5784
|
1 |
/* zlib.h -- interface of the 'zlib' general purpose compression library
|
|
2 |
version 1.2.3, July 18th, 2005
|
|
3 |
|
|
4 |
Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
|
|
5 |
|
|
6 |
This software is provided 'as-is', without any express or implied
|
|
7 |
warranty. In no event will the authors be held liable for any damages
|
|
8 |
arising from the use of this software.
|
|
9 |
|
|
10 |
Permission is granted to anyone to use this software for any purpose,
|
|
11 |
including commercial applications, and to alter it and redistribute it
|
|
12 |
freely, subject to the following restrictions:
|
|
13 |
|
|
14 |
1. The origin of this software must not be misrepresented; you must not
|
|
15 |
claim that you wrote the original software. If you use this software
|
|
16 |
in a product, an acknowledgment in the product documentation would be
|
|
17 |
appreciated but is not required.
|
|
18 |
2. Altered source versions must be plainly marked as such, and must not be
|
|
19 |
misrepresented as being the original software.
|
|
20 |
3. This notice may not be removed or altered from any source distribution.
|
|
21 |
|
|
22 |
Jean-loup Gailly Mark Adler
|
|
23 |
jloup@gzip.org madler@alumni.caltech.edu
|
|
24 |
|
|
25 |
|
|
26 |
The data format used by the zlib library is described by RFCs (Request for
|
|
27 |
Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
|
|
28 |
(zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
|
|
29 |
*/
|
|
30 |
|
|
31 |
#ifndef ZLIB_H
|
|
32 |
#define ZLIB_H
|
|
33 |
|
|
34 |
#include "zconf.h"
|
|
35 |
#include "qconfig.h"
|
|
36 |
|
|
37 |
#ifdef __cplusplus
|
|
38 |
extern "C" {
|
|
39 |
#endif
|
|
40 |
|
|
41 |
#define ZLIB_VERSION "1.2.3"
|
|
42 |
#define ZLIB_VERNUM 0x1230
|
|
43 |
|
|
44 |
#if defined(QT_VISIBILITY_AVAILABLE)
|
|
45 |
# define Q_ZEXPORT __attribute__((visibility("default")))
|
|
46 |
#else
|
|
47 |
# ifdef QT_MAKEDLL
|
|
48 |
# define Q_ZEXPORT __declspec(dllexport)
|
|
49 |
# else
|
|
50 |
# define Q_ZEXPORT ZEXPORT
|
|
51 |
# endif
|
|
52 |
#endif
|
|
53 |
|
|
54 |
/*
|
|
55 |
The 'zlib' compression library provides in-memory compression and
|
|
56 |
decompression functions, including integrity checks of the uncompressed
|
|
57 |
data. This version of the library supports only one compression method
|
|
58 |
(deflation) but other algorithms will be added later and will have the same
|
|
59 |
stream interface.
|
|
60 |
|
|
61 |
Compression can be done in a single step if the buffers are large
|
|
62 |
enough (for example if an input file is mmap'ed), or can be done by
|
|
63 |
repeated calls of the compression function. In the latter case, the
|
|
64 |
application must provide more input and/or consume the output
|
|
65 |
(providing more output space) before each call.
|
|
66 |
|
|
67 |
The compressed data format used by default by the in-memory functions is
|
|
68 |
the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
|
|
69 |
around a deflate stream, which is itself documented in RFC 1951.
|
|
70 |
|
|
71 |
The library also supports reading and writing files in gzip (.gz) format
|
|
72 |
with an interface similar to that of stdio using the functions that start
|
|
73 |
with "gz". The gzip format is different from the zlib format. gzip is a
|
|
74 |
gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
|
|
75 |
|
|
76 |
This library can optionally read and write gzip streams in memory as well.
|
|
77 |
|
|
78 |
The zlib format was designed to be compact and fast for use in memory
|
|
79 |
and on communications channels. The gzip format was designed for single-
|
|
80 |
file compression on file systems, has a larger header than zlib to maintain
|
|
81 |
directory information, and uses a different, slower check method than zlib.
|
|
82 |
|
|
83 |
The library does not install any signal handler. The decoder checks
|
|
84 |
the consistency of the compressed data, so the library should never
|
|
85 |
crash even in case of corrupted input.
|
|
86 |
*/
|
|
87 |
|
|
88 |
typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
|
|
89 |
typedef void (*free_func) OF((voidpf opaque, voidpf address));
|
|
90 |
|
|
91 |
struct internal_state;
|
|
92 |
|
|
93 |
typedef struct z_stream_s {
|
|
94 |
Bytef *next_in; /* next input byte */
|
|
95 |
uInt avail_in; /* number of bytes available at next_in */
|
|
96 |
uLong total_in; /* total nb of input bytes read so far */
|
|
97 |
|
|
98 |
Bytef *next_out; /* next output byte should be put there */
|
|
99 |
uInt avail_out; /* remaining free space at next_out */
|
|
100 |
uLong total_out; /* total nb of bytes output so far */
|
|
101 |
|
|
102 |
char *msg; /* last error message, NULL if no error */
|
|
103 |
struct internal_state FAR *state; /* not visible by applications */
|
|
104 |
|
|
105 |
alloc_func zalloc; /* used to allocate the internal state */
|
|
106 |
free_func zfree; /* used to free the internal state */
|
|
107 |
voidpf opaque; /* private data object passed to zalloc and zfree */
|
|
108 |
|
|
109 |
int data_type; /* best guess about the data type: binary or text */
|
|
110 |
uLong adler; /* adler32 value of the uncompressed data */
|
|
111 |
uLong reserved; /* reserved for future use */
|
|
112 |
} z_stream;
|
|
113 |
|
|
114 |
typedef z_stream FAR *z_streamp;
|
|
115 |
|
|
116 |
/*
|
|
117 |
gzip header information passed to and from zlib routines. See RFC 1952
|
|
118 |
for more details on the meanings of these fields.
|
|
119 |
*/
|
|
120 |
typedef struct gz_header_s {
|
|
121 |
int text; /* true if compressed data believed to be text */
|
|
122 |
uLong time; /* modification time */
|
|
123 |
int xflags; /* extra flags (not used when writing a gzip file) */
|
|
124 |
int os; /* operating system */
|
|
125 |
Bytef *extra; /* pointer to extra field or Z_NULL if none */
|
|
126 |
uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
|
|
127 |
uInt extra_max; /* space at extra (only when reading header) */
|
|
128 |
Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
|
|
129 |
uInt name_max; /* space at name (only when reading header) */
|
|
130 |
Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
|
|
131 |
uInt comm_max; /* space at comment (only when reading header) */
|
|
132 |
int hcrc; /* true if there was or will be a header crc */
|
|
133 |
int done; /* true when done reading gzip header (not used
|
|
134 |
when writing a gzip file) */
|
|
135 |
} gz_header;
|
|
136 |
|
|
137 |
typedef gz_header FAR *gz_headerp;
|
|
138 |
|
|
139 |
/*
|
|
140 |
The application must update next_in and avail_in when avail_in has
|
|
141 |
dropped to zero. It must update next_out and avail_out when avail_out
|
|
142 |
has dropped to zero. The application must initialize zalloc, zfree and
|
|
143 |
opaque before calling the init function. All other fields are set by the
|
|
144 |
compression library and must not be updated by the application.
|
|
145 |
|
|
146 |
The opaque value provided by the application will be passed as the first
|
|
147 |
parameter for calls of zalloc and zfree. This can be useful for custom
|
|
148 |
memory management. The compression library attaches no meaning to the
|
|
149 |
opaque value.
|
|
150 |
|
|
151 |
zalloc must return Z_NULL if there is not enough memory for the object.
|
|
152 |
If zlib is used in a multi-threaded application, zalloc and zfree must be
|
|
153 |
thread safe.
|
|
154 |
|
|
155 |
On 16-bit systems, the functions zalloc and zfree must be able to allocate
|
|
156 |
exactly 65536 bytes, but will not be required to allocate more than this
|
|
157 |
if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
|
|
158 |
pointers returned by zalloc for objects of exactly 65536 bytes *must*
|
|
159 |
have their offset normalized to zero. The default allocation function
|
|
160 |
provided by this library ensures this (see zutil.c). To reduce memory
|
|
161 |
requirements and avoid any allocation of 64K objects, at the expense of
|
|
162 |
compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
|
|
163 |
|
|
164 |
The fields total_in and total_out can be used for statistics or
|
|
165 |
progress reports. After compression, total_in holds the total size of
|
|
166 |
the uncompressed data and may be saved for use in the decompressor
|
|
167 |
(particularly if the decompressor wants to decompress everything in
|
|
168 |
a single step).
