/* 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; | |
} |