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Applied downs' lphobos update
author Tomas Lindquist Olsen <tomas.l.olsen@gmail.com>
date Mon, 04 Aug 2008 19:28:49 +0200
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1 /* zlib.d: modified from zlib.h by Walter Bright */
2 /* NOTE: This file has been patched from the original DMD distribution to
3 work with the GDC compiler.
4
5 Modified by David Friedman, February 2007
6 */
7
8 module etc.c.zlib;
9
10 /* zlib.h -- interface of the 'zlib' general purpose compression library
11 version 1.2.1, November 17th, 2003
12
13 Copyright (C) 1995-2003 Jean-loup Gailly and Mark Adler
14
15 This software is provided 'as-is', without any express or implied
16 warranty. In no event will the authors be held liable for any damages
17 arising from the use of this software.
18
19 Permission is granted to anyone to use this software for any purpose,
20 including commercial applications, and to alter it and redistribute it
21 freely, subject to the following restrictions:
22
23 1. The origin of this software must not be misrepresented; you must not
24 claim that you wrote the original software. If you use this software
25 in a product, an acknowledgment in the product documentation would be
26 appreciated but is not required.
27 2. Altered source versions must be plainly marked as such, and must not be
28 misrepresented as being the original software.
29 3. This notice may not be removed or altered from any source distribution.
30
31 Jean-loup Gailly Mark Adler
32 jloup@gzip.org madler@alumni.caltech.edu
33
34
35 The data format used by the zlib library is described by RFCs (Request for
36 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
37 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
38 */
39
40 private import std.stdint;
41
42 extern (C):
43 alias uint Culong_t;
44 alias int Clong_t;
45
46 char[] ZLIB_VERSION = "1.2.1";
47
48 /*
49 The 'zlib' compression library provides in-memory compression and
50 decompression functions, including integrity checks of the uncompressed
51 data. This version of the library supports only one compression method
52 (deflation) but other algorithms will be added later and will have the same
53 stream interface.
54
55 Compression can be done in a single step if the buffers are large
56 enough (for example if an input file is mmap'ed), or can be done by
57 repeated calls of the compression function. In the latter case, the
58 application must provide more input and/or consume the output
59 (providing more output space) before each call.
60
61 The compressed data format used by the in-memory functions is the zlib
62 format, which is a zlib wrapper documented in RFC 1950, wrapped around a
63 deflate stream, which is itself documented in RFC 1951.
64
65 The library also supports reading and writing files in gzip (.gz) format
66 with an interface similar to that of stdio using the functions that start
67 with "gz". The gzip format is different from the zlib format. gzip is a
68 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
69
70 The zlib format was designed to be compact and fast for use in memory
71 and on communications channels. The gzip format was designed for single-
72 file compression on file systems, has a larger header than zlib to maintain
73 directory information, and uses a different, slower check method than zlib.
74
75 This library does not provide any functions to write gzip files in memory.
76 However such functions could be easily written using zlib's deflate function,
77 the documentation in the gzip RFC, and the examples in gzio.c.
78
79 The library does not install any signal handler. The decoder checks
80 the consistency of the compressed data, so the library should never
81 crash even in case of corrupted input.
82 */
83
84 alias void* (*alloc_func) (void* opaque, uint items, uint size);
85 alias void (*free_func) (void* opaque, void* address);
86
87 struct z_stream
88 {
89 ubyte *next_in; /* next input byte */
90 uint avail_in; /* number of bytes available at next_in */
91 Culong_t total_in; /* total nb of input bytes read so far */
92
93 ubyte *next_out; /* next output byte should be put there */
94 uint avail_out; /* remaining free space at next_out */
95 Culong_t total_out; /* total nb of bytes output so far */
96
97 char *msg; /* last error message, NULL if no error */
98 void* state; /* not visible by applications */
99
100 alloc_func zalloc; /* used to allocate the internal state */
101 free_func zfree; /* used to free the internal state */
102 void* opaque; /* private data object passed to zalloc and zfree */
103
104 int data_type; /* best guess about the data type: ascii or binary */
105 Culong_t adler; /* adler32 value of the uncompressed data */
106 Culong_t reserved; /* reserved for future use */
107 }
108
109 alias z_stream* z_streamp;
110
111 /*
112 The application must update next_in and avail_in when avail_in has
113 dropped to zero. It must update next_out and avail_out when avail_out
114 has dropped to zero. The application must initialize zalloc, zfree and
115 opaque before calling the init function. All other fields are set by the
116 compression library and must not be updated by the application.
117
118 The opaque value provided by the application will be passed as the first
119 parameter for calls of zalloc and zfree. This can be useful for custom
120 memory management. The compression library attaches no meaning to the
121 opaque value.
122
123 zalloc must return Z_NULL if there is not enough memory for the object.
124 If zlib is used in a multi-threaded application, zalloc and zfree must be
125 thread safe.
126
127 On 16-bit systems, the functions zalloc and zfree must be able to allocate
128 exactly 65536 bytes, but will not be required to allocate more than this
129 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
130 pointers returned by zalloc for objects of exactly 65536 bytes *must*
131 have their offset normalized to zero. The default allocation function
132 provided by this library ensures this (see zutil.c). To reduce memory
133 requirements and avoid any allocation of 64K objects, at the expense of
134 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
135
136 The fields total_in and total_out can be used for statistics or
137 progress reports. After compression, total_in holds the total size of
138 the uncompressed data and may be saved for use in the decompressor
139 (particularly if the decompressor wants to decompress everything in
140 a single step).
