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.twitter.token.mode.pointwisemi.sort;
031
032import java.io.IOException;
033
034import org.apache.hadoop.conf.Configurable;
035import org.apache.hadoop.conf.Configuration;
036import org.apache.hadoop.io.BytesWritable;
037import org.apache.hadoop.mapreduce.Partitioner;
038import org.openimaj.hadoop.tools.twitter.token.mode.pointwisemi.count.PairMutualInformation;
039
040public class PMISortPartitioner extends Partitioner<BytesWritable,BytesWritable> implements Configurable {
041
042
043        private Configuration conf;
044        private Long timedelta;
045
046        @Override
047        public int getPartition(BytesWritable key, BytesWritable value, int numPartitions) {;
048                long time;
049                try {
050                        time = PMIPairSort.parseTimeBinary(key.getBytes()).firstObject();
051                        if(timedelta == -1) {
052                                return (int) (time % numPartitions);
053                        }
054                        else {
055                                return (int) ((time / timedelta) % numPartitions);
056                        }
057                } catch (IOException e) {
058                }
059                return 0;
060        }
061
062        @Override
063        public void setConf(Configuration conf) {
064                this.conf = conf;
065                this.timedelta = conf.getLong(PairMutualInformation.TIMEDELTA,-1);
066        }
067
068        @Override
069        public Configuration getConf() {
070                return conf;
071        }
072
073}