaning to the | |
190 | opaque value. | |
191 | ||
192 | zalloc must return Z_NULL if there is not enough memory for the object. | |
193 | On 16-bit systems, the functions zalloc and zfree must be able to allocate | |
194 | exactly 65536 bytes, but will not be required to allocate more than this | |
195 | if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, | |
196 | pointers returned by zalloc for objects of exactly 65536 bytes *must* | |
197 | have their offset normalized to zero. The default allocation function | |
198 | provided by this library ensures this (see zutil.c). To reduce memory | |
199 | requirements and avoid any allocation of 64K objects, at the expense of | |
200 | compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). | |
201 | ||
202 | The fields total_in and total_out can be used for statistics or | |
203 | progress reports. After compression, total_in holds the total size of | |
204 | the uncompressed data and may be saved for use in the decompressor | |
205 | (particularly if the decompressor wants to decompress everything in | |
206 | a single step). | |
207 | */ | |
208 | ||
209 | /* constants */ | |
210 | ||
211 | #define Z_NO_FLUSH 0 | |
212 | #define Z_PARTIAL_FLUSH 1 | |
213 | #define Z_FULL_FLUSH 2 | |
214 | #define Z_SYNC_FLUSH 3 /* experimental: partial_flush + byte align */ | |
215 | #define Z_FINISH 4 | |
216 | #define Z_PACKET_FLUSH 5 | |
217 | #define Z_INSERT_ONLY 6 /* update hash table etc., produce no output */ | |
218 | /* See deflate() below for the usage of these constants */ | |
219 | ||
220 | #define Z_OK 0 | |
221 | #define Z_STREAM_END 1 | |
222 | #define Z_ERRNO (-1) | |
223 | #define Z_STREAM_ERROR (-2) | |
224 | #define Z_DATA_ERROR (-3) | |
225 | #define Z_MEM_ERROR (-4) | |
226 | #define Z_BUF_ERROR (-5) | |
227 | /* error codes for the compression/decompression functions */ | |
228 | ||
229 | #define Z_BEST_SPEED 1 | |
230 | #define Z_BEST_COMPRESSION 9 | |
231 | #define Z_DEFAULT_COMPRESSION (-1) | |
232 | /* compression levels */ | |
233 | ||
234 | #define Z_FILTERED 1 | |
235 | #define Z_HUFFMAN_ONLY 2 | |
236 | #define Z_DEFAULT_STRATEGY 0 | |
237 | ||
238 | #define Z_BINARY 0 | |
239 | #define Z_ASCII 1 | |
240 | #define Z_UNKNOWN 2 | |
241 | /* Used to set the data_type field */ | |
242 | ||
243 | #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ | |
244 | ||
245 | extern char *zlib_version; | |
246 | /* The application can compare zlib_version and ZLIB_VERSION for consistency. | |
247 | If the first character differs, the library code actually used is | |
248 | not compatible with the zlib.h header file used by the application. | |
249 | */ | |
250 | ||
251 | /* basic functions */ | |
252 | ||
253 | extern int deflateInit OF((z_stream *strm, int level)); | |
254 | /* | |
255 | Initializes the internal stream state for compression. The fields | |
256 | zalloc, zfree and opaque must be initialized before by the caller. | |
257 | If zalloc and zfree are set to Z_NULL, deflateInit updates them to | |
258 | use default allocation functions. | |
259 | ||
260 | The compression level must be Z_DEFAULT_COMPRESSION, or between 1 and 9: | |
261 | 1 gives best speed, 9 gives best compression. Z_DEFAULT_COMPRESSION requests | |
262 | a default compromise between speed and compression (currently equivalent | |
263 | to level 6). | |
264 | ||
265 | deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not | |
266 | enough memory, Z_STREAM_ERROR if level is not a valid compression level. | |
267 | msg is set to null if there is no error message. deflateInit does not | |
268 | perform any compression: this will be done by deflate(). | |
269 | */ | |
270 | ||
271 | ||
272 | extern int deflate OF((z_stream *strm, int flush)); | |
273 | /* | |
274 | Performs one or both of the following actions: | |
275 | ||
276 | - Compress more input starting at next_in and update next_in and avail_in | |
277 | accordingly. If not all input can be processed (because there is not | |
278 | enough room in the output buffer), next_in and avail_in are updated and | |
279 | processing will resume at this point for the next call of deflate(). | |
280 | ||
281 | - Provide more output starting at next_out and update next_out and avail_out | |
282 | accordingly. This action is forced if the parameter flush is non zero. | |
283 | Forcing flush frequently degrades the compression ratio, so this parameter | |
284 | should be set only when necessary (in interactive applications). | |
285 | Some output may be provided even if flush is not set. | |
286 | ||
287 | Before the call of deflate(), the application should ensure that at least | |
288 | one of the actions is possible, by providing more input and/or consuming | |
289 | more output, and updating avail_in or avail_out accordingly; avail_out | |