141 */
142
143 /* constants */
144
145 enum
146 {
147 Z_NO_FLUSH = 0,
148 Z_PARTIAL_FLUSH = 1, /* will be removed, use Z_SYNC_FLUSH instead */
149 Z_SYNC_FLUSH = 2,
150 Z_FULL_FLUSH = 3,
151 Z_FINISH = 4,
152 Z_BLOCK = 5
153 }
154 /* Allowed flush values; see deflate() and inflate() below for details */
155
156 enum
157 {
158 Z_OK = 0,
159 Z_STREAM_END = 1,
160 Z_NEED_DICT = 2,
161 Z_ERRNO = -1,
162 Z_STREAM_ERROR = -2,
163 Z_DATA_ERROR = -3,
164 Z_MEM_ERROR = -4,
165 Z_BUF_ERROR = -5,
166 Z_VERSION_ERROR = -6,
167 }
168 /* Return codes for the compression/decompression functions. Negative
169 * values are errors, positive values are used for special but normal events.
170 */
171
172 enum
173 {
174 Z_NO_COMPRESSION = 0,
175 Z_BEST_SPEED = 1,
176 Z_BEST_COMPRESSION = 9,
177 Z_DEFAULT_COMPRESSION = -1,
178 }
179 /* compression levels */
180
181 enum
182 {
183 Z_FILTERED = 1,
184 Z_HUFFMAN_ONLY = 2,
185 Z_RLE = 3,
186 Z_DEFAULT_STRATEGY = 0,
187 }
188 /* compression strategy; see deflateInit2() below for details */
189
190 enum
191 {
192 Z_BINARY = 0,
193 Z_ASCII = 1,
194 Z_UNKNOWN = 2,
195 }
196 /* Possible values of the data_type field (though see inflate()) */
197
198 enum
199 {
200 Z_DEFLATED = 8,
201 }
202 /* The deflate compression method (the only one supported in this version) */
203
204 const int Z_NULL = 0; /* for initializing zalloc, zfree, opaque */
205
206 /* basic functions */
207
208 char* zlibVersion();
209 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
210 If the first character differs, the library code actually used is
211 not compatible with the zlib.h header file used by the application.
212 This check is automatically made by deflateInit and inflateInit.
213 */
214
215 int deflateInit(z_streamp strm, int level)
216 {
217 return deflateInit_(strm, level, ZLIB_VERSION.ptr, z_stream.sizeof);
218 }
219 /*
220 Initializes the internal stream state for compression. The fields
221 zalloc, zfree and opaque must be initialized before by the caller.
222 If zalloc and zfree are set to Z_NULL, deflateInit updates them to
223 use default allocation functions.
224
225 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
226 1 gives best speed, 9 gives best compression, 0 gives no compression at
227 all (the input data is simply copied a block at a time).
228 Z_DEFAULT_COMPRESSION requests a default compromise between speed and
229 compression (currently equivalent to level 6).
230
231 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
232 enough memory, Z_STREAM_ERROR if level is not a valid compression level,
233 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
234 with the version assumed by the caller (ZLIB_VERSION).
235 msg is set to null if there is no error message. deflateInit does not
236 perform any compression: this will be done by deflate().
237 */
238
239
240 int deflate(z_streamp strm, int flush);
241 /*
242 deflate compresses as much data as possible, and stops when the input
243 buffer becomes empty or the output buffer becomes full. It may introduce some
244 output latency (reading input without producing any output) except when
245 forced to flush.
246
247 The detailed semantics are as follows. deflate performs one or both of the
248 following actions:
249
250 - Compress more input starting at next_in and update next_in and avail_in
251 accordingly. If not all input can be processed (because there is not
252 enough room in the output buffer), next_in and avail_in are updated and
253 processing will resume at this point for the next call of deflate().
254
255 - Provide more output starting at next_out and update next_out and avail_out
256 accordingly. This action is forced if the parameter flush is non zero.
257 Forcing flush frequently degrades the compression ratio, so this parameter
258 should be set only when necessary (in interactive applications).
259 Some output may be provided even if flush is not set.
260
261 Before the call of deflate(), the application should ensure that at least
262 one of the actions is possible, by providing more input and/or consuming
263 more output, and updating avail_in or avail_out accordingly; avail_out
264 should never be zero before the call. The application can consume the
265 compressed output when it wants, for example when the output buffer is full
266 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
267 and with zero avail_out, it must be called again after making room in the
268 output buffer because there might be more output pending.
269
270 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
271 flushed to the output buffer and the output is aligned on a byte boundary, so
272 that the decompressor can get all input data available so far. (In particular
273 avail_in is zero after the call if enough output space has been provided
274 before the call.) Flushing may degrade compression for some compression
275 algorithms and so it should be used only when necessary.
276
277 If flush is set to Z_FULL_FLUSH, all output is flushed as with
278 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
279 restart from this point if previous compressed data has been damaged or if
280 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
281 the compression.
282
283 If deflate returns with avail_out == 0, this function must be called again
284 with the same value of the flush parameter and more output space (updated
285 avail_out), until the flush is complete (deflate returns with non-zero
286 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
287 avail_out is greater than six to avoid repeated flush markers due to
288 avail_out == 0 on return.
289
290 If the parameter flush is set to Z_FINISH, pending input is processed,
291 pending output is flushed and deflate returns with Z_STREAM_END if there
292 was enough output space; if deflate returns with Z_OK, this function must be
293 called again with Z_FINISH and more output space (updated avail_out) but no
294 more input data, until it returns with Z_STREAM_END or an error. After
295 deflate has returned Z_STREAM_END, the only possible operations on the
296 stream are deflateReset or deflateEnd.
297
298 Z_FINISH can be used immediately after deflateInit if all the compression
299 is to be done in a single step. In this case, avail_out must be at least
300 the value returned by deflateBound (see below). If deflate does not return
301 Z_STREAM_END, then it must be called again as described above.
302
303 deflate() sets strm->adler to the adler32 checksum of all input read
304 so far (that is, total_in bytes).
