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00001 /* zlib.h -- interface of the 'zlib' general purpose compression library
00002   version 1.2.2, October 3rd, 2004
00003 
00004   Copyright (C) 1995-2004 Jean-loup Gailly and Mark Adler
00005 
00006   This software is provided 'as-is', without any express or implied
00007   warranty.  In no event will the authors be held liable for any damages
00008   arising from the use of this software.
00009 
00010   Permission is granted to anyone to use this software for any purpose,
00011   including commercial applications, and to alter it and redistribute it
00012   freely, subject to the following restrictions:
00013 
00014   1. The origin of this software must not be misrepresented; you must not
00015      claim that you wrote the original software. If you use this software
00016      in a product, an acknowledgment in the product documentation would be
00017      appreciated but is not required.
00018   2. Altered source versions must be plainly marked as such, and must not be
00019      misrepresented as being the original software.
00020   3. This notice may not be removed or altered from any source distribution.
00021 
00022   Jean-loup Gailly        Mark Adler
00023   jloup@gzip.org          madler@alumni.caltech.edu
00024 
00025 
00026   The data format used by the zlib library is described by RFCs (Request for
00027   Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
00028   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
00029 */
00030 
00031 #ifndef ZLIB_H
00032 #define ZLIB_H
00033 
00034 #include "zconf.h"
00035 
00036 #ifdef __cplusplus
00037 extern "C" {
00038 #endif
00039 
00040 #define ZLIB_VERSION "1.2.2"
00041 #define ZLIB_VERNUM 0x1220
00042 
00043 #ifdef QT_MAKEDLL
00044 #define Q_ZEXPORT __declspec(dllexport)
00045 #else
00046 #if defined(QT_DLL) && !defined(QT_PLUGIN)
00047 #define Q_ZEXPORT __declspec(dllimport)
00048 #else
00049 #define Q_ZEXPORT ZEXPORT
00050 #endif
00051 #endif
00052 #ifdef Q_OS_TEMP
00053 #include <qfunctions_wce.h>
00054 #endif
00055 
00056 /*
00057      The 'zlib' compression library provides in-memory compression and
00058   decompression functions, including integrity checks of the uncompressed
00059   data.  This version of the library supports only one compression method
00060   (deflation) but other algorithms will be added later and will have the same
00061   stream interface.
00062 
00063      Compression can be done in a single step if the buffers are large
00064   enough (for example if an input file is mmap'ed), or can be done by
00065   repeated calls of the compression function.  In the latter case, the
00066   application must provide more input and/or consume the output
00067   (providing more output space) before each call.
00068 
00069      The compressed data format used by default by the in-memory functions is
00070   the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
00071   around a deflate stream, which is itself documented in RFC 1951.
00072 
00073      The library also supports reading and writing files in gzip (.gz) format
00074   with an interface similar to that of stdio using the functions that start
00075   with "gz".  The gzip format is different from the zlib format.  gzip is a
00076   gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
00077 
00078      This library can optionally read and write gzip streams in memory as well.
00079 
00080      The zlib format was designed to be compact and fast for use in memory
00081   and on communications channels.  The gzip format was designed for single-
00082   file compression on file systems, has a larger header than zlib to maintain
00083   directory information, and uses a different, slower check method than zlib.
00084 
00085      The library does not install any signal handler. The decoder checks
00086   the consistency of the compressed data, so the library should never
00087   crash even in case of corrupted input.
00088 */
00089 
00090 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
00091 typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
00092 
00093 struct internal_state;
00094 
00095 typedef struct z_stream_s {
00096     Bytef    *next_in;  /* next input byte */
00097     uInt     avail_in;  /* number of bytes available at next_in */
00098     uLong    total_in;  /* total nb of input bytes read so far */
00099 
00100     Bytef    *next_out; /* next output byte should be put there */
00101     uInt     avail_out; /* remaining free space at next_out */
00102     uLong    total_out; /* total nb of bytes output so far */
00103 
00104     char     *msg;      /* last error message, NULL if no error */
00105     struct internal_state FAR *state; /* not visible by applications */
00106 
00107     alloc_func zalloc;  /* used to allocate the internal state */
00108     free_func  zfree;   /* used to free the internal state */
00109     voidpf     opaque;  /* private data object passed to zalloc and zfree */
00110 
00111     int     data_type;  /* best guess about the data type: ascii or binary */
00112     uLong   adler;      /* adler32 value of the uncompressed data */
00113     uLong   reserved;   /* reserved for future use */
00114 } z_stream;
00115 
00116 typedef z_stream FAR *z_streamp;
00117 
00118 /*
00119    The application must update next_in and avail_in when avail_in has
00120    dropped to zero. It must update next_out and avail_out when avail_out
00121    has dropped to zero. The application must initialize zalloc, zfree and
00122    opaque before calling the init function. All other fields are set by the
00123    compression library and must not be updated by the application.
00124 
00125    The opaque value provided by the application will be passed as the first
00126    parameter for calls of zalloc and zfree. This can be useful for custom
00127    memory management. The compression library attaches no meaning to the
00128    opaque value.
00129 
00130    zalloc must return Z_NULL if there is not enough memory for the object.
00131    If zlib is used in a multi-threaded application, zalloc and zfree must be
00132    thread safe.
00133 
00134    On 16-bit systems, the functions zalloc and zfree must be able to allocate
00135    exactly 65536 bytes, but will not be required to allocate more than this
00136    if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
00137    pointers returned by zalloc for objects of exactly 65536 bytes *must*
00138    have their offset normalized to zero. The default allocation function
00139    provided by this library ensures this (see zutil.c). To reduce memory
00140    requirements and avoid any allocation of 64K objects, at the expense of
00141    compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
00142 
00143    The fields total_in and total_out can be used for statistics or
00144    progress reports. After compression, total_in holds the total size of
00145    the uncompressed data and may be saved for use in the decompressor
00146    (particularly if the decompressor wants to decompress everything in
00147    a single step).
00148 */
00149 
00150                         /* constants */
00151 
00152 #define Z_NO_FLUSH      0
00153 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
00154 #define Z_SYNC_FLUSH    2
00155 #define Z_FULL_FLUSH    3
00156 #define Z_FINISH        4
00157 #define Z_BLOCK         5
00158 /* Allowed flush values; see deflate() and inflate() below for details */
00159 
00160 #define Z_OK            0
00161 #define Z_STREAM_END    1
00162 #define Z_NEED_DICT     2
00163 #define Z_ERRNO        (-1)
00164 #define Z_STREAM_ERROR (-2)
00165 #define Z_DATA_ERROR   (-3)
00166 #define Z_MEM_ERROR    (-4)
00167 #define Z_BUF_ERROR    (-5)
00168 #define Z_VERSION_ERROR (-6)
00169 /* Return codes for the compression/decompression functions. Negative
00170  * values are errors, positive values are used for special but normal events.
