aria2/src/SinkStreamFilter.cc

105 lines
3.7 KiB
C++

/* <!-- copyright */
/*
* aria2 - The high speed download utility
*
* Copyright (C) 2010 Tatsuhiro Tsujikawa
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of portions of this program with the
* OpenSSL library under certain conditions as described in each
* individual source file, and distribute linked combinations
* including the two.
* You must obey the GNU General Public License in all respects
* for all of the code used other than OpenSSL. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you
* do not wish to do so, delete this exception statement from your
* version. If you delete this exception statement from all source
* files in the program, then also delete it here.
*/
/* copyright --> */
#include "SinkStreamFilter.h"
#include <cstring>
#include <cassert>
#include "BinaryStream.h"
#include "Segment.h"
#include "WrDiskCache.h"
#include "Piece.h"
namespace aria2 {
const std::string SinkStreamFilter::NAME("SinkStreamFilter");
SinkStreamFilter::SinkStreamFilter(WrDiskCache* wrDiskCache, bool hashUpdate):
wrDiskCache_(wrDiskCache),
hashUpdate_(hashUpdate),
bytesProcessed_(0) {}
ssize_t SinkStreamFilter::transform
(const std::shared_ptr<BinaryStream>& out,
const std::shared_ptr<Segment>& segment,
const unsigned char* inbuf, size_t inlen)
{
size_t wlen;
if(inlen > 0) {
if(segment->getLength() > 0) {
// We must not write data larger than available space in
// segment.
assert(segment->getLength() >= segment->getWrittenLength());
size_t lenAvail = segment->getLength()-segment->getWrittenLength();
wlen = std::min(inlen, lenAvail);
} else {
wlen = inlen;
}
const std::shared_ptr<Piece>& piece = segment->getPiece();
if(piece->getWrDiskCacheEntry()) {
assert(wrDiskCache_);
// If we receive small data (e.g., 1 or 2 bytes), cache entry
// becomes a headache. To mitigate this problem, we allocate
// cache buffer at least 4KiB and append the data to the
// contagious cache data.
size_t alen = piece->appendWrCache(wrDiskCache_,
segment->getPositionToWrite(),
inbuf, wlen);
if(alen < wlen) {
size_t len = wlen - alen;
size_t capacity = std::max(len, static_cast<size_t>(4096));
auto dataCopy = new unsigned char[capacity];
memcpy(dataCopy, inbuf + alen, len);
piece->updateWrCache(wrDiskCache_, dataCopy, 0, len, capacity,
segment->getPositionToWrite() + alen);
}
} else {
out->writeData(inbuf, wlen, segment->getPositionToWrite());
}
#ifdef ENABLE_MESSAGE_DIGEST
if(hashUpdate_) {
segment->updateHash(segment->getWrittenLength(), inbuf, wlen);
}
#endif // ENABLE_MESSAGE_DIGEST
segment->updateWrittenLength(wlen);
} else {
wlen = 0;
}
bytesProcessed_ = wlen;
return bytesProcessed_;
}
} // namespace aria2