305
306 deflate() may update data_type if it can make a good guess about
307 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
308 binary. This field is only for information purposes and does not affect
309 the compression algorithm in any manner.
310
311 deflate() returns Z_OK if some progress has been made (more input
312 processed or more output produced), Z_STREAM_END if all input has been
313 consumed and all output has been produced (only when flush is set to
314 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
315 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
316 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
317 fatal, and deflate() can be called again with more input and more output
318 space to continue compressing.
319 */
320
321
322 int deflateEnd(z_streamp strm);
323 /*
324 All dynamically allocated data structures for this stream are freed.
325 This function discards any unprocessed input and does not flush any
326 pending output.
327
328 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
329 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
330 prematurely (some input or output was discarded). In the error case,
331 msg may be set but then points to a static string (which must not be
332 deallocated).
333 */
334
335
336 int inflateInit(z_streamp strm)
337 {
338 return inflateInit_(strm, ZLIB_VERSION.ptr, z_stream.sizeof);
339 }
340 /*
341 Initializes the internal stream state for decompression. The fields
342 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
343 the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
344 value depends on the compression method), inflateInit determines the
345 compression method from the zlib header and allocates all data structures
346 accordingly; otherwise the allocation will be deferred to the first call of
347 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
348 use default allocation functions.
349
350 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
351 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
352 version assumed by the caller. msg is set to null if there is no error
353 message. inflateInit does not perform any decompression apart from reading
354 the zlib header if present: this will be done by inflate(). (So next_in and
355 avail_in may be modified, but next_out and avail_out are unchanged.)
356 */
357
358
359 int inflate(z_streamp strm, int flush);
360 /*
361 inflate decompresses as much data as possible, and stops when the input
362 buffer becomes empty or the output buffer becomes full. It may introduce
363 some output latency (reading input without producing any output) except when
364 forced to flush.
365
366 The detailed semantics are as follows. inflate performs one or both of the
367 following actions:
368
369 - Decompress more input starting at next_in and update next_in and avail_in
370 accordingly. If not all input can be processed (because there is not
371 enough room in the output buffer), next_in is updated and processing
372 will resume at this point for the next call of inflate().
373
374 - Provide more output starting at next_out and update next_out and avail_out
375 accordingly. inflate() provides as much output as possible, until there
376 is no more input data or no more space in the output buffer (see below
377 about the flush parameter).
378
379 Before the call of inflate(), the application should ensure that at least
380 one of the actions is possible, by providing more input and/or consuming
381 more output, and updating the next_* and avail_* values accordingly.
382 The application can consume the uncompressed output when it wants, for
383 example when the output buffer is full (avail_out == 0), or after each
384 call of inflate(). If inflate returns Z_OK and with zero avail_out, it
385 must be called again after making room in the output buffer because there
386 might be more output pending.
387
388 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
389 Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
390 output as possible to the output buffer. Z_BLOCK requests that inflate() stop
391 if and when it get to the next deflate block boundary. When decoding the zlib
392 or gzip format, this will cause inflate() to return immediately after the
393 header and before the first block. When doing a raw inflate, inflate() will
394 go ahead and process the first block, and will return when it gets to the end
395 of that block, or when it runs out of data.
396
397 The Z_BLOCK option assists in appending to or combining deflate streams.
398 Also to assist in this, on return inflate() will set strm->data_type to the
399 number of unused bits in the last byte taken from strm->next_in, plus 64
400 if inflate() is currently decoding the last block in the deflate stream,
401 plus 128 if inflate() returned immediately after decoding an end-of-block
402 code or decoding the complete header up to just before the first byte of the
403 deflate stream. The end-of-block will not be indicated until all of the
404 uncompressed data from that block has been written to strm->next_out. The
405 number of unused bits may in general be greater than seven, except when
406 bit 7 of data_type is set, in which case the number of unused bits will be
407 less than eight.
408
409 inflate() should normally be called until it returns Z_STREAM_END or an
410 error. However if all decompression is to be performed in a single step
411 (a single call of inflate), the parameter flush should be set to
412 Z_FINISH. In this case all pending input is processed and all pending
413 output is flushed; avail_out must be large enough to hold all the
414 uncompressed data. (The size of the uncompressed data may have been saved
415 by the compressor for this purpose.) The next operation on this stream must
416 be inflateEnd to deallocate the decompression state. The use of Z_FINISH
417 is never required, but can be used to inform inflate that a faster approach
418 may be used for the single inflate() call.
419
420 In this implementation, inflate() always flushes as much output as
421 possible to the output buffer, and always uses the faster approach on the
422 first call. So the only effect of the flush parameter in this implementation
423 is on the return value of inflate(), as noted below, or when it returns early
424 because Z_BLOCK is used.
425
426 If a preset dictionary is needed after this call (see inflateSetDictionary
427 below), inflate sets strm-adler to the adler32 checksum of the dictionary
428 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
429 strm->adler to the adler32 checksum of all output produced so far (that is,
430 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
431 below. At the end of the stream, inflate() checks that its computed adler32
432 checksum is equal to that saved by the compressor and returns Z_STREAM_END
433 only if the checksum is correct.
434
435 inflate() will decompress and check either zlib-wrapped or gzip-wrapped
436 deflate data. The header type is detected automatically. Any information
437 contained in the gzip header is not retained, so applications that need that
438 information should instead use raw inflate, see inflateInit2() below, or
439 inflateBack() and perform their own processing of the gzip header and
440 trailer.
441
442 inflate() returns Z_OK if some progress has been made (more input processed
443 or more output produced), Z_STREAM_END if the end of the compressed data has
444 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
445 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
446 corrupted (input stream not conforming to the zlib format or incorrect check
447 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
448 if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
449 Z_BUF_ERROR if no progress is possible or if there was not enough room in the
450 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
451 inflate() can be called again with more input and more output space to
452 continue decompressing. If Z_DATA_ERROR is returned, the application may then
453 call inflateSync() to look for a good compression block if a partial recovery
454 of the data is desired.