00171  */
00172 
00173 #define Z_NO_COMPRESSION         0
00174 #define Z_BEST_SPEED             1
00175 #define Z_BEST_COMPRESSION       9
00176 #define Z_DEFAULT_COMPRESSION  (-1)
00177 /* compression levels */
00178 
00179 #define Z_FILTERED            1
00180 #define Z_HUFFMAN_ONLY        2
00181 #define Z_RLE                 3
00182 #define Z_DEFAULT_STRATEGY    0
00183 /* compression strategy; see deflateInit2() below for details */
00184 
00185 #define Z_BINARY   0
00186 #define Z_ASCII    1
00187 #define Z_UNKNOWN  2
00188 /* Possible values of the data_type field (though see inflate()) */
00189 
00190 #define Z_DEFLATED   8
00191 /* The deflate compression method (the only one supported in this version) */
00192 
00193 #define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
00194 
00195 #define zlib_version zlibVersion()
00196 /* for compatibility with versions < 1.0.2 */
00197 
00198                         /* basic functions */
00199 
00200 ZEXTERN Q_ZEXPORT const char * zlibVersion OF((void));
00201 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
00202    If the first character differs, the library code actually used is
00203    not compatible with the zlib.h header file used by the application.
00204    This check is automatically made by deflateInit and inflateInit.
00205  */
00206 
00207 /*
00208 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
00209 
00210      Initializes the internal stream state for compression. The fields
00211    zalloc, zfree and opaque must be initialized before by the caller.
00212    If zalloc and zfree are set to Z_NULL, deflateInit updates them to
00213    use default allocation functions.
00214 
00215      The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
00216    1 gives best speed, 9 gives best compression, 0 gives no compression at
00217    all (the input data is simply copied a block at a time).
00218    Z_DEFAULT_COMPRESSION requests a default compromise between speed and
00219    compression (currently equivalent to level 6).
00220 
00221      deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
00222    enough memory, Z_STREAM_ERROR if level is not a valid compression level,
00223    Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
00224    with the version assumed by the caller (ZLIB_VERSION).
00225    msg is set to null if there is no error message.  deflateInit does not
00226    perform any compression: this will be done by deflate().
00227 */
00228 
00229 
00230 ZEXTERN int Q_ZEXPORT deflate OF((z_streamp strm, int flush));
00231 /*
00232     deflate compresses as much data as possible, and stops when the input
00233   buffer becomes empty or the output buffer becomes full. It may introduce some
00234   output latency (reading input without producing any output) except when
00235   forced to flush.
00236 
00237     The detailed semantics are as follows. deflate performs one or both of the
00238   following actions:
00239 
00240   - Compress more input starting at next_in and update next_in and avail_in
00241     accordingly. If not all input can be processed (because there is not
00242     enough room in the output buffer), next_in and avail_in are updated and
00243     processing will resume at this point for the next call of deflate().
00244 
00245   - Provide more output starting at next_out and update next_out and avail_out
00246     accordingly. This action is forced if the parameter flush is non zero.
00247     Forcing flush frequently degrades the compression ratio, so this parameter
00248     should be set only when necessary (in interactive applications).
00249     Some output may be provided even if flush is not set.
00250 
00251   Before the call of deflate(), the application should ensure that at least
00252   one of the actions is possible, by providing more input and/or consuming
00253   more output, and updating avail_in or avail_out accordingly; avail_out
00254   should never be zero before the call. The application can consume the
00255   compressed output when it wants, for example when the output buffer is full
00256   (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
00257   and with zero avail_out, it must be called again after making room in the
00258   output buffer because there might be more output pending.
00259 
00260     If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
00261   flushed to the output buffer and the output is aligned on a byte boundary, so
00262   that the decompressor can get all input data available so far. (In particular
00263   avail_in is zero after the call if enough output space has been provided
00264   before the call.)  Flushing may degrade compression for some compression
00265   algorithms and so it should be used only when necessary.
00266 
00267     If flush is set to Z_FULL_FLUSH, all output is flushed as with
00268   Z_SYNC_FLUSH, and the compression state is reset so that decompression can
00269   restart from this point if previous compressed data has been damaged or if
00270   random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
00271   the compression.
00272 
00273     If deflate returns with avail_out == 0, this function must be called again
00274   with the same value of the flush parameter and more output space (updated
00275   avail_out), until the flush is complete (deflate returns with non-zero
00276   avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
00277   avail_out is greater than six to avoid repeated flush markers due to
00278   avail_out == 0 on return.
00279 
00280     If the parameter flush is set to Z_FINISH, pending input is processed,
00281   pending output is flushed and deflate returns with Z_STREAM_END if there
00282   was enough output space; if deflate returns with Z_OK, this function must be
00283   called again with Z_FINISH and more output space (updated avail_out) but no
00284   more input data, until it returns with Z_STREAM_END or an error. After
00285   deflate has returned Z_STREAM_END, the only possible operations on the
00286   stream are deflateReset or deflateEnd.
00287 
00288     Z_FINISH can be used immediately after deflateInit if all the compression
00289   is to be done in a single step. In this case, avail_out must be at least
00290   the value returned by deflateBound (see below). If deflate does not return
00291   Z_STREAM_END, then it must be called again as described above.
00292 
00293     deflate() sets strm->adler to the adler32 checksum of all input read
00294   so far (that is, total_in bytes).
00295 
00296     deflate() may update data_type if it can make a good guess about
00297   the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
00298   binary. This field is only for information purposes and does not affect
00299   the compression algorithm in any manner.
00300 
00301     deflate() returns Z_OK if some progress has been made (more input
00302   processed or more output produced), Z_STREAM_END if all input has been
00303   consumed and all output has been produced (only when flush is set to
00304   Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
00305   if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
00306   (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
00307   fatal, and deflate() can be called again with more input and more output
00308   space to continue compressing.
00309 */
00310 
00311 
00312 ZEXTERN int Q_ZEXPORT deflateEnd OF((z_streamp strm));
00313 /*
00314      All dynamically allocated data structures for this stream are freed.
00315    This function discards any unprocessed input and does not flush any
00316    pending output.
