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_ABSTRACT_NODE_LOOKUP_TASK_H 36 #define D_DHT_ABSTRACT_NODE_LOOKUP_TASK_H 37 38 #include "DHTAbstractTask.h" 39 40 #include <cstring> 41 #include <algorithm> 42 #include <deque> 43 #include <vector> 44 45 #include "DHTConstants.h" 46 #include "DHTNodeLookupEntry.h" 47 #include "DHTRoutingTable.h" 48 #include "DHTMessageDispatcher.h" 49 #include "DHTMessageFactory.h" 50 #include "DHTMessage.h" 51 #include "DHTNode.h" 52 #include "DHTBucket.h" 53 #include "LogFactory.h" 54 #include "Logger.h" 55 #include "util.h" 56 #include "DHTIDCloser.h" 57 #include "a2functional.h" 58 #include "fmt.h" 59 60 namespace aria2 { 61 62 class DHTNode; 63 class DHTMessage; 64 65 template <class ResponseMessage> 66 class DHTAbstractNodeLookupTask : public DHTAbstractTask { 67 private: 68 unsigned char targetID_[DHT_ID_LENGTH]; 69 70 std::deque<std::unique_ptr<DHTNodeLookupEntry>> entries_; 71 72 size_t inFlightMessage_; 73 74 template <typename Container> toEntries(Container & entries,const std::vector<std::shared_ptr<DHTNode>> & nodes)75 void toEntries(Container& entries, 76 const std::vector<std::shared_ptr<DHTNode>>& nodes) const 77 { 78 for (auto& node : nodes) { 79 entries.push_back(make_unique<DHTNodeLookupEntry>(node)); 80 } 81 } 82 sendMessage()83 void sendMessage() 84 { 85 for (auto i = std::begin(entries_), eoi = std::end(entries_); 86 i != eoi && inFlightMessage_ < ALPHA; ++i) { 87 if ((*i)->used == false) { 88 ++inFlightMessage_; 89 (*i)->used = true; 90 getMessageDispatcher()->addMessageToQueue(createMessage((*i)->node), 91 createCallback()); 92 } 93 } 94 } 95 sendMessageAndCheckFinish()96 void sendMessageAndCheckFinish() 97 { 98 if (needsAdditionalOutgoingMessage()) { 99 sendMessage(); 100 } 101 if (inFlightMessage_ == 0) { 102 A2_LOG_DEBUG(fmt("Finished node_lookup for node ID %s", 103 util::toHex(targetID_, DHT_ID_LENGTH).c_str())); 104 onFinish(); 105 updateBucket(); 106 setFinished(true); 107 } 108 else { 109 A2_LOG_DEBUG(fmt("%lu in flight message for node ID %s", 110 static_cast<unsigned long>(inFlightMessage_), 111 util::toHex(targetID_, DHT_ID_LENGTH).c_str())); 112 } 113 } 114 updateBucket()115 void updateBucket() {} 116 117 protected: getTargetID()118 const unsigned char* getTargetID() const { return targetID_; } 119 getEntries()120 const std::deque<std::unique_ptr<DHTNodeLookupEntry>>& getEntries() const 121 { 122 return entries_; 123 } 124 125 virtual void getNodesFromMessage(std::vector<std::shared_ptr<DHTNode>>& nodes, 126 const ResponseMessage* message) = 0; 127 onReceivedInternal(const ResponseMessage * message)128 virtual void onReceivedInternal(const ResponseMessage* message) {} 129 needsAdditionalOutgoingMessage()130 virtual bool needsAdditionalOutgoingMessage() { return true; } 131 onFinish()132 virtual void onFinish() {} 133 134 virtual std::unique_ptr<DHTMessage> 135 createMessage(const std::shared_ptr<DHTNode>& remoteNode) = 0; 136 137 virtual std::unique_ptr<DHTMessageCallback> createCallback() = 0; 138 139 public: DHTAbstractNodeLookupTask(const unsigned char * targetID)140 DHTAbstractNodeLookupTask(const unsigned char* targetID) : inFlightMessage_(0) 141 { 142 memcpy(targetID_, targetID, DHT_ID_LENGTH); 143 } 144 145 static const size_t ALPHA = 3; 146 startup()147 virtual void startup() CXX11_OVERRIDE 148 { 149 std::vector<std::shared_ptr<DHTNode>> nodes; 150 getRoutingTable()->getClosestKNodes(nodes, targetID_); 151 entries_.clear(); 152 toEntries(entries_, nodes); 153 if (entries_.empty()) { 154 setFinished(true); 155 } 156 else { 157 // TODO use RTT here 158 inFlightMessage_ = 0; 159 sendMessage(); 160 if (inFlightMessage_ == 0) { 161 A2_LOG_DEBUG("No message was sent in this lookup stage. Finished."); 162 setFinished(true); 163 } 164 } 165 } 166 onReceived(const ResponseMessage * message)167 void onReceived(const ResponseMessage* message) 168 { 169 --inFlightMessage_; 170 // Replace old Node ID with new Node ID. 171 for (auto& entry : entries_) { 172 if (entry->node->getIPAddress() == 173 message->getRemoteNode()->getIPAddress() && 174 entry->node->getPort() == message->getRemoteNode()->getPort()) { 175 entry->node = message->getRemoteNode(); 176 } 177 } 178 onReceivedInternal(message); 179 std::vector<std::shared_ptr<DHTNode>> nodes; 180 getNodesFromMessage(nodes, message); 181 std::vector<std::unique_ptr<DHTNodeLookupEntry>> newEntries; 182 toEntries(newEntries, nodes); 183 184 size_t count = 0; 185 for (auto& ne : newEntries) { 186 if (memcmp(getLocalNode()->getID(), ne->node->getID(), DHT_ID_LENGTH) != 187 0) { 188 A2_LOG_DEBUG(fmt("Received nodes: id=%s, ip=%s", 189 util::toHex(ne->node->getID(), DHT_ID_LENGTH).c_str(), 190 ne->node->getIPAddress().c_str())); 191 entries_.push_front(std::move(ne)); 192 ++count; 193 } 194 } 195 A2_LOG_DEBUG(fmt("%lu node lookup entries added.", 196 static_cast<unsigned long>(count))); 197 std::stable_sort(std::begin(entries_), std::end(entries_), 198 DHTIDCloser(targetID_)); 199 entries_.erase( 200 std::unique(std::begin(entries_), std::end(entries_), 201 DerefEqualTo<std::unique_ptr<DHTNodeLookupEntry>>{}), 202 std::end(entries_)); 203 A2_LOG_DEBUG(fmt("%lu node lookup entries are unique.", 204 static_cast<unsigned long>(entries_.size()))); 205 if (entries_.size() > DHTBucket::K) { 206 entries_.erase(std::begin(entries_) + DHTBucket::K, std::end(entries_)); 207 } 208 sendMessageAndCheckFinish(); 209 } 210 onTimeout(const std::shared_ptr<DHTNode> & node)211 void onTimeout(const std::shared_ptr<DHTNode>& node) 212 { 213 A2_LOG_DEBUG(fmt("node lookup message timeout for node ID=%s", 214 util::toHex(node->getID(), DHT_ID_LENGTH).c_str())); 215 --inFlightMessage_; 216 for (auto i = std::begin(entries_), eoi = std::end(entries_); i != eoi; 217 ++i) { 218 if (*(*i)->node == *node) { 219 entries_.erase(i); 220 break; 221 } 222 } 223 sendMessageAndCheckFinish(); 224 } 225 }; 226 227 } // namespace aria2 228 229 #endif // D_DHT_ABSTRACT_NODE_LOOKUP_TASK_H 230