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1 /* zlib.h -- interface of the 'zlib' general p 1 /* zlib.h -- interface of the 'zlib' general purpose compression library
2 version 1.2.13, October 13th, 2022 << 2 version 1.2.11, January 15th, 2017
3 3
4 Copyright (C) 1995-2022 Jean-loup Gailly and << 4 Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
5 5
6 This software is provided 'as-is', without a 6 This software is provided 'as-is', without any express or implied
7 warranty. In no event will the authors be h 7 warranty. In no event will the authors be held liable for any damages
8 arising from the use of this software. 8 arising from the use of this software.
9 9
10 Permission is granted to anyone to use this 10 Permission is granted to anyone to use this software for any purpose,
11 including commercial applications, and to al 11 including commercial applications, and to alter it and redistribute it
12 freely, subject to the following restriction 12 freely, subject to the following restrictions:
13 13
14 1. The origin of this software must not be m 14 1. The origin of this software must not be misrepresented; you must not
15 claim that you wrote the original softwar 15 claim that you wrote the original software. If you use this software
16 in a product, an acknowledgment in the pr 16 in a product, an acknowledgment in the product documentation would be
17 appreciated but is not required. 17 appreciated but is not required.
18 2. Altered source versions must be plainly m 18 2. Altered source versions must be plainly marked as such, and must not be
19 misrepresented as being the original soft 19 misrepresented as being the original software.
20 3. This notice may not be removed or altered 20 3. This notice may not be removed or altered from any source distribution.
21 21
22 Jean-loup Gailly Mark Adler 22 Jean-loup Gailly Mark Adler
23 jloup@gzip.org madler@alumni.caltec 23 jloup@gzip.org madler@alumni.caltech.edu
24 24
25 25
26 The data format used by the zlib library is 26 The data format used by the zlib library is described by RFCs (Request for
27 Comments) 1950 to 1952 in the files http://t 27 Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
28 (zlib format), rfc1951 (deflate format) and 28 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
29 */ 29 */
30 30
31 #ifndef ZLIB_H 31 #ifndef ZLIB_H
32 #define ZLIB_H 32 #define ZLIB_H
33 33
34 #include "zconf.h" 34 #include "zconf.h"
35 35
36 #ifdef __cplusplus 36 #ifdef __cplusplus
37 extern "C" { 37 extern "C" {
38 #endif 38 #endif
39 39
40 #define ZLIB_VERSION "1.2.13" << 40 #define ZLIB_VERSION "1.2.11"
41 #define ZLIB_VERNUM 0x12d0 << 41 #define ZLIB_VERNUM 0x12b0
42 #define ZLIB_VER_MAJOR 1 42 #define ZLIB_VER_MAJOR 1
43 #define ZLIB_VER_MINOR 2 43 #define ZLIB_VER_MINOR 2
44 #define ZLIB_VER_REVISION 13 << 44 #define ZLIB_VER_REVISION 11
45 #define ZLIB_VER_SUBREVISION 0 45 #define ZLIB_VER_SUBREVISION 0
46 46
47 /* 47 /*
48 The 'zlib' compression library provides in 48 The 'zlib' compression library provides in-memory compression and
49 decompression functions, including integrity 49 decompression functions, including integrity checks of the uncompressed data.
50 This version of the library supports only on 50 This version of the library supports only one compression method (deflation)
51 but other algorithms will be added later and 51 but other algorithms will be added later and will have the same stream
52 interface. 52 interface.
53 53
54 Compression can be done in a single step i 54 Compression can be done in a single step if the buffers are large enough,
55 or can be done by repeated calls of the comp 55 or can be done by repeated calls of the compression function. In the latter
56 case, the application must provide more inpu 56 case, the application must provide more input and/or consume the output
57 (providing more output space) before each ca 57 (providing more output space) before each call.
58 58
59 The compressed data format used by default 59 The compressed data format used by default by the in-memory functions is
60 the zlib format, which is a zlib wrapper doc 60 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
61 around a deflate stream, which is itself doc 61 around a deflate stream, which is itself documented in RFC 1951.
62 62
63 The library also supports reading and writ 63 The library also supports reading and writing files in gzip (.gz) format
64 with an interface similar to that of stdio u 64 with an interface similar to that of stdio using the functions that start
65 with "gz". The gzip format is different fro 65 with "gz". The gzip format is different from the zlib format. gzip is a
66 gzip wrapper, documented in RFC 1952, wrappe 66 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
67 67
68 This library can optionally read and write 68 This library can optionally read and write gzip and raw deflate streams in
69 memory as well. 69 memory as well.
70 70
71 The zlib format was designed to be compact 71 The zlib format was designed to be compact and fast for use in memory
72 and on communications channels. The gzip fo 72 and on communications channels. The gzip format was designed for single-
73 file compression on file systems, has a larg 73 file compression on file systems, has a larger header than zlib to maintain
74 directory information, and uses a different, 74 directory information, and uses a different, slower check method than zlib.
75 75
76 The library does not install any signal ha 76 The library does not install any signal handler. The decoder checks
77 the consistency of the compressed data, so t 77 the consistency of the compressed data, so the library should never crash
78 even in the case of corrupted input. 78 even in the case of corrupted input.
79 */ 79 */
80 80
81 typedef voidpf (*alloc_func) OF((voidpf opaque 81 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
82 typedef void (*free_func) OF((voidpf opaque 82 typedef void (*free_func) OF((voidpf opaque, voidpf address));
83 83
84 struct internal_state; 84 struct internal_state;
85 85
86 typedef struct z_stream_s { 86 typedef struct z_stream_s {
87 z_const Bytef *next_in; /* next input 87 z_const Bytef *next_in; /* next input byte */
88 uInt avail_in; /* number of bytes ava 88 uInt avail_in; /* number of bytes available at next_in */
89 uLong total_in; /* total number of inp 89 uLong total_in; /* total number of input bytes read so far */
90 90
91 Bytef *next_out; /* next output byte wi 91 Bytef *next_out; /* next output byte will go here */
92 uInt avail_out; /* remaining free spac 92 uInt avail_out; /* remaining free space at next_out */
93 uLong total_out; /* total number of byt 93 uLong total_out; /* total number of bytes output so far */
94 94
95 z_const char *msg; /* last error message, 95 z_const char *msg; /* last error message, NULL if no error */
96 struct internal_state FAR *state; /* not v 96 struct internal_state FAR *state; /* not visible by applications */
97 97
98 alloc_func zalloc; /* used to allocate th 98 alloc_func zalloc; /* used to allocate the internal state */
99 free_func zfree; /* used to free the in 99 free_func zfree; /* used to free the internal state */
100 voidpf opaque; /* private data object 100 voidpf opaque; /* private data object passed to zalloc and zfree */
101 101
102 int data_type; /* best guess about th 102 int data_type; /* best guess about the data type: binary or text
103 for deflate, or the 103 for deflate, or the decoding state for inflate */
104 uLong adler; /* Adler-32 or CRC-32 104 uLong adler; /* Adler-32 or CRC-32 value of the uncompressed data */
105 uLong reserved; /* reserved for future 105 uLong reserved; /* reserved for future use */
106 } z_stream; 106 } z_stream;
107 107
108 typedef z_stream FAR *z_streamp; 108 typedef z_stream FAR *z_streamp;
109 109
110 /* 110 /*
111 gzip header information passed to and fro 111 gzip header information passed to and from zlib routines. See RFC 1952
112 for more details on the meanings of these fi 112 for more details on the meanings of these fields.
113 */ 113 */
114 typedef struct gz_header_s { 114 typedef struct gz_header_s {
115 int text; /* true if compressed 115 int text; /* true if compressed data believed to be text */
116 uLong time; /* modification time * 116 uLong time; /* modification time */
117 int xflags; /* extra flags (not us 117 int xflags; /* extra flags (not used when writing a gzip file) */
118 int os; /* operating system */ 118 int os; /* operating system */
119 Bytef *extra; /* pointer to extra fi 119 Bytef *extra; /* pointer to extra field or Z_NULL if none */
120 uInt extra_len; /* extra field length 120 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
121 uInt extra_max; /* space at extra (onl 121 uInt extra_max; /* space at extra (only when reading header) */
122 Bytef *name; /* pointer to zero-ter 122 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
123 uInt name_max; /* space at name (only 123 uInt name_max; /* space at name (only when reading header) */
124 Bytef *comment; /* pointer to zero-ter 124 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
125 uInt comm_max; /* space at comment (o 125 uInt comm_max; /* space at comment (only when reading header) */
126 int hcrc; /* true if there was o 126 int hcrc; /* true if there was or will be a header crc */
127 int done; /* true when done read 127 int done; /* true when done reading gzip header (not used
128 when writing a gzip 128 when writing a gzip file) */
129 } gz_header; 129 } gz_header;
130 130
131 typedef gz_header FAR *gz_headerp; 131 typedef gz_header FAR *gz_headerp;
132 132
133 /* 133 /*
134 The application must update next_in and a 134 The application must update next_in and avail_in when avail_in has dropped
135 to zero. It must update next_out and avail 135 to zero. It must update next_out and avail_out when avail_out has dropped
136 to zero. The application must initialize z 136 to zero. The application must initialize zalloc, zfree and opaque before
137 calling the init function. All other field 137 calling the init function. All other fields are set by the compression
138 library and must not be updated by the appl 138 library and must not be updated by the application.
139 139
140 The opaque value provided by the applicat 140 The opaque value provided by the application will be passed as the first
141 parameter for calls of zalloc and zfree. T 141 parameter for calls of zalloc and zfree. This can be useful for custom
142 memory management. The compression library 142 memory management. The compression library attaches no meaning to the
143 opaque value. 143 opaque value.
144 144
145 zalloc must return Z_NULL if there is not 145 zalloc must return Z_NULL if there is not enough memory for the object.
146 If zlib is used in a multi-threaded applica 146 If zlib is used in a multi-threaded application, zalloc and zfree must be
147 thread safe. In that case, zlib is thread- 147 thread safe. In that case, zlib is thread-safe. When zalloc and zfree are
148 Z_NULL on entry to the initialization funct 148 Z_NULL on entry to the initialization function, they are set to internal
149 routines that use the standard library func 149 routines that use the standard library functions malloc() and free().
150 150
151 On 16-bit systems, the functions zalloc a 151 On 16-bit systems, the functions zalloc and zfree must be able to allocate
152 exactly 65536 bytes, but will not be requir 152 exactly 65536 bytes, but will not be required to allocate more than this if
153 the symbol MAXSEG_64K is defined (see zconf 153 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
154 returned by zalloc for objects of exactly 6 154 returned by zalloc for objects of exactly 65536 bytes *must* have their
155 offset normalized to zero. The default all 155 offset normalized to zero. The default allocation function provided by this
156 library ensures this (see zutil.c). To red 156 library ensures this (see zutil.c). To reduce memory requirements and avoid
157 any allocation of 64K objects, at the expen 157 any allocation of 64K objects, at the expense of compression ratio, compile
158 the library with -DMAX_WBITS=14 (see zconf. 158 the library with -DMAX_WBITS=14 (see zconf.h).
159 159
160 The fields total_in and total_out can be 160 The fields total_in and total_out can be used for statistics or progress
161 reports. After compression, total_in holds 161 reports. After compression, total_in holds the total size of the
162 uncompressed data and may be saved for use 162 uncompressed data and may be saved for use by the decompressor (particularly
163 if the decompressor wants to decompress eve 163 if the decompressor wants to decompress everything in a single step).
164 */ 164 */
165 165
166 /* constants */ 166 /* constants */
167 167
168 #define Z_NO_FLUSH 0 168 #define Z_NO_FLUSH 0
169 #define Z_PARTIAL_FLUSH 1 169 #define Z_PARTIAL_FLUSH 1
170 #define Z_SYNC_FLUSH 2 170 #define Z_SYNC_FLUSH 2
171 #define Z_FULL_FLUSH 3 171 #define Z_FULL_FLUSH 3
172 #define Z_FINISH 4 172 #define Z_FINISH 4
173 #define Z_BLOCK 5 173 #define Z_BLOCK 5
174 #define Z_TREES 6 174 #define Z_TREES 6
175 /* Allowed flush values; see deflate() and inf 175 /* Allowed flush values; see deflate() and inflate() below for details */
176 176
177 #define Z_OK 0 177 #define Z_OK 0
178 #define Z_STREAM_END 1 178 #define Z_STREAM_END 1
179 #define Z_NEED_DICT 2 179 #define Z_NEED_DICT 2
180 #define Z_ERRNO (-1) 180 #define Z_ERRNO (-1)
181 #define Z_STREAM_ERROR (-2) 181 #define Z_STREAM_ERROR (-2)
182 #define Z_DATA_ERROR (-3) 182 #define Z_DATA_ERROR (-3)
183 #define Z_MEM_ERROR (-4) 183 #define Z_MEM_ERROR (-4)
184 #define Z_BUF_ERROR (-5) 184 #define Z_BUF_ERROR (-5)
185 #define Z_VERSION_ERROR (-6) 185 #define Z_VERSION_ERROR (-6)
186 /* Return codes for the compression/decompress 186 /* Return codes for the compression/decompression functions. Negative values
187 * are errors, positive values are used for sp 187 * are errors, positive values are used for special but normal events.
188 */ 188 */
189 189
190 #define Z_NO_COMPRESSION 0 190 #define Z_NO_COMPRESSION 0
191 #define Z_BEST_SPEED 1 191 #define Z_BEST_SPEED 1
192 #define Z_BEST_COMPRESSION 9 192 #define Z_BEST_COMPRESSION 9
193 #define Z_DEFAULT_COMPRESSION (-1) 193 #define Z_DEFAULT_COMPRESSION (-1)
194 /* compression levels */ 194 /* compression levels */
195 195
196 #define Z_FILTERED 1 196 #define Z_FILTERED 1
197 #define Z_HUFFMAN_ONLY 2 197 #define Z_HUFFMAN_ONLY 2
198 #define Z_RLE 3 198 #define Z_RLE 3
199 #define Z_FIXED 4 199 #define Z_FIXED 4
200 #define Z_DEFAULT_STRATEGY 0 200 #define Z_DEFAULT_STRATEGY 0
201 /* compression strategy; see deflateInit2() be 201 /* compression strategy; see deflateInit2() below for details */
202 202
203 #define Z_BINARY 0 203 #define Z_BINARY 0
204 #define Z_TEXT 1 204 #define Z_TEXT 1
205 #define Z_ASCII Z_TEXT /* for compatibili 205 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
206 #define Z_UNKNOWN 2 206 #define Z_UNKNOWN 2
207 /* Possible values of the data_type field for 207 /* Possible values of the data_type field for deflate() */
208 208
209 #define Z_DEFLATED 8 209 #define Z_DEFLATED 8
210 /* The deflate compression method (the only on 210 /* The deflate compression method (the only one supported in this version) */
211 211
212 #define Z_NULL 0 /* for initializing zalloc, 212 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
213 213
214 #define zlib_version zlibVersion() 214 #define zlib_version zlibVersion()
215 /* for compatibility with versions < 1.0.2 */ 215 /* for compatibility with versions < 1.0.2 */
216 216
217 217
218 /* basic functions */ 218 /* basic functions */
219 219
220 ZEXTERN const char * ZEXPORT zlibVersion OF((v 220 ZEXTERN const char * ZEXPORT zlibVersion OF((void));
221 /* The application can compare zlibVersion and 221 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
222 If the first character differs, the library 222 If the first character differs, the library code actually used is not
223 compatible with the zlib.h header file used 223 compatible with the zlib.h header file used by the application. This check
224 is automatically made by deflateInit and in 224 is automatically made by deflateInit and inflateInit.
225 */ 225 */
226 226
227 /* 227 /*
228 ZEXTERN int ZEXPORT deflateInit OF((z_streamp 228 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
229 229
230 Initializes the internal stream state for 230 Initializes the internal stream state for compression. The fields
231 zalloc, zfree and opaque must be initialize 231 zalloc, zfree and opaque must be initialized before by the caller. If
232 zalloc and zfree are set to Z_NULL, deflate 232 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
233 allocation functions. 233 allocation functions.
234 234
235 The compression level must be Z_DEFAULT_C 235 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
236 1 gives best speed, 9 gives best compressio 236 1 gives best speed, 9 gives best compression, 0 gives no compression at all
237 (the input data is simply copied a block at 237 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
238 requests a default compromise between speed 238 requests a default compromise between speed and compression (currently
239 equivalent to level 6). 239 equivalent to level 6).
240 240
241 deflateInit returns Z_OK if success, Z_ME 241 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
242 memory, Z_STREAM_ERROR if level is not a va 242 memory, Z_STREAM_ERROR if level is not a valid compression level, or
243 Z_VERSION_ERROR if the zlib library version 243 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
244 with the version assumed by the caller (ZLI 244 with the version assumed by the caller (ZLIB_VERSION). msg is set to null
245 if there is no error message. deflateInit 245 if there is no error message. deflateInit does not perform any compression:
246 this will be done by deflate(). 246 this will be done by deflate().
