/*
* Copyright 2013 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.acceptor.tabu.size;
import org.optaplanner.core.impl.localsearch.scope.LocalSearchStepScope;
public class ValueRatioTabuSizeStrategy extends AbstractTabuSizeStrategy {
protected final double tabuRatio;
public ValueRatioTabuSizeStrategy(double tabuRatio) {
this.tabuRatio = tabuRatio;
if (tabuRatio <= 0.0 || tabuRatio >= 1.0) {
throw new IllegalArgumentException("The tabuRatio (" + tabuRatio
+ ") must be between 0.0 and 1.0.");
}
}
@Override
public int determineTabuSize(LocalSearchStepScope stepScope) {
// TODO we might want to cache the valueCount if and only if moves don't add/remove entities
int valueCount = stepScope.getPhaseScope().getWorkingValueCount();
int tabuSize = (int) Math.round(valueCount * tabuRatio);
return protectTabuSizeCornerCases(valueCount, tabuSize);
}
}