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; 033import java.util.Map; 034 035import org.apache.hadoop.fs.Path; 036import org.apache.hadoop.io.BytesWritable; 037import org.apache.hadoop.mapreduce.Mapper; 038import org.openimaj.hadoop.tools.twitter.token.mode.pointwisemi.count.PairMutualInformation; 039import org.openimaj.hadoop.tools.twitter.token.mode.pointwisemi.count.TokenPairCount; 040import org.openimaj.hadoop.tools.twitter.token.mode.pointwisemi.count.TokenPairUnaryCount; 041import org.openimaj.io.IOUtils; 042 043/** 044 * @author Sina Samangooei (ss@ecs.soton.ac.uk) 045 * 046 */ 047public class PMISortMapper extends Mapper<BytesWritable, BytesWritable, BytesWritable, BytesWritable> { 048 private static double minp = -1; 049 private static int minPairCount; 050 private static Path pairmiloc; 051 private static Map<Long, Long> timecounts; 052 /** 053 * does nothing 054 */ 055 public PMISortMapper(){ 056 057 } 058 059 @Override 060 public void setup(Mapper<BytesWritable, BytesWritable,BytesWritable,BytesWritable>.Context context) throws IOException ,InterruptedException { 061 load(context); 062 }; 063 private synchronized static void load(Mapper<BytesWritable, BytesWritable,BytesWritable,BytesWritable>.Context context) throws IOException { 064 if(timecounts==null){ 065 minp = context.getConfiguration().getFloat(PMIPairSort.MINP_KEY, -1); 066 minPairCount = context.getConfiguration().getInt(PMIPairSort.MINPAIRCOUNT_KEY, 0); 067 pairmiloc = new Path(context.getConfiguration().get(PMIPairSort.PAIRMI_LOC)); 068 timecounts = PairMutualInformation.loadTimeCounts(pairmiloc); 069 } 070 } 071 072 @Override 073 public void map(BytesWritable key, BytesWritable value, Mapper<BytesWritable, BytesWritable,BytesWritable,BytesWritable>.Context context) throws IOException ,InterruptedException { 074 TokenPairUnaryCount tpuc = IOUtils.deserialize(value.getBytes(), TokenPairUnaryCount.class); 075 long timet = TokenPairCount.timeFromBinaryIdentity(key.getBytes()); 076 long n = timecounts.get(timet); 077 if( minPairCount != -1 && tpuc.paircount < minPairCount ) return; 078 double pmi = tpuc.pmi(n); 079 if(new Double(pmi).equals(Double.NaN)) return; 080 if( minp == -1 || pmi > minp){ 081 byte[] serialized = PMIPairSort.timePMIBinary(timet,pmi); 082 context.write(new BytesWritable(serialized), value); 083 } 084 }; 085}