247 */ 247 */
248 248
249 249
250 ZEXTERN int ZEXPORT deflate OF((z_streamp strm 250 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
251 /* 251 /*
252 deflate compresses as much data as possibl 252 deflate compresses as much data as possible, and stops when the input
253 buffer becomes empty or the output buffer be 253 buffer becomes empty or the output buffer becomes full. It may introduce
254 some output latency (reading input without p 254 some output latency (reading input without producing any output) except when
255 forced to flush. 255 forced to flush.
256 256
257 The detailed semantics are as follows. de 257 The detailed semantics are as follows. deflate performs one or both of the
258 following actions: 258 following actions:
259 259
260 - Compress more input starting at next_in an 260 - Compress more input starting at next_in and update next_in and avail_in
261 accordingly. If not all input can be proc 261 accordingly. If not all input can be processed (because there is not
262 enough room in the output buffer), next_in 262 enough room in the output buffer), next_in and avail_in are updated and
263 processing will resume at this point for t 263 processing will resume at this point for the next call of deflate().
264 264
265 - Generate more output starting at next_out 265 - Generate more output starting at next_out and update next_out and avail_out
266 accordingly. This action is forced if the 266 accordingly. This action is forced if the parameter flush is non zero.
267 Forcing flush frequently degrades the comp 267 Forcing flush frequently degrades the compression ratio, so this parameter
268 should be set only when necessary. Some o 268 should be set only when necessary. Some output may be provided even if
269 flush is zero. 269 flush is zero.
270 270
271 Before the call of deflate(), the applicat 271 Before the call of deflate(), the application should ensure that at least
272 one of the actions is possible, by providing 272 one of the actions is possible, by providing more input and/or consuming more
273 output, and updating avail_in or avail_out a 273 output, and updating avail_in or avail_out accordingly; avail_out should
274 never be zero before the call. The applicat 274 never be zero before the call. The application can consume the compressed
275 output when it wants, for example when the o 275 output when it wants, for example when the output buffer is full (avail_out
276 == 0), or after each call of deflate(). If 276 == 0), or after each call of deflate(). If deflate returns Z_OK and with
277 zero avail_out, it must be called again afte 277 zero avail_out, it must be called again after making room in the output
278 buffer because there might be more output pe 278 buffer because there might be more output pending. See deflatePending(),
279 which can be used if desired to determine wh << 279 which can be used if desired to determine whether or not there is more ouput
280 in that case. 280 in that case.
281 281
282 Normally the parameter flush is set to Z_N 282 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
283 decide how much data to accumulate before pr 283 decide how much data to accumulate before producing output, in order to
284 maximize compression. 284 maximize compression.
285 285
286 If the parameter flush is set to Z_SYNC_FL 286 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
287 flushed to the output buffer and the output 287 flushed to the output buffer and the output is aligned on a byte boundary, so
288 that the decompressor can get all input data 288 that the decompressor can get all input data available so far. (In
289 particular avail_in is zero after the call i 289 particular avail_in is zero after the call if enough output space has been
290 provided before the call.) Flushing may degr 290 provided before the call.) Flushing may degrade compression for some
291 compression algorithms and so it should be u 291 compression algorithms and so it should be used only when necessary. This
292 completes the current deflate block and foll 292 completes the current deflate block and follows it with an empty stored block
293 that is three bits plus filler bits to the n 293 that is three bits plus filler bits to the next byte, followed by four bytes
294 (00 00 ff ff). 294 (00 00 ff ff).
295 295
296 If flush is set to Z_PARTIAL_FLUSH, all pe 296 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
297 output buffer, but the output is not aligned 297 output buffer, but the output is not aligned to a byte boundary. All of the
298 input data so far will be available to the d 298 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
299 This completes the current deflate block and 299 This completes the current deflate block and follows it with an empty fixed
300 codes block that is 10 bits long. This assu 300 codes block that is 10 bits long. This assures that enough bytes are output
301 in order for the decompressor to finish the 301 in order for the decompressor to finish the block before the empty fixed
302 codes block. 302 codes block.
303 303
304 If flush is set to Z_BLOCK, a deflate bloc 304 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
305 for Z_SYNC_FLUSH, but the output is not alig 305 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
306 seven bits of the current block are held to 306 seven bits of the current block are held to be written as the next byte after
307 the next deflate block is completed. In thi 307 the next deflate block is completed. In this case, the decompressor may not
308 be provided enough bits at this point in ord 308 be provided enough bits at this point in order to complete decompression of
309 the data provided so far to the compressor. 309 the data provided so far to the compressor. It may need to wait for the next
310 block to be emitted. This is for advanced a 310 block to be emitted. This is for advanced applications that need to control
311 the emission of deflate blocks. 311 the emission of deflate blocks.
312 312
313 If flush is set to Z_FULL_FLUSH, all outpu 313 If flush is set to Z_FULL_FLUSH, all output is flushed as with
314 Z_SYNC_FLUSH, and the compression state is r 314 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
315 restart from this point if previous compress 315 restart from this point if previous compressed data has been damaged or if
316 random access is desired. Using Z_FULL_FLUS 316 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
317 compression. 317 compression.
318 318
319 If deflate returns with avail_out == 0, th 319 If deflate returns with avail_out == 0, this function must be called again
320 with the same value of the flush parameter a 320 with the same value of the flush parameter and more output space (updated
321 avail_out), until the flush is complete (def 321 avail_out), until the flush is complete (deflate returns with non-zero
322 avail_out). In the case of a Z_FULL_FLUSH o 322 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
323 avail_out is greater than six to avoid repea 323 avail_out is greater than six to avoid repeated flush markers due to
324 avail_out == 0 on return. 324 avail_out == 0 on return.
325 325
326 If the parameter flush is set to Z_FINISH, 326 If the parameter flush is set to Z_FINISH, pending input is processed,
327 pending output is flushed and deflate return 327 pending output is flushed and deflate returns with Z_STREAM_END if there was
328 enough output space. If deflate returns wit 328 enough output space. If deflate returns with Z_OK or Z_BUF_ERROR, this
329 function must be called again with Z_FINISH 329 function must be called again with Z_FINISH and more output space (updated
330 avail_out) but no more input data, until it 330 avail_out) but no more input data, until it returns with Z_STREAM_END or an
331 error. After deflate has returned Z_STREAM_ 331 error. After deflate has returned Z_STREAM_END, the only possible operations
332 on the stream are deflateReset or deflateEnd 332 on the stream are deflateReset or deflateEnd.
333 333
334 Z_FINISH can be used in the first deflate 334 Z_FINISH can be used in the first deflate call after deflateInit if all the
335 compression is to be done in a single step. 335 compression is to be done in a single step. In order to complete in one
336 call, avail_out must be at least the value r 336 call, avail_out must be at least the value returned by deflateBound (see
337 below). Then deflate is guaranteed to retur 337 below). Then deflate is guaranteed to return Z_STREAM_END. If not enough
338 output space is provided, deflate will not r 338 output space is provided, deflate will not return Z_STREAM_END, and it must
339 be called again as described above. 339 be called again as described above.
340 340
341 deflate() sets strm->adler to the Adler-32 341 deflate() sets strm->adler to the Adler-32 checksum of all input read
342 so far (that is, total_in bytes). If a gzip 342 so far (that is, total_in bytes). If a gzip stream is being generated, then
343 strm->adler will be the CRC-32 checksum of t 343 strm->adler will be the CRC-32 checksum of the input read so far. (See
344 deflateInit2 below.) 344 deflateInit2 below.)
345 345
346 deflate() may update strm->data_type if it 346 deflate() may update strm->data_type if it can make a good guess about
347 the input data type (Z_BINARY or Z_TEXT). I 347 the input data type (Z_BINARY or Z_TEXT). If in doubt, the data is
348 considered binary. This field is only for i 348 considered binary. This field is only for information purposes and does not
349 affect the compression algorithm in any mann 349 affect the compression algorithm in any manner.
350 350
351 deflate() returns Z_OK if some progress ha 351 deflate() returns Z_OK if some progress has been made (more input
352 processed or more output produced), Z_STREAM 352 processed or more output produced), Z_STREAM_END if all input has been
353 consumed and all output has been produced (o 353 consumed and all output has been produced (only when flush is set to
354 Z_FINISH), Z_STREAM_ERROR if the stream stat 354 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
355 if next_in or next_out was Z_NULL or the sta 355 if next_in or next_out was Z_NULL or the state was inadvertently written over
356 by the application), or Z_BUF_ERROR if no pr 356 by the application), or Z_BUF_ERROR if no progress is possible (for example
357 avail_in or avail_out was zero). Note that 357 avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and
358 deflate() can be called again with more inpu 358 deflate() can be called again with more input and more output space to
359 continue compressing. 359 continue compressing.
360 */ 360 */
361 361
362 362
363 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp s 363 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
364 /* 364 /*
365 All dynamically allocated data structures 365 All dynamically allocated data structures for this stream are freed.
366 This function discards any unprocessed inpu 366 This function discards any unprocessed input and does not flush any pending
367 output. 367 output.
368 368
369 deflateEnd returns Z_OK if success, Z_STR 369 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
370 stream state was inconsistent, Z_DATA_ERROR 370 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
371 prematurely (some input or output was disca 371 prematurely (some input or output was discarded). In the error case, msg
372 may be set but then points to a static stri 372 may be set but then points to a static string (which must not be
373 deallocated). 373 deallocated).
374 */ 374 */
375 375
376 376
377 /* 377 /*
378 ZEXTERN int ZEXPORT inflateInit OF((z_streamp 378 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
379 379
380 Initializes the internal stream state for 380 Initializes the internal stream state for decompression. The fields
381 next_in, avail_in, zalloc, zfree and opaque 381 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
382 the caller. In the current version of infl 382 the caller. In the current version of inflate, the provided input is not
383 read or consumed. The allocation of a slid 383 read or consumed. The allocation of a sliding window will be deferred to
384 the first call of inflate (if the decompres 384 the first call of inflate (if the decompression does not complete on the
385 first call). If zalloc and zfree are set t 385 first call). If zalloc and zfree are set to Z_NULL, inflateInit updates
386 them to use default allocation functions. 386 them to use default allocation functions.
387 387
388 inflateInit returns Z_OK if success, Z_ME 388 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
389 memory, Z_VERSION_ERROR if the zlib library 389 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
390 version assumed by the caller, or Z_STREAM_ 390 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
391 invalid, such as a null pointer to the stru 391 invalid, such as a null pointer to the structure. msg is set to null if
392 there is no error message. inflateInit doe 392 there is no error message. inflateInit does not perform any decompression.
393 Actual decompression will be done by inflat 393 Actual decompression will be done by inflate(). So next_in, and avail_in,
394 next_out, and avail_out are unused and unch 394 next_out, and avail_out are unused and unchanged. The current
395 implementation of inflateInit() does not pr 395 implementation of inflateInit() does not process any header information --
396 that is deferred until inflate() is called. 396 that is deferred until inflate() is called.
397 */ 397 */
398 398
399 399
400 ZEXTERN int ZEXPORT inflate OF((z_streamp strm 400 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
401 /* 401 /*
402 inflate decompresses as much data as possi 402 inflate decompresses as much data as possible, and stops when the input
403 buffer becomes empty or the output buffer be 403 buffer becomes empty or the output buffer becomes full. It may introduce
404 some output latency (reading input without p 404 some output latency (reading input without producing any output) except when
405 forced to flush. 405 forced to flush.
406 406
407 The detailed semantics are as follows. infl 407 The detailed semantics are as follows. inflate performs one or both of the
408 following actions: 408 following actions:
409 409
410 - Decompress more input starting at next_in 410 - Decompress more input starting at next_in and update next_in and avail_in
411 accordingly. If not all input can be proc 411 accordingly. If not all input can be processed (because there is not
412 enough room in the output buffer), then ne 412 enough room in the output buffer), then next_in and avail_in are updated
413 accordingly, and processing will resume at 413 accordingly, and processing will resume at this point for the next call of
414 inflate(). 414 inflate().
415 415
416 - Generate more output starting at next_out 416 - Generate more output starting at next_out and update next_out and avail_out
417 accordingly. inflate() provides as much o 417 accordingly. inflate() provides as much output as possible, until there is
418 no more input data or no more space in the 418 no more input data or no more space in the output buffer (see below about
419 the flush parameter). 419 the flush parameter).
420 420
421 Before the call of inflate(), the applicat 421 Before the call of inflate(), the application should ensure that at least
422 one of the actions is possible, by providing 422 one of the actions is possible, by providing more input and/or consuming more
423 output, and updating the next_* and avail_* 423 output, and updating the next_* and avail_* values accordingly. If the
424 caller of inflate() does not provide both av 424 caller of inflate() does not provide both available input and available
425 output space, it is possible that there will 425 output space, it is possible that there will be no progress made. The
426 application can consume the uncompressed out 426 application can consume the uncompressed output when it wants, for example
427 when the output buffer is full (avail_out == 427 when the output buffer is full (avail_out == 0), or after each call of
428 inflate(). If inflate returns Z_OK and with 428 inflate(). If inflate returns Z_OK and with zero avail_out, it must be
429 called again after making room in the output 429 called again after making room in the output buffer because there might be
430 more output pending. 430 more output pending.
431 431
432 The flush parameter of inflate() can be Z_ 432 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
433 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests 433 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
434 output as possible to the output buffer. Z_ 434 output as possible to the output buffer. Z_BLOCK requests that inflate()
435 stop if and when it gets to the next deflate 435 stop if and when it gets to the next deflate block boundary. When decoding
436 the zlib or gzip format, this will cause inf 436 the zlib or gzip format, this will cause inflate() to return immediately
437 after the header and before the first block. 437 after the header and before the first block. When doing a raw inflate,
438 inflate() will go ahead and process the firs 438 inflate() will go ahead and process the first block, and will return when it
439 gets to the end of that block, or when it ru 439 gets to the end of that block, or when it runs out of data.
440 440
441 The Z_BLOCK option assists in appending to 441 The Z_BLOCK option assists in appending to or combining deflate streams.
442 To assist in this, on return inflate() alway 442 To assist in this, on return inflate() always sets strm->data_type to the
443 number of unused bits in the last byte taken 443 number of unused bits in the last byte taken from strm->next_in, plus 64 if
444 inflate() is currently decoding the last blo 444 inflate() is currently decoding the last block in the deflate stream, plus
445 128 if inflate() returned immediately after 445 128 if inflate() returned immediately after decoding an end-of-block code or
446 decoding the complete header up to just befo 446 decoding the complete header up to just before the first byte of the deflate
447 stream. The end-of-block will not be indica 447 stream. The end-of-block will not be indicated until all of the uncompressed
448 data from that block has been written to str 448 data from that block has been written to strm->next_out. The number of
449 unused bits may in general be greater than s 449 unused bits may in general be greater than seven, except when bit 7 of
450 data_type is set, in which case the number o 450 data_type is set, in which case the number of unused bits will be less than
451 eight. data_type is set as noted here every 451 eight. data_type is set as noted here every time inflate() returns for all
452 flush options, and so can be used to determi 452 flush options, and so can be used to determine the amount of currently
453 consumed input in bits. 453 consumed input in bits.
454 454
455 The Z_TREES option behaves as Z_BLOCK does 455 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
456 end of each deflate block header is reached, 456 end of each deflate block header is reached, before any actual data in that
457 block is decoded. This allows the caller to 457 block is decoded. This allows the caller to determine the length of the
458 deflate block header for later use in random 458 deflate block header for later use in random access within a deflate block.
459 256 is added to the value of strm->data_type 459 256 is added to the value of strm->data_type when inflate() returns
460 immediately after reaching the end of the de 460 immediately after reaching the end of the deflate block header.
461 461
462 inflate() should normally be called until 462 inflate() should normally be called until it returns Z_STREAM_END or an
463 error. However if all decompression is to b 463 error. However if all decompression is to be performed in a single step (a
464 single call of inflate), the parameter flush 464 single call of inflate), the parameter flush should be set to Z_FINISH. In
465 this case all pending input is processed and 465 this case all pending input is processed and all pending output is flushed;
466 avail_out must be large enough to hold all o 466 avail_out must be large enough to hold all of the uncompressed data for the
467 operation to complete. (The size of the unc 467 operation to complete. (The size of the uncompressed data may have been
468 saved by the compressor for this purpose.) 468 saved by the compressor for this purpose.) The use of Z_FINISH is not
469 required to perform an inflation in one step 469 required to perform an inflation in one step. However it may be used to
470 inform inflate that a faster approach can be 470 inform inflate that a faster approach can be used for the single inflate()
471 call. Z_FINISH also informs inflate to not 471 call. Z_FINISH also informs inflate to not maintain a sliding window if the
472 stream completes, which reduces inflate's me 472 stream completes, which reduces inflate's memory footprint. If the stream
473 does not complete, either because not all of 473 does not complete, either because not all of the stream is provided or not
474 enough output space is provided, then a slid 474 enough output space is provided, then a sliding window will be allocated and
475 inflate() can be called again to continue th 475 inflate() can be called again to continue the operation as if Z_NO_FLUSH had
476 been used. 476 been used.
