| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.giraph.debugger.instrumenter.test.basecompute; |
| |
| import org.apache.giraph.conf.LongConfOption; |
| import org.apache.giraph.edge.Edge; |
| import org.apache.giraph.graph.BasicComputation; |
| import org.apache.giraph.graph.Vertex; |
| import org.apache.hadoop.io.DoubleWritable; |
| import org.apache.hadoop.io.FloatWritable; |
| import org.apache.hadoop.io.LongWritable; |
| import org.apache.log4j.Logger; |
| |
| /** |
| * TODO(semih, jaeho): What's this class used for? |
| */ |
| public class DerivedComputation extends BaseComputation { |
| |
| /** |
| * The shortest paths id. |
| */ |
| public static final LongConfOption SOURCE_ID = new LongConfOption( |
| "SimpleShortestPathsVertex.sourceId", 1, "The shortest paths id"); |
| |
| /** |
| * Class logger. |
| */ |
| private static final Logger LOG = Logger.getLogger(BasicComputation.class); |
| |
| /** |
| * Minimum distance found so far. Kept as a global variable for efficiency. |
| */ |
| private double minDist; |
| |
| @Override |
| protected void collect( |
| Vertex<LongWritable, DoubleWritable, FloatWritable> vertex, |
| Iterable<DoubleWritable> messages) { |
| if (getSuperstep() == 0) { |
| vertex.setValue(new DoubleWritable(Double.MAX_VALUE)); |
| } |
| if (getSuperstep() == 8) { |
| throw new RuntimeException("bug"); |
| } |
| minDist = isSource(vertex) ? 0d : Double.MAX_VALUE; |
| for (DoubleWritable message : messages) { |
| minDist = Math.min(minDist, message.get()); |
| } |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Vertex " + vertex.getId() + " got minDist = " + minDist + |
| " vertex value = " + vertex.getValue()); |
| } |
| } |
| |
| @Override |
| protected void signal( |
| Vertex<LongWritable, DoubleWritable, FloatWritable> vertex, |
| Iterable<DoubleWritable> messages) { |
| if (minDist < vertex.getValue().get()) { |
| vertex.setValue(new DoubleWritable(minDist)); |
| for (Edge<LongWritable, FloatWritable> edge : vertex.getEdges()) { |
| double distance = minDist + edge.getValue().get(); |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Vertex " + vertex.getId() + " sent to " + |
| edge.getTargetVertexId() + " = " + distance); |
| } |
| // INTENTIONAL BUG:Instead of sending the distance (i.e. by |
| // adding edge values), we send the vertex value. |
| sendMessage(edge.getTargetVertexId(), new DoubleWritable(minDist)); |
| } |
| } |
| } |
| |
| /** |
| * Is this vertex the source id? |
| * |
| * @param vertex |
| * Vertex |
| * @return True if the source id |
| */ |
| private boolean isSource(Vertex<LongWritable, ?, ?> vertex) { |
| return vertex.getId().get() == SOURCE_ID.get(getConf()); |
| } |
| } |