MRPT  1.9.9
zlib.h
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9 
10 #pragma once
11 
12 #include "zconf.h"
13 
14 #ifdef __cplusplus
15 extern "C"
16 {
17 #endif
18 
19 #define ZLIB_VERSION "1.2.3"
20 #define ZLIB_VERNUM 0x1230
21 
22  /*
23  The 'zlib' compression library provides in-memory compression and
24  decompression functions, including integrity checks of the uncompressed
25  data. This version of the library supports only one compression method
26  (deflation) but other algorithms will be added later and will have the
27  same stream interface.
28 
29  Compression can be done in a single step if the buffers are large
30  enough (for example if an input file is mmap'ed), or can be done by
31  repeated calls of the compression function. In the latter case, the
32  application must provide more input and/or consume the output
33  (providing more output space) before each call.
34 
35  The compressed data format used by default by the in-memory functions
36  is the zlib format, which is a zlib wrapper documented in RFC 1950,
37  wrapped around a deflate stream, which is itself documented in RFC 1951.
38 
39  The library also supports reading and writing files in gzip (.gz)
40  format with an interface similar to that of stdio using the functions that
41  start with "gz". The gzip format is different from the zlib format. gzip
42  is a gzip wrapper, documented in RFC 1952, wrapped around a deflate
43  stream.
44 
45  This library can optionally read and write gzip streams in memory as
46  well.
47 
48  The zlib format was designed to be compact and fast for use in memory
49  and on communications channels. The gzip format was designed for single-
50  file compression on file systems, has a larger header than zlib to
51  maintain directory information, and uses a different, slower check method
52  than zlib.
53 
54  The library does not install any signal handler. The decoder checks
55  the consistency of the compressed data, so the library should never
56  crash even in case of corrupted input.
57  */
58 
59  typedef voidpf(*alloc_func) OF((voidpf opaque, uInt items, uInt size));
60  typedef void(*free_func) OF((voidpf opaque, voidpf address));
61 
62  struct internal_state;
63 
64  typedef struct z_stream_s
65  {
66  Bytef* next_in; /* next input byte */
67  uInt avail_in; /* number of bytes available at next_in */
68  uLong total_in; /* total nb of input bytes read so far */
69 
70  Bytef* next_out; /* next output byte should be put there */
71  uInt avail_out; /* remaining free space at next_out */
72  uLong total_out; /* total nb of bytes output so far */
73 
74  char* msg; /* last error message, nullptr if no error */
75  struct internal_state FAR* state; /* not visible by applications */
76 
77  alloc_func zalloc; /* used to allocate the internal state */
78  free_func zfree; /* used to free the internal state */
79  voidpf opaque; /* private data object passed to zalloc and zfree */
80 
81  int data_type; /* best guess about the data type: binary or text */
82  uLong adler; /* adler32 value of the uncompressed data */
83  uLong reserved; /* reserved for future use */
84  } z_stream;
85 
87 
88  /*
89  gzip header information passed to and from zlib routines. See RFC 1952
90  for more details on the meanings of these fields.
91  */
92  typedef struct gz_header_s
93  {
94  int text; /* true if compressed data believed to be text */
95  uLong time; /* modification time */
96  int xflags; /* extra flags (not used when writing a gzip file) */
97  int os; /* operating system */
98  Bytef* extra; /* pointer to extra field or Z_NULL if none */
99  uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
100  uInt extra_max; /* space at extra (only when reading header) */
101  Bytef* name; /* pointer to zero-terminated file name or Z_NULL */
102  uInt name_max; /* space at name (only when reading header) */
103  Bytef* comment; /* pointer to zero-terminated comment or Z_NULL */
104  uInt comm_max; /* space at comment (only when reading header) */
105  int hcrc; /* true if there was or will be a header crc */
106  int done; /* true when done reading gzip header (not used
107  when writing a gzip file) */
108  } gz_header;
109 
111 
112  /*
113  The application must update next_in and avail_in when avail_in has
114  dropped to zero. It must update next_out and avail_out when avail_out
115  has dropped to zero. The application must initialize zalloc, zfree and
116  opaque before calling the init function. All other fields are set by the
117  compression library and must not be updated by the application.
118 
119  The opaque value provided by the application will be passed as the first
120  parameter for calls of zalloc and zfree. This can be useful for custom
121  memory management. The compression library attaches no meaning to the
122  opaque value.
123 
124  zalloc must return Z_NULL if there is not enough memory for the object.
125  If zlib is used in a multi-threaded application, zalloc and zfree must be
126  thread safe.
127 
128  On 16-bit systems, the functions zalloc and zfree must be able to
129  allocate exactly 65536 bytes, but will not be required to allocate more
130  than this if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On
131  MSDOS, pointers returned by zalloc for objects of exactly 65536 bytes
132  *must* have their offset normalized to zero. The default allocation
133  function provided by this library ensures this (see zutil.c). To reduce
134  memory requirements and avoid any allocation of 64K objects, at the
135  expense of compression ratio, compile the library with -DMAX_WBITS=14
136  (see zconf.h).
137 
138  The fields total_in and total_out can be used for statistics or
139  progress reports. After compression, total_in holds the total size of
140  the uncompressed data and may be saved for use in the decompressor
141  (particularly if the decompressor wants to decompress everything in
142  a single step).
143  */
144 
145  /* constants */
146 
147 #define Z_NO_FLUSH 0
148 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
149 #define Z_SYNC_FLUSH 2
150 #define Z_FULL_FLUSH 3
151 #define Z_FINISH 4
152 #define Z_BLOCK 5
153  /* Allowed flush values; see deflate() and inflate() below for details */
154 
155 #define Z_OK 0
156 #define Z_STREAM_END 1
157 #define Z_NEED_DICT 2
158 #define Z_ERRNO (-1)
159 #define Z_STREAM_ERROR (-2)
160 #define Z_DATA_ERROR (-3)
161 #define Z_MEM_ERROR (-4)
162 #define Z_BUF_ERROR (-5)
163 #define Z_VERSION_ERROR (-6)
164  /* Return codes for the compression/decompression functions. Negative
165  * values are errors, positive values are used for special but normal
166  * events.
167  */
168 
169 #define Z_NO_COMPRESSION 0
170 #define Z_BEST_SPEED 1
171 #define Z_BEST_COMPRESSION 9
172 #define Z_DEFAULT_COMPRESSION (-1)
173  /* compression levels */
174 
175 #define Z_FILTERED 1
176 #define Z_HUFFMAN_ONLY 2
177 #define Z_RLE 3
178 #define Z_FIXED 4
179 #define Z_DEFAULT_STRATEGY 0
180  /* compression strategy; see deflateInit2() below for details */
181 
182 #define Z_BINARY 0
183 #define Z_TEXT 1
184 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
185 #define Z_UNKNOWN 2
186  /* Possible values of the data_type field (though see inflate()) */
187 
188 #define Z_DEFLATED 8
189  /* The deflate compression method (the only one supported in this version)
190  */
191 
192 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
193 
194 #define zlib_version zlibVersion()
195  /* for compatibility with versions < 1.0.2 */
196 
197  /* basic functions */
198 
199  ZEXTERN const char* ZEXPORT zlibVersion OF((void));
200  /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
201  If the first character differs, the library code actually used is
202  not compatible with the zlib.h header file used by the application.
