/* -*- tab-width: 4 -*-
*
* Electric(tm) VLSI Design System
*
* File: MSTMetric.java
* Written by Team 2: Jan Barth, Iskandar Abudiab
*
* This code has been developed at the Karlsruhe Institute of Technology (KIT), Germany,
* as part of the course "Multicore Programming in Practice: Tools, Models, and Languages".
* Contact instructor: Dr. Victor Pankratius (pankratius@ipd.uka.de)
*
* Copyright (c) 2010 Sun Microsystems and Static Free Software
*
* Electric(tm) is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* Electric(tm) 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Electric(tm); see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, Mass 02111-1307, USA.
*/
package com.sun.electric.tool.placement.simulatedAnnealing1.metrics;
import com.sun.electric.tool.placement.PlacementFrame.PlacementNetwork;
import com.sun.electric.tool.placement.PlacementFrame.PlacementNode;
import com.sun.electric.tool.placement.PlacementFrame.PlacementPort;
import com.sun.electric.tool.placement.simulatedAnnealing1.SimulatedAnnealing.IncrementalState;
import com.sun.electric.tool.placement.simulatedAnnealing1.SimulatedAnnealing.PlacementNodePosition;
import java.util.HashSet;
import java.util.List;
import java.util.TreeSet;
import java.util.Vector;
/** Parallel Placement
**/
public class MSTMetric extends AbstractMetric {
private IncrementalState incState;
private double currentScore;
@Override
public String getMetricName() { return "MSTMetric"; }
public MSTMetric(List<PlacementNode> nodesToPlace, List<PlacementNetwork> allNetworks, IncrementalState incState) {
super(nodesToPlace, allNetworks);
this.incState = incState;
}
public double init(List<PlacementNetwork> allNetworks) {
currentScore = compute();
return currentScore;
}
/**
* Get current score.
* @return current score, which is the estimated wire length.
*/
public double getCurrentScore() {
return currentScore;
}
public double update(int index) {
currentScore = compute();
return currentScore;
}
@Override
public double compute() {
double total = 0;
for(PlacementNetwork net : allNetworks) {
total += compute(net);
}
return total;
}
private double compute(PlacementNetwork net) {
//TreeSet is used to sort the edges before passing to the algorithm
TreeSet<Edge> edges = new TreeSet<Edge>();
for(PlacementPort port1 : net.getPortsOnNet()) {
for(PlacementPort port2 : net.getPortsOnNet()) {
edges.add(new Edge(port1.getPlacementNode().getType().getName(), port2.getPlacementNode().getType().getName(), getDistance(port1, port2)));
}
}
KruskalEdges vv = new KruskalEdges();
for (Edge edge : edges) {
vv.insertEdge(edge);
}
double total = 0;
for (Edge edge : vv.getEdges()) {
total += edge.getWeight();
}
return total;
}
private double getDistance(PlacementPort port1, PlacementPort port2) {
PlacementNodePosition n1 = incState.getNodeFromState(nodesToPlace.indexOf(port1.getPlacementNode()));
PlacementNodePosition n2 = incState.getNodeFromState(nodesToPlace.indexOf(port2.getPlacementNode()));
double deltaX = n1.getPlacementX() + port1.getRotatedOffX() - n2.getPlacementX() - port2.getOffX();
double deltaY = n1.getPlacementY() + port1.getRotatedOffY() - n2.getPlacementY() - port2.getOffY();
//return Math.sqrt((deltaX*deltaX) + (deltaY*deltaY));
return ((deltaX*deltaX) + (deltaY*deltaY));
}
// Quelle: http://www.krishami.com/programs/java/kruskal.aspx
/*
Kruskal's algorithm finds a minimum spanning tree for a connected weighted graph.
The program below uses a hard-coded example.
You can change this to match your problem by changing the edges in the graph.
The program uses 3 classes.
The Kruskal class contains the main method.
The Edge class represents an edge.
The KruskalEdges class contains the edges determined by the Kruskal algorithm.
*/
class Edge implements Comparable<Edge>
{
String vertexA, vertexB;
double weight;
public Edge(String vertexA, String vertexB, double weight)
{
this.vertexA = vertexA;
this.vertexB = vertexB;
this.weight = weight;
}
public String getVertexA()
{
return vertexA;
}
public String getVertexB()
{
return vertexB;
}
public double getWeight()
{
return weight;
}
@Override
public String toString()
{
return "(" + vertexA + ", " + vertexB + ") : Weight = " + weight;
}
public int compareTo(Edge edge)
{
//== is not compared so that duplicate values are not eliminated.
return (this.weight < edge.weight) ? -1: 1;
}
}
class KruskalEdges
{
Vector<HashSet<String>> vertexGroups = new Vector<HashSet<String>>();
TreeSet<Edge> kruskalEdges = new TreeSet<Edge>();
public TreeSet<Edge> getEdges()
{
return kruskalEdges;
}
HashSet<String> getVertexGroup(String vertex)
{
for (HashSet<String> vertexGroup : vertexGroups) {
if (vertexGroup.contains(vertex)) {
return vertexGroup;
}
}
return null;
}
/**
* The edge to be inserted has 2 vertices - A and B
* We maintain a vector that contains groups of vertices.
* We first check if either A or B exists in any group
* If neither A nor B exists in any group
* We create a new group containing both the vertices.
* If one of the vertices exists in a group and the other does not
* We add the vertex that does not exist to the group of the other vertex
* If both vertices exist in different groups
* We merge the two groups into one
* All of the above scenarios mean that the edge is a valid Kruskal edge
* In that scenario, we will add the edge to the Kruskal edges
* However, if both vertices exist in the same group
* We do not consider the edge as a valid Kruskal edge
*/
public void insertEdge(Edge edge)
{
String vertexA = edge.getVertexA();
String vertexB = edge.getVertexB();
HashSet<String> vertexGroupA = getVertexGroup(vertexA);
HashSet<String> vertexGroupB = getVertexGroup(vertexB);
if (vertexGroupA == null) {
kruskalEdges.add(edge);
if (vertexGroupB == null) {
HashSet<String> htNewVertexGroup = new HashSet<String>();
htNewVertexGroup.add(vertexA);
htNewVertexGroup.add(vertexB);
vertexGroups.add(htNewVertexGroup);
}
else {
vertexGroupB.add(vertexA);
}
}
else {
if (vertexGroupB == null) {
vertexGroupA.add(vertexB);
kruskalEdges.add(edge);
}
else if (vertexGroupA != vertexGroupB) {
vertexGroupA.addAll(vertexGroupB);
vertexGroups.remove(vertexGroupB);
kruskalEdges.add(edge);
}
}
}
}
}