455 */
456
457
458 int inflateEnd(z_streamp strm);
459 /*
460 All dynamically allocated data structures for this stream are freed.
461 This function discards any unprocessed input and does not flush any
462 pending output.
463
464 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
465 was inconsistent. In the error case, msg may be set but then points to a
466 static string (which must not be deallocated).
467 */
468
469 /* Advanced functions */
470
471 /*
472 The following functions are needed only in some special applications.
473 */
474
475 int deflateInit2(z_streamp strm,
476 int level,
477 int method,
478 int windowBits,
479 int memLevel,
480 int strategy)
481 {
482 return deflateInit2_(strm, level, method, windowBits, memLevel,
483 strategy, ZLIB_VERSION.ptr, z_stream.sizeof);
484 }
485 /*
486 This is another version of deflateInit with more compression options. The
487 fields next_in, zalloc, zfree and opaque must be initialized before by
488 the caller.
489
490 The method parameter is the compression method. It must be Z_DEFLATED in
491 this version of the library.
492
493 The windowBits parameter is the base two logarithm of the window size
494 (the size of the history buffer). It should be in the range 8..15 for this
495 version of the library. Larger values of this parameter result in better
496 compression at the expense of memory usage. The default value is 15 if
497 deflateInit is used instead.
498
499 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
500 determines the window size. deflate() will then generate raw deflate data
501 with no zlib header or trailer, and will not compute an adler32 check value.
502
503 windowBits can also be greater than 15 for optional gzip encoding. Add
504 16 to windowBits to write a simple gzip header and trailer around the
505 compressed data instead of a zlib wrapper. The gzip header will have no
506 file name, no extra data, no comment, no modification time (set to zero),
507 no header crc, and the operating system will be set to 255 (unknown).
508
509 The memLevel parameter specifies how much memory should be allocated
510 for the internal compression state. memLevel=1 uses minimum memory but
511 is slow and reduces compression ratio; memLevel=9 uses maximum memory
512 for optimal speed. The default value is 8. See zconf.h for total memory
513 usage as a function of windowBits and memLevel.
514
515 The strategy parameter is used to tune the compression algorithm. Use the
516 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
517 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
518 string match), or Z_RLE to limit match distances to one (run-length
519 encoding). Filtered data consists mostly of small values with a somewhat
520 random distribution. In this case, the compression algorithm is tuned to
521 compress them better. The effect of Z_FILTERED is to force more Huffman
522 coding and less string matching; it is somewhat intermediate between
523 Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
524 Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
525 parameter only affects the compression ratio but not the correctness of the
526 compressed output even if it is not set appropriately.
527
528 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
529 memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
530 method). msg is set to null if there is no error message. deflateInit2 does
531 not perform any compression: this will be done by deflate().
532 */
533
534 int deflateSetDictionary(z_streamp strm, ubyte* dictionary, uint dictLength);
535 /*
536 Initializes the compression dictionary from the given byte sequence
537 without producing any compressed output. This function must be called
538 immediately after deflateInit, deflateInit2 or deflateReset, before any
539 call of deflate. The compressor and decompressor must use exactly the same
540 dictionary (see inflateSetDictionary).
541
542 The dictionary should consist of strings (byte sequences) that are likely
543 to be encountered later in the data to be compressed, with the most commonly
544 used strings preferably put towards the end of the dictionary. Using a
545 dictionary is most useful when the data to be compressed is short and can be
546 predicted with good accuracy; the data can then be compressed better than
547 with the default empty dictionary.
548
549 Depending on the size of the compression data structures selected by
550 deflateInit or deflateInit2, a part of the dictionary may in effect be
551 discarded, for example if the dictionary is larger than the window size in
552 deflate or deflate2. Thus the strings most likely to be useful should be
553 put at the end of the dictionary, not at the front.
554
555 Upon return of this function, strm->adler is set to the adler32 value
556 of the dictionary; the decompressor may later use this value to determine
557 which dictionary has been used by the compressor. (The adler32 value
558 applies to the whole dictionary even if only a subset of the dictionary is
559 actually used by the compressor.) If a raw deflate was requested, then the
560 adler32 value is not computed and strm->adler is not set.
561
562 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
563 parameter is invalid (such as NULL dictionary) or the stream state is
564 inconsistent (for example if deflate has already been called for this stream
565 or if the compression method is bsort). deflateSetDictionary does not
566 perform any compression: this will be done by deflate().
567 */
568
569 int deflateCopy(z_streamp dest, z_streamp source);
570 /*
571 Sets the destination stream as a complete copy of the source stream.
572
573 This function can be useful when several compression strategies will be
574 tried, for example when there are several ways of pre-processing the input
575 data with a filter. The streams that will be discarded should then be freed
576 by calling deflateEnd. Note that deflateCopy duplicates the internal
577 compression state which can be quite large, so this strategy is slow and
578 can consume lots of memory.
579
580 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
581 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
582 (such as zalloc being NULL). msg is left unchanged in both source and
583 destination.
584 */
585
586 int deflateReset(z_streamp strm);
587 /*
588 This function is equivalent to deflateEnd followed by deflateInit,
589 but does not free and reallocate all the internal compression state.
590 The stream will keep the same compression level and any other attributes
591 that may have been set by deflateInit2.
592
593 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
594 stream state was inconsistent (such as zalloc or state being NULL).
