001/*
002 * Copyright (c) 2007-2015 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
021package cascading.flow.stream.element;
022
023import cascading.CascadingException;
024import cascading.flow.FlowProcess;
025import cascading.flow.stream.duct.Duct;
026import cascading.flow.stream.duct.Reducing;
027import cascading.operation.GroupAssertion;
028import cascading.pipe.Every;
029import cascading.pipe.OperatorException;
030import cascading.tuple.Fields;
031import cascading.tuple.TupleEntry;
032
033/**
034 *
035 */
036public class GroupAssertionEveryStage extends EveryStage<TupleEntry> implements Reducing<TupleEntry, TupleEntry>
037  {
038  private GroupAssertion groupAssertion;
039  private Reducing reducing;
040
041  public GroupAssertionEveryStage( FlowProcess flowProcess, Every every )
042    {
043    super( flowProcess, every );
044    }
045
046  @Override
047  protected Fields getIncomingPassThroughFields()
048    {
049    return incomingScopes.get( 0 ).getIncomingAggregatorPassThroughFields();
050    }
051
052  @Override
053  protected Fields getIncomingArgumentsFields()
054    {
055    return incomingScopes.get( 0 ).getIncomingAggregatorArgumentFields();
056    }
057
058  @Override
059  protected Fields getOutgoingSelector()
060    {
061    return outgoingScopes.get( 0 ).getOutGroupingSelector();
062    }
063
064  @Override
065  public void initialize()
066    {
067    super.initialize();
068
069    groupAssertion = every.getGroupAssertion();
070
071    reducing = (Reducing) getNext();
072    }
073
074  @Override
075  public void startGroup( Duct previous, TupleEntry groupEntry )
076    {
077    operationCall.setGroup( groupEntry );
078    operationCall.setArguments( null );  // zero it out
079    operationCall.setOutputCollector( null ); // zero it out
080
081    try
082      {
083      groupAssertion.start( flowProcess, operationCall );
084      }
085    catch( CascadingException exception )
086      {
087      handleException( exception, groupEntry );
088      }
089    catch( Throwable throwable )
090      {
091      handleException( new OperatorException( every, "operator Every failed starting operation: " + every.getOperation(), throwable ), groupEntry );
092      }
093
094    reducing.startGroup( this, groupEntry );
095    }
096
097  @Override
098  public void receive( Duct previous, TupleEntry tupleEntry )
099    {
100    try
101      {
102      argumentsEntry.setTuple( argumentsBuilder.makeResult( tupleEntry.getTuple(), null ) );
103      operationCall.setArguments( argumentsEntry );
104
105      groupAssertion.aggregate( flowProcess, operationCall );
106      }
107    catch( CascadingException exception )
108      {
109      handleException( exception, argumentsEntry );
110      }
111    catch( Throwable throwable )
112      {
113      handleException( new OperatorException( every, "operator Every failed executing operation: " + every.getOperation(), throwable ), argumentsEntry );
114      }
115
116    next.receive( this, tupleEntry );
117    }
118
119  @Override
120  public void completeGroup( Duct previous, TupleEntry incomingEntry )
121    {
122    this.incomingEntry = incomingEntry;
123    operationCall.setArguments( null );
124
125    try
126      {
127      groupAssertion.doAssert( flowProcess, operationCall ); // collector calls next
128
129      reducing.completeGroup( this, incomingEntry );
130      }
131    catch( CascadingException exception )
132      {
133      handleException( exception, incomingEntry );
134      }
135    catch( Throwable throwable )
136      {
137      handleException( new OperatorException( every, "operator Every failed completing operation: " + every.getOperation(), throwable ), incomingEntry );
138      }
139    }
140  }