path: root/include/linux/zlib.h

/* zlib.h -- interface of the 'zlib' general purpose compression library

  Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.

  Jean-loup Gailly        Mark Adler
  jloup@gzip.org          madler@alumni.caltech.edu


  The data format used by the zlib library is described by RFCs (Request for
  Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
  (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
*/

#ifndef _ZLIB_H
#define _ZLIB_H

#include <linux/zconf.h>




struct internal_state;

typedef struct z_stream_s {
    const Byte *next_in;   
    uInt     avail_in;  
    uLong    total_in;  

    Byte    *next_out;  
    uInt     avail_out; 
    uLong    total_out; 

    char     *msg;      
    struct internal_state *state; 

    void     *workspace; 

    int     data_type;  
    uLong   adler;      
    uLong   reserved;   
} z_stream;

typedef z_stream *z_streamp;


                        

#define Z_NO_FLUSH      0
#define Z_PARTIAL_FLUSH 1 
#define Z_PACKET_FLUSH  2
#define Z_SYNC_FLUSH    3
#define Z_FULL_FLUSH    4
#define Z_FINISH        5
#define Z_BLOCK         6 

#define Z_OK            0
#define Z_STREAM_END    1
#define Z_NEED_DICT     2
#define Z_ERRNO        (-1)
#define Z_STREAM_ERROR (-2)
#define Z_DATA_ERROR   (-3)
#define Z_MEM_ERROR    (-4)
#define Z_BUF_ERROR    (-5)
#define Z_VERSION_ERROR (-6)

#define Z_NO_COMPRESSION         0
#define Z_BEST_SPEED             1
#define Z_BEST_COMPRESSION       9
#define Z_DEFAULT_COMPRESSION  (-1)

#define Z_FILTERED            1
#define Z_HUFFMAN_ONLY        2
#define Z_DEFAULT_STRATEGY    0

#define Z_BINARY   0
#define Z_ASCII    1
#define Z_UNKNOWN  2

#define Z_DEFLATED   8

                        

extern int zlib_deflate_workspacesize (int windowBits, int memLevel);



extern int zlib_deflate (z_streamp strm, int flush);


extern int zlib_deflateEnd (z_streamp strm);


extern int zlib_inflate_workspacesize (void);



extern int zlib_inflate (z_streamp strm, int flush);
/*
    inflate decompresses as much data as possible, and stops when the input
  buffer becomes empty or the output buffer becomes full. It may introduce
  some output latency (reading input without producing any output) except when
  forced to flush.

  The detailed semantics are as follows. inflate performs one or both of the
  following actions:

  - Decompress more input starting at next_in and update next_in and avail_in
    accordingly. If not all input can be processed (because there is not
    enough room in the output buffer), next_in is updated and processing
    will resume at this point for the next call of inflate().

  - Provide more output starting at next_out and update next_out and avail_out
    accordingly.  inflate() provides as much output as possible, until there
    is no more input data or no more space in the output buffer (see below
    about the flush parameter).

  Before the call of inflate(), the application should ensure that at least
  one of the actions is possible, by providing more input and/or consuming
  more output, and updating the next_* and avail_* values accordingly.
  The application can consume the uncompressed output when it wants, for
  example when the output buffer is full (avail_out == 0), or after each
  call of inflate(). If inflate returns Z_OK and with zero avail_out, it
  must be called again after making room in the output buffer because there
  might be more output pending.

    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
  Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
  output as possible to the output buffer. Z_BLOCK requests that inflate() stop
  if and when it gets to the next deflate block boundary. When decoding the
  zlib or gzip format, this will cause inflate() to return immediately after
  the header and before the first block. When doing a raw inflate, inflate()
  will go ahead and process the first block, and will return when it gets to
  the end of that block, or when it runs out of data.

