aria2/src/OpenedFileCounter.cc

114 lines
3.3 KiB
C++

/* <!-- copyright */
/*
* aria2 - The high speed download utility
*
* Copyright (C) 2014 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 "OpenedFileCounter.h"
#include <cassert>
#include "RequestGroupMan.h"
#include "RequestGroup.h"
#include "PieceStorage.h"
#include "DiskAdaptor.h"
#include "SimpleRandomizer.h"
namespace aria2 {
OpenedFileCounter::OpenedFileCounter(RequestGroupMan* rgman,
size_t maxOpenFiles)
: rgman_(rgman), maxOpenFiles_(maxOpenFiles), numOpenFiles_(0)
{
}
void OpenedFileCounter::ensureMaxOpenFileLimit(size_t numNewFiles)
{
if (!rgman_) {
return;
}
if (numOpenFiles_ + numNewFiles <= maxOpenFiles_) {
numOpenFiles_ += numNewFiles;
return;
}
assert(numNewFiles <= maxOpenFiles_);
size_t numClose = numOpenFiles_ + numNewFiles - maxOpenFiles_;
size_t left = numClose;
auto& requestGroups = rgman_->getRequestGroups();
auto mark = std::begin(requestGroups);
std::advance(mark, SimpleRandomizer::getInstance()->getRandomNumber(
requestGroups.size()));
auto closeFun = [&left](const std::shared_ptr<RequestGroup>& group) {
auto& ps = group->getPieceStorage();
if (!ps) {
return;
}
auto diskAdaptor = ps->getDiskAdaptor();
if (!diskAdaptor) {
return;
}
left -= diskAdaptor->tryCloseFile(left);
};
for (auto i = mark; i != std::end(requestGroups) && left > 0; ++i) {
closeFun(*i);
}
for (auto i = std::begin(requestGroups); i != mark && left > 0; ++i) {
closeFun(*i);
}
assert(left == 0);
numOpenFiles_ += numNewFiles - numClose;
}
void OpenedFileCounter::reduceNumOfOpenedFile(size_t numCloseFiles)
{
if (!rgman_) {
return;
}
assert(numOpenFiles_ >= numCloseFiles);
numOpenFiles_ -= numCloseFiles;
}
void OpenedFileCounter::deactivate() { rgman_ = nullptr; }
} // namespace aria2