@Override
public void compute(
Vertex<IntWritable, IntWritable, NullWritable> vertex, Iterable<IntWritable> messages)
throws IOException {
if (0 == getSuperstep()) {
vertex.setValue(new IntWritable(Integer.MAX_VALUE));
}
Integer minDist = isSource(vertex) ? 0 : Integer.MAX_VALUE;
for (IntWritable msg : messages) {
if (msg.get() < minDist) {
minDist = msg.get();
}
}
if (minDist < vertex.getValue().get()) {
vertex.setValue(new IntWritable(minDist));
for (Edge<IntWritable, NullWritable> edge : vertex.getEdges()) {
final IntWritable neighbor = edge.getTargetVertexId();
final Integer distance = minDist + 1;
sendMessage(neighbor, new IntWritable(distance));
}
}
vertex.voteToHalt();
}
@Override
public void compute(
Vertex<IntWritable, IntWritable, NullWritable> vertex, Iterable<IntWritable> messages)
throws IOException {
int currentLength = vertex.getValue().get();
// First superstep is special, because we can simply look at the neighbors
if (getSuperstep() == 0) {
if (isSource(vertex)) {
vertex.setValue(new IntWritable(0));
sendMessageToAllEdges(vertex, vertex.getValue());
} else {
vertex.setValue(new IntWritable(Integer.MAX_VALUE));
}
vertex.voteToHalt();
return;
}
boolean changed = false;
// did we get a smaller length ?
for (IntWritable message : messages) {
int candidateLength = message.get() + 1;
if (candidateLength < currentLength) {
currentLength = candidateLength;
changed = true;
}
}
// propagate new length to the neighbors
if (changed) {
vertex.setValue(new IntWritable(currentLength));
sendMessageToAllEdges(vertex, vertex.getValue());
}
vertex.voteToHalt();
}
// public static double level=0;
@Override
public void compute(
Vertex<LongWritable, DoubleWritable, FloatWritable> v, Iterable<DoubleWritable> msg)
throws IOException {
if (getSuperstep() == 0) {
if (isSource(v) == true) {
v.setValue(new DoubleWritable(0));
// level++;
sendMessageToAllEdges(v, new DoubleWritable(v.getId().get()));
} else v.setValue(new DoubleWritable(-1));
} else {
for (DoubleWritable messages : msg) {
if (v.getValue().get() == -1) {
v.setValue(messages);
for (Edge<LongWritable, FloatWritable> edge : v.getEdges()) {
if (edge.getTargetVertexId().get() != v.getValue().get()) {
sendMessage(edge.getTargetVertexId(), new DoubleWritable(v.getId().get()));
}
}
} else {
if (v.getValue().get() != messages.get()) {
removeEdgesRequest(v.getId(), new LongWritable((long) messages.get()));
removeEdgesRequest(new LongWritable((long) messages.get()), v.getId());
}
}
/*
if(v.getValue().get() > messages.get())
{
v.setValue(new DoubleWritable(getSuperstep()));
// changed=true;
}*/
}
if (v.getValue().get() == -1) {
for (Edge<LongWritable, FloatWritable> edge : v.getEdges()) {
if (edge.getTargetVertexId().get() != v.getValue().get())
sendMessage(edge.getTargetVertexId(), new DoubleWritable(v.getId().get()));
}
}
/* if(changed)
{
level++;
sendMessageToAllEdges(v,new DoubleWritable(level));
changed=false;
}*/
}
v.voteToHalt();
}
/**
* Propagates the smallest vertex id to all neighbors. Will always choose to halt and only
* reactivate if a smaller id has been sent to it.
*
* @param messages Iterator of messages from the previous superstep.
* @throws java.io.IOException
*/
@Override
public void compute(
Vertex<LongWritable, LongWritable, NullWritable> vertex, Iterable<LongWritable> messages)
throws IOException {
long currentComponent = vertex.getValue().get();
// First superstep is special, because we can simply look at the neighbors
if (getSuperstep() == 0) {
for (Edge<LongWritable, NullWritable> edge : vertex.getEdges()) {
long neighbor = edge.getTargetVertexId().get();
if (neighbor < currentComponent) {
currentComponent = neighbor;
}
}
// Only need to send value if it is not the own id
if (currentComponent != vertex.getValue().get()) {
vertex.setValue(new LongWritable(currentComponent));
for (Edge<LongWritable, NullWritable> edge : vertex.getEdges()) {
LongWritable neighbor = edge.getTargetVertexId();
if (neighbor.get() > currentComponent) {
sendMessage(neighbor, vertex.getValue());
}
}
}
vertex.voteToHalt();
return;
}
boolean changed = false;
// did we get a smaller id ?
for (LongWritable message : messages) {
long candidateComponent = message.get();
if (candidateComponent < currentComponent) {
currentComponent = candidateComponent;
changed = true;
}
}
// propagate new component id to the neighbors
if (changed) {
vertex.setValue(new LongWritable(currentComponent));
sendMessageToAllEdges(vertex, vertex.getValue());
}
vertex.voteToHalt();
}
@Override
public void compute(
Vertex<IntWritable, IntWritable, NullWritable> vertex, Iterable<IntWritable> messages)
throws IOException {
if (getSuperstep() == 0) {
// send list of this vertex's neighbors to all neighbors
for (Edge<IntWritable, NullWritable> edge : vertex.getEdges()) {
sendMessageToAllEdges(vertex, edge.getTargetVertexId());
}
} else {
for (IntWritable message : messages) {
// INTENTIONAL BUG: the original algorithm has these two lines, which
// avoids the
// NullPointerException, which the current code throws.
// final int current = (closeMap.get(message) == null) ?
// 0 : closeMap.get(message) + 1;
final int current = closeMap.get(message);
closeMap.put(message, current);
}
// make sure the result values are sorted and
// packaged in an IntArrayListWritable for output
Set<Pair> sortedResults = Sets.<Pair>newTreeSet();
for (Map.Entry<IntWritable, Integer> entry : closeMap.entrySet()) {
sortedResults.add(new Pair(entry.getKey(), entry.getValue()));
}
IntArrayListWritable outputList = new IntArrayListWritable();
for (Pair pair : sortedResults) {
if (pair.value > 0) {
outputList.add(pair.key);
} else {
break;
}
}
if (outputList.isEmpty()) {
vertex.setValue(new IntWritable(-1));
} else {
vertex.setValue(outputList.get(0));
}
}
vertex.voteToHalt();
}
