1 /* <!-- copyright */ 2 /* 3 * aria2 - The high speed download utility 4 * 5 * Copyright (C) 2006 Tatsuhiro Tsujikawa 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 * 21 * In addition, as a special exception, the copyright holders give 22 * permission to link the code of portions of this program with the 23 * OpenSSL library under certain conditions as described in each 24 * individual source file, and distribute linked combinations 25 * including the two. 26 * You must obey the GNU General Public License in all respects 27 * for all of the code used other than OpenSSL. If you modify 28 * file(s) with this exception, you may extend this exception to your 29 * version of the file(s), but you are not obligated to do so. If you 30 * do not wish to do so, delete this exception statement from your 31 * version. If you delete this exception statement from all source 32 * files in the program, then also delete it here. 33 */ 34 /* copyright --> */ 35 #ifndef D_DHT_BUCKET_H 36 #define D_DHT_BUCKET_H 37 38 #include "common.h" 39 40 #include <string> 41 #include <deque> 42 #include <vector> 43 #include <memory> 44 45 #include "DHTConstants.h" 46 #include "TimerA2.h" 47 48 namespace aria2 { 49 50 class DHTNode; 51 52 class DHTBucket { 53 private: 54 size_t prefixLength_; 55 56 // this bucket contains nodes of distance between [min_, max_](inclusive). 57 unsigned char min_[DHT_ID_LENGTH]; 58 59 unsigned char max_[DHT_ID_LENGTH]; 60 61 std::shared_ptr<DHTNode> localNode_; 62 63 // sorted in ascending order 64 std::deque<std::shared_ptr<DHTNode>> nodes_; 65 66 // a replacement cache. The maximum size is specified by CACHE_SIZE. 67 // This is sorted by last time seen. 68 std::deque<std::shared_ptr<DHTNode>> cachedNodes_; 69 70 Timer lastUpdated_; 71 72 bool isInRange(const unsigned char* nodeID, const unsigned char* max, 73 const unsigned char* min) const; 74 75 public: 76 DHTBucket(const std::shared_ptr<DHTNode>& localNode); 77 78 DHTBucket(size_t prefixLength, const unsigned char* max, 79 const unsigned char* min, 80 const std::shared_ptr<DHTNode>& localNode); 81 82 ~DHTBucket(); 83 84 static const size_t K = 8; 85 86 static const size_t CACHE_SIZE = 2; 87 88 void getRandomNodeID(unsigned char* nodeID) const; 89 90 std::unique_ptr<DHTBucket> split(); 91 92 bool isInRange(const std::shared_ptr<DHTNode>& node) const; 93 94 bool isInRange(const unsigned char* nodeID) const; 95 96 bool addNode(const std::shared_ptr<DHTNode>& node); 97 98 void cacheNode(const std::shared_ptr<DHTNode>& node); 99 100 bool splitAllowed() const; 101 getPrefixLength()102 size_t getPrefixLength() const { return prefixLength_; } 103 getMaxID()104 const unsigned char* getMaxID() const { return max_; } 105 getMinID()106 const unsigned char* getMinID() const { return min_; } 107 countNode()108 size_t countNode() const { return nodes_.size(); } 109 getNodes()110 const std::deque<std::shared_ptr<DHTNode>>& getNodes() const 111 { 112 return nodes_; 113 } 114 115 void getGoodNodes(std::vector<std::shared_ptr<DHTNode>>& nodes) const; 116 117 void dropNode(const std::shared_ptr<DHTNode>& node); 118 119 void moveToHead(const std::shared_ptr<DHTNode>& node); 120 121 void moveToTail(const std::shared_ptr<DHTNode>& node); 122 123 bool contains(const std::shared_ptr<DHTNode>& node) const; 124 125 std::shared_ptr<DHTNode> getNode(const unsigned char* nodeID, 126 const std::string& ipaddr, 127 uint16_t port) const; 128 129 bool operator==(const DHTBucket& bucket) const; 130 131 bool needsRefresh() const; 132 133 void notifyUpdate(); 134 135 bool containsQuestionableNode() const; 136 137 std::shared_ptr<DHTNode> getLRUQuestionableNode() const; 138 getCachedNodes()139 const std::deque<std::shared_ptr<DHTNode>>& getCachedNodes() const 140 { 141 return cachedNodes_; 142 } 143 }; 144 145 } // namespace aria2 146 147 #endif // D_DHT_BUCKET_H 148