xref: /plan9/sys/src/cmd/gs/zlib/zlib.h (revision 593dc095aefb2a85c828727bbfa9da139a49bdf4)
17dd7cddfSDavid du Colombier /* zlib.h -- interface of the 'zlib' general purpose compression library
2*593dc095SDavid du Colombier   version 1.2.2, October 3rd, 2004
37dd7cddfSDavid du Colombier 
4*593dc095SDavid du Colombier   Copyright (C) 1995-2004 Jean-loup Gailly and Mark Adler
57dd7cddfSDavid du Colombier 
67dd7cddfSDavid du Colombier   This software is provided 'as-is', without any express or implied
77dd7cddfSDavid du Colombier   warranty.  In no event will the authors be held liable for any damages
87dd7cddfSDavid du Colombier   arising from the use of this software.
97dd7cddfSDavid du Colombier 
107dd7cddfSDavid du Colombier   Permission is granted to anyone to use this software for any purpose,
117dd7cddfSDavid du Colombier   including commercial applications, and to alter it and redistribute it
127dd7cddfSDavid du Colombier   freely, subject to the following restrictions:
137dd7cddfSDavid du Colombier 
147dd7cddfSDavid du Colombier   1. The origin of this software must not be misrepresented; you must not
157dd7cddfSDavid du Colombier      claim that you wrote the original software. If you use this software
167dd7cddfSDavid du Colombier      in a product, an acknowledgment in the product documentation would be
177dd7cddfSDavid du Colombier      appreciated but is not required.
187dd7cddfSDavid du Colombier   2. Altered source versions must be plainly marked as such, and must not be
197dd7cddfSDavid du Colombier      misrepresented as being the original software.
207dd7cddfSDavid du Colombier   3. This notice may not be removed or altered from any source distribution.
217dd7cddfSDavid du Colombier 
227dd7cddfSDavid du Colombier   Jean-loup Gailly        Mark Adler
23*593dc095SDavid du Colombier   jloup@gzip.org          madler@alumni.caltech.edu
247dd7cddfSDavid du Colombier 
257dd7cddfSDavid du Colombier 
267dd7cddfSDavid du Colombier   The data format used by the zlib library is described by RFCs (Request for
27*593dc095SDavid du Colombier   Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
287dd7cddfSDavid du Colombier   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
297dd7cddfSDavid du Colombier */
307dd7cddfSDavid du Colombier 
31*593dc095SDavid du Colombier #ifndef ZLIB_H
32*593dc095SDavid du Colombier #define ZLIB_H
33*593dc095SDavid du Colombier 
34*593dc095SDavid du Colombier #include "zconf.h"
357dd7cddfSDavid du Colombier 
367dd7cddfSDavid du Colombier #ifdef __cplusplus
377dd7cddfSDavid du Colombier extern "C" {
387dd7cddfSDavid du Colombier #endif
397dd7cddfSDavid du Colombier 
40*593dc095SDavid du Colombier #define ZLIB_VERSION "1.2.2"
41*593dc095SDavid du Colombier #define ZLIB_VERNUM 0x1220
427dd7cddfSDavid du Colombier 
437dd7cddfSDavid du Colombier /*
447dd7cddfSDavid du Colombier      The 'zlib' compression library provides in-memory compression and
457dd7cddfSDavid du Colombier   decompression functions, including integrity checks of the uncompressed
467dd7cddfSDavid du Colombier   data.  This version of the library supports only one compression method
47*593dc095SDavid du Colombier   (deflation) but other algorithms will be added later and will have the same
487dd7cddfSDavid du Colombier   stream interface.
497dd7cddfSDavid du Colombier 
507dd7cddfSDavid du Colombier      Compression can be done in a single step if the buffers are large
517dd7cddfSDavid du Colombier   enough (for example if an input file is mmap'ed), or can be done by
527dd7cddfSDavid du Colombier   repeated calls of the compression function.  In the latter case, the
537dd7cddfSDavid du Colombier   application must provide more input and/or consume the output
547dd7cddfSDavid du Colombier   (providing more output space) before each call.
557dd7cddfSDavid du Colombier 
56*593dc095SDavid du Colombier      The compressed data format used by default by the in-memory functions is
57*593dc095SDavid du Colombier   the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
58*593dc095SDavid du Colombier   around a deflate stream, which is itself documented in RFC 1951.
59*593dc095SDavid du Colombier 
60*593dc095SDavid du Colombier      The library also supports reading and writing files in gzip (.gz) format
61*593dc095SDavid du Colombier   with an interface similar to that of stdio using the functions that start
62*593dc095SDavid du Colombier   with "gz".  The gzip format is different from the zlib format.  gzip is a
63*593dc095SDavid du Colombier   gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
64*593dc095SDavid du Colombier 
65*593dc095SDavid du Colombier      This library can optionally read and write gzip streams in memory as well.
66*593dc095SDavid du Colombier 
67*593dc095SDavid du Colombier      The zlib format was designed to be compact and fast for use in memory
68*593dc095SDavid du Colombier   and on communications channels.  The gzip format was designed for single-
69*593dc095SDavid du Colombier   file compression on file systems, has a larger header than zlib to maintain
70*593dc095SDavid du Colombier   directory information, and uses a different, slower check method than zlib.
71*593dc095SDavid du Colombier 
72*593dc095SDavid du Colombier      The library does not install any signal handler. The decoder checks
73*593dc095SDavid du Colombier   the consistency of the compressed data, so the library should never
74*593dc095SDavid du Colombier   crash even in case of corrupted input.
757dd7cddfSDavid du Colombier */
767dd7cddfSDavid du Colombier 
777dd7cddfSDavid du Colombier typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
787dd7cddfSDavid du Colombier typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
797dd7cddfSDavid du Colombier 
807dd7cddfSDavid du Colombier struct internal_state;
817dd7cddfSDavid du Colombier 
827dd7cddfSDavid du Colombier typedef struct z_stream_s {
837dd7cddfSDavid du Colombier     Bytef    *next_in;  /* next input byte */
847dd7cddfSDavid du Colombier     uInt     avail_in;  /* number of bytes available at next_in */
857dd7cddfSDavid du Colombier     uLong    total_in;  /* total nb of input bytes read so far */
867dd7cddfSDavid du Colombier 
877dd7cddfSDavid du Colombier     Bytef    *next_out; /* next output byte should be put there */
887dd7cddfSDavid du Colombier     uInt     avail_out; /* remaining free space at next_out */
897dd7cddfSDavid du Colombier     uLong    total_out; /* total nb of bytes output so far */
907dd7cddfSDavid du Colombier 
917dd7cddfSDavid du Colombier     char     *msg;      /* last error message, NULL if no error */
927dd7cddfSDavid du Colombier     struct internal_state FAR *state; /* not visible by applications */
937dd7cddfSDavid du Colombier 
947dd7cddfSDavid du Colombier     alloc_func zalloc;  /* used to allocate the internal state */
957dd7cddfSDavid du Colombier     free_func  zfree;   /* used to free the internal state */
967dd7cddfSDavid du Colombier     voidpf     opaque;  /* private data object passed to zalloc and zfree */
977dd7cddfSDavid du Colombier 
987dd7cddfSDavid du Colombier     int     data_type;  /* best guess about the data type: ascii or binary */
997dd7cddfSDavid du Colombier     uLong   adler;      /* adler32 value of the uncompressed data */
1007dd7cddfSDavid du Colombier     uLong   reserved;   /* reserved for future use */
1017dd7cddfSDavid du Colombier } z_stream;
1027dd7cddfSDavid du Colombier 
1037dd7cddfSDavid du Colombier typedef z_stream FAR *z_streamp;
1047dd7cddfSDavid du Colombier 
1057dd7cddfSDavid du Colombier /*
1067dd7cddfSDavid du Colombier    The application must update next_in and avail_in when avail_in has
1077dd7cddfSDavid du Colombier    dropped to zero. It must update next_out and avail_out when avail_out
1087dd7cddfSDavid du Colombier    has dropped to zero. The application must initialize zalloc, zfree and
1097dd7cddfSDavid du Colombier    opaque before calling the init function. All other fields are set by the
1107dd7cddfSDavid du Colombier    compression library and must not be updated by the application.
1117dd7cddfSDavid du Colombier 
1127dd7cddfSDavid du Colombier    The opaque value provided by the application will be passed as the first
1137dd7cddfSDavid du Colombier    parameter for calls of zalloc and zfree. This can be useful for custom
1147dd7cddfSDavid du Colombier    memory management. The compression library attaches no meaning to the
1157dd7cddfSDavid du Colombier    opaque value.
1167dd7cddfSDavid du Colombier 
1177dd7cddfSDavid du Colombier    zalloc must return Z_NULL if there is not enough memory for the object.
118*593dc095SDavid du Colombier    If zlib is used in a multi-threaded application, zalloc and zfree must be
119*593dc095SDavid du Colombier    thread safe.
120*593dc095SDavid du Colombier 
1217dd7cddfSDavid du Colombier    On 16-bit systems, the functions zalloc and zfree must be able to allocate
1227dd7cddfSDavid du Colombier    exactly 65536 bytes, but will not be required to allocate more than this
1237dd7cddfSDavid du Colombier    if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
1247dd7cddfSDavid du Colombier    pointers returned by zalloc for objects of exactly 65536 bytes *must*
1257dd7cddfSDavid du Colombier    have their offset normalized to zero. The default allocation function
1267dd7cddfSDavid du Colombier    provided by this library ensures this (see zutil.c). To reduce memory
1277dd7cddfSDavid du Colombier    requirements and avoid any allocation of 64K objects, at the expense of
1287dd7cddfSDavid du Colombier    compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
1297dd7cddfSDavid du Colombier 
1307dd7cddfSDavid du Colombier    The fields total_in and total_out can be used for statistics or
1317dd7cddfSDavid du Colombier    progress reports. After compression, total_in holds the total size of
1327dd7cddfSDavid du Colombier    the uncompressed data and may be saved for use in the decompressor
1337dd7cddfSDavid du Colombier    (particularly if the decompressor wants to decompress everything in
1347dd7cddfSDavid du Colombier    a single step).
1357dd7cddfSDavid du Colombier */
1367dd7cddfSDavid du Colombier 
1377dd7cddfSDavid du Colombier                         /* constants */
1387dd7cddfSDavid du Colombier 
1397dd7cddfSDavid du Colombier #define Z_NO_FLUSH      0
140*593dc095SDavid du Colombier #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
1417dd7cddfSDavid du Colombier #define Z_SYNC_FLUSH    2
1427dd7cddfSDavid du Colombier #define Z_FULL_FLUSH    3
1437dd7cddfSDavid du Colombier #define Z_FINISH        4
144*593dc095SDavid du Colombier #define Z_BLOCK         5
145*593dc095SDavid du Colombier /* Allowed flush values; see deflate() and inflate() below for details */
1467dd7cddfSDavid du Colombier 
1477dd7cddfSDavid du Colombier #define Z_OK            0
1487dd7cddfSDavid du Colombier #define Z_STREAM_END    1
1497dd7cddfSDavid du Colombier #define Z_NEED_DICT     2
1507dd7cddfSDavid du Colombier #define Z_ERRNO        (-1)
1517dd7cddfSDavid du Colombier #define Z_STREAM_ERROR (-2)
1527dd7cddfSDavid du Colombier #define Z_DATA_ERROR   (-3)
1537dd7cddfSDavid du Colombier #define Z_MEM_ERROR    (-4)
1547dd7cddfSDavid du Colombier #define Z_BUF_ERROR    (-5)
1557dd7cddfSDavid du Colombier #define Z_VERSION_ERROR (-6)
1567dd7cddfSDavid du Colombier /* Return codes for the compression/decompression functions. Negative
1577dd7cddfSDavid du Colombier  * values are errors, positive values are used for special but normal events.