00317 
00318      deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
00319    stream state was inconsistent, Z_DATA_ERROR if the stream was freed
00320    prematurely (some input or output was discarded). In the error case,
00321    msg may be set but then points to a static string (which must not be
00322    deallocated).
00323 */
00324 
00325 
00326 /*
00327 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
00328 
00329      Initializes the internal stream state for decompression. The fields
00330    next_in, avail_in, zalloc, zfree and opaque must be initialized before by
00331    the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
00332    value depends on the compression method), inflateInit determines the
00333    compression method from the zlib header and allocates all data structures
00334    accordingly; otherwise the allocation will be deferred to the first call of
00335    inflate.  If zalloc and zfree are set to Z_NULL, inflateInit updates them to
00336    use default allocation functions.
00337 
00338      inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
00339    memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
00340    version assumed by the caller.  msg is set to null if there is no error
00341    message. inflateInit does not perform any decompression apart from reading
00342    the zlib header if present: this will be done by inflate().  (So next_in and
00343    avail_in may be modified, but next_out and avail_out are unchanged.)
00344 */
00345 
00346 
00347 ZEXTERN int Q_ZEXPORT inflate OF((z_streamp strm, int flush));
00348 /*
00349     inflate decompresses as much data as possible, and stops when the input
00350   buffer becomes empty or the output buffer becomes full. It may introduce
00351   some output latency (reading input without producing any output) except when
00352   forced to flush.
00353 
00354   The detailed semantics are as follows. inflate performs one or both of the
00355   following actions:
00356 
00357   - Decompress more input starting at next_in and update next_in and avail_in
00358     accordingly. If not all input can be processed (because there is not
00359     enough room in the output buffer), next_in is updated and processing
00360     will resume at this point for the next call of inflate().
00361 
00362   - Provide more output starting at next_out and update next_out and avail_out
00363     accordingly.  inflate() provides as much output as possible, until there
00364     is no more input data or no more space in the output buffer (see below
00365     about the flush parameter).
00366 
00367   Before the call of inflate(), the application should ensure that at least
00368   one of the actions is possible, by providing more input and/or consuming
00369   more output, and updating the next_* and avail_* values accordingly.
00370   The application can consume the uncompressed output when it wants, for
00371   example when the output buffer is full (avail_out == 0), or after each
00372   call of inflate(). If inflate returns Z_OK and with zero avail_out, it
00373   must be called again after making room in the output buffer because there
00374   might be more output pending.
00375 
00376     The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
00377   Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
00378   output as possible to the output buffer. Z_BLOCK requests that inflate() stop
00379   if and when it get to the next deflate block boundary. When decoding the zlib
00380   or gzip format, this will cause inflate() to return immediately after the
00381   header and before the first block. When doing a raw inflate, inflate() will
00382   go ahead and process the first block, and will return when it gets to the end
00383   of that block, or when it runs out of data.
00384 
00385     The Z_BLOCK option assists in appending to or combining deflate streams.
00386   Also to assist in this, on return inflate() will set strm->data_type to the
00387   number of unused bits in the last byte taken from strm->next_in, plus 64
00388   if inflate() is currently decoding the last block in the deflate stream,
00389   plus 128 if inflate() returned immediately after decoding an end-of-block
00390   code or decoding the complete header up to just before the first byte of the
00391   deflate stream. The end-of-block will not be indicated until all of the
00392   uncompressed data from that block has been written to strm->next_out.  The
00393   number of unused bits may in general be greater than seven, except when
00394   bit 7 of data_type is set, in which case the number of unused bits will be
00395   less than eight.
00396 
00397     inflate() should normally be called until it returns Z_STREAM_END or an
00398   error. However if all decompression is to be performed in a single step
00399   (a single call of inflate), the parameter flush should be set to
00400   Z_FINISH. In this case all pending input is processed and all pending
00401   output is flushed; avail_out must be large enough to hold all the
00402   uncompressed data. (The size of the uncompressed data may have been saved
00403   by the compressor for this purpose.) The next operation on this stream must
00404   be inflateEnd to deallocate the decompression state. The use of Z_FINISH
00405   is never required, but can be used to inform inflate that a faster approach
00406   may be used for the single inflate() call.
00407 
00408      In this implementation, inflate() always flushes as much output as
00409   possible to the output buffer, and always uses the faster approach on the
00410   first call. So the only effect of the flush parameter in this implementation
00411   is on the return value of inflate(), as noted below, or when it returns early
00412   because Z_BLOCK is used.
00413 
00414      If a preset dictionary is needed after this call (see inflateSetDictionary
00415   below), inflate sets strm->adler to the adler32 checksum of the dictionary
00416   chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
00417   strm->adler to the adler32 checksum of all output produced so far (that is,
00418   total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
00419   below. At the end of the stream, inflate() checks that its computed adler32
00420   checksum is equal to that saved by the compressor and returns Z_STREAM_END
00421   only if the checksum is correct.
00422 
00423     inflate() will decompress and check either zlib-wrapped or gzip-wrapped
00424   deflate data.  The header type is detected automatically.  Any information
00425   contained in the gzip header is not retained, so applications that need that
00426   information should instead use raw inflate, see inflateInit2() below, or
00427   inflateBack() and perform their own processing of the gzip header and
00428   trailer.
00429 
00430     inflate() returns Z_OK if some progress has been made (more input processed
00431   or more output produced), Z_STREAM_END if the end of the compressed data has
00432   been reached and all uncompressed output has been produced, Z_NEED_DICT if a
00433   preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
00434   corrupted (input stream not conforming to the zlib format or incorrect check
00435   value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
00436   if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
00437   Z_BUF_ERROR if no progress is possible or if there was not enough room in the
00438   output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
00439   inflate() can be called again with more input and more output space to
00440   continue decompressing. If Z_DATA_ERROR is returned, the application may then
00441   call inflateSync() to look for a good compression block if a partial recovery
00442   of the data is desired.
00443 */
00444 
00445 
00446 ZEXTERN int Q_ZEXPORT inflateEnd OF((z_streamp strm));
00447 /*
00448      All dynamically allocated data structures for this stream are freed.
00449    This function discards any unprocessed input and does not flush any
00450    pending output.
00451 
00452      inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
00453    was inconsistent. In the error case, msg may be set but then points to a
00454    static string (which must not be deallocated).
