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/***************************************************************************
* *
* copyright (C) 2003, 2004 by Michael Buesch *
* email: mbuesch@freenet.de *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License version 2 *
* as published by the Free Software Foundation. *
* *
***************************************************************************/
/***************************************************************************
* copyright (C) 2004 by Ulf Schenk
* This file is originaly based on version 1.0.1 of pwmanager
* and was modified to run on embedded devices that run microkde
*
* $Id$
**************************************************************************/
#include "compressgzip.h"
#include <stdlib.h>
#include <zlib.h>
#define COMPRESSION_LEVEL Z_BEST_COMPRESSION
#define EXPAND_COMPRESS_DESTBUF_BYTES 1024
#define EXPAND_DECOMPRESS_DESTBUF_BYTES (1024 * 10)
bool CompressGzip::compress(string *d)
{
int ret;
Bytef *dest;
const Bytef *source;
unsigned long sourceLen, destLen;
source = reinterpret_cast<const Bytef *>(d->c_str());
sourceLen = d->length();
destLen = calcCompressDestLen(sourceLen);
dest = static_cast<Bytef *>(malloc(destLen));
if (!dest)
return false;
while (1) {
ret = compress2(dest,
static_cast<uLongf *>(&destLen),
source,
static_cast<uLong>(sourceLen),
COMPRESSION_LEVEL);
switch (ret) {
case Z_OK:
goto out;
case Z_BUF_ERROR:
/* we don't use realloc(), because it may
* (in this case) unneccessarily copy the old block
* to the new allocated block.
*/
free(dest);
destLen += EXPAND_COMPRESS_DESTBUF_BYTES;
dest = static_cast<Bytef *>(malloc(destLen));
if (!dest)
return false;
break;
default:
free(dest);
return false;
}
}
out:
d->assign(reinterpret_cast<char *>(dest), destLen);
free(dest);
return true;
}
bool CompressGzip::decompress(string *d)
{
int ret;
Bytef *dest;
const Bytef *source;
unsigned long sourceLen, destLen;
source = reinterpret_cast<const Bytef *>(d->c_str());
sourceLen = d->length();
destLen = calcDecompressDestLen(sourceLen);
dest = static_cast<Bytef *>(malloc(destLen));
if (!dest)
return false;
while (1) {
ret = uncompress(dest,
static_cast<uLongf *>(&destLen),
source,
static_cast<uLong>(sourceLen));
switch (ret) {
case Z_OK:
goto out;
case Z_BUF_ERROR:
/* we don't use realloc(), because it may
* (in this case) unneccessarily copy the old block
* to the new allocated block.
*/
free(dest);
destLen += EXPAND_DECOMPRESS_DESTBUF_BYTES;
dest = static_cast<Bytef *>(malloc(destLen));
if (!dest)
return false;
break;
default:
free(dest);
return false;
}
}
out:
d->assign(reinterpret_cast<char *>(dest), destLen);
free(dest);
return true;
}
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