1587dd7cddfSDavid du Colombier  */
1597dd7cddfSDavid du Colombier 
1607dd7cddfSDavid du Colombier #define Z_NO_COMPRESSION         0
1617dd7cddfSDavid du Colombier #define Z_BEST_SPEED             1
1627dd7cddfSDavid du Colombier #define Z_BEST_COMPRESSION       9
1637dd7cddfSDavid du Colombier #define Z_DEFAULT_COMPRESSION  (-1)
1647dd7cddfSDavid du Colombier /* compression levels */
1657dd7cddfSDavid du Colombier 
1667dd7cddfSDavid du Colombier #define Z_FILTERED            1
1677dd7cddfSDavid du Colombier #define Z_HUFFMAN_ONLY        2
168*593dc095SDavid du Colombier #define Z_RLE                 3
1697dd7cddfSDavid du Colombier #define Z_DEFAULT_STRATEGY    0
1707dd7cddfSDavid du Colombier /* compression strategy; see deflateInit2() below for details */
1717dd7cddfSDavid du Colombier 
1727dd7cddfSDavid du Colombier #define Z_BINARY   0
1737dd7cddfSDavid du Colombier #define Z_ASCII    1
1747dd7cddfSDavid du Colombier #define Z_UNKNOWN  2
175*593dc095SDavid du Colombier /* Possible values of the data_type field (though see inflate()) */
1767dd7cddfSDavid du Colombier 
1777dd7cddfSDavid du Colombier #define Z_DEFLATED   8
1787dd7cddfSDavid du Colombier /* The deflate compression method (the only one supported in this version) */
1797dd7cddfSDavid du Colombier 
1807dd7cddfSDavid du Colombier #define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
1817dd7cddfSDavid du Colombier 
1827dd7cddfSDavid du Colombier #define zlib_version zlibVersion()
1837dd7cddfSDavid du Colombier /* for compatibility with versions < 1.0.2 */
1847dd7cddfSDavid du Colombier 
1857dd7cddfSDavid du Colombier                         /* basic functions */
1867dd7cddfSDavid du Colombier 
187*593dc095SDavid du Colombier ZEXTERN const char * ZEXPORT zlibVersion OF((void));
1887dd7cddfSDavid du Colombier /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
1897dd7cddfSDavid du Colombier    If the first character differs, the library code actually used is
1907dd7cddfSDavid du Colombier    not compatible with the zlib.h header file used by the application.
1917dd7cddfSDavid du Colombier    This check is automatically made by deflateInit and inflateInit.
1927dd7cddfSDavid du Colombier  */
1937dd7cddfSDavid du Colombier 
1947dd7cddfSDavid du Colombier /*
195*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
1967dd7cddfSDavid du Colombier 
1977dd7cddfSDavid du Colombier      Initializes the internal stream state for compression. The fields
1987dd7cddfSDavid du Colombier    zalloc, zfree and opaque must be initialized before by the caller.
1997dd7cddfSDavid du Colombier    If zalloc and zfree are set to Z_NULL, deflateInit updates them to
2007dd7cddfSDavid du Colombier    use default allocation functions.
2017dd7cddfSDavid du Colombier 
2027dd7cddfSDavid du Colombier      The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
2037dd7cddfSDavid du Colombier    1 gives best speed, 9 gives best compression, 0 gives no compression at
2047dd7cddfSDavid du Colombier    all (the input data is simply copied a block at a time).
2057dd7cddfSDavid du Colombier    Z_DEFAULT_COMPRESSION requests a default compromise between speed and
2067dd7cddfSDavid du Colombier    compression (currently equivalent to level 6).
2077dd7cddfSDavid du Colombier 
2087dd7cddfSDavid du Colombier      deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
2097dd7cddfSDavid du Colombier    enough memory, Z_STREAM_ERROR if level is not a valid compression level,
2107dd7cddfSDavid du Colombier    Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
2117dd7cddfSDavid du Colombier    with the version assumed by the caller (ZLIB_VERSION).
2127dd7cddfSDavid du Colombier    msg is set to null if there is no error message.  deflateInit does not
2137dd7cddfSDavid du Colombier    perform any compression: this will be done by deflate().
2147dd7cddfSDavid du Colombier */
2157dd7cddfSDavid du Colombier 
2167dd7cddfSDavid du Colombier 
217*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
2187dd7cddfSDavid du Colombier /*
219*593dc095SDavid du Colombier     deflate compresses as much data as possible, and stops when the input
220*593dc095SDavid du Colombier   buffer becomes empty or the output buffer becomes full. It may introduce some
221*593dc095SDavid du Colombier   output latency (reading input without producing any output) except when
222*593dc095SDavid du Colombier   forced to flush.
223*593dc095SDavid du Colombier 
224*593dc095SDavid du Colombier     The detailed semantics are as follows. deflate performs one or both of the
225*593dc095SDavid du Colombier   following actions:
2267dd7cddfSDavid du Colombier 
2277dd7cddfSDavid du Colombier   - Compress more input starting at next_in and update next_in and avail_in
2287dd7cddfSDavid du Colombier     accordingly. If not all input can be processed (because there is not
2297dd7cddfSDavid du Colombier     enough room in the output buffer), next_in and avail_in are updated and
2307dd7cddfSDavid du Colombier     processing will resume at this point for the next call of deflate().
2317dd7cddfSDavid du Colombier 
2327dd7cddfSDavid du Colombier   - Provide more output starting at next_out and update next_out and avail_out
2337dd7cddfSDavid du Colombier     accordingly. This action is forced if the parameter flush is non zero.
2347dd7cddfSDavid du Colombier     Forcing flush frequently degrades the compression ratio, so this parameter
2357dd7cddfSDavid du Colombier     should be set only when necessary (in interactive applications).
2367dd7cddfSDavid du Colombier     Some output may be provided even if flush is not set.
2377dd7cddfSDavid du Colombier 
2387dd7cddfSDavid du Colombier   Before the call of deflate(), the application should ensure that at least
2397dd7cddfSDavid du Colombier   one of the actions is possible, by providing more input and/or consuming
2407dd7cddfSDavid du Colombier   more output, and updating avail_in or avail_out accordingly; avail_out
2417dd7cddfSDavid du Colombier   should never be zero before the call. The application can consume the
2427dd7cddfSDavid du Colombier   compressed output when it wants, for example when the output buffer is full
2437dd7cddfSDavid du Colombier   (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
2447dd7cddfSDavid du Colombier   and with zero avail_out, it must be called again after making room in the
2457dd7cddfSDavid du Colombier   output buffer because there might be more output pending.
2467dd7cddfSDavid du Colombier 
247*593dc095SDavid du Colombier     If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
248*593dc095SDavid du Colombier   flushed to the output buffer and the output is aligned on a byte boundary, so
249*593dc095SDavid du Colombier   that the decompressor can get all input data available so far. (In particular
250*593dc095SDavid du Colombier   avail_in is zero after the call if enough output space has been provided
251*593dc095SDavid du Colombier   before the call.)  Flushing may degrade compression for some compression
252*593dc095SDavid du Colombier   algorithms and so it should be used only when necessary.
253*593dc095SDavid du Colombier 
254*593dc095SDavid du Colombier     If flush is set to Z_FULL_FLUSH, all output is flushed as with
255*593dc095SDavid du Colombier   Z_SYNC_FLUSH, and the compression state is reset so that decompression can
256*593dc095SDavid du Colombier   restart from this point if previous compressed data has been damaged or if
257*593dc095SDavid du Colombier   random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
258*593dc095SDavid du Colombier   the compression.
259*593dc095SDavid du Colombier 
260*593dc095SDavid du Colombier     If deflate returns with avail_out == 0, this function must be called again
261*593dc095SDavid du Colombier   with the same value of the flush parameter and more output space (updated
262*593dc095SDavid du Colombier   avail_out), until the flush is complete (deflate returns with non-zero
263*593dc095SDavid du Colombier   avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
264*593dc095SDavid du Colombier   avail_out is greater than six to avoid repeated flush markers due to
265*593dc095SDavid du Colombier   avail_out == 0 on return.
2667dd7cddfSDavid du Colombier 
2677dd7cddfSDavid du Colombier     If the parameter flush is set to Z_FINISH, pending input is processed,
2687dd7cddfSDavid du Colombier   pending output is flushed and deflate returns with Z_STREAM_END if there
2697dd7cddfSDavid du Colombier   was enough output space; if deflate returns with Z_OK, this function must be
2707dd7cddfSDavid du Colombier   called again with Z_FINISH and more output space (updated avail_out) but no
2717dd7cddfSDavid du Colombier   more input data, until it returns with Z_STREAM_END or an error. After
2727dd7cddfSDavid du Colombier   deflate has returned Z_STREAM_END, the only possible operations on the
2737dd7cddfSDavid du Colombier   stream are deflateReset or deflateEnd.
2747dd7cddfSDavid du Colombier 
2757dd7cddfSDavid du Colombier     Z_FINISH can be used immediately after deflateInit if all the compression
2767dd7cddfSDavid du Colombier   is to be done in a single step. In this case, avail_out must be at least
277*593dc095SDavid du Colombier   the value returned by deflateBound (see below). If deflate does not return
2787dd7cddfSDavid du Colombier   Z_STREAM_END, then it must be called again as described above.
2797dd7cddfSDavid du Colombier 
280*593dc095SDavid du Colombier     deflate() sets strm->adler to the adler32 checksum of all input read
281*593dc095SDavid du Colombier   so far (that is, total_in bytes).
282*593dc095SDavid du Colombier 
2837dd7cddfSDavid du Colombier     deflate() may update data_type if it can make a good guess about
2847dd7cddfSDavid du Colombier   the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
2857dd7cddfSDavid du Colombier   binary. This field is only for information purposes and does not affect
2867dd7cddfSDavid du Colombier   the compression algorithm in any manner.
2877dd7cddfSDavid du Colombier 
2887dd7cddfSDavid du Colombier     deflate() returns Z_OK if some progress has been made (more input
2897dd7cddfSDavid du Colombier   processed or more output produced), Z_STREAM_END if all input has been
2907dd7cddfSDavid du Colombier   consumed and all output has been produced (only when flush is set to
2917dd7cddfSDavid du Colombier   Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
292*593dc095SDavid du Colombier   if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
293*593dc095SDavid du Colombier   (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
294*593dc095SDavid du Colombier   fatal, and deflate() can be called again with more input and more output
295*593dc095SDavid du Colombier   space to continue compressing.