477 477
478 In this implementation, inflate() always 478 In this implementation, inflate() always flushes as much output as
479 possible to the output buffer, and always us 479 possible to the output buffer, and always uses the faster approach on the
480 first call. So the effects of the flush par 480 first call. So the effects of the flush parameter in this implementation are
481 on the return value of inflate() as noted be 481 on the return value of inflate() as noted below, when inflate() returns early
482 when Z_BLOCK or Z_TREES is used, and when in 482 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
483 memory for a sliding window when Z_FINISH is 483 memory for a sliding window when Z_FINISH is used.
484 484
485 If a preset dictionary is needed after th 485 If a preset dictionary is needed after this call (see inflateSetDictionary
486 below), inflate sets strm->adler to the Adle 486 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
487 chosen by the compressor and returns Z_NEED_ 487 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
488 strm->adler to the Adler-32 checksum of all 488 strm->adler to the Adler-32 checksum of all output produced so far (that is,
489 total_out bytes) and returns Z_OK, Z_STREAM_ 489 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
490 below. At the end of the stream, inflate() 490 below. At the end of the stream, inflate() checks that its computed Adler-32
491 checksum is equal to that saved by the compr 491 checksum is equal to that saved by the compressor and returns Z_STREAM_END
492 only if the checksum is correct. 492 only if the checksum is correct.
493 493
494 inflate() can decompress and check either 494 inflate() can decompress and check either zlib-wrapped or gzip-wrapped
495 deflate data. The header type is detected a 495 deflate data. The header type is detected automatically, if requested when
496 initializing with inflateInit2(). Any infor 496 initializing with inflateInit2(). Any information contained in the gzip
497 header is not retained unless inflateGetHead 497 header is not retained unless inflateGetHeader() is used. When processing
498 gzip-wrapped deflate data, strm->adler32 is 498 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
499 produced so far. The CRC-32 is checked agai 499 produced so far. The CRC-32 is checked against the gzip trailer, as is the
500 uncompressed length, modulo 2^32. 500 uncompressed length, modulo 2^32.
501 501
502 inflate() returns Z_OK if some progress ha 502 inflate() returns Z_OK if some progress has been made (more input processed
503 or more output produced), Z_STREAM_END if th 503 or more output produced), Z_STREAM_END if the end of the compressed data has
504 been reached and all uncompressed output has 504 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
505 preset dictionary is needed at this point, Z 505 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
506 corrupted (input stream not conforming to th 506 corrupted (input stream not conforming to the zlib format or incorrect check
507 value, in which case strm->msg points to a s 507 value, in which case strm->msg points to a string with a more specific
508 error), Z_STREAM_ERROR if the stream structu 508 error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
509 next_in or next_out was Z_NULL, or the state 509 next_in or next_out was Z_NULL, or the state was inadvertently written over
510 by the application), Z_MEM_ERROR if there wa 510 by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
511 if no progress was possible or if there was 511 if no progress was possible or if there was not enough room in the output
512 buffer when Z_FINISH is used. Note that Z_B 512 buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
513 inflate() can be called again with more inpu 513 inflate() can be called again with more input and more output space to
514 continue decompressing. If Z_DATA_ERROR is 514 continue decompressing. If Z_DATA_ERROR is returned, the application may
515 then call inflateSync() to look for a good c 515 then call inflateSync() to look for a good compression block if a partial
516 recovery of the data is to be attempted. 516 recovery of the data is to be attempted.
517 */ 517 */
518 518
519 519
520 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp s 520 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
521 /* 521 /*
522 All dynamically allocated data structures 522 All dynamically allocated data structures for this stream are freed.
523 This function discards any unprocessed inpu 523 This function discards any unprocessed input and does not flush any pending
524 output. 524 output.
525 525
526 inflateEnd returns Z_OK if success, or Z_ 526 inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state
527 was inconsistent. 527 was inconsistent.
528 */ 528 */
529 529
530 530
531 /* Advanced functions 531 /* Advanced functions */
532 532
533 /* 533 /*
534 The following functions are needed only in 534 The following functions are needed only in some special applications.
535 */ 535 */
536 536
537 /* 537 /*
538 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp 538 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
539 int leve 539 int level,
540 int meth 540 int method,
541 int wind 541 int windowBits,
542 int memL 542 int memLevel,
543 int stra 543 int strategy));
544 544
545 This is another version of deflateInit wi 545 This is another version of deflateInit with more compression options. The
546 fields zalloc, zfree and opaque must be ini << 546 fields next_in, zalloc, zfree and opaque must be initialized before by the
>> 547 caller.
547 548
548 The method parameter is the compression m 549 The method parameter is the compression method. It must be Z_DEFLATED in
549 this version of the library. 550 this version of the library.
550 551
551 The windowBits parameter is the base two 552 The windowBits parameter is the base two logarithm of the window size
552 (the size of the history buffer). It shoul 553 (the size of the history buffer). It should be in the range 8..15 for this
553 version of the library. Larger values of t 554 version of the library. Larger values of this parameter result in better
554 compression at the expense of memory usage. 555 compression at the expense of memory usage. The default value is 15 if
555 deflateInit is used instead. 556 deflateInit is used instead.
556 557
557 For the current implementation of deflate 558 For the current implementation of deflate(), a windowBits value of 8 (a
558 window size of 256 bytes) is not supported. 559 window size of 256 bytes) is not supported. As a result, a request for 8
559 will result in 9 (a 512-byte window). In t 560 will result in 9 (a 512-byte window). In that case, providing 8 to
560 inflateInit2() will result in an error when 561 inflateInit2() will result in an error when the zlib header with 9 is
561 checked against the initialization of infla 562 checked against the initialization of inflate(). The remedy is to not use 8
562 with deflateInit2() with this initializatio 563 with deflateInit2() with this initialization, or at least in that case use 9
563 with inflateInit2(). 564 with inflateInit2().
564 565
565 windowBits can also be -8..-15 for raw de 566 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
566 determines the window size. deflate() will 567 determines the window size. deflate() will then generate raw deflate data
567 with no zlib header or trailer, and will no 568 with no zlib header or trailer, and will not compute a check value.
568 569
569 windowBits can also be greater than 15 fo 570 windowBits can also be greater than 15 for optional gzip encoding. Add
570 16 to windowBits to write a simple gzip hea 571 16 to windowBits to write a simple gzip header and trailer around the
571 compressed data instead of a zlib wrapper. 572 compressed data instead of a zlib wrapper. The gzip header will have no
572 file name, no extra data, no comment, no mo 573 file name, no extra data, no comment, no modification time (set to zero), no
573 header crc, and the operating system will b 574 header crc, and the operating system will be set to the appropriate value,
574 if the operating system was determined at c 575 if the operating system was determined at compile time. If a gzip stream is
575 being written, strm->adler is a CRC-32 inst 576 being written, strm->adler is a CRC-32 instead of an Adler-32.
576 577
577 For raw deflate or gzip encoding, a reque 578 For raw deflate or gzip encoding, a request for a 256-byte window is
578 rejected as invalid, since only the zlib he 579 rejected as invalid, since only the zlib header provides a means of
579 transmitting the window size to the decompr 580 transmitting the window size to the decompressor.
580 581
581 The memLevel parameter specifies how much 582 The memLevel parameter specifies how much memory should be allocated
582 for the internal compression state. memLev 583 for the internal compression state. memLevel=1 uses minimum memory but is
583 slow and reduces compression ratio; memLeve 584 slow and reduces compression ratio; memLevel=9 uses maximum memory for
584 optimal speed. The default value is 8. Se 585 optimal speed. The default value is 8. See zconf.h for total memory usage
585 as a function of windowBits and memLevel. 586 as a function of windowBits and memLevel.
586 587
587 The strategy parameter is used to tune th 588 The strategy parameter is used to tune the compression algorithm. Use the
588 value Z_DEFAULT_STRATEGY for normal data, Z 589 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
589 filter (or predictor), Z_HUFFMAN_ONLY to fo 590 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
590 string match), or Z_RLE to limit match dist 591 string match), or Z_RLE to limit match distances to one (run-length
591 encoding). Filtered data consists mostly o 592 encoding). Filtered data consists mostly of small values with a somewhat
592 random distribution. In this case, the com 593 random distribution. In this case, the compression algorithm is tuned to
593 compress them better. The effect of Z_FILT 594 compress them better. The effect of Z_FILTERED is to force more Huffman
594 coding and less string matching; it is some 595 coding and less string matching; it is somewhat intermediate between
595 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_R 596 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
596 fast as Z_HUFFMAN_ONLY, but give better com 597 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
597 strategy parameter only affects the compres 598 strategy parameter only affects the compression ratio but not the
598 correctness of the compressed output even i 599 correctness of the compressed output even if it is not set appropriately.
599 Z_FIXED prevents the use of dynamic Huffman 600 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
600 decoder for special applications. 601 decoder for special applications.
601 602
602 deflateInit2 returns Z_OK if success, Z_M 603 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
603 memory, Z_STREAM_ERROR if any parameter is 604 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
604 method), or Z_VERSION_ERROR if the zlib lib 605 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
605 incompatible with the version assumed by th 606 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
606 set to null if there is no error message. 607 set to null if there is no error message. deflateInit2 does not perform any
607 compression: this will be done by deflate() 608 compression: this will be done by deflate().
608 */ 609 */
609 610
610 ZEXTERN int ZEXPORT deflateSetDictionary OF((z 611 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
611 c 612 const Bytef *dictionary,
612 u 613 uInt dictLength));
613 /* 614 /*
614 Initializes the compression dictionary fr 615 Initializes the compression dictionary from the given byte sequence
615 without producing any compressed output. W 616 without producing any compressed output. When using the zlib format, this
616 function must be called immediately after d 617 function must be called immediately after deflateInit, deflateInit2 or
617 deflateReset, and before any call of deflat 618 deflateReset, and before any call of deflate. When doing raw deflate, this
618 function must be called either before any c 619 function must be called either before any call of deflate, or immediately
619 after the completion of a deflate block, i. 620 after the completion of a deflate block, i.e. after all input has been
620 consumed and all output has been delivered 621 consumed and all output has been delivered when using any of the flush
621 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FL 622 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The
622 compressor and decompressor must use exactl 623 compressor and decompressor must use exactly the same dictionary (see
623 inflateSetDictionary). 624 inflateSetDictionary).
624 625
625 The dictionary should consist of strings 626 The dictionary should consist of strings (byte sequences) that are likely
626 to be encountered later in the data to be c 627 to be encountered later in the data to be compressed, with the most commonly
627 used strings preferably put towards the end 628 used strings preferably put towards the end of the dictionary. Using a
628 dictionary is most useful when the data to 629 dictionary is most useful when the data to be compressed is short and can be
629 predicted with good accuracy; the data can 630 predicted with good accuracy; the data can then be compressed better than
630 with the default empty dictionary. 631 with the default empty dictionary.
631 632
632 Depending on the size of the compression 633 Depending on the size of the compression data structures selected by
633 deflateInit or deflateInit2, a part of the 634 deflateInit or deflateInit2, a part of the dictionary may in effect be
634 discarded, for example if the dictionary is 635 discarded, for example if the dictionary is larger than the window size
635 provided in deflateInit or deflateInit2. T 636 provided in deflateInit or deflateInit2. Thus the strings most likely to be
636 useful should be put at the end of the dict 637 useful should be put at the end of the dictionary, not at the front. In
637 addition, the current implementation of def 638 addition, the current implementation of deflate will use at most the window
638 size minus 262 bytes of the provided dictio 639 size minus 262 bytes of the provided dictionary.
639 640
640 Upon return of this function, strm->adler 641 Upon return of this function, strm->adler is set to the Adler-32 value
641 of the dictionary; the decompressor may lat 642 of the dictionary; the decompressor may later use this value to determine
642 which dictionary has been used by the compr 643 which dictionary has been used by the compressor. (The Adler-32 value
643 applies to the whole dictionary even if onl 644 applies to the whole dictionary even if only a subset of the dictionary is
644 actually used by the compressor.) If a raw 645 actually used by the compressor.) If a raw deflate was requested, then the
645 Adler-32 value is not computed and strm->ad 646 Adler-32 value is not computed and strm->adler is not set.
646 647
647 deflateSetDictionary returns Z_OK if succ 648 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
648 parameter is invalid (e.g. dictionary bein 649 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
649 inconsistent (for example if deflate has al 650 inconsistent (for example if deflate has already been called for this stream
650 or if not at a block boundary for raw defla 651 or if not at a block boundary for raw deflate). deflateSetDictionary does
651 not perform any compression: this will be d 652 not perform any compression: this will be done by deflate().
652 */ 653 */
653 654
654 ZEXTERN int ZEXPORT deflateGetDictionary OF((z 655 ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
655 B 656 Bytef *dictionary,
656 u 657 uInt *dictLength));
657 /* 658 /*
658 Returns the sliding dictionary being main 659 Returns the sliding dictionary being maintained by deflate. dictLength is
659 set to the number of bytes in the dictionar 660 set to the number of bytes in the dictionary, and that many bytes are copied
660 to dictionary. dictionary must have enough 661 to dictionary. dictionary must have enough space, where 32768 bytes is
661 always enough. If deflateGetDictionary() i 662 always enough. If deflateGetDictionary() is called with dictionary equal to
662 Z_NULL, then only the dictionary length is 663 Z_NULL, then only the dictionary length is returned, and nothing is copied.
663 Similarly, if dictLength is Z_NULL, then it << 664 Similary, if dictLength is Z_NULL, then it is not set.
664 665
665 deflateGetDictionary() may return a lengt 666 deflateGetDictionary() may return a length less than the window size, even
666 when more than the window size in input has 667 when more than the window size in input has been provided. It may return up
667 to 258 bytes less in that case, due to how 668 to 258 bytes less in that case, due to how zlib's implementation of deflate
668 manages the sliding window and lookahead fo 669 manages the sliding window and lookahead for matches, where matches can be
669 up to 258 bytes long. If the application ne 670 up to 258 bytes long. If the application needs the last window-size bytes of
670 input, then that would need to be saved by 671 input, then that would need to be saved by the application outside of zlib.
671 672
672 deflateGetDictionary returns Z_OK on succ 673 deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
673 stream state is inconsistent. 674 stream state is inconsistent.
674 */ 675 */
675 676
676 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp 677 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
677 z_streamp 678 z_streamp source));
678 /* 679 /*
679 Sets the destination stream as a complete 680 Sets the destination stream as a complete copy of the source stream.
680 681
681 This function can be useful when several 682 This function can be useful when several compression strategies will be
682 tried, for example when there are several w 683 tried, for example when there are several ways of pre-processing the input
683 data with a filter. The streams that will 684 data with a filter. The streams that will be discarded should then be freed
684 by calling deflateEnd. Note that deflateCo 685 by calling deflateEnd. Note that deflateCopy duplicates the internal
685 compression state which can be quite large, 686 compression state which can be quite large, so this strategy is slow and can
686 consume lots of memory. 687 consume lots of memory.
687 688
688 deflateCopy returns Z_OK if success, Z_ME 689 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
689 enough memory, Z_STREAM_ERROR if the source 690 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
690 (such as zalloc being Z_NULL). msg is left 691 (such as zalloc being Z_NULL). msg is left unchanged in both source and
691 destination. 692 destination.
692 */ 693 */
693 694
694 ZEXTERN int ZEXPORT deflateReset OF((z_streamp 695 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
695 /* 696 /*
696 This function is equivalent to deflateEnd 697 This function is equivalent to deflateEnd followed by deflateInit, but
697 does not free and reallocate the internal c 698 does not free and reallocate the internal compression state. The stream
698 will leave the compression level and any ot 699 will leave the compression level and any other attributes that may have been
699 set unchanged. 700 set unchanged.
700 701
701 deflateReset returns Z_OK if success, or 702 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
702 stream state was inconsistent (such as zall 703 stream state was inconsistent (such as zalloc or state being Z_NULL).
703 */ 704 */
704 705
705 ZEXTERN int ZEXPORT deflateParams OF((z_stream 706 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
706 int leve 707 int level,
707 int stra 708 int strategy));
708 /* 709 /*
709 Dynamically update the compression level 710 Dynamically update the compression level and compression strategy. The
710 interpretation of level and strategy is as 711 interpretation of level and strategy is as in deflateInit2(). This can be
711 used to switch between compression and stra 712 used to switch between compression and straight copy of the input data, or
712 to switch to a different kind of input data 713 to switch to a different kind of input data requiring a different strategy.
713 If the compression approach (which is a fun 714 If the compression approach (which is a function of the level) or the
714 strategy is changed, and if there have been << 715 strategy is changed, and if any input has been consumed in a previous
715 state was initialized or reset, then the in << 716 deflate() call, then the input available so far is compressed with the old
716 compressed with the old level and strategy << 717 level and strategy using deflate(strm, Z_BLOCK). There are three approaches
717 There are three approaches for the compress << 718 for the compression levels 0, 1..3, and 4..9 respectively. The new level
718 respectively. The new level and strategy w << 719 and strategy will take effect at the next call of deflate().
719 of deflate(). <<
720 720
721 If a deflate(strm, Z_BLOCK) is performed 721 If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
722 not have enough output space to complete, t 722 not have enough output space to complete, then the parameter change will not
723 take effect. In this case, deflateParams() 723 take effect. In this case, deflateParams() can be called again with the
724 same parameters and more output space to tr 724 same parameters and more output space to try again.