203  This check is automatically made by deflateInit and inflateInit.
204  */
205 
206  /*
207  ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
208 
209  Initializes the internal stream state for compression. The fields
210  zalloc, zfree and opaque must be initialized before by the caller.
211  If zalloc and zfree are set to Z_NULL, deflateInit updates them to
212  use default allocation functions.
213 
214  The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and
215  9: 1 gives best speed, 9 gives best compression, 0 gives no compression at
216  all (the input data is simply copied a block at a time).
217  Z_DEFAULT_COMPRESSION requests a default compromise between speed and
218  compression (currently equivalent to level 6).
219 
220  deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
221  enough memory, Z_STREAM_ERROR if level is not a valid compression level,
222  Z_VERSION_ERROR if the zlib library version (zlib_version) is
223  incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
224  set to null if there is no error message. deflateInit does not perform any
225  compression: this will be done by deflate().
226  */
227 
228  ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
229  /*
230  deflate compresses as much data as possible, and stops when the input
231  buffer becomes empty or the output buffer becomes full. It may introduce
232  some output latency (reading input without producing any output) except
233  when forced to flush.
234 
235  The detailed semantics are as follows. deflate performs one or both of
236  the following actions:
237 
238  - Compress more input starting at next_in and update next_in and avail_in
239  accordingly. If not all input can be processed (because there is not
240  enough room in the output buffer), next_in and avail_in are updated and
241  processing will resume at this point for the next call of deflate().
242 
243  - Provide more output starting at next_out and update next_out and
244  avail_out accordingly. This action is forced if the parameter flush is non
245  zero. Forcing flush frequently degrades the compression ratio, so this
246  parameter should be set only when necessary (in interactive applications).
247  Some output may be provided even if flush is not set.
248 
249  Before the call of deflate(), the application should ensure that at least
250  one of the actions is possible, by providing more input and/or consuming
251  more output, and updating avail_in or avail_out accordingly; avail_out
252  should never be zero before the call. The application can consume the
253  compressed output when it wants, for example when the output buffer is
254  full (avail_out == 0), or after each call of deflate(). If deflate returns
255  Z_OK and with zero avail_out, it must be called again after making room in
256  the output buffer because there might be more output pending.
257 
258  Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate
259  to decide how much data to accumualte before producing output, in order to
260  maximize compression.
261 
262  If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
263  flushed to the output buffer and the output is aligned on a byte boundary,
264  so that the decompressor can get all input data available so far. (In
265  particular avail_in is zero after the call if enough output space has been
266  provided before the call.) Flushing may degrade compression for some
267  compression algorithms and so it should be used only when necessary.
268 
269  If flush is set to Z_FULL_FLUSH, all output is flushed as with
270  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
271  restart from this point if previous compressed data has been damaged or if
272  random access is desired. Using Z_FULL_FLUSH too often can seriously
273  degrade compression.
274 
275  If deflate returns with avail_out == 0, this function must be called
276  again with the same value of the flush parameter and more output space
277  (updated avail_out), until the flush is complete (deflate returns with
278  non-zero avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make
279  sure that avail_out is greater than six to avoid repeated flush markers
280  due to avail_out == 0 on return.
281 
282  If the parameter flush is set to Z_FINISH, pending input is processed,
283  pending output is flushed and deflate returns with Z_STREAM_END if there
284  was enough output space; if deflate returns with Z_OK, this function must
285  be called again with Z_FINISH and more output space (updated avail_out)
286  but no more input data, until it returns with Z_STREAM_END or an error.
287  After deflate has returned Z_STREAM_END, the only possible operations on
288  the stream are deflateReset or deflateEnd.
289 
290  Z_FINISH can be used immediately after deflateInit if all the
291  compression is to be done in a single step. In this case, avail_out must
292  be at least the value returned by deflateBound (see below). If deflate
293  does not return Z_STREAM_END, then it must be called again as described
294  above.
295 
296  deflate() sets strm->adler to the adler32 checksum of all input read
297  so far (that is, total_in bytes).
298 
299  deflate() may update strm->data_type if it can make a good guess about
300  the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
301  binary. This field is only for information purposes and does not affect
302  the compression algorithm in any manner.
303 
304  deflate() returns Z_OK if some progress has been made (more input
305  processed or more output produced), Z_STREAM_END if all input has been
306  consumed and all output has been produced (only when flush is set to
307  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for
308  example if next_in or next_out was nullptr), Z_BUF_ERROR if no progress is
309  possible (for example avail_in or avail_out was zero). Note that
310  Z_BUF_ERROR is not fatal, and deflate() can be called again with more
311  input and more output space to continue compressing.
312  */
313 
314  ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
315  /*
316  All dynamically allocated data structures for this stream are freed.
317  This function discards any unprocessed input and does not flush any
318  pending output.
319 
320  deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
321  stream state was inconsistent, Z_DATA_ERROR if the stream was freed
322  prematurely (some input or output was discarded). In the error case,
323  msg may be set but then points to a static string (which must not be
324  deallocated).
325  */
326 
327  /*
328  ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
329 
330  Initializes the internal stream state for decompression. The fields
331  next_in, avail_in, zalloc, zfree and opaque must be initialized before by
332  the caller. If next_in is not Z_NULL and avail_in is large enough (the
333  exact value depends on the compression method), inflateInit determines the
334  compression method from the zlib header and allocates all data structures
335  accordingly; otherwise the allocation will be deferred to the first call
336  of inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them
337  to use default allocation functions.
338 
339  inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
340  enough memory, Z_VERSION_ERROR if the zlib library version is incompatible
341  with the version assumed by the caller. msg is set to null if there is no
342  error message. inflateInit does not perform any decompression apart from
343  reading the zlib header if present: this will be done by inflate(). (So
344  next_in and avail_in may be modified, but next_out and avail_out are
345  unchanged.)
346  */
347 
348  ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
349  /*
350  inflate decompresses as much data as possible, and stops when the input
351  buffer becomes empty or the output buffer becomes full. It may introduce
352  some output latency (reading input without producing any output) except
353  when forced to flush.
354 
355  The detailed semantics are as follows. inflate performs one or both of the
356  following actions:
357 
358  - Decompress more input starting at next_in and update next_in and
359  avail_in accordingly. If not all input can be processed (because there is
360  not enough room in the output buffer), next_in is updated and processing
361  will resume at this point for the next call of inflate().
362 
363  - Provide more output starting at next_out and update next_out and
364  avail_out accordingly. inflate() provides as much output as possible,
365  until there is no more input data or no more space in the output buffer
366  (see below about the flush parameter).
367 
368  Before the call of inflate(), the application should ensure that at least
369  one of the actions is possible, by providing more input and/or consuming
370  more output, and updating the next_* and avail_* values accordingly.
371  The application can consume the uncompressed output when it wants, for
372  example when the output buffer is full (avail_out == 0), or after each
373  call of inflate(). If inflate returns Z_OK and with zero avail_out, it
374  must be called again after making room in the output buffer because there
375  might be more output pending.