2967dd7cddfSDavid du Colombier */
2977dd7cddfSDavid du Colombier 
2987dd7cddfSDavid du Colombier 
299*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
3007dd7cddfSDavid du Colombier /*
3017dd7cddfSDavid du Colombier      All dynamically allocated data structures for this stream are freed.
3027dd7cddfSDavid du Colombier    This function discards any unprocessed input and does not flush any
3037dd7cddfSDavid du Colombier    pending output.
3047dd7cddfSDavid du Colombier 
3057dd7cddfSDavid du Colombier      deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
3067dd7cddfSDavid du Colombier    stream state was inconsistent, Z_DATA_ERROR if the stream was freed
3077dd7cddfSDavid du Colombier    prematurely (some input or output was discarded). In the error case,
3087dd7cddfSDavid du Colombier    msg may be set but then points to a static string (which must not be
3097dd7cddfSDavid du Colombier    deallocated).
3107dd7cddfSDavid du Colombier */
3117dd7cddfSDavid du Colombier 
3127dd7cddfSDavid du Colombier 
3137dd7cddfSDavid du Colombier /*
314*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
3157dd7cddfSDavid du Colombier 
3167dd7cddfSDavid du Colombier      Initializes the internal stream state for decompression. The fields
317*593dc095SDavid du Colombier    next_in, avail_in, zalloc, zfree and opaque must be initialized before by
318*593dc095SDavid du Colombier    the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
319*593dc095SDavid du Colombier    value depends on the compression method), inflateInit determines the
320*593dc095SDavid du Colombier    compression method from the zlib header and allocates all data structures
321*593dc095SDavid du Colombier    accordingly; otherwise the allocation will be deferred to the first call of
322*593dc095SDavid du Colombier    inflate.  If zalloc and zfree are set to Z_NULL, inflateInit updates them to
323*593dc095SDavid du Colombier    use default allocation functions.
3247dd7cddfSDavid du Colombier 
325*593dc095SDavid du Colombier      inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
326*593dc095SDavid du Colombier    memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
327*593dc095SDavid du Colombier    version assumed by the caller.  msg is set to null if there is no error
328*593dc095SDavid du Colombier    message. inflateInit does not perform any decompression apart from reading
329*593dc095SDavid du Colombier    the zlib header if present: this will be done by inflate().  (So next_in and
330*593dc095SDavid du Colombier    avail_in may be modified, but next_out and avail_out are unchanged.)
3317dd7cddfSDavid du Colombier */
3327dd7cddfSDavid du Colombier 
3337dd7cddfSDavid du Colombier 
334*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
3357dd7cddfSDavid du Colombier /*
336*593dc095SDavid du Colombier     inflate decompresses as much data as possible, and stops when the input
337*593dc095SDavid du Colombier   buffer becomes empty or the output buffer becomes full. It may introduce
338*593dc095SDavid du Colombier   some output latency (reading input without producing any output) except when
339*593dc095SDavid du Colombier   forced to flush.
340*593dc095SDavid du Colombier 
341*593dc095SDavid du Colombier   The detailed semantics are as follows. inflate performs one or both of the
342*593dc095SDavid du Colombier   following actions:
3437dd7cddfSDavid du Colombier 
3447dd7cddfSDavid du Colombier   - Decompress more input starting at next_in and update next_in and avail_in
3457dd7cddfSDavid du Colombier     accordingly. If not all input can be processed (because there is not
3467dd7cddfSDavid du Colombier     enough room in the output buffer), next_in is updated and processing
3477dd7cddfSDavid du Colombier     will resume at this point for the next call of inflate().
3487dd7cddfSDavid du Colombier 
3497dd7cddfSDavid du Colombier   - Provide more output starting at next_out and update next_out and avail_out
3507dd7cddfSDavid du Colombier     accordingly.  inflate() provides as much output as possible, until there
3517dd7cddfSDavid du Colombier     is no more input data or no more space in the output buffer (see below
3527dd7cddfSDavid du Colombier     about the flush parameter).
3537dd7cddfSDavid du Colombier 
3547dd7cddfSDavid du Colombier   Before the call of inflate(), the application should ensure that at least
3557dd7cddfSDavid du Colombier   one of the actions is possible, by providing more input and/or consuming
3567dd7cddfSDavid du Colombier   more output, and updating the next_* and avail_* values accordingly.
3577dd7cddfSDavid du Colombier   The application can consume the uncompressed output when it wants, for
3587dd7cddfSDavid du Colombier   example when the output buffer is full (avail_out == 0), or after each
3597dd7cddfSDavid du Colombier   call of inflate(). If inflate returns Z_OK and with zero avail_out, it
3607dd7cddfSDavid du Colombier   must be called again after making room in the output buffer because there
3617dd7cddfSDavid du Colombier   might be more output pending.
3627dd7cddfSDavid du Colombier 
363*593dc095SDavid du Colombier     The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
364*593dc095SDavid du Colombier   Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
365*593dc095SDavid du Colombier   output as possible to the output buffer. Z_BLOCK requests that inflate() stop
366*593dc095SDavid du Colombier   if and when it get to the next deflate block boundary. When decoding the zlib
367*593dc095SDavid du Colombier   or gzip format, this will cause inflate() to return immediately after the
368*593dc095SDavid du Colombier   header and before the first block. When doing a raw inflate, inflate() will
369*593dc095SDavid du Colombier   go ahead and process the first block, and will return when it gets to the end
370*593dc095SDavid du Colombier   of that block, or when it runs out of data.
371*593dc095SDavid du Colombier 
372*593dc095SDavid du Colombier     The Z_BLOCK option assists in appending to or combining deflate streams.
373*593dc095SDavid du Colombier   Also to assist in this, on return inflate() will set strm->data_type to the
374*593dc095SDavid du Colombier   number of unused bits in the last byte taken from strm->next_in, plus 64
375*593dc095SDavid du Colombier   if inflate() is currently decoding the last block in the deflate stream,
376*593dc095SDavid du Colombier   plus 128 if inflate() returned immediately after decoding an end-of-block
377*593dc095SDavid du Colombier   code or decoding the complete header up to just before the first byte of the
378*593dc095SDavid du Colombier   deflate stream. The end-of-block will not be indicated until all of the
379*593dc095SDavid du Colombier   uncompressed data from that block has been written to strm->next_out.  The
380*593dc095SDavid du Colombier   number of unused bits may in general be greater than seven, except when
381*593dc095SDavid du Colombier   bit 7 of data_type is set, in which case the number of unused bits will be
382*593dc095SDavid du Colombier   less than eight.
3837dd7cddfSDavid du Colombier 
3847dd7cddfSDavid du Colombier     inflate() should normally be called until it returns Z_STREAM_END or an
3857dd7cddfSDavid du Colombier   error. However if all decompression is to be performed in a single step
3867dd7cddfSDavid du Colombier   (a single call of inflate), the parameter flush should be set to
3877dd7cddfSDavid du Colombier   Z_FINISH. In this case all pending input is processed and all pending
3887dd7cddfSDavid du Colombier   output is flushed; avail_out must be large enough to hold all the
3897dd7cddfSDavid du Colombier   uncompressed data. (The size of the uncompressed data may have been saved
3907dd7cddfSDavid du Colombier   by the compressor for this purpose.) The next operation on this stream must
3917dd7cddfSDavid du Colombier   be inflateEnd to deallocate the decompression state. The use of Z_FINISH
392*593dc095SDavid du Colombier   is never required, but can be used to inform inflate that a faster approach
3937dd7cddfSDavid du Colombier   may be used for the single inflate() call.
3947dd7cddfSDavid du Colombier 
395*593dc095SDavid du Colombier      In this implementation, inflate() always flushes as much output as
396*593dc095SDavid du Colombier   possible to the output buffer, and always uses the faster approach on the
397*593dc095SDavid du Colombier   first call. So the only effect of the flush parameter in this implementation
398*593dc095SDavid du Colombier   is on the return value of inflate(), as noted below, or when it returns early
399*593dc095SDavid du Colombier   because Z_BLOCK is used.
400*593dc095SDavid du Colombier 
401*593dc095SDavid du Colombier      If a preset dictionary is needed after this call (see inflateSetDictionary
402*593dc095SDavid du Colombier   below), inflate sets strm->adler to the adler32 checksum of the dictionary
403*593dc095SDavid du Colombier   chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
404*593dc095SDavid du Colombier   strm->adler to the adler32 checksum of all output produced so far (that is,
405*593dc095SDavid du Colombier   total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
406*593dc095SDavid du Colombier   below. At the end of the stream, inflate() checks that its computed adler32
407*593dc095SDavid du Colombier   checksum is equal to that saved by the compressor and returns Z_STREAM_END
408*593dc095SDavid du Colombier   only if the checksum is correct.
409*593dc095SDavid du Colombier 
410*593dc095SDavid du Colombier     inflate() will decompress and check either zlib-wrapped or gzip-wrapped
411*593dc095SDavid du Colombier   deflate data.  The header type is detected automatically.  Any information
412*593dc095SDavid du Colombier   contained in the gzip header is not retained, so applications that need that
413*593dc095SDavid du Colombier   information should instead use raw inflate, see inflateInit2() below, or
414*593dc095SDavid du Colombier   inflateBack() and perform their own processing of the gzip header and
415*593dc095SDavid du Colombier   trailer.
416*593dc095SDavid du Colombier 
417*593dc095SDavid du Colombier     inflate() returns Z_OK if some progress has been made (more input processed
418*593dc095SDavid du Colombier   or more output produced), Z_STREAM_END if the end of the compressed data has
419*593dc095SDavid du Colombier   been reached and all uncompressed output has been produced, Z_NEED_DICT if a
420*593dc095SDavid du Colombier   preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
421*593dc095SDavid du Colombier   corrupted (input stream not conforming to the zlib format or incorrect check
422*593dc095SDavid du Colombier   value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
423*593dc095SDavid du Colombier   if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
424*593dc095SDavid du Colombier   Z_BUF_ERROR if no progress is possible or if there was not enough room in the
425*593dc095SDavid du Colombier   output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
426*593dc095SDavid du Colombier   inflate() can be called again with more input and more output space to
427*593dc095SDavid du Colombier   continue decompressing. If Z_DATA_ERROR is returned, the application may then
428*593dc095SDavid du Colombier   call inflateSync() to look for a good compression block if a partial recovery
429*593dc095SDavid du Colombier   of the data is desired.
4307dd7cddfSDavid du Colombier */
4317dd7cddfSDavid du Colombier 
4327dd7cddfSDavid du Colombier 
433*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
4347dd7cddfSDavid du Colombier /*
4357dd7cddfSDavid du Colombier      All dynamically allocated data structures for this stream are freed.
4367dd7cddfSDavid du Colombier    This function discards any unprocessed input and does not flush any
4377dd7cddfSDavid du Colombier    pending output.
