    001/*
    002 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
    003 *
    004 * Project and contact information: http://www.cascading.org/
    005 *
    006 * This file is part of the Cascading project.
    007 *
    008 * Licensed under the Apache License, Version 2.0 (the "License");
    009 * you may not use this file except in compliance with the License.
    010 * You may obtain a copy of the License at
    011 *
    012 *     http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing, software
    015 * distributed under the License is distributed on an "AS IS" BASIS,
    016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    017 * See the License for the specific language governing permissions and
    018 * limitations under the License.
    019 */
    020
    021package cascading.tuple.hadoop.util;
    022
    023import java.io.IOException;
    024
    025import cascading.CascadingException;
    026import cascading.tuple.io.IndexTuple;
    027
    028/** Class GroupingComparator is an implementation of {@link org.apache.hadoop.io.RawComparator}. */
    029public class CoGroupingComparator extends DeserializerComparator<IndexTuple>
    030  {
    031  public int compare( byte[] b1, int s1, int l1, byte[] b2, int s2, int l2 )
    032    {
    033    try
    034      {
    035      lhsBuffer.reset( b1, s1, l1 );
    036      rhsBuffer.reset( b2, s2, l2 );
    037
    038      // pop off index
    039      lhsStream.readVInt();
    040      rhsStream.readVInt();
    041
    042      return compareTuples( null, groupComparators );
    043      }
    044    catch( IOException exception )
    045      {
    046      throw new CascadingException( exception );
    047      }
    048    finally
    049      {
    050      lhsBuffer.clear();
    051      rhsBuffer.clear();
    052      }
    053    }
    054
    055  public int compare( IndexTuple lhs, IndexTuple rhs )
    056    {
    057    return compareTuples( groupComparators, lhs.getTuple(), rhs.getTuple() );
    058    }
    059  }