/*
* Copyright (c) 2007-2013 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.pattern.model.tree;
import cascading.flow.FlowProcess;
import cascading.operation.FunctionCall;
import cascading.operation.OperationCall;
import cascading.pattern.model.ModelScoringFunction;
import cascading.pattern.model.tree.decision.DecisionTree;
import cascading.pattern.model.tree.decision.FinalDecision;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** Class TreeFunction will return the result or score from the given decision tree defined by the {@link TreeSpec}. */
public class TreeFunction extends ModelScoringFunction<TreeSpec, DecisionTree>
{
private static final Logger LOG = LoggerFactory.getLogger( TreeFunction.class );
Result<FinalDecision, ?> result;
public TreeFunction( TreeSpec treeSpec )
{
this( treeSpec, false, SAFE_DEFAULT );
}
public TreeFunction( TreeSpec spec, boolean returnIndex, boolean safe )
{
super( spec, safe );
if( returnIndex )
result = new Result<FinalDecision, Integer>()
{
@Override
public Integer transform( FinalDecision finalDecision )
{
return finalDecision.getIndex();
}
};
else
result = new Result<FinalDecision, Object>()
{
@Override
public Object transform( FinalDecision finalDecision )
{
return finalDecision.getScore();
}
};
}
@Override
public void prepare( FlowProcess flowProcess, OperationCall<Context<DecisionTree>> operationCall )
{
super.prepare( flowProcess, operationCall );
operationCall.getContext().payload = getSpec().getTree().createDecisionTree( getSpec().getCategoriesArray(), operationCall.getArgumentFields() );
}
@Override
public void operate( FlowProcess flowProcess, FunctionCall<Context<DecisionTree>> functionCall )
{
DecisionTree decisionTree = functionCall.getContext().payload;
FinalDecision finalDecision = decisionTree.decide( functionCall.getArguments() );
LOG.debug( "decision: {}", finalDecision );
Object result = this.result.transform( finalDecision );
functionCall.getOutputCollector().add( functionCall.getContext().result( result ) );
}
}