4387dd7cddfSDavid du Colombier 
4397dd7cddfSDavid du Colombier      inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
4407dd7cddfSDavid du Colombier    was inconsistent. In the error case, msg may be set but then points to a
4417dd7cddfSDavid du Colombier    static string (which must not be deallocated).
4427dd7cddfSDavid du Colombier */
4437dd7cddfSDavid du Colombier 
4447dd7cddfSDavid du Colombier                         /* Advanced functions */
4457dd7cddfSDavid du Colombier 
4467dd7cddfSDavid du Colombier /*
4477dd7cddfSDavid du Colombier     The following functions are needed only in some special applications.
4487dd7cddfSDavid du Colombier */
4497dd7cddfSDavid du Colombier 
4507dd7cddfSDavid du Colombier /*
451*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
4527dd7cddfSDavid du Colombier                                      int  level,
4537dd7cddfSDavid du Colombier                                      int  method,
4547dd7cddfSDavid du Colombier                                      int  windowBits,
4557dd7cddfSDavid du Colombier                                      int  memLevel,
4567dd7cddfSDavid du Colombier                                      int  strategy));
4577dd7cddfSDavid du Colombier 
4587dd7cddfSDavid du Colombier      This is another version of deflateInit with more compression options. The
4597dd7cddfSDavid du Colombier    fields next_in, zalloc, zfree and opaque must be initialized before by
4607dd7cddfSDavid du Colombier    the caller.
4617dd7cddfSDavid du Colombier 
4627dd7cddfSDavid du Colombier      The method parameter is the compression method. It must be Z_DEFLATED in
463*593dc095SDavid du Colombier    this version of the library.
4647dd7cddfSDavid du Colombier 
4657dd7cddfSDavid du Colombier      The windowBits parameter is the base two logarithm of the window size
4667dd7cddfSDavid du Colombier    (the size of the history buffer). It should be in the range 8..15 for this
467*593dc095SDavid du Colombier    version of the library. Larger values of this parameter result in better
468*593dc095SDavid du Colombier    compression at the expense of memory usage. The default value is 15 if
469*593dc095SDavid du Colombier    deflateInit is used instead.
470*593dc095SDavid du Colombier 
471*593dc095SDavid du Colombier      windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
472*593dc095SDavid du Colombier    determines the window size. deflate() will then generate raw deflate data
473*593dc095SDavid du Colombier    with no zlib header or trailer, and will not compute an adler32 check value.
474*593dc095SDavid du Colombier 
475*593dc095SDavid du Colombier      windowBits can also be greater than 15 for optional gzip encoding. Add
476*593dc095SDavid du Colombier    16 to windowBits to write a simple gzip header and trailer around the
477*593dc095SDavid du Colombier    compressed data instead of a zlib wrapper. The gzip header will have no
478*593dc095SDavid du Colombier    file name, no extra data, no comment, no modification time (set to zero),
479*593dc095SDavid du Colombier    no header crc, and the operating system will be set to 255 (unknown).  If a
480*593dc095SDavid du Colombier    gzip stream is being written, strm->adler is a crc32 instead of an adler32.
4817dd7cddfSDavid du Colombier 
4827dd7cddfSDavid du Colombier      The memLevel parameter specifies how much memory should be allocated
4837dd7cddfSDavid du Colombier    for the internal compression state. memLevel=1 uses minimum memory but
4847dd7cddfSDavid du Colombier    is slow and reduces compression ratio; memLevel=9 uses maximum memory
4857dd7cddfSDavid du Colombier    for optimal speed. The default value is 8. See zconf.h for total memory
4867dd7cddfSDavid du Colombier    usage as a function of windowBits and memLevel.
4877dd7cddfSDavid du Colombier 
4887dd7cddfSDavid du Colombier      The strategy parameter is used to tune the compression algorithm. Use the
4897dd7cddfSDavid du Colombier    value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
490*593dc095SDavid du Colombier    filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
491*593dc095SDavid du Colombier    string match), or Z_RLE to limit match distances to one (run-length
492*593dc095SDavid du Colombier    encoding). Filtered data consists mostly of small values with a somewhat
493*593dc095SDavid du Colombier    random distribution. In this case, the compression algorithm is tuned to
494*593dc095SDavid du Colombier    compress them better. The effect of Z_FILTERED is to force more Huffman
495*593dc095SDavid du Colombier    coding and less string matching; it is somewhat intermediate between
496*593dc095SDavid du Colombier    Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
497*593dc095SDavid du Colombier    Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
498*593dc095SDavid du Colombier    parameter only affects the compression ratio but not the correctness of the
499*593dc095SDavid du Colombier    compressed output even if it is not set appropriately.
5007dd7cddfSDavid du Colombier 
501*593dc095SDavid du Colombier       deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
502*593dc095SDavid du Colombier    memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
503*593dc095SDavid du Colombier    method). msg is set to null if there is no error message.  deflateInit2 does
504*593dc095SDavid du Colombier    not perform any compression: this will be done by deflate().
5057dd7cddfSDavid du Colombier */
5067dd7cddfSDavid du Colombier 
507*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
5087dd7cddfSDavid du Colombier                                              const Bytef *dictionary,
5097dd7cddfSDavid du Colombier                                              uInt  dictLength));
5107dd7cddfSDavid du Colombier /*
511*593dc095SDavid du Colombier      Initializes the compression dictionary from the given byte sequence
512*593dc095SDavid du Colombier    without producing any compressed output. This function must be called
513*593dc095SDavid du Colombier    immediately after deflateInit, deflateInit2 or deflateReset, before any
514*593dc095SDavid du Colombier    call of deflate. The compressor and decompressor must use exactly the same
5157dd7cddfSDavid du Colombier    dictionary (see inflateSetDictionary).
516*593dc095SDavid du Colombier 
5177dd7cddfSDavid du Colombier      The dictionary should consist of strings (byte sequences) that are likely
5187dd7cddfSDavid du Colombier    to be encountered later in the data to be compressed, with the most commonly
5197dd7cddfSDavid du Colombier    used strings preferably put towards the end of the dictionary. Using a
520*593dc095SDavid du Colombier    dictionary is most useful when the data to be compressed is short and can be
521*593dc095SDavid du Colombier    predicted with good accuracy; the data can then be compressed better than
522*593dc095SDavid du Colombier    with the default empty dictionary.
523*593dc095SDavid du Colombier 
524*593dc095SDavid du Colombier      Depending on the size of the compression data structures selected by
525*593dc095SDavid du Colombier    deflateInit or deflateInit2, a part of the dictionary may in effect be
526*593dc095SDavid du Colombier    discarded, for example if the dictionary is larger than the window size in
527*593dc095SDavid du Colombier    deflate or deflate2. Thus the strings most likely to be useful should be
528*593dc095SDavid du Colombier    put at the end of the dictionary, not at the front.
529*593dc095SDavid du Colombier 
530*593dc095SDavid du Colombier      Upon return of this function, strm->adler is set to the adler32 value
5317dd7cddfSDavid du Colombier    of the dictionary; the decompressor may later use this value to determine
532*593dc095SDavid du Colombier    which dictionary has been used by the compressor. (The adler32 value
5337dd7cddfSDavid du Colombier    applies to the whole dictionary even if only a subset of the dictionary is
534*593dc095SDavid du Colombier    actually used by the compressor.) If a raw deflate was requested, then the
535*593dc095SDavid du Colombier    adler32 value is not computed and strm->adler is not set.
5367dd7cddfSDavid du Colombier 
5377dd7cddfSDavid du Colombier      deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
538*593dc095SDavid du Colombier    parameter is invalid (such as NULL dictionary) or the stream state is
539*593dc095SDavid du Colombier    inconsistent (for example if deflate has already been called for this stream
540*593dc095SDavid du Colombier    or if the compression method is bsort). deflateSetDictionary does not
541*593dc095SDavid du Colombier    perform any compression: this will be done by deflate().
5427dd7cddfSDavid du Colombier */
5437dd7cddfSDavid du Colombier 
544*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
5457dd7cddfSDavid du Colombier                                     z_streamp source));
5467dd7cddfSDavid du Colombier /*
547*593dc095SDavid du Colombier      Sets the destination stream as a complete copy of the source stream.
5487dd7cddfSDavid du Colombier 
5497dd7cddfSDavid du Colombier      This function can be useful when several compression strategies will be
5507dd7cddfSDavid du Colombier    tried, for example when there are several ways of pre-processing the input
5517dd7cddfSDavid du Colombier    data with a filter. The streams that will be discarded should then be freed
5527dd7cddfSDavid du Colombier    by calling deflateEnd.  Note that deflateCopy duplicates the internal
5537dd7cddfSDavid du Colombier    compression state which can be quite large, so this strategy is slow and
5547dd7cddfSDavid du Colombier    can consume lots of memory.
5557dd7cddfSDavid du Colombier 
5567dd7cddfSDavid du Colombier      deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
5577dd7cddfSDavid du Colombier    enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
5587dd7cddfSDavid du Colombier    (such as zalloc being NULL). msg is left unchanged in both source and
5597dd7cddfSDavid du Colombier    destination.
5607dd7cddfSDavid du Colombier */
5617dd7cddfSDavid du Colombier 
562*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
5637dd7cddfSDavid du Colombier /*
5647dd7cddfSDavid du Colombier      This function is equivalent to deflateEnd followed by deflateInit,
5657dd7cddfSDavid du Colombier    but does not free and reallocate all the internal compression state.
5667dd7cddfSDavid du Colombier    The stream will keep the same compression level and any other attributes
5677dd7cddfSDavid du Colombier    that may have been set by deflateInit2.
5687dd7cddfSDavid du Colombier 
5697dd7cddfSDavid du Colombier       deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
5707dd7cddfSDavid du Colombier    stream state was inconsistent (such as zalloc or state being NULL).
5717dd7cddfSDavid du Colombier */
5727dd7cddfSDavid du Colombier 
573*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
574*593dc095SDavid du Colombier                                       int level,
575*593dc095SDavid du Colombier                                       int strategy));
5767dd7cddfSDavid du Colombier /*
577*593dc095SDavid du Colombier      Dynamically update the compression level and compression strategy.  The
578*593dc095SDavid du Colombier    interpretation of level and strategy is as in deflateInit2.  This can be
579*593dc095SDavid du Colombier    used to switch between compression and straight copy of the input data, or
580*593dc095SDavid du Colombier    to switch to a different kind of input data requiring a different
581*593dc095SDavid du Colombier    strategy. If the compression level is changed, the input available so far
582*593dc095SDavid du Colombier    is compressed with the old level (and may be flushed); the new level will
583*593dc095SDavid du Colombier    take effect only at the next call of deflate().
5847dd7cddfSDavid du Colombier 
5857dd7cddfSDavid du Colombier      Before the call of deflateParams, the stream state must be set as for
5867dd7cddfSDavid du Colombier    a call of deflate(), since the currently available input may have to
5877dd7cddfSDavid du Colombier    be compressed and flushed. In particular, strm->avail_out must be non-zero.
5887dd7cddfSDavid du Colombier 
5897dd7cddfSDavid du Colombier      deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
5907dd7cddfSDavid du Colombier    stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
5917dd7cddfSDavid du Colombier    if strm->avail_out was zero.
