annotate zlib/zlib.h @ 3:5a977ccbc7a9 default tip

Empty changelog
author darius
date Sat, 06 Dec 1997 05:41:29 +0000
parents
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
3
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
1 /* zlib.h -- interface of the 'zlib' general purpose compression library
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
2 version 0.92 May 3rd, 1995.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
3
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
4 Copyright (C) 1995 Jean-loup Gailly and Mark Adler
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
5
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
6 This software is provided 'as-is', without any express or implied
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
7 warranty. In no event will the authors be held liable for any damages
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
8 arising from the use of this software.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
9
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
10 Permission is granted to anyone to use this software for any purpose,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
11 including commercial applications, and to alter it and redistribute it
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
12 freely, subject to the following restrictions:
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
13
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
14 1. The origin of this software must not be misrepresented; you must not
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
15 claim that you wrote the original software. If you use this software
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
16 in a product, an acknowledgment in the product documentation would be
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
17 appreciated but is not required.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
18 2. Altered source versions must be plainly marked as such, and must not be
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
19 misrepresented as being the original software.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
20 3. This notice may not be removed or altered from any source distribution.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
21
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
22 Jean-loup Gailly Mark Adler
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
23 gzip@prep.ai.mit.edu madler@cco.caltech.edu
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
24 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
25
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
26 #ifndef _ZLIB_H
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
27 #define _ZLIB_H
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
28
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
29 #include "zconf.h"
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
30
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
31 #define ZLIB_VERSION "0.92"
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
32
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
33 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
34 The 'zlib' compression library provides in-memory compression and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
35 decompression functions, including integrity checks of the uncompressed
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
36 data. This version of the library supports only one compression method
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
37 (deflation) but other algorithms may be added later and will have the same
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
38 stream interface.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
39
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
40 For compression the application must provide the output buffer and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
41 may optionally provide the input buffer for optimization. For decompression,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
42 the application must provide the input buffer and may optionally provide
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
43 the output buffer for optimization.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
44
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
45 Compression can be done in a single step if the buffers are large
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
46 enough (for example if an input file is mmap'ed), or can be done by
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
47 repeated calls of the compression function. In the latter case, the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
48 application must provide more input and/or consume the output
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
49 (providing more output space) before each call.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
50 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
51
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
52 typedef voidp (*alloc_func) __P((voidp opaque, uInt items, uInt size));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
53 typedef void (*free_func) __P((voidp opaque, voidp address));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
54
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
55 struct internal_state;
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
56
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
57 typedef struct z_stream_s {
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
58 Byte *next_in; /* next input byte */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
59 uInt avail_in; /* number of bytes available at next_in */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
60 uLong total_in; /* total nb of input bytes read so far */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
61
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
62 Byte *next_out; /* next output byte should be put there */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
63 uInt avail_out; /* remaining free space at next_out */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
64 uLong total_out; /* total nb of bytes output so far */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
65
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
66 char *msg; /* last error message, NULL if no error */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
67 struct internal_state *state; /* not visible by applications */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
68
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
69 alloc_func zalloc; /* used to allocate the internal state */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
70 free_func zfree; /* used to free the internal state */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
71 voidp opaque; /* private data object passed to zalloc and zfree */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
72
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
73 Byte data_type; /* best guess about the data type: ascii or binary */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
74
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
75 } z_stream;
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
76
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
77 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
78 The application must update next_in and avail_in when avail_in has
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
79 dropped to zero. It must update next_out and avail_out when avail_out
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
80 has dropped to zero. The application must initialize zalloc, zfree and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
81 opaque before calling the init function. All other fields are set by the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
82 compression library and must not be updated by the application.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
83
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
84 The opaque value provided by the application will be passed as the first
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
85 parameter for calls of zalloc and zfree. This can be useful for custom
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
86 memory management. The compression library attaches no meaning to the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
87 opaque value.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
88
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
89 zalloc must return Z_NULL if there is not enough memory for the object.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
90 On 16-bit systems, the functions zalloc and zfree must be able to allocate
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
91 exactly 65536 bytes, but will not be required to allocate more than this
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
92 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
93 pointers returned by zalloc for objects of exactly 65536 bytes *must*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
94 have their offset normalized to zero. The default allocation function
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
95 provided by this library ensures this (see zutil.c). To reduce memory
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
96 requirements and avoid any allocation of 64K objects, at the expense of
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
97 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
98
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
99 The fields total_in and total_out can be used for statistics or
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
100 progress reports. After compression, total_in holds the total size of
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
101 the uncompressed data and may be saved for use in the decompressor
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
102 (particularly if the decompressor wants to decompress everything in
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
103 a single step).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
104 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
105
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
106 /* constants */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
107
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
108 #define Z_NO_FLUSH 0
