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.io;
022
023import java.io.IOException;
024
025import cascading.tuple.Tuple;
026import cascading.tuple.hadoop.TupleSerialization;
027import cascading.tuple.io.TupleInputStream;
028import cascading.tuple.io.TuplePair;
029
030public class TuplePairDeserializer extends BaseDeserializer<TuplePair>
031  {
032  private final TupleInputStream.TupleElementReader[] keyReaders;
033  private final TupleInputStream.TupleElementReader[] sortReaders;
034
035  public TuplePairDeserializer( TupleSerialization.SerializationElementReader elementReader )
036    {
037    super( elementReader );
038
039    Class[] keyClasses = elementReader.getTupleSerialization().getKeyTypes();
040    Class[] sortClasses = elementReader.getTupleSerialization().getSortTypes();
041
042    if( elementReader.getTupleSerialization().areTypesRequired() )
043      {
044      if( keyClasses == null )
045        throw new IllegalStateException( "types are required to perform serialization, grouping declared fields: " + elementReader.getTupleSerialization().getKeyFields() );
046
047      if( sortClasses == null )
048        throw new IllegalStateException( "types are required to perform serialization, sorting declared fields: " + elementReader.getTupleSerialization().getSortFields() );
049      }
050
051    keyReaders = HadoopTupleInputStream.getReadersFor( elementReader, keyClasses );
052    sortReaders = HadoopTupleInputStream.getReadersFor( elementReader, sortClasses );
053    }
054
055  public TuplePair deserialize( TuplePair tuple ) throws IOException
056    {
057    if( tuple == null )
058      tuple = createTuple();
059
060    Tuple[] tuples = TuplePair.tuples( tuple );
061
062    if( keyReaders == null )
063      tuples[ 0 ] = inputStream.readUnTyped( tuples[ 0 ] );
064    else
065      tuples[ 0 ] = inputStream.readWith( keyReaders, tuples[ 0 ] );
066
067    if( sortReaders == null )
068      tuples[ 1 ] = inputStream.readUnTyped( tuples[ 1 ] );
069    else
070      tuples[ 1 ] = inputStream.readWith( sortReaders, tuples[ 1 ] );
071
072    return tuple;
073    }
074
075  @Override
076  protected TuplePair createTuple()
077    {
078    return new TuplePair();
079    }
080  }