5927dd7cddfSDavid du Colombier */
5937dd7cddfSDavid du Colombier 
594*593dc095SDavid du Colombier ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
595*593dc095SDavid du Colombier                                        uLong sourceLen));
5967dd7cddfSDavid du Colombier /*
597*593dc095SDavid du Colombier      deflateBound() returns an upper bound on the compressed size after
598*593dc095SDavid du Colombier    deflation of sourceLen bytes.  It must be called after deflateInit()
599*593dc095SDavid du Colombier    or deflateInit2().  This would be used to allocate an output buffer
600*593dc095SDavid du Colombier    for deflation in a single pass, and so would be called before deflate().
601*593dc095SDavid du Colombier */
602*593dc095SDavid du Colombier 
603*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
604*593dc095SDavid du Colombier                                      int bits,
605*593dc095SDavid du Colombier                                      int value));
606*593dc095SDavid du Colombier /*
607*593dc095SDavid du Colombier      deflatePrime() inserts bits in the deflate output stream.  The intent
608*593dc095SDavid du Colombier   is that this function is used to start off the deflate output with the
609*593dc095SDavid du Colombier   bits leftover from a previous deflate stream when appending to it.  As such,
610*593dc095SDavid du Colombier   this function can only be used for raw deflate, and must be used before the
611*593dc095SDavid du Colombier   first deflate() call after a deflateInit2() or deflateReset().  bits must be
612*593dc095SDavid du Colombier   less than or equal to 16, and that many of the least significant bits of
613*593dc095SDavid du Colombier   value will be inserted in the output.
614*593dc095SDavid du Colombier 
615*593dc095SDavid du Colombier       deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
616*593dc095SDavid du Colombier    stream state was inconsistent.
617*593dc095SDavid du Colombier */
618*593dc095SDavid du Colombier 
619*593dc095SDavid du Colombier /*
620*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
6217dd7cddfSDavid du Colombier                                      int  windowBits));
6227dd7cddfSDavid du Colombier 
623*593dc095SDavid du Colombier      This is another version of inflateInit with an extra parameter. The
624*593dc095SDavid du Colombier    fields next_in, avail_in, zalloc, zfree and opaque must be initialized
625*593dc095SDavid du Colombier    before by the caller.
6267dd7cddfSDavid du Colombier 
6277dd7cddfSDavid du Colombier      The windowBits parameter is the base two logarithm of the maximum window
6287dd7cddfSDavid du Colombier    size (the size of the history buffer).  It should be in the range 8..15 for
629*593dc095SDavid du Colombier    this version of the library. The default value is 15 if inflateInit is used
630*593dc095SDavid du Colombier    instead. windowBits must be greater than or equal to the windowBits value
631*593dc095SDavid du Colombier    provided to deflateInit2() while compressing, or it must be equal to 15 if
632*593dc095SDavid du Colombier    deflateInit2() was not used. If a compressed stream with a larger window
633*593dc095SDavid du Colombier    size is given as input, inflate() will return with the error code
634*593dc095SDavid du Colombier    Z_DATA_ERROR instead of trying to allocate a larger window.
6357dd7cddfSDavid du Colombier 
636*593dc095SDavid du Colombier      windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
637*593dc095SDavid du Colombier    determines the window size. inflate() will then process raw deflate data,
638*593dc095SDavid du Colombier    not looking for a zlib or gzip header, not generating a check value, and not
639*593dc095SDavid du Colombier    looking for any check values for comparison at the end of the stream. This
640*593dc095SDavid du Colombier    is for use with other formats that use the deflate compressed data format
641*593dc095SDavid du Colombier    such as zip.  Those formats provide their own check values. If a custom
642*593dc095SDavid du Colombier    format is developed using the raw deflate format for compressed data, it is
643*593dc095SDavid du Colombier    recommended that a check value such as an adler32 or a crc32 be applied to
644*593dc095SDavid du Colombier    the uncompressed data as is done in the zlib, gzip, and zip formats.  For
645*593dc095SDavid du Colombier    most applications, the zlib format should be used as is. Note that comments
646*593dc095SDavid du Colombier    above on the use in deflateInit2() applies to the magnitude of windowBits.
6477dd7cddfSDavid du Colombier 
648*593dc095SDavid du Colombier      windowBits can also be greater than 15 for optional gzip decoding. Add
649*593dc095SDavid du Colombier    32 to windowBits to enable zlib and gzip decoding with automatic header
650*593dc095SDavid du Colombier    detection, or add 16 to decode only the gzip format (the zlib format will
651*593dc095SDavid du Colombier    return a Z_DATA_ERROR.  If a gzip stream is being decoded, strm->adler is
652*593dc095SDavid du Colombier    a crc32 instead of an adler32.
6537dd7cddfSDavid du Colombier 
654*593dc095SDavid du Colombier      inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
655*593dc095SDavid du Colombier    memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
656*593dc095SDavid du Colombier    memLevel). msg is set to null if there is no error message.  inflateInit2
657*593dc095SDavid du Colombier    does not perform any decompression apart from reading the zlib header if
658*593dc095SDavid du Colombier    present: this will be done by inflate(). (So next_in and avail_in may be
659*593dc095SDavid du Colombier    modified, but next_out and avail_out are unchanged.)
6607dd7cddfSDavid du Colombier */
6617dd7cddfSDavid du Colombier 
662*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
6637dd7cddfSDavid du Colombier                                              const Bytef *dictionary,
6647dd7cddfSDavid du Colombier                                              uInt  dictLength));
6657dd7cddfSDavid du Colombier /*
666*593dc095SDavid du Colombier      Initializes the decompression dictionary from the given uncompressed byte
667*593dc095SDavid du Colombier    sequence. This function must be called immediately after a call of inflate
668*593dc095SDavid du Colombier    if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
669*593dc095SDavid du Colombier    can be determined from the adler32 value returned by this call of
670*593dc095SDavid du Colombier    inflate. The compressor and decompressor must use exactly the same
6717dd7cddfSDavid du Colombier    dictionary (see deflateSetDictionary).
6727dd7cddfSDavid du Colombier 
6737dd7cddfSDavid du Colombier      inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
6747dd7cddfSDavid du Colombier    parameter is invalid (such as NULL dictionary) or the stream state is
6757dd7cddfSDavid du Colombier    inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
676*593dc095SDavid du Colombier    expected one (incorrect adler32 value). inflateSetDictionary does not
6777dd7cddfSDavid du Colombier    perform any decompression: this will be done by subsequent calls of
6787dd7cddfSDavid du Colombier    inflate().
6797dd7cddfSDavid du Colombier */
6807dd7cddfSDavid du Colombier 
681*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
6827dd7cddfSDavid du Colombier /*
683*593dc095SDavid du Colombier     Skips invalid compressed data until a full flush point (see above the
684*593dc095SDavid du Colombier   description of deflate with Z_FULL_FLUSH) can be found, or until all
685*593dc095SDavid du Colombier   available input is skipped. No output is provided.
6867dd7cddfSDavid du Colombier 
687*593dc095SDavid du Colombier     inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
688*593dc095SDavid du Colombier   if no more input was provided, Z_DATA_ERROR if no flush point has been found,
6897dd7cddfSDavid du Colombier   or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
6907dd7cddfSDavid du Colombier   case, the application may save the current current value of total_in which
6917dd7cddfSDavid du Colombier   indicates where valid compressed data was found. In the error case, the
6927dd7cddfSDavid du Colombier   application may repeatedly call inflateSync, providing more input each time,
6937dd7cddfSDavid du Colombier   until success or end of the input data.
6947dd7cddfSDavid du Colombier */
6957dd7cddfSDavid du Colombier 
696*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
697*593dc095SDavid du Colombier                                     z_streamp source));
698*593dc095SDavid du Colombier /*
699*593dc095SDavid du Colombier      Sets the destination stream as a complete copy of the source stream.
700*593dc095SDavid du Colombier 
701*593dc095SDavid du Colombier      This function can be useful when randomly accessing a large stream.  The
702*593dc095SDavid du Colombier    first pass through the stream can periodically record the inflate state,
703*593dc095SDavid du Colombier    allowing restarting inflate at those points when randomly accessing the
704*593dc095SDavid du Colombier    stream.
705*593dc095SDavid du Colombier 
706*593dc095SDavid du Colombier      inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
707*593dc095SDavid du Colombier    enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
708*593dc095SDavid du Colombier    (such as zalloc being NULL). msg is left unchanged in both source and
709*593dc095SDavid du Colombier    destination.
710*593dc095SDavid du Colombier */
711*593dc095SDavid du Colombier 
712*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
7137dd7cddfSDavid du Colombier /*
7147dd7cddfSDavid du Colombier      This function is equivalent to inflateEnd followed by inflateInit,
7157dd7cddfSDavid du Colombier    but does not free and reallocate all the internal decompression state.
7167dd7cddfSDavid du Colombier    The stream will keep attributes that may have been set by inflateInit2.
7177dd7cddfSDavid du Colombier 
7187dd7cddfSDavid du Colombier       inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
7197dd7cddfSDavid du Colombier    stream state was inconsistent (such as zalloc or state being NULL).
7207dd7cddfSDavid du Colombier */
7217dd7cddfSDavid du Colombier 
722*593dc095SDavid du Colombier /*
723*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateBackInit OF((z_stream FAR *strm, int windowBits,
724*593dc095SDavid du Colombier                                         unsigned char FAR *window));
725*593dc095SDavid du Colombier 
726*593dc095SDavid du Colombier      Initialize the internal stream state for decompression using inflateBack()
727*593dc095SDavid du Colombier    calls.  The fields zalloc, zfree and opaque in strm must be initialized
728*593dc095SDavid du Colombier    before the call.  If zalloc and zfree are Z_NULL, then the default library-
729*593dc095SDavid du Colombier    derived memory allocation routines are used.  windowBits is the base two
730*593dc095SDavid du Colombier    logarithm of the window size, in the range 8..15.  window is a caller
731*593dc095SDavid du Colombier    supplied buffer of that size.  Except for special applications where it is
732*593dc095SDavid du Colombier    assured that deflate was used with small window sizes, windowBits must be 15
733*593dc095SDavid du Colombier    and a 32K byte window must be supplied to be able to decompress general
734*593dc095SDavid du Colombier    deflate streams.
735*593dc095SDavid du Colombier 
736*593dc095SDavid du Colombier      See inflateBack() for the usage of these routines.
737*593dc095SDavid du Colombier 
738*593dc095SDavid du Colombier      inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
739*593dc095SDavid du Colombier    the paramaters are invalid, Z_MEM_ERROR if the internal state could not
740*593dc095SDavid du Colombier    be allocated, or Z_VERSION_ERROR if the version of the library does not
741*593dc095SDavid du Colombier    match the version of the header file.
