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1 | #ifndef _COMPAT_ZLIB_H |
2 | #define _COMPAT_ZLIB_H | |
3 | ||
4 | #ifdef WANT_ZLIB | |
5 | ||
6 | #ifdef RARCH_INTERNAL | |
7 | #include "zconf.h.in" | |
8 | #endif | |
9 | ||
10 | /* zlib.h -- interface of the 'zlib' general purpose compression library | |
11 | version 1.2.8, April 28th, 2013 | |
12 | ||
13 | Copyright (C) 1995-2013 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 | jloup@gzip.org madler@alumni.caltech.edu | |
33 | ||
34 | The data format used by the zlib library is described by RFCs (Request for | |
35 | Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950 | |
36 | (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). | |
37 | */ | |
38 | ||
39 | #ifndef ZLIB_H | |
40 | #define ZLIB_H | |
41 | ||
42 | #include <stdint.h> | |
43 | #include "zconf.h" | |
44 | ||
45 | #ifdef __cplusplus | |
46 | extern "C" { | |
47 | #endif | |
48 | ||
49 | #define ZLIB_VERSION "1.2.8" | |
50 | #define ZLIB_VERNUM 0x1280 | |
51 | #define ZLIB_VER_MAJOR 1 | |
52 | #define ZLIB_VER_MINOR 2 | |
53 | #define ZLIB_VER_REVISION 8 | |
54 | #define ZLIB_VER_SUBREVISION 0 | |
55 | ||
56 | /* | |
57 | The 'zlib' compression library provides in-memory compression and | |
58 | decompression functions, including integrity checks of the uncompressed data. | |
59 | This version of the library supports only one compression method (deflation) | |
60 | but other algorithms will be added later and will have the same stream | |
61 | interface. | |
62 | ||
63 | Compression can be done in a single step if the buffers are large enough, | |
64 | or can be done by repeated calls of the compression function. In the latter | |
65 | case, the application must provide more input and/or consume the output | |
66 | (providing more output space) before each call. | |
67 | ||
68 | The compressed data format used by default by the in-memory functions is | |
69 | the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped | |
70 | around a deflate stream, which is itself documented in RFC 1951. | |
71 | ||
72 | The library also supports reading and writing files in gzip (.gz) format | |
73 | with an interface similar to that of stdio using the functions that start | |
74 | with "gz". The gzip format is different from the zlib format. gzip is a | |
75 | gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. | |
76 | ||
77 | This library can optionally read and write gzip streams in memory as well. | |
78 | ||
79 | The zlib format was designed to be compact and fast for use in memory | |
80 | and on communications channels. The gzip format was designed for single- | |
81 | file compression on file systems, has a larger header than zlib to maintain | |
82 | directory information, and uses a different, slower check method than zlib. | |
83 | ||
84 | The library does not install any signal handler. The decoder checks | |
85 | the consistency of the compressed data, so the library should never crash | |
86 | even in case of corrupted input. | |
87 | */ | |
88 | ||
89 | typedef voidpf (*alloc_func) (voidpf opaque, uInt items, uInt size); | |
90 | typedef void (*free_func) (voidpf opaque, voidpf address); | |
91 | ||
92 | struct internal_state; | |
93 | ||
94 | typedef struct z_stream_s { | |
95 | z_const Bytef *next_in; /* next input byte */ | |
96 | uInt avail_in; /* number of bytes available at next_in */ | |
97 | uLong total_in; /* total number of input bytes read so far */ | |
98 | ||
99 | Bytef *next_out; /* next output byte should be put there */ | |
100 | uInt avail_out; /* remaining free space at next_out */ | |
101 | uLong total_out; /* total number of bytes output so far */ | |
102 | ||
103 | z_const char *msg; /* last error message, NULL if no error */ | |
104 | void *state; /* not visible by applications */ | |
105 | ||
106 | alloc_func zalloc; /* used to allocate the internal state */ | |
107 | free_func zfree; /* used to free the internal state */ | |
108 | voidpf opaque; /* private data object passed to zalloc and zfree */ | |
109 | ||
110 | int data_type; /* best guess about the data type: binary or text */ | |
111 | uLong adler; /* adler32 value of the uncompressed data */ | |
112 | uLong reserved; /* reserved for future use */ | |
113 | } z_stream; | |
114 | ||
115 | typedef z_stream FAR *z_streamp; | |
116 | ||
117 | /* | |
118 | gzip header information passed to and from zlib routines. See RFC 1952 | |
119 | for more details on the meanings of these fields. | |
120 | */ | |
121 | typedef struct gz_header_s { | |
122 | int text; /* true if compressed data believed to be text */ | |
123 | uLong time; /* modification time */ | |
124 | int xflags; /* extra flags (not used when writing a gzip file) */ | |
125 | int os; /* operating system */ | |
126 | Bytef *extra; /* pointer to extra field or Z_NULL if none */ | |
127 | uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ | |
128 | uInt extra_max; /* space at extra (only when reading header) */ | |
129 | Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ | |
130 | uInt name_max; /* space at name (only when reading header) */ | |
131 | Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ | |
132 | uInt comm_max; /* space at comment (only when reading header) */ | |
133 | int hcrc; /* true if there was or will be a header crc */ | |
134 | int done; /* true when done reading gzip header (not used | |
135 | when writing a gzip file) */ | |
136 | } gz_header; | |
137 | ||
138 | typedef gz_header FAR *gz_headerp; | |
139 | ||
140 | /* | |
141 | The application must update next_in and avail_in when avail_in has dropped | |
142 | to zero. It must update next_out and avail_out when avail_out has dropped | |
143 | to zero. The application must initialize zalloc, zfree and opaque before | |
144 | calling the init function. All other fields are set by the compression | |
145 | library and must not be updated by the application. | |
146 | ||
147 | The opaque value provided by the application will be passed as the first | |
148 | parameter for calls of zalloc and zfree. This can be useful for custom | |
149 | memory management. The compression library attaches no meaning to the | |
150 | opaque value. | |
151 | ||
152 | zalloc must return Z_NULL if there is not enough memory for the object. | |
153 | If zlib is used in a multi-threaded application, zalloc and zfree must be | |
154 | thread safe. | |
155 | ||
156 | On 16-bit systems, the functions zalloc and zfree must be able to allocate | |
157 | exactly 65536 bytes, but will not be required to allocate more than this if | |
158 | the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers | |
159 | returned by zalloc for objects of exactly 65536 bytes *must* have their | |
160 | offset normalized to zero. The default allocation function provided by this | |
161 | library ensures this (see zutil.c). To reduce memory requirements and avoid | |
162 | any allocation of 64K objects, at the expense of compression ratio, compile | |
163 | the library with -DMAX_WBITS=14 (see zconf.h). | |
164 | ||
165 | The fields total_in and total_out can be used for statistics or progress | |
166 | reports. After compression, total_in holds the total size of the | |
167 | uncompressed data and may be saved for use in the decompressor (particularly | |
168 | if the decompressor wants to decompress everything in a single step). | |
169 | */ | |
170 | ||
171 | /* constants */ | |
172 | ||
173 | #define Z_NO_FLUSH 0 | |
174 | #define Z_PARTIAL_FLUSH 1 | |
175 | #define Z_SYNC_FLUSH 2 | |
176 | #define Z_FULL_FLUSH 3 | |
177 | #define Z_FINISH 4 | |
178 | #define Z_BLOCK 5 | |
179 | #define Z_TREES 6 | |
180 | /* Allowed flush values; see deflate() and inflate() below for details */ | |
181 | ||
182 | #define Z_OK 0 | |
183 | #define Z_STREAM_END 1 | |
184 | #define Z_NEED_DICT 2 | |
185 | #define Z_ERRNO (-1) | |
186 | #define Z_STREAM_ERROR (-2) | |
187 | #define Z_DATA_ERROR (-3) | |
188 | #define Z_MEM_ERROR (-4) | |
189 | #define Z_BUF_ERROR (-5) | |
190 | #define Z_VERSION_ERROR (-6) | |
191 | /* Return codes for the compression/decompression functions. Negative values | |
192 | * are errors, positive values are used for special but normal events. | |
193 | */ | |
194 | ||
195 | #define Z_NO_COMPRESSION 0 | |
196 | #define Z_BEST_SPEED 1 | |
197 | #define Z_BEST_COMPRESSION 9 | |
198 | #define Z_DEFAULT_COMPRESSION (-1) | |
199 | /* compression levels */ | |
200 | ||
201 | #define Z_FILTERED 1 | |
202 | #define Z_HUFFMAN_ONLY 2 | |
203 | #define Z_RLE 3 | |
204 | #define Z_FIXED 4 | |
205 | #define Z_DEFAULT_STRATEGY 0 | |
206 | /* compression strategy; see deflateInit2() below for details */ | |
207 | ||
208 | #define Z_BINARY 0 | |
209 | #define Z_TEXT 1 | |
210 | #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ | |
211 | #define Z_UNKNOWN 2 | |
212 | /* Possible values of the data_type field (though see inflate()) */ | |
213 | ||
214 | #define Z_DEFLATED 8 | |
215 | /* The deflate compression method (the only one supported in this version) */ | |
216 | ||
217 | #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ | |
218 | ||
219 | #define zlib_version zlibVersion() | |
220 | /* for compatibility with versions < 1.0.2 */ | |
221 | ||
222 | /* basic functions */ | |
223 | ||
224 | const char * zlibVersion (void); | |
225 | /* The application can compare zlibVersion and ZLIB_VERSION for consistency. | |
226 | If the first character differs, the library code actually used is not | |
227 | compatible with the zlib.h header file used by the application. This check | |
228 | is automatically made by deflateInit and inflateInit. | |
229 | */ | |
230 | ||
231 | /* | |
232 | int deflateInit (z_streamp strm, int level); | |
233 | ||
234 | Initializes the internal stream state for compression. The fields | |
235 | zalloc, zfree and opaque must be initialized before by the caller. If | |
236 | zalloc and zfree are set to Z_NULL, deflateInit updates them to use default | |
237 | allocation functions. | |
238 | ||
239 | The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: | |
240 | 1 gives best speed, 9 gives best compression, 0 gives no compression at all | |
241 | (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION | |
242 | requests a default compromise between speed and compression (currently | |
243 | equivalent to level 6). | |
244 | ||
245 | deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
246 | memory, Z_STREAM_ERROR if level is not a valid compression level, or | |
247 | Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible | |
248 | with the version assumed by the caller (ZLIB_VERSION). msg is set to null | |
249 | if there is no error message. deflateInit does not perform any compression: | |
250 | this will be done by deflate(). | |
251 | */ | |
252 | ||
253 | int deflate (z_streamp strm, int flush); | |
254 | /* | |
255 | deflate compresses as much data as possible, and stops when the input | |
256 | buffer becomes empty or the output buffer becomes full. It may introduce | |
257 | some output latency (reading input without producing any output) except when | |
258 | forced to flush. | |
259 | ||
260 | The detailed semantics are as follows. deflate performs one or both of the | |
261 | following actions: | |
262 | ||
263 | - Compress more input starting at next_in and update next_in and avail_in | |
264 | accordingly. If not all input can be processed (because there is not | |
265 | enough room in the output buffer), next_in and avail_in are updated and | |
266 | processing will resume at this point for the next call of deflate(). | |
267 | ||
268 | - Provide more output starting at next_out and update next_out and avail_out | |
269 | accordingly. This action is forced if the parameter flush is non zero. | |
270 | Forcing flush frequently degrades the compression ratio, so this parameter | |