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
109 #define Z_PARTIAL_FLUSH 1
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
110 #define Z_FULL_FLUSH 2
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
111 #define Z_FINISH 4
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
112 /* See deflate() below for the usage of these constants */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
113
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
114 #define Z_OK 0
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
115 #define Z_STREAM_END 1
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
116 #define Z_ERRNO (-1)
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
117 #define Z_STREAM_ERROR (-2)
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
118 #define Z_DATA_ERROR (-3)
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
119 #define Z_MEM_ERROR (-4)
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
120 #define Z_BUF_ERROR (-5)
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
121 /* error codes for the compression/decompression functions */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
122
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
123 #define Z_BEST_SPEED 1
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
124 #define Z_BEST_COMPRESSION 9
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
125 #define Z_DEFAULT_COMPRESSION (-1)
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
126 /* compression levels */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
127
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
128 #define Z_FILTERED 1
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
129 #define Z_HUFFMAN_ONLY 2
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
130 #define Z_DEFAULT_STRATEGY 0
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
131
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
132 #define Z_BINARY 0
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
133 #define Z_ASCII 1
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
134 #define Z_UNKNOWN 2
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
135 /* Used to set the data_type field */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
136
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
137 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
138
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
139 extern char *zlib_version;
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
140 /* The application can compare zlib_version and ZLIB_VERSION for consistency.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
141 If the first character differs, the library code actually used is
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
142 not compatible with the zlib.h header file used by the application.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
143 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
144
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
145 /* basic functions */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
146
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
147 extern int deflateInit __P((z_stream *strm, int level));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
148 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
149 Initializes the internal stream state for compression. The fields
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
150 zalloc, zfree and opaque must be initialized before by the caller.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
151 If zalloc and zfree are set to Z_NULL, deflateInit updates them to
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
152 use default allocation functions.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
153
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
154 The compression level must be Z_DEFAULT_COMPRESSION, or between 1 and 9:
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
155 1 gives best speed, 9 gives best compression. Z_DEFAULT_COMPRESSION requests
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
156 a default compromise between speed and compression (currently equivalent
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
157 to level 6).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
158
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
159 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
160 enough memory, Z_STREAM_ERROR if level is not a valid compression level.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
161 msg is set to null if there is no error message. deflateInit does not
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
162 perform any compression: this will be done by deflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
163 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
164
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
165
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
166 extern int deflate __P((z_stream *strm, int flush));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
167 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
168 Performs one or both of the following actions:
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
169
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
170 - Compress more input starting at next_in and update next_in and avail_in
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
171 accordingly. If not all input can be processed (because there is not
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
172 enough room in the output buffer), next_in and avail_in are updated and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
173 processing will resume at this point for the next call of deflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
174
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
175 - Provide more output starting at next_out and update next_out and avail_out
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
176 accordingly. This action is forced if the parameter flush is non zero.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
177 Forcing flush frequently degrades the compression ratio, so this parameter
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
178 should be set only when necessary (in interactive applications).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
179 Some output may be provided even if flush is not set.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
180
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
181 Before the call of deflate(), the application should ensure that at least
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
182 one of the actions is possible, by providing more input and/or consuming
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
183 more output, and updating avail_in or avail_out accordingly; avail_out
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
184 should never be zero before the call. The application can consume the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
185 compressed output when it wants, for example when the output buffer is full
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
186 (avail_out == 0), or after each call of deflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
187
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
188 If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
189 block is terminated and flushed to the output buffer so that the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
190 decompressor can get all input data available so far. For method 9, a future
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
191 variant on method 8, the current block will be flushed but not terminated.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
192 If flush is set to Z_FULL_FLUSH, the compression block is terminated, a
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
193 special marker is output and the compression dictionary is discarded; this
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
194 is useful to allow the decompressor to synchronize if one compressed block
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
195 has been damaged (see inflateSync below). Flushing degrades compression and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
196 so should be used only when necessary. Using Z_FULL_FLUSH too often can
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
197 seriously degrade the compression.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
198
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
199 If the parameter flush is set to Z_FINISH, all pending input is processed,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
200 all pending output is flushed and deflate returns with Z_STREAM_END if there
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
201 was enough output space; if deflate returns with Z_OK, this function must be
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
202 called again with Z_FINISH and more output space (updated avail_out) but no
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
203 more input data, until it returns with Z_STREAM_END or an error. After
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
204 deflate has returned Z_STREAM_END, the only possible operations on the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
205 stream are deflateReset or deflateEnd.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
206
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
207 Z_FINISH can be used immediately after deflateInit if all the compression
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
208 is to be done in a single step. In this case, avail_out must be at least
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
209 0.1% larger than avail_in plus 12 bytes. If deflate does not return
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
210 Z_STREAM_END, then it must be called again as described above.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
211
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
212 deflate() may update data_type if it can make a good guess about
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
213 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
214 binary. This field is only for information purposes and does not affect
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
215 the compression algorithm in any manner.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
216
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