742*593dc095SDavid du Colombier */
743*593dc095SDavid du Colombier 
744*593dc095SDavid du Colombier typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
745*593dc095SDavid du Colombier typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
746*593dc095SDavid du Colombier 
747*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateBack OF((z_stream FAR *strm,
748*593dc095SDavid du Colombier                                     in_func in, void FAR *in_desc,
749*593dc095SDavid du Colombier                                     out_func out, void FAR *out_desc));
750*593dc095SDavid du Colombier /*
751*593dc095SDavid du Colombier      inflateBack() does a raw inflate with a single call using a call-back
752*593dc095SDavid du Colombier    interface for input and output.  This is more efficient than inflate() for
753*593dc095SDavid du Colombier    file i/o applications in that it avoids copying between the output and the
754*593dc095SDavid du Colombier    sliding window by simply making the window itself the output buffer.  This
755*593dc095SDavid du Colombier    function trusts the application to not change the output buffer passed by
756*593dc095SDavid du Colombier    the output function, at least until inflateBack() returns.
757*593dc095SDavid du Colombier 
758*593dc095SDavid du Colombier      inflateBackInit() must be called first to allocate the internal state
759*593dc095SDavid du Colombier    and to initialize the state with the user-provided window buffer.
760*593dc095SDavid du Colombier    inflateBack() may then be used multiple times to inflate a complete, raw
761*593dc095SDavid du Colombier    deflate stream with each call.  inflateBackEnd() is then called to free
762*593dc095SDavid du Colombier    the allocated state.
763*593dc095SDavid du Colombier 
764*593dc095SDavid du Colombier      A raw deflate stream is one with no zlib or gzip header or trailer.
765*593dc095SDavid du Colombier    This routine would normally be used in a utility that reads zip or gzip
766*593dc095SDavid du Colombier    files and writes out uncompressed files.  The utility would decode the
767*593dc095SDavid du Colombier    header and process the trailer on its own, hence this routine expects
768*593dc095SDavid du Colombier    only the raw deflate stream to decompress.  This is different from the
769*593dc095SDavid du Colombier    normal behavior of inflate(), which expects either a zlib or gzip header and
770*593dc095SDavid du Colombier    trailer around the deflate stream.
771*593dc095SDavid du Colombier 
772*593dc095SDavid du Colombier      inflateBack() uses two subroutines supplied by the caller that are then
773*593dc095SDavid du Colombier    called by inflateBack() for input and output.  inflateBack() calls those
774*593dc095SDavid du Colombier    routines until it reads a complete deflate stream and writes out all of the
775*593dc095SDavid du Colombier    uncompressed data, or until it encounters an error.  The function's
776*593dc095SDavid du Colombier    parameters and return types are defined above in the in_func and out_func
777*593dc095SDavid du Colombier    typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
778*593dc095SDavid du Colombier    number of bytes of provided input, and a pointer to that input in buf.  If
779*593dc095SDavid du Colombier    there is no input available, in() must return zero--buf is ignored in that
780*593dc095SDavid du Colombier    case--and inflateBack() will return a buffer error.  inflateBack() will call
781*593dc095SDavid du Colombier    out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].  out()
782*593dc095SDavid du Colombier    should return zero on success, or non-zero on failure.  If out() returns
783*593dc095SDavid du Colombier    non-zero, inflateBack() will return with an error.  Neither in() nor out()
784*593dc095SDavid du Colombier    are permitted to change the contents of the window provided to
785*593dc095SDavid du Colombier    inflateBackInit(), which is also the buffer that out() uses to write from.
786*593dc095SDavid du Colombier    The length written by out() will be at most the window size.  Any non-zero
787*593dc095SDavid du Colombier    amount of input may be provided by in().
788*593dc095SDavid du Colombier 
789*593dc095SDavid du Colombier      For convenience, inflateBack() can be provided input on the first call by
790*593dc095SDavid du Colombier    setting strm->next_in and strm->avail_in.  If that input is exhausted, then
791*593dc095SDavid du Colombier    in() will be called.  Therefore strm->next_in must be initialized before
792*593dc095SDavid du Colombier    calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
793*593dc095SDavid du Colombier    immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
794*593dc095SDavid du Colombier    must also be initialized, and then if strm->avail_in is not zero, input will
795*593dc095SDavid du Colombier    initially be taken from strm->next_in[0 .. strm->avail_in - 1].
796*593dc095SDavid du Colombier 
797*593dc095SDavid du Colombier      The in_desc and out_desc parameters of inflateBack() is passed as the
798*593dc095SDavid du Colombier    first parameter of in() and out() respectively when they are called.  These
799*593dc095SDavid du Colombier    descriptors can be optionally used to pass any information that the caller-
800*593dc095SDavid du Colombier    supplied in() and out() functions need to do their job.
801*593dc095SDavid du Colombier 
802*593dc095SDavid du Colombier      On return, inflateBack() will set strm->next_in and strm->avail_in to
803*593dc095SDavid du Colombier    pass back any unused input that was provided by the last in() call.  The
804*593dc095SDavid du Colombier    return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
805*593dc095SDavid du Colombier    if in() or out() returned an error, Z_DATA_ERROR if there was a format
806*593dc095SDavid du Colombier    error in the deflate stream (in which case strm->msg is set to indicate the
807*593dc095SDavid du Colombier    nature of the error), or Z_STREAM_ERROR if the stream was not properly
808*593dc095SDavid du Colombier    initialized.  In the case of Z_BUF_ERROR, an input or output error can be
809*593dc095SDavid du Colombier    distinguished using strm->next_in which will be Z_NULL only if in() returned
810*593dc095SDavid du Colombier    an error.  If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
811*593dc095SDavid du Colombier    out() returning non-zero.  (in() will always be called before out(), so
812*593dc095SDavid du Colombier    strm->next_in is assured to be defined if out() returns non-zero.)  Note
813*593dc095SDavid du Colombier    that inflateBack() cannot return Z_OK.
814*593dc095SDavid du Colombier */
815*593dc095SDavid du Colombier 
816*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateBackEnd OF((z_stream FAR *strm));
817*593dc095SDavid du Colombier /*
818*593dc095SDavid du Colombier      All memory allocated by inflateBackInit() is freed.
819*593dc095SDavid du Colombier 
820*593dc095SDavid du Colombier      inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
821*593dc095SDavid du Colombier    state was inconsistent.
822*593dc095SDavid du Colombier */
823*593dc095SDavid du Colombier 
824*593dc095SDavid du Colombier ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
825*593dc095SDavid du Colombier /* Return flags indicating compile-time options.
826*593dc095SDavid du Colombier 
827*593dc095SDavid du Colombier     Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
828*593dc095SDavid du Colombier      1.0: size of uInt
829*593dc095SDavid du Colombier      3.2: size of uLong
830*593dc095SDavid du Colombier      5.4: size of voidpf (pointer)
831*593dc095SDavid du Colombier      7.6: size of z_off_t
832*593dc095SDavid du Colombier 
833*593dc095SDavid du Colombier     Compiler, assembler, and debug options:
834*593dc095SDavid du Colombier      8: DEBUG
835*593dc095SDavid du Colombier      9: ASMV or ASMINF -- use ASM code
836*593dc095SDavid du Colombier      10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
837*593dc095SDavid du Colombier      11: 0 (reserved)
838*593dc095SDavid du Colombier 
839*593dc095SDavid du Colombier     One-time table building (smaller code, but not thread-safe if true):
840*593dc095SDavid du Colombier      12: BUILDFIXED -- build static block decoding tables when needed
841*593dc095SDavid du Colombier      13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
842*593dc095SDavid du Colombier      14,15: 0 (reserved)
843*593dc095SDavid du Colombier 
844*593dc095SDavid du Colombier     Library content (indicates missing functionality):
845*593dc095SDavid du Colombier      16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
846*593dc095SDavid du Colombier                           deflate code when not needed)
847*593dc095SDavid du Colombier      17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
848*593dc095SDavid du Colombier                     and decode gzip streams (to avoid linking crc code)
849*593dc095SDavid du Colombier      18-19: 0 (reserved)
850*593dc095SDavid du Colombier 
851*593dc095SDavid du Colombier     Operation variations (changes in library functionality):
852*593dc095SDavid du Colombier      20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
853*593dc095SDavid du Colombier      21: FASTEST -- deflate algorithm with only one, lowest compression level
854*593dc095SDavid du Colombier      22,23: 0 (reserved)
855*593dc095SDavid du Colombier 
856*593dc095SDavid du Colombier     The sprintf variant used by gzprintf (zero is best):
857*593dc095SDavid du Colombier      24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
858*593dc095SDavid du Colombier      25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
859*593dc095SDavid du Colombier      26: 0 = returns value, 1 = void -- 1 means inferred string length returned
860*593dc095SDavid du Colombier 
861*593dc095SDavid du Colombier     Remainder:
862*593dc095SDavid du Colombier      27-31: 0 (reserved)
863*593dc095SDavid du Colombier  */
864*593dc095SDavid du Colombier 
8657dd7cddfSDavid du Colombier 
8667dd7cddfSDavid du Colombier                         /* utility functions */
8677dd7cddfSDavid du Colombier 
8687dd7cddfSDavid du Colombier /*
8697dd7cddfSDavid du Colombier      The following utility functions are implemented on top of the
8707dd7cddfSDavid du Colombier    basic stream-oriented functions. To simplify the interface, some
871*593dc095SDavid du Colombier    default options are assumed (compression level and memory usage,
8727dd7cddfSDavid du Colombier    standard memory allocation functions). The source code of these
8737dd7cddfSDavid du Colombier    utility functions can easily be modified if you need special options.
8747dd7cddfSDavid du Colombier */
8757dd7cddfSDavid du Colombier 
876*593dc095SDavid du Colombier ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
8777dd7cddfSDavid du Colombier                                  const Bytef *source, uLong sourceLen));
8787dd7cddfSDavid du Colombier /*
8797dd7cddfSDavid du Colombier      Compresses the source buffer into the destination buffer.  sourceLen is
8807dd7cddfSDavid du Colombier    the byte length of the source buffer. Upon entry, destLen is the total
881*593dc095SDavid du Colombier    size of the destination buffer, which must be at least the value returned
882*593dc095SDavid du Colombier    by compressBound(sourceLen). Upon exit, destLen is the actual size of the
8837dd7cddfSDavid du Colombier    compressed buffer.
8847dd7cddfSDavid du Colombier      This function can be used to compress a whole file at once if the
8857dd7cddfSDavid du Colombier    input file is mmap'ed.
8867dd7cddfSDavid du Colombier      compress returns Z_OK if success, Z_MEM_ERROR if there was not
8877dd7cddfSDavid du Colombier    enough memory, Z_BUF_ERROR if there was not enough room in the output
8887dd7cddfSDavid du Colombier    buffer.
8897dd7cddfSDavid du Colombier */
8907dd7cddfSDavid du Colombier 
891*593dc095SDavid du Colombier ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
892*593dc095SDavid du Colombier                                   const Bytef *source, uLong sourceLen,
893*593dc095SDavid du Colombier                                   int level));
894*593dc095SDavid du Colombier /*
895*593dc095SDavid du Colombier      Compresses the source buffer into the destination buffer. The level
896*593dc095SDavid du Colombier    parameter has the same meaning as in deflateInit.  sourceLen is the byte
897*593dc095SDavid du Colombier    length of the source buffer. Upon entry, destLen is the total size of the
898*593dc095SDavid du Colombier    destination buffer, which must be at least the value returned by
899*593dc095SDavid du Colombier    compressBound(sourceLen). Upon exit, destLen is the actual size of the
900*593dc095SDavid du Colombier    compressed buffer.
