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/*
* Copyright (C) 2001-2008 Jacek Sieka, arnetheduck on gmail point com
*
* This program 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 program 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "stdinc.h"
#include "DCPlusPlus.h"
#include "ZUtils.h"
#include "Exception.h"
namespace dcpp {
const double ZFilter::MIN_COMPRESSION_LEVEL = 0.9;
ZFilter::ZFilter() : totalIn(0), totalOut(0), compressing(true) {
memset(&zs, 0, sizeof(zs));
if(deflateInit(&zs, 3) != Z_OK) {
throw Exception(_("Error during compression"));
}
}
ZFilter::~ZFilter() {
dcdebug("ZFilter end, %ld/%ld = %.04f\n", zs.total_out, zs.total_in, (float)zs.total_out / max((float)zs.total_in, (float)1));
deflateEnd(&zs);
}
bool ZFilter::operator()(const void* in, size_t& insize, void* out, size_t& outsize) {
if(outsize == 0)
return false;
zs.next_in = (Bytef*)in;
zs.next_out = (Bytef*)out;
// Check if there's any use compressing; if not, save some cpu...
if(compressing && insize > 0 && outsize > 16 && (totalIn > (64*1024)) && ((static_cast<double>(totalOut) / totalIn) > 0.95)) {
zs.avail_in = 0;
zs.avail_out = outsize;
if(deflateParams(&zs, 0, Z_DEFAULT_STRATEGY) != Z_OK) {
throw Exception(_("Error during compression"));
}
zs.avail_in = insize;
compressing = false;
dcdebug("Dynamically disabled compression");
// Check if we ate all space already...
if(zs.avail_out == 0) {
outsize = outsize - zs.avail_out;
insize = insize - zs.avail_in;
totalOut += outsize;
totalIn += insize;
return true;
}
} else {
zs.avail_in = insize;
zs.avail_out = outsize;
}
if(insize == 0) {
int err = ::deflate(&zs, Z_FINISH);
if(err != Z_OK && err != Z_STREAM_END)
throw Exception(_("Error during compression"));
outsize = outsize - zs.avail_out;
insize = insize - zs.avail_in;
totalOut += outsize;
totalIn += insize;
return err == Z_OK;
} else {
int err = ::deflate(&zs, Z_NO_FLUSH);
if(err != Z_OK)
throw Exception(_("Error during compression"));
outsize = outsize - zs.avail_out;
insize = insize - zs.avail_in;
totalOut += outsize;
totalIn += insize;
return true;
}
}
UnZFilter::UnZFilter() {
memset(&zs, 0, sizeof(zs));
if(inflateInit(&zs) != Z_OK)
throw Exception(_("Error during decompression"));
}
UnZFilter::~UnZFilter() {
dcdebug("UnZFilter end, %ld/%ld = %.04f\n", zs.total_out, zs.total_in, (float)zs.total_out / max((float)zs.total_in, (float)1));
inflateEnd(&zs);
}
bool UnZFilter::operator()(const void* in, size_t& insize, void* out, size_t& outsize) {
if(outsize == 0)
return 0;
zs.avail_in = insize;
zs.next_in = (Bytef*)in;
zs.avail_out = outsize;
zs.next_out = (Bytef*)out;
int err = ::inflate(&zs, Z_NO_FLUSH);
// see zlib/contrib/minizip/unzip.c, Z_BUF_ERROR means we should have padded
// with a dummy byte if at end of stream - since we don't do this it's not a real
// error
if(!(err == Z_OK || err == Z_STREAM_END || (err == Z_BUF_ERROR && in == NULL)))
throw Exception(_("Error during decompression"));
outsize = outsize - zs.avail_out;
insize = insize - zs.avail_in;
return err == Z_OK;
}
} // namespace dcpp
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