217 deflate() returns Z_OK if some progress has been made (more input
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
218 processed or more output produced), Z_STREAM_END if all input has been
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
219 consumed and all output has been produced (only when flush is set to
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
220 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
221 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
222 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
223
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
224
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
225 extern int deflateEnd __P((z_stream *strm));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
226 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
227 All dynamically allocated data structures for this stream are freed.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
228 This function discards any unprocessed input and does not flush any
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
229 pending output.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
230
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
231 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
232 stream state was inconsistent. In the error case, msg may be set
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
233 but then points to a static string (which must not be deallocated).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
234 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
235
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
236
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
237 extern int inflateInit __P((z_stream *strm));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
238 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
239 Initializes the internal stream state for decompression. The fields
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
240 zalloc and zfree must be initialized before by the caller. If zalloc and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
241 zfree are set to Z_NULL, deflateInit updates them to use default allocation
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
242 functions.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
243
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
244 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
245 enough memory. msg is set to null if there is no error message.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
246 inflateInit does not perform any decompression: this will be done by
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
247 inflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
248 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
249
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
250
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
251 extern int inflate __P((z_stream *strm, int flush));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
252 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
253 Performs one or both of the following actions:
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
254
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
255 - Decompress more input starting at next_in and update next_in and avail_in
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
256 accordingly. If not all input can be processed (because there is not
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
257 enough room in the output buffer), next_in is updated and processing
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
258 will resume at this point for the next call of inflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
259
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
260 - Provide more output starting at next_out and update next_out and avail_out
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
261 accordingly. inflate() always provides as much output as possible
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
262 (until no more input data or no more space in the output buffer).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
263
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
264 Before the call of inflate(), the application should ensure that at least
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
265 one of the actions is possible, by providing more input and/or consuming
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
266 more output, and updating the next_* and avail_* values accordingly.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
267 The application can consume the uncompressed output when it wants, for
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
268 example when the output buffer is full (avail_out == 0), or after each
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
269 call of inflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
270
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
271 If the parameter flush is set to Z_PARTIAL_FLUSH, inflate flushes as much
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
272 output as possible to the output buffer. The flushing behavior of inflate is
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
273 not specified for values of the flush parameter other than Z_PARTIAL_FLUSH
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
274 and Z_FINISH, but the current implementation actually flushes as much output
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
275 as possible anyway.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
276
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
277 inflate() should normally be called until it returns Z_STREAM_END or an
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
278 error. However if all decompression is to be performed in a single step
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
279 (a single call of inflate), the parameter flush should be set to
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
280 Z_FINISH. In this case all pending input is processed and all pending
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
281 output is flushed; avail_out must be large enough to hold all the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
282 uncompressed data. (The size of the uncompressed data may have been saved
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
283 by the compressor for this purpose.) The next operation on this stream must
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
284 be inflateEnd to deallocate the decompression state.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
285
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
286 inflate() returns Z_OK if some progress has been made (more input
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
287 processed or more output produced), Z_STREAM_END if the end of the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
288 compressed data has been reached and all uncompressed output has been
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
289 produced, Z_DATA_ERROR if the input data was corrupted, Z_STREAM_ERROR if
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
290 the stream structure was inconsistent (for example if next_in or next_out
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
291 was NULL), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if no
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
292 progress is possible or if there was not enough room in the output buffer
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
293 when Z_FINISH is used. In the Z_DATA_ERROR case, the application may then
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
294 call inflateSync to look for a good compression block.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
295 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
296
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
297
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
298 extern int inflateEnd __P((z_stream *strm));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
299 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
300 All dynamically allocated data structures for this stream are freed.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
301 This function discards any unprocessed input and does not flush any
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
302 pending output.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
303
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
304 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
305 was inconsistent. In the error case, msg may be set but then points to a
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
306 static string (which must not be deallocated).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
307 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
308
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
309 /* advanced functions */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
310
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
311 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
312 The following functions are needed only in some special applications.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
313 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
314
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
315 extern int deflateInit2 __P((z_stream *strm,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
316 int level,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
317 int method,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
318 int windowBits,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
319 int memLevel,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
320 int strategy));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
321 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
322 This is another version of deflateInit with more compression options. The
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
323 fields next_in, zalloc and zfree must be initialized before by the caller.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
324
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
325 The method parameter is the compression method. It must be 8 in this
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
326 version of the library. (Method 9 will allow a 64K history buffer and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
327 partial block flushes.)