376 
377  The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
378  Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
379  output as possible to the output buffer. Z_BLOCK requests that inflate()
380  stop if and when it gets to the next deflate block boundary. When decoding
381  the zlib or gzip format, this will cause inflate() to return immediately
382  after the header and before the first block. When doing a raw inflate,
383  inflate() will go ahead and process the first block, and will return when
384  it gets to the end of that block, or when it runs out of data.
385 
386  The Z_BLOCK option assists in appending to or combining deflate streams.
387  Also to assist in this, on return inflate() will set strm->data_type to
388  the number of unused bits in the last byte taken from strm->next_in, plus
389  64 if inflate() is currently decoding the last block in the deflate
390  stream, plus 128 if inflate() returned immediately after decoding an
391  end-of-block code or decoding the complete header up to just before the
392  first byte of the deflate stream. The end-of-block will not be indicated
393  until all of the uncompressed data from that block has been written to
394  strm->next_out. The number of unused bits may in general be greater than
395  seven, except when bit 7 of data_type is set, in which case the number of
396  unused bits will be less than eight.
397 
398  inflate() should normally be called until it returns Z_STREAM_END or an
399  error. However if all decompression is to be performed in a single step
400  (a single call of inflate), the parameter flush should be set to
401  Z_FINISH. In this case all pending input is processed and all pending
402  output is flushed; avail_out must be large enough to hold all the
403  uncompressed data. (The size of the uncompressed data may have been saved
404  by the compressor for this purpose.) The next operation on this stream
405  must be inflateEnd to deallocate the decompression state. The use of
406  Z_FINISH is never required, but can be used to inform inflate that a
407  faster approach may be used for the single inflate() call.
408 
409  In this implementation, inflate() always flushes as much output as
410  possible to the output buffer, and always uses the faster approach on the
411  first call. So the only effect of the flush parameter in this
412  implementation is on the return value of inflate(), as noted below, or
413  when it returns early because Z_BLOCK is used.
414 
415  If a preset dictionary is needed after this call (see
416  inflateSetDictionary below), inflate sets strm->adler to the adler32
417  checksum of the dictionary chosen by the compressor and returns
418  Z_NEED_DICT; otherwise it sets strm->adler to the adler32 checksum of all
419  output produced so far (that is, total_out bytes) and returns Z_OK,
420  Z_STREAM_END or an error code as described below. At the end of the
421  stream, inflate() checks that its computed adler32 checksum is equal to
422  that saved by the compressor and returns Z_STREAM_END only if the checksum
423  is correct.
424 
425  inflate() will decompress and check either zlib-wrapped or gzip-wrapped
426  deflate data. The header type is detected automatically. Any information
427  contained in the gzip header is not retained, so applications that need
428  that information should instead use raw inflate, see inflateInit2() below,
429  or inflateBack() and perform their own processing of the gzip header and
430  trailer.
431 
432  inflate() returns Z_OK if some progress has been made (more input
433  processed or more output produced), Z_STREAM_END if the end of the
434  compressed data has been reached and all uncompressed output has been
435  produced, Z_NEED_DICT if a preset dictionary is needed at this point,
436  Z_DATA_ERROR if the input data was corrupted (input stream not conforming
437  to the zlib format or incorrect check value), Z_STREAM_ERROR if the stream
438  structure was inconsistent (for example if next_in or next_out was
439  nullptr), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if no
440  progress is possible or if there was not enough room in the output buffer
441  when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and inflate()
442  can be called again with more input and more output space to continue
443  decompressing. If Z_DATA_ERROR is returned, the application may then call
444  inflateSync() to look for a good compression block if a partial recovery
445  of the data is desired.
446  */
447 
448  ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
449  /*
450  All dynamically allocated data structures for this stream are freed.
451  This function discards any unprocessed input and does not flush any
452  pending output.
453 
454  inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
455  was inconsistent. In the error case, msg may be set but then points to a
456  static string (which must not be deallocated).
457  */
458 
459  /* Advanced functions */
460 
461  /*
462  The following functions are needed only in some special applications.
463  */
464 
465  /*
466  ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
467  int level,
468  int method,
469  int windowBits,
470  int memLevel,
471  int strategy));
472 
473  This is another version of deflateInit with more compression options.
474  The fields next_in, zalloc, zfree and opaque must be initialized before by
475  the caller.
476 
477  The method parameter is the compression method. It must be Z_DEFLATED
478  in this version of the library.
479 
480  The windowBits parameter is the base two logarithm of the window size
481  (the size of the history buffer). It should be in the range 8..15 for
482  this version of the library. Larger values of this parameter result in
483  better compression at the expense of memory usage. The default value is 15
484  if deflateInit is used instead.
485 
486  windowBits can also be -8..-15 for raw deflate. In this case,
487  -windowBits determines the window size. deflate() will then generate raw
488  deflate data with no zlib header or trailer, and will not compute an adler32
489  check value.
490 
491  windowBits can also be greater than 15 for optional gzip encoding. Add
492  16 to windowBits to write a simple gzip header and trailer around the
493  compressed data instead of a zlib wrapper. The gzip header will have no
494  file name, no extra data, no comment, no modification time (set to zero),
495  no header crc, and the operating system will be set to 255 (unknown). If
496  a gzip stream is being written, strm->adler is a crc32 instead of an
497  adler32.
498 
499  The memLevel parameter specifies how much memory should be allocated
500  for the internal compression state. memLevel=1 uses minimum memory but
501  is slow and reduces compression ratio; memLevel=9 uses maximum memory
502  for optimal speed. The default value is 8. See zconf.h for total memory
503  usage as a function of windowBits and memLevel.
504 
505  The strategy parameter is used to tune the compression algorithm. Use
506  the value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced
507  by a filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only
508  (no string match), or Z_RLE to limit match distances to one (run-length
509  encoding). Filtered data consists mostly of small values with a somewhat
510  random distribution. In this case, the compression algorithm is tuned to
511  compress them better. The effect of Z_FILTERED is to force more Huffman
512  coding and less string matching; it is somewhat intermediate between
513  Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
514  Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
515  strategy parameter only affects the compression ratio but not the
516  correctness of the compressed output even if it is not set appropriately.
517  Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
518  decoder for special applications.
519 
520  deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not
521  enough memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
522  method). msg is set to null if there is no error message. deflateInit2
523  does not perform any compression: this will be done by deflate().
524  */
525 
526  ZEXTERN int ZEXPORT deflateSetDictionary
527  OF((z_streamp strm, const Bytef* dictionary, uInt dictLength));
528  /*
529  Initializes the compression dictionary from the given byte sequence
530  without producing any compressed output. This function must be called
531  immediately after deflateInit, deflateInit2 or deflateReset, before any
532  call of deflate. The compressor and decompressor must use exactly the
533  same dictionary (see inflateSetDictionary).
534 
535  The dictionary should consist of strings (byte sequences) that are
536  likely to be encountered later in the data to be compressed, with the
537  most commonly used strings preferably put towards the end of the
538  dictionary. Using a dictionary is most useful when the data to be
539  compressed is short and can be predicted with good accuracy; the data can
540  then be compressed better than with the default empty dictionary.