725 725
726 In order to assure a change in the parame 726 In order to assure a change in the parameters on the first try, the
727 deflate stream should be flushed using defl 727 deflate stream should be flushed using deflate() with Z_BLOCK or other flush
728 request until strm.avail_out is not zero, b 728 request until strm.avail_out is not zero, before calling deflateParams().
729 Then no more input data should be provided 729 Then no more input data should be provided before the deflateParams() call.
730 If this is done, the old level and strategy 730 If this is done, the old level and strategy will be applied to the data
731 compressed before deflateParams(), and the 731 compressed before deflateParams(), and the new level and strategy will be
732 applied to the the data compressed after de 732 applied to the the data compressed after deflateParams().
733 733
734 deflateParams returns Z_OK on success, Z_ 734 deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
735 state was inconsistent or if a parameter wa 735 state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
736 there was not enough output space to comple 736 there was not enough output space to complete the compression of the
737 available input data before a change in the 737 available input data before a change in the strategy or approach. Note that
738 in the case of a Z_BUF_ERROR, the parameter 738 in the case of a Z_BUF_ERROR, the parameters are not changed. A return
739 value of Z_BUF_ERROR is not fatal, in which 739 value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
740 retried with more output space. 740 retried with more output space.
741 */ 741 */
742 742
743 ZEXTERN int ZEXPORT deflateTune OF((z_streamp 743 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
744 int good_l 744 int good_length,
745 int max_la 745 int max_lazy,
746 int nice_l 746 int nice_length,
747 int max_ch 747 int max_chain));
748 /* 748 /*
749 Fine tune deflate's internal compression 749 Fine tune deflate's internal compression parameters. This should only be
750 used by someone who understands the algorit 750 used by someone who understands the algorithm used by zlib's deflate for
751 searching for the best matching string, and 751 searching for the best matching string, and even then only by the most
752 fanatic optimizer trying to squeeze out the 752 fanatic optimizer trying to squeeze out the last compressed bit for their
753 specific input data. Read the deflate.c so 753 specific input data. Read the deflate.c source code for the meaning of the
754 max_lazy, good_length, nice_length, and max 754 max_lazy, good_length, nice_length, and max_chain parameters.
755 755
756 deflateTune() can be called after deflate 756 deflateTune() can be called after deflateInit() or deflateInit2(), and
757 returns Z_OK on success, or Z_STREAM_ERROR 757 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
758 */ 758 */
759 759
760 ZEXTERN uLong ZEXPORT deflateBound OF((z_strea 760 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
761 uLong s 761 uLong sourceLen));
762 /* 762 /*
763 deflateBound() returns an upper bound on 763 deflateBound() returns an upper bound on the compressed size after
764 deflation of sourceLen bytes. It must be c 764 deflation of sourceLen bytes. It must be called after deflateInit() or
765 deflateInit2(), and after deflateSetHeader( 765 deflateInit2(), and after deflateSetHeader(), if used. This would be used
766 to allocate an output buffer for deflation 766 to allocate an output buffer for deflation in a single pass, and so would be
767 called before deflate(). If that first def 767 called before deflate(). If that first deflate() call is provided the
768 sourceLen input bytes, an output buffer all 768 sourceLen input bytes, an output buffer allocated to the size returned by
769 deflateBound(), and the flush value Z_FINIS 769 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
770 to return Z_STREAM_END. Note that it is po 770 to return Z_STREAM_END. Note that it is possible for the compressed size to
771 be larger than the value returned by deflat 771 be larger than the value returned by deflateBound() if flush options other
772 than Z_FINISH or Z_NO_FLUSH are used. 772 than Z_FINISH or Z_NO_FLUSH are used.
773 */ 773 */
774 774
775 ZEXTERN int ZEXPORT deflatePending OF((z_strea 775 ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
776 unsigne 776 unsigned *pending,
777 int *bi 777 int *bits));
778 /* 778 /*
779 deflatePending() returns the number of by 779 deflatePending() returns the number of bytes and bits of output that have
780 been generated, but not yet provided in the 780 been generated, but not yet provided in the available output. The bytes not
781 provided would be due to the available outp 781 provided would be due to the available output space having being consumed.
782 The number of bits of output not provided a 782 The number of bits of output not provided are between 0 and 7, where they
783 await more bits to join them in order to fi 783 await more bits to join them in order to fill out a full byte. If pending
784 or bits are Z_NULL, then those values are n 784 or bits are Z_NULL, then those values are not set.
785 785
786 deflatePending returns Z_OK if success, o 786 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
787 stream state was inconsistent. 787 stream state was inconsistent.
788 */ 788 */
789 789
790 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp 790 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
791 int bits, 791 int bits,
792 int value 792 int value));
793 /* 793 /*
794 deflatePrime() inserts bits in the deflat 794 deflatePrime() inserts bits in the deflate output stream. The intent
795 is that this function is used to start off 795 is that this function is used to start off the deflate output with the bits
796 leftover from a previous deflate stream whe 796 leftover from a previous deflate stream when appending to it. As such, this
797 function can only be used for raw deflate, 797 function can only be used for raw deflate, and must be used before the first
798 deflate() call after a deflateInit2() or de 798 deflate() call after a deflateInit2() or deflateReset(). bits must be less
799 than or equal to 16, and that many of the l 799 than or equal to 16, and that many of the least significant bits of value
800 will be inserted in the output. 800 will be inserted in the output.
801 801
802 deflatePrime returns Z_OK if success, Z_B 802 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
803 room in the internal buffer to insert the b 803 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
804 source stream state was inconsistent. 804 source stream state was inconsistent.
805 */ 805 */
806 806
807 ZEXTERN int ZEXPORT deflateSetHeader OF((z_str 807 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
808 gz_he 808 gz_headerp head));
809 /* 809 /*
810 deflateSetHeader() provides gzip header i 810 deflateSetHeader() provides gzip header information for when a gzip
811 stream is requested by deflateInit2(). def 811 stream is requested by deflateInit2(). deflateSetHeader() may be called
812 after deflateInit2() or deflateReset() and 812 after deflateInit2() or deflateReset() and before the first call of
813 deflate(). The text, time, os, extra field 813 deflate(). The text, time, os, extra field, name, and comment information
814 in the provided gz_header structure are wri 814 in the provided gz_header structure are written to the gzip header (xflag is
815 ignored -- the extra flags are set accordin 815 ignored -- the extra flags are set according to the compression level). The
816 caller must assure that, if not Z_NULL, nam 816 caller must assure that, if not Z_NULL, name and comment are terminated with
817 a zero byte, and that if extra is not Z_NUL 817 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
818 available there. If hcrc is true, a gzip h 818 available there. If hcrc is true, a gzip header crc is included. Note that
819 the current versions of the command-line ve 819 the current versions of the command-line version of gzip (up through version
820 1.3.x) do not support header crc's, and wil 820 1.3.x) do not support header crc's, and will report that it is a "multi-part
821 gzip file" and give up. 821 gzip file" and give up.
822 822
823 If deflateSetHeader is not used, the defa 823 If deflateSetHeader is not used, the default gzip header has text false,
824 the time set to zero, and os set to 255, wi 824 the time set to zero, and os set to 255, with no extra, name, or comment
825 fields. The gzip header is returned to the 825 fields. The gzip header is returned to the default state by deflateReset().
826 826
827 deflateSetHeader returns Z_OK if success, 827 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
828 stream state was inconsistent. 828 stream state was inconsistent.
829 */ 829 */
830 830
831 /* 831 /*
832 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp 832 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
833 int wind 833 int windowBits));
834 834
835 This is another version of inflateInit wi 835 This is another version of inflateInit with an extra parameter. The
836 fields next_in, avail_in, zalloc, zfree and 836 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
837 before by the caller. 837 before by the caller.
838 838
839 The windowBits parameter is the base two 839 The windowBits parameter is the base two logarithm of the maximum window
840 size (the size of the history buffer). It 840 size (the size of the history buffer). It should be in the range 8..15 for
841 this version of the library. The default v 841 this version of the library. The default value is 15 if inflateInit is used
842 instead. windowBits must be greater than o 842 instead. windowBits must be greater than or equal to the windowBits value
843 provided to deflateInit2() while compressin 843 provided to deflateInit2() while compressing, or it must be equal to 15 if
844 deflateInit2() was not used. If a compress 844 deflateInit2() was not used. If a compressed stream with a larger window
845 size is given as input, inflate() will retu 845 size is given as input, inflate() will return with the error code
846 Z_DATA_ERROR instead of trying to allocate 846 Z_DATA_ERROR instead of trying to allocate a larger window.
847 847
848 windowBits can also be zero to request th 848 windowBits can also be zero to request that inflate use the window size in
849 the zlib header of the compressed stream. 849 the zlib header of the compressed stream.
850 850
851 windowBits can also be -8..-15 for raw in 851 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
852 determines the window size. inflate() will 852 determines the window size. inflate() will then process raw deflate data,
853 not looking for a zlib or gzip header, not 853 not looking for a zlib or gzip header, not generating a check value, and not
854 looking for any check values for comparison 854 looking for any check values for comparison at the end of the stream. This
855 is for use with other formats that use the 855 is for use with other formats that use the deflate compressed data format
856 such as zip. Those formats provide their o 856 such as zip. Those formats provide their own check values. If a custom
857 format is developed using the raw deflate f 857 format is developed using the raw deflate format for compressed data, it is
858 recommended that a check value such as an A 858 recommended that a check value such as an Adler-32 or a CRC-32 be applied to
859 the uncompressed data as is done in the zli 859 the uncompressed data as is done in the zlib, gzip, and zip formats. For
860 most applications, the zlib format should b 860 most applications, the zlib format should be used as is. Note that comments
861 above on the use in deflateInit2() applies 861 above on the use in deflateInit2() applies to the magnitude of windowBits.
862 862
863 windowBits can also be greater than 15 fo 863 windowBits can also be greater than 15 for optional gzip decoding. Add
864 32 to windowBits to enable zlib and gzip de 864 32 to windowBits to enable zlib and gzip decoding with automatic header
865 detection, or add 16 to decode only the gzi 865 detection, or add 16 to decode only the gzip format (the zlib format will
866 return a Z_DATA_ERROR). If a gzip stream i 866 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
867 CRC-32 instead of an Adler-32. Unlike the 867 CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see
868 below), inflate() will *not* automatically << 868 below), inflate() will not automatically decode concatenated gzip streams.
869 inflate() will return Z_STREAM_END at the e << 869 inflate() will return Z_STREAM_END at the end of the gzip stream. The state
870 would need to be reset to continue decoding << 870 would need to be reset to continue decoding a subsequent gzip stream.
871 *must* be done if there is more data after <<
872 decompression to be compliant with the gzip <<
873 871
874 inflateInit2 returns Z_OK if success, Z_M 872 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
875 memory, Z_VERSION_ERROR if the zlib library 873 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
876 version assumed by the caller, or Z_STREAM_ 874 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
877 invalid, such as a null pointer to the stru 875 invalid, such as a null pointer to the structure. msg is set to null if
878 there is no error message. inflateInit2 do 876 there is no error message. inflateInit2 does not perform any decompression
879 apart from possibly reading the zlib header 877 apart from possibly reading the zlib header if present: actual decompression
880 will be done by inflate(). (So next_in and 878 will be done by inflate(). (So next_in and avail_in may be modified, but
881 next_out and avail_out are unused and uncha 879 next_out and avail_out are unused and unchanged.) The current implementation
882 of inflateInit2() does not process any head 880 of inflateInit2() does not process any header information -- that is
883 deferred until inflate() is called. 881 deferred until inflate() is called.
884 */ 882 */
885 883
886 ZEXTERN int ZEXPORT inflateSetDictionary OF((z 884 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
887 c 885 const Bytef *dictionary,
888 u 886 uInt dictLength));
889 /* 887 /*
890 Initializes the decompression dictionary 888 Initializes the decompression dictionary from the given uncompressed byte
891 sequence. This function must be called imm 889 sequence. This function must be called immediately after a call of inflate,
892 if that call returned Z_NEED_DICT. The dic 890 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
893 can be determined from the Adler-32 value r 891 can be determined from the Adler-32 value returned by that call of inflate.
894 The compressor and decompressor must use ex 892 The compressor and decompressor must use exactly the same dictionary (see
895 deflateSetDictionary). For raw inflate, th 893 deflateSetDictionary). For raw inflate, this function can be called at any
896 time to set the dictionary. If the provide 894 time to set the dictionary. If the provided dictionary is smaller than the
897 window and there is already data in the win 895 window and there is already data in the window, then the provided dictionary
898 will amend what's there. The application m 896 will amend what's there. The application must insure that the dictionary
899 that was used for compression is provided. 897 that was used for compression is provided.
900 898
901 inflateSetDictionary returns Z_OK if succ 899 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
902 parameter is invalid (e.g. dictionary bein 900 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
903 inconsistent, Z_DATA_ERROR if the given dic 901 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
904 expected one (incorrect Adler-32 value). i 902 expected one (incorrect Adler-32 value). inflateSetDictionary does not
905 perform any decompression: this will be don 903 perform any decompression: this will be done by subsequent calls of
906 inflate(). 904 inflate().
907 */ 905 */
908 906
909 ZEXTERN int ZEXPORT inflateGetDictionary OF((z 907 ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
910 B 908 Bytef *dictionary,
911 u 909 uInt *dictLength));
912 /* 910 /*
913 Returns the sliding dictionary being main 911 Returns the sliding dictionary being maintained by inflate. dictLength is
914 set to the number of bytes in the dictionar 912 set to the number of bytes in the dictionary, and that many bytes are copied
915 to dictionary. dictionary must have enough 913 to dictionary. dictionary must have enough space, where 32768 bytes is
916 always enough. If inflateGetDictionary() i 914 always enough. If inflateGetDictionary() is called with dictionary equal to
917 Z_NULL, then only the dictionary length is 915 Z_NULL, then only the dictionary length is returned, and nothing is copied.
918 Similarly, if dictLength is Z_NULL, then it << 916 Similary, if dictLength is Z_NULL, then it is not set.
919 917
920 inflateGetDictionary returns Z_OK on succ 918 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
921 stream state is inconsistent. 919 stream state is inconsistent.
922 */ 920 */
923 921
924 ZEXTERN int ZEXPORT inflateSync OF((z_streamp 922 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
925 /* 923 /*
926 Skips invalid compressed data until a pos 924 Skips invalid compressed data until a possible full flush point (see above
927 for the description of deflate with Z_FULL_ 925 for the description of deflate with Z_FULL_FLUSH) can be found, or until all
928 available input is skipped. No output is p 926 available input is skipped. No output is provided.
929 927
930 inflateSync searches for a 00 00 FF FF pa 928 inflateSync searches for a 00 00 FF FF pattern in the compressed data.
931 All full flush points have this pattern, bu 929 All full flush points have this pattern, but not all occurrences of this
932 pattern are full flush points. 930 pattern are full flush points.
933 931
934 inflateSync returns Z_OK if a possible fu 932 inflateSync returns Z_OK if a possible full flush point has been found,
935 Z_BUF_ERROR if no more input was provided, 933 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
936 has been found, or Z_STREAM_ERROR if the st 934 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
937 In the success case, the application may sa 935 In the success case, the application may save the current current value of
938 total_in which indicates where valid compre 936 total_in which indicates where valid compressed data was found. In the
939 error case, the application may repeatedly 937 error case, the application may repeatedly call inflateSync, providing more
940 input each time, until success or end of th 938 input each time, until success or end of the input data.
941 */ 939 */
942 940
943 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp 941 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
944 z_streamp 942 z_streamp source));
945 /* 943 /*
946 Sets the destination stream as a complete 944 Sets the destination stream as a complete copy of the source stream.
947 945
948 This function can be useful when randomly 946 This function can be useful when randomly accessing a large stream. The
949 first pass through the stream can periodica 947 first pass through the stream can periodically record the inflate state,
950 allowing restarting inflate at those points 948 allowing restarting inflate at those points when randomly accessing the
951 stream. 949 stream.
952 950
953 inflateCopy returns Z_OK if success, Z_ME 951 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
954 enough memory, Z_STREAM_ERROR if the source 952 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
955 (such as zalloc being Z_NULL). msg is left 953 (such as zalloc being Z_NULL). msg is left unchanged in both source and
956 destination. 954 destination.
957 */ 955 */
958 956
959 ZEXTERN int ZEXPORT inflateReset OF((z_streamp 957 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
960 /* 958 /*
961 This function is equivalent to inflateEnd 959 This function is equivalent to inflateEnd followed by inflateInit,
962 but does not free and reallocate the intern 960 but does not free and reallocate the internal decompression state. The
963 stream will keep attributes that may have b 961 stream will keep attributes that may have been set by inflateInit2.
964 962
965 inflateReset returns Z_OK if success, or 963 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
966 stream state was inconsistent (such as zall 964 stream state was inconsistent (such as zalloc or state being Z_NULL).
