/*
* Copyright 2012 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.decider.acceptor.stepcountinghillclimbing;
import org.optaplanner.core.api.score.Score;
import org.optaplanner.core.config.localsearch.decider.acceptor.stepcountinghillclimbing.StepCountingHillClimbingType;
import org.optaplanner.core.impl.localsearch.decider.acceptor.AbstractAcceptor;
import org.optaplanner.core.impl.localsearch.scope.LocalSearchMoveScope;
import org.optaplanner.core.impl.localsearch.scope.LocalSearchPhaseScope;
import org.optaplanner.core.impl.localsearch.scope.LocalSearchStepScope;
public class StepCountingHillClimbingAcceptor extends AbstractAcceptor {
protected int stepCountingHillClimbingSize = -1;
protected StepCountingHillClimbingType stepCountingHillClimbingType;
protected Score thresholdScore;
protected int count = -1;
public StepCountingHillClimbingAcceptor(int stepCountingHillClimbingSize,
StepCountingHillClimbingType stepCountingHillClimbingType) {
this.stepCountingHillClimbingSize = stepCountingHillClimbingSize;
this.stepCountingHillClimbingType = stepCountingHillClimbingType;
if (stepCountingHillClimbingSize <= 0) {
throw new IllegalArgumentException("The stepCountingHillClimbingSize (" + stepCountingHillClimbingSize
+ ") cannot be negative or zero.");
}
if (stepCountingHillClimbingType == null) {
throw new IllegalArgumentException("The stepCountingHillClimbingType (" + stepCountingHillClimbingType
+ ") cannot be null.");
}
}
// ************************************************************************
// Worker methods
// ************************************************************************
@Override
public void phaseStarted(LocalSearchPhaseScope phaseScope) {
super.phaseStarted(phaseScope);
thresholdScore = phaseScope.getBestScore();
count = 0;
}
public boolean isAccepted(LocalSearchMoveScope moveScope) {
Score lastStepScore = moveScope.getStepScope().getPhaseScope().getLastCompletedStepScope().getScore();
Score moveScore = moveScope.getScore();
if (moveScore.compareTo(lastStepScore) >= 0) {
return true;
}
return moveScore.compareTo(thresholdScore) >= 0;
}
@Override
public void stepEnded(LocalSearchStepScope stepScope) {
super.stepEnded(stepScope);
count += determineCountIncrement(stepScope);
if (count >= stepCountingHillClimbingSize) {
thresholdScore = stepScope.getScore();
count = 0;
}
}
private int determineCountIncrement(LocalSearchStepScope stepScope) {
switch (stepCountingHillClimbingType) {
case SELECTED_MOVE:
long selectedMoveCount = stepScope.getSelectedMoveCount();
return selectedMoveCount > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int) selectedMoveCount;
case ACCEPTED_MOVE:
long acceptedMoveCount = stepScope.getAcceptedMoveCount();
return acceptedMoveCount > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int) acceptedMoveCount;
case STEP:
return 1;
case EQUAL_OR_IMPROVING_STEP:
return stepScope.getScore().compareTo(
stepScope.getPhaseScope().getLastCompletedStepScope().getScore()) >= 0 ? 1 : 0;
case IMPROVING_STEP:
return stepScope.getScore().compareTo(
stepScope.getPhaseScope().getLastCompletedStepScope().getScore()) > 0 ? 1 : 0;
default:
throw new IllegalStateException("The stepCountingHillClimbingType (" + stepCountingHillClimbingType
+ ") is not implemented.");
}
}
@Override
public void phaseEnded(LocalSearchPhaseScope phaseScope) {
super.phaseEnded(phaseScope);
thresholdScore = null;
count = -1;
}
}