|
|
169 |
*/
|
|
170 |
|
|
171 |
/* constants */
|
|
172 |
|
|
173 |
#define Z_NO_FLUSH 0
|
|
174 |
#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
|
|
175 |
#define Z_SYNC_FLUSH 2
|
|
176 |
#define Z_FULL_FLUSH 3
|
|
177 |
#define Z_FINISH 4
|
|
178 |
#define Z_BLOCK 5
|
|
179 |
/* Allowed flush values; see deflate() and inflate() below for details */
|
|
180 |
|
|
181 |
#define Z_OK 0
|
|
182 |
#define Z_STREAM_END 1
|
|
183 |
#define Z_NEED_DICT 2
|
|
184 |
#define Z_ERRNO (-1)
|
|
185 |
#define Z_STREAM_ERROR (-2)
|
|
186 |
#define Z_DATA_ERROR (-3)
|
|
187 |
#define Z_MEM_ERROR (-4)
|
|
188 |
#define Z_BUF_ERROR (-5)
|
|
189 |
#define Z_VERSION_ERROR (-6)
|
|
190 |
/* Return codes for the compression/decompression functions. Negative
|
|
191 |
* values are errors, positive values are used for special but normal events.
|
|
192 |
*/
|
|
193 |
|
|
194 |
#define Z_NO_COMPRESSION 0
|
|
195 |
#define Z_BEST_SPEED 1
|
|
196 |
#define Z_BEST_COMPRESSION 9
|
|
197 |
#define Z_DEFAULT_COMPRESSION (-1)
|
|
198 |
/* compression levels */
|
|
199 |
|
|
200 |
#define Z_FILTERED 1
|
|
201 |
#define Z_HUFFMAN_ONLY 2
|
|
202 |
#define Z_RLE 3
|
|
203 |
#define Z_FIXED 4
|
|
204 |
#define Z_DEFAULT_STRATEGY 0
|
|
205 |
/* compression strategy; see deflateInit2() below for details */
|
|
206 |
|
|
207 |
#define Z_BINARY 0
|
|
208 |
#define Z_TEXT 1
|
|
209 |
#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
|
|
210 |
#define Z_UNKNOWN 2
|
|
211 |
/* Possible values of the data_type field (though see inflate()) */
|
|
212 |
|
|
213 |
#define Z_DEFLATED 8
|
|
214 |
/* The deflate compression method (the only one supported in this version) */
|
|
215 |
|
|
216 |
#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
|
|
217 |
|
|
218 |
#define zlib_version zlibVersion()
|
|
219 |
/* for compatibility with versions < 1.0.2 */
|
|
220 |
|
|
221 |
/* basic functions */
|
|
222 |
|
|
223 |
ZEXTERN Q_ZEXPORT const char * zlibVersion OF((void));
|
|
224 |
/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
|
|
225 |
If the first character differs, the library code actually used is
|
|
226 |
not compatible with the zlib.h header file used by the application.
|
|
227 |
This check is automatically made by deflateInit and inflateInit.
|
|
228 |
*/
|
|
229 |
|
|
230 |
/*
|
|
231 |
ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
|
|
232 |
|
|
233 |
Initializes the internal stream state for compression. The fields
|
|
234 |
zalloc, zfree and opaque must be initialized before by the caller.
|
|
235 |
If zalloc and zfree are set to Z_NULL, deflateInit updates them to
|
|
236 |
use default allocation functions.
|
|
237 |
|
|
238 |
The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
|
|
239 |
1 gives best speed, 9 gives best compression, 0 gives no compression at
|
|
240 |
all (the input data is simply copied a block at a time).
|
|
241 |
Z_DEFAULT_COMPRESSION requests a default compromise between speed and
|
|
242 |
compression (currently equivalent to level 6).
|
|
243 |
|
|
244 |
deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
|
|
245 |
enough memory, Z_STREAM_ERROR if level is not a valid compression level,
|
|
246 |
Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
|
|
247 |
with the version assumed by the caller (ZLIB_VERSION).
|
|
248 |
msg is set to null if there is no error message. deflateInit does not
|
|
249 |
perform any compression: this will be done by deflate().
|
|
250 |
*/
|
|
251 |
|
|
252 |
|
|
253 |
ZEXTERN int Q_ZEXPORT deflate OF((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 some
|
|
257 |
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).
|
|
272 |
Some 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
|
|
276 |
more output, and updating avail_in or avail_out accordingly; avail_out
|
|
277 |
should never be zero before the call. The application can consume the
|
|
278 |
compressed output when it wants, for example when the output buffer is full
|
|
279 |
(avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
|
|
280 |
and with zero avail_out, it must be called again after making room in the
|
|
281 |
output 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 accumualte 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 particular
|
|
290 |
avail_in is zero after the call if enough output space has been provided
|
|
291 |
before the call.) Flushing may degrade compression for some compression
|
|
292 |
algorithms and so it should be used only when necessary.
|
|
293 |
|
|
294 |
If flush is set to Z_FULL_FLUSH, all output is flushed as with
|
|
295 |
Z_SYNC_FLUSH, and the compression state is reset so that decompression can
|
|
296 |
restart from this point if previous compressed data has been damaged or if
|
|
297 |
random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
|
|
298 |
compression.
|
|
299 |
|
|
300 |
If deflate returns with avail_out == 0, this function must be called again
|
|
301 |
with the same value of the flush parameter and more output space (updated
|
|
302 |
avail_out), until the flush is complete (deflate returns with non-zero
|
|
303 |
avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
|
|
304 |
avail_out is greater than six to avoid repeated flush markers due to
|
|
305 |
avail_out == 0 on return.
|
|
306 |
|
|
307 |
If the parameter flush is set to Z_FINISH, pending input is processed,
|
|
308 |
pending output is flushed and deflate returns with Z_STREAM_END if there
|
|
309 |
was enough output space; if deflate returns with Z_OK, this function must be
|
|
310 |
called again with Z_FINISH and more output space (updated avail_out) but no
|
|
311 |
more input data, until it returns with Z_STREAM_END or an error. After
|
|
312 |
deflate has returned Z_STREAM_END, the only possible operations on the
|
|
313 |
stream are deflateReset or deflateEnd.
|
|
314 |
|
|
315 |
Z_FINISH can be used immediately after deflateInit if all the compression
|
|
316 |
is to be done in a single step. In this case, avail_out must be at least
|
|
317 |
the value returned by deflateBound (see below). If deflate does not return
|
|
318 |
Z_STREAM_END, then it must be called again as described above.
|
|
319 |
|
|
320 |
deflate() sets strm->adler to the adler32 checksum of all input read
|
|
321 |
so far (that is, total_in bytes).
|
|
322 |
|
|
323 |
deflate() may update strm->data_type if it can make a good guess about
|
|
324 |
the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
|
|
325 |
binary. This field is only for information purposes and does not affect
|
|
326 |
the compression algorithm in any manner.
|
|
327 |
|
|
328 |
deflate() returns Z_OK if some progress has been made (more input
|
|
329 |
processed or more output produced), Z_STREAM_END if all input has been
|
|
330 |
consumed and all output has been produced (only when flush is set to
|
|
331 |
Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
|
|
332 |
if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
|
|
333 |
(for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
|
|
334 |
fatal, and deflate() can be called again with more input and more output
|
|
335 |
space to continue compressing.
|
|
336 |
*/
|
|
337 |
|
|
338 |
|
|
339 |
ZEXTERN int Q_ZEXPORT deflateEnd OF((z_streamp strm));
|
|
340 |
/*
|
|
341 |
All dynamically allocated data structures for this stream are freed.
|
|
342 |
This function discards any unprocessed input and does not flush any
|
|
343 |
pending output.
|
|
344 |
|
|
345 |
deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
|
|
346 |
stream state was inconsistent, Z_DATA_ERROR if the stream was freed
|
|
347 |
prematurely (some input or output was discarded). In the error case,
|
|
348 |
msg may be set but then points to a static string (which must not be
|
|
349 |
deallocated).
|
|
350 |
*/
|
|
351 |
|
|
352 |
|
|
353 |
/*
|
|
354 |
ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
|
|
355 |
|
|
356 |
Initializes the internal stream state for decompression. The fields
|
|
357 |
next_in, avail_in, zalloc, zfree and opaque must be initialized before by
|
|
358 |
the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
|
|
359 |
value depends on the compression method), inflateInit determines the
|
|
360 |
compression method from the zlib header and allocates all data structures
|
|
361 |
accordingly; otherwise the allocation will be deferred to the first call of
|
|
362 |
inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
|
|
363 |
use default allocation functions.
|
|
364 |
|
|
365 |
inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
|
|
366 |
memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
|
|
367 |
version assumed by the caller. msg is set to null if there is no error
|
|
368 |
message. inflateInit does not perform any decompression apart from reading
|
|
369 |
the zlib header if present: this will be done by inflate(). (So next_in and
|
|
370 |
avail_in may be modified, but next_out and avail_out are unchanged.)
|
|
371 |
*/
|
|
372 |
|
|
373 |
|
|
374 |
ZEXTERN int Q_ZEXPORT inflate OF((z_streamp strm, int flush));
|
|
375 |
/*
|
|
376 |
inflate decompresses as much data as possible, and stops when the input
|
|
377 |
buffer becomes empty or the output buffer becomes full. It may introduce
|
|
378 |
some output latency (reading input without producing any output) except when
|
|
379 |
forced to flush.
