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.flow.hadoop.stream;
022    
023    import java.util.IdentityHashMap;
024    import java.util.Map;
025    
026    import cascading.CascadingException;
027    import cascading.flow.FlowProcess;
028    import cascading.flow.SliceCounters;
029    import cascading.flow.hadoop.HadoopCoGroupClosure;
030    import cascading.flow.stream.Duct;
031    import cascading.flow.stream.DuctException;
032    import cascading.flow.stream.SpliceGate;
033    import cascading.flow.stream.StreamGraph;
034    import cascading.pipe.CoGroup;
035    import cascading.tuple.Tuple;
036    import cascading.tuple.TupleEntry;
037    import cascading.tuple.io.IndexTuple;
038    import cascading.tuple.io.TuplePair;
039    
040    /**
041     *
042     */
043    public class HadoopCoGroupGate extends HadoopGroupGate
044      {
045      private final Map<Duct, Integer> posMap = new IdentityHashMap<Duct, Integer>();
046    
047      public HadoopCoGroupGate( FlowProcess flowProcess, CoGroup coGroup, SpliceGate.Role role )
048        {
049        super( flowProcess, coGroup, role );
050        }
051    
052      @Override
053      public void bind( StreamGraph streamGraph )
054        {
055        super.bind( streamGraph );
056    
057        if( role == Role.sink )
058          orderDucts( streamGraph );
059        }
060    
061      @Override
062      public void prepare()
063        {
064        super.prepare();
065    
066        if( role != Role.sink )
067          closure = new HadoopCoGroupClosure( flowProcess, splice.getNumSelfJoins(), keyFields, valuesFields );
068        else
069          makePosMap( posMap );
070    
071        if( grouping != null && splice.getJoinDeclaredFields() != null && splice.getJoinDeclaredFields().isNone() )
072          grouping.joinerClosure = closure;
073        }
074    
075      @Override
076      public void receive( Duct previous, TupleEntry incomingEntry )
077        {
078        Integer pos = posMap.get( previous );
079    
080        Tuple groupTuple = keyBuilder[ pos ].makeResult( incomingEntry.getTuple(), null );
081        Tuple sortTuple = sortFields == null ? null : sortBuilder[ pos ].makeResult( incomingEntry.getTuple(), null );
082        Tuple valuesTuple = valuesBuilder[ pos ].makeResult( incomingEntry.getTuple(), null );
083    
084        Tuple groupKey = sortTuple == null ? groupTuple : new TuplePair( groupTuple, sortTuple );
085    
086        try
087          {
088          collector.collect( new IndexTuple( pos, groupKey ), new IndexTuple( pos, valuesTuple ) );
089          flowProcess.increment( SliceCounters.Tuples_Written, 1 );
090          }
091        catch( OutOfMemoryError error )
092          {
093          handleReThrowableException( "out of memory, try increasing task memory allocation", error );
094          }
095        catch( CascadingException exception )
096          {
097          handleException( exception, incomingEntry );
098          }
099        catch( Throwable throwable )
100          {
101          handleException( new DuctException( "internal error: " + incomingEntry.getTuple().print(), throwable ), incomingEntry );
102          }
103        }
104    
105      @Override
106      protected Tuple unwrapGrouping( Tuple key )
107        {
108        return ( (IndexTuple) key ).getTuple();
109        }
110      }