--- /dev/null
+/*
+ * Copyright (c) 2007-2008 Fabrizio Frioli, Michele Pedrolli
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * --
+ *
+ * Please send your questions/suggestions to:
+ * {fabrizio.frioli, michele.pedrolli} at studenti dot unitn dot it
+ *
+ */
+
+package example.bittorrent;
+
+import peersim.config.*;
+import peersim.core.*;
+import peersim.util.*;
+
+/**
+ * This {@link Control} provides a way to keep track of some
+ * parameters of the BitTorrent network.
+ */
+ public class BTObserver implements Control {
+
+ /**
+ * The protocol to operate on.
+ * @config
+ */
+ private static final String PAR_PROT="protocol";
+
+ /**
+ * Protocol identifier, obtained from config property
+ */
+ private final int pid;
+
+ /**
+ * The basic constructor that reads the configuration file.
+ * @param prefix the configuration prefix for this class
+ */
+ public BTObserver(String prefix) {
+ pid = Configuration.getPid(prefix + "." + PAR_PROT);
+ }
+
+ /**
+ * Prints information about the BitTorrent network
+ * and the number of leechers and seeders.
+ * Please refer to the code comments for more details.
+ * @return always false
+ */
+ public boolean execute() {
+ IncrementalFreq nodeStatusStats = new IncrementalFreq();
+ IncrementalStats neighborStats = new IncrementalStats();
+
+ int numberOfNodes = Network.size();
+ int numberOfCompletedPieces = 0;
+
+ // cycles from 1, since the node 0 is the tracker
+ for (int i=1; i<numberOfNodes; ++i) {
+
+ // stats on number of leechers and seeders in the network
+ // and consequently also on number of completed files in the network
+ nodeStatusStats.add(((BitTorrent)(Network.get(i).getProtocol(pid))).getPeerStatus());
+
+ // stats on number of neighbors per peer
+ neighborStats.add(((BitTorrent)(Network.get(i).getProtocol(pid))).getNNodes());
+ }
+
+ // number of the pieces of the file, equal for every node, here 1 is chosen,
+ // since 1 is the first "normal" node (0 is the tracker)
+ int numberOfPieces = ((BitTorrent)(Network.get(1).getProtocol(pid))).nPieces;
+
+ for (int i=1; i<numberOfNodes; ++i) {
+ numberOfCompletedPieces = 0;
+
+ // discovers the status of the current peer (leecher or seeder)
+ int ps = ((BitTorrent)(Network.get(i).getProtocol(pid))).getPeerStatus();
+ String peerStatus;
+ if (ps==0) {
+ peerStatus = "L"; //leecher
+ }
+ else {
+ peerStatus = "S"; //seeder
+ }
+
+
+ if (Network.get(i)!=null) {
+
+ // counts the number of completed pieces for the i-th node
+ for (int j=0; j<numberOfPieces; j++) {
+ if ( ((BitTorrent)(Network.get(i).getProtocol(pid))).getFileStatus()[j] == 16) {
+ numberOfCompletedPieces++;
+ }
+ }
+
+ /*
+ * Put here the output lines of the Observer. An example is provided with
+ * basic information and stats.
+ * CommonState.getTime() is used to print out time references
+ * (useful for graph plotting).
+ */
+
+ System.out.println("OBS: node " + ((BitTorrent)(Network.get(i).getProtocol(pid))).getThisNodeID() + "(" + peerStatus + ")" + "\t pieces completed: " + numberOfCompletedPieces + "\t \t down: " + ((BitTorrent)(Network.get(i).getProtocol(pid))).nPiecesDown + "\t up: " + ((BitTorrent)(Network.get(i).getProtocol(pid))).nPiecesUp + " time: " + CommonState.getTime());
+ //System.out.println("[OBS] t " + CommonState.getTime() + "\t pc " + numberOfCompletedPieces + "\t n " + ((BitTorrent)(Network.get(i).getProtocol(pid))).getThisNodeID());
+ //System.out.println( CommonState.getTime() + "\t" + numberOfCompletedPieces + "\t" + ((BitTorrent)(Network.get(i).getProtocol(pid))).getThisNodeID());
+
+ }
+ else {
+ //System.out.println("[OBS] t " + CommonState.getTime() + "\t pc " + "0" + "\t n " + "0");
+ }
+
+ }
+
+ // prints the frequency of 0 (leechers) and 1 (seeders)
+ nodeStatusStats.printAll(System.out);
+
+ // prints the average number of neighbors per peer
+ System.out.println("Avg number of neighbors per peer: " + neighborStats.getAverage());
+
+ return false;
+ }
+}
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