|
|
380 |
|
|
381 |
The detailed semantics are as follows. inflate performs one or both of the
|
|
382 |
following actions:
|
|
383 |
|
|
384 |
- Decompress more input starting at next_in and update next_in and avail_in
|
|
385 |
accordingly. If not all input can be processed (because there is not
|
|
386 |
enough room in the output buffer), next_in is updated and processing
|
|
387 |
will resume at this point for the next call of inflate().
|
|
388 |
|
|
389 |
- Provide more output starting at next_out and update next_out and avail_out
|
|
390 |
accordingly. inflate() provides as much output as possible, until there
|
|
391 |
is no more input data or no more space in the output buffer (see below
|
|
392 |
about the flush parameter).
|
|
393 |
|
|
394 |
Before the call of inflate(), the application should ensure that at least
|
|
395 |
one of the actions is possible, by providing more input and/or consuming
|
|
396 |
more output, and updating the next_* and avail_* values accordingly.
|
|
397 |
The application can consume the uncompressed output when it wants, for
|
|
398 |
example when the output buffer is full (avail_out == 0), or after each
|
|
399 |
call of inflate(). If inflate returns Z_OK and with zero avail_out, it
|
|
400 |
must be called again after making room in the output buffer because there
|
|
401 |
might be more output pending.
|
|
402 |
|
|
403 |
The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
|
|
404 |
Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
|
|
405 |
output as possible to the output buffer. Z_BLOCK requests that inflate() stop
|
|
406 |
if and when it gets to the next deflate block boundary. When decoding the
|
|
407 |
zlib or gzip format, this will cause inflate() to return immediately after
|
|
408 |
the header and before the first block. When doing a raw inflate, inflate()
|
|
409 |
will go ahead and process the first block, and will return when it gets to
|
|
410 |
the end of that block, or when it runs out of data.
|
|
411 |
|
|
412 |
The Z_BLOCK option assists in appending to or combining deflate streams.
|
|
413 |
Also to assist in this, on return inflate() will set strm->data_type to the
|
|
414 |
number of unused bits in the last byte taken from strm->next_in, plus 64
|
|
415 |
if inflate() is currently decoding the last block in the deflate stream,
|
|
416 |
plus 128 if inflate() returned immediately after decoding an end-of-block
|
|
417 |
code or decoding the complete header up to just before the first byte of the
|
|
418 |
deflate stream. The end-of-block will not be indicated until all of the
|
|
419 |
uncompressed data from that block has been written to strm->next_out. The
|
|
420 |
number of unused bits may in general be greater than seven, except when
|
|
421 |
bit 7 of data_type is set, in which case the number of unused bits will be
|
|
422 |
less than eight.
|
|
423 |
|
|
424 |
inflate() should normally be called until it returns Z_STREAM_END or an
|
|
425 |
error. However if all decompression is to be performed in a single step
|
|
426 |
(a single call of inflate), the parameter flush should be set to
|
|
427 |
Z_FINISH. In this case all pending input is processed and all pending
|
|
428 |
output is flushed; avail_out must be large enough to hold all the
|
|
429 |
uncompressed data. (The size of the uncompressed data may have been saved
|
|
430 |
by the compressor for this purpose.) The next operation on this stream must
|
|
431 |
be inflateEnd to deallocate the decompression state. The use of Z_FINISH
|
|
432 |
is never required, but can be used to inform inflate that a faster approach
|
|
433 |
may be used for the single inflate() call.
|
|
434 |
|
|
435 |
In this implementation, inflate() always flushes as much output as
|
|
436 |
possible to the output buffer, and always uses the faster approach on the
|
|
437 |
first call. So the only effect of the flush parameter in this implementation
|
|
438 |
is on the return value of inflate(), as noted below, or when it returns early
|
|
439 |
because Z_BLOCK is used.
|
|
440 |
|
|
441 |
If a preset dictionary is needed after this call (see inflateSetDictionary
|
|
442 |
below), inflate sets strm->adler to the adler32 checksum of the dictionary
|
|
443 |
chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
|
|
444 |
strm->adler to the adler32 checksum of all output produced so far (that is,
|
|
445 |
total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
|
|
446 |
below. At the end of the stream, inflate() checks that its computed adler32
|
|
447 |
checksum is equal to that saved by the compressor and returns Z_STREAM_END
|
|
448 |
only if the checksum is correct.
|
|
449 |
|
|
450 |
inflate() will decompress and check either zlib-wrapped or gzip-wrapped
|
|
451 |
deflate data. The header type is detected automatically. Any information
|
|
452 |
contained in the gzip header is not retained, so applications that need that
|
|
453 |
information should instead use raw inflate, see inflateInit2() below, or
|
|
454 |
inflateBack() and perform their own processing of the gzip header and
|
|
455 |
trailer.
|
|
456 |
|
|
457 |
inflate() returns Z_OK if some progress has been made (more input processed
|
|
458 |
or more output produced), Z_STREAM_END if the end of the compressed data has
|
|
459 |
been reached and all uncompressed output has been produced, Z_NEED_DICT if a
|
|
460 |
preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
|
|
461 |
corrupted (input stream not conforming to the zlib format or incorrect check
|
|
462 |
value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
|
|
463 |
if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
|
|
464 |
Z_BUF_ERROR if no progress is possible or if there was not enough room in the
|
|
465 |
output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
|
|
466 |
inflate() can be called again with more input and more output space to
|
|
467 |
continue decompressing. If Z_DATA_ERROR is returned, the application may then
|
|
468 |
call inflateSync() to look for a good compression block if a partial recovery
|
|
469 |
of the data is desired.
|
|
470 |
*/
|
|
471 |
|
|
472 |
|
|
473 |
ZEXTERN int Q_ZEXPORT inflateEnd OF((z_streamp strm));
|
|
474 |
/*
|
|
475 |
All dynamically allocated data structures for this stream are freed.
|
|
476 |
This function discards any unprocessed input and does not flush any
|
|
477 |
pending output.
|
|
478 |
|
|
479 |
inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
|
|
480 |
was inconsistent. In the error case, msg may be set but then points to a
|
|
481 |
static string (which must not be deallocated).
|
|
482 |
*/
|
|
483 |
|
|
484 |
/* Advanced functions */
|
|
485 |
|
|
486 |
/*
|
|
487 |
The following functions are needed only in some special applications.
|
|
488 |
*/
|
|
489 |
|
|
490 |
/*
|
|
491 |
ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
|
|
492 |
int level,
|
|
493 |
int method,
|
|
494 |
int windowBits,
|
|
495 |
int memLevel,
|
|
496 |
int strategy));
|
|
497 |
|
|
498 |
This is another version of deflateInit with more compression options. The
|
|
499 |
fields next_in, zalloc, zfree and opaque must be initialized before by
|
|
500 |
the caller.
|
|
501 |
|
|
502 |
The method parameter is the compression method. It must be Z_DEFLATED in
|
|
503 |
this version of the library.
|
|
504 |
|
|
505 |
The windowBits parameter is the base two logarithm of the window size
|
|
506 |
(the size of the history buffer). It should be in the range 8..15 for this
|
|
507 |
version of the library. Larger values of this parameter result in better
|
|
508 |
compression at the expense of memory usage. The default value is 15 if
|
|
509 |
deflateInit is used instead.
|
|
510 |
|
|
511 |
windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
|
|
512 |
determines the window size. deflate() will then generate raw deflate data
|
|
513 |
with no zlib header or trailer, and will not compute an adler32 check value.
|
|
514 |
|
|
515 |
windowBits can also be greater than 15 for optional gzip encoding. Add
|
|
516 |
16 to windowBits to write a simple gzip header and trailer around the
|
|
517 |
compressed data instead of a zlib wrapper. The gzip header will have no
|
|
518 |
file name, no extra data, no comment, no modification time (set to zero),
|
|
519 |
no header crc, and the operating system will be set to 255 (unknown). If a
|
|
520 |
gzip stream is being written, strm->adler is a crc32 instead of an adler32.
|
|
521 |
|
|
522 |
The memLevel parameter specifies how much memory should be allocated
|
|
523 |
for the internal compression state. memLevel=1 uses minimum memory but
|
|
524 |
is slow and reduces compression ratio; memLevel=9 uses maximum memory
|
|
525 |
for optimal speed. The default value is 8. See zconf.h for total memory
|
|
526 |
usage as a function of windowBits and memLevel.
|
|
527 |
|
|
528 |
The strategy parameter is used to tune the compression algorithm. Use the
|
|
529 |
value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
|
|
530 |
filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
|
|
531 |
string match), or Z_RLE to limit match distances to one (run-length
|
|
532 |
encoding). Filtered data consists mostly of small values with a somewhat
|
|
533 |
random distribution. In this case, the compression algorithm is tuned to
|
|
534 |
compress them better. The effect of Z_FILTERED is to force more Huffman
|
|
535 |
coding and less string matching; it is somewhat intermediate between
|
|
536 |
Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
|
|
537 |
Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
|
|
538 |
parameter only affects the compression ratio but not the correctness of the
|
|
539 |
compressed output even if it is not set appropriately. Z_FIXED prevents the
|
|
540 |
use of dynamic Huffman codes, allowing for a simpler decoder for special
|
|
541 |
applications.