00455 */
00456 
00457                         /* Advanced functions */
00458 
00459 /*
00460     The following functions are needed only in some special applications.
00461 */
00462 
00463 /*
00464 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
00465                                      int  level,
00466                                      int  method,
00467                                      int  windowBits,
00468                                      int  memLevel,
00469                                      int  strategy));
00470 
00471      This is another version of deflateInit with more compression options. The
00472    fields next_in, zalloc, zfree and opaque must be initialized before by
00473    the caller.
00474 
00475      The method parameter is the compression method. It must be Z_DEFLATED in
00476    this version of the library.
00477 
00478      The windowBits parameter is the base two logarithm of the window size
00479    (the size of the history buffer). It should be in the range 8..15 for this
00480    version of the library. Larger values of this parameter result in better
00481    compression at the expense of memory usage. The default value is 15 if
00482    deflateInit is used instead.
00483 
00484      windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
00485    determines the window size. deflate() will then generate raw deflate data
00486    with no zlib header or trailer, and will not compute an adler32 check value.
00487 
00488      windowBits can also be greater than 15 for optional gzip encoding. Add
00489    16 to windowBits to write a simple gzip header and trailer around the
00490    compressed data instead of a zlib wrapper. The gzip header will have no
00491    file name, no extra data, no comment, no modification time (set to zero),
00492    no header crc, and the operating system will be set to 255 (unknown).  If a
00493    gzip stream is being written, strm->adler is a crc32 instead of an adler32.
00494 
00495      The memLevel parameter specifies how much memory should be allocated
00496    for the internal compression state. memLevel=1 uses minimum memory but
00497    is slow and reduces compression ratio; memLevel=9 uses maximum memory
00498    for optimal speed. The default value is 8. See zconf.h for total memory
00499    usage as a function of windowBits and memLevel.
00500 
00501      The strategy parameter is used to tune the compression algorithm. Use the
00502    value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
00503    filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
00504    string match), or Z_RLE to limit match distances to one (run-length
00505    encoding). Filtered data consists mostly of small values with a somewhat
00506    random distribution. In this case, the compression algorithm is tuned to
00507    compress them better. The effect of Z_FILTERED is to force more Huffman
00508    coding and less string matching; it is somewhat intermediate between
00509    Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
00510    Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
00511    parameter only affects the compression ratio but not the correctness of the
00512    compressed output even if it is not set appropriately.
00513 
00514       deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
00515    memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
00516    method). msg is set to null if there is no error message.  deflateInit2 does
00517    not perform any compression: this will be done by deflate().
00518 */
00519 
00520 ZEXTERN int Q_ZEXPORT deflateSetDictionary OF((z_streamp strm,
00521                                              const Bytef *dictionary,
00522                                              uInt  dictLength));
00523 /*
00524      Initializes the compression dictionary from the given byte sequence
00525    without producing any compressed output. This function must be called
00526    immediately after deflateInit, deflateInit2 or deflateReset, before any
00527    call of deflate. The compressor and decompressor must use exactly the same
00528    dictionary (see inflateSetDictionary).
00529 
00530      The dictionary should consist of strings (byte sequences) that are likely
00531    to be encountered later in the data to be compressed, with the most commonly
00532    used strings preferably put towards the end of the dictionary. Using a
00533    dictionary is most useful when the data to be compressed is short and can be
00534    predicted with good accuracy; the data can then be compressed better than
00535    with the default empty dictionary.
00536 
00537      Depending on the size of the compression data structures selected by
00538    deflateInit or deflateInit2, a part of the dictionary may in effect be
00539    discarded, for example if the dictionary is larger than the window size in
00540    deflate or deflate2. Thus the strings most likely to be useful should be
00541    put at the end of the dictionary, not at the front.
00542 
00543      Upon return of this function, strm->adler is set to the adler32 value
00544    of the dictionary; the decompressor may later use this value to determine
00545    which dictionary has been used by the compressor. (The adler32 value
00546    applies to the whole dictionary even if only a subset of the dictionary is
00547    actually used by the compressor.) If a raw deflate was requested, then the
00548    adler32 value is not computed and strm->adler is not set.
00549 
00550      deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
00551    parameter is invalid (such as NULL dictionary) or the stream state is
00552    inconsistent (for example if deflate has already been called for this stream
00553    or if the compression method is bsort). deflateSetDictionary does not
00554    perform any compression: this will be done by deflate().
00555 */
00556 
00557 ZEXTERN int Q_ZEXPORT deflateCopy OF((z_streamp dest,
00558                                     z_streamp source));
00559 /*
00560      Sets the destination stream as a complete copy of the source stream.
00561 
00562      This function can be useful when several compression strategies will be
00563    tried, for example when there are several ways of pre-processing the input
00564    data with a filter. The streams that will be discarded should then be freed
00565    by calling deflateEnd.  Note that deflateCopy duplicates the internal
00566    compression state which can be quite large, so this strategy is slow and
00567    can consume lots of memory.
00568 
00569      deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
00570    enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
00571    (such as zalloc being NULL). msg is left unchanged in both source and
00572    destination.
00573 */
00574 
00575 ZEXTERN int Q_ZEXPORT deflateReset OF((z_streamp strm));
00576 /*
00577      This function is equivalent to deflateEnd followed by deflateInit,
00578    but does not free and reallocate all the internal compression state.
00579    The stream will keep the same compression level and any other attributes
00580    that may have been set by deflateInit2.
00581 
00582       deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
00583    stream state was inconsistent (such as zalloc or state being NULL).
00584 */
00585 
00586 ZEXTERN int Q_ZEXPORT deflateParams OF((z_streamp strm,
00587                                       int level,
00588                                       int strategy));
00589 /*
00590      Dynamically update the compression level and compression strategy.  The
00591    interpretation of level and strategy is as in deflateInit2.  This can be
00592    used to switch between compression and straight copy of the input data, or
00593    to switch to a different kind of input data requiring a different
00594    strategy. If the compression level is changed, the input available so far
00595    is compressed with the old level (and may be flushed); the new level will
00596    take effect only at the next call of deflate().
00597 
00598      Before the call of deflateParams, the stream state must be set as for
00599    a call of deflate(), since the currently available input may have to
00600    be compressed and flushed. In particular, strm->avail_out must be non-zero.
00601 
00602      deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
00603    stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
00604    if strm->avail_out was zero.
