freebsd-skq/lib/libz/compress.c
Tim Kientzle 42307a8f43 Since the FreeBSD local modifications are mostly trivial (consisting
primarily of pointless $FreeBSD$ tags), sync most files in HEAD with
those in the ZLIB branch.  This minimizes the differences between
HEAD and ZLIB and should simplify future imports.

After this, there are only three files with local modifications
(gzio.c, minigzip.c, and zconf.h) and two non-vendor files
(Makefile, zopen.c).  The rest exactly match the vendor distribution.

PR:		i386/76294
MFC after:	2 weeks
2005-05-11 03:47:48 +00:00

80 lines
2.4 KiB
C

/* compress.c -- compress a memory buffer
* Copyright (C) 1995-2002 Jean-loup Gailly.
* For conditions of distribution and use, see copyright notice in zlib.h
*/
/* @(#) $Id$ */
#define ZLIB_INTERNAL
#include "zlib.h"
/* ===========================================================================
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.
*/
int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
Bytef *dest;
uLongf *destLen;
const Bytef *source;
uLong sourceLen;
int level;
{
z_stream stream;
int err;
stream.next_in = (Bytef*)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;
stream.zalloc = (alloc_func)0;
stream.zfree = (free_func)0;
stream.opaque = (voidpf)0;
err = deflateInit(&stream, level);
if (err != Z_OK) return err;
err = deflate(&stream, Z_FINISH);
if (err != Z_STREAM_END) {
deflateEnd(&stream);
return err == Z_OK ? Z_BUF_ERROR : err;
}
*destLen = stream.total_out;
err = deflateEnd(&stream);
return err;
}
/* ===========================================================================
*/
int ZEXPORT compress (dest, destLen, source, sourceLen)
Bytef *dest;
uLongf *destLen;
const Bytef *source;
uLong sourceLen;
{
return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
}
/* ===========================================================================
If the default memLevel or windowBits for deflateInit() is changed, then
this function needs to be updated.
*/
uLong ZEXPORT compressBound (sourceLen)
uLong sourceLen;
{
return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + 11;
}