271 | should be set only when necessary (in interactive applications). Some | |
272 | output may be provided even if flush is not set. | |
273 | ||
274 | Before the call of deflate(), the application should ensure that at least | |
275 | one of the actions is possible, by providing more input and/or consuming more | |
276 | output, and updating avail_in or avail_out accordingly; avail_out should | |
277 | never be zero before the call. The application can consume the compressed | |
278 | output when it wants, for example when the output buffer is full (avail_out | |
279 | == 0), or after each call of deflate(). If deflate returns Z_OK and with | |
280 | zero avail_out, it must be called again after making room in the output | |
281 | buffer because there might be more output pending. | |
282 | ||
283 | Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to | |
284 | decide how much data to accumulate before producing output, in order to | |
285 | maximize compression. | |
286 | ||
287 | If the parameter flush is set to Z_SYNC_FLUSH, all pending output is | |
288 | flushed to the output buffer and the output is aligned on a byte boundary, so | |
289 | that the decompressor can get all input data available so far. (In | |
290 | particular avail_in is zero after the call if enough output space has been | |
291 | provided before the call.) Flushing may degrade compression for some | |
292 | compression algorithms and so it should be used only when necessary. This | |
293 | completes the current deflate block and follows it with an empty stored block | |
294 | that is three bits plus filler bits to the next byte, followed by four bytes | |
295 | (00 00 ff ff). | |
296 | ||
297 | If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the | |
298 | output buffer, but the output is not aligned to a byte boundary. All of the | |
299 | input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. | |
300 | This completes the current deflate block and follows it with an empty fixed | |
301 | codes block that is 10 bits long. This assures that enough bytes are output | |
302 | in order for the decompressor to finish the block before the empty fixed code | |
303 | block. | |
304 | ||
305 | If flush is set to Z_BLOCK, a deflate block is completed and emitted, as | |
306 | for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to | |
307 | seven bits of the current block are held to be written as the next byte after | |
308 | the next deflate block is completed. In this case, the decompressor may not | |
309 | be provided enough bits at this point in order to complete decompression of | |
310 | the data provided so far to the compressor. It may need to wait for the next | |
311 | block to be emitted. This is for advanced applications that need to control | |
312 | the emission of deflate blocks. | |
313 | ||
314 | If flush is set to Z_FULL_FLUSH, all output is flushed as with | |
315 | Z_SYNC_FLUSH, and the compression state is reset so that decompression can | |
316 | restart from this point if previous compressed data has been damaged or if | |
317 | random access is desired. Using Z_FULL_FLUSH too often can seriously degrade | |
318 | compression. | |
319 | ||
320 | If deflate returns with avail_out == 0, this function must be called again | |
321 | with the same value of the flush parameter and more output space (updated | |
322 | avail_out), until the flush is complete (deflate returns with non-zero | |
323 | avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that | |
324 | avail_out is greater than six to avoid repeated flush markers due to | |
325 | avail_out == 0 on return. | |
326 | ||
327 | If the parameter flush is set to Z_FINISH, pending input is processed, | |
328 | pending output is flushed and deflate returns with Z_STREAM_END if there was | |
329 | enough output space; if deflate returns with Z_OK, this function must be | |
330 | called again with Z_FINISH and more output space (updated avail_out) but no | |
331 | more input data, until it returns with Z_STREAM_END or an error. After | |
332 | deflate has returned Z_STREAM_END, the only possible operations on the stream | |
333 | are deflateReset or deflateEnd. | |
334 | ||
335 | Z_FINISH can be used immediately after deflateInit if all the compression | |
336 | is to be done in a single step. In this case, avail_out must be at least the | |
337 | value returned by deflateBound (see below). Then deflate is guaranteed to | |
338 | return Z_STREAM_END. If not enough output space is provided, deflate will | |
339 | not return Z_STREAM_END, and it must be called again as described above. | |
340 | ||
341 | deflate() sets strm->adler to the adler32 checksum of all input read | |
342 | so far (that is, total_in bytes). | |
343 | ||
344 | deflate() may update strm->data_type if it can make a good guess about | |
345 | the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered | |
346 | binary. This field is only for information purposes and does not affect the | |
347 | compression algorithm in any manner. | |
348 | ||
349 | deflate() returns Z_OK if some progress has been made (more input | |
350 | processed or more output produced), Z_STREAM_END if all input has been | |
351 | consumed and all output has been produced (only when flush is set to | |
352 | Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example | |
353 | if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible | |
354 | (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not | |
355 | fatal, and deflate() can be called again with more input and more output | |
356 | space to continue compressing. | |
357 | */ | |
358 | ||
359 | int deflateEnd (z_streamp strm); | |
360 | /* | |
361 | All dynamically allocated data structures for this stream are freed. | |
362 | This function discards any unprocessed input and does not flush any pending | |
363 | output. | |
364 | ||
365 | deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the | |
366 | stream state was inconsistent, Z_DATA_ERROR if the stream was freed | |
367 | prematurely (some input or output was discarded). In the error case, msg | |
368 | may be set but then points to a static string (which must not be | |
369 | deallocated). | |
370 | */ | |
371 | ||
372 | /* | |
373 | int inflateInit (z_streamp strm); | |
374 | ||
375 | Initializes the internal stream state for decompression. The fields | |
376 | next_in, avail_in, zalloc, zfree and opaque must be initialized before by | |
377 | the caller. If next_in is not Z_NULL and avail_in is large enough (the | |
378 | exact value depends on the compression method), inflateInit determines the | |
379 | compression method from the zlib header and allocates all data structures | |
380 | accordingly; otherwise the allocation will be deferred to the first call of | |
381 | inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to | |
382 | use default allocation functions. | |
383 | ||
384 | inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
385 | memory, Z_VERSION_ERROR if the zlib library version is incompatible with the | |
386 | version assumed by the caller, or Z_STREAM_ERROR if the parameters are | |
387 | invalid, such as a null pointer to the structure. msg is set to null if | |
388 | there is no error message. inflateInit does not perform any decompression | |
389 | apart from possibly reading the zlib header if present: actual decompression | |
390 | will be done by inflate(). (So next_in and avail_in may be modified, but | |
391 | next_out and avail_out are unused and unchanged.) The current implementation | |
392 | of inflateInit() does not process any header information -- that is deferred | |
393 | until inflate() is called. | |
394 | */ | |
395 | ||
396 | int inflate (z_streamp strm, int flush); | |
397 | /* | |
398 | inflate decompresses as much data as possible, and stops when the input | |
399 | buffer becomes empty or the output buffer becomes full. It may introduce | |
400 | some output latency (reading input without producing any output) except when | |
401 | forced to flush. | |
402 | ||
403 | The detailed semantics are as follows. inflate performs one or both of the | |
404 | following actions: | |
405 | ||
406 | - Decompress more input starting at next_in and update next_in and avail_in | |
407 | accordingly. If not all input can be processed (because there is not | |
408 | enough room in the output buffer), next_in is updated and processing will | |
409 | resume at this point for the next call of inflate(). | |
410 | ||
411 | - Provide more output starting at next_out and update next_out and avail_out | |
412 | accordingly. inflate() provides as much output as possible, until there is | |
413 | no more input data or no more space in the output buffer (see below about | |
414 | the flush parameter). | |
415 | ||
416 | Before the call of inflate(), the application should ensure that at least | |
417 | one of the actions is possible, by providing more input and/or consuming more | |
418 | output, and updating the next_* and avail_* values accordingly. The | |
419 | application can consume the uncompressed output when it wants, for example | |
420 | when the output buffer is full (avail_out == 0), or after each call of | |
421 | inflate(). If inflate returns Z_OK and with zero avail_out, it must be | |
422 | called again after making room in the output buffer because there might be | |
423 | more output pending. | |
424 | ||
425 | The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, | |
426 | Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much | |
427 | output as possible to the output buffer. Z_BLOCK requests that inflate() | |
428 | stop if and when it gets to the next deflate block boundary. When decoding | |
429 | the zlib or gzip format, this will cause inflate() to return immediately | |
430 | after the header and before the first block. When doing a raw inflate, | |
431 | inflate() will go ahead and process the first block, and will return when it | |
432 | gets to the end of that block, or when it runs out of data. | |
433 | ||
434 | The Z_BLOCK option assists in appending to or combining deflate streams. | |
435 | Also to assist in this, on return inflate() will set strm->data_type to the | |
436 | number of unused bits in the last byte taken from strm->next_in, plus 64 if | |
437 | inflate() is currently decoding the last block in the deflate stream, plus | |
438 | 128 if inflate() returned immediately after decoding an end-of-block code or | |
439 | decoding the complete header up to just before the first byte of the deflate | |
440 | stream. The end-of-block will not be indicated until all of the uncompressed | |
441 | data from that block has been written to strm->next_out. The number of | |
442 | unused bits may in general be greater than seven, except when bit 7 of | |
443 | data_type is set, in which case the number of unused bits will be less than | |
444 | eight. data_type is set as noted here every time inflate() returns for all | |
445 | flush options, and so can be used to determine the amount of currently | |
446 | consumed input in bits. | |
447 | ||
448 | The Z_TREES option behaves as Z_BLOCK does, but it also returns when the | |
449 | end of each deflate block header is reached, before any actual data in that | |
450 | block is decoded. This allows the caller to determine the length of the | |
451 | deflate block header for later use in random access within a deflate block. | |
452 | 256 is added to the value of strm->data_type when inflate() returns | |
453 | immediately after reaching the end of the deflate block header. | |
454 | ||
455 | inflate() should normally be called until it returns Z_STREAM_END or an | |
456 | error. However if all decompression is to be performed in a single step (a | |