541 
542  Depending on the size of the compression data structures selected by
543  deflateInit or deflateInit2, a part of the dictionary may in effect be
544  discarded, for example if the dictionary is larger than the window size
545  in deflate or deflate2. Thus the strings most likely to be useful should
546  be put at the end of the dictionary, not at the front. In addition, the
547  current implementation of deflate will use at most the window size minus
548  262 bytes of the provided dictionary.
549 
550  Upon return of this function, strm->adler is set to the adler32 value
551  of the dictionary; the decompressor may later use this value to determine
552  which dictionary has been used by the compressor. (The adler32 value
553  applies to the whole dictionary even if only a subset of the dictionary
554  is actually used by the compressor.) If a raw deflate was requested, then
555  the adler32 value is not computed and strm->adler is not set.
556 
557  deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
558  parameter is invalid (such as nullptr dictionary) or the stream state is
559  inconsistent (for example if deflate has already been called for this
560  stream or if the compression method is bsort). deflateSetDictionary does
561  not perform any compression: this will be done by deflate().
562  */
563 
564  ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, z_streamp source));
565  /*
566  Sets the destination stream as a complete copy of the source stream.
567 
568  This function can be useful when several compression strategies will be
569  tried, for example when there are several ways of pre-processing the
570  input data with a filter. The streams that will be discarded should then
571  be freed by calling deflateEnd. Note that deflateCopy duplicates the
572  internal compression state which can be quite large, so this strategy is
573  slow and can consume lots of memory.
574 
575  deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
576  enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
577  (such as zalloc being nullptr). msg is left unchanged in both source and
578  destination.
579  */
580 
581  ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
582  /*
583  This function is equivalent to deflateEnd followed by deflateInit,
584  but does not free and reallocate all the internal compression state.
585  The stream will keep the same compression level and any other attributes
586  that may have been set by deflateInit2.
587 
588  deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
589  stream state was inconsistent (such as zalloc or state being nullptr).
590  */
591 
592  ZEXTERN int ZEXPORT deflateParams
593  OF((z_streamp strm, int level, int strategy));
594  /*
595  Dynamically update the compression level and compression strategy. The
596  interpretation of level and strategy is as in deflateInit2. This can be
597  used to switch between compression and straight copy of the input data,
598  or to switch to a different kind of input data requiring a different
599  strategy. If the compression level is changed, the input available so far
600  is compressed with the old level (and may be flushed); the new level will
601  take effect only at the next call of deflate().
602 
603  Before the call of deflateParams, the stream state must be set as for
604  a call of deflate(), since the currently available input may have to
605  be compressed and flushed. In particular, strm->avail_out must be
606  non-zero.
607 
608  deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
609  stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
610  if strm->avail_out was zero.
611  */
612 
613  ZEXTERN int ZEXPORT deflateTune
614  OF((z_streamp strm, int good_length, int max_lazy, int nice_length,
615  int max_chain));
616  /*
617  Fine tune deflate's internal compression parameters. This should only
618  be used by someone who understands the algorithm used by zlib's deflate
619  for searching for the best matching string, and even then only by the
620  most fanatic optimizer trying to squeeze out the last compressed bit for
621  their specific input data. Read the deflate.c source code for the
622  meaning of the max_lazy, good_length, nice_length, and max_chain
623  parameters.
624 
625  deflateTune() can be called after deflateInit() or deflateInit2(), and
626  returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
627  */
628 
629  ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, uLong sourceLen));
630  /*
631  deflateBound() returns an upper bound on the compressed size after
632  deflation of sourceLen bytes. It must be called after deflateInit()
633  or deflateInit2(). This would be used to allocate an output buffer
634  for deflation in a single pass, and so would be called before deflate().
635  */
636 
637  ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, int bits, int value));
638  /*
639  deflatePrime() inserts bits in the deflate output stream. The intent
640  is that this function is used to start off the deflate output with the
641  bits leftover from a previous deflate stream when appending to it. As
642  such, this function can only be used for raw deflate, and must be used
643  before the first deflate() call after a deflateInit2() or deflateReset().
644  bits must be less than or equal to 16, and that many of the least
645  significant bits of value will be inserted in the output.
646 
647  deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
648  stream state was inconsistent.
649  */
650 
651  ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, gz_headerp head));
652  /*
653  deflateSetHeader() provides gzip header information for when a gzip
654  stream is requested by deflateInit2(). deflateSetHeader() may be called
655  after deflateInit2() or deflateReset() and before the first call of
656  deflate(). The text, time, os, extra field, name, and comment
657  information in the provided gz_header structure are written to the gzip
658  header (xflag is ignored -- the extra flags are set according to the
659  compression level). The caller must assure that, if not Z_NULL, name and
660  comment are terminated with a zero byte, and that if extra is not Z_NULL,
661  that extra_len bytes are available there. If hcrc is true, a gzip header
662  crc is included. Note that the current versions of the command-line
663  version of gzip (up through version 1.3.x) do not support header crc's,
664  and will report that it is a "multi-part gzip file" and give up.
665 
666  If deflateSetHeader is not used, the default gzip header has text
667  false, the time set to zero, and os set to 255, with no extra, name, or
668  comment fields. The gzip header is returned to the default state by
669  deflateReset().
670 
671  deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the
672  source stream state was inconsistent.
673  */
674 
675  /*
676  ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
677  int windowBits));
678 
679  This is another version of inflateInit with an extra parameter. The
680  fields next_in, avail_in, zalloc, zfree and opaque must be initialized
681  before by the caller.
682 
683  The windowBits parameter is the base two logarithm of the maximum
684  window size (the size of the history buffer). It should be in the
685  range 8..15 for this version of the library. The default value is 15 if
686  inflateInit is used instead. windowBits must be greater than or equal to the
687  windowBits value provided to deflateInit2() while compressing, or it must be
688  equal to 15 if deflateInit2() was not used. If a compressed stream with a
689  larger window size is given as input, inflate() will return with the error
690  code Z_DATA_ERROR instead of trying to allocate a larger window.
691 
692  windowBits can also be -8..-15 for raw inflate. In this case,
693  -windowBits determines the window size. inflate() will then process raw
694  deflate data, not looking for a zlib or gzip header, not generating a check
695  value, and not looking for any check values for comparison at the end of the
696  stream. This is for use with other formats that use the deflate compressed
697  data format such as zip. Those formats provide their own check values. If a
698  custom format is developed using the raw deflate format for compressed data,
699  it is recommended that a check value such as an adler32 or a crc32 be
700  applied to the uncompressed data as is done in the zlib, gzip, and zip
701  formats. For most applications, the zlib format should be used as is. Note
702  that comments above on the use in deflateInit2() applies to the magnitude of
703  windowBits.
704 
705  windowBits can also be greater than 15 for optional gzip decoding. Add
706  32 to windowBits to enable zlib and gzip decoding with automatic header
707  detection, or add 16 to decode only the gzip format (the zlib format will
708  return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler
709  is a crc32 instead of an adler32.
