/*
* Copyright 2006 JBoss Inc
*
* 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 org.drools.reteoo.builder;
import java.util.ArrayList;
import java.util.List;
import org.drools.common.BetaConstraints;
import org.drools.common.TupleStartEqualsConstraint;
import org.drools.reteoo.AccumulateNode;
import org.drools.reteoo.ObjectSource;
import org.drools.reteoo.RightInputAdapterNode;
import org.drools.reteoo.TupleSource;
import org.drools.rule.Accumulate;
import org.drools.rule.RuleConditionElement;
import org.drools.spi.AlphaNodeFieldConstraint;
/**
* @author etirelli
*
*/
public class AccumulateBuilder
implements
ReteooComponentBuilder {
/**
* @inheritDoc
*/
public void build(final BuildContext context,
final BuildUtils utils,
final RuleConditionElement rce) {
final Accumulate accumulate = (Accumulate) rce;
boolean existSubNetwort = false;
final List resultBetaConstraints = context.getBetaconstraints();
final List resultAlphaConstraints = context.getAlphaConstraints();
final RuleConditionElement source = accumulate.getSource();
// get builder for the pattern
final ReteooComponentBuilder builder = utils.getBuilderFor( source );
// save tuple source and current pattern offset for later if needed
final TupleSource tupleSource = context.getTupleSource();
final int currentPatternIndex = context.getCurrentPatternOffset();
// builds the source pattern
builder.build( context,
utils,
source );
// if object source is null, then we need to adapt tuple source into a subnetwork
if ( context.getObjectSource() == null ) {
// attach right input adapter node to convert tuple source into an object source
context.setObjectSource( (ObjectSource) utils.attachNode( context,
new RightInputAdapterNode( context.getNextId(),
context.getTupleSource(),
context ) ) );
// restore tuple source from before the start of the sub network
context.setTupleSource( tupleSource );
// create a tuple start equals constraint and set it in the context
final TupleStartEqualsConstraint constraint = TupleStartEqualsConstraint.getInstance();
final List betaConstraints = new ArrayList();
betaConstraints.add( constraint );
context.setBetaconstraints( betaConstraints );
existSubNetwort = true;
}
final BetaConstraints resultsBinder = utils.createBetaNodeConstraint( context,
resultBetaConstraints,
true );
final BetaConstraints sourceBinder = utils.createBetaNodeConstraint( context,
context.getBetaconstraints(),
false );
context.setTupleSource( (TupleSource) utils.attachNode( context,
new AccumulateNode( context.getNextId(),
context.getTupleSource(),
context.getObjectSource(),
(AlphaNodeFieldConstraint[]) resultAlphaConstraints.toArray( new AlphaNodeFieldConstraint[resultAlphaConstraints.size()] ),
sourceBinder,
resultsBinder,
accumulate,
existSubNetwort,
context ) ) );
// source pattern was bound, so nulling context
context.setObjectSource( null );
context.setCurrentPatternOffset( currentPatternIndex );
}
/**
* @inheritDoc
*/
public boolean requiresLeftActivation(final BuildUtils utils,
final RuleConditionElement rce) {
return true;
}
}