967 */ 965 */
968 966
969 ZEXTERN int ZEXPORT inflateReset2 OF((z_stream 967 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
970 int wind 968 int windowBits));
971 /* 969 /*
972 This function is the same as inflateReset 970 This function is the same as inflateReset, but it also permits changing
973 the wrap and window size requests. The win 971 the wrap and window size requests. The windowBits parameter is interpreted
974 the same as it is for inflateInit2. If the 972 the same as it is for inflateInit2. If the window size is changed, then the
975 memory allocated for the window is freed, a 973 memory allocated for the window is freed, and the window will be reallocated
976 by inflate() if needed. 974 by inflate() if needed.
977 975
978 inflateReset2 returns Z_OK if success, or 976 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
979 stream state was inconsistent (such as zall 977 stream state was inconsistent (such as zalloc or state being Z_NULL), or if
980 the windowBits parameter is invalid. 978 the windowBits parameter is invalid.
981 */ 979 */
982 980
983 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp 981 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
984 int bits, 982 int bits,
985 int value 983 int value));
986 /* 984 /*
987 This function inserts bits in the inflate 985 This function inserts bits in the inflate input stream. The intent is
988 that this function is used to start inflati 986 that this function is used to start inflating at a bit position in the
989 middle of a byte. The provided bits will b 987 middle of a byte. The provided bits will be used before any bytes are used
990 from next_in. This function should only be 988 from next_in. This function should only be used with raw inflate, and
991 should be used before the first inflate() c 989 should be used before the first inflate() call after inflateInit2() or
992 inflateReset(). bits must be less than or 990 inflateReset(). bits must be less than or equal to 16, and that many of the
993 least significant bits of value will be ins 991 least significant bits of value will be inserted in the input.
994 992
995 If bits is negative, then the input strea 993 If bits is negative, then the input stream bit buffer is emptied. Then
996 inflatePrime() can be called again to put b 994 inflatePrime() can be called again to put bits in the buffer. This is used
997 to clear out bits leftover after feeding in 995 to clear out bits leftover after feeding inflate a block description prior
998 to feeding inflate codes. 996 to feeding inflate codes.
999 997
1000 inflatePrime returns Z_OK if success, or 998 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
1001 stream state was inconsistent. 999 stream state was inconsistent.
1002 */ 1000 */
1003 1001
1004 ZEXTERN long ZEXPORT inflateMark OF((z_stream 1002 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
1005 /* 1003 /*
1006 This function returns two values, one in 1004 This function returns two values, one in the lower 16 bits of the return
1007 value, and the other in the remaining uppe 1005 value, and the other in the remaining upper bits, obtained by shifting the
1008 return value down 16 bits. If the upper v 1006 return value down 16 bits. If the upper value is -1 and the lower value is
1009 zero, then inflate() is currently decoding 1007 zero, then inflate() is currently decoding information outside of a block.
1010 If the upper value is -1 and the lower val 1008 If the upper value is -1 and the lower value is non-zero, then inflate is in
1011 the middle of a stored block, with the low 1009 the middle of a stored block, with the lower value equaling the number of
1012 bytes from the input remaining to copy. I 1010 bytes from the input remaining to copy. If the upper value is not -1, then
1013 it is the number of bits back from the cur 1011 it is the number of bits back from the current bit position in the input of
1014 the code (literal or length/distance pair) 1012 the code (literal or length/distance pair) currently being processed. In
1015 that case the lower value is the number of 1013 that case the lower value is the number of bytes already emitted for that
1016 code. 1014 code.
1017 1015
1018 A code is being processed if inflate is 1016 A code is being processed if inflate is waiting for more input to complete
1019 decoding of the code, or if it has complet 1017 decoding of the code, or if it has completed decoding but is waiting for
1020 more output space to write the literal or 1018 more output space to write the literal or match data.
1021 1019
1022 inflateMark() is used to mark locations 1020 inflateMark() is used to mark locations in the input data for random
1023 access, which may be at bit positions, and 1021 access, which may be at bit positions, and to note those cases where the
1024 output of a code may span boundaries of ra 1022 output of a code may span boundaries of random access blocks. The current
1025 location in the input stream can be determ 1023 location in the input stream can be determined from avail_in and data_type
1026 as noted in the description for the Z_BLOC 1024 as noted in the description for the Z_BLOCK flush parameter for inflate.
1027 1025
1028 inflateMark returns the value noted abov 1026 inflateMark returns the value noted above, or -65536 if the provided
1029 source stream state was inconsistent. 1027 source stream state was inconsistent.
1030 */ 1028 */
1031 1029
1032 ZEXTERN int ZEXPORT inflateGetHeader OF((z_st 1030 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
1033 gz_h 1031 gz_headerp head));
1034 /* 1032 /*
1035 inflateGetHeader() requests that gzip he 1033 inflateGetHeader() requests that gzip header information be stored in the
1036 provided gz_header structure. inflateGetH 1034 provided gz_header structure. inflateGetHeader() may be called after
1037 inflateInit2() or inflateReset(), and befo 1035 inflateInit2() or inflateReset(), and before the first call of inflate().
1038 As inflate() processes the gzip stream, he 1036 As inflate() processes the gzip stream, head->done is zero until the header
1039 is completed, at which time head->done is 1037 is completed, at which time head->done is set to one. If a zlib stream is
1040 being decoded, then head->done is set to - 1038 being decoded, then head->done is set to -1 to indicate that there will be
1041 no gzip header information forthcoming. N 1039 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
1042 used to force inflate() to return immediat 1040 used to force inflate() to return immediately after header processing is
1043 complete and before any actual data is dec 1041 complete and before any actual data is decompressed.
1044 1042
1045 The text, time, xflags, and os fields ar 1043 The text, time, xflags, and os fields are filled in with the gzip header
1046 contents. hcrc is set to true if there is 1044 contents. hcrc is set to true if there is a header CRC. (The header CRC
1047 was valid if done is set to one.) If extra 1045 was valid if done is set to one.) If extra is not Z_NULL, then extra_max
1048 contains the maximum number of bytes to wr 1046 contains the maximum number of bytes to write to extra. Once done is true,
1049 extra_len contains the actual extra field 1047 extra_len contains the actual extra field length, and extra contains the
1050 extra field, or that field truncated if ex 1048 extra field, or that field truncated if extra_max is less than extra_len.
1051 If name is not Z_NULL, then up to name_max 1049 If name is not Z_NULL, then up to name_max characters are written there,
1052 terminated with a zero unless the length i 1050 terminated with a zero unless the length is greater than name_max. If
1053 comment is not Z_NULL, then up to comm_max 1051 comment is not Z_NULL, then up to comm_max characters are written there,
1054 terminated with a zero unless the length i 1052 terminated with a zero unless the length is greater than comm_max. When any
1055 of extra, name, or comment are not Z_NULL 1053 of extra, name, or comment are not Z_NULL and the respective field is not
1056 present in the header, then that field is 1054 present in the header, then that field is set to Z_NULL to signal its
1057 absence. This allows the use of deflateSe 1055 absence. This allows the use of deflateSetHeader() with the returned
1058 structure to duplicate the header. Howeve 1056 structure to duplicate the header. However if those fields are set to
1059 allocated memory, then the application wil 1057 allocated memory, then the application will need to save those pointers
1060 elsewhere so that they can be eventually f 1058 elsewhere so that they can be eventually freed.
1061 1059
1062 If inflateGetHeader is not used, then th 1060 If inflateGetHeader is not used, then the header information is simply
1063 discarded. The header is always checked f 1061 discarded. The header is always checked for validity, including the header
1064 CRC if present. inflateReset() will reset 1062 CRC if present. inflateReset() will reset the process to discard the header
1065 information. The application would need t 1063 information. The application would need to call inflateGetHeader() again to
1066 retrieve the header from the next gzip str 1064 retrieve the header from the next gzip stream.
1067 1065
1068 inflateGetHeader returns Z_OK if success 1066 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
1069 stream state was inconsistent. 1067 stream state was inconsistent.
1070 */ 1068 */
1071 1069
1072 /* 1070 /*
1073 ZEXTERN int ZEXPORT inflateBackInit OF((z_str 1071 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
1074 unsig 1072 unsigned char FAR *window));
1075 1073
1076 Initialize the internal stream state for 1074 Initialize the internal stream state for decompression using inflateBack()
1077 calls. The fields zalloc, zfree and opaqu 1075 calls. The fields zalloc, zfree and opaque in strm must be initialized
1078 before the call. If zalloc and zfree are 1076 before the call. If zalloc and zfree are Z_NULL, then the default library-
1079 derived memory allocation routines are use 1077 derived memory allocation routines are used. windowBits is the base two
1080 logarithm of the window size, in the range 1078 logarithm of the window size, in the range 8..15. window is a caller
1081 supplied buffer of that size. Except for 1079 supplied buffer of that size. Except for special applications where it is
1082 assured that deflate was used with small w 1080 assured that deflate was used with small window sizes, windowBits must be 15
1083 and a 32K byte window must be supplied to 1081 and a 32K byte window must be supplied to be able to decompress general
1084 deflate streams. 1082 deflate streams.
1085 1083
1086 See inflateBack() for the usage of these 1084 See inflateBack() for the usage of these routines.
1087 1085
1088 inflateBackInit will return Z_OK on succ 1086 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
1089 the parameters are invalid, Z_MEM_ERROR if 1087 the parameters are invalid, Z_MEM_ERROR if the internal state could not be
1090 allocated, or Z_VERSION_ERROR if the versi 1088 allocated, or Z_VERSION_ERROR if the version of the library does not match
1091 the version of the header file. 1089 the version of the header file.
1092 */ 1090 */
1093 1091
1094 typedef unsigned (*in_func) OF((void FAR *, 1092 typedef unsigned (*in_func) OF((void FAR *,
1095 z_const unsig 1093 z_const unsigned char FAR * FAR *));
1096 typedef int (*out_func) OF((void FAR *, unsig 1094 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
1097 1095
1098 ZEXTERN int ZEXPORT inflateBack OF((z_streamp 1096 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
1099 in_func i 1097 in_func in, void FAR *in_desc,
1100 out_func 1098 out_func out, void FAR *out_desc));
1101 /* 1099 /*
1102 inflateBack() does a raw inflate with a 1100 inflateBack() does a raw inflate with a single call using a call-back
1103 interface for input and output. This is p 1101 interface for input and output. This is potentially more efficient than
1104 inflate() for file i/o applications, in th 1102 inflate() for file i/o applications, in that it avoids copying between the
1105 output and the sliding window by simply ma 1103 output and the sliding window by simply making the window itself the output
1106 buffer. inflate() can be faster on modern 1104 buffer. inflate() can be faster on modern CPUs when used with large
1107 buffers. inflateBack() trusts the applica 1105 buffers. inflateBack() trusts the application to not change the output
1108 buffer passed by the output function, at l 1106 buffer passed by the output function, at least until inflateBack() returns.
1109 1107
1110 inflateBackInit() must be called first t 1108 inflateBackInit() must be called first to allocate the internal state
1111 and to initialize the state with the user- 1109 and to initialize the state with the user-provided window buffer.
1112 inflateBack() may then be used multiple ti 1110 inflateBack() may then be used multiple times to inflate a complete, raw
1113 deflate stream with each call. inflateBac 1111 deflate stream with each call. inflateBackEnd() is then called to free the
1114 allocated state. 1112 allocated state.
1115 1113
1116 A raw deflate stream is one with no zlib 1114 A raw deflate stream is one with no zlib or gzip header or trailer.
1117 This routine would normally be used in a u 1115 This routine would normally be used in a utility that reads zip or gzip
1118 files and writes out uncompressed files. 1116 files and writes out uncompressed files. The utility would decode the
1119 header and process the trailer on its own, 1117 header and process the trailer on its own, hence this routine expects only
1120 the raw deflate stream to decompress. Thi 1118 the raw deflate stream to decompress. This is different from the default
1121 behavior of inflate(), which expects a zli 1119 behavior of inflate(), which expects a zlib header and trailer around the
1122 deflate stream. 1120 deflate stream.
1123 1121
1124 inflateBack() uses two subroutines suppl 1122 inflateBack() uses two subroutines supplied by the caller that are then
1125 called by inflateBack() for input and outp 1123 called by inflateBack() for input and output. inflateBack() calls those
1126 routines until it reads a complete deflate 1124 routines until it reads a complete deflate stream and writes out all of the
1127 uncompressed data, or until it encounters 1125 uncompressed data, or until it encounters an error. The function's
1128 parameters and return types are defined ab 1126 parameters and return types are defined above in the in_func and out_func
1129 typedefs. inflateBack() will call in(in_d 1127 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
1130 number of bytes of provided input, and a p 1128 number of bytes of provided input, and a pointer to that input in buf. If
1131 there is no input available, in() must ret 1129 there is no input available, in() must return zero -- buf is ignored in that
1132 case -- and inflateBack() will return a bu 1130 case -- and inflateBack() will return a buffer error. inflateBack() will
1133 call out(out_desc, buf, len) to write the 1131 call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
1134 out() should return zero on success, or no 1132 out() should return zero on success, or non-zero on failure. If out()
1135 returns non-zero, inflateBack() will retur 1133 returns non-zero, inflateBack() will return with an error. Neither in() nor
1136 out() are permitted to change the contents 1134 out() are permitted to change the contents of the window provided to
1137 inflateBackInit(), which is also the buffe 1135 inflateBackInit(), which is also the buffer that out() uses to write from.
1138 The length written by out() will be at mos 1136 The length written by out() will be at most the window size. Any non-zero
1139 amount of input may be provided by in(). 1137 amount of input may be provided by in().
1140 1138
1141 For convenience, inflateBack() can be pr 1139 For convenience, inflateBack() can be provided input on the first call by
1142 setting strm->next_in and strm->avail_in. 1140 setting strm->next_in and strm->avail_in. If that input is exhausted, then
1143 in() will be called. Therefore strm->next 1141 in() will be called. Therefore strm->next_in must be initialized before
1144 calling inflateBack(). If strm->next_in i 1142 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
1145 immediately for input. If strm->next_in i 1143 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
1146 must also be initialized, and then if strm 1144 must also be initialized, and then if strm->avail_in is not zero, input will
1147 initially be taken from strm->next_in[0 .. 1145 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
1148 1146
1149 The in_desc and out_desc parameters of i 1147 The in_desc and out_desc parameters of inflateBack() is passed as the
1150 first parameter of in() and out() respecti 1148 first parameter of in() and out() respectively when they are called. These
1151 descriptors can be optionally used to pass 1149 descriptors can be optionally used to pass any information that the caller-
1152 supplied in() and out() functions need to 1150 supplied in() and out() functions need to do their job.
1153 1151
1154 On return, inflateBack() will set strm-> 1152 On return, inflateBack() will set strm->next_in and strm->avail_in to
1155 pass back any unused input that was provid 1153 pass back any unused input that was provided by the last in() call. The
1156 return values of inflateBack() can be Z_ST 1154 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
1157 if in() or out() returned an error, Z_DATA 1155 if in() or out() returned an error, Z_DATA_ERROR if there was a format error
1158 in the deflate stream (in which case strm- 1156 in the deflate stream (in which case strm->msg is set to indicate the nature
1159 of the error), or Z_STREAM_ERROR if the st 1157 of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
1160 In the case of Z_BUF_ERROR, an input or ou 1158 In the case of Z_BUF_ERROR, an input or output error can be distinguished
1161 using strm->next_in which will be Z_NULL o 1159 using strm->next_in which will be Z_NULL only if in() returned an error. If
1162 strm->next_in is not Z_NULL, then the Z_BU 1160 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1163 non-zero. (in() will always be called bef 1161 non-zero. (in() will always be called before out(), so strm->next_in is
1164 assured to be defined if out() returns non 1162 assured to be defined if out() returns non-zero.) Note that inflateBack()
1165 cannot return Z_OK. 1163 cannot return Z_OK.
1166 */ 1164 */
1167 1165
1168 ZEXTERN int ZEXPORT inflateBackEnd OF((z_stre 1166 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
1169 /* 1167 /*
1170 All memory allocated by inflateBackInit( 1168 All memory allocated by inflateBackInit() is freed.
1171 1169
1172 inflateBackEnd() returns Z_OK on success 1170 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
1173 state was inconsistent. 1171 state was inconsistent.
1174 */ 1172 */
1175 1173
1176 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((vo 1174 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
1177 /* Return flags indicating compile-time optio 1175 /* Return flags indicating compile-time options.