595 */
596
597 int deflateParams(z_streamp strm, int level, int strategy);
598 /*
599 Dynamically update the compression level and compression strategy. The
600 interpretation of level and strategy is as in deflateInit2. This can be
601 used to switch between compression and straight copy of the input data, or
602 to switch to a different kind of input data requiring a different
603 strategy. If the compression level is changed, the input available so far
604 is compressed with the old level (and may be flushed); the new level will
605 take effect only at the next call of deflate().
606
607 Before the call of deflateParams, the stream state must be set as for
608 a call of deflate(), since the currently available input may have to
609 be compressed and flushed. In particular, strm->avail_out must be non-zero.
610
611 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
612 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
613 if strm->avail_out was zero.
614 */
615
616 uint deflateBound(z_streamp strm, uint Culong_t);
617 /*
618 deflateBound() returns an upper bound on the compressed size after
619 deflation of sourceLen bytes. It must be called after deflateInit()
620 or deflateInit2(). This would be used to allocate an output buffer
621 for deflation in a single pass, and so would be called before deflate().
622 */
623
624 int deflatePrime(z_streamp strm, int bits, int value);
625 /*
626 deflatePrime() inserts bits in the deflate output stream. The intent
627 is that this function is used to start off the deflate output with the
628 bits leftover from a previous deflate stream when appending to it. As such,
629 this function can only be used for raw deflate, and must be used before the
630 first deflate() call after a deflateInit2() or deflateReset(). bits must be
631 less than or equal to 16, and that many of the least significant bits of
632 value will be inserted in the output.
633
634 deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
635 stream state was inconsistent.
636 */
637
638 int inflateInit2(z_streamp strm, int windowBits)
639 {
640 return inflateInit2_(strm, windowBits, ZLIB_VERSION.ptr, z_stream.sizeof);
641 }
642 /*
643 This is another version of inflateInit with an extra parameter. The
644 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
645 before by the caller.
646
647 The windowBits parameter is the base two logarithm of the maximum window
648 size (the size of the history buffer). It should be in the range 8..15 for
649 this version of the library. The default value is 15 if inflateInit is used
650 instead. windowBits must be greater than or equal to the windowBits value
651 provided to deflateInit2() while compressing, or it must be equal to 15 if
652 deflateInit2() was not used. If a compressed stream with a larger window
653 size is given as input, inflate() will return with the error code
654 Z_DATA_ERROR instead of trying to allocate a larger window.
655
656 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
657 determines the window size. inflate() will then process raw deflate data,
658 not looking for a zlib or gzip header, not generating a check value, and not
659 looking for any check values for comparison at the end of the stream. This
660 is for use with other formats that use the deflate compressed data format
661 such as zip. Those formats provide their own check values. If a custom
662 format is developed using the raw deflate format for compressed data, it is
663 recommended that a check value such as an adler32 or a crc32 be applied to
664 the uncompressed data as is done in the zlib, gzip, and zip formats. For
665 most applications, the zlib format should be used as is. Note that comments
666 above on the use in deflateInit2() applies to the magnitude of windowBits.
667
668 windowBits can also be greater than 15 for optional gzip decoding. Add
669 32 to windowBits to enable zlib and gzip decoding with automatic header
670 detection, or add 16 to decode only the gzip format (the zlib format will
671 return a Z_DATA_ERROR).
672
673 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
674 memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
675 memLevel). msg is set to null if there is no error message. inflateInit2
676 does not perform any decompression apart from reading the zlib header if
677 present: this will be done by inflate(). (So next_in and avail_in may be
678 modified, but next_out and avail_out are unchanged.)
679 */
680
681 int inflateSetDictionary(z_streamp strm, ubyte* dictionary, uint dictLength);
682 /*
683 Initializes the decompression dictionary from the given uncompressed byte
684 sequence. This function must be called immediately after a call of inflate
685 if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
686 can be determined from the adler32 value returned by this call of
687 inflate. The compressor and decompressor must use exactly the same
688 dictionary (see deflateSetDictionary).
689
690 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
691 parameter is invalid (such as NULL dictionary) or the stream state is
692 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
693 expected one (incorrect adler32 value). inflateSetDictionary does not
694 perform any decompression: this will be done by subsequent calls of
695 inflate().
696 */
697
698 int inflateSync(z_streamp strm);
699 /*
700 Skips invalid compressed data until a full flush point (see above the
701 description of deflate with Z_FULL_FLUSH) can be found, or until all
702 available input is skipped. No output is provided.
703
704 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
705 if no more input was provided, Z_DATA_ERROR if no flush point has been found,
706 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
707 case, the application may save the current current value of total_in which
708 indicates where valid compressed data was found. In the error case, the
709 application may repeatedly call inflateSync, providing more input each time,
710 until success or end of the input data.
711 */
712
713 int inflateCopy (z_streamp dest, z_streamp source);
714 /*
715 Sets the destination stream as a complete copy of the source stream.
716
717 This function can be useful when randomly accessing a large stream. The
718 first pass through the stream can periodically record the inflate state,
719 allowing restarting inflate at those points when randomly accessing the
720 stream.
721
722 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
723 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
724 (such as zalloc being NULL). msg is left unchanged in both source and
725 destination.
726 */
727
728 int inflateReset(z_streamp strm);
729 /*
730 This function is equivalent to inflateEnd followed by inflateInit,
731 but does not free and reallocate all the internal decompression state.
732 The stream will keep attributes that may have been set by inflateInit2.
733
734 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
735 stream state was inconsistent (such as zalloc or state being NULL).