710 
711  inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not
712  enough memory, Z_STREAM_ERROR if a parameter is invalid (such as a null
713  strm). msg is set to null if there is no error message. inflateInit2 does
714  not perform any decompression apart from reading the zlib header if present:
715  this will be done by inflate(). (So next_in and avail_in may be modified,
716  but next_out and avail_out are unchanged.)
717  */
718 
719  ZEXTERN int ZEXPORT inflateSetDictionary
720  OF((z_streamp strm, const Bytef* dictionary, uInt dictLength));
721  /*
722  Initializes the decompression dictionary from the given uncompressed
723  byte sequence. This function must be called immediately after a call of
724  inflate, if that call returned Z_NEED_DICT. The dictionary chosen by the
725  compressor can be determined from the adler32 value returned by that call
726  of inflate. The compressor and decompressor must use exactly the same
727  dictionary (see deflateSetDictionary). For raw inflate, this function
728  can be called immediately after inflateInit2() or inflateReset() and
729  before any call of inflate() to set the dictionary. The application must
730  insure that the dictionary that was used for compression is provided.
731 
732  inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
733  parameter is invalid (such as nullptr dictionary) or the stream state is
734  inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
735  expected one (incorrect adler32 value). inflateSetDictionary does not
736  perform any decompression: this will be done by subsequent calls of
737  inflate().
738  */
739 
740  ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
741  /*
742  Skips invalid compressed data until a full flush point (see above the
743  description of deflate with Z_FULL_FLUSH) can be found, or until all
744  available input is skipped. No output is provided.
745 
746  inflateSync returns Z_OK if a full flush point has been found,
747  Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
748  has been found, or Z_STREAM_ERROR if the stream structure was
749  inconsistent. In the success case, the application may save the current
750  current value of total_in which indicates where valid compressed data was
751  found. In the error case, the application may repeatedly call inflateSync,
752  providing more input each time, until success or end of the input data.
753  */
754 
755  ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, z_streamp source));
756  /*
757  Sets the destination stream as a complete copy of the source stream.
758 
759  This function can be useful when randomly accessing a large stream. The
760  first pass through the stream can periodically record the inflate state,
761  allowing restarting inflate at those points when randomly accessing the
762  stream.
763 
764  inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
765  enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
766  (such as zalloc being nullptr). msg is left unchanged in both source and
767  destination.
768  */
769 
770  ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
771  /*
772  This function is equivalent to inflateEnd followed by inflateInit,
773  but does not free and reallocate all the internal decompression state.
774  The stream will keep attributes that may have been set by inflateInit2.
775 
776  inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
777  stream state was inconsistent (such as zalloc or state being nullptr).
778  */
779 
780  ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, int bits, int value));
781  /*
782  This function inserts bits in the inflate input stream. The intent is
783  that this function is used to start inflating at a bit position in the
784  middle of a byte. The provided bits will be used before any bytes are
785  used from next_in. This function should only be used with raw inflate,
786  and should be used before the first inflate() call after inflateInit2() or
787  inflateReset(). bits must be less than or equal to 16, and that many of
788  the least significant bits of value will be inserted in the input.
789 
790  inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
791  stream state was inconsistent.
792  */
793 
794  ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, gz_headerp head));
795  /*
796  inflateGetHeader() requests that gzip header information be stored in
797  the provided gz_header structure. inflateGetHeader() may be called after
798  inflateInit2() or inflateReset(), and before the first call of inflate().
799  As inflate() processes the gzip stream, head->done is zero until the
800  header is completed, at which time head->done is set to one. If a zlib
801  stream is being decoded, then head->done is set to -1 to indicate that
802  there will be no gzip header information forthcoming. Note that Z_BLOCK
803  can be used to force inflate() to return immediately after header
804  processing is complete and before any actual data is decompressed.
805 
806  The text, time, xflags, and os fields are filled in with the gzip
807  header contents. hcrc is set to true if there is a header CRC. (The
808  header CRC was valid if done is set to one.) If extra is not Z_NULL,
809  then extra_max contains the maximum number of bytes to write to extra.
810  Once done is true, extra_len contains the actual extra field length, and
811  extra contains the extra field, or that field truncated if extra_max is
812  less than extra_len. If name is not Z_NULL, then up to name_max
813  characters are written there, terminated with a zero unless the length is
814  greater than name_max. If comment is not Z_NULL, then up to comm_max
815  characters are written there, terminated with a zero unless the length is
816  greater than comm_max. When any of extra, name, or comment are not
817  Z_NULL and the respective field is not present in the header, then that
818  field is set to Z_NULL to signal its absence. This allows the use of
819  deflateSetHeader() with the returned structure to duplicate the header.
820  However if those fields are set to allocated memory, then the application
821  will need to save those pointers elsewhere so that they can be eventually
822  freed.
823 
824  If inflateGetHeader is not used, then the header information is simply
825  discarded. The header is always checked for validity, including the
826  header CRC if present. inflateReset() will reset the process to discard
827  the header information. The application would need to call
828  inflateGetHeader() again to retrieve the header from the next gzip
829  stream.
830 
831  inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the
832  source stream state was inconsistent.
833  */
834 
835  /*
836  ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
837  unsigned char FAR *window));
838 
839  Initialize the internal stream state for decompression using
840  inflateBack() calls. The fields zalloc, zfree and opaque in strm must be
841  initialized before the call. If zalloc and zfree are Z_NULL, then the
842  default library- derived memory allocation routines are used. windowBits is
843  the base two logarithm of the window size, in the range 8..15. window is a
844  caller supplied buffer of that size. Except for special applications where
845  it is assured that deflate was used with small window sizes, windowBits must
846  be 15 and a 32K byte window must be supplied to be able to decompress
847  general deflate streams.
848 
849  See inflateBack() for the usage of these routines.
850 
851  inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
852  the paramaters are invalid, Z_MEM_ERROR if the internal state could not
853  be allocated, or Z_VERSION_ERROR if the version of the library does not
854  match the version of the header file.
855  */
856 
857  typedef unsigned(*in_func) OF((void FAR*, unsigned char FAR* FAR*));
858  typedef int(*out_func) OF((void FAR*, unsigned char FAR*, unsigned));
859 
860  ZEXTERN int ZEXPORT inflateBack
861  OF((z_streamp strm, in_func in, void FAR* in_desc, out_func out,
862  void FAR* out_desc));
863  /*
864  inflateBack() does a raw inflate with a single call using a call-back
865  interface for input and output. This is more efficient than inflate()
866  for file i/o applications in that it avoids copying between the output
867  and the sliding window by simply making the window itself the output
868  buffer. This function trusts the application to not change the output
869  buffer passed by the output function, at least until inflateBack()
870  returns.
871 
872  inflateBackInit() must be called first to allocate the internal state
873  and to initialize the state with the user-provided window buffer.
874  inflateBack() may then be used multiple times to inflate a complete, raw
875  deflate stream with each call. inflateBackEnd() is then called to free
876  the allocated state.
877 
878  A raw deflate stream is one with no zlib or gzip header or trailer.
879  This routine would normally be used in a utility that reads zip or gzip
880  files and writes out uncompressed files. The utility would decode the
881  header and process the trailer on its own, hence this routine expects
882  only the raw deflate stream to decompress. This is different from the
883  normal behavior of inflate(), which expects either a zlib or gzip header
884  and trailer around the deflate stream.
