include/linux/zlib.h

1 /* zlib.h -- interface of the 'zlib' general purpose compression library
3   Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
5   This software is provided 'as-is', without any express or implied
21   Jean-loup Gailly        Mark Adler
53      The 'zlib' compression library provides in-memory compression and
65      The compressed data format used by default by the in-memory functions is
73   and on communications channels.  The gzip format was designed for single-
113    parameter for calls of zalloc and zfree. This can be useful for custom
118    If zlib is used in a multi-threaded application, zalloc and zfree must be
121    On 16-bit systems, the functions zalloc and zfree must be able to allocate
128    compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
151 #define Z_ERRNO        (-1)
152 #define Z_STREAM_ERROR (-2)
153 #define Z_DATA_ERROR   (-3)
154 #define Z_MEM_ERROR    (-4)
155 #define Z_BUF_ERROR    (-5)
156 #define Z_VERSION_ERROR (-6)
164 #define Z_DEFAULT_COMPRESSION  (-1)
184    Returns the number of bytes that needs to be allocated for a per-
186    number of bytes should be returned in stream->workspace before
196    Returns 1 if Deflate-Conversion facility is installed and enabled,
233   - Compress more input starting at next_in and update next_in and avail_in
238   - Provide more output starting at next_out and update next_out and avail_out
239     accordingly. This action is forced if the parameter flush is non zero.
240     Forcing flush frequently degrades the compression ratio, so this parameter
253     If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
267   with the same value of the flush parameter and more output space (updated
268   avail_out), until the flush is complete (deflate returns with non-zero
271     If the parameter flush is set to Z_FINISH, pending input is processed,
284     deflate() sets strm->adler to the adler32 checksum of all input read
317    Returns the number of bytes that needs to be allocated for a per-
319    returned in stream->workspace before calling zlib_inflateInit().
353   - Decompress more input starting at next_in and update next_in and avail_in
358   - Provide more output starting at next_out and update next_out and avail_out
361     about the flush parameter).
372     The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
382   Also to assist in this, on return inflate() will set strm->data_type to the
383   number of unused bits in the last byte taken from strm->next_in, plus 64
385   plus 128 if inflate() returned immediately after decoding an end-of-block
387   deflate stream. The end-of-block will not be indicated until all of the
388   uncompressed data from that block has been written to strm->next_out.  The
391   less than eight.
395   (a single call of inflate), the parameter flush should be set to
406   first call. So the only effect of the flush parameter in this implementation
411   below), inflate sets strm->adler to the adler32 checksum of the dictionary
413   strm->adler to the adler32 checksum of all output produced so far (that is,
419     inflate() will decompress and check either zlib-wrapped or gzip-wrapped
471      The method parameter is the compression method. It must be Z_DEFLATED in
474      The windowBits parameter is the base two logarithm of the window size
476    version of the library. Larger values of this parameter result in better
480      The memLevel parameter specifies how much memory should be allocated
486      The strategy parameter is used to tune the compression algorithm. Use the
492    Huffman coding and less string matching; it is somewhat intermediate
493    between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects
498    memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
522      This is another version of inflateInit with an extra parameter. The
526      The windowBits parameter is the base two logarithm of the maximum window
535      windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
550    return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is
554    memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg