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.outputmode.timeseries;
031
032import java.io.StringWriter;
033import org.apache.hadoop.io.BytesWritable;
034import org.apache.hadoop.io.NullWritable;
035import org.apache.hadoop.io.Text;
036import org.apache.hadoop.mapreduce.Reducer;
037import org.openimaj.hadoop.tools.twitter.utils.WordDFIDF;
038import org.openimaj.hadoop.tools.twitter.utils.WordDFIDFTimeSeries;
039import org.openimaj.io.IOUtils;
040
041/**
042 * Given a stream of wordDFIDF as input, reads each DFIDF, constructs a time series and emits the time series
043 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
044 *
045 */
046public class WordDFIDFTimeSeriesReducer extends Reducer<Text, BytesWritable, NullWritable, Text> {
047        @Override
048        protected void reduce(Text word, java.lang.Iterable<BytesWritable> dfidfs, Reducer<Text,BytesWritable,NullWritable,Text>.Context context) throws java.io.IOException ,InterruptedException {
049                WordDFIDFTimeSeries dts = new WordDFIDFTimeSeries();
050                for (BytesWritable bytesWritable : dfidfs) {
051                        WordDFIDF wd = IOUtils.deserialize(bytesWritable.getBytes(), WordDFIDF.class);
052                        dts.add(wd.timeperiod, wd);
053                }
054                StringWriter writer = new StringWriter();
055                writer.write(word + " ");
056                IOUtils.writeASCII(writer, dts);
057                context.write(NullWritable.get(), new Text(writer .toString()));
058        };
059}