edu.umd.cloud9.collection.trecweb.RepackGov2Documents.java Source code

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Here is the source code for edu.umd.cloud9.collection.trecweb.RepackGov2Documents.java

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/*
 * Cloud9: A MapReduce Library for Hadoop
 * 
 * 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.umd.cloud9.collection.trecweb;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.mapred.FileInputFormat;
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.Reporter;
import org.apache.hadoop.mapred.SequenceFileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;

/**
 * <p>
 * Program to uncompress the gov2 collection from the original distribution and
 * repack as <code>SequenceFiles</code>.
 * </p>
 * 
 * <p>
 * The program takes three command-line arguments:
 * </p>
 * 
 * <ul>
 * <li>[base-path] base path of the ClueWeb09 distribution</li>
 * <li>[output-path] output path</li>
 * <li>(block|record|none) to indicate block-compression, record-compression,
 * or no compression</li>
 * </ul>
 * 
 * @author Jimmy Lin
 * 
 */
@SuppressWarnings("deprecation")
public class RepackGov2Documents extends Configured implements Tool {

    private static final Logger sLogger = Logger.getLogger(RepackGov2Documents.class);

    private static enum Documents {
        Count
    };

    private static class MyMapper extends MapReduceBase
            implements Mapper<LongWritable, TrecWebDocument, LongWritable, TrecWebDocument> {
        public void map(LongWritable key, TrecWebDocument doc,
                OutputCollector<LongWritable, TrecWebDocument> output, Reporter reporter) throws IOException {
            reporter.incrCounter(Documents.Count, 1);

            // sLogger.info("============" + doc.getDocid() + "============" +
            // doc.getContent());

            output.collect(key, doc);
        }
    }

    private RepackGov2Documents() {
    }

    private static int printUsage() {
        System.out.println("usage: [base-path] [output-path] (block|record|none)");
        ToolRunner.printGenericCommandUsage(System.out);
        return -1;
    }

    /**
     * Runs this tool.
     */
    public int run(String[] args) throws Exception {
        if (args.length != 3) {
            printUsage();
            return -1;
        }

        String basePath = args[0];
        String outputPath = args[1];
        String compressionType = args[2];

        if (!compressionType.equals("block") && !compressionType.equals("record")
                && !compressionType.equals("none")) {
            System.err.println("Error: \"" + compressionType + "\" unknown compression type!");
            System.exit(-1);
        }

        // this is the default block size
        int blocksize = 1000000;

        JobConf conf = new JobConf(RepackGov2Documents.class);
        conf.setJobName("RepackGov2Documents");

        sLogger.info("Tool name: RepackGov2Documents");
        sLogger.info(" - base path: " + basePath);
        sLogger.info(" - output path: " + outputPath);
        sLogger.info(" - compression type: " + compressionType);

        if (compressionType.equals("block")) {
            sLogger.info(" - block size: " + blocksize);
        }

        int mapTasks = 10;

        conf.setNumMapTasks(mapTasks);
        conf.setNumReduceTasks(500);

        // 272
        for (int i = 0; i <= 272; i++) {
            String path = basePath + "/GX";
            String indexNum = Integer.toString(i);
            if (indexNum.length() == 1) {
                path += "00";
            }
            if (indexNum.length() == 2) {
                path += "0";
            }
            path += indexNum;
            FileInputFormat.addInputPath(conf, new Path(path));
        }

        SequenceFileOutputFormat.setOutputPath(conf, new Path(outputPath));

        if (compressionType.equals("none")) {
            SequenceFileOutputFormat.setCompressOutput(conf, false);
        } else {
            SequenceFileOutputFormat.setCompressOutput(conf, true);

            if (compressionType.equals("record")) {
                SequenceFileOutputFormat.setOutputCompressionType(conf, SequenceFile.CompressionType.RECORD);
            } else {
                SequenceFileOutputFormat.setOutputCompressionType(conf, SequenceFile.CompressionType.BLOCK);
                conf.setInt("io.seqfile.compress.blocksize", blocksize);
            }
        }

        conf.setInputFormat(TrecWebDocumentInputFormat.class);
        conf.setOutputFormat(SequenceFileOutputFormat.class);
        conf.setOutputKeyClass(LongWritable.class);
        conf.setOutputValueClass(TrecWebDocument.class);

        conf.setMapperClass(MyMapper.class);

        // delete the output directory if it exists already
        FileSystem.get(conf).delete(new Path(outputPath), true);

        JobClient.runJob(conf);

        return 0;
    }

    /**
     * Dispatches command-line arguments to the tool via the
     * <code>ToolRunner</code>.
     */
    public static void main(String[] args) throws Exception {
        int res = ToolRunner.run(new Configuration(), new RepackGov2Documents(), args);
        System.exit(res);
    }

}