|
|
542 |
|
|
543 |
deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
|
|
544 |
memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
|
|
545 |
method). msg is set to null if there is no error message. deflateInit2 does
|
|
546 |
not perform any compression: this will be done by deflate().
|
|
547 |
*/
|
|
548 |
|
|
549 |
ZEXTERN int Q_ZEXPORT deflateSetDictionary OF((z_streamp strm,
|
|
550 |
const Bytef *dictionary,
|
|
551 |
uInt dictLength));
|
|
552 |
/*
|
|
553 |
Initializes the compression dictionary from the given byte sequence
|
|
554 |
without producing any compressed output. This function must be called
|
|
555 |
immediately after deflateInit, deflateInit2 or deflateReset, before any
|
|
556 |
call of deflate. The compressor and decompressor must use exactly the same
|
|
557 |
dictionary (see inflateSetDictionary).
|
|
558 |
|
|
559 |
The dictionary should consist of strings (byte sequences) that are likely
|
|
560 |
to be encountered later in the data to be compressed, with the most commonly
|
|
561 |
used strings preferably put towards the end of the dictionary. Using a
|
|
562 |
dictionary is most useful when the data to be compressed is short and can be
|
|
563 |
predicted with good accuracy; the data can then be compressed better than
|
|
564 |
with the default empty dictionary.
|
|
565 |
|
|
566 |
Depending on the size of the compression data structures selected by
|
|
567 |
deflateInit or deflateInit2, a part of the dictionary may in effect be
|
|
568 |
discarded, for example if the dictionary is larger than the window size in
|
|
569 |
deflate or deflate2. Thus the strings most likely to be useful should be
|
|
570 |
put at the end of the dictionary, not at the front. In addition, the
|
|
571 |
current implementation of deflate will use at most the window size minus
|
|
572 |
262 bytes of the provided dictionary.
|
|
573 |
|
|
574 |
Upon return of this function, strm->adler is set to the adler32 value
|
|
575 |
of the dictionary; the decompressor may later use this value to determine
|
|
576 |
which dictionary has been used by the compressor. (The adler32 value
|
|
577 |
applies to the whole dictionary even if only a subset of the dictionary is
|
|
578 |
actually used by the compressor.) If a raw deflate was requested, then the
|
|
579 |
adler32 value is not computed and strm->adler is not set.
|
|
580 |
|
|
581 |
deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
|
|
582 |
parameter is invalid (such as NULL dictionary) or the stream state is
|
|
583 |
inconsistent (for example if deflate has already been called for this stream
|
|
584 |
or if the compression method is bsort). deflateSetDictionary does not
|
|
585 |
perform any compression: this will be done by deflate().
|
|
586 |
*/
|
|
587 |
|
|
588 |
ZEXTERN int Q_ZEXPORT deflateCopy OF((z_streamp dest,
|
|
589 |
z_streamp source));
|
|
590 |
/*
|
|
591 |
Sets the destination stream as a complete copy of the source stream.
|
|
592 |
|
|
593 |
This function can be useful when several compression strategies will be
|
|
594 |
tried, for example when there are several ways of pre-processing the input
|
|
595 |
data with a filter. The streams that will be discarded should then be freed
|
|
596 |
by calling deflateEnd. Note that deflateCopy duplicates the internal
|
|
597 |
compression state which can be quite large, so this strategy is slow and
|
|
598 |
can consume lots of memory.
|
|
599 |
|
|
600 |
deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
|
|
601 |
enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
|
|
602 |
(such as zalloc being NULL). msg is left unchanged in both source and
|
|
603 |
destination.
|
|
604 |
*/
|
|
605 |
|
|
606 |
ZEXTERN int Q_ZEXPORT deflateReset OF((z_streamp strm));
|
|
607 |
/*
|
|
608 |
This function is equivalent to deflateEnd followed by deflateInit,
|
|
609 |
but does not free and reallocate all the internal compression state.
|
|
610 |
The stream will keep the same compression level and any other attributes
|
|
611 |
that may have been set by deflateInit2.
|
|
612 |
|
|
613 |
deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
|
|
614 |
stream state was inconsistent (such as zalloc or state being NULL).
|
|
615 |
*/
|
|
616 |
|
|
617 |
ZEXTERN int Q_ZEXPORT deflateParams OF((z_streamp strm,
|
|
618 |
int level,
|
|
619 |
int strategy));
|
|
620 |
/*
|
|
621 |
Dynamically update the compression level and compression strategy. The
|
|
622 |
interpretation of level and strategy is as in deflateInit2. This can be
|
|
623 |
used to switch between compression and straight copy of the input data, or
|
|
624 |
to switch to a different kind of input data requiring a different
|
|
625 |
strategy. If the compression level is changed, the input available so far
|
|
626 |
is compressed with the old level (and may be flushed); the new level will
|
|
627 |
take effect only at the next call of deflate().
|
|
628 |
|
|
629 |
Before the call of deflateParams, the stream state must be set as for
|
|
630 |
a call of deflate(), since the currently available input may have to
|
|
631 |
be compressed and flushed. In particular, strm->avail_out must be non-zero.
|
|
632 |
|
|
633 |
deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
|
|
634 |
stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
|
|
635 |
if strm->avail_out was zero.
|
|
636 |
*/
|
|
637 |
|
|
638 |
ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
|
|
639 |
int good_length,
|
|
640 |
int max_lazy,
|
|
641 |
int nice_length,
|
|
642 |
int max_chain));
|
|
643 |
/*
|
|
644 |
Fine tune deflate's internal compression parameters. This should only be
|
|
645 |
used by someone who understands the algorithm used by zlib's deflate for
|
|
646 |
searching for the best matching string, and even then only by the most
|
|
647 |
fanatic optimizer trying to squeeze out the last compressed bit for their
|
|
648 |
specific input data. Read the deflate.c source code for the meaning of the
|
|
649 |
max_lazy, good_length, nice_length, and max_chain parameters.
|
|
650 |
|
|
651 |
deflateTune() can be called after deflateInit() or deflateInit2(), and
|
|
652 |
returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
|
|
653 |
*/
|
|
654 |
|
|
655 |
ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
|
|
656 |
uLong sourceLen));
|
|
657 |
/*
|
|
658 |
deflateBound() returns an upper bound on the compressed size after
|
|
659 |
deflation of sourceLen bytes. It must be called after deflateInit()
|
|
660 |
or deflateInit2(). This would be used to allocate an output buffer
|
|
661 |
for deflation in a single pass, and so would be called before deflate().
|
|
662 |
*/
|
|
663 |
|
|
664 |
ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
|
|
665 |
int bits,
|
|
666 |
int value));
|
|
667 |
/*
|
|
668 |
deflatePrime() inserts bits in the deflate output stream. The intent
|
|
669 |
is that this function is used to start off the deflate output with the
|
|
670 |
bits leftover from a previous deflate stream when appending to it. As such,
|
|
671 |
this function can only be used for raw deflate, and must be used before the
|
|
672 |
first deflate() call after a deflateInit2() or deflateReset(). bits must be
|
|
673 |
less than or equal to 16, and that many of the least significant bits of
|
|
674 |
value will be inserted in the output.
|
|
675 |
|
|
676 |
deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
|
|
677 |
stream state was inconsistent.
|
|
678 |
*/
|
|
679 |
|
|
680 |
ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
|
|
681 |
gz_headerp head));
|
|
682 |
/*
|
|
683 |
deflateSetHeader() provides gzip header information for when a gzip
|
|
684 |
stream is requested by deflateInit2(). deflateSetHeader() may be called
|
|
685 |
after deflateInit2() or deflateReset() and before the first call of
|
|
686 |
deflate(). The text, time, os, extra field, name, and comment information
|
|
687 |
in the provided gz_header structure are written to the gzip header (xflag is
|
|
688 |
ignored -- the extra flags are set according to the compression level). The
|
|
689 |
caller must assure that, if not Z_NULL, name and comment are terminated with
|
|
690 |
a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
|
|
691 |
available there. If hcrc is true, a gzip header crc is included. Note that
|
|
692 |
the current versions of the command-line version of gzip (up through version
|
|
693 |
1.3.x) do not support header crc's, and will report that it is a "multi-part
|
|
694 |
gzip file" and give up.
|
|
695 |
|
|
696 |
If deflateSetHeader is not used, the default gzip header has text false,
|
|
697 |
the time set to zero, and os set to 255, with no extra, name, or comment
|
|
698 |
fields. The gzip header is returned to the default state by deflateReset().
|
|
699 |
|
|
700 |
deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
|
|
701 |
stream state was inconsistent.