457 | single call of inflate), the parameter flush should be set to Z_FINISH. In | |
458 | this case all pending input is processed and all pending output is flushed; | |
459 | avail_out must be large enough to hold all of the uncompressed data for the | |
460 | operation to complete. (The size of the uncompressed data may have been | |
461 | saved by the compressor for this purpose.) The use of Z_FINISH is not | |
462 | required to perform an inflation in one step. However it may be used to | |
463 | inform inflate that a faster approach can be used for the single inflate() | |
464 | call. Z_FINISH also informs inflate to not maintain a sliding window if the | |
465 | stream completes, which reduces inflate's memory footprint. If the stream | |
466 | does not complete, either because not all of the stream is provided or not | |
467 | enough output space is provided, then a sliding window will be allocated and | |
468 | inflate() can be called again to continue the operation as if Z_NO_FLUSH had | |
469 | been used. | |
470 | ||
471 | In this implementation, inflate() always flushes as much output as | |
472 | possible to the output buffer, and always uses the faster approach on the | |
473 | first call. So the effects of the flush parameter in this implementation are | |
474 | on the return value of inflate() as noted below, when inflate() returns early | |
475 | when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of | |
476 | memory for a sliding window when Z_FINISH is used. | |
477 | ||
478 | If a preset dictionary is needed after this call (see inflateSetDictionary | |
479 | below), inflate sets strm->adler to the Adler-32 checksum of the dictionary | |
480 | chosen by the compressor and returns Z_NEED_DICT; otherwise it sets | |
481 | strm->adler to the Adler-32 checksum of all output produced so far (that is, | |
482 | total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described | |
483 | below. At the end of the stream, inflate() checks that its computed adler32 | |
484 | checksum is equal to that saved by the compressor and returns Z_STREAM_END | |
485 | only if the checksum is correct. | |
486 | ||
487 | inflate() can decompress and check either zlib-wrapped or gzip-wrapped | |
488 | deflate data. The header type is detected automatically, if requested when | |
489 | initializing with inflateInit2(). Any information contained in the gzip | |
490 | header is not retained, so applications that need that information should | |
491 | instead use raw inflate, see inflateInit2() below, or inflateBack() and | |
492 | perform their own processing of the gzip header and trailer. When processing | |
493 | gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output | |
494 | producted so far. The CRC-32 is checked against the gzip trailer. | |
495 | ||
496 | inflate() returns Z_OK if some progress has been made (more input processed | |
497 | or more output produced), Z_STREAM_END if the end of the compressed data has | |
498 | been reached and all uncompressed output has been produced, Z_NEED_DICT if a | |
499 | preset dictionary is needed at this point, Z_DATA_ERROR if the input data was | |
500 | corrupted (input stream not conforming to the zlib format or incorrect check | |
501 | value), Z_STREAM_ERROR if the stream structure was inconsistent (for example | |
502 | next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory, | |
503 | Z_BUF_ERROR if no progress is possible or if there was not enough room in the | |
504 | output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and | |
505 | inflate() can be called again with more input and more output space to | |
506 | continue decompressing. If Z_DATA_ERROR is returned, the application may | |
507 | then call inflateSync() to look for a good compression block if a partial | |
508 | recovery of the data is desired. | |
509 | */ | |
510 | ||
511 | int inflateEnd (z_streamp strm); | |
512 | /* | |
513 | All dynamically allocated data structures for this stream are freed. | |
514 | This function discards any unprocessed input and does not flush any pending | |
515 | output. | |
516 | ||
517 | inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state | |
518 | was inconsistent. In the error case, msg may be set but then points to a | |
519 | static string (which must not be deallocated). | |
520 | */ | |
521 | ||
522 | /* Advanced functions */ | |
523 | ||
524 | /* | |
525 | The following functions are needed only in some special applications. | |
526 | */ | |
527 | ||
528 | /* | |
529 | int deflateInit2 (z_streamp strm, | |
530 | int level, | |
531 | int method, | |
532 | int windowBits, | |
533 | int memLevel, | |
534 | int strategy); | |
535 | ||
536 | This is another version of deflateInit with more compression options. The | |
537 | fields next_in, zalloc, zfree and opaque must be initialized before by the | |
538 | caller. | |
539 | ||
540 | The method parameter is the compression method. It must be Z_DEFLATED in | |
541 | this version of the library. | |
542 | ||
543 | The windowBits parameter is the base two logarithm of the window size | |
544 | (the size of the history buffer). It should be in the range 8..15 for this | |
545 | version of the library. Larger values of this parameter result in better | |
546 | compression at the expense of memory usage. The default value is 15 if | |
547 | deflateInit is used instead. | |
548 | ||
549 | windowBits can also be -8..-15 for raw deflate. In this case, -windowBits | |
550 | determines the window size. deflate() will then generate raw deflate data | |
551 | with no zlib header or trailer, and will not compute an adler32 check value. | |
552 | ||
553 | windowBits can also be greater than 15 for optional gzip encoding. Add | |
554 | 16 to windowBits to write a simple gzip header and trailer around the | |
555 | compressed data instead of a zlib wrapper. The gzip header will have no | |
556 | file name, no extra data, no comment, no modification time (set to zero), no | |
557 | header crc, and the operating system will be set to 255 (unknown). If a | |
558 | gzip stream is being written, strm->adler is a crc32 instead of an adler32. | |
559 | ||
560 | The memLevel parameter specifies how much memory should be allocated | |
561 | for the internal compression state. memLevel=1 uses minimum memory but is | |
562 | slow and reduces compression ratio; memLevel=9 uses maximum memory for | |
563 | optimal speed. The default value is 8. See zconf.h for total memory usage | |
564 | as a function of windowBits and memLevel. | |
565 | ||
566 | The strategy parameter is used to tune the compression algorithm. Use the | |
567 | value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a | |
568 | filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no | |
569 | string match), or Z_RLE to limit match distances to one (run-length | |
570 | encoding). Filtered data consists mostly of small values with a somewhat | |
571 | random distribution. In this case, the compression algorithm is tuned to | |
572 | compress them better. The effect of Z_FILTERED is to force more Huffman | |
573 | coding and less string matching; it is somewhat intermediate between | |
574 | Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as | |
575 | fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The | |
576 | strategy parameter only affects the compression ratio but not the | |
577 | correctness of the compressed output even if it is not set appropriately. | |
578 | Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler | |
579 | decoder for special applications. | |
580 | ||
581 | deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
582 | memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid | |
583 | method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is | |
584 | incompatible with the version assumed by the caller (ZLIB_VERSION). msg is | |
585 | set to null if there is no error message. deflateInit2 does not perform any | |
586 | compression: this will be done by deflate(). | |
587 | */ | |
588 | ||
589 | int deflateSetDictionary (z_streamp strm, | |
590 | const Bytef *dictionary, | |
591 | uInt dictLength); | |
592 | /* | |
593 | Initializes the compression dictionary from the given byte sequence | |
594 | without producing any compressed output. When using the zlib format, this | |
595 | function must be called immediately after deflateInit, deflateInit2 or | |
596 | deflateReset, and before any call of deflate. When doing raw deflate, this | |
597 | function must be called either before any call of deflate, or immediately | |
598 | after the completion of a deflate block, i.e. after all input has been | |
599 | consumed and all output has been delivered when using any of the flush | |
600 | options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The | |
601 | compressor and decompressor must use exactly the same dictionary (see | |
602 | inflateSetDictionary). | |
603 | ||
604 | The dictionary should consist of strings (byte sequences) that are likely | |
605 | to be encountered later in the data to be compressed, with the most commonly | |
606 | used strings preferably put towards the end of the dictionary. Using a | |
607 | dictionary is most useful when the data to be compressed is short and can be | |
608 | predicted with good accuracy; the data can then be compressed better than | |
609 | with the default empty dictionary. | |
610 | ||
611 | Depending on the size of the compression data structures selected by | |
612 | deflateInit or deflateInit2, a part of the dictionary may in effect be | |
613 | discarded, for example if the dictionary is larger than the window size | |
614 | provided in deflateInit or deflateInit2. Thus the strings most likely to be | |
615 | useful should be put at the end of the dictionary, not at the front. In | |
616 | addition, the current implementation of deflate will use at most the window | |
617 | size minus 262 bytes of the provided dictionary. | |
618 | ||
619 | Upon return of this function, strm->adler is set to the adler32 value | |
620 | of the dictionary; the decompressor may later use this value to determine | |
621 | which dictionary has been used by the compressor. (The adler32 value | |
622 | applies to the whole dictionary even if only a subset of the dictionary is | |
623 | actually used by the compressor.) If a raw deflate was requested, then the | |
624 | adler32 value is not computed and strm->adler is not set. | |
625 | ||
626 | deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a | |
627 | parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is | |
628 | inconsistent (for example if deflate has already been called for this stream | |
629 | or if not at a block boundary for raw deflate). deflateSetDictionary does | |
630 | not perform any compression: this will be done by deflate(). | |
631 | */ | |
632 | ||
633 | int deflateCopy (z_streamp dest, | |
634 | z_streamp source); | |
635 | /* | |
636 | Sets the destination stream as a complete copy of the source stream. | |
637 | ||
638 | This function can be useful when several compression strategies will be | |
639 | tried, for example when there are several ways of pre-processing the input | |
640 | data with a filter. The streams that will be discarded should then be freed | |
641 | by calling deflateEnd. Note that deflateCopy duplicates the internal | |
642 | compression state which can be quite large, so this strategy is slow and can | |
643 | consume lots of memory. | |
644 | ||
645 | deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | |
646 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | |
647 | (such as zalloc being Z_NULL). msg is left unchanged in both source and | |
648 | destination. | |
649 | */ | |
650 | ||
651 | int deflateReset (z_streamp strm); | |