290 | should never be zero before the call. The application can consume the | |
291 | compressed output when it wants, for example when the output buffer is full | |
292 | (avail_out == 0), or after each call of deflate(). | |
293 | ||
294 | If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression | |
295 | block is terminated and flushed to the output buffer so that the | |
296 | decompressor can get all input data available so far. For method 9, a future | |
297 | variant on method 8, the current block will be flushed but not terminated. | |
298 | If flush is set to Z_FULL_FLUSH, the compression block is terminated, a | |
299 | special marker is output and the compression dictionary is discarded; this | |
300 | is useful to allow the decompressor to synchronize if one compressed block | |
301 | has been damaged (see inflateSync below). Flushing degrades compression and | |
302 | so should be used only when necessary. Using Z_FULL_FLUSH too often can | |
303 | seriously degrade the compression. If deflate returns with avail_out == 0, | |
304 | this function must be called again with the same value of the flush | |
305 | parameter and more output space (updated avail_out), until the flush is | |
306 | complete (deflate returns with non-zero avail_out). | |
307 | ||
308 | If the parameter flush is set to Z_PACKET_FLUSH, the compression | |
309 | block is terminated, and a zero-length stored block is output, | |
310 | omitting the length bytes (the effect of this is that the 3-bit type | |
311 | code 000 for a stored block is output, and the output is then | |
312 | byte-aligned). This is designed for use at the end of a PPP packet. | |
313 | In addition, if the current compression block contains all the data | |
314 | since the last Z_PACKET_FLUSH, it is never output as a stored block. | |
315 | If the current compression block output as a static or dynamic block | |
316 | would not be at least `minCompression' bytes smaller than the | |
317 | original data, then nothing is output for that block. (The type | |
318 | code for the zero-length stored block is still output, resulting in | |
319 | a single zero byte being output for the whole packet.) | |
320 | `MinCompression' is a parameter to deflateInit2, or 0 if deflateInit | |
321 | is used. | |
322 | ||
323 | If the parameter flush is set to Z_FINISH, all pending input is processed, | |
324 | all pending output is flushed and deflate returns with Z_STREAM_END if there | |
325 | was enough output space; if deflate returns with Z_OK, this function must be | |
326 | called again with Z_FINISH and more output space (updated avail_out) but no | |
327 | more input data, until it returns with Z_STREAM_END or an error. After | |
328 | deflate has returned Z_STREAM_END, the only possible operations on the | |
329 | stream are deflateReset or deflateEnd. | |
330 | ||
331 | Z_FINISH can be used immediately after deflateInit if all the compression | |
332 | is to be done in a single step. In this case, avail_out must be at least | |
333 | 0.1% larger than avail_in plus 12 bytes. If deflate does not return | |
334 | Z_STREAM_END, then it must be called again as described above. | |
335 | ||
336 | deflate() may update data_type if it can make a good guess about | |
337 | the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered | |
338 | binary. This field is only for information purposes and does not affect | |
339 | the compression algorithm in any manner. | |
340 | ||
341 | deflate() returns Z_OK if some progress has been made (more input | |
342 | processed or more output produced), Z_STREAM_END if all input has been | |
343 | consumed and all output has been produced (only when flush is set to | |
344 | Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example | |
345 | if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible. | |
346 | */ | |
347 | ||
348 | ||
349 | extern int deflateEnd OF((z_stream *strm)); | |
350 | /* | |
351 | All dynamically allocated data structures for this stream are freed. | |
352 | This function discards any unprocessed input and does not flush any | |
353 | pending output. | |
354 | ||
355 | deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the | |
356 | stream state was inconsistent. In the error case, msg may be set | |
357 | but then points to a static string (which must not be deallocated). | |
358 | */ | |
359 | ||
360 | ||
361 | extern int inflateInit OF((z_stream *strm)); | |
362 | /* | |
363 | Initializes the internal stream state for decompression. The fields | |
364 | zalloc and zfree must be initialized before by the caller. If zalloc and | |
365 | zfree are set to Z_NULL, inflateInit updates them to use default allocation | |
366 | functions. | |