    The Z_BLOCK option assists in appending to or combining deflate streams.
  Also to assist in this, on return inflate() will set strm->data_type to the
  number of unused bits in the last byte taken from strm->next_in, plus 64
  if inflate() is currently decoding the last block in the deflate stream,
  plus 128 if inflate() returned immediately after decoding an end-of-block
  code or decoding the complete header up to just before the first byte of the
  deflate stream. The end-of-block will not be indicated until all of the
  uncompressed data from that block has been written to strm->next_out.  The
  number of unused bits may in general be greater than seven, except when
  bit 7 of data_type is set, in which case the number of unused bits will be
  less than eight.

    inflate() should normally be called until it returns Z_STREAM_END or an
  error. However if all decompression is to be performed in a single step
  (a single call of inflate), the parameter flush should be set to
  Z_FINISH. In this case all pending input is processed and all pending
  output is flushed; avail_out must be large enough to hold all the
  uncompressed data. (The size of the uncompressed data may have been saved
  by the compressor for this purpose.) The next operation on this stream must
  be inflateEnd to deallocate the decompression state. The use of Z_FINISH
  is never required, but can be used to inform inflate that a faster approach
  may be used for the single inflate() call.

     In this implementation, inflate() always flushes as much output as
  possible to the output buffer, and always uses the faster approach on the
  first call. So the only effect of the flush parameter in this implementation
  is on the return value of inflate(), as noted below, or when it returns early
  because Z_BLOCK is used.

     If a preset dictionary is needed after this call (see inflateSetDictionary
  below), inflate sets strm->adler to the adler32 checksum of the dictionary
  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
  strm->adler to the adler32 checksum of all output produced so far (that is,
  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
  below. At the end of the stream, inflate() checks that its computed adler32
  checksum is equal to that saved by the compressor and returns Z_STREAM_END
  only if the checksum is correct.

    inflate() will decompress and check either zlib-wrapped or gzip-wrapped
  deflate data.  The header type is detected automatically.  Any information
  contained in the gzip header is not retained, so applications that need that
  information should instead use raw inflate, see inflateInit2() below, or
  inflateBack() and perform their own processing of the gzip header and
  trailer.

    inflate() returns Z_OK if some progress has been made (more input processed
  or more output produced), Z_STREAM_END if the end of the compressed data has
  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
  corrupted (input stream not conforming to the zlib format or incorrect check
  value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
  if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
  Z_BUF_ERROR if no progress is possible or if there was not enough room in the
  output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
  inflate() can be called again with more input and more output space to
  continue decompressing. If Z_DATA_ERROR is returned, the application may then
  call inflateSync() to look for a good compression block if a partial recovery
  of the data is desired.
*/


extern int zlib_inflateEnd (z_streamp strm);

                        


                            
#if 0
extern int zlib_deflateSetDictionary (z_streamp strm,
						     const Byte *dictionary,
						     uInt  dictLength);
#endif

#if 0
extern int zlib_deflateCopy (z_streamp dest, z_streamp source);
#endif


extern int zlib_deflateReset (z_streamp strm);

static inline unsigned long deflateBound(unsigned long s)
{
	return s + ((s + 7) >> 3) + ((s + 63) >> 6) + 11;
}

#if 0
extern int zlib_deflateParams (z_streamp strm, int level, int strategy);
#endif


extern int zlib_inflateSetDictionary (z_streamp strm,
						     const Byte *dictionary,
						     uInt  dictLength);

#if 0
extern int zlib_inflateSync (z_streamp strm);
#endif

extern int zlib_inflateReset (z_streamp strm);

extern int zlib_inflateIncomp (z_stream *strm);

#define zlib_deflateInit(strm, level) \
	zlib_deflateInit2((strm), (level), Z_DEFLATED, MAX_WBITS, \
			      DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY)
#define zlib_inflateInit(strm) \
	zlib_inflateInit2((strm), DEF_WBITS)

extern int zlib_deflateInit2(z_streamp strm, int  level, int  method,
                                      int windowBits, int memLevel,
                                      int strategy);
extern int zlib_inflateInit2(z_streamp strm, int  windowBits);

#if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL)
    struct internal_state {int dummy;}; 
#endif

extern int zlib_inflate_blob(void *dst, unsigned dst_sz, const void *src, unsigned src_sz);

#endif