1178 1176
1179 Type sizes, two bits each, 00 = 16 bits, 1177 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1180 1.0: size of uInt 1178 1.0: size of uInt
1181 3.2: size of uLong 1179 3.2: size of uLong
1182 5.4: size of voidpf (pointer) 1180 5.4: size of voidpf (pointer)
1183 7.6: size of z_off_t 1181 7.6: size of z_off_t
1184 1182
1185 Compiler, assembler, and debug options: 1183 Compiler, assembler, and debug options:
1186 8: ZLIB_DEBUG 1184 8: ZLIB_DEBUG
1187 9: ASMV or ASMINF -- use ASM code 1185 9: ASMV or ASMINF -- use ASM code
1188 10: ZLIB_WINAPI -- exported functions us 1186 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1189 11: 0 (reserved) 1187 11: 0 (reserved)
1190 1188
1191 One-time table building (smaller code, bu 1189 One-time table building (smaller code, but not thread-safe if true):
1192 12: BUILDFIXED -- build static block dec 1190 12: BUILDFIXED -- build static block decoding tables when needed
1193 13: DYNAMIC_CRC_TABLE -- build CRC calcu 1191 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1194 14,15: 0 (reserved) 1192 14,15: 0 (reserved)
1195 1193
1196 Library content (indicates missing functi 1194 Library content (indicates missing functionality):
1197 16: NO_GZCOMPRESS -- gz* functions canno 1195 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1198 deflate code when n 1196 deflate code when not needed)
1199 17: NO_GZIP -- deflate can't write gzip 1197 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1200 and decode gzip streams ( 1198 and decode gzip streams (to avoid linking crc code)
1201 18-19: 0 (reserved) 1199 18-19: 0 (reserved)
1202 1200
1203 Operation variations (changes in library 1201 Operation variations (changes in library functionality):
1204 20: PKZIP_BUG_WORKAROUND -- slightly mor 1202 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1205 21: FASTEST -- deflate algorithm with on 1203 21: FASTEST -- deflate algorithm with only one, lowest compression level
1206 22,23: 0 (reserved) 1204 22,23: 0 (reserved)
1207 1205
1208 The sprintf variant used by gzprintf (zer 1206 The sprintf variant used by gzprintf (zero is best):
1209 24: 0 = vs*, 1 = s* -- 1 means limited t 1207 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1210 25: 0 = *nprintf, 1 = *printf -- 1 means 1208 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1211 26: 0 = returns value, 1 = void -- 1 mea 1209 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1212 1210
1213 Remainder: 1211 Remainder:
1214 27-31: 0 (reserved) 1212 27-31: 0 (reserved)
1215 */ 1213 */
1216 1214
1217 #ifndef Z_SOLO 1215 #ifndef Z_SOLO
1218 1216
1219 /* utility functions 1217 /* utility functions */
1220 1218
1221 /* 1219 /*
1222 The following utility functions are impl 1220 The following utility functions are implemented on top of the basic
1223 stream-oriented functions. To simplify th 1221 stream-oriented functions. To simplify the interface, some default options
1224 are assumed (compression level and memory 1222 are assumed (compression level and memory usage, standard memory allocation
1225 functions). The source code of these util 1223 functions). The source code of these utility functions can be modified if
1226 you need special options. 1224 you need special options.
1227 */ 1225 */
1228 1226
1229 ZEXTERN int ZEXPORT compress OF((Bytef *dest, 1227 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
1230 const Bytef 1228 const Bytef *source, uLong sourceLen));
1231 /* 1229 /*
1232 Compresses the source buffer into the de 1230 Compresses the source buffer into the destination buffer. sourceLen is
1233 the byte length of the source buffer. Upo 1231 the byte length of the source buffer. Upon entry, destLen is the total size
1234 of the destination buffer, which must be a 1232 of the destination buffer, which must be at least the value returned by
1235 compressBound(sourceLen). Upon exit, dest 1233 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1236 compressed data. compress() is equivalent 1234 compressed data. compress() is equivalent to compress2() with a level
1237 parameter of Z_DEFAULT_COMPRESSION. 1235 parameter of Z_DEFAULT_COMPRESSION.
1238 1236
1239 compress returns Z_OK if success, Z_MEM_ 1237 compress returns Z_OK if success, Z_MEM_ERROR if there was not
1240 enough memory, Z_BUF_ERROR if there was no 1238 enough memory, Z_BUF_ERROR if there was not enough room in the output
1241 buffer. 1239 buffer.
1242 */ 1240 */
1243 1241
1244 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest 1242 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
1245 const Bytef 1243 const Bytef *source, uLong sourceLen,
1246 int level)) 1244 int level));
1247 /* 1245 /*
1248 Compresses the source buffer into the de 1246 Compresses the source buffer into the destination buffer. The level
1249 parameter has the same meaning as in defla 1247 parameter has the same meaning as in deflateInit. sourceLen is the byte
1250 length of the source buffer. Upon entry, 1248 length of the source buffer. Upon entry, destLen is the total size of the
1251 destination buffer, which must be at least 1249 destination buffer, which must be at least the value returned by
1252 compressBound(sourceLen). Upon exit, dest 1250 compressBound(sourceLen). Upon exit, destLen is the actual size of the
1253 compressed data. 1251 compressed data.
1254 1252
1255 compress2 returns Z_OK if success, Z_MEM 1253 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1256 memory, Z_BUF_ERROR if there was not enoug 1254 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1257 Z_STREAM_ERROR if the level parameter is i 1255 Z_STREAM_ERROR if the level parameter is invalid.
1258 */ 1256 */
1259 1257
1260 ZEXTERN uLong ZEXPORT compressBound OF((uLong 1258 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1261 /* 1259 /*
1262 compressBound() returns an upper bound o 1260 compressBound() returns an upper bound on the compressed size after
1263 compress() or compress2() on sourceLen byt 1261 compress() or compress2() on sourceLen bytes. It would be used before a
1264 compress() or compress2() call to allocate 1262 compress() or compress2() call to allocate the destination buffer.
1265 */ 1263 */
1266 1264
1267 ZEXTERN int ZEXPORT uncompress OF((Bytef *des 1265 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
1268 const Byte 1266 const Bytef *source, uLong sourceLen));
1269 /* 1267 /*
1270 Decompresses the source buffer into the 1268 Decompresses the source buffer into the destination buffer. sourceLen is
1271 the byte length of the source buffer. Upo 1269 the byte length of the source buffer. Upon entry, destLen is the total size
1272 of the destination buffer, which must be l 1270 of the destination buffer, which must be large enough to hold the entire
1273 uncompressed data. (The size of the uncom 1271 uncompressed data. (The size of the uncompressed data must have been saved
1274 previously by the compressor and transmitt 1272 previously by the compressor and transmitted to the decompressor by some
1275 mechanism outside the scope of this compre 1273 mechanism outside the scope of this compression library.) Upon exit, destLen
1276 is the actual size of the uncompressed dat 1274 is the actual size of the uncompressed data.
1277 1275
1278 uncompress returns Z_OK if success, Z_ME 1276 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1279 enough memory, Z_BUF_ERROR if there was no 1277 enough memory, Z_BUF_ERROR if there was not enough room in the output
1280 buffer, or Z_DATA_ERROR if the input data 1278 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In
1281 the case where there is not enough room, u 1279 the case where there is not enough room, uncompress() will fill the output
1282 buffer with the uncompressed data up to th 1280 buffer with the uncompressed data up to that point.
1283 */ 1281 */
1284 1282
1285 ZEXTERN int ZEXPORT uncompress2 OF((Bytef *de 1283 ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest, uLongf *destLen,
1286 const Byt 1284 const Bytef *source, uLong *sourceLen));
1287 /* 1285 /*
1288 Same as uncompress, except that sourceLe 1286 Same as uncompress, except that sourceLen is a pointer, where the
1289 length of the source is *sourceLen. On re 1287 length of the source is *sourceLen. On return, *sourceLen is the number of
1290 source bytes consumed. 1288 source bytes consumed.
1291 */ 1289 */
1292 1290
1293 /* gzip file access f 1291 /* gzip file access functions */
1294 1292
1295 /* 1293 /*
1296 This library supports reading and writin 1294 This library supports reading and writing files in gzip (.gz) format with
1297 an interface similar to that of stdio, usi 1295 an interface similar to that of stdio, using the functions that start with
1298 "gz". The gzip format is different from t 1296 "gz". The gzip format is different from the zlib format. gzip is a gzip
1299 wrapper, documented in RFC 1952, wrapped a 1297 wrapper, documented in RFC 1952, wrapped around a deflate stream.
1300 */ 1298 */
1301 1299
1302 typedef struct gzFile_s *gzFile; /* semi-o 1300 typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
1303 1301
1304 /* 1302 /*
1305 ZEXTERN gzFile ZEXPORT gzopen OF((const char 1303 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
1306 1304
1307 Open the gzip (.gz) file at path for rea << 1305 Opens a gzip (.gz) file for reading or writing. The mode parameter is as
1308 compressing and writing. The mode paramet << 1306 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
1309 but can also include a compression level ( << 1307 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
1310 filtered data as in "wb6f", 'h' for Huffma << 1308 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
1311 'R' for run-length encoding as in "wb1R", << 1309 for fixed code compression as in "wb9F". (See the description of
1312 as in "wb9F". (See the description of def << 1310 deflateInit2 for more information about the strategy parameter.) 'T' will
1313 about the strategy parameter.) 'T' will r << 1311 request transparent writing or appending with no compression and not using
1314 appending with no compression and not usin << 1312 the gzip format.
1315 1313
1316 "a" can be used instead of "w" to reques 1314 "a" can be used instead of "w" to request that the gzip stream that will
1317 be written be appended to the file. "+" w 1315 be written be appended to the file. "+" will result in an error, since
1318 reading and writing to the same gzip file 1316 reading and writing to the same gzip file is not supported. The addition of
1319 "x" when writing will create the file excl 1317 "x" when writing will create the file exclusively, which fails if the file
1320 already exists. On systems that support i 1318 already exists. On systems that support it, the addition of "e" when
1321 reading or writing will set the flag to cl 1319 reading or writing will set the flag to close the file on an execve() call.
1322 1320
1323 These functions, as well as gzip, will r 1321 These functions, as well as gzip, will read and decode a sequence of gzip
1324 streams in a file. The append function of 1322 streams in a file. The append function of gzopen() can be used to create
1325 such a file. (Also see gzflush() for anot 1323 such a file. (Also see gzflush() for another way to do this.) When
1326 appending, gzopen does not test whether th 1324 appending, gzopen does not test whether the file begins with a gzip stream,
1327 nor does it look for the end of the gzip s 1325 nor does it look for the end of the gzip streams to begin appending. gzopen
1328 will simply append a gzip stream to the ex 1326 will simply append a gzip stream to the existing file.
1329 1327
1330 gzopen can be used to read a file which 1328 gzopen can be used to read a file which is not in gzip format; in this
1331 case gzread will directly read from the fi 1329 case gzread will directly read from the file without decompression. When
1332 reading, this will be detected automatical 1330 reading, this will be detected automatically by looking for the magic two-
1333 byte gzip header. 1331 byte gzip header.
1334 1332
1335 gzopen returns NULL if the file could no 1333 gzopen returns NULL if the file could not be opened, if there was
1336 insufficient memory to allocate the gzFile 1334 insufficient memory to allocate the gzFile state, or if an invalid mode was
1337 specified (an 'r', 'w', or 'a' was not pro 1335 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
1338 errno can be checked to determine if the r 1336 errno can be checked to determine if the reason gzopen failed was that the
1339 file could not be opened. 1337 file could not be opened.
1340 */ 1338 */
1341 1339
1342 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, co 1340 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
1343 /* 1341 /*
1344 Associate a gzFile with the file descrip << 1342 gzdopen associates a gzFile with the file descriptor fd. File descriptors
1345 obtained from calls like open, dup, creat, << 1343 are obtained from calls like open, dup, creat, pipe or fileno (if the file
1346 been previously opened with fopen). The m << 1344 has been previously opened with fopen). The mode parameter is as in gzopen.
1347 1345
1348 The next call of gzclose on the returned 1346 The next call of gzclose on the returned gzFile will also close the file
1349 descriptor fd, just like fclose(fdopen(fd, 1347 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
1350 fd. If you want to keep fd open, use fd = 1348 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
1351 mode);. The duplicated descriptor should 1349 mode);. The duplicated descriptor should be saved to avoid a leak, since
1352 gzdopen does not close fd if it fails. If 1350 gzdopen does not close fd if it fails. If you are using fileno() to get the
1353 file descriptor from a FILE *, then you wi 1351 file descriptor from a FILE *, then you will have to use dup() to avoid
1354 double-close()ing the file descriptor. Bo 1352 double-close()ing the file descriptor. Both gzclose() and fclose() will
1355 close the associated file descriptor, so t 1353 close the associated file descriptor, so they need to have different file
1356 descriptors. 1354 descriptors.
1357 1355
1358 gzdopen returns NULL if there was insuff 1356 gzdopen returns NULL if there was insufficient memory to allocate the
1359 gzFile state, if an invalid mode was speci 1357 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
1360 provided, or '+' was provided), or if fd i 1358 provided, or '+' was provided), or if fd is -1. The file descriptor is not
1361 used until the next gz* read, write, seek, 1359 used until the next gz* read, write, seek, or close operation, so gzdopen
1362 will not detect if fd is invalid (unless f 1360 will not detect if fd is invalid (unless fd is -1).
1363 */ 1361 */
1364 1362
1365 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, 1363 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
1366 /* 1364 /*
1367 Set the internal buffer size used by thi << 1365 Set the internal buffer size used by this library's functions. The
1368 size. The default buffer size is 8192 byt << 1366 default buffer size is 8192 bytes. This function must be called after
1369 after gzopen() or gzdopen(), and before an << 1367 gzopen() or gzdopen(), and before any other calls that read or write the
1370 the file. The buffer memory allocation is << 1368 file. The buffer memory allocation is always deferred to the first read or
1371 or write. Three times that size in buffer << 1369 write. Three times that size in buffer space is allocated. A larger buffer
1372 buffer size of, for example, 64K or 128K b << 1370 size of, for example, 64K or 128K bytes will noticeably increase the speed
1373 speed of decompression (reading). << 1371 of decompression (reading).
1374 1372
1375 The new buffer size also affects the max 1373 The new buffer size also affects the maximum length for gzprintf().
1376 1374
1377 gzbuffer() returns 0 on success, or -1 o 1375 gzbuffer() returns 0 on success, or -1 on failure, such as being called
1378 too late. 1376 too late.
1379 */ 1377 */
1380 1378
1381 ZEXTERN int ZEXPORT gzsetparams OF((gzFile fi 1379 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1382 /* 1380 /*
1383 Dynamically update the compression level << 1381 Dynamically update the compression level or strategy. See the description
1384 description of deflateInit2 for the meanin << 1382 of deflateInit2 for the meaning of these parameters. Previously provided
1385 provided data is flushed before applying t << 1383 data is flushed before the parameter change.
1386 1384
1387 gzsetparams returns Z_OK if success, Z_S 1385 gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
1388 opened for writing, Z_ERRNO if there is an 1386 opened for writing, Z_ERRNO if there is an error writing the flushed data,
1389 or Z_MEM_ERROR if there is a memory alloca 1387 or Z_MEM_ERROR if there is a memory allocation error.
1390 */ 1388 */
1391 1389
1392 ZEXTERN int ZEXPORT gzread OF((gzFile file, v 1390 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1393 /* 1391 /*
1394 Read and decompress up to len uncompress << 1392 Reads the given number of uncompressed bytes from the compressed file. If
1395 the input file is not in gzip format, gzre 1393 the input file is not in gzip format, gzread copies the given number of
1396 bytes into the buffer directly from the fi 1394 bytes into the buffer directly from the file.
1397 1395
1398 After reaching the end of a gzip stream 1396 After reaching the end of a gzip stream in the input, gzread will continue
1399 to read, looking for another gzip stream. 1397 to read, looking for another gzip stream. Any number of gzip streams may be
1400 concatenated in the input file, and will a 1398 concatenated in the input file, and will all be decompressed by gzread().
1401 If something other than a gzip stream is e 1399 If something other than a gzip stream is encountered after a gzip stream,
1402 that remaining trailing garbage is ignored 1400 that remaining trailing garbage is ignored (and no error is returned).
1403 1401
1404 gzread can be used to read a gzip file t 1402 gzread can be used to read a gzip file that is being concurrently written.
1405 Upon reaching the end of the input, gzread 1403 Upon reaching the end of the input, gzread will return with the available
1406 data. If the error code returned by gzerr 1404 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
1407 gzclearerr can be used to clear the end of 1405 gzclearerr can be used to clear the end of file indicator in order to permit
1408 gzread to be tried again. Z_OK indicates 1406 gzread to be tried again. Z_OK indicates that a gzip stream was completed
1409 on the last gzread. Z_BUF_ERROR indicates 1407 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the
1410 middle of a gzip stream. Note that gzread 1408 middle of a gzip stream. Note that gzread does not return -1 in the event
1411 of an incomplete gzip stream. This error 1409 of an incomplete gzip stream. This error is deferred until gzclose(), which
1412 will return Z_BUF_ERROR if the last gzread 1410 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
1413 stream. Alternatively, gzerror can be use 1411 stream. Alternatively, gzerror can be used before gzclose to detect this
1414 case. 1412 case.
