OriginalOrderNodeComparator.java

/*
 * Copyright 2014 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.exhaustivesearch.node.comparator;

import java.io.Serializable;
import java.util.Comparator;

import org.optaplanner.core.impl.exhaustivesearch.node.ExhaustiveSearchNode;

/**
 * Investigate deeper nodes first, in order.
 */
public class OriginalOrderNodeComparator implements Comparator<ExhaustiveSearchNode>, Serializable {

    @Override
    public int compare(ExhaustiveSearchNode a, ExhaustiveSearchNode b) {
        // Investigate deeper first
        int aDepth = a.getDepth();
        int bDepth = b.getDepth();
        if (aDepth < bDepth) {
            return -1;
        } else if (aDepth > bDepth) {
            return 1;
        }
        // Investigate lower breadth index first (to respect ValueSortingManner)
        return Long.compare(b.getBreadth(), a.getBreadth());
    }

}