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An API for data management, analytics, and machine learning on parallel computing clusters.

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/*
 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
 *
 * Project and contact information: http://www.cascading.org/
 *
 * This file is part of the Cascading project.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cascading.tuple.hadoop.util;

import java.io.IOException;

import cascading.CascadingException;
import cascading.tuple.io.TuplePair;

/** Class GroupingComparator is an implementation of {@link org.apache.hadoop.io.RawComparator}. */
public class GroupingComparator extends DeserializerComparator
  {
  public int compare( byte[] b1, int s1, int l1, byte[] b2, int s2, int l2 )
    {
    try
      {
      lhsBuffer.reset( b1, s1, l1 );
      rhsBuffer.reset( b2, s2, l2 );

      // only compare the first tuple in the pair
      return compareTuples( keyTypes, groupComparators );
      }
    catch( IOException exception )
      {
      throw new CascadingException( exception );
      }
    finally
      {
      lhsBuffer.clear();
      rhsBuffer.clear();
      }
    }

  public int compare( TuplePair lhs, TuplePair rhs )
    {
    return compareTuples( groupComparators, lhs.getLhs(), rhs.getLhs() );
    }
  }