org.sf.xrime.algorithms.transform.vertex.OutAdjVertex2AdjSetVertexTransformer.java Source code

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Here is the source code for org.sf.xrime.algorithms.transform.vertex.OutAdjVertex2AdjSetVertexTransformer.java

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/*
 * Copyright (C) IBM Corp. 2009.
 * 
 * Licensed 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.sf.xrime.algorithms.transform.vertex;

import java.io.IOException;
import java.util.Iterator;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.compress.GzipCodec;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.SequenceFileInputFormat;
import org.apache.hadoop.mapred.SequenceFileOutputFormat;
import org.apache.hadoop.util.ToolRunner;
import org.sf.xrime.ProcessorExecutionException;
import org.sf.xrime.Transformer;
import org.sf.xrime.model.edge.AdjVertexEdge;
import org.sf.xrime.model.edge.Edge;
import org.sf.xrime.model.vertex.AdjSetVertex;
import org.sf.xrime.model.vertex.AdjVertex;

/**
 * Transform outgoing adjacency vertexes list into another form. The input should
 * be outgoing adjacency vertexes list. The output AdjSetVertex represents opposites
 * of all incident edges (both incoming and outgoing).
 * @author xue
 */
public class OutAdjVertex2AdjSetVertexTransformer extends Transformer {
    /**
     * Default constructor.
     */
    public OutAdjVertex2AdjSetVertexTransformer() {
        super();
    }

    /**
     * Another constructor.
     * @param src
     * @param dest
     */
    public OutAdjVertex2AdjSetVertexTransformer(Path src, Path dest) {
        super(src, dest);
    }

    /**
     * Transform outgoing adjacency vertexes lists to undirected ones.
     * @author xue
     */
    public static class MapClass extends MapReduceBase implements Mapper<Text, AdjVertex, Text, AdjSetVertex> {
        @Override
        public void map(Text key, AdjVertex value, OutputCollector<Text, AdjSetVertex> output, Reporter reporter)
                throws IOException {
            // The vertex "key" itself.
            AdjSetVertex out_vertex = new AdjSetVertex();
            // Don't forget this!!! 2009-05-10.
            out_vertex.fromAdjVertexTos(value);
            output.collect(key, out_vertex);
            // For each backward edge.
            for (Edge edge : value.getEdges()) {
                AdjSetVertex new_vertex = new AdjSetVertex();
                new_vertex.setId(edge.getTo());
                new_vertex.addOpposite(new AdjVertexEdge(value.getId()));
                output.collect(new Text(edge.getTo()), new_vertex);
            }
        }
    }

    /**
     * Continue to transform the outgoing adjacent vertexes list to undirected ones, and
     * set appropriate label each vertex.
     * @author xue
     */
    public static class ReduceClass extends MapReduceBase
            implements Reducer<Text, AdjSetVertex, Text, AdjSetVertex> {

        @Override
        public void reduce(Text key, Iterator<AdjSetVertex> values, OutputCollector<Text, AdjSetVertex> output,
                Reporter reporter) throws IOException {
            AdjSetVertex result_vertex = new AdjSetVertex();
            result_vertex.setId(key.toString());
            // Merge all adjacent vertexes into one set.
            while (values.hasNext()) {
                AdjSetVertex curr_set = values.next();
                for (AdjVertexEdge to : curr_set.getOpposites()) {
                    result_vertex.addOpposite(to);
                }
            }
            output.collect(key, result_vertex);
        }
    }

    @Override
    public void execute() throws ProcessorExecutionException {
        JobConf jobConf = new JobConf(conf, OutAdjVertex2AdjSetVertexTransformer.class);
        jobConf.setJobName("OutAdjVertex2AdjSetVertexTransformer");

        // the keys are vertex identifiers (strings)
        jobConf.setOutputKeyClass(Text.class);
        // the values are adjacent vertexes with labels (Writable)
        jobConf.setOutputValueClass(AdjSetVertex.class);
        jobConf.setMapperClass(MapClass.class);
        // no combiner is needed.
        jobConf.setReducerClass(ReduceClass.class);
        // makes the file format suitable for machine processing.
        jobConf.setInputFormat(SequenceFileInputFormat.class);
        jobConf.setOutputFormat(SequenceFileOutputFormat.class);
        // Enable compression.
        jobConf.setCompressMapOutput(true);
        jobConf.setMapOutputCompressorClass(GzipCodec.class);
        FileInputFormat.setInputPaths(jobConf, srcPath);
        FileOutputFormat.setOutputPath(jobConf, destPath);
        jobConf.setNumMapTasks(mapperNum);
        jobConf.setNumReduceTasks(reducerNum);

        try {
            this.runningJob = JobClient.runJob(jobConf);
        } catch (IOException e) {
            throw new ProcessorExecutionException(e);
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        try {
            int res = ToolRunner.run(new OutAdjVertex2AdjSetVertexTransformer(), args);
            System.exit(res);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}