org.sf.xrime.algorithms.BC.Pajek2LabeledAdjBiSetVertexTransformer.java Source code

Introduction

Here is the source code for org.sf.xrime.algorithms.BC.Pajek2LabeledAdjBiSetVertexTransformer.java

Source

/*
 * Copyright (C) yangcheng@BUPT. 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.BC;

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

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
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.Reducer;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.SequenceFileOutputFormat;

import org.sf.xrime.ProcessorExecutionException;
import org.sf.xrime.Transformer;
import org.sf.xrime.model.vertex.LabeledAdjBiSetVertex;
import org.sf.xrime.model.edge.AdjVertexEdge;

/**
 * @author Yang Cheng
 * the function is to transform  the input format from Pajek to the format we need in 
 * BC Algorithm
 * the input's format: there exists two kinds of input
 * V: indicates this is a vertex
 * e: indicates this is an undirected edge
 * 
 * the output's format:
 * (key, value)
 * key is the Text
 * value is the LabeledAdjBiSetVertex whose id is key
 *  
 * 
 * 
 */
public class Pajek2LabeledAdjBiSetVertexTransformer extends Transformer {
    /** Default constructor.*/
    public Pajek2LabeledAdjBiSetVertexTransformer() {
        super();
    }

    /**
     * Normal constructor.
     * @param src
     * @param dest
     */
    public Pajek2LabeledAdjBiSetVertexTransformer(String src, String dest) {
        super(new Path(src), new Path(dest));
    }

    public Pajek2LabeledAdjBiSetVertexTransformer(Path src, Path dest) {
        super(src, dest);
    }

    public static class MapClass extends MapReduceBase implements Mapper<LongWritable, Text, Text, Text> {

        Text vertsource = new Text();
        Text vertdest = new Text();

        public void map(LongWritable key, Text value, OutputCollector<Text, Text> output, Reporter reporter)
                throws IOException {
            String line = value.toString().trim();
            String[] input = line.split(" ");
            String kind = input[0]; //get the kind of input, vertex, arch, or edge,indicated by the first letter
            String source, dest;
            if (kind.equals("v")) // just simple vertex
            {
                source = input[1];
                vertsource.set(source);
                vertdest.set("dest");
                output.collect(vertsource, vertdest);
            }

            if (kind.equals("e")) //an  undirected edge
            {
                source = input[1];
                dest = input[2];
                vertsource.set(source);
                vertdest.set(dest);
                output.collect(vertsource, vertdest);
                output.collect(vertdest, vertsource);
            }
        }
    }

    public static class ReduceClass extends MapReduceBase
            implements Reducer<Text, Text, Text, LabeledAdjBiSetVertex> {

        LabeledAdjBiSetVertex vertex = new LabeledAdjBiSetVertex();

        public void reduce(Text key, Iterator<Text> values, OutputCollector<Text, LabeledAdjBiSetVertex> output,
                Reporter reporter) throws IOException {

            vertex.setId(key.toString());
            AdjVertexEdge edge = new AdjVertexEdge();
            LabeledAdjBiSetVertex vertex = new LabeledAdjBiSetVertex();
            vertex.setId(key.toString());
            String opposite;
            while (values.hasNext()) {
                opposite = values.next().toString();
                if (opposite.equals("dest")) //means the input is a vertex and ignore this information
                {
                    continue;
                }
                edge.setOpposite(opposite);

                vertex.addBackwardVertex((AdjVertexEdge) edge.clone());
                vertex.addForwardVertex((AdjVertexEdge) edge.clone());
            }
            BCLabel label = (BCLabel) vertex.getLabel(BCLabel.bcLabelPathsKey);
            if (label == null) {
                label = new BCLabel();
                label.setBC(0);
                label.setDistance(-1);
                label.setNumber(0);
                vertex.setLabel(BCLabel.bcLabelPathsKey, label);
            }

            output.collect(key, vertex);
        }
    }

    public void execute() throws ProcessorExecutionException {
        JobConf jobConf = new JobConf(conf, Pajek2LabeledAdjBiSetVertexTransformer.class);
        jobConf.setJobName("tansfer_pajek2LabeledAdjBiSetvert");

        jobConf.setMapperClass(MapClass.class);
        jobConf.setReducerClass(ReduceClass.class);
        jobConf.setOutputFormat(SequenceFileOutputFormat.class);
        jobConf.setMapOutputKeyClass(Text.class);
        jobConf.setMapOutputValueClass(Text.class);
        jobConf.setOutputKeyClass(Text.class);
        jobConf.setOutputValueClass(LabeledAdjBiSetVertex.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);
        }
    }
}