|
|
702 |
*/
|
|
703 |
|
|
704 |
/*
|
|
705 |
ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
|
|
706 |
int windowBits));
|
|
707 |
|
|
708 |
This is another version of inflateInit with an extra parameter. The
|
|
709 |
fields next_in, avail_in, zalloc, zfree and opaque must be initialized
|
|
710 |
before by the caller.
|
|
711 |
|
|
712 |
The windowBits parameter is the base two logarithm of the maximum window
|
|
713 |
size (the size of the history buffer). It should be in the range 8..15 for
|
|
714 |
this version of the library. The default value is 15 if inflateInit is used
|
|
715 |
instead. windowBits must be greater than or equal to the windowBits value
|
|
716 |
provided to deflateInit2() while compressing, or it must be equal to 15 if
|
|
717 |
deflateInit2() was not used. If a compressed stream with a larger window
|
|
718 |
size is given as input, inflate() will return with the error code
|
|
719 |
Z_DATA_ERROR instead of trying to allocate a larger window.
|
|
720 |
|
|
721 |
windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
|
|
722 |
determines the window size. inflate() will then process raw deflate data,
|
|
723 |
not looking for a zlib or gzip header, not generating a check value, and not
|
|
724 |
looking for any check values for comparison at the end of the stream. This
|
|
725 |
is for use with other formats that use the deflate compressed data format
|
|
726 |
such as zip. Those formats provide their own check values. If a custom
|
|
727 |
format is developed using the raw deflate format for compressed data, it is
|
|
728 |
recommended that a check value such as an adler32 or a crc32 be applied to
|
|
729 |
the uncompressed data as is done in the zlib, gzip, and zip formats. For
|
|
730 |
most applications, the zlib format should be used as is. Note that comments
|
|
731 |
above on the use in deflateInit2() applies to the magnitude of windowBits.
|
|
732 |
|
|
733 |
windowBits can also be greater than 15 for optional gzip decoding. Add
|
|
734 |
32 to windowBits to enable zlib and gzip decoding with automatic header
|
|
735 |
detection, or add 16 to decode only the gzip format (the zlib format will
|
|
736 |
return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is
|
|
737 |
a crc32 instead of an adler32.
|
|
738 |
|
|
739 |
inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
|
|
740 |
memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg
|
|
741 |
is set to null if there is no error message. inflateInit2 does not perform
|
|
742 |
any decompression apart from reading the zlib header if present: this will
|
|
743 |
be done by inflate(). (So next_in and avail_in may be modified, but next_out
|
|
744 |
and avail_out are unchanged.)
|
|
745 |
*/
|
|
746 |
|
|
747 |
ZEXTERN int Q_ZEXPORT inflateSetDictionary OF((z_streamp strm,
|
|
748 |
const Bytef *dictionary,
|
|
749 |
uInt dictLength));
|
|
750 |
/*
|
|
751 |
Initializes the decompression dictionary from the given uncompressed byte
|
|
752 |
sequence. This function must be called immediately after a call of inflate,
|
|
753 |
if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
|
|
754 |
can be determined from the adler32 value returned by that call of inflate.
|
|
755 |
The compressor and decompressor must use exactly the same dictionary (see
|
|
756 |
deflateSetDictionary). For raw inflate, this function can be called
|
|
757 |
immediately after inflateInit2() or inflateReset() and before any call of
|
|
758 |
inflate() to set the dictionary. The application must insure that the
|
|
759 |
dictionary that was used for compression is provided.
|
|
760 |
|
|
761 |
inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
|
|
762 |
parameter is invalid (such as NULL dictionary) or the stream state is
|
|
763 |
inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
|
|
764 |
expected one (incorrect adler32 value). inflateSetDictionary does not
|
|
765 |
perform any decompression: this will be done by subsequent calls of
|
|
766 |
inflate().
|
|
767 |
*/
|
|
768 |
|
|
769 |
ZEXTERN int Q_ZEXPORT inflateSync OF((z_streamp strm));
|
|
770 |
/*
|
|
771 |
Skips invalid compressed data until a full flush point (see above the
|
|
772 |
description of deflate with Z_FULL_FLUSH) can be found, or until all
|
|
773 |
available input is skipped. No output is provided.
|
|
774 |
|
|
775 |
inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
|
|
776 |
if no more input was provided, Z_DATA_ERROR if no flush point has been found,
|
|
777 |
or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
|
|
778 |
case, the application may save the current current value of total_in which
|
|
779 |
indicates where valid compressed data was found. In the error case, the
|
|
780 |
application may repeatedly call inflateSync, providing more input each time,
|
|
781 |
until success or end of the input data.
|
|
782 |
*/
|
|
783 |
|
|
784 |
ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
|
|
785 |
z_streamp source));
|
|
786 |
/*
|
|
787 |
Sets the destination stream as a complete copy of the source stream.
|
|
788 |
|
|
789 |
This function can be useful when randomly accessing a large stream. The
|
|
790 |
first pass through the stream can periodically record the inflate state,
|
|
791 |
allowing restarting inflate at those points when randomly accessing the
|
|
792 |
stream.
|
|
793 |
|
|
794 |
inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
|
|
795 |
enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
|
|
796 |
(such as zalloc being NULL). msg is left unchanged in both source and
|
|
797 |
destination.
|
|
798 |
*/
|
|
799 |
|
|
800 |
ZEXTERN int Q_ZEXPORT inflateReset OF((z_streamp strm));
|
|
801 |
/*
|
|
802 |
This function is equivalent to inflateEnd followed by inflateInit,
|
|
803 |
but does not free and reallocate all the internal decompression state.
|
|
804 |
The stream will keep attributes that may have been set by inflateInit2.
|
|
805 |
|
|
806 |
inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
|
|
807 |
stream state was inconsistent (such as zalloc or state being NULL).
|
|
808 |
*/
|
|
809 |
|
|
810 |
ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
|
|
811 |
int bits,
|
|
812 |
int value));
|
|
813 |
/*
|
|
814 |
This function inserts bits in the inflate input stream. The intent is
|
|
815 |
that this function is used to start inflating at a bit position in the
|
|
816 |
middle of a byte. The provided bits will be used before any bytes are used
|
|
817 |
from next_in. This function should only be used with raw inflate, and
|
|
818 |
should be used before the first inflate() call after inflateInit2() or
|
|
819 |
inflateReset(). bits must be less than or equal to 16, and that many of the
|
|
820 |
least significant bits of value will be inserted in the input.
|
|
821 |
|
|
822 |
inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
|
|
823 |
stream state was inconsistent.
|
|
824 |
*/
|
|
825 |
|
|
826 |
ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
|
|
827 |
gz_headerp head));
|
|
828 |
/*
|
|
829 |
inflateGetHeader() requests that gzip header information be stored in the
|
|
830 |
provided gz_header structure. inflateGetHeader() may be called after
|
|
831 |
inflateInit2() or inflateReset(), and before the first call of inflate().
|
|
832 |
As inflate() processes the gzip stream, head->done is zero until the header
|
|
833 |
is completed, at which time head->done is set to one. If a zlib stream is
|
|
834 |
being decoded, then head->done is set to -1 to indicate that there will be
|
|
835 |
no gzip header information forthcoming. Note that Z_BLOCK can be used to
|
|
836 |
force inflate() to return immediately after header processing is complete
|
|
837 |
and before any actual data is decompressed.
|
|
838 |
|
|
839 |
The text, time, xflags, and os fields are filled in with the gzip header
|
|
840 |
contents. hcrc is set to true if there is a header CRC. (The header CRC
|
|
841 |
was valid if done is set to one.) If extra is not Z_NULL, then extra_max
|
|
842 |
contains the maximum number of bytes to write to extra. Once done is true,
|
|
843 |
extra_len contains the actual extra field length, and extra contains the
|
|
844 |
extra field, or that field truncated if extra_max is less than extra_len.
|
|
845 |
If name is not Z_NULL, then up to name_max characters are written there,
|
|
846 |
terminated with a zero unless the length is greater than name_max. If
|
|
847 |
comment is not Z_NULL, then up to comm_max characters are written there,
|
|
848 |
terminated with a zero unless the length is greater than comm_max. When
|
|
849 |
any of extra, name, or comment are not Z_NULL and the respective field is
|
|
850 |
not present in the header, then that field is set to Z_NULL to signal its
|
|
851 |
absence. This allows the use of deflateSetHeader() with the returned
|
|
852 |
structure to duplicate the header. However if those fields are set to
|
|
853 |
allocated memory, then the application will need to save those pointers
|
|
854 |
elsewhere so that they can be eventually freed.
|
|
855 |
|
|
856 |
If inflateGetHeader is not used, then the header information is simply
|
|
857 |
discarded. The header is always checked for validity, including the header
|
|
858 |
CRC if present. inflateReset() will reset the process to discard the header
|
|
859 |
information. The application would need to call inflateGetHeader() again to
|
|
860 |
retrieve the header from the next gzip stream.
|
|
861 |
|
|
862 |
inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
|
|
863 |
stream state was inconsistent.