736 */
737
738
739 int inflateBackInit(z_stream* strm, int windowBits, ubyte* window)
740 {
741 return inflateBackInit_(strm, windowBits, window, ZLIB_VERSION.ptr, z_stream.sizeof);
742 }
743 /*
744 Initialize the internal stream state for decompression using inflateBack()
745 calls. The fields zalloc, zfree and opaque in strm must be initialized
746 before the call. If zalloc and zfree are Z_NULL, then the default library-
747 derived memory allocation routines are used. windowBits is the base two
748 logarithm of the window size, in the range 8..15. window is a caller
749 supplied buffer of that size. Except for special applications where it is
750 assured that deflate was used with small window sizes, windowBits must be 15
751 and a 32K byte window must be supplied to be able to decompress general
752 deflate streams.
753
754 See inflateBack() for the usage of these routines.
755
756 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
757 the paramaters are invalid, Z_MEM_ERROR if the internal state could not
758 be allocated, or Z_VERSION_ERROR if the version of the library does not
759 match the version of the header file.
760 */
761
762 alias uint function(void*, ubyte**) in_func;
763 alias int function(void*, ubyte*, uint) out_func;
764
765 int inflateBack(z_stream* strm,
766 in_func f_in,
767 void* in_desc,
768 out_func f_out,
769 void* out_desc);
770 /*
771 inflateBack() does a raw inflate with a single call using a call-back
772 interface for input and output. This is more efficient than inflate() for
773 file i/o applications in that it avoids copying between the output and the
774 sliding window by simply making the window itself the output buffer. This
775 function trusts the application to not change the output buffer passed by
776 the output function, at least until inflateBack() returns.
777
778 inflateBackInit() must be called first to allocate the internal state
779 and to initialize the state with the user-provided window buffer.
780 inflateBack() may then be used multiple times to inflate a complete, raw
781 deflate stream with each call. inflateBackEnd() is then called to free
782 the allocated state.
783
784 A raw deflate stream is one with no zlib or gzip header or trailer.
785 This routine would normally be used in a utility that reads zip or gzip
786 files and writes out uncompressed files. The utility would decode the
787 header and process the trailer on its own, hence this routine expects
788 only the raw deflate stream to decompress. This is different from the
789 normal behavior of inflate(), which expects either a zlib or gzip header and
790 trailer around the deflate stream.
791
792 inflateBack() uses two subroutines supplied by the caller that are then
793 called by inflateBack() for input and output. inflateBack() calls those
794 routines until it reads a complete deflate stream and writes out all of the
795 uncompressed data, or until it encounters an error. The function's
796 parameters and return types are defined above in the in_func and out_func
797 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
798 number of bytes of provided input, and a pointer to that input in buf. If
799 there is no input available, in() must return zero--buf is ignored in that
800 case--and inflateBack() will return a buffer error. inflateBack() will call
801 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
802 should return zero on success, or non-zero on failure. If out() returns
803 non-zero, inflateBack() will return with an error. Neither in() nor out()
804 are permitted to change the contents of the window provided to
805 inflateBackInit(), which is also the buffer that out() uses to write from.
806 The length written by out() will be at most the window size. Any non-zero
807 amount of input may be provided by in().
808
809 For convenience, inflateBack() can be provided input on the first call by
810 setting strm->next_in and strm->avail_in. If that input is exhausted, then
811 in() will be called. Therefore strm->next_in must be initialized before
812 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
813 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
814 must also be initialized, and then if strm->avail_in is not zero, input will
815 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
816
817 The in_desc and out_desc parameters of inflateBack() is passed as the
818 first parameter of in() and out() respectively when they are called. These
819 descriptors can be optionally used to pass any information that the caller-
820 supplied in() and out() functions need to do their job.
821
822 On return, inflateBack() will set strm->next_in and strm->avail_in to
823 pass back any unused input that was provided by the last in() call. The
824 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
825 if in() or out() returned an error, Z_DATA_ERROR if there was a format
826 error in the deflate stream (in which case strm->msg is set to indicate the
827 nature of the error), or Z_STREAM_ERROR if the stream was not properly
828 initialized. In the case of Z_BUF_ERROR, an input or output error can be
829 distinguished using strm->next_in which will be Z_NULL only if in() returned
830 an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
831 out() returning non-zero. (in() will always be called before out(), so
832 strm->next_in is assured to be defined if out() returns non-zero.) Note
833 that inflateBack() cannot return Z_OK.
834 */
835
836 int inflateBackEnd(z_stream* strm);
837 /*
838 All memory allocated by inflateBackInit() is freed.
839
840 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
841 state was inconsistent.
842 */
843
844 uint zlibCompileFlags();
845 /* Return flags indicating compile-time options.
846
847 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
848 1.0: size of uInt
849 3.2: size of uLong
850 5.4: size of voidpf (pointer)
851 7.6: size of z_off_t
852
853 Compiler, assembler, and debug options:
854 8: DEBUG
855 9: ASMV or ASMINF -- use ASM code
856 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
857 11: 0 (reserved)
858
859 One-time table building (smaller code, but not thread-safe if true):
860 12: BUILDFIXED -- build static block decoding tables when needed
861 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
862 14,15: 0 (reserved)
863
864 Library content (indicates missing functionality):
865 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
866 deflate code when not needed)
867 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
868 and decode gzip streams (to avoid linking crc code)
869 18-19: 0 (reserved)
870
871 Operation variations (changes in library functionality):
872 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
873 21: FASTEST -- deflate algorithm with only one, lowest compression level
874 22,23: 0 (reserved)
875
876 The sprintf variant used by gzprintf (zero is best):
877 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
878 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
879 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
880
881 Remainder:
882 27-31: 0 (reserved)
883 */
884
885 /* utility functions */
886
887 /*
888 The following utility functions are implemented on top of the
889 basic stream-oriented functions. To simplify the interface, some
890 default options are assumed (compression level and memory usage,
891 standard memory allocation functions). The source code of these
892 utility functions can easily be modified if you need special options.
