/*
* Copyright (c) 2007-2014 Concurrent, 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.flow.stream.element;
import java.io.IOException;
import cascading.CascadingException;
import cascading.flow.FlowProcess;
import cascading.flow.stream.duct.Duct;
import cascading.operation.Function;
import cascading.pipe.Each;
import cascading.pipe.OperatorException;
import cascading.tuple.Fields;
import cascading.tuple.Tuple;
import cascading.tuple.TupleEntry;
import cascading.tuple.TupleEntryCollector;
import cascading.tuple.Tuples;
/**
*
*/
public class FunctionEachStage extends EachStage
{
private Function function;
public FunctionEachStage( FlowProcess flowProcess, Each each )
{
super( flowProcess, each );
}
@Override
protected Fields getIncomingPassThroughFields()
{
return incomingScopes.get( 0 ).getIncomingFunctionPassThroughFields();
}
@Override
protected Fields getIncomingArgumentsFields()
{
return incomingScopes.get( 0 ).getIncomingFunctionArgumentFields();
}
@Override
public void initialize()
{
super.initialize();
function = each.getFunction();
operationCall.setArguments( argumentsEntry );
operationCall.setOutputCollector( new TupleEntryCollector( getOperationDeclaredFields() )
{
@Override
protected void collect( TupleEntry input ) throws IOException
{
Tuple outgoing = outgoingBuilder.makeResult( incomingEntry.getTuple(), input.getTuple() );
outgoingEntry.setTuple( outgoing );
try
{
next.receive( FunctionEachStage.this, outgoingEntry );
}
finally
{
Tuples.asModifiable( outgoing );
}
}
} );
}
@Override
public void receive( Duct previous, TupleEntry incomingEntry )
{
this.incomingEntry = incomingEntry;
argumentsEntry.setTuple( argumentsBuilder.makeResult( incomingEntry.getTuple(), null ) );
try
{
function.operate( flowProcess, operationCall ); // adds results to collector
}
catch( CascadingException exception )
{
handleException( exception, argumentsEntry );
}
catch( Throwable throwable )
{
handleException( new OperatorException( each, "operator Each failed executing operation", throwable ), argumentsEntry );
}
}
}