/**
* 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.bestsolution;
import org.drools.planner.core.localsearch.LocalSearchSolver;
import org.drools.planner.core.localsearch.LocalSearchSolverAware;
import org.drools.planner.core.localsearch.LocalSearchSolverLifecycleListener;
import org.drools.planner.core.localsearch.LocalSearchSolverScope;
import org.drools.planner.core.localsearch.StepScope;
import org.drools.planner.core.score.Score;
import org.drools.planner.core.event.SolverEventSupport;
import org.drools.planner.core.solution.Solution;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A BestSolutionRecaller remembers the best solution that the LocalSearchSolver encounters.
* @author Geoffrey De Smet
*/
public class BestSolutionRecaller implements LocalSearchSolverAware, LocalSearchSolverLifecycleListener {
protected final transient Logger logger = LoggerFactory.getLogger(getClass());
protected LocalSearchSolver localSearchSolver;
protected SolverEventSupport solverEventSupport;
public void setLocalSearchSolver(LocalSearchSolver localSearchSolver) {
this.localSearchSolver = localSearchSolver;
}
public void setSolverEventSupport(SolverEventSupport solverEventSupport) {
this.solverEventSupport = solverEventSupport;
}
// ************************************************************************
// Worker methods
// ************************************************************************
public void solvingStarted(LocalSearchSolverScope localSearchSolverScope) {
Score initialScore = localSearchSolverScope.getStartingScore();
logger.info("Initialization time spend ({}) for score ({}). Updating best solution and best score.",
localSearchSolverScope.calculateTimeMillisSpend(), initialScore);
localSearchSolverScope.setBestSolutionStepIndex(-1);
localSearchSolverScope.setBestSolution(localSearchSolverScope.getWorkingSolution().cloneSolution());
localSearchSolverScope.setBestScore(initialScore);
}
public void beforeDeciding(StepScope stepScope) {
}
public void stepDecided(StepScope stepScope) {
}
public void stepTaken(StepScope stepScope) {
LocalSearchSolverScope localSearchSolverScope = stepScope.getLocalSearchSolverScope();
Score newScore = stepScope.getScore();
Score bestScore = localSearchSolverScope.getBestScore();
if (newScore.compareTo(bestScore) > 0) {
logger.info("New score ({}) is better then last best score ({}). Updating best solution and best score.",
newScore, bestScore);
localSearchSolverScope.setBestSolutionStepIndex(stepScope.getStepIndex());
Solution newBestSolution = stepScope.createOrGetClonedSolution();
localSearchSolverScope.setBestSolution(newBestSolution);
localSearchSolverScope.setBestScore(newBestSolution.getScore());
solverEventSupport.fireBestSolutionChanged(newBestSolution);
} else {
logger.info("New score ({}) is not better then last best score ({}).", newScore, bestScore);
}
}
public void solvingEnded(LocalSearchSolverScope localSearchSolverScope) {
}
}