885 
886  inflateBack() uses two subroutines supplied by the caller that are then
887  called by inflateBack() for input and output. inflateBack() calls those
888  routines until it reads a complete deflate stream and writes out all of
889  the uncompressed data, or until it encounters an error. The function's
890  parameters and return types are defined above in the in_func and out_func
891  typedefs. inflateBack() will call in(in_desc, &buf) which should return
892  the number of bytes of provided input, and a pointer to that input in
893  buf. If there is no input available, in() must return zero--buf is
894  ignored in that case--and inflateBack() will return a buffer error.
895  inflateBack() will call out(out_desc, buf, len) to write the uncompressed
896  data buf[0..len-1]. out() should return zero on success, or non-zero on
897  failure. If out() returns non-zero, inflateBack() will return with an
898  error. Neither in() nor out() are permitted to change the contents of
899  the window provided to inflateBackInit(), which is also the buffer that
900  out() uses to write from. The length written by out() will be at most the
901  window size. Any non-zero amount of input may be provided by in().
902 
903  For convenience, inflateBack() can be provided input on the first call
904  by setting strm->next_in and strm->avail_in. If that input is exhausted,
905  then in() will be called. Therefore strm->next_in must be initialized
906  before calling inflateBack(). If strm->next_in is Z_NULL, then in() will
907  be called immediately for input. If strm->next_in is not Z_NULL, then
908  strm->avail_in must also be initialized, and then if strm->avail_in is
909  not zero, input will initially be taken from strm->next_in[0 ..
910  strm->avail_in - 1].
911 
912  The in_desc and out_desc parameters of inflateBack() is passed as the
913  first parameter of in() and out() respectively when they are called.
914  These descriptors can be optionally used to pass any information that the
915  caller- supplied in() and out() functions need to do their job.
916 
917  On return, inflateBack() will set strm->next_in and strm->avail_in to
918  pass back any unused input that was provided by the last in() call. The
919  return values of inflateBack() can be Z_STREAM_END on success,
920  Z_BUF_ERROR if in() or out() returned an error, Z_DATA_ERROR if there was
921  a format error in the deflate stream (in which case strm->msg is set to
922  indicate the nature of the error), or Z_STREAM_ERROR if the stream was
923  not properly initialized. In the case of Z_BUF_ERROR, an input or output
924  error can be distinguished using strm->next_in which will be Z_NULL only
925  if in() returned an error. If strm->next is not Z_NULL, then the
926  Z_BUF_ERROR was due to out() returning non-zero. (in() will always be
927  called before out(), so strm->next_in is assured to be defined if out()
928  returns non-zero.) Note that inflateBack() cannot return Z_OK.
929  */
930 
931  ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
932  /*
933  All memory allocated by inflateBackInit() is freed.
934 
935  inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the
936  stream state was inconsistent.
937  */
938 
939  ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
940  /* Return flags indicating compile-time options.
941 
942  Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
943  1.0: size of uInt
944  3.2: size of uLong
945  5.4: size of voidpf (pointer)
946  7.6: size of z_off_t
947 
948  Compiler, assembler, and debug options:
949  8: DEBUG
950  9: ASMV or ASMINF -- use ASM code
951  10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
952  11: 0 (reserved)
953 
954  One-time table building (smaller code, but not thread-safe if true):
955  12: BUILDFIXED -- build static block decoding tables when needed
956  13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
957  14,15: 0 (reserved)
958 
959  Library content (indicates missing functionality):
960  16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
961  deflate code when not needed)
962  17: NO_GZIP -- deflate can't write gzip streams, and inflate can't
963  detect and decode gzip streams (to avoid linking crc code) 18-19: 0
964  (reserved)
965 
966  Operation variations (changes in library functionality):
967  20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
968  21: FASTEST -- deflate algorithm with only one, lowest compression
969  level 22,23: 0 (reserved)
970 
971  The sprintf variant used by gzprintf (zero is best):
972  24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
973  25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
974  26: 0 = returns value, 1 = void -- 1 means inferred string length
975  returned
976 
977  Remainder:
978  27-31: 0 (reserved)
979  */
980 
981  /* utility functions */
982 
983  /*
984  The following utility functions are implemented on top of the
985  basic stream-oriented functions. To simplify the interface, some
986  default options are assumed (compression level and memory usage,
987  standard memory allocation functions). The source code of these
988  utility functions can easily be modified if you need special options.
989  */
990 
992  (Bytef * dest, uLongf* destLen, const Bytef* source, uLong sourceLen));
993  /*
994  Compresses the source buffer into the destination buffer. sourceLen is
995  the byte length of the source buffer. Upon entry, destLen is the total
996  size of the destination buffer, which must be at least the value returned
997  by compressBound(sourceLen). Upon exit, destLen is the actual size of the
998  compressed buffer.
999  This function can be used to compress a whole file at once if the
1000  input file is mmap'ed.
1001  compress returns Z_OK if success, Z_MEM_ERROR if there was not
1002  enough memory, Z_BUF_ERROR if there was not enough room in the output
1003  buffer.
1004  */
1005 
1006  ZEXTERN int ZEXPORT compress2
1007  OF((Bytef * dest, uLongf* destLen, const Bytef* source, uLong sourceLen,
1008  int level));
1009  /*
1010  Compresses the source buffer into the destination buffer. The level
1011  parameter has the same meaning as in deflateInit. sourceLen is the byte
1012  length of the source buffer. Upon entry, destLen is the total size of the
1013  destination buffer, which must be at least the value returned by
1014  compressBound(sourceLen). Upon exit, destLen is the actual size of the
1015  compressed buffer.
1016 
1017  compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
1018  memory, Z_BUF_ERROR if there was not enough room in the output buffer,
1019  Z_STREAM_ERROR if the level parameter is invalid.
1020  */
1021 
1022  ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
1023  /*
1024  compressBound() returns an upper bound on the compressed size after
1025  compress() or compress2() on sourceLen bytes. It would be used before
1026  a compress() or compress2() call to allocate the destination buffer.
1027  */
1028 
1029  ZEXTERN int ZEXPORT uncompress OF(
1030  (Bytef * dest, uLongf* destLen, const Bytef* source, uLong sourceLen));
1031  /*
1032  Decompresses the source buffer into the destination buffer. sourceLen
1033  is the byte length of the source buffer. Upon entry, destLen is the total
1034  size of the destination buffer, which must be large enough to hold the
1035  entire uncompressed data. (The size of the uncompressed data must have
1036  been saved previously by the compressor and transmitted to the
1037  decompressor by some mechanism outside the scope of this compression
1038  library.) Upon exit, destLen is the actual size of the compressed buffer.
1039  This function can be used to decompress a whole file at once if the
1040  input file is mmap'ed.