00605 */
00606 
00607 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
00608                                        uLong sourceLen));
00609 /*
00610      deflateBound() returns an upper bound on the compressed size after
00611    deflation of sourceLen bytes.  It must be called after deflateInit()
00612    or deflateInit2().  This would be used to allocate an output buffer
00613    for deflation in a single pass, and so would be called before deflate().
00614 */
00615 
00616 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
00617                                      int bits,
00618                                      int value));
00619 /*
00620      deflatePrime() inserts bits in the deflate output stream.  The intent
00621   is that this function is used to start off the deflate output with the
00622   bits leftover from a previous deflate stream when appending to it.  As such,
00623   this function can only be used for raw deflate, and must be used before the
00624   first deflate() call after a deflateInit2() or deflateReset().  bits must be
00625   less than or equal to 16, and that many of the least significant bits of
00626   value will be inserted in the output.
00627 
00628       deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
00629    stream state was inconsistent.
00630 */
00631 
00632 /*
00633 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
00634                                      int  windowBits));
00635 
00636      This is another version of inflateInit with an extra parameter. The
00637    fields next_in, avail_in, zalloc, zfree and opaque must be initialized
00638    before by the caller.
00639 
00640      The windowBits parameter is the base two logarithm of the maximum window
00641    size (the size of the history buffer).  It should be in the range 8..15 for
00642    this version of the library. The default value is 15 if inflateInit is used
00643    instead. windowBits must be greater than or equal to the windowBits value
00644    provided to deflateInit2() while compressing, or it must be equal to 15 if
00645    deflateInit2() was not used. If a compressed stream with a larger window
00646    size is given as input, inflate() will return with the error code
00647    Z_DATA_ERROR instead of trying to allocate a larger window.
00648 
00649      windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
00650    determines the window size. inflate() will then process raw deflate data,
00651    not looking for a zlib or gzip header, not generating a check value, and not
00652    looking for any check values for comparison at the end of the stream. This
00653    is for use with other formats that use the deflate compressed data format
00654    such as zip.  Those formats provide their own check values. If a custom
00655    format is developed using the raw deflate format for compressed data, it is
00656    recommended that a check value such as an adler32 or a crc32 be applied to
00657    the uncompressed data as is done in the zlib, gzip, and zip formats.  For
00658    most applications, the zlib format should be used as is. Note that comments
00659    above on the use in deflateInit2() applies to the magnitude of windowBits.
00660 
00661      windowBits can also be greater than 15 for optional gzip decoding. Add
00662    32 to windowBits to enable zlib and gzip decoding with automatic header
00663    detection, or add 16 to decode only the gzip format (the zlib format will
00664    return a Z_DATA_ERROR.  If a gzip stream is being decoded, strm->adler is
00665    a crc32 instead of an adler32.
00666 
00667      inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
00668    memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
00669    memLevel). msg is set to null if there is no error message.  inflateInit2
00670    does not perform any decompression apart from reading the zlib header if
00671    present: this will be done by inflate(). (So next_in and avail_in may be
00672    modified, but next_out and avail_out are unchanged.)
00673 */
00674 
00675 ZEXTERN int Q_ZEXPORT inflateSetDictionary OF((z_streamp strm,
00676                                              const Bytef *dictionary,
00677                                              uInt  dictLength));
00678 /*
00679      Initializes the decompression dictionary from the given uncompressed byte
00680    sequence. This function must be called immediately after a call of inflate
00681    if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
00682    can be determined from the adler32 value returned by this call of
00683    inflate. The compressor and decompressor must use exactly the same
00684    dictionary (see deflateSetDictionary).
00685 
00686      inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
00687    parameter is invalid (such as NULL dictionary) or the stream state is
00688    inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
00689    expected one (incorrect adler32 value). inflateSetDictionary does not
00690    perform any decompression: this will be done by subsequent calls of
00691    inflate().
00692 */
00693 
00694 ZEXTERN int Q_ZEXPORT inflateSync OF((z_streamp strm));
00695 /*
00696     Skips invalid compressed data until a full flush point (see above the
00697   description of deflate with Z_FULL_FLUSH) can be found, or until all
00698   available input is skipped. No output is provided.
00699 
00700     inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
00701   if no more input was provided, Z_DATA_ERROR if no flush point has been found,
00702   or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
00703   case, the application may save the current current value of total_in which
00704   indicates where valid compressed data was found. In the error case, the
00705   application may repeatedly call inflateSync, providing more input each time,
00706   until success or end of the input data.
00707 */
00708 
00709 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
00710                                     z_streamp source));
00711 /*
00712      Sets the destination stream as a complete copy of the source stream.
00713 
00714      This function can be useful when randomly accessing a large stream.  The
00715    first pass through the stream can periodically record the inflate state,
00716    allowing restarting inflate at those points when randomly accessing the
00717    stream.
00718 
00719      inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
00720    enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
00721    (such as zalloc being NULL). msg is left unchanged in both source and
00722    destination.
00723 */
00724 
00725 ZEXTERN int Q_ZEXPORT inflateReset OF((z_streamp strm));
00726 /*
00727      This function is equivalent to inflateEnd followed by inflateInit,
00728    but does not free and reallocate all the internal decompression state.
00729    The stream will keep attributes that may have been set by inflateInit2.
00730 
00731       inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
00732    stream state was inconsistent (such as zalloc or state being NULL).
00733 */
00734 
00735 /*
00736 ZEXTERN int ZEXPORT inflateBackInit OF((z_stream FAR *strm, int windowBits,
00737                                         unsigned char FAR *window));
00738 
00739      Initialize the internal stream state for decompression using inflateBack()
00740    calls.  The fields zalloc, zfree and opaque in strm must be initialized
00741    before the call.  If zalloc and zfree are Z_NULL, then the default library-
00742    derived memory allocation routines are used.  windowBits is the base two
00743    logarithm of the window size, in the range 8..15.  window is a caller
00744    supplied buffer of that size.  Except for special applications where it is
00745    assured that deflate was used with small window sizes, windowBits must be 15
00746    and a 32K byte window must be supplied to be able to decompress general
00747    deflate streams.
00748 
00749      See inflateBack() for the usage of these routines.
00750 
00751      inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
00752    the paramaters are invalid, Z_MEM_ERROR if the internal state could not
00753    be allocated, or Z_VERSION_ERROR if the version of the library does not
00754    match the version of the header file.