652 | /* | |
653 | This function is equivalent to deflateEnd followed by deflateInit, | |
654 | but does not free and reallocate all the internal compression state. The | |
655 | stream will keep the same compression level and any other attributes that | |
656 | may have been set by deflateInit2. | |
657 | ||
658 | deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | |
659 | stream state was inconsistent (such as zalloc or state being Z_NULL). | |
660 | */ | |
661 | ||
662 | int deflateParams (z_streamp strm, | |
663 | int level, | |
664 | int strategy); | |
665 | /* | |
666 | Dynamically update the compression level and compression strategy. The | |
667 | interpretation of level and strategy is as in deflateInit2. This can be | |
668 | used to switch between compression and straight copy of the input data, or | |
669 | to switch to a different kind of input data requiring a different strategy. | |
670 | If the compression level is changed, the input available so far is | |
671 | compressed with the old level (and may be flushed); the new level will take | |
672 | effect only at the next call of deflate(). | |
673 | ||
674 | Before the call of deflateParams, the stream state must be set as for | |
675 | a call of deflate(), since the currently available input may have to be | |
676 | compressed and flushed. In particular, strm->avail_out must be non-zero. | |
677 | ||
678 | deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source | |
679 | stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if | |
680 | strm->avail_out was zero. | |
681 | */ | |
682 | ||
683 | int deflateTune (z_streamp strm, | |
684 | int good_length, | |
685 | int max_lazy, | |
686 | int nice_length, | |
687 | int max_chain); | |
688 | /* | |
689 | Fine tune deflate's internal compression parameters. This should only be | |
690 | used by someone who understands the algorithm used by zlib's deflate for | |
691 | searching for the best matching string, and even then only by the most | |
692 | fanatic optimizer trying to squeeze out the last compressed bit for their | |
693 | specific input data. Read the deflate.c source code for the meaning of the | |
694 | max_lazy, good_length, nice_length, and max_chain parameters. | |
695 | ||
696 | deflateTune() can be called after deflateInit() or deflateInit2(), and | |
697 | returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. | |
698 | */ | |
699 | ||
700 | uLong deflateBound (z_streamp strm, | |
701 | uLong sourceLen); | |
702 | /* | |
703 | deflateBound() returns an upper bound on the compressed size after | |
704 | deflation of sourceLen bytes. It must be called after deflateInit() or | |
705 | deflateInit2(), and after deflateSetHeader(), if used. This would be used | |
706 | to allocate an output buffer for deflation in a single pass, and so would be | |
707 | called before deflate(). If that first deflate() call is provided the | |
708 | sourceLen input bytes, an output buffer allocated to the size returned by | |
709 | deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed | |
710 | to return Z_STREAM_END. Note that it is possible for the compressed size to | |
711 | be larger than the value returned by deflateBound() if flush options other | |
712 | than Z_FINISH or Z_NO_FLUSH are used. | |
713 | */ | |
714 | ||
715 | int deflatePending (z_streamp strm, | |
716 | unsigned *pending, | |
717 | int *bits); | |
718 | /* | |
719 | deflatePending() returns the number of bytes and bits of output that have | |
720 | been generated, but not yet provided in the available output. The bytes not | |
721 | provided would be due to the available output space having being consumed. | |
722 | The number of bits of output not provided are between 0 and 7, where they | |
723 | await more bits to join them in order to fill out a full byte. If pending | |
724 | or bits are Z_NULL, then those values are not set. | |
725 | ||
726 | deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source | |
727 | stream state was inconsistent. | |
728 | */ | |
729 | ||
730 | int deflatePrime (z_streamp strm, | |
731 | int bits, | |
732 | int value); | |
733 | /* | |
734 | deflatePrime() inserts bits in the deflate output stream. The intent | |
735 | is that this function is used to start off the deflate output with the bits | |
736 | leftover from a previous deflate stream when appending to it. As such, this | |
737 | function can only be used for raw deflate, and must be used before the first | |
738 | deflate() call after a deflateInit2() or deflateReset(). bits must be less | |
739 | than or equal to 16, and that many of the least significant bits of value | |
740 | will be inserted in the output. | |
741 | ||
742 | deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough | |
743 | room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the | |
744 | source stream state was inconsistent. | |
745 | */ | |
746 | ||
747 | int deflateSetHeader (z_streamp strm, | |
748 | gz_headerp head); | |
749 | /* | |
750 | deflateSetHeader() provides gzip header information for when a gzip | |
751 | stream is requested by deflateInit2(). deflateSetHeader() may be called | |
752 | after deflateInit2() or deflateReset() and before the first call of | |
753 | deflate(). The text, time, os, extra field, name, and comment information | |
754 | in the provided gz_header structure are written to the gzip header (xflag is | |
755 | ignored -- the extra flags are set according to the compression level). The | |
756 | caller must assure that, if not Z_NULL, name and comment are terminated with | |
757 | a zero byte, and that if extra is not Z_NULL, that extra_len bytes are | |
758 | available there. If hcrc is true, a gzip header crc is included. Note that | |
759 | the current versions of the command-line version of gzip (up through version | |
760 | 1.3.x) do not support header crc's, and will report that it is a "multi-part | |
761 | gzip file" and give up. | |
762 | ||
763 | If deflateSetHeader is not used, the default gzip header has text false, | |
764 | the time set to zero, and os set to 255, with no extra, name, or comment | |
765 | fields. The gzip header is returned to the default state by deflateReset(). | |
766 | ||
767 | deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source | |
768 | stream state was inconsistent. | |
769 | */ | |
770 | ||
771 | /* | |
772 | int inflateInit2 (z_streamp strm, | |
773 | int windowBits); | |
774 | ||
775 | This is another version of inflateInit with an extra parameter. The | |
776 | fields next_in, avail_in, zalloc, zfree and opaque must be initialized | |
777 | before by the caller. | |
778 | ||
779 | The windowBits parameter is the base two logarithm of the maximum window | |
780 | size (the size of the history buffer). It should be in the range 8..15 for | |
781 | this version of the library. The default value is 15 if inflateInit is used | |
782 | instead. windowBits must be greater than or equal to the windowBits value | |
783 | provided to deflateInit2() while compressing, or it must be equal to 15 if | |
784 | deflateInit2() was not used. If a compressed stream with a larger window | |
785 | size is given as input, inflate() will return with the error code | |
786 | Z_DATA_ERROR instead of trying to allocate a larger window. | |
787 | ||
788 | windowBits can also be zero to request that inflate use the window size in | |
789 | the zlib header of the compressed stream. | |
790 | ||
791 | windowBits can also be -8..-15 for raw inflate. In this case, -windowBits | |
792 | determines the window size. inflate() will then process raw deflate data, | |
793 | not looking for a zlib or gzip header, not generating a check value, and not | |
794 | looking for any check values for comparison at the end of the stream. This | |
795 | is for use with other formats that use the deflate compressed data format | |
796 | such as zip. Those formats provide their own check values. If a custom | |
797 | format is developed using the raw deflate format for compressed data, it is | |
798 | recommended that a check value such as an adler32 or a crc32 be applied to | |
799 | the uncompressed data as is done in the zlib, gzip, and zip formats. For | |
800 | most applications, the zlib format should be used as is. Note that comments | |
801 | above on the use in deflateInit2() applies to the magnitude of windowBits. | |
802 | ||
803 | windowBits can also be greater than 15 for optional gzip decoding. Add | |
804 | 32 to windowBits to enable zlib and gzip decoding with automatic header | |
805 | detection, or add 16 to decode only the gzip format (the zlib format will | |
806 | return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a | |
807 | crc32 instead of an adler32. | |
808 | ||
809 | inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
810 | memory, Z_VERSION_ERROR if the zlib library version is incompatible with the | |
811 | version assumed by the caller, or Z_STREAM_ERROR if the parameters are | |
812 | invalid, such as a null pointer to the structure. msg is set to null if | |
813 | there is no error message. inflateInit2 does not perform any decompression | |
814 | apart from possibly reading the zlib header if present: actual decompression | |
815 | will be done by inflate(). (So next_in and avail_in may be modified, but | |
816 | next_out and avail_out are unused and unchanged.) The current implementation | |
817 | of inflateInit2() does not process any header information -- that is | |
818 | deferred until inflate() is called. | |
819 | */ | |
820 | ||
821 | int inflateSetDictionary (z_streamp strm, | |
822 | const Bytef *dictionary, | |
823 | uInt dictLength); | |
824 | /* | |
825 | Initializes the decompression dictionary from the given uncompressed byte | |
826 | sequence. This function must be called immediately after a call of inflate, | |
827 | if that call returned Z_NEED_DICT. The dictionary chosen by the compressor | |
828 | can be determined from the adler32 value returned by that call of inflate. | |
829 | The compressor and decompressor must use exactly the same dictionary (see | |
830 | deflateSetDictionary). For raw inflate, this function can be called at any | |
831 | time to set the dictionary. If the provided dictionary is smaller than the | |
832 | window and there is already data in the window, then the provided dictionary | |
833 | will amend what's there. The application must insure that the dictionary | |
834 | that was used for compression is provided. | |
835 | ||
836 | inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a | |
837 | parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is | |
838 | inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the | |
839 | expected one (incorrect adler32 value). inflateSetDictionary does not | |
840 | perform any decompression: this will be done by subsequent calls of | |
841 | inflate(). | |
842 | */ | |
843 | ||
844 | int inflateGetDictionary (z_streamp strm, | |
845 | Bytef *dictionary, | |
846 | uInt *dictLength); | |
847 | /* | |
848 | Returns the sliding dictionary being maintained by inflate. dictLength is | |
849 | set to the number of bytes in the dictionary, and that many bytes are copied | |
850 | to dictionary. dictionary must have enough space, where 32768 bytes is | |
851 | always enough. If inflateGetDictionary() is called with dictionary equal to | |
852 | Z_NULL, then only the dictionary length is returned, and nothing is copied. | |
853 | Similary, if dictLength is Z_NULL, then it is not set. | |
854 | ||
855 | inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the | |
856 | stream state is inconsistent. | |
857 | */ | |
858 | ||
859 | int inflateSync (z_streamp strm); | |
860 | /* | |
861 | Skips invalid compressed data until a possible full flush point (see above | |