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
328
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
329 The windowBits parameter is the base two logarithm of the window size
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
330 (the size of the history buffer). It should be in the range 8..15 for this
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
331 version of the library (the value 16 will be allowed for method 9). Larger
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
332 values of this parameter result in better compression at the expense of
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
333 memory usage. The default value is 15 if deflateInit is used instead.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
334
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
335 The memLevel parameter specifies how much memory should be allocated
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
336 for the internal compression state. memLevel=1 uses minimum memory but
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
337 is slow and reduces compression ratio; memLevel=9 uses maximum memory
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
338 for optimal speed. The default value is 8. See zconf.h for total memory
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
339 usage as a function of windowBits and memLevel.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
340
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
341 The strategy parameter is used to tune the compression algorithm. Use
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
342 the value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
343 produced by a filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
344 encoding only (no string match). Filtered data consists mostly of small
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
345 values with a somewhat random distribution. In this case, the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
346 compression algorithm is tuned to compress them better. The strategy
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
347 parameter only affects the compression ratio but not the correctness of
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
348 the compressed output even if it is not set appropriately.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
349
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
350 If next_in is not null, the library will use this buffer to hold also
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
351 some history information; the buffer must either hold the entire input
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
352 data, or have at least 1<<(windowBits+1) bytes and be writable. If next_in
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
353 is null, the library will allocate its own history buffer (and leave next_in
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
354 null). next_out need not be provided here but must be provided by the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
355 application for the next call of deflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
356
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
357 If the history buffer is provided by the application, next_in must
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
358 must never be changed by the application since the compressor maintains
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
359 information inside this buffer from call to call; the application
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
360 must provide more input only by increasing avail_in. next_in is always
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
361 reset by the library in this case.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
362
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
363 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
364 not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
365 an invalid method). msg is set to null if there is no error message.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
366 deflateInit2 does not perform any compression: this will be done by
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
367 deflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
368 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
369
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
370 extern int deflateCopy __P((z_stream *dest,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
371 z_stream *source));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
372 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
373 Sets the destination stream as a complete copy of the source stream. If
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
374 the source stream is using an application-supplied history buffer, a new
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
375 buffer is allocated for the destination stream. The compressed output
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
376 buffer is always application-supplied. It's the responsibility of the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
377 application to provide the correct values of next_out and avail_out for the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
378 next call of deflate.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
379
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
380 This function is useful when several compression strategies will be
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
381 tried, for example when there are several ways of pre-processing the input
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
382 data with a filter. The streams that will be discarded should then be freed
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
383 by calling deflateEnd. Note that deflateCopy duplicates the internal
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
384 compression state which can be quite large, so this strategy is slow and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
385 can consume lots of memory.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
386
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
387 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
388 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
389 (such as zalloc being NULL). msg is left unchanged in both source and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
390 destination.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
391 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
392
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
393 extern int deflateReset __P((z_stream *strm));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
394 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
395 This function is equivalent to deflateEnd followed by deflateInit,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
396 but does not free and reallocate all the internal compression state.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
397 The stream will keep the same compression level and any other attributes
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
398 that may have been set by deflateInit2.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
399
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
400 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
401 stream state was inconsistent (such as zalloc or state being NULL).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
402 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
403
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
404 extern int inflateInit2 __P((z_stream *strm,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
405 int windowBits));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
406 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
407 This is another version of inflateInit with more compression options. The
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
408 fields next_out, zalloc and zfree must be initialized before by the caller.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
409
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
410 The windowBits parameter is the base two logarithm of the maximum window
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