00755 */
00756 
00757 typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
00758 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
00759 
00760 ZEXTERN int ZEXPORT inflateBack OF((z_stream FAR *strm,
00761                                     in_func in, void FAR *in_desc,
00762                                     out_func out, void FAR *out_desc));
00763 /*
00764      inflateBack() does a raw inflate with a single call using a call-back
00765    interface for input and output.  This is more efficient than inflate() for
00766    file i/o applications in that it avoids copying between the output and the
00767    sliding window by simply making the window itself the output buffer.  This
00768    function trusts the application to not change the output buffer passed by
00769    the output function, at least until inflateBack() returns.
00770 
00771      inflateBackInit() must be called first to allocate the internal state
00772    and to initialize the state with the user-provided window buffer.
00773    inflateBack() may then be used multiple times to inflate a complete, raw
00774    deflate stream with each call.  inflateBackEnd() is then called to free
00775    the allocated state.
00776 
00777      A raw deflate stream is one with no zlib or gzip header or trailer.
00778    This routine would normally be used in a utility that reads zip or gzip
00779    files and writes out uncompressed files.  The utility would decode the
00780    header and process the trailer on its own, hence this routine expects
00781    only the raw deflate stream to decompress.  This is different from the
00782    normal behavior of inflate(), which expects either a zlib or gzip header and
00783    trailer around the deflate stream.
00784 
00785      inflateBack() uses two subroutines supplied by the caller that are then
00786    called by inflateBack() for input and output.  inflateBack() calls those
00787    routines until it reads a complete deflate stream and writes out all of the
00788    uncompressed data, or until it encounters an error.  The function's
00789    parameters and return types are defined above in the in_func and out_func
00790    typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
00791    number of bytes of provided input, and a pointer to that input in buf.  If
00792    there is no input available, in() must return zero--buf is ignored in that
00793    case--and inflateBack() will return a buffer error.  inflateBack() will call
00794    out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].  out()
00795    should return zero on success, or non-zero on failure.  If out() returns
00796    non-zero, inflateBack() will return with an error.  Neither in() nor out()
00797    are permitted to change the contents of the window provided to
00798    inflateBackInit(), which is also the buffer that out() uses to write from.
00799    The length written by out() will be at most the window size.  Any non-zero
00800    amount of input may be provided by in().
00801 
00802      For convenience, inflateBack() can be provided input on the first call by
00803    setting strm->next_in and strm->avail_in.  If that input is exhausted, then
00804    in() will be called.  Therefore strm->next_in must be initialized before
00805    calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
00806    immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
00807    must also be initialized, and then if strm->avail_in is not zero, input will
00808    initially be taken from strm->next_in[0 .. strm->avail_in - 1].
00809 
00810      The in_desc and out_desc parameters of inflateBack() is passed as the
00811    first parameter of in() and out() respectively when they are called.  These
00812    descriptors can be optionally used to pass any information that the caller-
00813    supplied in() and out() functions need to do their job.
00814 
00815      On return, inflateBack() will set strm->next_in and strm->avail_in to
00816    pass back any unused input that was provided by the last in() call.  The
00817    return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
00818    if in() or out() returned an error, Z_DATA_ERROR if there was a format
00819    error in the deflate stream (in which case strm->msg is set to indicate the
00820    nature of the error), or Z_STREAM_ERROR if the stream was not properly
00821    initialized.  In the case of Z_BUF_ERROR, an input or output error can be
00822    distinguished using strm->next_in which will be Z_NULL only if in() returned
00823    an error.  If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
00824    out() returning non-zero.  (in() will always be called before out(), so
00825    strm->next_in is assured to be defined if out() returns non-zero.)  Note
00826    that inflateBack() cannot return Z_OK.
00827 */
00828 
00829 ZEXTERN int ZEXPORT inflateBackEnd OF((z_stream FAR *strm));
00830 /*
00831      All memory allocated by inflateBackInit() is freed.
00832 
00833      inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
00834    state was inconsistent.
00835 */
00836 
00837 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
00838 /* Return flags indicating compile-time options.
00839 
00840     Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
00841      1.0: size of uInt
00842      3.2: size of uLong
00843      5.4: size of voidpf (pointer)
00844      7.6: size of z_off_t
00845 
00846     Compiler, assembler, and debug options:
00847      8: DEBUG
00848      9: ASMV or ASMINF -- use ASM code
00849      10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
00850      11: 0 (reserved)
00851 
00852     One-time table building (smaller code, but not thread-safe if true):
00853      12: BUILDFIXED -- build static block decoding tables when needed
00854      13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
00855      14,15: 0 (reserved)
00856 
00857     Library content (indicates missing functionality):
00858      16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
00859                           deflate code when not needed)
00860      17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
00861                     and decode gzip streams (to avoid linking crc code)
00862      18-19: 0 (reserved)
00863 
00864     Operation variations (changes in library functionality):
00865      20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
00866      21: FASTEST -- deflate algorithm with only one, lowest compression level
00867      22,23: 0 (reserved)
00868 
00869     The sprintf variant used by gzprintf (zero is best):
00870      24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
00871      25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
00872      26: 0 = returns value, 1 = void -- 1 means inferred string length returned
00873 
00874     Remainder:
00875      27-31: 0 (reserved)
00876  */
00877 
00878 
00879                         /* utility functions */
00880 
00881 /*
00882      The following utility functions are implemented on top of the
00883    basic stream-oriented functions. To simplify the interface, some
00884    default options are assumed (compression level and memory usage,
00885    standard memory allocation functions). The source code of these
00886    utility functions can easily be modified if you need special options.
00887 */
00888 
00889 ZEXTERN int Q_ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
00890                                  const Bytef *source, uLong sourceLen));
00891 /*
00892      Compresses the source buffer into the destination buffer.  sourceLen is
00893    the byte length of the source buffer. Upon entry, destLen is the total
00894    size of the destination buffer, which must be at least the value returned
00895    by compressBound(sourceLen). Upon exit, destLen is the actual size of the
00896    compressed buffer.
00897      This function can be used to compress a whole file at once if the
00898    input file is mmap'ed.
00899      compress returns Z_OK if success, Z_MEM_ERROR if there was not
00900    enough memory, Z_BUF_ERROR if there was not enough room in the output
00901    buffer.