1415 1413
1416 gzread returns the number of uncompresse 1414 gzread returns the number of uncompressed bytes actually read, less than
1417 len for end of file, or -1 for error. If 1415 len for end of file, or -1 for error. If len is too large to fit in an int,
1418 then nothing is read, -1 is returned, and 1416 then nothing is read, -1 is returned, and the error state is set to
1419 Z_STREAM_ERROR. 1417 Z_STREAM_ERROR.
1420 */ 1418 */
1421 1419
1422 ZEXTERN z_size_t ZEXPORT gzfread OF((voidp bu 1420 ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
1423 gzFile f 1421 gzFile file));
1424 /* 1422 /*
1425 Read and decompress up to nitems items o << 1423 Read up to nitems items of size size from file to buf, otherwise operating
1426 otherwise operating as gzread() does. Thi << 1424 as gzread() does. This duplicates the interface of stdio's fread(), with
1427 stdio's fread(), with size_t request and r << 1425 size_t request and return types. If the library defines size_t, then
1428 defines size_t, then z_size_t is identical << 1426 z_size_t is identical to size_t. If not, then z_size_t is an unsigned
1429 is an unsigned integer type that can conta << 1427 integer type that can contain a pointer.
1430 1428
1431 gzfread() returns the number of full ite 1429 gzfread() returns the number of full items read of size size, or zero if
1432 the end of the file was reached and a full 1430 the end of the file was reached and a full item could not be read, or if
1433 there was an error. gzerror() must be con 1431 there was an error. gzerror() must be consulted if zero is returned in
1434 order to determine if there was an error. 1432 order to determine if there was an error. If the multiplication of size and
1435 nitems overflows, i.e. the product does no 1433 nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
1436 is read, zero is returned, and the error s 1434 is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
1437 1435
1438 In the event that the end of file is rea 1436 In the event that the end of file is reached and only a partial item is
1439 available at the end, i.e. the remaining u 1437 available at the end, i.e. the remaining uncompressed data length is not a
1440 multiple of size, then the final partial i << 1438 multiple of size, then the final partial item is nevetheless read into buf
1441 and the end-of-file flag is set. The leng 1439 and the end-of-file flag is set. The length of the partial item read is not
1442 provided, but could be inferred from the r 1440 provided, but could be inferred from the result of gztell(). This behavior
1443 is the same as the behavior of fread() imp 1441 is the same as the behavior of fread() implementations in common libraries,
1444 but it prevents the direct use of gzfread( 1442 but it prevents the direct use of gzfread() to read a concurrently written
1445 file, resetting and retrying on end-of-fil << 1443 file, reseting and retrying on end-of-file, when size is not 1.
1446 */ 1444 */
1447 1445
1448 ZEXTERN int ZEXPORT gzwrite OF((gzFile file, << 1446 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
>> 1447 voidpc buf, unsigned len));
1449 /* 1448 /*
1450 Compress and write the len uncompressed << 1449 Writes the given number of uncompressed bytes into the compressed file.
1451 returns the number of uncompressed bytes w << 1450 gzwrite returns the number of uncompressed bytes written or 0 in case of
>> 1451 error.
1452 */ 1452 */
1453 1453
1454 ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc 1454 ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size,
1455 z_size_ 1455 z_size_t nitems, gzFile file));
1456 /* 1456 /*
1457 Compress and write nitems items of size << 1457 gzfwrite() writes nitems items of size size from buf to file, duplicating
1458 the interface of stdio's fwrite(), with si 1458 the interface of stdio's fwrite(), with size_t request and return types. If
1459 the library defines size_t, then z_size_t 1459 the library defines size_t, then z_size_t is identical to size_t. If not,
1460 then z_size_t is an unsigned integer type 1460 then z_size_t is an unsigned integer type that can contain a pointer.
1461 1461
1462 gzfwrite() returns the number of full it 1462 gzfwrite() returns the number of full items written of size size, or zero
1463 if there was an error. If the multiplicat 1463 if there was an error. If the multiplication of size and nitems overflows,
1464 i.e. the product does not fit in a z_size_ 1464 i.e. the product does not fit in a z_size_t, then nothing is written, zero
1465 is returned, and the error state is set to 1465 is returned, and the error state is set to Z_STREAM_ERROR.
1466 */ 1466 */
1467 1467
1468 ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile 1468 ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
1469 /* 1469 /*
1470 Convert, format, compress, and write the << 1470 Converts, formats, and writes the arguments to the compressed file under
1471 control of the string format, as in fprint << 1471 control of the format string, as in fprintf. gzprintf returns the number of
1472 uncompressed bytes actually written, or a 1472 uncompressed bytes actually written, or a negative zlib error code in case
1473 of error. The number of uncompressed byte 1473 of error. The number of uncompressed bytes written is limited to 8191, or
1474 one less than the buffer size given to gzb 1474 one less than the buffer size given to gzbuffer(). The caller should assure
1475 that this limit is not exceeded. If it is 1475 that this limit is not exceeded. If it is exceeded, then gzprintf() will
1476 return an error (0) with nothing written. 1476 return an error (0) with nothing written. In this case, there may also be a
1477 buffer overflow with unpredictable consequ 1477 buffer overflow with unpredictable consequences, which is possible only if
1478 zlib was compiled with the insecure functi << 1478 zlib was compiled with the insecure functions sprintf() or vsprintf()
1479 because the secure snprintf() or vsnprintf 1479 because the secure snprintf() or vsnprintf() functions were not available.
1480 This can be determined using zlibCompileFl 1480 This can be determined using zlibCompileFlags().
1481 */ 1481 */
1482 1482
1483 ZEXTERN int ZEXPORT gzputs OF((gzFile file, c 1483 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1484 /* 1484 /*
1485 Compress and write the given null-termin << 1485 Writes the given null-terminated string to the compressed file, excluding
1486 the terminating null character. 1486 the terminating null character.
1487 1487
1488 gzputs returns the number of characters 1488 gzputs returns the number of characters written, or -1 in case of error.
1489 */ 1489 */
1490 1490
1491 ZEXTERN char * ZEXPORT gzgets OF((gzFile file 1491 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1492 /* 1492 /*
1493 Read and decompress bytes from file into << 1493 Reads bytes from the compressed file until len-1 characters are read, or a
1494 read, or until a newline character is read << 1494 newline character is read and transferred to buf, or an end-of-file
1495 end-of-file condition is encountered. If << 1495 condition is encountered. If any characters are read or if len == 1, the
1496 is one, the string is terminated with a nu << 1496 string is terminated with a null character. If no characters are read due
1497 are read due to an end-of-file or len is l << 1497 to an end-of-file or len < 1, then the buffer is left untouched.
1498 left untouched. <<
1499 1498
1500 gzgets returns buf which is a null-termi 1499 gzgets returns buf which is a null-terminated string, or it returns NULL
1501 for end-of-file or in case of error. If t 1500 for end-of-file or in case of error. If there was an error, the contents at
1502 buf are indeterminate. 1501 buf are indeterminate.
1503 */ 1502 */
1504 1503
1505 ZEXTERN int ZEXPORT gzputc OF((gzFile file, i 1504 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1506 /* 1505 /*
1507 Compress and write c, converted to an un << 1506 Writes c, converted to an unsigned char, into the compressed file. gzputc
1508 returns the value that was written, or -1 1507 returns the value that was written, or -1 in case of error.
1509 */ 1508 */
1510 1509
1511 ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); 1510 ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1512 /* 1511 /*
1513 Read and decompress one byte from file. << 1512 Reads one byte from the compressed file. gzgetc returns this byte or -1
1514 in case of end of file or error. This is 1513 in case of end of file or error. This is implemented as a macro for speed.
1515 As such, it does not do all of the checkin 1514 As such, it does not do all of the checking the other functions do. I.e.
1516 it does not check to see if file is NULL, 1515 it does not check to see if file is NULL, nor whether the structure file
1517 points to has been clobbered or not. 1516 points to has been clobbered or not.
1518 */ 1517 */
1519 1518
1520 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFil 1519 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1521 /* 1520 /*
1522 Push c back onto the stream for file to << 1521 Push one character back onto the stream to be read as the first character
1523 the next read. At least one character of << 1522 on the next read. At least one character of push-back is allowed.
1524 gzungetc() returns the character pushed, o 1523 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
1525 fail if c is -1, and may fail if a charact 1524 fail if c is -1, and may fail if a character has been pushed but not read
1526 yet. If gzungetc is used immediately afte 1525 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
1527 output buffer size of pushed characters is 1526 output buffer size of pushed characters is allowed. (See gzbuffer above.)
1528 The pushed character will be discarded if 1527 The pushed character will be discarded if the stream is repositioned with
1529 gzseek() or gzrewind(). 1528 gzseek() or gzrewind().
1530 */ 1529 */
1531 1530
1532 ZEXTERN int ZEXPORT gzflush OF((gzFile file, 1531 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1533 /* 1532 /*
1534 Flush all pending output to file. The p << 1533 Flushes all pending output into the compressed file. The parameter flush
1535 deflate() function. The return value is t << 1534 is as in the deflate() function. The return value is the zlib error number
1536 gzerror below). gzflush is only permitted << 1535 (see function gzerror below). gzflush is only permitted when writing.
1537 1536
1538 If the flush parameter is Z_FINISH, the 1537 If the flush parameter is Z_FINISH, the remaining data is written and the
1539 gzip stream is completed in the output. I 1538 gzip stream is completed in the output. If gzwrite() is called again, a new
1540 gzip stream will be started in the output. 1539 gzip stream will be started in the output. gzread() is able to read such
1541 concatenated gzip streams. 1540 concatenated gzip streams.
1542 1541
1543 gzflush should be called only when stric 1542 gzflush should be called only when strictly necessary because it will
1544 degrade compression if called too often. 1543 degrade compression if called too often.
1545 */ 1544 */
1546 1545
1547 /* 1546 /*
1548 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile fil 1547 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
1549 z_off_t of 1548 z_off_t offset, int whence));
1550 1549
1551 Set the starting position to offset rela << 1550 Sets the starting position for the next gzread or gzwrite on the given
1552 or gzwrite on file. The offset represents << 1551 compressed file. The offset represents a number of bytes in the
1553 uncompressed data stream. The whence para 1552 uncompressed data stream. The whence parameter is defined as in lseek(2);
1554 the value SEEK_END is not supported. 1553 the value SEEK_END is not supported.
1555 1554
1556 If the file is opened for reading, this 1555 If the file is opened for reading, this function is emulated but can be
1557 extremely slow. If the file is opened for 1556 extremely slow. If the file is opened for writing, only forward seeks are
1558 supported; gzseek then compresses a sequen 1557 supported; gzseek then compresses a sequence of zeroes up to the new
1559 starting position. 1558 starting position.
1560 1559
1561 gzseek returns the resulting offset loca 1560 gzseek returns the resulting offset location as measured in bytes from
1562 the beginning of the uncompressed stream, 1561 the beginning of the uncompressed stream, or -1 in case of error, in
1563 particular if the file is opened for writi 1562 particular if the file is opened for writing and the new starting position
1564 would be before the current position. 1563 would be before the current position.
1565 */ 1564 */
1566 1565
1567 ZEXTERN int ZEXPORT gzrewind OF((gzFile fi 1566 ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
1568 /* 1567 /*
1569 Rewind file. This function is supported << 1568 Rewinds the given file. This function is supported only for reading.
1570 1569
1571 gzrewind(file) is equivalent to (int)gzs << 1570 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1572 */ 1571 */
1573 1572
1574 /* 1573 /*
1575 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile 1574 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1576 1575
1577 Return the starting position for the nex << 1576 Returns the starting position for the next gzread or gzwrite on the given
1578 This position represents a number of bytes << 1577 compressed file. This position represents a number of bytes in the
1579 and is zero when starting, even if appendi << 1578 uncompressed data stream, and is zero when starting, even if appending or
1580 the middle of a file using gzdopen(). << 1579 reading a gzip stream from the middle of a file using gzdopen().
1581 1580
1582 gztell(file) is equivalent to gzseek(fil 1581 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1583 */ 1582 */
1584 1583
1585 /* 1584 /*
1586 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile f 1585 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
1587 1586
1588 Return the current compressed (actual) r << 1587 Returns the current offset in the file being read or written. This offset
1589 offset includes the count of bytes that pr << 1588 includes the count of bytes that precede the gzip stream, for example when
1590 when appending or when using gzdopen() for << 1589 appending or when using gzdopen() for reading. When reading, the offset
1591 offset does not include as yet unused buff << 1590 does not include as yet unused buffered input. This information can be used
1592 be used for a progress indicator. On erro << 1591 for a progress indicator. On error, gzoffset() returns -1.
1593 */ 1592 */
1594 1593
1595 ZEXTERN int ZEXPORT gzeof OF((gzFile file)); 1594 ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1596 /* 1595 /*
1597 Return true (1) if the end-of-file indic << 1596 Returns true (1) if the end-of-file indicator has been set while reading,
1598 reading, false (0) otherwise. Note that t << 1597 false (0) otherwise. Note that the end-of-file indicator is set only if the
1599 only if the read tried to go past the end << 1598 read tried to go past the end of the input, but came up short. Therefore,
1600 Therefore, just like feof(), gzeof() may r << 1599 just like feof(), gzeof() may return false even if there is no more data to
1601 more data to read, in the event that the l << 1600 read, in the event that the last read request was for the exact number of
1602 number of bytes remaining in the input fil << 1601 bytes remaining in the input file. This will happen if the input file size
1603 file size is an exact multiple of the buff << 1602 is an exact multiple of the buffer size.
1604 1603
1605 If gzeof() returns true, then the read f 1604 If gzeof() returns true, then the read functions will return no more data,
1606 unless the end-of-file indicator is reset 1605 unless the end-of-file indicator is reset by gzclearerr() and the input file
1607 has grown since the previous end of file w 1606 has grown since the previous end of file was detected.
1608 */ 1607 */
1609 1608
1610 ZEXTERN int ZEXPORT gzdirect OF((gzFile file) 1609 ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1611 /* 1610 /*
1612 Return true (1) if file is being copied << 1611 Returns true (1) if file is being copied directly while reading, or false
1613 (0) if file is a gzip stream being decompr 1612 (0) if file is a gzip stream being decompressed.
1614 1613
1615 If the input file is empty, gzdirect() w 1614 If the input file is empty, gzdirect() will return true, since the input
1616 does not contain a gzip stream. 1615 does not contain a gzip stream.
1617 1616
1618 If gzdirect() is used immediately after 1617 If gzdirect() is used immediately after gzopen() or gzdopen() it will
1619 cause buffers to be allocated to allow rea 1618 cause buffers to be allocated to allow reading the file to determine if it
1620 is a gzip file. Therefore if gzbuffer() i 1619 is a gzip file. Therefore if gzbuffer() is used, it should be called before
1621 gzdirect(). 1620 gzdirect().
1622 1621
1623 When writing, gzdirect() returns true (1 1622 When writing, gzdirect() returns true (1) if transparent writing was
1624 requested ("wT" for the gzopen() mode), or 1623 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note:
1625 gzdirect() is not needed when writing. Tr 1624 gzdirect() is not needed when writing. Transparent writing must be
1626 explicitly requested, so the application a 1625 explicitly requested, so the application already knows the answer. When
1627 linking statically, using gzdirect() will 1626 linking statically, using gzdirect() will include all of the zlib code for
1628 gzip file reading and decompression, which 1627 gzip file reading and decompression, which may not be desired.)
1629 */ 1628 */
1630 1629
1631 ZEXTERN int ZEXPORT gzclose OF((gzFile fil 1630 ZEXTERN int ZEXPORT gzclose OF((gzFile file));
1632 /* 1631 /*
1633 Flush all pending output for file, if ne << 1632 Flushes all pending output if necessary, closes the compressed file and
1634 deallocate the (de)compression state. Not << 1633 deallocates the (de)compression state. Note that once file is closed, you
1635 cannot call gzerror with file, since its s 1634 cannot call gzerror with file, since its structures have been deallocated.
1636 gzclose must not be called more than once 1635 gzclose must not be called more than once on the same file, just as free
1637 must not be called more than once on the s 1636 must not be called more than once on the same allocation.
1638 1637
1639 gzclose will return Z_STREAM_ERROR if fi 1638 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
1640 file operation error, Z_MEM_ERROR if out o 1639 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
1641 last read ended in the middle of a gzip st 1640 last read ended in the middle of a gzip stream, or Z_OK on success.
1642 */ 1641 */
1643 1642
1644 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file 1643 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
1645 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file 1644 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
1646 /* 1645 /*
1647 Same as gzclose(), but gzclose_r() is on 1646 Same as gzclose(), but gzclose_r() is only for use when reading, and
1648 gzclose_w() is only for use when writing o 1647 gzclose_w() is only for use when writing or appending. The advantage to
1649 using these instead of gzclose() is that t 1648 using these instead of gzclose() is that they avoid linking in zlib
1650 compression or decompression code that is 1649 compression or decompression code that is not used when only reading or only
1651 writing respectively. If gzclose() is use 1650 writing respectively. If gzclose() is used, then both compression and
1652 decompression code will be included the ap 1651 decompression code will be included the application when linking to a static
1653 zlib library. 1652 zlib library.
1654 */ 1653 */
1655 1654
1656 ZEXTERN const char * ZEXPORT gzerror OF((gzFi 1655 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
1657 /* 1656 /*
1658 Return the error message for the last er << 1657 Returns the error message for the last error which occurred on the given
1659 errnum is set to zlib error number. If an << 1658 compressed file. errnum is set to zlib error number. If an error occurred
1660 and not in the compression library, errnum << 1659 in the file system and not in the compression library, errnum is set to
1661 application may consult errno to get the e << 1660 Z_ERRNO and the application may consult errno to get the exact error code.
