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.ByteArrayInputStream; 033import java.io.DataInputStream; 034import java.io.IOException; 035import org.apache.hadoop.io.BytesWritable; 036import org.apache.hadoop.io.RawComparator; 037 038 039/** 040 * Read a tokenpair and make sure the single words appear before the pair words 041 * @author Sina Samangooei (ss@ecs.soton.ac.uk) 042 * 043 */ 044public class PMISortValueGroupingComparator implements RawComparator<BytesWritable> { 045 046 @Override 047 public int compare(BytesWritable o1, BytesWritable o2) { 048 return compareData(o1.getBytes(),0,o1.getLength(),o2.getBytes(),0,o2.getLength()); 049 } 050 051 @Override 052 public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) { 053 return compareData(b1,s1+4,l1-4,b2,s2+4,l2-4); 054 } 055 056 private int compareData(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) { 057 DataInputStream dis1 = new DataInputStream(new ByteArrayInputStream(b1,s1,l1)); 058 DataInputStream dis2 = new DataInputStream(new ByteArrayInputStream(b2,s2,l2)); 059 060 try { 061 // group up by times first 062 long t1; 063 long t2; 064 t1 = dis1.readLong(); 065 t2 = dis2.readLong(); 066 067 if(t1 < t2){ 068 return -1; 069 } 070 else if(t1 > t2){ 071 return 1; 072 } 073 return 0; 074 } catch (IOException e) { 075 } 076 return 0; 077 } 078}