367 | ||
368 | inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not | |
369 | enough memory. msg is set to null if there is no error message. | |
370 | inflateInit does not perform any decompression: this will be done by | |
371 | inflate(). | |
372 | */ | |
373 | ||
374 | ||
375 | extern int inflate OF((z_stream *strm, int flush)); | |
376 | /* | |
377 | Performs one or both of the following actions: | |
378 | ||
379 | - Decompress more input starting at next_in and update next_in and avail_in | |
380 | accordingly. If not all input can be processed (because there is not | |
381 | enough room in the output buffer), next_in is updated and processing | |
382 | will resume at this point for the next call of inflate(). | |
383 | ||
384 | - Provide more output starting at next_out and update next_out and avail_out | |
385 | accordingly. inflate() always provides as much output as possible | |
386 | (until there is no more input data or no more space in the output buffer). | |
387 | ||
388 | Before the call of inflate(), the application should ensure that at least | |
389 | one of the actions is possible, by providing more input and/or consuming | |
390 | more output, and updating the next_* and avail_* values accordingly. | |
391 | The application can consume the uncompressed output when it wants, for | |
392 | example when the output buffer is full (avail_out == 0), or after each | |
393 | call of inflate(). | |
394 | ||
395 | If the parameter flush is set to Z_PARTIAL_FLUSH or Z_PACKET_FLUSH, | |
396 | inflate flushes as much output as possible to the output buffer. The | |
397 | flushing behavior of inflate is not specified for values of the flush | |
398 | parameter other than Z_PARTIAL_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the | |
399 | current implementation actually flushes as much output as possible | |
400 | anyway. For Z_PACKET_FLUSH, inflate checks that once all the input data | |
401 | has been consumed, it is expecting to see the length field of a stored | |
402 | block; if not, it returns Z_DATA_ERROR. | |
403 | ||
404 | inflate() should normally be called until it returns Z_STREAM_END or an | |
405 | error. However if all decompression is to be performed in a single step | |
406 | (a single call of inflate), the parameter flush should be set to | |
407 | Z_FINISH. In this case all pending input is processed and all pending | |
408 | output is flushed; avail_out must be large enough to hold all the | |
409 | uncompressed data. (The size of the uncompressed data may have been saved | |
410 | by the compressor for this purpose.) The next operation on this stream must | |
411 | be inflateEnd to deallocate the decompression state. The use of Z_FINISH | |
412 | is never required, but can be used to inform inflate that a faster routine | |
413 | may be used for the single inflate() call. | |
414 | ||
415 | inflate() returns Z_OK if some progress has been made (more input | |
416 | processed or more output produced), Z_STREAM_END if the end of the | |
417 | compressed data has been reached and all uncompressed output has been | |
418 | produced, Z_DATA_ERROR if the input data was corrupted, Z_STREAM_ERROR if | |
419 | the stream structure was inconsistent (for example if next_in or next_out | |
420 | was NULL), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if no | |
421 | progress is possible or if there was not enough room in the output buffer | |
422 | when Z_FINISH is used. In the Z_DATA_ERROR case, the application may then | |
423 | call inflateSync to look for a good compression block. */ | |
424 | ||
425 | ||
426 | extern int inflateEnd OF((z_stream *strm)); | |
427 | /* | |
428 | All dynamically allocated data structures for this stream are freed. | |
429 | This function discards any unprocessed input and does not flush any | |
430 | pending output. | |
431 | ||
432 | inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state | |
433 | was inconsistent. In the error case, msg may be set but then points to a | |
434 | static string (which must not be deallocated). | |
435 | */ | |
436 | ||
437 | /* advanced functions */ | |
438 | ||
439 | /* | |
440 | The following functions are needed only in some special applications. | |
441 | */ | |
442 | ||
443 | extern int deflateInit2 OF((z_stream *strm, | |
444 | int level, | |
445 | int method, | |
446 | int windowBits, | |
447 | int memLevel, | |
f8062104 | 448 | int strategy)); |
861c20b4 PM |
449 | /* |
450 | This is another version of deflateInit with more compression options. The | |
451 | fields next_in, zalloc and zfree must be initialized before by the caller. | |
452 | ||
453 | The method parameter is the compression method. It must be 8 in this | |
454 | version of the library. (Method 9 will allow a 64K history buffer and | |
