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/*
* This file is part of the SPL: Solaris Porting Layer.
*
* Copyright (c) 2008 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory
* Written by:
* Brian Behlendorf <behlendorf1@llnl.gov>,
* Herb Wartens <wartens2@llnl.gov>,
* Jim Garlick <garlick@llnl.gov>
* UCRL-CODE-235197
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef _SPL_ZMOD_H
#define _SPL_ZMOD_H
#include <linux/zlib.h>
/* NOTE: z_compress_level/z_uncompress are nearly identical copies of
* the compress2/uncompress functions provided by the official zlib
* package available at http://zlib.net/. The only changes made we to
* slightly adapt the functioned called to match the linux kernel
* implementation of zlib.
*/
/* ===========================================================================
* Compresses the source buffer into the destination buffer. The level
* parameter has the same meaning as in deflateInit. sourceLen is the byte
* length of the source buffer. Upon entry, destLen is the total size of the
* destination buffer, which must be at least 0.1% larger than sourceLen plus
* 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
*
* compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
* memory, Z_BUF_ERROR if there was not enough room in the output buffer,
* Z_STREAM_ERROR if the level parameter is invalid.
*/
static __inline__ int
z_compress_level(Byte *dest, uLong *destLen, const Byte *source,
uLong sourceLen, int level)
{
z_stream stream;
int err;
stream.next_in = (Byte *)source;
stream.avail_in = (uInt)sourceLen;
#ifdef MAXSEG_64K
/* Check for source > 64K on 16-bit machine: */
if ((uLong)stream.avail_in != sourceLen)
return Z_BUF_ERROR;
#endif
stream.next_out = dest;
stream.avail_out = (uInt)*destLen;
if ((uLong)stream.avail_out != *destLen)
return Z_BUF_ERROR;
err = zlib_deflateInit(&stream, level);
if (err != Z_OK)
return err;
err = zlib_deflate(&stream, Z_FINISH);
if (err != Z_STREAM_END) {
zlib_deflateEnd(&stream);
return err == Z_OK ? Z_BUF_ERROR : err;
}
*destLen = stream.total_out;
err = zlib_deflateEnd(&stream);
return err;
} /* z_compress_level() */
/* ===========================================================================
* Decompresses the source buffer into the destination buffer. sourceLen is
* the byte length of the source buffer. Upon entry, destLen is the total
* size of the destination buffer, which must be large enough to hold the
* entire uncompressed data. (The size of the uncompressed data must have
* been saved previously by the compressor and transmitted to the decompressor
* by some mechanism outside the scope of this compression library.)
* Upon exit, destLen is the actual size of the compressed buffer.
* This function can be used to decompress a whole file at once if the
* input file is mmap'ed.
*
* uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
* enough memory, Z_BUF_ERROR if there was not enough room in the output
* buffer, or Z_DATA_ERROR if the input data was corrupted.
*/
static __inline__ int
z_uncompress(Byte *dest, uLong *destLen, const Byte *source, uLong sourceLen)
{
z_stream stream;
int err;
stream.next_in = (Byte *)source;
stream.avail_in = (uInt)sourceLen;
/* Check for source > 64K on 16-bit machine: */
if ((uLong)stream.avail_in != sourceLen)
return Z_BUF_ERROR;
stream.next_out = dest;
stream.avail_out = (uInt)*destLen;
if ((uLong)stream.avail_out != *destLen)
return Z_BUF_ERROR;
err = zlib_inflateInit(&stream);
if (err != Z_OK)
return err;
err = zlib_inflate(&stream, Z_FINISH);
if (err != Z_STREAM_END) {
zlib_inflateEnd(&stream);
if (err == Z_NEED_DICT ||
(err == Z_BUF_ERROR && stream.avail_in == 0))
return Z_DATA_ERROR;
return err;
}
*destLen = stream.total_out;
err = zlib_inflateEnd(&stream);
return err;
} /* z_uncompress() */
#endif /* SPL_ZMOD_H */
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