1041 
1042  uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
1043  enough memory, Z_BUF_ERROR if there was not enough room in the output
1044  buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
1045  */
1046 
1047  typedef voidp gzFile;
1048 
1049  ZEXTERN gzFile ZEXPORT gzopen OF((const char* path, const char* mode));
1050  /*
1051  Opens a gzip (.gz) file for reading or writing. The mode parameter
1052  is as in fopen ("rb" or "wb") but can also include a compression level
1053  ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
1054  Huffman only compression as in "wb1h", or 'R' for run-length encoding
1055  as in "wb1R". (See the description of deflateInit2 for more information
1056  about the strategy parameter.)
1057 
1058  gzopen can be used to read a file which is not in gzip format; in this
1059  case gzread will directly read from the file without decompression.
1060 
1061  gzopen returns nullptr if the file could not be opened or if there was
1062  insufficient memory to allocate the (de)compression state; errno
1063  can be checked to distinguish the two cases (if errno is zero, the
1064  zlib error is Z_MEM_ERROR). */
1065 
1066  ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char* mode));
1067  /*
1068  gzdopen() associates a gzFile with the file descriptor fd. File
1069  descriptors are obtained from calls like open, dup, creat, pipe or
1070  fileno (in the file has been previously opened with fopen).
1071  The mode parameter is as in gzopen.
1072  The next call of gzclose on the returned gzFile will also close the
1073  file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
1074  descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
1075  gzdopen returns nullptr if there was insufficient memory to allocate
1076  the (de)compression state.
1077  */
1078 
1079  ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1080  /*
1081  Dynamically update the compression level or strategy. See the
1082  description of deflateInit2 for the meaning of these parameters.
1083  gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was
1084  not opened for writing.
1085  */
1086 
1087  ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
1088  /*
1089  Reads the given number of uncompressed bytes from the compressed file.
1090  If the input file was not in gzip format, gzread copies the given number
1091  of bytes into the buffer.
1092  gzread returns the number of uncompressed bytes actually read (0 for
1093  end of file, -1 for error). */
1094 
1095  ZEXTERN int ZEXPORT gzwrite OF((gzFile file, voidpc buf, unsigned len));
1096  /*
1097  Writes the given number of uncompressed bytes into the compressed file.
1098  gzwrite returns the number of uncompressed bytes actually written
1099  (0 in case of error).
1100  */
1101 
1102  ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char* format, ...));
1103  /*
1104  Converts, formats, and writes the args to the compressed file under
1105  control of the format string, as in fprintf. gzprintf returns the number
1106  of uncompressed bytes actually written (0 in case of error). The number
1107  of uncompressed bytes written is limited to 4095. The caller should
1108  assure that this limit is not exceeded. If it is exceeded, then
1109  gzprintf() will return return an error (0) with nothing written. In this
1110  case, there may also be a buffer overflow with unpredictable
1111  consequences, which is possible only if zlib was compiled with the
1112  insecure functions sprintf() or vsprintf() because the secure snprintf()
1113  or vsnprintf() functions were not available.
1114  */
1115 
1116  ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char* s));
1117  /*
1118  Writes the given null-terminated string to the compressed file,
1119  excluding the terminating null character. gzputs returns the number of
1120  characters written, or -1 in case of error.
1121  */
1122 
1123  ZEXTERN char* ZEXPORT gzgets OF((gzFile file, char* buf, int len));
1124  /*
1125  Reads bytes from the compressed file until len-1 characters are read,
1126  or a newline character is read and transferred to buf, or an end-of-file
1127  condition is encountered. The string is then terminated with a null
1128  character.
1129  gzgets returns buf, or Z_NULL in case of error.
1130  */
1131 
1132  ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
1133  /*
1134  Writes c, converted to an unsigned char, into the compressed file.
1135  gzputc returns the value that was written, or -1 in case of error.
1136  */
1137 
1138  ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
1139  /*
1140  Reads one byte from the compressed file. gzgetc returns this byte
1141  or -1 in case of end of file or error.
1142  */
1143 
1144  ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
1145  /*
1146  Push one character back onto the stream to be read again later.
1147  Only one character of push-back is allowed. gzungetc() returns the
1148  character pushed, or -1 on failure. gzungetc() will fail if a
1149  character has been pushed but not read yet, or if c is -1. The pushed
1150  character will be discarded if the stream is repositioned with gzseek()
1151  or gzrewind().
1152  */
1153 
1154  ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
1155  /*
1156  Flushes all pending output into the compressed file. The parameter
1157  flush is as in the deflate() function. The return value is the zlib
1158  error number (see function gzerror below). gzflush returns Z_OK if
1159  the flush parameter is Z_FINISH and all output could be flushed.
1160  gzflush should be called only when strictly necessary because it can
1161  degrade compression.
1162  */
1163 
1164  ZEXTERN z_off_t ZEXPORT gzseek
1165  OF((gzFile file, z_off_t offset, int whence));
1166  /*
1167  Sets the starting position for the next gzread or gzwrite on the
1168  given compressed file. The offset represents a number of bytes in the
1169  uncompressed data stream. The whence parameter is defined as in lseek(2);
1170  the value SEEK_END is not supported.
1171  If the file is opened for reading, this function is emulated but can be
1172  extremely slow. If the file is opened for writing, only forward seeks are
1173  supported; gzseek then compresses a sequence of zeroes up to the new
1174  starting position.
1175 
1176  gzseek returns the resulting offset location as measured in bytes from
1177  the beginning of the uncompressed stream, or -1 in case of error, in
1178  particular if the file is opened for writing and the new starting
1179  position would be before the current position.
1180  */
1181 
1182  ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
1183  /*
1184  Rewinds the given file. This function is supported only for reading.
1185 
1186  gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1187  */
1188 
1189  ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
1190  /*
1191  Returns the starting position for the next gzread or gzwrite on the
1192  given compressed file. This position represents a number of bytes in the
1193  uncompressed data stream.
1194 
1195  gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1196  */
1197 
1198  ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1199  /*
1200  Returns 1 when EOF has previously been detected reading the given
1201  input stream, otherwise zero.
1202  */
1203 
1204  ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
1205  /*
1206  Returns 1 if file is being read directly without decompression,
1207  otherwise zero.
1208  */
1209 
1210  ZEXTERN int ZEXPORT gzclose OF((gzFile file));
1211  /*
1212  Flushes all pending output if necessary, closes the compressed file
1213  and deallocates all the (de)compression state. The return value is the
1214  zlib error number (see function gzerror below).
1215  */
1216 
1217  ZEXTERN const char* ZEXPORT gzerror OF((gzFile file, int* errnum));
1218  /*
1219  Returns the error message for the last error which occurred on the
1220  given compressed file. errnum is set to zlib error number. If an
1221  error occurred in the file system and not in the compression library,
1222  errnum is set to Z_ERRNO and the application may consult errno
1223  to get the exact error code.
1224  */
1225 
1226  ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1227  /*
1228  Clears the error and end-of-file flags for file. This is analogous to
1229  the clearerr() function in stdio. This is useful for continuing to read a
1230  gzip file that is being written concurrently.
1231  */
1232 
1233  /* checksum functions */
1234 
1235  /*
1236  These functions are not related to compression but are exported
1237  anyway because they might be useful in applications using the
1238  compression library.
