public BenchPerformance(String fileName, Graph graph) {
r = Runtime.getRuntime();
forceGC();
long used1 = r.totalMemory() - r.freeMemory();
g = graph;
try {
g.read(fileName);
} catch (Exception e) {
e.printStackTrace();
System.exit(0);
}
System.out.println(
"Graph read: " + g.getNodeCount() + " nodes and " + g.getEdgeCount() + " edges");
for (Node n : g) n.clearAttributes();
for (Edge e : g.getEachEdge()) e.clearAttributes();
forceGC();
long used2 = r.totalMemory() - r.freeMemory();
measureValues = new EnumMap<Measures, Long>(Measures.class);
measureValues.put(Measures.MEMORY, used2 - used1);
nodeIds = new ArrayList<String>(g.getNodeCount());
for (Node n : g) nodeIds.add(n.getId());
// sort them to be sure that we always work with the same nodes
Collections.sort(nodeIds);
edgeIds = new ArrayList<String>(g.getEdgeCount());
for (Edge e : g.getEachEdge()) edgeIds.add(e.getId());
Collections.sort(edgeIds);
}
SynchronizedGraph(Graph g) {
super(g);
elementLock = new ReentrantLock();
synchronizedNodes = new HashMap<String, Node>();
synchronizedEdges = new HashMap<String, Edge>();
for (Node n : g.getEachNode())
synchronizedNodes.put(n.getId(), new SynchronizedNode(this, n));
for (Edge e : g.getEachEdge())
synchronizedEdges.put(e.getId(), new SynchronizedEdge(this, e));
}
/*
* (non-Javadoc)
*
* @see org.graphstream.algorithm.Algorithm#compute()
*/
@SuppressWarnings("unchecked")
public void compute() {
Node source = graph.getNode(this.source_id);
// Step 1: Initialize graph
for (Node n : graph) {
if (n == source) n.addAttribute(identifier + ".distance", 0.0);
else n.addAttribute(identifier + ".distance", Double.POSITIVE_INFINITY);
// n.addAttribute(identifier+".predecessors",(Object)null);
}
// Step 2: relax edges repeatedly
for (int i = 0; i < graph.getNodeCount(); i++) {
for (Edge e : graph.getEachEdge()) {
Node n0 = e.getNode0();
Node n1 = e.getNode1();
Double d0 = (Double) n0.getAttribute(identifier + ".distance");
Double d1 = (Double) n1.getAttribute(identifier + ".distance");
Double we = (Double) e.getAttribute(weightAttribute);
if (we == null)
throw new NumberFormatException(
"org.graphstream.algorithm.BellmanFord: Problem with attribute \""
+ weightAttribute
+ "\" on edge "
+ e);
if (d0 != null) {
if (d1 == null || d1 >= d0 + we) {
n1.addAttribute(identifier + ".distance", d0 + we);
ArrayList<Edge> predecessors =
(ArrayList<Edge>) n1.getAttribute(identifier + ".predecessors");
if (d1 != null && d1 == d0 + we) {
if (predecessors == null) {
predecessors = new ArrayList<Edge>();
}
} else {
predecessors = new ArrayList<Edge>();
}
if (!predecessors.contains(e)) {
predecessors.add(e);
}
n1.addAttribute(identifier + ".predecessors", predecessors);
}
}
}
}
// Step 3: check for negative-weight cycles
for (Edge e : graph.getEachEdge()) {
Node n0 = e.getNode0();
Node n1 = e.getNode1();
Double d0 = (Double) n0.getAttribute(identifier + ".distance");
Double d1 = (Double) n1.getAttribute(identifier + ".distance");
Double we = (Double) e.getAttribute(weightAttribute);
if (we == null) {
throw new NumberFormatException(
String.format(
"%s: Problem with attribute \"%s\" on edge \"%s\"",
BellmanFord.class.getName(), weightAttribute, e.getId()));
}
if (d1 > d0 + we) {
throw new NumberFormatException(
String.format(
"%s: Problem: negative weight, cycle detected on edge \"%s\"",
BellmanFord.class.getName(), e.getId()));
}
}
}
