/*
 * Copyright (c) 2000, 2017 Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2021 Contributors to the Eclipse Foundation
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

/*
 * @(#)RefCompare.java	1.5 06/28/07
 */

package com.sun.messaging.jmq.jmsserver.data.handlers;

import java.io.Serializable;
import java.util.*;
import com.sun.messaging.jmq.jmsserver.core.PacketReference;

public class RefCompare implements Comparator, Serializable {
    /**
     * 
     */
    private static final long serialVersionUID = -8384036651423700587L;

    @Override
    public int compare(Object o1, Object o2) {
        if (o1 instanceof PacketReference && o2 instanceof PacketReference) {
            PacketReference ref1 = (PacketReference) o1;
            PacketReference ref2 = (PacketReference) o2;
            // compare priority
            long dif = ref2.getPriority() - ref1.getPriority();

            // then timestamp
            if (dif == 0) {
                dif = ref1.getTimestamp() - ref2.getTimestamp();
            }

            // then sequence
            if (dif == 0) {
                dif = ref1.getSequence() - ref2.getSequence();
            }

            if (dif < 0) {
                return -1;
            }
            if (dif > 0) {
                return 1;
            }
            return 0;
        }
        return o2.hashCode() - o1.hashCode();
    }
}