411 size (the size of the history buffer). It should be in the range 8..15 for
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
412 this version of the library (the value 16 will be allowed soon). The
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
413 default value is 15 if inflateInit is used instead. If a compressed stream
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
414 with a larger window size is given as input, inflate() will return with
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
415 the error code Z_DATA_ERROR instead of trying to allocate a larger window.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
416
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
417 If next_out is not null, the library will use this buffer for the history
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
418 buffer; the buffer must either be large enough to hold the entire output
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
419 data, or have at least 1<<windowBits bytes. If next_out is null, the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
420 library will allocate its own buffer (and leave next_out null). next_in
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
421 need not be provided here but must be provided by the application for the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
422 next call of inflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
423
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
424 If the history buffer is provided by the application, next_out must
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
425 never be changed by the application since the decompressor maintains
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
426 history information inside this buffer from call to call; the application
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
427 can only reset next_out to the beginning of the history buffer when
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
428 avail_out is zero and all output has been consumed.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
429
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
430 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
431 not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
432 windowBits < 8). msg is set to null if there is no error message.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
433 inflateInit2 does not perform any compression: this will be done by
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
434 inflate().
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
435 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
436
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
437 extern int inflateSync __P((z_stream *strm));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
438 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
439 Skips invalid compressed data until the special marker (see deflate()
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
440 above) can be found, or until all available input is skipped. No output
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
441 is provided.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
442
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
443 inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
444 if no more input was provided, Z_DATA_ERROR if no marker has been found,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
445 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
446 case, the application may save the current current value of total_in which
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
447 indicates where valid compressed data was found. In the error case, the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
448 application may repeatedly call inflateSync, providing more input each time,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
449 until success or end of the input data.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
450 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
451
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
452 extern int inflateReset __P((z_stream *strm));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
453 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
454 This function is equivalent to inflateEnd followed by inflateInit,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
455 but does not free and reallocate all the internal decompression state.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
456 The stream will keep attributes that may have been set by inflateInit2.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
457
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
458 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
459 stream state was inconsistent (such as zalloc or state being NULL).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
460 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
461
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
462
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
463 /* utility functions */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
464
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
465 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
466 The following utility functions are implemented on top of the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
467 basic stream-oriented functions. To simplify the interface, some
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
468 default options are assumed (compression level, window size,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
469 standard memory allocation functions). The source code of these
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
470 utility functions can easily be modified if you need special options.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
471 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
472
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
473 extern int compress __P((Byte *dest, uLong *destLen,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
474 Byte *source, uLong sourceLen));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
475 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
476 Compresses the source buffer into the destination buffer. sourceLen is
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
477 the byte length of the source buffer. Upon entry, destLen is the total
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
478 size of the destination buffer, which must be at least 0.1% larger than
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
479 sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
480 compressed buffer.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
481 This function can be used to compress a whole file at once if the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
482 input file is mmap'ed.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
483 compress returns Z_OK if success, Z_MEM_ERROR if there was not
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
484 enough memory, Z_BUF_ERROR if there was not enough room in the output
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
485 buffer.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
486 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
487
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
488 extern int uncompress __P((Byte *dest, uLong *destLen,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
489 Byte *source, uLong sourceLen));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
490 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
491 Decompresses the source buffer into the destination buffer. sourceLen is
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
492 the byte length of the source buffer. Upon entry, destLen is the total
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
493 size of the destination buffer, which must be large enough to hold the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
494 entire uncompressed data. (The size of the uncompressed data must have
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
495 been saved previously by the compressor and transmitted to the decompressor
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
496 by some mechanism outside the scope of this compression library.)