00902 */
00903 
00904 ZEXTERN int Q_ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
00905                                   const Bytef *source, uLong sourceLen,
00906                                   int level));
00907 /*
00908      Compresses the source buffer into the destination buffer. The level
00909    parameter has the same meaning as in deflateInit.  sourceLen is the byte
00910    length of the source buffer. Upon entry, destLen is the total size of the
00911    destination buffer, which must be at least the value returned by
00912    compressBound(sourceLen). Upon exit, destLen is the actual size of the
00913    compressed buffer.
00914 
00915      compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
00916    memory, Z_BUF_ERROR if there was not enough room in the output buffer,
00917    Z_STREAM_ERROR if the level parameter is invalid.
00918 */
00919 
00920 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
00921 /*
00922      compressBound() returns an upper bound on the compressed size after
00923    compress() or compress2() on sourceLen bytes.  It would be used before
00924    a compress() or compress2() call to allocate the destination buffer.
00925 */
00926 
00927 ZEXTERN int Q_ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
00928                                    const Bytef *source, uLong sourceLen));
00929 /*
00930      Decompresses the source buffer into the destination buffer.  sourceLen is
00931    the byte length of the source buffer. Upon entry, destLen is the total
00932    size of the destination buffer, which must be large enough to hold the
00933    entire uncompressed data. (The size of the uncompressed data must have
00934    been saved previously by the compressor and transmitted to the decompressor
00935    by some mechanism outside the scope of this compression library.)
00936    Upon exit, destLen is the actual size of the compressed buffer.
00937      This function can be used to decompress a whole file at once if the
00938    input file is mmap'ed.
00939 
00940      uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
00941    enough memory, Z_BUF_ERROR if there was not enough room in the output
00942    buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
00943 */
00944 
00945 
00946 typedef voidp gzFile;
00947 
00948 ZEXTERN gzFile Q_ZEXPORT gzopen  OF((const char *path, const char *mode));
00949 /*
00950      Opens a gzip (.gz) file for reading or writing. The mode parameter
00951    is as in fopen ("rb" or "wb") but can also include a compression level
00952    ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
00953    Huffman only compression as in "wb1h", or 'R' for run-length encoding
00954    as in "wb1R". (See the description of deflateInit2 for more information
00955    about the strategy parameter.)
00956 
00957      gzopen can be used to read a file which is not in gzip format; in this
00958    case gzread will directly read from the file without decompression.
00959 
00960      gzopen returns NULL if the file could not be opened or if there was
00961    insufficient memory to allocate the (de)compression state; errno
00962    can be checked to distinguish the two cases (if errno is zero, the
00963    zlib error is Z_MEM_ERROR).  */
00964 
00965 ZEXTERN gzFile Q_ZEXPORT gzdopen  OF((int fd, const char *mode));
00966 /*
00967      gzdopen() associates a gzFile with the file descriptor fd.  File
00968    descriptors are obtained from calls like open, dup, creat, pipe or
00969    fileno (in the file has been previously opened with fopen).
00970    The mode parameter is as in gzopen.
00971      The next call of gzclose on the returned gzFile will also close the
00972    file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
00973    descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
00974      gzdopen returns NULL if there was insufficient memory to allocate
00975    the (de)compression state.
00976 */
00977 
00978 ZEXTERN int Q_ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
00979 /*
00980      Dynamically update the compression level or strategy. See the description
00981    of deflateInit2 for the meaning of these parameters.
00982      gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
00983    opened for writing.
00984 */
00985 
00986 ZEXTERN int Q_ZEXPORT    gzread  OF((gzFile file, voidp buf, unsigned len));
00987 /*
00988      Reads the given number of uncompressed bytes from the compressed file.
00989    If the input file was not in gzip format, gzread copies the given number
00990    of bytes into the buffer.
00991      gzread returns the number of uncompressed bytes actually read (0 for
00992    end of file, -1 for error). */
00993 
00994 ZEXTERN int Q_ZEXPORT    gzwrite OF((gzFile file,
00995                                    voidpc buf, unsigned len));
00996 /*
00997      Writes the given number of uncompressed bytes into the compressed file.
00998    gzwrite returns the number of uncompressed bytes actually written
00999    (0 in case of error).
01000 */
01001 
01002 ZEXTERN int ZEXPORTVA   gzprintf OF((gzFile file, const char *format, ...));
01003 /*
01004      Converts, formats, and writes the args to the compressed file under
01005    control of the format string, as in fprintf. gzprintf returns the number of
01006    uncompressed bytes actually written (0 in case of error).  The number of
01007    uncompressed bytes written is limited to 4095. The caller should assure that
01008    this limit is not exceeded. If it is exceeded, then gzprintf() will return
01009    return an error (0) with nothing written. In this case, there may also be a
01010    buffer overflow with unpredictable consequences, which is possible only if
01011    zlib was compiled with the insecure functions sprintf() or vsprintf()
01012    because the secure snprintf() or vsnprintf() functions were not available.
01013 */
01014 
01015 ZEXTERN int Q_ZEXPORT gzputs OF((gzFile file, const char *s));
01016 /*
01017       Writes the given null-terminated string to the compressed file, excluding
01018    the terminating null character.
01019       gzputs returns the number of characters written, or -1 in case of error.
01020 */
01021 
01022 ZEXTERN Q_ZEXPORT char * gzgets OF((gzFile file, char *buf, int len));
01023 /*
01024       Reads bytes from the compressed file until len-1 characters are read, or
01025    a newline character is read and transferred to buf, or an end-of-file
01026    condition is encountered.  The string is then terminated with a null
01027    character.
01028       gzgets returns buf, or Z_NULL in case of error.
01029 */
01030 
01031 ZEXTERN int Q_ZEXPORT    gzputc OF((gzFile file, int c));
01032 /*
01033       Writes c, converted to an unsigned char, into the compressed file.
01034    gzputc returns the value that was written, or -1 in case of error.
01035 */
01036 
01037 ZEXTERN int Q_ZEXPORT    gzgetc OF((gzFile file));
01038 /*
01039       Reads one byte from the compressed file. gzgetc returns this byte
01040    or -1 in case of end of file or error.
01041 */
01042 
01043 ZEXTERN int ZEXPORT    gzungetc OF((int c, gzFile file));
01044 /*
01045       Push one character back onto the stream to be read again later.
01046    Only one character of push-back is allowed.  gzungetc() returns the
01047    character pushed, or -1 on failure.  gzungetc() will fail if a
01048    character has been pushed but not read yet, or if c is -1. The pushed
01049    character will be discarded if the stream is repositioned with gzseek()
01050    or gzrewind().
