/*
* 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.hadoop.stream.graph;
import cascading.flow.FlowElement;
import cascading.flow.FlowNode;
import cascading.flow.hadoop.HadoopFlowProcess;
import cascading.flow.hadoop.stream.element.HadoopCoGroupGate;
import cascading.flow.hadoop.stream.element.HadoopGroupByGate;
import cascading.flow.hadoop.stream.element.HadoopSinkStage;
import cascading.flow.stream.duct.Duct;
import cascading.flow.stream.duct.Gate;
import cascading.flow.stream.element.SinkStage;
import cascading.flow.stream.graph.IORole;
import cascading.flow.stream.graph.NodeStreamGraph;
import cascading.pipe.CoGroup;
import cascading.pipe.Group;
import cascading.pipe.GroupBy;
import cascading.pipe.HashJoin;
import cascading.tap.Tap;
import cascading.util.Util;
/**
*
*/
public class HadoopReduceStreamGraph extends NodeStreamGraph
{
public HadoopReduceStreamGraph( HadoopFlowProcess flowProcess, FlowNode node, FlowElement sourceElement )
{
super( flowProcess, node, sourceElement );
buildGraph();
setTraps();
setScopes();
printGraph( node.getID(), "reduce", flowProcess.getCurrentSliceNum() );
bind();
}
protected void buildGraph()
{
Group group = (Group) Util.getFirst( node.getSourceElements() );
Duct rhsDuct;
if( group.isGroupBy() )
rhsDuct = new HadoopGroupByGate( flowProcess, (GroupBy) group, IORole.source );
else
rhsDuct = new HadoopCoGroupGate( flowProcess, (CoGroup) group, IORole.source );
addHead( rhsDuct );
handleDuct( group, rhsDuct );
}
@Override
protected SinkStage createSinkStage( Tap element )
{
return new HadoopSinkStage( flowProcess, element );
}
protected Gate createCoGroupGate( CoGroup element, IORole role )
{
throw new IllegalStateException( "should not happen" );
}
@Override
protected Gate createGroupByGate( GroupBy element, IORole role )
{
throw new IllegalStateException( "should not happen" );
}
@Override
protected Gate createHashJoinGate( HashJoin join )
{
throw new IllegalStateException( "should not happen" );
}
}