edu.isi.mavuno.extract.CombineGlobalStats.java Source code

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Here is the source code for edu.isi.mavuno.extract.CombineGlobalStats.java

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/*
 * Mavuno: A Hadoop-Based Text Mining Toolkit
 * 
 * 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 edu.isi.mavuno.extract;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.log4j.Logger;

import edu.isi.mavuno.util.ContextPatternStatsWritable;
import edu.isi.mavuno.util.ContextPatternWritable;
import edu.isi.mavuno.util.MavunoUtils;

/**
 * @author metzler
 *
 */
public class CombineGlobalStats extends Configured implements Tool {
    private static final Logger sLogger = Logger.getLogger(CombineGlobalStats.class);

    public CombineGlobalStats(Configuration conf) {
        super(conf);
    }

    private static class MyMapper extends
            Mapper<ContextPatternWritable, ContextPatternStatsWritable, ContextPatternWritable, ContextPatternStatsWritable> {
        /* identity mapper */
    }

    private static class MyReducer extends
            Reducer<ContextPatternWritable, ContextPatternStatsWritable, ContextPatternWritable, ContextPatternStatsWritable> {

        private final ContextPatternStatsWritable mCountScorePair = new ContextPatternStatsWritable();

        @Override
        public void reduce(ContextPatternWritable key, Iterable<ContextPatternStatsWritable> values,
                Reducer<ContextPatternWritable, ContextPatternStatsWritable, ContextPatternWritable, ContextPatternStatsWritable>.Context context)
                throws IOException, InterruptedException {
            mCountScorePair.zero();

            for (ContextPatternStatsWritable p : values) {
                mCountScorePair.increment(p);
            }

            context.write(key, mCountScorePair);
        }

    }

    /* (non-Javadoc)
     * @see org.apache.hadoop.util.Tool#run(java.lang.String[])
     */
    @Override
    public int run(String[] args) throws ClassNotFoundException, InterruptedException, IOException {
        MavunoUtils.readParameters(args, "Mavuno.CombineGlobalStats", getConf());
        return run();
    }

    public int run() throws ClassNotFoundException, InterruptedException, IOException {
        Configuration conf = getConf();

        String inputPath = MavunoUtils.getRequiredParam("Mavuno.CombineGlobalStats.InputPath", conf);
        String outputPath = MavunoUtils.getRequiredParam("Mavuno.CombineGlobalStats.OutputPath", conf);
        int numSplits = conf.getInt("Mavuno.CombineGlobalStats.TotalSplits", 1);

        sLogger.info("Tool name: CombineGlobalStats");
        sLogger.info(" - Input path: " + inputPath);
        sLogger.info(" - Output path: " + outputPath);
        sLogger.info(" - Number of splits: " + numSplits);

        Job job = new Job(conf);
        job.setJobName("CombineGlobalStats");

        for (int split = 0; split < numSplits; split++) {
            FileInputFormat.addInputPath(job, new Path(inputPath + "/" + split));
        }
        FileOutputFormat.setOutputPath(job, new Path(outputPath));

        job.setInputFormatClass(SequenceFileInputFormat.class);
        job.setOutputFormatClass(SequenceFileOutputFormat.class);

        FileOutputFormat.setCompressOutput(job, true);
        SequenceFileOutputFormat.setOutputCompressionType(job, SequenceFile.CompressionType.BLOCK);

        job.setMapOutputKeyClass(ContextPatternWritable.class);
        job.setSortComparatorClass(ContextPatternWritable.Comparator.class);
        job.setMapOutputValueClass(ContextPatternStatsWritable.class);

        job.setOutputKeyClass(ContextPatternWritable.class);
        job.setOutputValueClass(ContextPatternStatsWritable.class);

        job.setMapperClass(MyMapper.class);
        job.setCombinerClass(MyReducer.class);
        job.setReducerClass(MyReducer.class);

        job.waitForCompletion(true);

        return 0;
    }

}