455 | partial block flushes.) | |
456 | ||
457 | The windowBits parameter is the base two logarithm of the window size | |
458 | (the size of the history buffer). It should be in the range 8..15 for this | |
459 | version of the library (the value 16 will be allowed for method 9). Larger | |
460 | values of this parameter result in better compression at the expense of | |
461 | memory usage. The default value is 15 if deflateInit is used instead. | |
462 | ||
463 | The memLevel parameter specifies how much memory should be allocated | |
464 | for the internal compression state. memLevel=1 uses minimum memory but | |
465 | is slow and reduces compression ratio; memLevel=9 uses maximum memory | |
466 | for optimal speed. The default value is 8. See zconf.h for total memory | |
467 | usage as a function of windowBits and memLevel. | |
468 | ||
469 | The strategy parameter is used to tune the compression algorithm. Use | |
470 | the value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data | |
471 | produced by a filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman | |
472 | encoding only (no string match). Filtered data consists mostly of small | |
473 | values with a somewhat random distribution. In this case, the | |
474 | compression algorithm is tuned to compress them better. The strategy | |
475 | parameter only affects the compression ratio but not the correctness of | |
476 | the compressed output even if it is not set appropriately. | |
477 | ||
478 | The minCompression parameter specifies the minimum reduction in size | |
479 | required for a compressed block to be output when Z_PACKET_FLUSH is | |
480 | used (see the description of deflate above). | |
481 | ||
482 | If next_in is not null, the library will use this buffer to hold also | |
483 | some history information; the buffer must either hold the entire input | |
484 | data, or have at least 1<<(windowBits+1) bytes and be writable. If next_in | |
485 | is null, the library will allocate its own history buffer (and leave next_in | |
486 | null). next_out need not be provided here but must be provided by the | |
487 | application for the next call of deflate(). | |
488 | ||
489 | If the history buffer is provided by the application, next_in must | |
490 | must never be changed by the application since the compressor maintains | |
491 | information inside this buffer from call to call; the application | |
492 | must provide more input only by increasing avail_in. next_in is always | |
493 | reset by the library in this case. | |
494 | ||
495 | deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was | |
496 | not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as | |
497 | an invalid method). msg is set to null if there is no error message. | |
498 | deflateInit2 does not perform any compression: this will be done by | |
499 | deflate(). | |
500 | */ | |
501 | ||
502 | extern int deflateCopy OF((z_stream *dest, | |
503 | z_stream *source)); | |
504 | /* | |
505 | Sets the destination stream as a complete copy of the source stream. If | |
506 | the source stream is using an application-supplied history buffer, a new | |
507 | buffer is allocated for the destination stream. The compressed output | |
508 | buffer is always application-supplied. It's the responsibility of the | |
509 | application to provide the correct values of next_out and avail_out for the | |
510 | next call of deflate. | |
511 | ||
512 | This function is useful when several compression strategies will be | |
513 | tried, for example when there are several ways of pre-processing the input | |
514 | data with a filter. The streams that will be discarded should then be freed | |
515 | by calling deflateEnd. Note that deflateCopy duplicates the internal | |
516 | compression state which can be quite large, so this strategy is slow and | |
517 | can consume lots of memory. | |
518 | ||
519 | deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | |
520 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | |
521 | (such as zalloc being NULL). msg is left unchanged in both source and | |
522 | destination. | |
523 | */ | |
524 | ||
525 | extern int deflateReset OF((z_stream *strm)); | |
526 | /* | |
527 | This function is equivalent to deflateEnd followed by deflateInit, | |
528 | but does not free and reallocate all the internal compression state. | |
529 | The stream will keep the same compression level and any other attributes | |
530 | that may have been set by deflateInit2. | |
531 | ||
532 | deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | |
533 | stream state was inconsistent (such as zalloc or state being NULL). | |
534 | */ | |
535 | ||
536 | extern int inflateInit2 OF((z_stream *strm, | |
537 | int windowBits)); | |
