/*
* 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.bestsolution;
import org.drools.planner.core.Solver;
import org.drools.planner.core.event.SolverEventSupport;
import org.drools.planner.core.score.Score;
import org.drools.planner.core.solution.Solution;
import org.drools.planner.core.solver.AbstractSolverLifecycleListener;
import org.drools.planner.core.solver.AbstractSolverScope;
import org.drools.planner.core.solver.AbstractStepScope;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A BestSolutionRecaller remembers the best solution that a {@link Solver} encounters.
*/
public class BestSolutionRecaller implements AbstractSolverLifecycleListener {
protected final transient Logger logger = LoggerFactory.getLogger(getClass());
protected SolverEventSupport solverEventSupport;
public void setSolverEventSupport(SolverEventSupport solverEventSupport) {
this.solverEventSupport = solverEventSupport;
}
// ************************************************************************
// Worker methods
// ************************************************************************
public void solvingStarted(AbstractSolverScope abstractSolverScope) {
Score initialScore = abstractSolverScope.calculateScoreFromWorkingMemory();
abstractSolverScope.setStartingScore(initialScore);
abstractSolverScope.setBestSolutionStepIndex(-1);
Solution newBestSolution = abstractSolverScope.getWorkingSolution().cloneSolution();
abstractSolverScope.setBestSolution(newBestSolution);
abstractSolverScope.setBestScore(initialScore);
solverEventSupport.fireBestSolutionChanged(newBestSolution); // TODO if solution is initialized it should not fire an event
}
public void stepTaken(AbstractStepScope abstractStepScope) {
AbstractSolverScope abstractSolverScope = abstractStepScope.getAbstractSolverScope();
Score newScore = abstractStepScope.getScore();
Score bestScore = abstractSolverScope.getBestScore();
boolean bestScoreImproved = newScore.compareTo(bestScore) > 0;
abstractStepScope.setBestScoreImproved(bestScoreImproved);
if (bestScoreImproved) {
abstractSolverScope.setBestSolutionStepIndex(abstractStepScope.getStepIndex());
Solution newBestSolution = abstractStepScope.createOrGetClonedSolution();
abstractSolverScope.setBestSolution(newBestSolution);
abstractSolverScope.setBestScore(newBestSolution.getScore());
solverEventSupport.fireBestSolutionChanged(newBestSolution);
}
}
public void solvingEnded(AbstractSolverScope abstractSolverScope) {
}
}