001/*
002 * Copyright (c) 2016 Chris K Wensel <chris@wensel.net>. All Rights Reserved.
003 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
004 *
005 * Project and contact information: http://www.cascading.org/
006 *
007 * This file is part of the Cascading project.
008 *
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *     http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 */
021
022package cascading.flow.stream.element;
023
024import java.io.IOException;
025
026import cascading.CascadingException;
027import cascading.flow.FlowProcess;
028import cascading.flow.stream.duct.Duct;
029import cascading.operation.Function;
030import cascading.pipe.Each;
031import cascading.pipe.OperatorException;
032import cascading.tuple.Fields;
033import cascading.tuple.Tuple;
034import cascading.tuple.TupleEntry;
035import cascading.tuple.TupleEntryCollector;
036import cascading.tuple.Tuples;
037
038/**
039 *
040 */
041public class FunctionEachStage extends EachStage
042  {
043  private Function function;
044
045  public FunctionEachStage( FlowProcess flowProcess, Each each )
046    {
047    super( flowProcess, each );
048    }
049
050  @Override
051  protected Fields getIncomingPassThroughFields()
052    {
053    return incomingScopes.get( 0 ).getIncomingFunctionPassThroughFields();
054    }
055
056  @Override
057  protected Fields getIncomingArgumentsFields()
058    {
059    return incomingScopes.get( 0 ).getIncomingFunctionArgumentFields();
060    }
061
062  @Override
063  public void initialize()
064    {
065    super.initialize();
066
067    function = each.getFunction();
068
069    operationCall.setArguments( argumentsEntry );
070
071    operationCall.setOutputCollector( new TupleEntryCollector( getOperationDeclaredFields() )
072      {
073      @Override
074      protected void collect( TupleEntry input ) throws IOException
075        {
076        Tuple outgoing = outgoingBuilder.makeResult( incomingEntry.getTuple(), input.getTuple() );
077
078        outgoingEntry.setTuple( outgoing );
079
080        try
081          {
082          next.receive( FunctionEachStage.this, 0, outgoingEntry );
083          }
084        finally
085          {
086          Tuples.asModifiable( outgoing );
087          }
088        }
089      } );
090    }
091
092  @Override
093  public void receive( Duct previous, int ordinal, TupleEntry incomingEntry )
094    {
095    this.incomingEntry = incomingEntry;
096
097    argumentsEntry.setTuple( argumentsBuilder.makeResult( incomingEntry.getTuple(), null ) );
098
099    try
100      {
101      function.operate( flowProcess, operationCall ); // adds results to collector
102      }
103    catch( CascadingException exception )
104      {
105      handleException( exception, argumentsEntry );
106      }
107    catch( Throwable throwable )
108      {
109      handleException( new OperatorException( each, "operator Each failed executing operation", throwable ), argumentsEntry );
110      }
111    }
112  }