862 | for the description of deflate with Z_FULL_FLUSH) can be found, or until all | |
863 | available input is skipped. No output is provided. | |
864 | ||
865 | inflateSync searches for a 00 00 FF FF pattern in the compressed data. | |
866 | All full flush points have this pattern, but not all occurrences of this | |
867 | pattern are full flush points. | |
868 | ||
869 | inflateSync returns Z_OK if a possible full flush point has been found, | |
870 | Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point | |
871 | has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. | |
872 | In the success case, the application may save the current current value of | |
873 | total_in which indicates where valid compressed data was found. In the | |
874 | error case, the application may repeatedly call inflateSync, providing more | |
875 | input each time, until success or end of the input data. | |
876 | */ | |
877 | ||
878 | int inflateCopy (z_streamp dest, | |
879 | z_streamp source); | |
880 | /* | |
881 | Sets the destination stream as a complete copy of the source stream. | |
882 | ||
883 | This function can be useful when randomly accessing a large stream. The | |
884 | first pass through the stream can periodically record the inflate state, | |
885 | allowing restarting inflate at those points when randomly accessing the | |
886 | stream. | |
887 | ||
888 | inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | |
889 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | |
890 | (such as zalloc being Z_NULL). msg is left unchanged in both source and | |
891 | destination. | |
892 | */ | |
893 | ||
894 | int inflateReset (z_streamp strm); | |
895 | /* | |
896 | This function is equivalent to inflateEnd followed by inflateInit, | |
897 | but does not free and reallocate all the internal decompression state. The | |
898 | stream will keep attributes that may have been set by inflateInit2. | |
899 | ||
900 | inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | |
901 | stream state was inconsistent (such as zalloc or state being Z_NULL). | |
902 | */ | |
903 | ||
904 | int inflateReset2 (z_streamp strm, | |
905 | int windowBits); | |
906 | /* | |
907 | This function is the same as inflateReset, but it also permits changing | |
908 | the wrap and window size requests. The windowBits parameter is interpreted | |
909 | the same as it is for inflateInit2. | |
910 | ||
911 | inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source | |
912 | stream state was inconsistent (such as zalloc or state being Z_NULL), or if | |
913 | the windowBits parameter is invalid. | |
914 | */ | |
915 | ||
916 | int inflatePrime (z_streamp strm, | |
917 | int bits, | |
918 | int value); | |
919 | /* | |
920 | This function inserts bits in the inflate input stream. The intent is | |
921 | that this function is used to start inflating at a bit position in the | |
922 | middle of a byte. The provided bits will be used before any bytes are used | |
923 | from next_in. This function should only be used with raw inflate, and | |
924 | should be used before the first inflate() call after inflateInit2() or | |
925 | inflateReset(). bits must be less than or equal to 16, and that many of the | |
926 | least significant bits of value will be inserted in the input. | |
927 | ||
928 | If bits is negative, then the input stream bit buffer is emptied. Then | |
929 | inflatePrime() can be called again to put bits in the buffer. This is used | |
930 | to clear out bits leftover after feeding inflate a block description prior | |
931 | to feeding inflate codes. | |
932 | ||
933 | inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source | |
934 | stream state was inconsistent. | |
935 | */ | |
936 | ||
937 | long inflateMark (z_streamp strm); | |
938 | /* | |
939 | This function returns two values, one in the lower 16 bits of the return | |
940 | value, and the other in the remaining upper bits, obtained by shifting the | |
941 | return value down 16 bits. If the upper value is -1 and the lower value is | |
942 | zero, then inflate() is currently decoding information outside of a block. | |
943 | If the upper value is -1 and the lower value is non-zero, then inflate is in | |
944 | the middle of a stored block, with the lower value equaling the number of | |
945 | bytes from the input remaining to copy. If the upper value is not -1, then | |
946 | it is the number of bits back from the current bit position in the input of | |
947 | the code (literal or length/distance pair) currently being processed. In | |
948 | that case the lower value is the number of bytes already emitted for that | |
949 | code. | |
950 | ||
951 | A code is being processed if inflate is waiting for more input to complete | |
952 | decoding of the code, or if it has completed decoding but is waiting for | |
953 | more output space to write the literal or match data. | |
954 | ||
955 | inflateMark() is used to mark locations in the input data for random | |
956 | access, which may be at bit positions, and to note those cases where the | |
957 | output of a code may span boundaries of random access blocks. The current | |
958 | location in the input stream can be determined from avail_in and data_type | |
959 | as noted in the description for the Z_BLOCK flush parameter for inflate. | |
960 | ||
961 | inflateMark returns the value noted above or -1 << 16 if the provided | |
962 | source stream state was inconsistent. | |
963 | */ | |
964 | ||
965 | int inflateGetHeader (z_streamp strm, | |
966 | gz_headerp head); | |
967 | /* | |
968 | inflateGetHeader() requests that gzip header information be stored in the | |
969 | provided gz_header structure. inflateGetHeader() may be called after | |
970 | inflateInit2() or inflateReset(), and before the first call of inflate(). | |
971 | As inflate() processes the gzip stream, head->done is zero until the header | |
972 | is completed, at which time head->done is set to one. If a zlib stream is | |
973 | being decoded, then head->done is set to -1 to indicate that there will be | |
974 | no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be | |
975 | used to force inflate() to return immediately after header processing is | |
976 | complete and before any actual data is decompressed. | |
977 | ||
978 | The text, time, xflags, and os fields are filled in with the gzip header | |
979 | contents. hcrc is set to true if there is a header CRC. (The header CRC | |
980 | was valid if done is set to one.) If extra is not Z_NULL, then extra_max | |
981 | contains the maximum number of bytes to write to extra. Once done is true, | |
982 | extra_len contains the actual extra field length, and extra contains the | |
983 | extra field, or that field truncated if extra_max is less than extra_len. | |
984 | If name is not Z_NULL, then up to name_max characters are written there, | |
985 | terminated with a zero unless the length is greater than name_max. If | |
986 | comment is not Z_NULL, then up to comm_max characters are written there, | |
987 | terminated with a zero unless the length is greater than comm_max. When any | |
988 | of extra, name, or comment are not Z_NULL and the respective field is not | |
989 | present in the header, then that field is set to Z_NULL to signal its | |
990 | absence. This allows the use of deflateSetHeader() with the returned | |
991 | structure to duplicate the header. However if those fields are set to | |
992 | allocated memory, then the application will need to save those pointers | |
993 | elsewhere so that they can be eventually freed. | |
994 | ||
995 | If inflateGetHeader is not used, then the header information is simply | |
996 | discarded. The header is always checked for validity, including the header | |
997 | CRC if present. inflateReset() will reset the process to discard the header | |
998 | information. The application would need to call inflateGetHeader() again to | |
999 | retrieve the header from the next gzip stream. | |
1000 | ||
1001 | inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source | |
1002 | stream state was inconsistent. | |
1003 | */ | |
1004 | ||
1005 | /* | |
1006 | int inflateBackInit (z_streamp strm, int windowBits, | |
1007 | unsigned char FAR *window); | |
1008 | ||
1009 | Initialize the internal stream state for decompression using inflateBack() | |
1010 | calls. The fields zalloc, zfree and opaque in strm must be initialized | |
1011 | before the call. If zalloc and zfree are Z_NULL, then the default library- | |
1012 | derived memory allocation routines are used. windowBits is the base two | |
1013 | logarithm of the window size, in the range 8..15. window is a caller | |
1014 | supplied buffer of that size. Except for special applications where it is | |
1015 | assured that deflate was used with small window sizes, windowBits must be 15 | |
1016 | and a 32K byte window must be supplied to be able to decompress general | |
1017 | deflate streams. | |
1018 | ||
1019 | See inflateBack() for the usage of these routines. | |
1020 | ||
1021 | inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of | |
1022 | the parameters are invalid, Z_MEM_ERROR if the internal state could not be | |
1023 | allocated, or Z_VERSION_ERROR if the version of the library does not match | |
1024 | the version of the header file. | |
1025 | */ | |
1026 | ||
1027 | typedef unsigned (*in_func) (void FAR *, | |
1028 | z_const unsigned char FAR * FAR *); | |
1029 | typedef int (*out_func) (void FAR *, unsigned char FAR *, unsigned); | |
1030 | ||
1031 | int inflateBack (z_streamp strm, | |
1032 | in_func in, void FAR *in_desc, | |
1033 | out_func out, void FAR *out_desc); | |
1034 | /* | |
1035 | inflateBack() does a raw inflate with a single call using a call-back | |
1036 | interface for input and output. This is potentially more efficient than | |
1037 | inflate() for file i/o applications, in that it avoids copying between the | |
1038 | output and the sliding window by simply making the window itself the output | |
1039 | buffer. inflate() can be faster on modern CPUs when used with large | |
1040 | buffers. inflateBack() trusts the application to not change the output | |
1041 | buffer passed by the output function, at least until inflateBack() returns. | |
1042 | ||
1043 | inflateBackInit() must be called first to allocate the internal state | |
1044 | and to initialize the state with the user-provided window buffer. | |
1045 | inflateBack() may then be used multiple times to inflate a complete, raw | |
1046 | deflate stream with each call. inflateBackEnd() is then called to free the | |
1047 | allocated state. | |
1048 | ||
1049 | A raw deflate stream is one with no zlib or gzip header or trailer. | |
1050 | This routine would normally be used in a utility that reads zip or gzip | |
1051 | files and writes out uncompressed files. The utility would decode the | |
1052 | header and process the trailer on its own, hence this routine expects only | |
1053 | the raw deflate stream to decompress. This is different from the normal | |
1054 | behavior of inflate(), which expects either a zlib or gzip header and | |
1055 | trailer around the deflate stream. | |
1056 | ||
1057 | inflateBack() uses two subroutines supplied by the caller that are then | |
1058 | called by inflateBack() for input and output. inflateBack() calls those | |
1059 | routines until it reads a complete deflate stream and writes out all of the | |
1060 | uncompressed data, or until it encounters an error. The function's | |
1061 | parameters and return types are defined above in the in_func and out_func | |
1062 | typedefs. inflateBack() will call in(in_desc, &buf) which should return the | |
1063 | number of bytes of provided input, and a pointer to that input in buf. If | |