1239  */
1240 
1241  ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef* buf, uInt len));
1242  /*
1243  Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1244  return the updated checksum. If buf is nullptr, this function returns
1245  the required initial value for the checksum.
1246  An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
1247  much faster. Usage example:
1248 
1249  uLong adler = adler32(0L, Z_NULL, 0);
1250 
1251  while (read_buffer(buffer, length) != EOF) {
1252  adler = adler32(adler, buffer, length);
1253  }
1254  if (adler != original_adler) error();
1255  */
1256 
1257  ZEXTERN uLong ZEXPORT adler32_combine
1258  OF((uLong adler1, uLong adler2, z_off_t len2));
1259  /*
1260  Combine two Adler-32 checksums into one. For two sequences of bytes,
1261  seq1 and seq2 with lengths len1 and len2, Adler-32 checksums were
1262  calculated for each, adler1 and adler2. adler32_combine() returns the
1263  Adler-32 checksum of seq1 and seq2 concatenated, requiring only adler1,
1264  adler2, and len2.
1265  */
1266 
1267  ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef* buf, uInt len));
1268  /*
1269  Update a running CRC-32 with the bytes buf[0..len-1] and return the
1270  updated CRC-32. If buf is nullptr, this function returns the required
1271  initial value for the for the crc. Pre- and post-conditioning (one's
1272  complement) is performed within this function so it shouldn't be done by
1273  the application. Usage example:
1274 
1275  uLong crc = crc32(0L, Z_NULL, 0);
1276 
1277  while (read_buffer(buffer, length) != EOF) {
1278  crc = crc32(crc, buffer, length);
1279  }
1280  if (crc != original_crc) error();
1281  */
1282 
1283  ZEXTERN uLong ZEXPORT crc32_combine
1284  OF((uLong crc1, uLong crc2, z_off_t len2));
1285 
1286  /*
1287  Combine two CRC-32 check values into one. For two sequences of bytes,
1288  seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1289  calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1290  check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
1291  len2.
1292  */
1293 
1294  /* various hacks, don't look :) */
1295 
1296  /* deflateInit and inflateInit are macros to allow checking the zlib version
1297  * and the compiler's view of z_stream:
1298  */
1299  ZEXTERN int ZEXPORT deflateInit_
1300  OF((z_streamp strm, int level, const char* version, int stream_size));
1301  ZEXTERN int ZEXPORT inflateInit_
1302  OF((z_streamp strm, const char* version, int stream_size));
1303  ZEXTERN int ZEXPORT deflateInit2_
1304  OF((z_streamp strm, int level, int method, int windowBits, int memLevel,
1305  int strategy, const char* version, int stream_size));
1306  ZEXTERN int ZEXPORT inflateInit2_ OF(
1307  (z_streamp strm, int windowBits, const char* version, int stream_size));
1308  ZEXTERN int ZEXPORT inflateBackInit_
1309  OF((z_streamp strm, int windowBits, unsigned char FAR* window,
1310  const char* version, int stream_size));
1311 #define deflateInit(strm, level) \
1312  deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
1313 #define inflateInit(strm) inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
1314 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
1315  deflateInit2_( \
1316  (strm), (level), (method), (windowBits), (memLevel), (strategy), \
1317  ZLIB_VERSION, sizeof(z_stream))
1318 #define inflateInit2(strm, windowBits) \
1319  inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1320 #define inflateBackInit(strm, windowBits, window) \
1321  inflateBackInit_( \
1322  (strm), (windowBits), (window), ZLIB_VERSION, sizeof(z_stream))
1323 
1324 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
1325  struct internal_state
1326  {
1327  int dummy;
1328  }; /* hack for buggy compilers */
1329 #endif
1330 
1331  ZEXTERN const char* ZEXPORT zError OF((int));
1332  ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z));
1333  ZEXTERN const uLongf* ZEXPORT get_crc_table OF((void));
1334 
1335 #ifdef __cplusplus
1336 }
1337 #endif
int xflags
Definition: zlib.h:96
Bytef * extra
Definition: zlib.h:98
GLdouble GLdouble z
Definition: glext.h:3879
int text
Definition: zlib.h:94
Bytef * next_in
Definition: zlib.h:66
voidpf alloc_func OF((voidpf opaque, uInt items, uInt size))
Definition: zlib.h:59
int hcrc
Definition: zlib.h:105
uLong time
Definition: zlib.h:95
#define z_off_t
Definition: zconf.h:305
uInt avail_in
Definition: zlib.h:67
GLintptr offset
Definition: glext.h:3936
Bytef * name
Definition: zlib.h:101
uInt extra_max
Definition: zlib.h:100
char * msg
Definition: zlib.h:74
uInt name_max
Definition: zlib.h:102
int done
Definition: zlib.h:106
unsigned long uLong
Definition: zconf.h:268
struct gz_header_s gz_header
gz_header FAR * gz_headerp
Definition: zlib.h:110
GLdouble s
Definition: glext.h:3682
GLenum GLsizei len
Definition: glext.h:4756
Byte FAR Bytef
Definition: zconf.h:274
voidpf opaque
Definition: zlib.h:79
struct internal_state FAR * state
Definition: zlib.h:75
voidp gzFile
Definition: zlib.h:1047
free_func zfree
Definition: zlib.h:78
void * voidp
Definition: zconf.h:284
uLong reserved
Definition: zlib.h:83
uInt extra_len
Definition: zlib.h:99
const GLubyte * c
Definition: glext.h:6406
int data_type
Definition: zlib.h:81
int os
Definition: zlib.h:97
uLong total_in
Definition: zlib.h:68
alloc_func zalloc
Definition: zlib.h:77
Bytef * next_out
Definition: zlib.h:70
GLint mode
Definition: glext.h:5753
Bytef * comment
Definition: zlib.h:103
uLong adler
Definition: zlib.h:82
mrpt::vision::TStereoCalibResults out
uLong total_out
Definition: zlib.h:72
void const * voidpc
Definition: zconf.h:282
#define ZEXTERN
Definition: zconf.h:251
uLong FAR uLongf
Definition: zconf.h:279
GLuint in
Definition: glext.h:7391
GLint level
Definition: glext.h:3606
GLsizei GLsizei GLchar * source
Definition: glext.h:4097
uInt comm_max
Definition: zlib.h:104
GLuint address
Definition: glext.h:7060
uInt avail_out
Definition: zlib.h:71
typedef void(APIENTRYP PFNGLBLENDCOLORPROC)(GLclampf red
GLenum GLsizei GLenum format
Definition: glext.h:3535
GLsizei const GLfloat * value
Definition: glext.h:4134
GLsizeiptr size
Definition: glext.h:3934
struct z_stream_s z_stream
#define FAR
Definition: zconf.h:261
z_stream FAR * z_streamp
Definition: zlib.h:86
void compress(void *inData, size_t inDataSize, std::vector< unsigned char > &outData)
Compress an array of bytes into another one.
Definition: zip.cpp:35
void FAR * voidpf
Definition: zconf.h:283
#define ZEXPORT
Definition: zconf.h:254
#define ZEXPORTVA
Definition: zconf.h:257
unsigned int uInt
Definition: zconf.h:267



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