|
|
864 |
*/
|
|
865 |
|
|
866 |
/*
|
|
867 |
ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
|
|
868 |
unsigned char FAR *window));
|
|
869 |
|
|
870 |
Initialize the internal stream state for decompression using inflateBack()
|
|
871 |
calls. The fields zalloc, zfree and opaque in strm must be initialized
|
|
872 |
before the call. If zalloc and zfree are Z_NULL, then the default library-
|
|
873 |
derived memory allocation routines are used. windowBits is the base two
|
|
874 |
logarithm of the window size, in the range 8..15. window is a caller
|
|
875 |
supplied buffer of that size. Except for special applications where it is
|
|
876 |
assured that deflate was used with small window sizes, windowBits must be 15
|
|
877 |
and a 32K byte window must be supplied to be able to decompress general
|
|
878 |
deflate streams.
|
|
879 |
|
|
880 |
See inflateBack() for the usage of these routines.
|
|
881 |
|
|
882 |
inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
|
|
883 |
the paramaters are invalid, Z_MEM_ERROR if the internal state could not
|
|
884 |
be allocated, or Z_VERSION_ERROR if the version of the library does not
|
|
885 |
match the version of the header file.
|
|
886 |
*/
|
|
887 |
|
|
888 |
typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
|
|
889 |
typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
|
|
890 |
|
|
891 |
ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
|
|
892 |
in_func in, void FAR *in_desc,
|
|
893 |
out_func out, void FAR *out_desc));
|
|
894 |
/*
|
|
895 |
inflateBack() does a raw inflate with a single call using a call-back
|
|
896 |
interface for input and output. This is more efficient than inflate() for
|
|
897 |
file i/o applications in that it avoids copying between the output and the
|
|
898 |
sliding window by simply making the window itself the output buffer. This
|
|
899 |
function trusts the application to not change the output buffer passed by
|
|
900 |
the output function, at least until inflateBack() returns.
|
|
901 |
|
|
902 |
inflateBackInit() must be called first to allocate the internal state
|
|
903 |
and to initialize the state with the user-provided window buffer.
|
|
904 |
inflateBack() may then be used multiple times to inflate a complete, raw
|
|
905 |
deflate stream with each call. inflateBackEnd() is then called to free
|
|
906 |
the allocated state.
|
|
907 |
|
|
908 |
A raw deflate stream is one with no zlib or gzip header or trailer.
|
|
909 |
This routine would normally be used in a utility that reads zip or gzip
|
|
910 |
files and writes out uncompressed files. The utility would decode the
|
|
911 |
header and process the trailer on its own, hence this routine expects
|
|
912 |
only the raw deflate stream to decompress. This is different from the
|
|
913 |
normal behavior of inflate(), which expects either a zlib or gzip header and
|
|
914 |
trailer around the deflate stream.
|
|
915 |
|
|
916 |
inflateBack() uses two subroutines supplied by the caller that are then
|
|
917 |
called by inflateBack() for input and output. inflateBack() calls those
|
|
918 |
routines until it reads a complete deflate stream and writes out all of the
|
|
919 |
uncompressed data, or until it encounters an error. The function's
|
|
920 |
parameters and return types are defined above in the in_func and out_func
|
|
921 |
typedefs. inflateBack() will call in(in_desc, &buf) which should return the
|
|
922 |
number of bytes of provided input, and a pointer to that input in buf. If
|
|
923 |
there is no input available, in() must return zero--buf is ignored in that
|
|
924 |
case--and inflateBack() will return a buffer error. inflateBack() will call
|
|
925 |
out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
|
|
926 |
should return zero on success, or non-zero on failure. If out() returns
|
|
927 |
non-zero, inflateBack() will return with an error. Neither in() nor out()
|
|
928 |
are permitted to change the contents of the window provided to
|
|
929 |
inflateBackInit(), which is also the buffer that out() uses to write from.
|
|
930 |
The length written by out() will be at most the window size. Any non-zero
|
|
931 |
amount of input may be provided by in().
|
|
932 |
|
|
933 |
For convenience, inflateBack() can be provided input on the first call by
|
|
934 |
setting strm->next_in and strm->avail_in. If that input is exhausted, then
|
|
935 |
in() will be called. Therefore strm->next_in must be initialized before
|
|
936 |
calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
|
|
937 |
immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
|
|
938 |
must also be initialized, and then if strm->avail_in is not zero, input will
|
|
939 |
initially be taken from strm->next_in[0 .. strm->avail_in - 1].
|
|
940 |
|
|
941 |
The in_desc and out_desc parameters of inflateBack() is passed as the
|
|
942 |
first parameter of in() and out() respectively when they are called. These
|
|
943 |
descriptors can be optionally used to pass any information that the caller-
|
|
944 |
supplied in() and out() functions need to do their job.
|
|
945 |
|
|
946 |
On return, inflateBack() will set strm->next_in and strm->avail_in to
|
|
947 |
pass back any unused input that was provided by the last in() call. The
|
|
948 |
return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
|
|
949 |
if in() or out() returned an error, Z_DATA_ERROR if there was a format
|
|
950 |
error in the deflate stream (in which case strm->msg is set to indicate the
|
|
951 |
nature of the error), or Z_STREAM_ERROR if the stream was not properly
|
|
952 |
initialized. In the case of Z_BUF_ERROR, an input or output error can be
|
|
953 |
distinguished using strm->next_in which will be Z_NULL only if in() returned
|
|
954 |
an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
|
|
955 |
out() returning non-zero. (in() will always be called before out(), so
|
|
956 |
strm->next_in is assured to be defined if out() returns non-zero.) Note
|
|
957 |
that inflateBack() cannot return Z_OK.
|
|
958 |
*/
|
|
959 |
|
|
960 |
ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
|
|
961 |
/*
|
|
962 |
All memory allocated by inflateBackInit() is freed.
|
|
963 |
|
|
964 |
inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
|
|
965 |
state was inconsistent.
|
|
966 |
*/
|
|
967 |
|
|
968 |
ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
|
|
969 |
/* Return flags indicating compile-time options.
|
|
970 |
|
|
971 |
Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
|
|
972 |
1.0: size of uInt
|
|
973 |
3.2: size of uLong
|
|
974 |
5.4: size of voidpf (pointer)
|
|
975 |
7.6: size of z_off_t
|
|
976 |
|
|
977 |
Compiler, assembler, and debug options:
|
|
978 |
8: DEBUG
|
|
979 |
9: ASMV or ASMINF -- use ASM code
|
|
980 |
10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
|
|
981 |
11: 0 (reserved)
|
|
982 |
|
|
983 |
One-time table building (smaller code, but not thread-safe if true):
|
|
984 |
12: BUILDFIXED -- build static block decoding tables when needed
|
|
985 |
13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
|
|
986 |
14,15: 0 (reserved)
|
|
987 |
|
|
988 |
Library content (indicates missing functionality):
|
|
989 |
16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
|
|
990 |
deflate code when not needed)
|
|
991 |
17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
|
|
992 |
and decode gzip streams (to avoid linking crc code)
|
|
993 |
18-19: 0 (reserved)
|
|
994 |
|
|
995 |
Operation variations (changes in library functionality):
|
|
996 |
20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
|
|
997 |
21: FASTEST -- deflate algorithm with only one, lowest compression level
|
|
998 |
22,23: 0 (reserved)
|
|
999 |
|
|
1000 |
The sprintf variant used by gzprintf (zero is best):
|
|
1001 |
24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
|
|
1002 |
25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
|
|
1003 |
26: 0 = returns value, 1 = void -- 1 means inferred string length returned
|
|
1004 |
|
|
1005 |
Remainder:
|
|
1006 |
27-31: 0 (reserved)
|
|
1007 |
*/
|
|
1008 |
|
|
1009 |
|
|
1010 |
/* utility functions */
|
|
1011 |
|
|
1012 |
/*
|
|
1013 |
The following utility functions are implemented on top of the
|
|
1014 |
basic stream-oriented functions. To simplify the interface, some
|
|
1015 |
default options are assumed (compression level and memory usage,
|
|
1016 |
standard memory allocation functions). The source code of these
|
|
1017 |
utility functions can easily be modified if you need special options.
|
|
1018 |
*/
|
|
1019 |
|
|
1020 |
ZEXTERN int Q_ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
|
|
1021 |
const Bytef *source, uLong sourceLen));
|
|
1022 |
/*
|
|
1023 |
Compresses the source buffer into the destination buffer. sourceLen is
|
|
1024 |
the byte length of the source buffer. Upon entry, destLen is the total
|
|
1025 |
size of the destination buffer, which must be at least the value returned
|
|
1026 |
by compressBound(sourceLen). Upon exit, destLen is the actual size of the
|
|
1027 |
compressed buffer.
|
|
1028 |
This function can be used to compress a whole file at once if the
|
|
1029 |
input file is mmap'ed.
|
|
1030 |
compress returns Z_OK if success, Z_MEM_ERROR if there was not
|
|
1031 |
enough memory, Z_BUF_ERROR if there was not enough room in the output
|
|
1032 |
buffer.