1064 | there is no input available, in() must return zero--buf is ignored in that | |
1065 | case--and inflateBack() will return a buffer error. inflateBack() will call | |
1066 | out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() | |
1067 | should return zero on success, or non-zero on failure. If out() returns | |
1068 | non-zero, inflateBack() will return with an error. Neither in() nor out() | |
1069 | are permitted to change the contents of the window provided to | |
1070 | inflateBackInit(), which is also the buffer that out() uses to write from. | |
1071 | The length written by out() will be at most the window size. Any non-zero | |
1072 | amount of input may be provided by in(). | |
1073 | ||
1074 | For convenience, inflateBack() can be provided input on the first call by | |
1075 | setting strm->next_in and strm->avail_in. If that input is exhausted, then | |
1076 | in() will be called. Therefore strm->next_in must be initialized before | |
1077 | calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called | |
1078 | immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in | |
1079 | must also be initialized, and then if strm->avail_in is not zero, input will | |
1080 | initially be taken from strm->next_in[0 .. strm->avail_in - 1]. | |
1081 | ||
1082 | The in_desc and out_desc parameters of inflateBack() is passed as the | |
1083 | first parameter of in() and out() respectively when they are called. These | |
1084 | descriptors can be optionally used to pass any information that the caller- | |
1085 | supplied in() and out() functions need to do their job. | |
1086 | ||
1087 | On return, inflateBack() will set strm->next_in and strm->avail_in to | |
1088 | pass back any unused input that was provided by the last in() call. The | |
1089 | return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR | |
1090 | if in() or out() returned an error, Z_DATA_ERROR if there was a format error | |
1091 | in the deflate stream (in which case strm->msg is set to indicate the nature | |
1092 | of the error), or Z_STREAM_ERROR if the stream was not properly initialized. | |
1093 | In the case of Z_BUF_ERROR, an input or output error can be distinguished | |
1094 | using strm->next_in which will be Z_NULL only if in() returned an error. If | |
1095 | strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning | |
1096 | non-zero. (in() will always be called before out(), so strm->next_in is | |
1097 | assured to be defined if out() returns non-zero.) Note that inflateBack() | |
1098 | cannot return Z_OK. | |
1099 | */ | |
1100 | ||
1101 | int inflateBackEnd (z_streamp strm); | |
1102 | /* | |
1103 | All memory allocated by inflateBackInit() is freed. | |
1104 | ||
1105 | inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream | |
1106 | state was inconsistent. | |
1107 | */ | |
1108 | ||
1109 | uLong zlibCompileFlags (void); | |
1110 | /* Return flags indicating compile-time options. | |
1111 | ||
1112 | Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: | |
1113 | 1.0: size of uInt | |
1114 | 3.2: size of uLong | |
1115 | 5.4: size of voidpf (pointer) | |
1116 | 7.6: size of z_off_t | |
1117 | ||
1118 | Compiler, assembler, and debug options: | |
1119 | 8: DEBUG | |
1120 | 9: ASMV or ASMINF -- use ASM code | |
1121 | 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention | |
1122 | 11: 0 (reserved) | |
1123 | ||
1124 | One-time table building (smaller code, but not thread-safe if true): | |
1125 | 12: BUILDFIXED -- build static block decoding tables when needed | |
1126 | 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed | |
1127 | 14,15: 0 (reserved) | |
1128 | ||
1129 | Library content (indicates missing functionality): | |
1130 | 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking | |
1131 | deflate code when not needed) | |
1132 | 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect | |
1133 | and decode gzip streams (to avoid linking crc code) | |
1134 | 18-19: 0 (reserved) | |
1135 | ||
1136 | Operation variations (changes in library functionality): | |
1137 | 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate | |
1138 | 21: FASTEST -- deflate algorithm with only one, lowest compression level | |
1139 | 22,23: 0 (reserved) | |
1140 | ||
1141 | The sprintf variant used by gzprintf (zero is best): | |
1142 | 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format | |
1143 | 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! | |
1144 | 26: 0 = returns value, 1 = void -- 1 means inferred string length returned | |
1145 | ||
1146 | Remainder: | |
1147 | 27-31: 0 (reserved) | |
1148 | */ | |
1149 | ||
1150 | #ifndef Z_SOLO | |
1151 | ||
1152 | /* utility functions */ | |
1153 | ||
1154 | /* | |
1155 | The following utility functions are implemented on top of the basic | |
1156 | stream-oriented functions. To simplify the interface, some default options | |
1157 | are assumed (compression level and memory usage, standard memory allocation | |
1158 | functions). The source code of these utility functions can be modified if | |
1159 | you need special options. | |
1160 | */ | |
1161 | ||
1162 | int compress (Bytef *dest, uLongf *destLen, | |
1163 | const Bytef *source, uLong sourceLen); | |
1164 | /* | |
1165 | Compresses the source buffer into the destination buffer. sourceLen is | |
1166 | the byte length of the source buffer. Upon entry, destLen is the total size | |
1167 | of the destination buffer, which must be at least the value returned by | |
1168 | compressBound(sourceLen). Upon exit, destLen is the actual size of the | |
1169 | compressed buffer. | |
1170 | ||
1171 | compress returns Z_OK if success, Z_MEM_ERROR if there was not | |
1172 | enough memory, Z_BUF_ERROR if there was not enough room in the output | |
1173 | buffer. | |
1174 | */ | |
1175 | ||
1176 | int compress2 (Bytef *dest, uLongf *destLen, | |
1177 | const Bytef *source, uLong sourceLen, | |
1178 | int level); | |
1179 | /* | |
1180 | Compresses the source buffer into the destination buffer. The level | |
1181 | parameter has the same meaning as in deflateInit. sourceLen is the byte | |
1182 | length of the source buffer. Upon entry, destLen is the total size of the | |
1183 | destination buffer, which must be at least the value returned by | |
1184 | compressBound(sourceLen). Upon exit, destLen is the actual size of the | |
1185 | compressed buffer. | |
1186 | ||
1187 | compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | |
1188 | memory, Z_BUF_ERROR if there was not enough room in the output buffer, | |
1189 | Z_STREAM_ERROR if the level parameter is invalid. | |
1190 | */ | |
1191 | ||
1192 | uLong compressBound (uLong sourceLen); | |
1193 | /* | |
1194 | compressBound() returns an upper bound on the compressed size after | |
1195 | compress() or compress2() on sourceLen bytes. It would be used before a | |
1196 | compress() or compress2() call to allocate the destination buffer. | |
1197 | */ | |
1198 | ||
1199 | int uncompress (Bytef *dest, uLongf *destLen, | |
1200 | const Bytef *source, uLongf sourceLen); | |
1201 | /* | |
1202 | Decompresses the source buffer into the destination buffer. sourceLen is | |
1203 | the byte length of the source buffer. Upon entry, destLen is the total size | |
1204 | of the destination buffer, which must be large enough to hold the entire | |
1205 | uncompressed data. (The size of the uncompressed data must have been saved | |
1206 | previously by the compressor and transmitted to the decompressor by some | |
1207 | mechanism outside the scope of this compression library.) Upon exit, destLen | |
1208 | is the actual size of the uncompressed buffer. | |
1209 | ||
1210 | uncompress returns Z_OK if success, Z_MEM_ERROR if there was not | |
1211 | enough memory, Z_BUF_ERROR if there was not enough room in the output | |
1212 | buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In | |
1213 | the case where there is not enough room, uncompress() will fill the output | |
1214 | buffer with the uncompressed data up to that point. | |
1215 | */ | |
1216 | ||
1217 | /* gzip file access functions */ | |
1218 | ||
1219 | /* | |
1220 | This library supports reading and writing files in gzip (.gz) format with | |
1221 | an interface similar to that of stdio, using the functions that start with | |
1222 | "gz". The gzip format is different from the zlib format. gzip is a gzip | |
1223 | wrapper, documented in RFC 1952, wrapped around a deflate stream. | |
1224 | */ | |
1225 | ||
1226 | typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ | |
1227 | ||
1228 | /* | |
1229 | gzFile gzopen (const char *path, const char *mode); | |
1230 | ||
1231 | Opens a gzip (.gz) file for reading or writing. The mode parameter is as | |
1232 | in fopen ("rb" or "wb") but can also include a compression level ("wb9") or | |
1233 | a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only | |
1234 | compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' | |
1235 | for fixed code compression as in "wb9F". (See the description of | |
1236 | deflateInit2 for more information about the strategy parameter.) 'T' will | |
1237 | request transparent writing or appending with no compression and not using | |
1238 | the gzip format. | |
1239 | ||
1240 | "a" can be used instead of "w" to request that the gzip stream that will | |
1241 | be written be appended to the file. "+" will result in an error, since | |
1242 | reading and writing to the same gzip file is not supported. The addition of | |
1243 | "x" when writing will create the file exclusively, which fails if the file | |
1244 | already exists. On systems that support it, the addition of "e" when | |
1245 | reading or writing will set the flag to close the file on an execve() call. | |
1246 | ||
1247 | These functions, as well as gzip, will read and decode a sequence of gzip | |
1248 | streams in a file. The append function of gzopen() can be used to create | |
1249 | such a file. (Also see gzflush() for another way to do this.) When | |
1250 | appending, gzopen does not test whether the file begins with a gzip stream, | |
1251 | nor does it look for the end of the gzip streams to begin appending. gzopen | |
1252 | will simply append a gzip stream to the existing file. | |
1253 | ||
1254 | gzopen can be used to read a file which is not in gzip format; in this | |
1255 | case gzread will directly read from the file without decompression. When | |
1256 | reading, this will be detected automatically by looking for the magic two- | |
1257 | byte gzip header. | |
1258 | ||
1259 | gzopen returns NULL if the file could not be opened, if there was | |
1260 | insufficient memory to allocate the gzFile state, or if an invalid mode was | |
1261 | specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). | |
1262 | errno can be checked to determine if the reason gzopen failed was that the | |
1263 | file could not be opened. | |
1264 | */ | |
1265 | ||
1266 | gzFile gzdopen (int fd, const char *mode); | |
1267 | /* | |
1268 | gzdopen associates a gzFile with the file descriptor fd. File descriptors | |
1269 | are obtained from calls like open, dup, creat, pipe or fileno (if the file | |
1270 | has been previously opened with fopen). The mode parameter is as in gzopen. | |
1271 | ||
1272 | The next call of gzclose on the returned gzFile will also close the file | |
1273 | descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor | |
1274 | fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, | |
1275 | mode);. The duplicated descriptor should be saved to avoid a leak, since | |
1276 | gzdopen does not close fd if it fails. If you are using fileno() to get the | |
1277 | file descriptor from a FILE *, then you will have to use dup() to avoid | |
1278 | double-close()ing the file descriptor. Both gzclose() and fclose() will | |