538 | /* | |
539 | This is another version of inflateInit with more compression options. The | |
540 | fields next_out, zalloc and zfree must be initialized before by the caller. | |
541 | ||
542 | The windowBits parameter is the base two logarithm of the maximum window | |
543 | size (the size of the history buffer). It should be in the range 8..15 for | |
544 | this version of the library (the value 16 will be allowed soon). The | |
545 | default value is 15 if inflateInit is used instead. If a compressed stream | |
546 | with a larger window size is given as input, inflate() will return with | |
547 | the error code Z_DATA_ERROR instead of trying to allocate a larger window. | |
548 | ||
549 | If next_out is not null, the library will use this buffer for the history | |
550 | buffer; the buffer must either be large enough to hold the entire output | |
551 | data, or have at least 1<<windowBits bytes. If next_out is null, the | |
552 | library will allocate its own buffer (and leave next_out null). next_in | |
553 | need not be provided here but must be provided by the application for the | |
554 | next call of inflate(). | |
555 | ||
556 | If the history buffer is provided by the application, next_out must | |
557 | never be changed by the application since the decompressor maintains | |
558 | history information inside this buffer from call to call; the application | |
559 | can only reset next_out to the beginning of the history buffer when | |
560 | avail_out is zero and all output has been consumed. | |
561 | ||
562 | inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was | |
563 | not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as | |
564 | windowBits < 8). msg is set to null if there is no error message. | |
565 | inflateInit2 does not perform any decompression: this will be done by | |
566 | inflate(). | |
567 | */ | |
568 | ||
569 | extern int inflateSync OF((z_stream *strm)); | |
570 | /* | |
571 | Skips invalid compressed data until the special marker (see deflate() | |
572 | above) can be found, or until all available input is skipped. No output | |
573 | is provided. | |
574 | ||
575 | inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR | |
576 | if no more input was provided, Z_DATA_ERROR if no marker has been found, | |
577 | or Z_STREAM_ERROR if the stream structure was inconsistent. In the success | |
578 | case, the application may save the current current value of total_in which | |
579 | indicates where valid compressed data was found. In the error case, the | |
580 | application may repeatedly call inflateSync, providing more input each time, | |
581 | until success or end of the input data. | |
582 | */ | |
583 | ||
584 | extern int inflateReset OF((z_stream *strm)); | |
585 | /* | |
586 | This function is equivalent to inflateEnd followed by inflateInit, | |
587 | but does not free and reallocate all the internal decompression state. | |
588 | The stream will keep attributes that may have been set by inflateInit2. | |
589 | ||
590 | inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | |
591 | stream state was inconsistent (such as zalloc or state being NULL). | |
592 | */ | |
593 | ||
594 | extern int inflateIncomp OF((z_stream *strm)); | |
595 | /* | |
596 | This function adds the data at next_in (avail_in bytes) to the output | |
597 | history without performing any output. There must be no pending output, | |
598 | and the decompressor must be expecting to see the start of a block. | |
599 | Calling this function is equivalent to decompressing a stored block | |
600 | containing the data at next_in (except that the data is not output). | |
601 | */ | |
602 | ||
603 | /* checksum functions */ | |
604 | ||
605 | /* | |
606 | This function is not related to compression but is exported | |
607 | anyway because it might be useful in applications using the | |
608 | compression library. | |
609 | */ | |
610 | ||
611 | extern uLong adler32 OF((uLong adler, Bytef *buf, uInt len)); | |
612 | ||
613 | /* | |
614 | Update a running Adler-32 checksum with the bytes buf[0..len-1] and | |
615 | return the updated checksum. If buf is NULL, this function returns | |
616 | the required initial value for the checksum. | |
617 | An Adler-32 checksum is almost as reliable as a CRC32 but can be computed | |
618 | much faster. Usage example: | |
619 | ||
620 | uLong adler = adler32(0L, Z_NULL, 0); | |
621 | ||
622 | while (read_buffer(buffer, length) != EOF) { | |
623 | adler = adler32(adler, buffer, length); | |
624 | } | |
625 | if (adler != original_adler) error(); | |
626 | */ | |
627 | ||
628 | #ifndef _Z_UTIL_H | |
629 | struct internal_state {int dummy;}; /* hack for buggy compilers */ | |
630 | #endif | |
631 | ||
632 | #endif /* _ZLIB_H */ |