aria2/src/DHTBucket.h

148 lines
4.0 KiB
C++

/* <!-- copyright */
/*
* aria2 - The high speed download utility
*
* Copyright (C) 2006 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 --> */
#ifndef _D_DHT_BUCKET_H_
#define _D_DHT_BUCKET_H_
#include "common.h"
#include "SharedHandle.h"
#include "DHTConstants.h"
#include "TimeA2.h"
#include <string>
#include <deque>
namespace aria2 {
class DHTNode;
class Logger;
class DHTBucket {
private:
size_t _prefixLength;
// this bucket contains nodes of distance between [_min, _max](inclusive).
unsigned char _min[DHT_ID_LENGTH];
unsigned char _max[DHT_ID_LENGTH];
SharedHandle<DHTNode> _localNode;
// sorted in ascending order
std::deque<SharedHandle<DHTNode> > _nodes;
// a replacement cache. The maximum size is specified by CACHE_SIZE.
// This is sorted by last time seen.
std::deque<SharedHandle<DHTNode> > _cachedNodes;
Time _lastUpdated;
Logger* _logger;
bool isInRange(const unsigned char* nodeID,
const unsigned char* max, const unsigned char* min) const;
public:
DHTBucket(const SharedHandle<DHTNode>& localNode);
DHTBucket(size_t prefixLength,
const unsigned char* max, const unsigned char* min,
const SharedHandle<DHTNode>& localNode);
~DHTBucket();
static const size_t K = 8;
static const size_t CACHE_SIZE = 2;
void getRandomNodeID(unsigned char* nodeID) const;
SharedHandle<DHTBucket> split();
bool isInRange(const SharedHandle<DHTNode>& node) const;
bool isInRange(const unsigned char* nodeID) const;
bool addNode(const SharedHandle<DHTNode>& node);
void cacheNode(const SharedHandle<DHTNode>& node);
bool splitAllowed() const;
size_t getPrefixLength() const
{
return _prefixLength;
}
const unsigned char* getMaxID() const
{
return _max;
}
const unsigned char* getMinID() const
{
return _min;
}
size_t countNode() const;
const std::deque<SharedHandle<DHTNode> >& getNodes() const;
void getGoodNodes(std::deque<SharedHandle<DHTNode> >& nodes) const;
void dropNode(const SharedHandle<DHTNode>& node);
void moveToHead(const SharedHandle<DHTNode>& node);
void moveToTail(const SharedHandle<DHTNode>& node);
bool contains(const SharedHandle<DHTNode>& node) const;
SharedHandle<DHTNode> getNode(const unsigned char* nodeID, const std::string& ipaddr, uint16_t port) const;
bool operator==(const DHTBucket& bucket) const;
bool needsRefresh() const;
void notifyUpdate();
bool containsQuestionableNode() const;
SharedHandle<DHTNode> getLRUQuestionableNode() const;
const std::deque<SharedHandle<DHTNode> >& getCachedNodes() const;
};
} // namespace aria2
#endif // _D_DHT_BUCKET_H_