+++ /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.core.*;
-import peersim.config.Configuration;
-
-/**
- * This class provides a way to initialize a single node of the network.
- * The initialization is performed by choosing the bandwidth of the node
- * and choosing how much the shared file has been downloaded.
- */
-public class NodeInitializer{
-
- /**
- * The protocol to operate on.
- * @config
- */
- private static final String PAR_PROT="protocol";
-
- /**
- * The percentage of nodes with no downloaded pieces.
- * @config
- * @see "The documentation for an example on how to properly set this parameter."
- */
- private static final String PAR_NEWER_DISTR="newer_distr";
-
- /**
- * The percentage of seeders in the network.
- * @config
- */
- private static final String PAR_SEEDER_DISTR="seeder_distr";
-
- /**
- * The percentage of nodes with no downloaded pieces,
- * as defined in {@see #PAR_NEWER_DISTR}.
- */
- private int newerDistr;
-
- /**
- * The percentage of seeder nodes,
- * as defined in {@see #PAR_SEEDER_DISTR}.
- */
- private int seederDistr;
-
- /**
- * The BitTorrent protocol ID.
- */
- private final int pid;
-
- /**
- * The basic constructor of the class, which reads the parameters
- * from the configuration file.
- * @param prefix the configuration prefix for this class
- */
- public NodeInitializer(String prefix){
- pid = Configuration.getPid(prefix+"."+PAR_PROT);
- newerDistr = Configuration.getInt(prefix+"."+PAR_NEWER_DISTR);
- seederDistr = Configuration.getInt(prefix+"."+PAR_SEEDER_DISTR);
- }
-
- /**
- * Initializes the node <tt>n</tt> associating it
- * with the BitTorrent protocol and setting the reference to the tracker,
- * the status of the file and the bandwidth.
- * @param n The node to initialize
- */
- public void initialize(Node n){
- Node tracker = Network.get(0);
- BitTorrent p;
- p = (BitTorrent)n.getProtocol(pid);
- p.setTracker(tracker);
- p.setThisNodeID(n.getID());
- setFileStatus(p);
- setBandwidth(p);
- }
-
- /**
- * Sets the status of the shared file according to the
- * probability value given by {@link #getProbability()}.
- * @param p The BitTorrent protocol
- */
- private void setFileStatus(BitTorrent p){
- int percentage = getProbability();
- choosePieces(percentage, p);
- }
-
- /**
- * Set the maximum bandwidth for the node, choosing
- * uniformly at random among 4 values.
- * <p>
- * The allowed bandwidth speed are 640 Kbps, 1 Mbps, 2 Mbps and 4 Mbps.
- * </p>
- * @param p The BitTorrent protocol
- */
- private void setBandwidth(BitTorrent p){
- int value = CommonState.r.nextInt(4);
- switch(value){
- case 0: p.setBandwidth(640);break; //640Kbps
- case 1: p.setBandwidth(1024);break;// 1Mbps
- case 2: p.setBandwidth(2048);break;// 2Mbps
- case 3: p.setBandwidth(4096);break; //4Mbps
- }
- }
-
- /**
- * Sets the completed pieces for the given protocol <tt>p</tt>.
- * @parm percentage The percentage of the downloaded pieces, according to {@link #getProbability()}
- * @param p the BitTorrent protocol
- */
- private void choosePieces(int percentage, BitTorrent p){
- double temp = ((double)p.nPieces/100.0)*percentage; // We use a double to avoid the loss of precision
- // during the division operation
- int completed = (int)temp; //integer number of piece to set as completed
- //0 if the peer is a newer
- p.setCompleted(completed);
- if(percentage == 100)
- p.setPeerStatus(1);
- int tmp;
- while(completed!=0){
- tmp = CommonState.r.nextInt(p.nPieces);
- if(p.getStatus(tmp)!=16){
- p.setStatus(tmp, 16);
- completed--;
- }
- }
- }
-
- /**
- * Gets a probability according with the parameter <tt>newer_distr</tt>
- * defined in the configuration file.
- * @return the probabilty value, where 0 means that the peer is new and no pieces has been downloaded,
- * 100 means that the peer is a seeder; other values defines a random probability.
- * @see #PAR_NEWER_DISTR
- */
- private int getProbability(){
- int value = CommonState.r.nextInt(100);
- if((value+1)<=seederDistr)
- return 100;
- value = CommonState.r.nextInt(100);
- if((value+1)<=newerDistr){
- return 0; // A newer peer, with probability newer_distr
- }
- else{
- value = CommonState.r.nextInt(9);
- return (value+1)*10;
- }
- }
-}
\ No newline at end of file