|
|
1033 |
*/
|
|
1034 |
|
|
1035 |
ZEXTERN int Q_ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
|
|
1036 |
const Bytef *source, uLong sourceLen,
|
|
1037 |
int level));
|
|
1038 |
/*
|
|
1039 |
Compresses the source buffer into the destination buffer. The level
|
|
1040 |
parameter has the same meaning as in deflateInit. sourceLen is the byte
|
|
1041 |
length of the source buffer. Upon entry, destLen is the total size of the
|
|
1042 |
destination buffer, which must be at least the value returned by
|
|
1043 |
compressBound(sourceLen). Upon exit, destLen is the actual size of the
|
|
1044 |
compressed buffer.
|
|
1045 |
|
|
1046 |
compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
|
|
1047 |
memory, Z_BUF_ERROR if there was not enough room in the output buffer,
|
|
1048 |
Z_STREAM_ERROR if the level parameter is invalid.
|
|
1049 |
*/
|
|
1050 |
|
|
1051 |
ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
|
|
1052 |
/*
|
|
1053 |
compressBound() returns an upper bound on the compressed size after
|
|
1054 |
compress() or compress2() on sourceLen bytes. It would be used before
|
|
1055 |
a compress() or compress2() call to allocate the destination buffer.
|
|
1056 |
*/
|
|
1057 |
|
|
1058 |
ZEXTERN int Q_ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
|
|
1059 |
const Bytef *source, uLong sourceLen));
|
|
1060 |
/*
|
|
1061 |
Decompresses the source buffer into the destination buffer. sourceLen is
|
|
1062 |
the byte length of the source buffer. Upon entry, destLen is the total
|
|
1063 |
size of the destination buffer, which must be large enough to hold the
|
|
1064 |
entire uncompressed data. (The size of the uncompressed data must have
|
|
1065 |
been saved previously by the compressor and transmitted to the decompressor
|
|
1066 |
by some mechanism outside the scope of this compression library.)
|
|
1067 |
Upon exit, destLen is the actual size of the compressed buffer.
|
|
1068 |
This function can be used to decompress a whole file at once if the
|
|
1069 |
input file is mmap'ed.
|
|
1070 |
|
|
1071 |
uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
|
|
1072 |
enough memory, Z_BUF_ERROR if there was not enough room in the output
|
|
1073 |
buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
|
|
1074 |
*/
|
|
1075 |
|
|
1076 |
|
|
1077 |
typedef voidp gzFile;
|
|
1078 |
|
|
1079 |
ZEXTERN gzFile Q_ZEXPORT gzopen OF((const char *path, const char *mode));
|
|
1080 |
/*
|
|
1081 |
Opens a gzip (.gz) file for reading or writing. The mode parameter
|
|
1082 |
is as in fopen ("rb" or "wb") but can also include a compression level
|
|
1083 |
("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
|
|
1084 |
Huffman only compression as in "wb1h", or 'R' for run-length encoding
|
|
1085 |
as in "wb1R". (See the description of deflateInit2 for more information
|
|
1086 |
about the strategy parameter.)
|
|
1087 |
|
|
1088 |
gzopen can be used to read a file which is not in gzip format; in this
|
|
1089 |
case gzread will directly read from the file without decompression.
|
|
1090 |
|
|
1091 |
gzopen returns NULL if the file could not be opened or if there was
|
|
1092 |
insufficient memory to allocate the (de)compression state; errno
|
|
1093 |
can be checked to distinguish the two cases (if errno is zero, the
|
|
1094 |
zlib error is Z_MEM_ERROR). */
|
|
1095 |
|
|
1096 |
ZEXTERN gzFile Q_ZEXPORT gzdopen OF((int fd, const char *mode));
|
|
1097 |
/*
|
|
1098 |
gzdopen() associates a gzFile with the file descriptor fd. File
|
|
1099 |
descriptors are obtained from calls like open, dup, creat, pipe or
|
|
1100 |
fileno (in the file has been previously opened with fopen).
|
|
1101 |
The mode parameter is as in gzopen.
|
|
1102 |
The next call of gzclose on the returned gzFile will also close the
|
|
1103 |
file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
|
|
1104 |
descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
|
|
1105 |
gzdopen returns NULL if there was insufficient memory to allocate
|
|
1106 |
the (de)compression state.
|
|
1107 |
*/
|
|
1108 |
|
|
1109 |
ZEXTERN int Q_ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
|
|
1110 |
/*
|
|
1111 |
Dynamically update the compression level or strategy. See the description
|
|
1112 |
of deflateInit2 for the meaning of these parameters.
|
|
1113 |
gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
|
|
1114 |
opened for writing.
|
|
1115 |
*/
|
|
1116 |
|
|
1117 |
ZEXTERN int Q_ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
|
|
1118 |
/*
|
|
1119 |
Reads the given number of uncompressed bytes from the compressed file.
|
|
1120 |
If the input file was not in gzip format, gzread copies the given number
|
|
1121 |
of bytes into the buffer.
|
|
1122 |
gzread returns the number of uncompressed bytes actually read (0 for
|
|
1123 |
end of file, -1 for error). */
|
|
1124 |
|
|
1125 |
ZEXTERN int Q_ZEXPORT gzwrite OF((gzFile file,
|
|
1126 |
voidpc buf, unsigned len));
|
|
1127 |
/*
|
|
1128 |
Writes the given number of uncompressed bytes into the compressed file.
|
|
1129 |
gzwrite returns the number of uncompressed bytes actually written
|
|
1130 |
(0 in case of error).
|
|
1131 |
*/
|
|
1132 |
|
|
1133 |
ZEXTERN int Q_ZEXPORT gzprintf OF((gzFile file, const char *format, ...));
|
|
1134 |
/*
|
|
1135 |
Converts, formats, and writes the args to the compressed file under
|
|
1136 |
control of the format string, as in fprintf. gzprintf returns the number of
|
|
1137 |
uncompressed bytes actually written (0 in case of error). The number of
|
|
1138 |
uncompressed bytes written is limited to 4095. The caller should assure that
|
|
1139 |
this limit is not exceeded. If it is exceeded, then gzprintf() will return
|
|
1140 |
return an error (0) with nothing written. In this case, there may also be a
|
|
1141 |
buffer overflow with unpredictable consequences, which is possible only if
|
|
1142 |
zlib was compiled with the insecure functions sprintf() or vsprintf()
|
|
1143 |
because the secure snprintf() or vsnprintf() functions were not available.
|
|
1144 |
*/
|
|
1145 |
|
|
1146 |
ZEXTERN int Q_ZEXPORT gzputs OF((gzFile file, const char *s));
|
|
1147 |
/*
|
|
1148 |
Writes the given null-terminated string to the compressed file, excluding
|
|
1149 |
the terminating null character.
|
|
1150 |
gzputs returns the number of characters written, or -1 in case of error.
|
|
1151 |
*/
|
|
1152 |
|
|
1153 |
ZEXTERN Q_ZEXPORT char * gzgets OF((gzFile file, char *buf, int len));
|
|
1154 |
/*
|
|
1155 |
Reads bytes from the compressed file until len-1 characters are read, or
|
|
1156 |
a newline character is read and transferred to buf, or an end-of-file
|
|
1157 |
condition is encountered. The string is then terminated with a null
|
|
1158 |
character.
|
|
1159 |
gzgets returns buf, or Z_NULL in case of error.
|
|
1160 |
*/
|
|
1161 |
|
|
1162 |
ZEXTERN int Q_ZEXPORT gzputc OF((gzFile file, int c));
|
|
1163 |
/*
|
|
1164 |
Writes c, converted to an unsigned char, into the compressed file.
|
|
1165 |
gzputc returns the value that was written, or -1 in case of error.
|
|
1166 |
*/
|
|
1167 |
|
|
1168 |
ZEXTERN int Q_ZEXPORT gzgetc OF((gzFile file));
|
|
1169 |
/*
|
|
1170 |
Reads one byte from the compressed file. gzgetc returns this byte
|
|
1171 |
or -1 in case of end of file or error.
|
|
1172 |
*/
|
|
1173 |
|
|
1174 |
ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
|
|
1175 |
/*
|
|
1176 |
Push one character back onto the stream to be read again later.
|
|
1177 |
Only one character of push-back is allowed. gzungetc() returns the
|
|
1178 |
character pushed, or -1 on failure. gzungetc() will fail if a
|
|
1179 |
character has been pushed but not read yet, or if c is -1. The pushed
|
|
1180 |
character will be discarded if the stream is repositioned with gzseek()
|
|
1181 |
or gzrewind().
|
|
1182 |
*/
|
|
1183 |
|
|
1184 |
ZEXTERN int Q_ZEXPORT gzflush OF((gzFile file, int flush));
|
|
1185 |
/*
|
|
1186 |
Flushes all pending output into the compressed file. The parameter
|
|
1187 |
flush is as in the deflate() function. The return value is the zlib
|
|
1188 |
error number (see function gzerror below). gzflush returns Z_OK if
|
|
1189 |
the flush parameter is Z_FINISH and all output could be flushed.