893 */
894
895 int compress(ubyte* dest,
896 Culong_t* destLen,
897 ubyte* source,
898 Culong_t sourceLen);
899 /*
900 Compresses the source buffer into the destination buffer. sourceLen is
901 the byte length of the source buffer. Upon entry, destLen is the total
902 size of the destination buffer, which must be at least the value returned
903 by compressBound(sourceLen). Upon exit, destLen is the actual size of the
904 compressed buffer.
905 This function can be used to compress a whole file at once if the
906 input file is mmap'ed.
907 compress returns Z_OK if success, Z_MEM_ERROR if there was not
908 enough memory, Z_BUF_ERROR if there was not enough room in the output
909 buffer.
910 */
911
912 int compress2(ubyte* dest,
913 Culong_t* destLen,
914 ubyte* source,
915 Culong_t sourceLen,
916 int level);
917 /*
918 Compresses the source buffer into the destination buffer. The level
919 parameter has the same meaning as in deflateInit. sourceLen is the byte
920 length of the source buffer. Upon entry, destLen is the total size of the
921 destination buffer, which must be at least the value returned by
922 compressBound(sourceLen). Upon exit, destLen is the actual size of the
923 compressed buffer.
924
925 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
926 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
927 Z_STREAM_ERROR if the level parameter is invalid.
928 */
929
930 uint compressBound(Culong_t sourceLen);
931 /*
932 compressBound() returns an upper bound on the compressed size after
933 compress() or compress2() on sourceLen bytes. It would be used before
934 a compress() or compress2() call to allocate the destination buffer.
935 */
936
937 int uncompress(ubyte* dest,
938 uint* Culong_t,
939 ubyte* source,
940 uint Culong_t);
941 /*
942 Decompresses the source buffer into the destination buffer. sourceLen is
943 the byte length of the source buffer. Upon entry, destLen is the total
944 size of the destination buffer, which must be large enough to hold the
945 entire uncompressed data. (The size of the uncompressed data must have
946 been saved previously by the compressor and transmitted to the decompressor
947 by some mechanism outside the scope of this compression library.)
948 Upon exit, destLen is the actual size of the compressed buffer.
949 This function can be used to decompress a whole file at once if the
950 input file is mmap'ed.
951
952 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
953 enough memory, Z_BUF_ERROR if there was not enough room in the output
954 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
955 */
956
957
958 typedef void* gzFile;
959 alias int z_off_t; // file offset
960
961 gzFile gzopen(char* path, char* mode);
962 /*
963 Opens a gzip (.gz) file for reading or writing. The mode parameter
964 is as in fopen ("rb" or "wb") but can also include a compression level
965 ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
966 Huffman only compression as in "wb1h", or 'R' for run-length encoding
967 as in "wb1R". (See the description of deflateInit2 for more information
968 about the strategy parameter.)
969
970 gzopen can be used to read a file which is not in gzip format; in this
971 case gzread will directly read from the file without decompression.
972
973 gzopen returns NULL if the file could not be opened or if there was
974 insufficient memory to allocate the (de)compression state; errno
975 can be checked to distinguish the two cases (if errno is zero, the
976 zlib error is Z_MEM_ERROR). */
977
978 gzFile gzdopen(int fd, char* mode);
979 /*
980 gzdopen() associates a gzFile with the file descriptor fd. File
981 descriptors are obtained from calls like open, dup, creat, pipe or
982 fileno (in the file has been previously opened with fopen).
983 The mode parameter is as in gzopen.
984 The next call of gzclose on the returned gzFile will also close the
985 file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
986 descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
987 gzdopen returns NULL if there was insufficient memory to allocate
988 the (de)compression state.
989 */
990
991 int gzsetparams(gzFile file, int level, int strategy);
992 /*
993 Dynamically update the compression level or strategy. See the description
994 of deflateInit2 for the meaning of these parameters.
995 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
996 opened for writing.
997 */
998
999 int gzread(gzFile file, void* buf, uint len);
1000 /*
1001 Reads the given number of uncompressed bytes from the compressed file.
1002 If the input file was not in gzip format, gzread copies the given number
1003 of bytes into the buffer.
1004 gzread returns the number of uncompressed bytes actually read (0 for
1005 end of file, -1 for error). */
1006
1007 int gzwrite(gzFile file, void* buf, uint len);
1008 /*
1009 Writes the given number of uncompressed bytes into the compressed file.
1010 gzwrite returns the number of uncompressed bytes actually written
1011 (0 in case of error).
1012 */
1013
1014 int gzprintf(gzFile file, char* format, ...);
1015 /*
1016 Converts, formats, and writes the args to the compressed file under
1017 control of the format string, as in fprintf. gzprintf returns the number of
1018 uncompressed bytes actually written (0 in case of error). The number of
1019 uncompressed bytes written is limited to 4095. The caller should assure that
1020 this limit is not exceeded. If it is exceeded, then gzprintf() will return
1021 return an error (0) with nothing written. In this case, there may also be a
1022 buffer overflow with unpredictable consequences, which is possible only if
1023 zlib was compiled with the insecure functions sprintf() or vsprintf()
1024 because the secure snprintf() or vsnprintf() functions were not available.
1025 */
1026
1027 int gzputs(gzFile file, char* s);
1028 /*
1029 Writes the given null-terminated string to the compressed file, excluding
1030 the terminating null character.
1031 gzputs returns the number of characters written, or -1 in case of error.
1032 */
1033
1034 char* gzgets(gzFile file, char* buf, int len);
1035 /*
1036 Reads bytes from the compressed file until len-1 characters are read, or
1037 a newline character is read and transferred to buf, or an end-of-file
1038 condition is encountered. The string is then terminated with a null
1039 character.
1040 gzgets returns buf, or Z_NULL in case of error.
1041 */
1042
1043 int gzputc(gzFile file, int c);
1044 /*
1045 Writes c, converted to an unsigned char, into the compressed file.
1046 gzputc returns the value that was written, or -1 in case of error.
