/*
* Title: CloudSim Toolkit
* Description: CloudSim (Cloud Simulation) Toolkit for Modeling and Simulation of Clouds
* Licence: GPL - http://www.gnu.org/copyleft/gpl.html
*
* Copyright (c) 2009-2012, The University of Melbourne, Australia
*/
package org.cloudbus.cloudsim.network;
import java.util.Iterator;
/**
* This class represents a delay matrix between every pair or nodes
* inside a network topology, storing every distance between connected nodes.
*
* @author Thomas Hohnstein
* @since CloudSim Toolkit 1.0
*/
public class DelayMatrix_Float {
/**
* Matrix holding delay information between any two nodes.
*/
protected float[][] mDelayMatrix = null;
/**
* Number of nodes in the distance-aware-topology.
*/
protected int mTotalNodeNum = 0;
/**
* Private constructor to ensure that only an correct initialized delay-matrix could be created.
*/
@SuppressWarnings("unused")
private DelayMatrix_Float() {
}
/**
* Creates an correctly initialized Float-Delay-Matrix.
*
* @param graph the network topological graph
* @param directed indicates if an directed matrix should be computed (true) or not (false)
*/
public DelayMatrix_Float(TopologicalGraph graph, boolean directed) {
// lets preinitialize the Delay-Matrix
createDelayMatrix(graph, directed);
// now its time to calculate all possible connection-delays
calculateShortestPath();
}
/**
* Gets the delay between two nodes.
*
* @param srcID the id of the source node
* @param destID the id of the destination node
* @return the delay between the given two nodes
*/
public float getDelay(int srcID, int destID) {
// check the nodeIDs against internal array-boundarys
if (srcID > mTotalNodeNum || destID > mTotalNodeNum) {
throw new ArrayIndexOutOfBoundsException("srcID or destID is higher than highest stored node-ID!");
}
return mDelayMatrix[srcID][destID];
}
/**
* Creates all internal necessary network-distance structures from the given graph.
* For similarity, we assume all communication-distances are symmetrical,
* thus leading to an undirected network.
*
* @param graph the network topological graph
* @param directed indicates if an directed matrix should be computed (true) or not (false)
*/
private void createDelayMatrix(TopologicalGraph graph, boolean directed) {
// number of nodes inside the network
mTotalNodeNum = graph.getNumberOfNodes();
mDelayMatrix = new float[mTotalNodeNum][mTotalNodeNum];
// cleanup the complete distance-matrix with "0"s
for (int row = 0; row < mTotalNodeNum; ++row) {
for (int col = 0; col < mTotalNodeNum; ++col) {
mDelayMatrix[row][col] = Float.MAX_VALUE;
}
}
Iterator<TopologicalLink> itr = graph.getLinkIterator();
TopologicalLink edge;
while (itr.hasNext()) {
edge = itr.next();
mDelayMatrix[edge.getSrcNodeID()][edge.getDestNodeID()] = edge.getLinkDelay();
if (!directed) {
// according to aproximity of symmetry to all communication-paths
mDelayMatrix[edge.getDestNodeID()][edge.getSrcNodeID()] = edge.getLinkDelay();
}
}
}
/**
* Calculates the shortest path between all pairs of nodes.
*/
private void calculateShortestPath() {
FloydWarshall_Float floyd = new FloydWarshall_Float();
floyd.initialize(mTotalNodeNum);
mDelayMatrix = floyd.allPairsShortestPaths(mDelayMatrix);
}
@Override
public String toString() {
StringBuffer buffer = new StringBuffer();
buffer.append("just a simple printout of the distance-aware-topology-class\n");
buffer.append("delay-matrix is:\n");
for (int column = 0; column < mTotalNodeNum; ++column) {
buffer.append("\t" + column);
}
for (int row = 0; row < mTotalNodeNum; ++row) {
buffer.append("\n" + row);
for (int col = 0; col < mTotalNodeNum; ++col) {
if (mDelayMatrix[row][col] == Float.MAX_VALUE) {
buffer.append("\t" + "-");
} else {
buffer.append("\t" + mDelayMatrix[row][col]);
}
}
}
return buffer.toString();
}
}