|
|
1190 |
gzflush should be called only when strictly necessary because it can
|
|
1191 |
degrade compression.
|
|
1192 |
*/
|
|
1193 |
|
|
1194 |
ZEXTERN z_off_t Q_ZEXPORT gzseek OF((gzFile file,
|
|
1195 |
z_off_t offset, int whence));
|
|
1196 |
/*
|
|
1197 |
Sets the starting position for the next gzread or gzwrite on the
|
|
1198 |
given compressed file. The offset represents a number of bytes in the
|
|
1199 |
uncompressed data stream. The whence parameter is defined as in lseek(2);
|
|
1200 |
the value SEEK_END is not supported.
|
|
1201 |
If the file is opened for reading, this function is emulated but can be
|
|
1202 |
extremely slow. If the file is opened for writing, only forward seeks are
|
|
1203 |
supported; gzseek then compresses a sequence of zeroes up to the new
|
|
1204 |
starting position.
|
|
1205 |
|
|
1206 |
gzseek returns the resulting offset location as measured in bytes from
|
|
1207 |
the beginning of the uncompressed stream, or -1 in case of error, in
|
|
1208 |
particular if the file is opened for writing and the new starting position
|
|
1209 |
would be before the current position.
|
|
1210 |
*/
|
|
1211 |
|
|
1212 |
ZEXTERN int Q_ZEXPORT gzrewind OF((gzFile file));
|
|
1213 |
/*
|
|
1214 |
Rewinds the given file. This function is supported only for reading.
|
|
1215 |
|
|
1216 |
gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
|
|
1217 |
*/
|
|
1218 |
|
|
1219 |
ZEXTERN z_off_t Q_ZEXPORT gztell OF((gzFile file));
|
|
1220 |
/*
|
|
1221 |
Returns the starting position for the next gzread or gzwrite on the
|
|
1222 |
given compressed file. This position represents a number of bytes in the
|
|
1223 |
uncompressed data stream.
|
|
1224 |
|
|
1225 |
gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
|
|
1226 |
*/
|
|
1227 |
|
|
1228 |
ZEXTERN int Q_ZEXPORT gzeof OF((gzFile file));
|
|
1229 |
/*
|
|
1230 |
Returns 1 when EOF has previously been detected reading the given
|
|
1231 |
input stream, otherwise zero.
|
|
1232 |
*/
|
|
1233 |
|
|
1234 |
ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
|
|
1235 |
/*
|
|
1236 |
Returns 1 if file is being read directly without decompression, otherwise
|
|
1237 |
zero.
|
|
1238 |
*/
|
|
1239 |
|
|
1240 |
ZEXTERN int Q_ZEXPORT gzclose OF((gzFile file));
|
|
1241 |
/*
|
|
1242 |
Flushes all pending output if necessary, closes the compressed file
|
|
1243 |
and deallocates all the (de)compression state. The return value is the zlib
|
|
1244 |
error number (see function gzerror below).
|
|
1245 |
*/
|
|
1246 |
|
|
1247 |
ZEXTERN Q_ZEXPORT const char * gzerror OF((gzFile file, int *errnum));
|
|
1248 |
/*
|
|
1249 |
Returns the error message for the last error which occurred on the
|
|
1250 |
given compressed file. errnum is set to zlib error number. If an
|
|
1251 |
error occurred in the file system and not in the compression library,
|
|
1252 |
errnum is set to Z_ERRNO and the application may consult errno
|
|
1253 |
to get the exact error code.
|
|
1254 |
*/
|
|
1255 |
|
|
1256 |
ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
|
|
1257 |
/*
|
|
1258 |
Clears the error and end-of-file flags for file. This is analogous to the
|
|
1259 |
clearerr() function in stdio. This is useful for continuing to read a gzip
|
|
1260 |
file that is being written concurrently.
|
|
1261 |
*/
|
|
1262 |
|
|
1263 |
/* checksum functions */
|
|
1264 |
|
|
1265 |
/*
|
|
1266 |
These functions are not related to compression but are exported
|
|
1267 |
anyway because they might be useful in applications using the
|
|
1268 |
compression library.
|
|
1269 |
*/
|
|
1270 |
|
|
1271 |
ZEXTERN uLong Q_ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
|
|
1272 |
/*
|
|
1273 |
Update a running Adler-32 checksum with the bytes buf[0..len-1] and
|
|
1274 |
return the updated checksum. If buf is NULL, this function returns
|
|
1275 |
the required initial value for the checksum.
|
|
1276 |
An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
|
|
1277 |
much faster. Usage example:
|
|
1278 |
|
|
1279 |
uLong adler = adler32(0L, Z_NULL, 0);
|
|
1280 |
|
|
1281 |
while (read_buffer(buffer, length) != EOF) {
|
|
1282 |
adler = adler32(adler, buffer, length);
|
|
1283 |
}
|
|
1284 |
if (adler != original_adler) error();
|
|
1285 |
*/
|
|
1286 |
|
|
1287 |
ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
|
|
1288 |
z_off_t len2));
|
|
1289 |
/*
|
|
1290 |
Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
|
|
1291 |
and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
|
|
1292 |
each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
|
|
1293 |
seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
|
|
1294 |
*/
|
|
1295 |
|
|
1296 |
ZEXTERN uLong Q_ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
|
|
1297 |
/*
|
|
1298 |
Update a running CRC-32 with the bytes buf[0..len-1] and return the
|
|
1299 |
updated CRC-32. If buf is NULL, this function returns the required initial
|
|
1300 |
value for the for the crc. Pre- and post-conditioning (one's complement) is
|
|
1301 |
performed within this function so it shouldn't be done by the application.
|
|
1302 |
Usage example:
|
|
1303 |
|
|
1304 |
uLong crc = crc32(0L, Z_NULL, 0);
|
|
1305 |
|
|
1306 |
while (read_buffer(buffer, length) != EOF) {
|
|
1307 |
crc = crc32(crc, buffer, length);
|
|
1308 |
}
|
|
1309 |
if (crc != original_crc) error();
|
|
1310 |
*/
|
|
1311 |
|
|
1312 |
ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
|
|
1313 |
|
|
1314 |
/*
|
|
1315 |
Combine two CRC-32 check values into one. For two sequences of bytes,
|
|
1316 |
seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
|
|
1317 |
calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
|
|
1318 |
check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
|
|
1319 |
len2.
|
|
1320 |
*/
|
|
1321 |
|
|
1322 |
|
|
1323 |
/* various hacks, don't look :) */
|
|
1324 |
|
|
1325 |
/* deflateInit and inflateInit are macros to allow checking the zlib version
|
|
1326 |
* and the compiler's view of z_stream:
|
|
1327 |
*/
|
|
1328 |
ZEXTERN int Q_ZEXPORT deflateInit_ OF((z_streamp strm, int level,
|
|
1329 |
const char *version, int stream_size));
|
|
1330 |
ZEXTERN int Q_ZEXPORT inflateInit_ OF((z_streamp strm,
|
|
1331 |
const char *version, int stream_size));
|
|
1332 |
ZEXTERN int Q_ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
|
|
1333 |
int windowBits, int memLevel,
|
|
1334 |
int strategy, const char *version,
|
|
1335 |
int stream_size));
|
|
1336 |
ZEXTERN int Q_ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
|
|
1337 |
const char *version, int stream_size));
|
|
1338 |
ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
|
|
1339 |
unsigned char FAR *window,
|
|
1340 |
const char *version,
|
|
1341 |
int stream_size));
|
|
1342 |
#define deflateInit(strm, level) \
|
|
1343 |
deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
|
|
1344 |
#define inflateInit(strm) \
|
|
1345 |
inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
|
|
1346 |
#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
|
|
1347 |
deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
|
|
1348 |
(strategy), ZLIB_VERSION, sizeof(z_stream))
|
|
1349 |
#define inflateInit2(strm, windowBits) \
|
|
1350 |
inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
|
|
1351 |
#define inflateBackInit(strm, windowBits, window) \
|
|
1352 |
inflateBackInit_((strm), (windowBits), (window), \
|
|
1353 |
ZLIB_VERSION, sizeof(z_stream))
|
|
1354 |
|
|
1355 |
|
|
1356 |
#if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
|
|
1357 |
struct internal_state {int dummy;}; /* hack for buggy compilers */
|
|
1358 |
#endif
|
|
1359 |
|
|
1360 |
ZEXTERN Q_ZEXPORT const char * zError OF((int));
|
|
1361 |
ZEXTERN int Q_ZEXPORT inflateSyncPoint OF((z_streamp z));
|
|
1362 |
ZEXTERN Q_ZEXPORT const uLongf * get_crc_table OF((void));
|
|
1363 |
|
|
1364 |
#ifdef __cplusplus
|
|
1365 |
}
|
|
1366 |
#endif
|
|
1367 |
|
|
1368 |
#endif /* ZLIB_H */
|