1279 | close the associated file descriptor, so they need to have different file | |
1280 | descriptors. | |
1281 | ||
1282 | gzdopen returns NULL if there was insufficient memory to allocate the | |
1283 | gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not | |
1284 | provided, or '+' was provided), or if fd is -1. The file descriptor is not | |
1285 | used until the next gz* read, write, seek, or close operation, so gzdopen | |
1286 | will not detect if fd is invalid (unless fd is -1). | |
1287 | */ | |
1288 | ||
1289 | int gzbuffer (gzFile file, unsigned size); | |
1290 | /* | |
1291 | Set the internal buffer size used by this library's functions. The | |
1292 | default buffer size is 8192 bytes. This function must be called after | |
1293 | gzopen() or gzdopen(), and before any other calls that read or write the | |
1294 | file. The buffer memory allocation is always deferred to the first read or | |
1295 | write. Two buffers are allocated, either both of the specified size when | |
1296 | writing, or one of the specified size and the other twice that size when | |
1297 | reading. A larger buffer size of, for example, 64K or 128K bytes will | |
1298 | noticeably increase the speed of decompression (reading). | |
1299 | ||
1300 | The new buffer size also affects the maximum length for gzprintf(). | |
1301 | ||
1302 | gzbuffer() returns 0 on success, or -1 on failure, such as being called | |
1303 | too late. | |
1304 | */ | |
1305 | ||
1306 | int gzsetparams (gzFile file, int level, int strategy); | |
1307 | /* | |
1308 | Dynamically update the compression level or strategy. See the description | |
1309 | of deflateInit2 for the meaning of these parameters. | |
1310 | ||
1311 | gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not | |
1312 | opened for writing. | |
1313 | */ | |
1314 | ||
1315 | int gzread (gzFile file, voidp buf, unsigned len); | |
1316 | /* | |
1317 | Reads the given number of uncompressed bytes from the compressed file. If | |
1318 | the input file is not in gzip format, gzread copies the given number of | |
1319 | bytes into the buffer directly from the file. | |
1320 | ||
1321 | After reaching the end of a gzip stream in the input, gzread will continue | |
1322 | to read, looking for another gzip stream. Any number of gzip streams may be | |
1323 | concatenated in the input file, and will all be decompressed by gzread(). | |
1324 | If something other than a gzip stream is encountered after a gzip stream, | |
1325 | that remaining trailing garbage is ignored (and no error is returned). | |
1326 | ||
1327 | gzread can be used to read a gzip file that is being concurrently written. | |
1328 | Upon reaching the end of the input, gzread will return with the available | |
1329 | data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then | |
1330 | gzclearerr can be used to clear the end of file indicator in order to permit | |
1331 | gzread to be tried again. Z_OK indicates that a gzip stream was completed | |
1332 | on the last gzread. Z_BUF_ERROR indicates that the input file ended in the | |
1333 | middle of a gzip stream. Note that gzread does not return -1 in the event | |
1334 | of an incomplete gzip stream. This error is deferred until gzclose(), which | |
1335 | will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip | |
1336 | stream. Alternatively, gzerror can be used before gzclose to detect this | |
1337 | case. | |
1338 | ||
1339 | gzread returns the number of uncompressed bytes actually read, less than | |
1340 | len for end of file, or -1 for error. | |
1341 | */ | |
1342 | ||
1343 | int gzwrite (gzFile file, | |
1344 | voidpc buf, unsigned len); | |
1345 | /* | |
1346 | Writes the given number of uncompressed bytes into the compressed file. | |
1347 | gzwrite returns the number of uncompressed bytes written or 0 in case of | |
1348 | error. | |
1349 | */ | |
1350 | ||
1351 | int gzprintf Z_ARG((gzFile file, const char *format, ...)); | |
1352 | /* | |
1353 | Converts, formats, and writes the arguments to the compressed file under | |
1354 | control of the format string, as in fprintf. gzprintf returns the number of | |
1355 | uncompressed bytes actually written, or 0 in case of error. The number of | |
1356 | uncompressed bytes written is limited to 8191, or one less than the buffer | |
1357 | size given to gzbuffer(). The caller should assure that this limit is not | |
1358 | exceeded. If it is exceeded, then gzprintf() will return an error (0) with | |
1359 | nothing written. In this case, there may also be a buffer overflow with | |
1360 | unpredictable consequences, which is possible only if zlib was compiled with | |
1361 | the insecure functions sprintf() or vsprintf() because the secure snprintf() | |
1362 | or vsnprintf() functions were not available. This can be determined using | |
1363 | zlibCompileFlags(). | |
1364 | */ | |
1365 | ||
1366 | int gzputs (gzFile file, const char *s); | |
1367 | /* | |
1368 | Writes the given null-terminated string to the compressed file, excluding | |
1369 | the terminating null character. | |
1370 | ||
1371 | gzputs returns the number of characters written, or -1 in case of error. | |
1372 | */ | |
1373 | ||
1374 | char * gzgets (gzFile file, char *buf, int len); | |
1375 | /* | |
1376 | Reads bytes from the compressed file until len-1 characters are read, or a | |
1377 | newline character is read and transferred to buf, or an end-of-file | |
1378 | condition is encountered. If any characters are read or if len == 1, the | |
1379 | string is terminated with a null character. If no characters are read due | |
1380 | to an end-of-file or len < 1, then the buffer is left untouched. | |
1381 | ||
1382 | gzgets returns buf which is a null-terminated string, or it returns NULL | |
1383 | for end-of-file or in case of error. If there was an error, the contents at | |
1384 | buf are indeterminate. | |
1385 | */ | |
1386 | ||
1387 | int gzputc (gzFile file, int c); | |
1388 | /* | |
1389 | Writes c, converted to an unsigned char, into the compressed file. gzputc | |
1390 | returns the value that was written, or -1 in case of error. | |
1391 | */ | |
1392 | ||
1393 | int gzgetc (gzFile file); | |
1394 | /* | |
1395 | Reads one byte from the compressed file. gzgetc returns this byte or -1 | |
1396 | in case of end of file or error. This is implemented as a macro for speed. | |
1397 | As such, it does not do all of the checking the other functions do. I.e. | |
1398 | it does not check to see if file is NULL, nor whether the structure file | |
1399 | points to has been clobbered or not. | |
1400 | */ | |
1401 | ||
1402 | int gzungetc (int c, gzFile file); | |
1403 | /* | |
1404 | Push one character back onto the stream to be read as the first character | |
1405 | on the next read. At least one character of push-back is allowed. | |
1406 | gzungetc() returns the character pushed, or -1 on failure. gzungetc() will | |
1407 | fail if c is -1, and may fail if a character has been pushed but not read | |
1408 | yet. If gzungetc is used immediately after gzopen or gzdopen, at least the | |
1409 | output buffer size of pushed characters is allowed. (See gzbuffer above.) | |
1410 | The pushed character will be discarded if the stream is repositioned with | |
1411 | gzseek() or gzrewind(). | |
1412 | */ | |
1413 | ||
1414 | int gzflush (gzFile file, int flush); | |
1415 | /* | |
1416 | Flushes all pending output into the compressed file. The parameter flush | |
1417 | is as in the deflate() function. The return value is the zlib error number | |
1418 | (see function gzerror below). gzflush is only permitted when writing. | |
1419 | ||
1420 | If the flush parameter is Z_FINISH, the remaining data is written and the | |
1421 | gzip stream is completed in the output. If gzwrite() is called again, a new | |
1422 | gzip stream will be started in the output. gzread() is able to read such | |
1423 | concatented gzip streams. | |
1424 | ||
1425 | gzflush should be called only when strictly necessary because it will | |
1426 | degrade compression if called too often. | |
1427 | */ | |
1428 | ||
1429 | /* | |
1430 | z_off_t gzseek (gzFile file, | |
1431 | z_off_t offset, int whence); | |
1432 | ||
1433 | Sets the starting position for the next gzread or gzwrite on the given | |
1434 | compressed file. The offset represents a number of bytes in the | |
1435 | uncompressed data stream. The whence parameter is defined as in lseek(2); | |
1436 | the value SEEK_END is not supported. | |
1437 | ||
1438 | If the file is opened for reading, this function is emulated but can be | |
1439 | extremely slow. If the file is opened for writing, only forward seeks are | |
1440 | supported; gzseek then compresses a sequence of zeroes up to the new | |
1441 | starting position. | |
1442 | ||
1443 | gzseek returns the resulting offset location as measured in bytes from | |
1444 | the beginning of the uncompressed stream, or -1 in case of error, in | |
1445 | particular if the file is opened for writing and the new starting position | |
1446 | would be before the current position. | |
1447 | */ | |
1448 | ||
1449 | int gzrewind (gzFile file); | |
1450 | /* | |
1451 | Rewinds the given file. This function is supported only for reading. | |
1452 | ||
1453 | gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) | |
1454 | */ | |
1455 | ||
1456 | /* | |
1457 | z_off_t gztell (gzFile file); | |
1458 | ||
1459 | Returns the starting position for the next gzread or gzwrite on the given | |
1460 | compressed file. This position represents a number of bytes in the | |
1461 | uncompressed data stream, and is zero when starting, even if appending or | |
1462 | reading a gzip stream from the middle of a file using gzdopen(). | |
1463 | ||
1464 | gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) | |
1465 | */ | |
1466 | ||
1467 | /* | |
1468 | z_off_t gzoffset (gzFile file); | |
1469 | ||
1470 | Returns the current offset in the file being read or written. This offset | |
1471 | includes the count of bytes that precede the gzip stream, for example when | |
1472 | appending or when using gzdopen() for reading. When reading, the offset | |
1473 | does not include as yet unused buffered input. This information can be used | |
1474 | for a progress indicator. On error, gzoffset() returns -1. | |
1475 | */ | |
1476 | ||
1477 | int gzeof (gzFile file); | |
1478 | /* | |
1479 | Returns true (1) if the end-of-file indicator has been set while reading, | |
1480 | false (0) otherwise. Note that the end-of-file indicator is set only if the | |
1481 | read tried to go past the end of the input, but came up short. Therefore, | |
1482 | just like feof(), gzeof() may return false even if there is no more data to | |
1483 | read, in the event that the last read request was for the exact number of | |
1484 | bytes remaining in the input file. This will happen if the input file size | |
1485 | is an exact multiple of the buffer size. | |
1486 | ||
1487 | If gzeof() returns true, then the read functions will return no more data, | |
1488 | unless the end-of-file indicator is reset by gzclearerr() and the input file | |
1489 | has grown since the previous end of file was detected. | |
1490 | */ | |
1491 | ||
1492 | int gzdirect (gzFile file); | |
1493 | /* | |
1494 | Returns true (1) if file is being copied directly while reading, or false | |
1495 | (0) if file is a gzip stream being decompressed. | |
1496 | ||
1497 | If the input file is empty, gzdirect() will return true, since the input | |
1498 | does not contain a gzip stream. | |
1499 | ||
1500 | If gzdirect() is used immediately after gzopen() or gzdopen() it will | |
1501 | cause buffers to be allocated to allow reading the file to determine if it | |
1502 | is a gzip file. Therefore if gzbuffer() is used, it should be called before | |