01051 */
01052 
01053 ZEXTERN int Q_ZEXPORT    gzflush OF((gzFile file, int flush));
01054 /*
01055      Flushes all pending output into the compressed file. The parameter
01056    flush is as in the deflate() function. The return value is the zlib
01057    error number (see function gzerror below). gzflush returns Z_OK if
01058    the flush parameter is Z_FINISH and all output could be flushed.
01059      gzflush should be called only when strictly necessary because it can
01060    degrade compression.
01061 */
01062 
01063 ZEXTERN z_off_t Q_ZEXPORT    gzseek OF((gzFile file,
01064                                       z_off_t offset, int whence));
01065 /*
01066       Sets the starting position for the next gzread or gzwrite on the
01067    given compressed file. The offset represents a number of bytes in the
01068    uncompressed data stream. The whence parameter is defined as in lseek(2);
01069    the value SEEK_END is not supported.
01070      If the file is opened for reading, this function is emulated but can be
01071    extremely slow. If the file is opened for writing, only forward seeks are
01072    supported; gzseek then compresses a sequence of zeroes up to the new
01073    starting position.
01074 
01075       gzseek returns the resulting offset location as measured in bytes from
01076    the beginning of the uncompressed stream, or -1 in case of error, in
01077    particular if the file is opened for writing and the new starting position
01078    would be before the current position.
01079 */
01080 
01081 ZEXTERN int Q_ZEXPORT    gzrewind OF((gzFile file));
01082 /*
01083      Rewinds the given file. This function is supported only for reading.
01084 
01085    gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
01086 */
01087 
01088 ZEXTERN z_off_t Q_ZEXPORT    gztell OF((gzFile file));
01089 /*
01090      Returns the starting position for the next gzread or gzwrite on the
01091    given compressed file. This position represents a number of bytes in the
01092    uncompressed data stream.
01093 
01094    gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
01095 */
01096 
01097 ZEXTERN int Q_ZEXPORT gzeof OF((gzFile file));
01098 /*
01099      Returns 1 when EOF has previously been detected reading the given
01100    input stream, otherwise zero.
01101 */
01102 
01103 ZEXTERN int Q_ZEXPORT    gzclose OF((gzFile file));
01104 /*
01105      Flushes all pending output if necessary, closes the compressed file
01106    and deallocates all the (de)compression state. The return value is the zlib
01107    error number (see function gzerror below).
01108 */
01109 
01110 ZEXTERN Q_ZEXPORT const char * gzerror OF((gzFile file, int *errnum));
01111 /*
01112      Returns the error message for the last error which occurred on the
01113    given compressed file. errnum is set to zlib error number. If an
01114    error occurred in the file system and not in the compression library,
01115    errnum is set to Z_ERRNO and the application may consult errno
01116    to get the exact error code.
01117 */
01118 
01119 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
01120 /*
01121      Clears the error and end-of-file flags for file. This is analogous to the
01122    clearerr() function in stdio. This is useful for continuing to read a gzip
01123    file that is being written concurrently.
01124 */
01125 
01126                         /* checksum functions */
01127 
01128 /*
01129      These functions are not related to compression but are exported
01130    anyway because they might be useful in applications using the
01131    compression library.
01132 */
01133 
01134 ZEXTERN uLong Q_ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
01135 
01136 /*
01137      Update a running Adler-32 checksum with the bytes buf[0..len-1] and
01138    return the updated checksum. If buf is NULL, this function returns
01139    the required initial value for the checksum.
01140    An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
01141    much faster. Usage example:
01142 
01143      uLong adler = adler32(0L, Z_NULL, 0);
01144 
01145      while (read_buffer(buffer, length) != EOF) {
01146        adler = adler32(adler, buffer, length);
01147      }
01148      if (adler != original_adler) error();
01149 */
01150 
01151 ZEXTERN uLong Q_ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
01152 /*
01153      Update a running crc with the bytes buf[0..len-1] and return the updated
01154    crc. If buf is NULL, this function returns the required initial value
01155    for the crc. Pre- and post-conditioning (one's complement) is performed
01156    within this function so it shouldn't be done by the application.
01157    Usage example:
01158 
01159      uLong crc = crc32(0L, Z_NULL, 0);
01160 
01161      while (read_buffer(buffer, length) != EOF) {
01162        crc = crc32(crc, buffer, length);
01163      }
01164      if (crc != original_crc) error();
01165 */
01166 
01167 
01168                         /* various hacks, don't look :) */
01169 
01170 /* deflateInit and inflateInit are macros to allow checking the zlib version
01171  * and the compiler's view of z_stream:
01172  */
01173 ZEXTERN int Q_ZEXPORT deflateInit_ OF((z_streamp strm, int level,
01174                                      const char *version, int stream_size));
01175 ZEXTERN int Q_ZEXPORT inflateInit_ OF((z_streamp strm,
01176                                      const char *version, int stream_size));
01177 ZEXTERN int Q_ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
01178                                       int windowBits, int memLevel,
01179                                       int strategy, const char *version,
01180                                       int stream_size));
01181 ZEXTERN int Q_ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
01182                                       const char *version, int stream_size));
01183 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_stream FAR *strm, int windowBits,
01184                                          unsigned char FAR *window,
01185                                          const char *version,
01186                                          int stream_size));
01187 #define deflateInit(strm, level) \
01188         deflateInit_((strm), (level),       ZLIB_VERSION, sizeof(z_stream))
01189 #define inflateInit(strm) \
01190         inflateInit_((strm),                ZLIB_VERSION, sizeof(z_stream))
01191 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
01192         deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
01193                       (strategy),           ZLIB_VERSION, sizeof(z_stream))
01194 #define inflateInit2(strm, windowBits) \
01195         inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
01196 #define inflateBackInit(strm, windowBits, window) \
01197         inflateBackInit_((strm), (windowBits), (window), \
01198         ZLIB_VERSION, sizeof(z_stream))
01199 
01200 
01201 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
01202     struct internal_state {int dummy;}; /* hack for buggy compilers */
01203 #endif
01204 
01205 ZEXTERN Q_ZEXPORT const char   * zError           OF((int));
01206 ZEXTERN int            Q_ZEXPORT inflateSyncPoint OF((z_streamp z));
01207 ZEXTERN Q_ZEXPORT const uLongf * get_crc_table    OF((void));
01208 
01209 #ifdef __cplusplus
01210 }
01211 #endif
01212 
01213 #endif /* ZLIB_H */
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