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
497 Upon exit, destLen is the actual size of the compressed buffer.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
498 This function can be used to decompress a whole file at once if the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
499 input file is mmap'ed.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
500
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
501 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
502 enough memory, Z_BUF_ERROR if there was not enough room in the output
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
503 buffer, or Z_DATA_ERROR if the input data was corrupted.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
504 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
505
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
506
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
507 typedef voidp gzFile;
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
508
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
509 extern gzFile gzopen __P((char *path, char *mode));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
510 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
511 Opens a gzip (.gz) file for reading or writing. The mode parameter
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
512 is as in fopen ("rb" or "wb"). gzopen can also be used to read a file
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
513 which is not in gzip format; in this case gzread will directly read from
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
514 the file without decompression.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
515 gzopen returns NULL if the file could not be opened or if there was
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
516 insufficient memory to allocate the (de)compression state; errno
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
517 can be checked to distinguish the two cases (if errno is zero, the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
518 zlib error is Z_MEM_ERROR).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
519 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
520
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
521 extern gzFile gzdopen __P((int fd, char *mode));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
522 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
523 gzdopen() associates a gzFile with the file descriptor fd. File
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
524 descriptors are obtained from calls like open, dup, creat, or pipe.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
525 The mode parameter is as in fopen ("rb" or "wb").
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
526 gzdopen returns NULL if there was insufficient memory to allocate
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
527 the (de)compression state.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
528 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
529
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
530 extern int gzread __P((gzFile file, voidp buf, unsigned len));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
531 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
532 Reads the given number of uncompressed bytes from the compressed file.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
533 If the input file was not in gzip format, gzread copies the given number
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
534 of bytes into the buffer.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
535 gzread returns the number of uncompressed bytes actually read (0 for
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
536 end of file, -1 for error). */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
537
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
538 extern int gzwrite __P((gzFile file, voidp buf, unsigned len));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
539 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
540 Writes the given number of uncompressed bytes into the compressed file.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
541 gzwrite returns the number of uncompressed bytes actually written
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
542 (0 in case of error).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
543 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
544
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
545 extern int gzflush __P((gzFile file, int flush));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
546 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
547 Flushes all pending output into the compressed file. The parameter
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
548 flush is as in the deflate() function. The return value is the zlib
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
549 error number (see function gzerror below). gzflush returns Z_OK if
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
550 the flush parameter is Z_FINISH and all output could be flushed.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
551 gzflush should be called only when strictly necessary because it can
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
552 degrade compression.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
553 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
554
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
555 extern int gzclose __P((gzFile file));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
556 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
557 Flushes all pending output if necessary, closes the compressed file
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
558 and deallocates all the (de)compression state. The return value is the zlib
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
559 error number (see function gzerror below).
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
560 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
561
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
562 extern char* gzerror __P((gzFile file, int *errnum));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
563 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
564 Returns the error message for the last error which occurred on the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
565 given compressed file. errnum is set to zlib error number. If an
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
566 error occurred in the file system and not in the compression library,
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
567 errnum is set to Z_ERRNO and the application may consult errno
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
568 to get the exact error code.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
569 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
570
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
571 /* checksum functions */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
572
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
573 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
574 These functions are not related to compression but are exported
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
575 anyway because they might be useful in applications using the
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
576 compression library.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
577 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
578
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
579 extern uLong adler32 __P((uLong adler, Byte *buf, uInt len));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
580 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
581 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
582 return the updated checksum. If buf is NULL, this function returns
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
583 the required initial value for the checksum.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
584 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
585 much faster. Usage example:
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
586
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
587 uLong adler = adler32(0L, Z_NULL, 0);
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
588
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
589 while (read_buffer(buffer, length) != EOF) {
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
590 adler = adler32(adler, buffer, length);
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
591 }
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
592 if (adler != original_adler) error();
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
593 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
594
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
595 extern uLong crc32 __P((uLong crc, Byte *buf, uInt len));
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
596 /*
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
597 Update a running crc with the bytes buf[0..len-1] and return the updated
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
598 crc. If buf is NULL, this function returns the required initial value
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
599 for the crc. Pre- and post-conditioning (one's complement) is performed
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
600 within this function so it shouldn't be done by the application.
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
601 Usage example:
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
602
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
603 uLong crc = crc32(0L, Z_NULL, 0);
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
604
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
605 while (read_buffer(buffer, length) != EOF) {
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
606 crc = crc32(crc, buffer, length);
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
607 }
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
608 if (crc != original_crc) error();
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
609 */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
610
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
611 #ifndef _Z_UTIL_H
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
612 struct internal_state {int dummy;}; /* hack for buggy compilers */
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
613 #endif
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
614
5a977ccbc7a9 Empty changelog
darius
parents:
diff changeset
615 #endif /* _ZLIB_H */