901*593dc095SDavid du Colombier 
902*593dc095SDavid du Colombier      compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
903*593dc095SDavid du Colombier    memory, Z_BUF_ERROR if there was not enough room in the output buffer,
904*593dc095SDavid du Colombier    Z_STREAM_ERROR if the level parameter is invalid.
905*593dc095SDavid du Colombier */
906*593dc095SDavid du Colombier 
907*593dc095SDavid du Colombier ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
908*593dc095SDavid du Colombier /*
909*593dc095SDavid du Colombier      compressBound() returns an upper bound on the compressed size after
910*593dc095SDavid du Colombier    compress() or compress2() on sourceLen bytes.  It would be used before
911*593dc095SDavid du Colombier    a compress() or compress2() call to allocate the destination buffer.
912*593dc095SDavid du Colombier */
913*593dc095SDavid du Colombier 
914*593dc095SDavid du Colombier ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
9157dd7cddfSDavid du Colombier                                    const Bytef *source, uLong sourceLen));
9167dd7cddfSDavid du Colombier /*
9177dd7cddfSDavid du Colombier      Decompresses the source buffer into the destination buffer.  sourceLen is
9187dd7cddfSDavid du Colombier    the byte length of the source buffer. Upon entry, destLen is the total
9197dd7cddfSDavid du Colombier    size of the destination buffer, which must be large enough to hold the
9207dd7cddfSDavid du Colombier    entire uncompressed data. (The size of the uncompressed data must have
9217dd7cddfSDavid du Colombier    been saved previously by the compressor and transmitted to the decompressor
9227dd7cddfSDavid du Colombier    by some mechanism outside the scope of this compression library.)
9237dd7cddfSDavid du Colombier    Upon exit, destLen is the actual size of the compressed buffer.
9247dd7cddfSDavid du Colombier      This function can be used to decompress a whole file at once if the
9257dd7cddfSDavid du Colombier    input file is mmap'ed.
9267dd7cddfSDavid du Colombier 
9277dd7cddfSDavid du Colombier      uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
9287dd7cddfSDavid du Colombier    enough memory, Z_BUF_ERROR if there was not enough room in the output
929*593dc095SDavid du Colombier    buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
9307dd7cddfSDavid du Colombier */
9317dd7cddfSDavid du Colombier 
9327dd7cddfSDavid du Colombier 
9337dd7cddfSDavid du Colombier typedef voidp gzFile;
9347dd7cddfSDavid du Colombier 
935*593dc095SDavid du Colombier ZEXTERN gzFile ZEXPORT gzopen  OF((const char *path, const char *mode));
9367dd7cddfSDavid du Colombier /*
9377dd7cddfSDavid du Colombier      Opens a gzip (.gz) file for reading or writing. The mode parameter
9387dd7cddfSDavid du Colombier    is as in fopen ("rb" or "wb") but can also include a compression level
939*593dc095SDavid du Colombier    ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
940*593dc095SDavid du Colombier    Huffman only compression as in "wb1h", or 'R' for run-length encoding
941*593dc095SDavid du Colombier    as in "wb1R". (See the description of deflateInit2 for more information
942*593dc095SDavid du Colombier    about the strategy parameter.)
943*593dc095SDavid du Colombier 
944*593dc095SDavid du Colombier      gzopen can be used to read a file which is not in gzip format; in this
945*593dc095SDavid du Colombier    case gzread will directly read from the file without decompression.
946*593dc095SDavid du Colombier 
9477dd7cddfSDavid du Colombier      gzopen returns NULL if the file could not be opened or if there was
9487dd7cddfSDavid du Colombier    insufficient memory to allocate the (de)compression state; errno
9497dd7cddfSDavid du Colombier    can be checked to distinguish the two cases (if errno is zero, the
950*593dc095SDavid du Colombier    zlib error is Z_MEM_ERROR).  */
9517dd7cddfSDavid du Colombier 
952*593dc095SDavid du Colombier ZEXTERN gzFile ZEXPORT gzdopen  OF((int fd, const char *mode));
9537dd7cddfSDavid du Colombier /*
9547dd7cddfSDavid du Colombier      gzdopen() associates a gzFile with the file descriptor fd.  File
9557dd7cddfSDavid du Colombier    descriptors are obtained from calls like open, dup, creat, pipe or
9567dd7cddfSDavid du Colombier    fileno (in the file has been previously opened with fopen).
9577dd7cddfSDavid du Colombier    The mode parameter is as in gzopen.
9587dd7cddfSDavid du Colombier      The next call of gzclose on the returned gzFile will also close the
9597dd7cddfSDavid du Colombier    file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
9607dd7cddfSDavid du Colombier    descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
9617dd7cddfSDavid du Colombier      gzdopen returns NULL if there was insufficient memory to allocate
9627dd7cddfSDavid du Colombier    the (de)compression state.
9637dd7cddfSDavid du Colombier */
9647dd7cddfSDavid du Colombier 
965*593dc095SDavid du Colombier ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
966*593dc095SDavid du Colombier /*
967*593dc095SDavid du Colombier      Dynamically update the compression level or strategy. See the description
968*593dc095SDavid du Colombier    of deflateInit2 for the meaning of these parameters.
969*593dc095SDavid du Colombier      gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
970*593dc095SDavid du Colombier    opened for writing.
971*593dc095SDavid du Colombier */
972*593dc095SDavid du Colombier 
973*593dc095SDavid du Colombier ZEXTERN int ZEXPORT    gzread  OF((gzFile file, voidp buf, unsigned len));
9747dd7cddfSDavid du Colombier /*
9757dd7cddfSDavid du Colombier      Reads the given number of uncompressed bytes from the compressed file.
9767dd7cddfSDavid du Colombier    If the input file was not in gzip format, gzread copies the given number
9777dd7cddfSDavid du Colombier    of bytes into the buffer.
9787dd7cddfSDavid du Colombier      gzread returns the number of uncompressed bytes actually read (0 for
9797dd7cddfSDavid du Colombier    end of file, -1 for error). */
9807dd7cddfSDavid du Colombier 
981*593dc095SDavid du Colombier ZEXTERN int ZEXPORT    gzwrite OF((gzFile file,
982*593dc095SDavid du Colombier                                    voidpc buf, unsigned len));
9837dd7cddfSDavid du Colombier /*
9847dd7cddfSDavid du Colombier      Writes the given number of uncompressed bytes into the compressed file.
9857dd7cddfSDavid du Colombier    gzwrite returns the number of uncompressed bytes actually written
9867dd7cddfSDavid du Colombier    (0 in case of error).
9877dd7cddfSDavid du Colombier */
9887dd7cddfSDavid du Colombier 
989*593dc095SDavid du Colombier ZEXTERN int ZEXPORTVA   gzprintf OF((gzFile file, const char *format, ...));
990*593dc095SDavid du Colombier /*
991*593dc095SDavid du Colombier      Converts, formats, and writes the args to the compressed file under
992*593dc095SDavid du Colombier    control of the format string, as in fprintf. gzprintf returns the number of
993*593dc095SDavid du Colombier    uncompressed bytes actually written (0 in case of error).  The number of
994*593dc095SDavid du Colombier    uncompressed bytes written is limited to 4095. The caller should assure that
995*593dc095SDavid du Colombier    this limit is not exceeded. If it is exceeded, then gzprintf() will return
996*593dc095SDavid du Colombier    return an error (0) with nothing written. In this case, there may also be a
997*593dc095SDavid du Colombier    buffer overflow with unpredictable consequences, which is possible only if
998*593dc095SDavid du Colombier    zlib was compiled with the insecure functions sprintf() or vsprintf()
999*593dc095SDavid du Colombier    because the secure snprintf() or vsnprintf() functions were not available.
1000*593dc095SDavid du Colombier */
1001*593dc095SDavid du Colombier 
1002*593dc095SDavid du Colombier ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
1003*593dc095SDavid du Colombier /*
1004*593dc095SDavid du Colombier       Writes the given null-terminated string to the compressed file, excluding
1005*593dc095SDavid du Colombier    the terminating null character.
1006*593dc095SDavid du Colombier       gzputs returns the number of characters written, or -1 in case of error.
1007*593dc095SDavid du Colombier */
1008*593dc095SDavid du Colombier 
1009*593dc095SDavid du Colombier ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
1010*593dc095SDavid du Colombier /*
1011*593dc095SDavid du Colombier       Reads bytes from the compressed file until len-1 characters are read, or
1012*593dc095SDavid du Colombier    a newline character is read and transferred to buf, or an end-of-file
1013*593dc095SDavid du Colombier    condition is encountered.  The string is then terminated with a null
1014*593dc095SDavid du Colombier    character.
1015*593dc095SDavid du Colombier       gzgets returns buf, or Z_NULL in case of error.
1016*593dc095SDavid du Colombier */
1017*593dc095SDavid du Colombier 
1018*593dc095SDavid du Colombier ZEXTERN int ZEXPORT    gzputc OF((gzFile file, int c));
1019*593dc095SDavid du Colombier /*
1020*593dc095SDavid du Colombier       Writes c, converted to an unsigned char, into the compressed file.
1021*593dc095SDavid du Colombier    gzputc returns the value that was written, or -1 in case of error.
1022*593dc095SDavid du Colombier */
1023*593dc095SDavid du Colombier 
1024*593dc095SDavid du Colombier ZEXTERN int ZEXPORT    gzgetc OF((gzFile file));
1025*593dc095SDavid du Colombier /*
1026*593dc095SDavid du Colombier       Reads one byte from the compressed file. gzgetc returns this byte
1027*593dc095SDavid du Colombier    or -1 in case of end of file or error.
1028*593dc095SDavid du Colombier */
1029*593dc095SDavid du Colombier 
1030*593dc095SDavid du Colombier ZEXTERN int ZEXPORT    gzungetc OF((int c, gzFile file));
1031*593dc095SDavid du Colombier /*
1032*593dc095SDavid du Colombier       Push one character back onto the stream to be read again later.
1033*593dc095SDavid du Colombier    Only one character of push-back is allowed.  gzungetc() returns the
1034*593dc095SDavid du Colombier    character pushed, or -1 on failure.  gzungetc() will fail if a
1035*593dc095SDavid du Colombier    character has been pushed but not read yet, or if c is -1. The pushed
1036*593dc095SDavid du Colombier    character will be discarded if the stream is repositioned with gzseek()
1037*593dc095SDavid du Colombier    or gzrewind().
1038*593dc095SDavid du Colombier */
1039*593dc095SDavid du Colombier 
1040*593dc095SDavid du Colombier ZEXTERN int ZEXPORT    gzflush OF((gzFile file, int flush));
10417dd7cddfSDavid du Colombier /*
10427dd7cddfSDavid du Colombier      Flushes all pending output into the compressed file. The parameter
10437dd7cddfSDavid du Colombier    flush is as in the deflate() function. The return value is the zlib
10447dd7cddfSDavid du Colombier    error number (see function gzerror below). gzflush returns Z_OK if
10457dd7cddfSDavid du Colombier    the flush parameter is Z_FINISH and all output could be flushed.