1662 1661
1663 The application must not modify the retu 1662 The application must not modify the returned string. Future calls to
1664 this function may invalidate the previousl 1663 this function may invalidate the previously returned string. If file is
1665 closed, then the string previously returne 1664 closed, then the string previously returned by gzerror will no longer be
1666 available. 1665 available.
1667 1666
1668 gzerror() should be used to distinguish 1667 gzerror() should be used to distinguish errors from end-of-file for those
1669 functions above that do not distinguish th 1668 functions above that do not distinguish those cases in their return values.
1670 */ 1669 */
1671 1670
1672 ZEXTERN void ZEXPORT gzclearerr OF((gzFile fi 1671 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1673 /* 1672 /*
1674 Clear the error and end-of-file flags fo << 1673 Clears the error and end-of-file flags for file. This is analogous to the
1675 clearerr() function in stdio. This is use 1674 clearerr() function in stdio. This is useful for continuing to read a gzip
1676 file that is being written concurrently. 1675 file that is being written concurrently.
1677 */ 1676 */
1678 1677
1679 #endif /* !Z_SOLO */ 1678 #endif /* !Z_SOLO */
1680 1679
1681 /* checksum functions 1680 /* checksum functions */
1682 1681
1683 /* 1682 /*
1684 These functions are not related to compr 1683 These functions are not related to compression but are exported
1685 anyway because they might be useful in app 1684 anyway because they might be useful in applications using the compression
1686 library. 1685 library.
1687 */ 1686 */
1688 1687
1689 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler 1688 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
1690 /* 1689 /*
1691 Update a running Adler-32 checksum with 1690 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1692 return the updated checksum. An Adler-32 v << 1691 return the updated checksum. If buf is Z_NULL, this function returns the
1693 unsigned integer. If buf is Z_NULL, this f << 1692 required initial value for the checksum.
1694 initial value for the checksum. <<
1695 1693
1696 An Adler-32 checksum is almost as reliab 1694 An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
1697 much faster. 1695 much faster.
1698 1696
1699 Usage example: 1697 Usage example:
1700 1698
1701 uLong adler = adler32(0L, Z_NULL, 0); 1699 uLong adler = adler32(0L, Z_NULL, 0);
1702 1700
1703 while (read_buffer(buffer, length) != EO 1701 while (read_buffer(buffer, length) != EOF) {
1704 adler = adler32(adler, buffer, length) 1702 adler = adler32(adler, buffer, length);
1705 } 1703 }
1706 if (adler != original_adler) error(); 1704 if (adler != original_adler) error();
1707 */ 1705 */
1708 1706
1709 ZEXTERN uLong ZEXPORT adler32_z OF((uLong adl 1707 ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf,
1710 z_size_t 1708 z_size_t len));
1711 /* 1709 /*
1712 Same as adler32(), but with a size_t len 1710 Same as adler32(), but with a size_t length.
1713 */ 1711 */
1714 1712
1715 /* 1713 /*
1716 ZEXTERN uLong ZEXPORT adler32_combine OF((uLo 1714 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
1717 z_o 1715 z_off_t len2));
1718 1716
1719 Combine two Adler-32 checksums into one. 1717 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
1720 and seq2 with lengths len1 and len2, Adler 1718 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1721 each, adler1 and adler2. adler32_combine( 1719 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
1722 seq1 and seq2 concatenated, requiring only 1720 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note
1723 that the z_off_t type (like off_t) is a si 1721 that the z_off_t type (like off_t) is a signed integer. If len2 is
1724 negative, the result has no meaning or uti 1722 negative, the result has no meaning or utility.
1725 */ 1723 */
1726 1724
1727 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, co << 1725 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
1728 /* 1726 /*
1729 Update a running CRC-32 with the bytes b 1727 Update a running CRC-32 with the bytes buf[0..len-1] and return the
1730 updated CRC-32. A CRC-32 value is in the r << 1728 updated CRC-32. If buf is Z_NULL, this function returns the required
1731 If buf is Z_NULL, this function returns th << 1729 initial value for the crc. Pre- and post-conditioning (one's complement) is
1732 crc. Pre- and post-conditioning (one's com << 1730 performed within this function so it shouldn't be done by the application.
1733 function so it shouldn't be done by the ap <<
1734 1731
1735 Usage example: 1732 Usage example:
1736 1733
1737 uLong crc = crc32(0L, Z_NULL, 0); 1734 uLong crc = crc32(0L, Z_NULL, 0);
1738 1735
1739 while (read_buffer(buffer, length) != EO 1736 while (read_buffer(buffer, length) != EOF) {
1740 crc = crc32(crc, buffer, length); 1737 crc = crc32(crc, buffer, length);
1741 } 1738 }
1742 if (crc != original_crc) error(); 1739 if (crc != original_crc) error();
1743 */ 1740 */
1744 1741
1745 ZEXTERN uLong ZEXPORT crc32_z OF((uLong crc, << 1742 ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf,
1746 z_size_t le 1743 z_size_t len));
1747 /* 1744 /*
1748 Same as crc32(), but with a size_t lengt 1745 Same as crc32(), but with a size_t length.
1749 */ 1746 */
1750 1747
1751 /* 1748 /*
1752 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong 1749 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
1753 1750
1754 Combine two CRC-32 check values into one 1751 Combine two CRC-32 check values into one. For two sequences of bytes,
1755 seq1 and seq2 with lengths len1 and len2, 1752 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1756 calculated for each, crc1 and crc2. crc32 1753 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1757 check value of seq1 and seq2 concatenated, 1754 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1758 len2. 1755 len2.
1759 */ 1756 */
1760 1757
1761 /* <<
1762 ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z <<
1763 <<
1764 Return the operator corresponding to len <<
1765 crc32_combine_op(). <<
1766 */ <<
1767 <<
1768 ZEXTERN uLong ZEXPORT crc32_combine_op OF((uL <<
1769 /* <<
1770 Give the same result as crc32_combine(), <<
1771 is generated from len2 by crc32_combine_ge <<
1772 crc32_combine() if the generated op is use <<
1773 */ <<
1774 <<
1775 1758
1776 /* various hacks, don 1759 /* various hacks, don't look :) */
1777 1760
1778 /* deflateInit and inflateInit are macros to 1761 /* deflateInit and inflateInit are macros to allow checking the zlib version
1779 * and the compiler's view of z_stream: 1762 * and the compiler's view of z_stream:
1780 */ 1763 */
1781 ZEXTERN int ZEXPORT deflateInit_ OF((z_stream 1764 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1782 const ch 1765 const char *version, int stream_size));
1783 ZEXTERN int ZEXPORT inflateInit_ OF((z_stream 1766 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
1784 const ch 1767 const char *version, int stream_size));
1785 ZEXTERN int ZEXPORT deflateInit2_ OF((z_strea 1768 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1786 int win 1769 int windowBits, int memLevel,
1787 int str 1770 int strategy, const char *version,
1788 int str 1771 int stream_size));
1789 ZEXTERN int ZEXPORT inflateInit2_ OF((z_strea 1772 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
1790 const c 1773 const char *version, int stream_size));
1791 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_st 1774 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
1792 unsi 1775 unsigned char FAR *window,
1793 cons 1776 const char *version,
1794 int 1777 int stream_size));
1795 #ifdef Z_PREFIX_SET 1778 #ifdef Z_PREFIX_SET
1796 # define z_deflateInit(strm, level) \ 1779 # define z_deflateInit(strm, level) \
1797 deflateInit_((strm), (level), ZLIB_ 1780 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1798 # define z_inflateInit(strm) \ 1781 # define z_inflateInit(strm) \
1799 inflateInit_((strm), ZLIB_VERSION, 1782 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1800 # define z_deflateInit2(strm, level, method, 1783 # define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1801 deflateInit2_((strm),(level),(metho 1784 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1802 (strategy), ZLIB_VERS 1785 (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1803 # define z_inflateInit2(strm, windowBits) \ 1786 # define z_inflateInit2(strm, windowBits) \
1804 inflateInit2_((strm), (windowBits), 1787 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1805 (int)sizeof(z_stream) 1788 (int)sizeof(z_stream))
1806 # define z_inflateBackInit(strm, windowBits, 1789 # define z_inflateBackInit(strm, windowBits, window) \
1807 inflateBackInit_((strm), (windowBit 1790 inflateBackInit_((strm), (windowBits), (window), \
1808 ZLIB_VERSION, (int 1791 ZLIB_VERSION, (int)sizeof(z_stream))
1809 #else 1792 #else
1810 # define deflateInit(strm, level) \ 1793 # define deflateInit(strm, level) \
1811 deflateInit_((strm), (level), ZLIB_ 1794 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1812 # define inflateInit(strm) \ 1795 # define inflateInit(strm) \
1813 inflateInit_((strm), ZLIB_VERSION, 1796 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
1814 # define deflateInit2(strm, level, method, w 1797 # define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1815 deflateInit2_((strm),(level),(metho 1798 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1816 (strategy), ZLIB_VERS 1799 (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
1817 # define inflateInit2(strm, windowBits) \ 1800 # define inflateInit2(strm, windowBits) \
1818 inflateInit2_((strm), (windowBits), 1801 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
1819 (int)sizeof(z_stream) 1802 (int)sizeof(z_stream))
1820 # define inflateBackInit(strm, windowBits, w 1803 # define inflateBackInit(strm, windowBits, window) \
1821 inflateBackInit_((strm), (windowBit 1804 inflateBackInit_((strm), (windowBits), (window), \
1822 ZLIB_VERSION, (int 1805 ZLIB_VERSION, (int)sizeof(z_stream))
1823 #endif 1806 #endif
1824 1807
1825 #ifndef Z_SOLO 1808 #ifndef Z_SOLO
1826 1809
1827 /* gzgetc() macro and its supporting function 1810 /* gzgetc() macro and its supporting function and exposed data structure. Note
1828 * that the real internal state is much large 1811 * that the real internal state is much larger than the exposed structure.
1829 * This abbreviated structure exposes just en 1812 * This abbreviated structure exposes just enough for the gzgetc() macro. The
1830 * user should not mess with these exposed el 1813 * user should not mess with these exposed elements, since their names or
1831 * behavior could change in the future, perha 1814 * behavior could change in the future, perhaps even capriciously. They can
1832 * only be used by the gzgetc() macro. You h 1815 * only be used by the gzgetc() macro. You have been warned.
1833 */ 1816 */
1834 struct gzFile_s { 1817 struct gzFile_s {
1835 unsigned have; 1818 unsigned have;
1836 unsigned char *next; 1819 unsigned char *next;
1837 z_off64_t pos; 1820 z_off64_t pos;
1838 }; 1821 };
1839 ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)) 1822 ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */
1840 #ifdef Z_PREFIX_SET 1823 #ifdef Z_PREFIX_SET
1841 # undef z_gzgetc 1824 # undef z_gzgetc
1842 # define z_gzgetc(g) \ 1825 # define z_gzgetc(g) \
1843 ((g)->have ? ((g)->have--, (g)->pos 1826 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1844 #else 1827 #else
1845 # define gzgetc(g) \ 1828 # define gzgetc(g) \
1846 ((g)->have ? ((g)->have--, (g)->pos 1829 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1847 #endif 1830 #endif
1848 1831
1849 /* provide 64-bit offset functions if _LARGEF 1832 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1850 * change the regular functions to 64 bits if 1833 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
1851 * both are true, the application gets the *6 1834 * both are true, the application gets the *64 functions, and the regular
1852 * functions are changed to 64 bits) -- in ca 1835 * functions are changed to 64 bits) -- in case these are set on systems
1853 * without large file support, _LFS64_LARGEFI 1836 * without large file support, _LFS64_LARGEFILE must also be true
1854 */ 1837 */
1855 #ifdef Z_LARGE64 1838 #ifdef Z_LARGE64
1856 ZEXTERN gzFile ZEXPORT gzopen64 OF((const 1839 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1857 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzF 1840 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
1858 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzF 1841 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
1859 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((g 1842 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
1860 ZEXTERN uLong ZEXPORT adler32_combine64 OF 1843 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
1861 ZEXTERN uLong ZEXPORT crc32_combine64 OF(( 1844 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
1862 ZEXTERN uLong ZEXPORT crc32_combine_gen64 <<
1863 #endif 1845 #endif
1864 1846
1865 #if !defined(ZLIB_INTERNAL) && defined(Z_WANT 1847 #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
1866 # ifdef Z_PREFIX_SET 1848 # ifdef Z_PREFIX_SET
1867 # define z_gzopen z_gzopen64 1849 # define z_gzopen z_gzopen64
1868 # define z_gzseek z_gzseek64 1850 # define z_gzseek z_gzseek64
1869 # define z_gztell z_gztell64 1851 # define z_gztell z_gztell64
1870 # define z_gzoffset z_gzoffset64 1852 # define z_gzoffset z_gzoffset64
1871 # define z_adler32_combine z_adler32_combi 1853 # define z_adler32_combine z_adler32_combine64
1872 # define z_crc32_combine z_crc32_combine64 1854 # define z_crc32_combine z_crc32_combine64
1873 # define z_crc32_combine_gen z_crc32_combi <<
1874 # else 1855 # else
1875 # define gzopen gzopen64 1856 # define gzopen gzopen64
1876 # define gzseek gzseek64 1857 # define gzseek gzseek64
1877 # define gztell gztell64 1858 # define gztell gztell64
1878 # define gzoffset gzoffset64 1859 # define gzoffset gzoffset64
1879 # define adler32_combine adler32_combine64 1860 # define adler32_combine adler32_combine64
1880 # define crc32_combine crc32_combine64 1861 # define crc32_combine crc32_combine64
1881 # define crc32_combine_gen crc32_combine_g <<
1882 # endif 1862 # endif
1883 # ifndef Z_LARGE64 1863 # ifndef Z_LARGE64
1884 ZEXTERN gzFile ZEXPORT gzopen64 OF((cons 1864 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
1885 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzF 1865 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
1886 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzF 1866 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
1887 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((g 1867 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
1888 ZEXTERN uLong ZEXPORT adler32_combine64 1868 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
1889 ZEXTERN uLong ZEXPORT crc32_combine64 OF 1869 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
1890 ZEXTERN uLong ZEXPORT crc32_combine_gen6 <<
1891 # endif 1870 # endif
1892 #else 1871 #else
1893 ZEXTERN gzFile ZEXPORT gzopen OF((const ch 1872 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
1894 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, 1873 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
1895 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile) 1874 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
1896 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFil 1875 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
1897 ZEXTERN uLong ZEXPORT adler32_combine OF(( 1876 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1898 ZEXTERN uLong ZEXPORT crc32_combine OF((uL 1877 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1899 ZEXTERN uLong ZEXPORT crc32_combine_gen OF <<
1900 #endif 1878 #endif
1901 1879
1902 #else /* Z_SOLO */ 1880 #else /* Z_SOLO */
1903 1881
1904 ZEXTERN uLong ZEXPORT adler32_combine OF(( 1882 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
1905 ZEXTERN uLong ZEXPORT crc32_combine OF((uL 1883 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
1906 ZEXTERN uLong ZEXPORT crc32_combine_gen OF <<
1907 1884
1908 #endif /* !Z_SOLO */ 1885 #endif /* !Z_SOLO */
1909 1886
1910 /* undocumented functions */ 1887 /* undocumented functions */
1911 ZEXTERN const char * ZEXPORT zError 1888 ZEXTERN const char * ZEXPORT zError OF((int));
1912 ZEXTERN int ZEXPORT inflateSyncPoi 1889 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
1913 ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_t 1890 ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void));
1914 ZEXTERN int ZEXPORT inflateUndermi 1891 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
1915 ZEXTERN int ZEXPORT inflateValidat 1892 ZEXTERN int ZEXPORT inflateValidate OF((z_streamp, int));
1916 ZEXTERN unsigned long ZEXPORT inflateCodesUs << 1893 ZEXTERN unsigned long ZEXPORT inflateCodesUsed OF ((z_streamp));
1917 ZEXTERN int ZEXPORT inflateResetKe 1894 ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp));
1918 ZEXTERN int ZEXPORT deflateResetKe 1895 ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp));
1919 #if defined(_WIN32) && !defined(Z_SOLO) << 1896 #if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(Z_SOLO)
1920 ZEXTERN gzFile ZEXPORT gzopen_w OF((c 1897 ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path,
1921 c 1898 const char *mode));
1922 #endif 1899 #endif
1923 #if defined(STDC) || defined(Z_HAVE_STDARG_H) 1900 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
1924 # ifndef Z_SOLO 1901 # ifndef Z_SOLO
1925 ZEXTERN int ZEXPORTVA gzvprintf Z_ 1902 ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file,
1926 1903 const char *format,
1927 1904 va_list va));
1928 # endif 1905 # endif
1929 #endif 1906 #endif
1930 1907
1931 #ifdef __cplusplus 1908 #ifdef __cplusplus
1932 } 1909 }
1933 #endif 1910 #endif
1934 1911
1935 #endif /* ZLIB_H */ 1912 #endif /* ZLIB_H */
1936 1913