    001    /*
    002     * Copyright (c) 2007-2014 Concurrent, 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
    021    package cascading.tuple.hadoop.util;
    022
    023    import java.io.IOException;
    024
    025    import cascading.CascadingException;
    026    import cascading.tuple.io.TuplePair;
    027
    028    /** Class GroupingComparator is an implementation of {@link org.apache.hadoop.io.RawComparator}. */
    029    public class GroupingComparator extends DeserializerComparator<TuplePair>
    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          // only compare the first tuple in the pair
    039          return compareTuples( groupComparators );
    040          }
    041        catch( IOException exception )
    042          {
    043          throw new CascadingException( exception );
    044          }
    045        finally
    046          {
    047          lhsBuffer.clear();
    048          rhsBuffer.clear();
    049          }
    050        }
    051
    052      public int compare( TuplePair lhs, TuplePair rhs )
    053        {
    054        return compareTuples( groupComparators, lhs.getLhs(), rhs.getLhs() );
    055        }
    056      }