001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.hadoop.tools;
031
032import java.util.ArrayList;
033import java.util.Arrays;
034import java.util.List;
035
036import org.apache.hadoop.conf.Configured;
037import org.apache.hadoop.fs.Path;
038import org.apache.hadoop.mapreduce.Job;
039import org.apache.hadoop.mapreduce.Mapper;
040import org.apache.hadoop.mapreduce.Reducer;
041import org.apache.hadoop.util.Tool;
042import org.apache.hadoop.util.ToolRunner;
043import org.kohsuke.args4j.CmdLineException;
044import org.kohsuke.args4j.CmdLineParser;
045import org.kohsuke.args4j.Option;
046import org.openimaj.hadoop.mapreduce.TextBytesJobUtil;
047
048/**
049 * Map-Reduce based tool that merges sequence files
050 * 
051 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
052 * 
053 */
054public class SequenceFileMerger extends Configured implements Tool {
055        @Option(name = "--input", aliases = "-i", usage = "input paths or uris", multiValued = true, required = true)
056        private List<String> inputs;
057
058        @Option(name = "--output", aliases = "-o", usage = "output path", required = true)
059        private String output;
060
061        @Option(name = "--num-outputs", aliases = "-n", usage = "number of outputs", required = true)
062        private int numOutputs;
063
064        /**
065         * Runs the tool
066         * 
067         * @param args
068         * @throws Exception
069         */
070        public static void main(String[] args) throws Exception {
071                ToolRunner.run(new SequenceFileMerger(), args);
072        }
073
074        @Override
075        public int run(String[] args) throws Exception {
076                final CmdLineParser parser = new CmdLineParser(this);
077
078                try {
079                        parser.parseArgument(args);
080                } catch (final CmdLineException e) {
081                        System.err.println(e.getMessage());
082                        System.err.println("Usage: hadoop jar SequenceFileMerger.jar [options...]");
083                        parser.printUsage(System.err);
084                        return 1;
085                }
086
087                final List<Path> allPaths = new ArrayList<Path>();
088                for (final String p : inputs) {
089                        allPaths.addAll(Arrays.asList(HadoopToolsUtil.getInputPaths(p)));
090                }
091
092                final Job job = TextBytesJobUtil.createJob(allPaths, new Path(output), null, this.getConf());
093                job.setJarByClass(this.getClass());
094                job.setMapperClass(Mapper.class);
095                job.setReducerClass(Reducer.class);
096                job.setNumReduceTasks(this.numOutputs);
097
098                job.waitForCompletion(true);
099
100                return 0;
101        }
102}