10467dd7cddfSDavid du Colombier      gzflush should be called only when strictly necessary because it can
10477dd7cddfSDavid du Colombier    degrade compression.
10487dd7cddfSDavid du Colombier */
10497dd7cddfSDavid du Colombier 
1050*593dc095SDavid du Colombier ZEXTERN z_off_t ZEXPORT    gzseek OF((gzFile file,
1051*593dc095SDavid du Colombier                                       z_off_t offset, int whence));
1052*593dc095SDavid du Colombier /*
1053*593dc095SDavid du Colombier       Sets the starting position for the next gzread or gzwrite on the
1054*593dc095SDavid du Colombier    given compressed file. The offset represents a number of bytes in the
1055*593dc095SDavid du Colombier    uncompressed data stream. The whence parameter is defined as in lseek(2);
1056*593dc095SDavid du Colombier    the value SEEK_END is not supported.
1057*593dc095SDavid du Colombier      If the file is opened for reading, this function is emulated but can be
1058*593dc095SDavid du Colombier    extremely slow. If the file is opened for writing, only forward seeks are
1059*593dc095SDavid du Colombier    supported; gzseek then compresses a sequence of zeroes up to the new
1060*593dc095SDavid du Colombier    starting position.
1061*593dc095SDavid du Colombier 
1062*593dc095SDavid du Colombier       gzseek returns the resulting offset location as measured in bytes from
1063*593dc095SDavid du Colombier    the beginning of the uncompressed stream, or -1 in case of error, in
1064*593dc095SDavid du Colombier    particular if the file is opened for writing and the new starting position
1065*593dc095SDavid du Colombier    would be before the current position.
1066*593dc095SDavid du Colombier */
1067*593dc095SDavid du Colombier 
1068*593dc095SDavid du Colombier ZEXTERN int ZEXPORT    gzrewind OF((gzFile file));
1069*593dc095SDavid du Colombier /*
1070*593dc095SDavid du Colombier      Rewinds the given file. This function is supported only for reading.
1071*593dc095SDavid du Colombier 
1072*593dc095SDavid du Colombier    gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
1073*593dc095SDavid du Colombier */
1074*593dc095SDavid du Colombier 
1075*593dc095SDavid du Colombier ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
1076*593dc095SDavid du Colombier /*
1077*593dc095SDavid du Colombier      Returns the starting position for the next gzread or gzwrite on the
1078*593dc095SDavid du Colombier    given compressed file. This position represents a number of bytes in the
1079*593dc095SDavid du Colombier    uncompressed data stream.
1080*593dc095SDavid du Colombier 
1081*593dc095SDavid du Colombier    gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
1082*593dc095SDavid du Colombier */
1083*593dc095SDavid du Colombier 
1084*593dc095SDavid du Colombier ZEXTERN int ZEXPORT gzeof OF((gzFile file));
1085*593dc095SDavid du Colombier /*
1086*593dc095SDavid du Colombier      Returns 1 when EOF has previously been detected reading the given
1087*593dc095SDavid du Colombier    input stream, otherwise zero.
1088*593dc095SDavid du Colombier */
1089*593dc095SDavid du Colombier 
1090*593dc095SDavid du Colombier ZEXTERN int ZEXPORT    gzclose OF((gzFile file));
10917dd7cddfSDavid du Colombier /*
10927dd7cddfSDavid du Colombier      Flushes all pending output if necessary, closes the compressed file
10937dd7cddfSDavid du Colombier    and deallocates all the (de)compression state. The return value is the zlib
10947dd7cddfSDavid du Colombier    error number (see function gzerror below).
10957dd7cddfSDavid du Colombier */
10967dd7cddfSDavid du Colombier 
1097*593dc095SDavid du Colombier ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
10987dd7cddfSDavid du Colombier /*
10997dd7cddfSDavid du Colombier      Returns the error message for the last error which occurred on the
11007dd7cddfSDavid du Colombier    given compressed file. errnum is set to zlib error number. If an
11017dd7cddfSDavid du Colombier    error occurred in the file system and not in the compression library,
11027dd7cddfSDavid du Colombier    errnum is set to Z_ERRNO and the application may consult errno
11037dd7cddfSDavid du Colombier    to get the exact error code.
11047dd7cddfSDavid du Colombier */
11057dd7cddfSDavid du Colombier 
1106*593dc095SDavid du Colombier ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
1107*593dc095SDavid du Colombier /*
1108*593dc095SDavid du Colombier      Clears the error and end-of-file flags for file. This is analogous to the
1109*593dc095SDavid du Colombier    clearerr() function in stdio. This is useful for continuing to read a gzip
1110*593dc095SDavid du Colombier    file that is being written concurrently.
1111*593dc095SDavid du Colombier */
1112*593dc095SDavid du Colombier 
11137dd7cddfSDavid du Colombier                         /* checksum functions */
11147dd7cddfSDavid du Colombier 
11157dd7cddfSDavid du Colombier /*
11167dd7cddfSDavid du Colombier      These functions are not related to compression but are exported
11177dd7cddfSDavid du Colombier    anyway because they might be useful in applications using the
11187dd7cddfSDavid du Colombier    compression library.
11197dd7cddfSDavid du Colombier */
11207dd7cddfSDavid du Colombier 
1121*593dc095SDavid du Colombier ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
11227dd7cddfSDavid du Colombier 
11237dd7cddfSDavid du Colombier /*
11247dd7cddfSDavid du Colombier      Update a running Adler-32 checksum with the bytes buf[0..len-1] and
11257dd7cddfSDavid du Colombier    return the updated checksum. If buf is NULL, this function returns
11267dd7cddfSDavid du Colombier    the required initial value for the checksum.
11277dd7cddfSDavid du Colombier    An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
11287dd7cddfSDavid du Colombier    much faster. Usage example:
11297dd7cddfSDavid du Colombier 
11307dd7cddfSDavid du Colombier      uLong adler = adler32(0L, Z_NULL, 0);
11317dd7cddfSDavid du Colombier 
11327dd7cddfSDavid du Colombier      while (read_buffer(buffer, length) != EOF) {
11337dd7cddfSDavid du Colombier        adler = adler32(adler, buffer, length);
11347dd7cddfSDavid du Colombier      }
11357dd7cddfSDavid du Colombier      if (adler != original_adler) error();
11367dd7cddfSDavid du Colombier */
11377dd7cddfSDavid du Colombier 
1138*593dc095SDavid du Colombier ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
11397dd7cddfSDavid du Colombier /*
11407dd7cddfSDavid du Colombier      Update a running crc with the bytes buf[0..len-1] and return the updated
11417dd7cddfSDavid du Colombier    crc. If buf is NULL, this function returns the required initial value
11427dd7cddfSDavid du Colombier    for the crc. Pre- and post-conditioning (one's complement) is performed
11437dd7cddfSDavid du Colombier    within this function so it shouldn't be done by the application.
11447dd7cddfSDavid du Colombier    Usage example:
11457dd7cddfSDavid du Colombier 
11467dd7cddfSDavid du Colombier      uLong crc = crc32(0L, Z_NULL, 0);
11477dd7cddfSDavid du Colombier 
11487dd7cddfSDavid du Colombier      while (read_buffer(buffer, length) != EOF) {
11497dd7cddfSDavid du Colombier        crc = crc32(crc, buffer, length);
11507dd7cddfSDavid du Colombier      }
11517dd7cddfSDavid du Colombier      if (crc != original_crc) error();
11527dd7cddfSDavid du Colombier */
11537dd7cddfSDavid du Colombier 
11547dd7cddfSDavid du Colombier 
11557dd7cddfSDavid du Colombier                         /* various hacks, don't look :) */
11567dd7cddfSDavid du Colombier 
11577dd7cddfSDavid du Colombier /* deflateInit and inflateInit are macros to allow checking the zlib version
11587dd7cddfSDavid du Colombier  * and the compiler's view of z_stream:
11597dd7cddfSDavid du Colombier  */
1160*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
11617dd7cddfSDavid du Colombier                                      const char *version, int stream_size));
1162*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
11637dd7cddfSDavid du Colombier                                      const char *version, int stream_size));
1164*593dc095SDavid du Colombier ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
1165*593dc095SDavid du Colombier                                       int windowBits, int memLevel,
1166*593dc095SDavid du Colombier                                       int strategy, const char *version,
1167*593dc095SDavid du Colombier                                       int stream_size));
1168*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
11697dd7cddfSDavid du Colombier                                       const char *version, int stream_size));
1170*593dc095SDavid du Colombier ZEXTERN int ZEXPORT inflateBackInit_ OF((z_stream FAR *strm, int windowBits,
1171*593dc095SDavid du Colombier                                          unsigned char FAR *window,
1172*593dc095SDavid du Colombier                                          const char *version,
1173*593dc095SDavid du Colombier                                          int stream_size));
11747dd7cddfSDavid du Colombier #define deflateInit(strm, level) \
11757dd7cddfSDavid du Colombier         deflateInit_((strm), (level),       ZLIB_VERSION, sizeof(z_stream))
11767dd7cddfSDavid du Colombier #define inflateInit(strm) \
11777dd7cddfSDavid du Colombier         inflateInit_((strm),                ZLIB_VERSION, sizeof(z_stream))
11787dd7cddfSDavid du Colombier #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
11797dd7cddfSDavid du Colombier         deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
11807dd7cddfSDavid du Colombier                       (strategy),           ZLIB_VERSION, sizeof(z_stream))
11817dd7cddfSDavid du Colombier #define inflateInit2(strm, windowBits) \
11827dd7cddfSDavid du Colombier         inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
1183*593dc095SDavid du Colombier #define inflateBackInit(strm, windowBits, window) \
1184*593dc095SDavid du Colombier         inflateBackInit_((strm), (windowBits), (window), \
1185*593dc095SDavid du Colombier         ZLIB_VERSION, sizeof(z_stream))
11867dd7cddfSDavid du Colombier 
1187*593dc095SDavid du Colombier 
1188*593dc095SDavid du Colombier #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
11897dd7cddfSDavid du Colombier     struct internal_state {int dummy;}; /* hack for buggy compilers */
11907dd7cddfSDavid du Colombier #endif
11917dd7cddfSDavid du Colombier 
1192*593dc095SDavid du Colombier ZEXTERN const char   * ZEXPORT zError           OF((int));
1193*593dc095SDavid du Colombier ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp z));
1194*593dc095SDavid du Colombier ZEXTERN const uLongf * ZEXPORT get_crc_table    OF((void));
11957dd7cddfSDavid du Colombier 
11967dd7cddfSDavid du Colombier #ifdef __cplusplus
11977dd7cddfSDavid du Colombier }
11987dd7cddfSDavid du Colombier #endif
11997dd7cddfSDavid du Colombier 
1200*593dc095SDavid du Colombier #endif /* ZLIB_H */
1201