1503 | gzdirect(). | |
1504 | ||
1505 | When writing, gzdirect() returns true (1) if transparent writing was | |
1506 | requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: | |
1507 | gzdirect() is not needed when writing. Transparent writing must be | |
1508 | explicitly requested, so the application already knows the answer. When | |
1509 | linking statically, using gzdirect() will include all of the zlib code for | |
1510 | gzip file reading and decompression, which may not be desired.) | |
1511 | */ | |
1512 | ||
1513 | int gzclose (gzFile file); | |
1514 | /* | |
1515 | Flushes all pending output if necessary, closes the compressed file and | |
1516 | deallocates the (de)compression state. Note that once file is closed, you | |
1517 | cannot call gzerror with file, since its structures have been deallocated. | |
1518 | gzclose must not be called more than once on the same file, just as free | |
1519 | must not be called more than once on the same allocation. | |
1520 | ||
1521 | gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a | |
1522 | file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the | |
1523 | last read ended in the middle of a gzip stream, or Z_OK on success. | |
1524 | */ | |
1525 | ||
1526 | int gzclose_r (gzFile file); | |
1527 | int gzclose_w (gzFile file); | |
1528 | /* | |
1529 | Same as gzclose(), but gzclose_r() is only for use when reading, and | |
1530 | gzclose_w() is only for use when writing or appending. The advantage to | |
1531 | using these instead of gzclose() is that they avoid linking in zlib | |
1532 | compression or decompression code that is not used when only reading or only | |
1533 | writing respectively. If gzclose() is used, then both compression and | |
1534 | decompression code will be included the application when linking to a static | |
1535 | zlib library. | |
1536 | */ | |
1537 | ||
1538 | const char * gzerror (gzFile file, int *errnum); | |
1539 | /* | |
1540 | Returns the error message for the last error which occurred on the given | |
1541 | compressed file. errnum is set to zlib error number. If an error occurred | |
1542 | in the file system and not in the compression library, errnum is set to | |
1543 | Z_ERRNO and the application may consult errno to get the exact error code. | |
1544 | ||
1545 | The application must not modify the returned string. Future calls to | |
1546 | this function may invalidate the previously returned string. If file is | |
1547 | closed, then the string previously returned by gzerror will no longer be | |
1548 | available. | |
1549 | ||
1550 | gzerror() should be used to distinguish errors from end-of-file for those | |
1551 | functions above that do not distinguish those cases in their return values. | |
1552 | */ | |
1553 | ||
1554 | void gzclearerr (gzFile file); | |
1555 | /* | |
1556 | Clears the error and end-of-file flags for file. This is analogous to the | |
1557 | clearerr() function in stdio. This is useful for continuing to read a gzip | |
1558 | file that is being written concurrently. | |
1559 | */ | |
1560 | ||
1561 | #endif /* !Z_SOLO */ | |
1562 | ||
1563 | /* checksum functions */ | |
1564 | ||
1565 | /* | |
1566 | These functions are not related to compression but are exported | |
1567 | anyway because they might be useful in applications using the compression | |
1568 | library. | |
1569 | */ | |
1570 | ||
1571 | uint32_t adler32 (uint32_t adler, const uint8_t *buf, size_t len); | |
1572 | /* | |
1573 | Update a running Adler-32 checksum with the bytes buf[0..len-1] and | |
1574 | return the updated checksum. If buf is Z_NULL, this function returns the | |
1575 | required initial value for the checksum. | |
1576 | ||
1577 | An Adler-32 checksum is almost as reliable as a CRC32 but can be computed | |
1578 | much faster. | |
1579 | ||
1580 | Usage example: | |
1581 | ||
1582 | uLong adler = adler32(0L, Z_NULL, 0); | |
1583 | ||
1584 | while (read_buffer(buffer, length) != EOF) { | |
1585 | adler = adler32(adler, buffer, length); | |
1586 | } | |
1587 | if (adler != original_adler) error(); | |
1588 | */ | |
1589 | ||
1590 | /* | |
1591 | uLong adler32_combine (uLong adler1, uLong adler2, | |
1592 | z_off_t len2); | |
1593 | ||
1594 | Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 | |
1595 | and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for | |
1596 | each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of | |
1597 | seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note | |
1598 | that the z_off_t type (like off_t) is a signed integer. If len2 is | |
1599 | negative, the result has no meaning or utility. | |
1600 | */ | |
1601 | ||
1602 | uLong crc32 (uLong crc, const Bytef *buf, uInt len); | |
1603 | /* | |
1604 | Update a running CRC-32 with the bytes buf[0..len-1] and return the | |
1605 | updated CRC-32. If buf is Z_NULL, this function returns the required | |
1606 | initial value for the crc. Pre- and post-conditioning (one's complement) is | |
1607 | performed within this function so it shouldn't be done by the application. | |
1608 | ||
1609 | Usage example: | |
1610 | ||
1611 | uLong crc = crc32(0L, Z_NULL, 0); | |
1612 | ||
1613 | while (read_buffer(buffer, length) != EOF) { | |
1614 | crc = crc32(crc, buffer, length); | |
1615 | } | |
1616 | if (crc != original_crc) error(); | |
1617 | */ | |
1618 | ||
1619 | /* | |
1620 | uLong crc32_combine (uLong crc1, uLong crc2, z_off_t len2); | |
1621 | ||
1622 | Combine two CRC-32 check values into one. For two sequences of bytes, | |
1623 | seq1 and seq2 with lengths len1 and len2, CRC-32 check values were | |
1624 | calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 | |
1625 | check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and | |
1626 | len2. | |
1627 | */ | |
1628 | ||
1629 | /* various hacks, don't look :) */ | |
1630 | ||
1631 | /* deflateInit and inflateInit are macros to allow checking the zlib version | |
1632 | * and the compiler's view of z_stream: | |
1633 | */ | |
1634 | int deflateInit_ (z_streamp strm, int level, | |
1635 | const char *version, int stream_size); | |
1636 | int inflateInit_ (z_streamp strm, | |
1637 | const char *version, int stream_size); | |
1638 | int deflateInit2_ (z_streamp strm, int level, int method, | |
1639 | int windowBits, int memLevel, | |
1640 | int strategy, const char *version, | |
1641 | int stream_size); | |
1642 | int inflateInit2_ (z_streamp strm, int windowBits, | |
1643 | const char *version, int stream_size); | |
1644 | int inflateBackInit_ (z_streamp strm, int windowBits, | |
1645 | unsigned char FAR *window, | |
1646 | const char *version, | |
1647 | int stream_size); | |
1648 | #define deflateInit(strm, level) \ | |
1649 | deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) | |
1650 | #define inflateInit(strm) \ | |
1651 | inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) | |
1652 | #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ | |
1653 | deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ | |
1654 | (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) | |
1655 | #define inflateInit2(strm, windowBits) \ | |
1656 | inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ | |
1657 | (int)sizeof(z_stream)) | |
1658 | #define inflateBackInit(strm, windowBits, window) \ | |
1659 | inflateBackInit_((strm), (windowBits), (window), \ | |
1660 | ZLIB_VERSION, (int)sizeof(z_stream)) | |
1661 | ||
1662 | #ifndef Z_SOLO | |
1663 | ||
1664 | /* gzgetc() macro and its supporting function and exposed data structure. Note | |
1665 | * that the real internal state is much larger than the exposed structure. | |
1666 | * This abbreviated structure exposes just enough for the gzgetc() macro. The | |
1667 | * user should not mess with these exposed elements, since their names or | |
1668 | * behavior could change in the future, perhaps even capriciously. They can | |
1669 | * only be used by the gzgetc() macro. You have been warned. | |
1670 | */ | |
1671 | int gzgetc_ (gzFile file); /* backward compatibility */ | |
1672 | #ifdef Z_PREFIX_SET | |
1673 | # undef z_gzgetc | |
1674 | # define z_gzgetc(g) \ | |
1675 | ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) | |
1676 | #else | |
1677 | # define gzgetc(g) \ | |
1678 | ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) | |
1679 | #endif | |
1680 | ||
1681 | /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or | |
1682 | * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if | |
1683 | * both are true, the application gets the *64 functions, and the regular | |
1684 | * functions are changed to 64 bits) -- in case these are set on systems | |
1685 | * without large file support, _LFS64_LARGEFILE must also be true | |
1686 | */ | |
1687 | #ifdef Z_LARGE64 | |
1688 | gzFile gzopen64 (const char *, const char *); | |
1689 | z_off64_t gzseek64 (gzFile, z_off64_t, int); | |
1690 | z_off64_t gztell64 (gzFile); | |
1691 | z_off64_t gzoffset64 (gzFile); | |
1692 | uLong adler32_combine64 (uLong, uLong, z_off64_t); | |
1693 | uLong crc32_combine64 (uLong, uLong, z_off64_t); | |
1694 | #endif | |
1695 | ||
1696 | #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) | |
1697 | # ifdef Z_PREFIX_SET | |
1698 | # define z_gzopen z_gzopen64 | |
1699 | # define z_gzseek z_gzseek64 | |
1700 | # define z_gztell z_gztell64 | |
1701 | # define z_gzoffset z_gzoffset64 | |
1702 | # define z_adler32_combine z_adler32_combine64 | |
1703 | # define z_crc32_combine z_crc32_combine64 | |
1704 | # else | |
1705 | # define gzopen gzopen64 | |
1706 | # define gzseek gzseek64 | |
1707 | # define gztell gztell64 | |
1708 | # define gzoffset gzoffset64 | |
1709 | # define adler32_combine adler32_combine64 | |
1710 | # define crc32_combine crc32_combine64 | |
1711 | # endif | |
1712 | # ifndef Z_LARGE64 | |
1713 | gzFile gzopen64 (const char *, const char *); | |
1714 | z_off_t gzseek64 (gzFile, z_off_t, int); | |
1715 | z_off_t gztell64 (gzFile); | |
1716 | z_off_t gzoffset64 (gzFile); | |
1717 | uLong adler32_combine64 (uLong, uLong, z_off_t); | |
1718 | uLong crc32_combine64 (uLong, uLong, z_off_t); | |
1719 | # endif | |
1720 | #else | |
1721 | gzFile gzopen (const char *, const char *); | |
1722 | z_off_t gzseek (gzFile, z_off_t, int); | |
1723 | z_off_t gztell (gzFile); | |
1724 | z_off_t gzoffset (gzFile); | |
1725 | uLong adler32_combine (uLong, uLong, z_off_t); | |
1726 | uLong crc32_combine (uLong, uLong, z_off_t); | |
1727 | #endif | |
1728 | ||
1729 | #else /* Z_SOLO */ | |
1730 | ||
1731 | uLong adler32_combine (uLong, uLong, z_off_t); | |
1732 | uLong crc32_combine (uLong, uLong, z_off_t); | |
1733 | ||
1734 | #endif /* !Z_SOLO */ | |
1735 | ||
1736 | /* hack for buggy compilers */ | |
1737 | #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) | |
1738 | struct internal_state {int dummy;}; | |
1739 | #endif | |
1740 | ||
1741 | /* undocumented functions */ | |
1742 | const char * zError (int); | |
1743 | int inflateSyncPoint (z_streamp); | |
1744 | ||
1745 | const uint32_t * get_crc_table(void); | |
1746 | int inflateUndermine (z_streamp, int); | |
1747 | int inflateValidate (z_streamp, int); | |
1748 | int inflateResetKeep (z_streamp); | |
1749 | int deflateResetKeep (z_streamp); | |
1750 | #if defined(_WIN32) && !defined(Z_SOLO) | |
1751 | gzFile gzopen_w (const wchar_t *path, | |
1752 | const char *mode); | |
1753 | #endif | |
1754 | #if defined(STDC) || defined(Z_HAVE_STDARG_H) | |
1755 | # ifndef Z_SOLO | |
1756 | int gzvprintf Z_ARG((gzFile file, | |
1757 | const char *format, | |
1758 | va_list va)); | |
1759 | # endif | |
1760 | #endif | |
1761 | ||
1762 | #ifdef __cplusplus | |
1763 | } | |
1764 | #endif | |
1765 | ||
1766 | #endif /* ZLIB_H */ | |
1767 | ||
1768 | #else | |
1769 | #include <zlib.h> | |
1770 | #endif | |
1771 | ||
1772 | #endif |