1047 */
1048
1049 int gzgetc(gzFile file);
1050 /*
1051 Reads one byte from the compressed file. gzgetc returns this byte
1052 or -1 in case of end of file or error.
1053 */
1054
1055 int gzungetc(int c, gzFile file);
1056 /*
1057 Push one character back onto the stream to be read again later.
1058 Only one character of push-back is allowed. gzungetc() returns the
1059 character pushed, or -1 on failure. gzungetc() will fail if a
1060 character has been pushed but not read yet, or if c is -1. The pushed
1061 character will be discarded if the stream is repositioned with gzseek()
1062 or gzrewind().
1063 */
1064
1065 int gzflush(gzFile file, int flush);
1066 /*
1067 Flushes all pending output into the compressed file. The parameter
1068 flush is as in the deflate() function. The return value is the zlib
1069 error number (see function gzerror below). gzflush returns Z_OK if
1070 the flush parameter is Z_FINISH and all output could be flushed.
1071 gzflush should be called only when strictly necessary because it can
1072 degrade compression.
1073 */
1074
1075 z_off_t gzseek(gzFile file, z_off_t offset, int whence);
1076 /*
1077 Sets the starting position for the next gzread or gzwrite on the
1078 given compressed file. The offset represents a number of bytes in the
1079 uncompressed data stream. The whence parameter is defined as in lseek(2);
1080 the value SEEK_END is not supported.
1081 If the file is opened for reading, this function is emulated but can be
1082 extremely slow. If the file is opened for writing, only forward seeks are
1083 supported; gzseek then compresses a sequence of zeroes up to the new
1084 starting position.
1085
1086 gzseek returns the resulting offset location as measured in bytes from
1087 the beginning of the uncompressed stream, or -1 in case of error, in
1088 particular if the file is opened for writing and the new starting position
1089 would be before the current position.
1090 */
1091
1092 int gzrewind(gzFile file);
1093 /*
1094 Rewinds the given file. This function is supported only for reading.
1095
1096 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1097 */
1098
1099 z_off_t gztell(gzFile file);
1100 /*
1101 Returns the starting position for the next gzread or gzwrite on the
1102 given compressed file. This position represents a number of bytes in the
1103 uncompressed data stream.
1104
1105 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1106 */
1107
1108 int gzeof(gzFile file);
1109 /*
1110 Returns 1 when EOF has previously been detected reading the given
1111 input stream, otherwise zero.
1112 */
1113
1114 int gzclose(gzFile file);
1115 /*
1116 Flushes all pending output if necessary, closes the compressed file
1117 and deallocates all the (de)compression state. The return value is the zlib
1118 error number (see function gzerror below).
1119 */
1120
1121 char* gzerror(gzFile file, int *errnum);
1122 /*
1123 Returns the error message for the last error which occurred on the
1124 given compressed file. errnum is set to zlib error number. If an
1125 error occurred in the file system and not in the compression library,
1126 errnum is set to Z_ERRNO and the application may consult errno
1127 to get the exact error code.
1128 */
1129
1130 void gzclearerr (gzFile file);
1131 /*
1132 Clears the error and end-of-file flags for file. This is analogous to the
1133 clearerr() function in stdio. This is useful for continuing to read a gzip
1134 file that is being written concurrently.
1135 */
1136
1137 /* checksum functions */
1138
1139 /*
1140 These functions are not related to compression but are exported
1141 anyway because they might be useful in applications using the
1142 compression library.
1143 */
1144
1145 Culong_t adler32 (Culong_t adler, ubyte *buf, uint len);
1146
1147 /*
1148 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1149 return the updated checksum. If buf is NULL, this function returns
1150 the required initial value for the checksum.
1151 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1152 much faster. Usage example:
1153
1154 uint adler = adler32(0L, Z_NULL, 0);
1155
1156 while (read_buffer(buffer, length) != EOF) {
1157 adler = adler32(adler, buffer, length);
1158 }
1159 if (adler != original_adler) error();
1160 */
1161
1162 Culong_t crc32(Culong_t crc, ubyte *buf, uint len);
1163 /*
1164 Update a running crc with the bytes buf[0..len-1] and return the updated
1165 crc. If buf is NULL, this function returns the required initial value
1166 for the crc. Pre- and post-conditioning (one's complement) is performed
1167 within this function so it shouldn't be done by the application.
1168 Usage example:
1169
1170 uint crc = crc32(0L, Z_NULL, 0);
1171
1172 while (read_buffer(buffer, length) != EOF) {
1173 crc = crc32(crc, buffer, length);
1174 }
1175 if (crc != original_crc) error();
1176 */
1177
1178
1179 /* various hacks, don't look :) */
1180
1181 /* deflateInit and inflateInit are macros to allow checking the zlib version
1182 * and the compiler's view of z_stream:
1183 */
1184 int deflateInit_(z_streamp strm,
1185 int level,
1186 char* versionx,
1187 int stream_size);
1188
1189 int inflateInit_(z_streamp strm,
1190 char* versionx,
1191 int stream_size);
1192
1193 int deflateInit2_(z_streamp strm,
1194 int level,
1195 int method,
1196 int windowBits,
1197 int memLevel,
1198 int strategy,
1199 char* versionx,
1200 int stream_size);
1201
1202 int inflateBackInit_(z_stream* strm,
1203 int windowBits,
1204 ubyte* window,
1205 char* z_version,
1206 int stream_size);
1207
1208 int inflateInit2_(z_streamp strm,
1209 int windowBits,
1210 char* versionx,
1211 int stream_size);
1212
1213 char* zError(int err);
1214 int inflateSyncPoint(z_streamp z);
1215 Culong_t* get_crc_table();