/*
* Copyright 2011 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.optaplanner.core.impl.localsearch;
import org.optaplanner.core.impl.heuristic.move.Move;
import org.optaplanner.core.impl.localsearch.decider.LocalSearchDecider;
import org.optaplanner.core.impl.localsearch.event.LocalSearchPhaseLifecycleListener;
import org.optaplanner.core.impl.localsearch.scope.LocalSearchPhaseScope;
import org.optaplanner.core.impl.localsearch.scope.LocalSearchStepScope;
import org.optaplanner.core.impl.phase.AbstractPhase;
import org.optaplanner.core.impl.solver.scope.DefaultSolverScope;
/**
* Default implementation of {@link LocalSearchPhase}.
*/
public class DefaultLocalSearchPhase extends AbstractPhase implements LocalSearchPhase,
LocalSearchPhaseLifecycleListener {
protected LocalSearchDecider decider;
protected boolean assertStepScoreFromScratch = false;
protected boolean assertExpectedStepScore = false;
public LocalSearchDecider getDecider() {
return decider;
}
public void setDecider(LocalSearchDecider decider) {
this.decider = decider;
}
public void setAssertStepScoreFromScratch(boolean assertStepScoreFromScratch) {
this.assertStepScoreFromScratch = assertStepScoreFromScratch;
}
public void setAssertExpectedStepScore(boolean assertExpectedStepScore) {
this.assertExpectedStepScore = assertExpectedStepScore;
}
// ************************************************************************
// Worker methods
// ************************************************************************
public void solve(DefaultSolverScope solverScope) {
LocalSearchPhaseScope phaseScope = new LocalSearchPhaseScope(solverScope);
phaseStarted(phaseScope);
while (!termination.isPhaseTerminated(phaseScope)) {
LocalSearchStepScope stepScope = new LocalSearchStepScope(phaseScope);
stepScope.setTimeGradient(termination.calculatePhaseTimeGradient(phaseScope));
stepStarted(stepScope);
decider.decideNextStep(stepScope);
if (stepScope.getStep() == null) {
if (termination.isPhaseTerminated(phaseScope)) {
logger.trace(" Step index ({}), time spent ({}) terminated without picking a nextStep.",
stepScope.getStepIndex(),
stepScope.getPhaseScope().calculateSolverTimeMillisSpent());
} else if (stepScope.getSelectedMoveCount() == 0L) {
logger.warn(" No doable selected move at step index ({}), time spent ({})."
+ " Terminating phase early.",
stepScope.getStepIndex(),
stepScope.getPhaseScope().calculateSolverTimeMillisSpent());
} else {
throw new IllegalStateException("The step index (" + stepScope.getStepIndex()
+ ") has accepted/selected move count (" + stepScope.getAcceptedMoveCount() + "/"
+ stepScope.getSelectedMoveCount()
+ ") but failed to pick a nextStep (" + stepScope.getStep() + ").");
}
// Although stepStarted has been called, stepEnded is not called for this step
break;
}
doStep(stepScope);
stepEnded(stepScope);
phaseScope.setLastCompletedStepScope(stepScope);
}
phaseEnded(phaseScope);
}
private void doStep(LocalSearchStepScope stepScope) {
LocalSearchPhaseScope phaseScope = stepScope.getPhaseScope();
Move nextStep = stepScope.getStep();
nextStep.doMove(stepScope.getScoreDirector());
// there is no need to recalculate the score, but we still need to set it
phaseScope.getWorkingSolution().setScore(stepScope.getScore());
if (assertStepScoreFromScratch) {
phaseScope.assertWorkingScoreFromScratch(stepScope.getScore(), nextStep);
}
if (assertExpectedStepScore) {
phaseScope.assertExpectedWorkingScore(stepScope.getScore(), nextStep);
}
bestSolutionRecaller.processWorkingSolutionDuringStep(stepScope);
}
@Override
public void solvingStarted(DefaultSolverScope solverScope) {
super.solvingStarted(solverScope);
decider.solvingStarted(solverScope);
}
public void phaseStarted(LocalSearchPhaseScope phaseScope) {
super.phaseStarted(phaseScope);
decider.phaseStarted(phaseScope);
// TODO maybe this restriction should be lifted to allow LocalSearch to initialize a solution too?
if (!phaseScope.getScoreDirector().isWorkingSolutionInitialized()) {
throw new IllegalStateException("Local Search phase started with an uninitialized Solution." +
" First initialize the Solution. For example, run a Construction Heuristic phase first.");
}
}
public void stepStarted(LocalSearchStepScope stepScope) {
super.stepStarted(stepScope);
decider.stepStarted(stepScope);
}
public void stepEnded(LocalSearchStepScope stepScope) {
super.stepEnded(stepScope);
decider.stepEnded(stepScope);
LocalSearchPhaseScope phaseScope = stepScope.getPhaseScope();
if (logger.isDebugEnabled()) {
long timeMillisSpent = phaseScope.calculateSolverTimeMillisSpent();
logger.debug(" LS step ({}), time spent ({}), score ({}), {} best score ({})," +
" accepted/selected move count ({}/{}), picked move ({}).",
stepScope.getStepIndex(), timeMillisSpent,
stepScope.getScore(),
(stepScope.getBestScoreImproved() ? "new" : " "), phaseScope.getBestScore(),
stepScope.getAcceptedMoveCount(),
stepScope.getSelectedMoveCount(),
stepScope.getStepString());
}
}
public void phaseEnded(LocalSearchPhaseScope phaseScope) {
super.phaseEnded(phaseScope);
decider.phaseEnded(phaseScope);
logger.info("Local Search phase ({}) ended: step total ({}), time spent ({}), best score ({}).",
phaseIndex,
phaseScope.getNextStepIndex(),
phaseScope.calculateSolverTimeMillisSpent(),
phaseScope.getBestScore());
}
@Override
public void solvingEnded(DefaultSolverScope solverScope) {
super.solvingEnded(solverScope);
decider.solvingEnded(solverScope);
}
}