/*
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*
* 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.forager;
import java.util.List;
import org.optaplanner.core.api.score.Score;
import org.optaplanner.core.config.localsearch.decider.forager.LocalSearchPickEarlyType;
import org.optaplanner.core.impl.localsearch.decider.acceptor.Acceptor;
import org.optaplanner.core.impl.localsearch.decider.forager.finalist.FinalistPodium;
import org.optaplanner.core.impl.localsearch.scope.LocalSearchMoveScope;
import org.optaplanner.core.impl.localsearch.scope.LocalSearchPhaseScope;
import org.optaplanner.core.impl.localsearch.scope.LocalSearchStepScope;
import org.optaplanner.core.impl.solver.scope.DefaultSolverScope;
/**
* A {@link Forager} which forages accepted moves and ignores unaccepted moves.
* @see Forager
* @see Acceptor
*/
public class AcceptedForager extends AbstractForager {
protected final FinalistPodium finalistPodium;
protected final LocalSearchPickEarlyType pickEarlyType;
protected final int acceptedCountLimit;
protected final boolean breakTieRandomly;
protected long selectedMoveCount;
protected long acceptedMoveCount;
protected LocalSearchMoveScope earlyPickedMoveScope;
public AcceptedForager(FinalistPodium finalistPodium,
LocalSearchPickEarlyType pickEarlyType, int acceptedCountLimit, boolean breakTieRandomly) {
this.finalistPodium = finalistPodium;
this.pickEarlyType = pickEarlyType;
this.acceptedCountLimit = acceptedCountLimit;
if (acceptedCountLimit < 1) {
throw new IllegalArgumentException("The acceptedCountLimit (" + acceptedCountLimit
+ ") cannot be negative or zero.");
}
this.breakTieRandomly = breakTieRandomly;
}
// ************************************************************************
// Worker methods
// ************************************************************************
@Override
public void solvingStarted(DefaultSolverScope solverScope) {
super.solvingStarted(solverScope);
finalistPodium.solvingStarted(solverScope);
}
@Override
public void phaseStarted(LocalSearchPhaseScope phaseScope) {
super.phaseStarted(phaseScope);
finalistPodium.phaseStarted(phaseScope);
}
@Override
public void stepStarted(LocalSearchStepScope stepScope) {
super.stepStarted(stepScope);
finalistPodium.stepStarted(stepScope);
selectedMoveCount = 0L;
acceptedMoveCount = 0L;
earlyPickedMoveScope = null;
}
@Override
public boolean supportsNeverEndingMoveSelector() {
// TODO FIXME magical value Integer.MAX_VALUE coming from ForagerConfig
return acceptedCountLimit < Integer.MAX_VALUE;
}
@Override
public void addMove(LocalSearchMoveScope moveScope) {
selectedMoveCount++;
if (moveScope.getAccepted()) {
acceptedMoveCount++;
checkPickEarly(moveScope);
}
finalistPodium.addMove(moveScope);
}
protected void checkPickEarly(LocalSearchMoveScope moveScope) {
switch (pickEarlyType) {
case NEVER:
break;
case FIRST_BEST_SCORE_IMPROVING:
Score bestScore = moveScope.getStepScope().getPhaseScope().getBestScore();
if (moveScope.getScore().compareTo(bestScore) > 0) {
earlyPickedMoveScope = moveScope;
}
break;
case FIRST_LAST_STEP_SCORE_IMPROVING:
Score lastStepScore = moveScope.getStepScope().getPhaseScope()
.getLastCompletedStepScope().getScore();
if (moveScope.getScore().compareTo(lastStepScore) > 0) {
earlyPickedMoveScope = moveScope;
}
break;
default:
throw new IllegalStateException("The pickEarlyType (" + pickEarlyType + ") is not implemented.");
}
}
@Override
public boolean isQuitEarly() {
return earlyPickedMoveScope != null || acceptedMoveCount >= acceptedCountLimit;
}
@Override
public LocalSearchMoveScope pickMove(LocalSearchStepScope stepScope) {
stepScope.setSelectedMoveCount(selectedMoveCount);
stepScope.setAcceptedMoveCount(acceptedMoveCount);
if (earlyPickedMoveScope != null) {
return earlyPickedMoveScope;
}
List<LocalSearchMoveScope> finalistList = finalistPodium.getFinalistList();
if (finalistList.isEmpty()) {
return null;
}
if (finalistList.size() == 1 || !breakTieRandomly) {
return finalistList.get(0);
}
int randomIndex = stepScope.getWorkingRandom().nextInt(finalistList.size());
return finalistList.get(randomIndex);
}
@Override
public void stepEnded(LocalSearchStepScope stepScope) {
super.stepEnded(stepScope);
finalistPodium.stepEnded(stepScope);
}
@Override
public void phaseEnded(LocalSearchPhaseScope phaseScope) {
super.phaseEnded(phaseScope);
finalistPodium.phaseEnded(phaseScope);
selectedMoveCount = 0L;
acceptedMoveCount = 0L;
earlyPickedMoveScope = null;
}
@Override
public void solvingEnded(DefaultSolverScope solverScope) {
super.solvingEnded(solverScope);
finalistPodium.solvingEnded(solverScope);
}
@Override
public String toString() {
return getClass().getSimpleName() + "(" + pickEarlyType + ", " + acceptedCountLimit + ")";
}
}