org.drools.planner.core.localsearch.decider.acceptor.tabu.SolutionTabuAcceptor Maven / Gradle / Ivy
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Drools Planner optimizes automated planning by combining metaheuristic search algorithms with rule
engine powered score calculation. This is the drools-planner-core module which contains metaheuristic
algorithms.
/*
* Copyright 2010 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.planner.core.localsearch.decider.acceptor.tabu;
import java.util.Collection;
import java.util.Collections;
import org.drools.planner.core.localsearch.LocalSearchSolverPhaseScope;
import org.drools.planner.core.localsearch.LocalSearchStepScope;
import org.drools.planner.core.localsearch.decider.MoveScope;
public class SolutionTabuAcceptor extends AbstractTabuAcceptor {
public SolutionTabuAcceptor() {
// Disable aspiration by default because it's useless on solution tabu
aspirationEnabled = false;
}
// ************************************************************************
// Worker methods
// ************************************************************************
@Override
protected Collection findTabu(MoveScope moveScope) {
return Collections.singletonList(moveScope.getWorkingSolution());
}
@Override
protected Collection findNewTabu(LocalSearchStepScope localSearchStepScope) {
// TODO this should be better done in stepTaken
return Collections.singletonList(localSearchStepScope.createOrGetClonedSolution());
}
@Override
public void phaseStarted(LocalSearchSolverPhaseScope localSearchSolverPhaseScope) {
super.phaseStarted(localSearchSolverPhaseScope);
// Add the starting solution to the tabu list
Object tabu = localSearchSolverPhaseScope.getWorkingSolution().cloneSolution();
tabuToStepIndexMap.put(tabu, 0); // TODO should -1 when AbstractTabuAcceptor can handle that
tabuSequenceList.add(tabu);
}
}