bookkeeper-server/src/main/java/org/apache/bookkeeper/meta/ZkVersion.java

/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.bookkeeper.meta;

import org.apache.bookkeeper.versioning.Version;
import org.apache.bookkeeper.versioning.Version.Occurred;

public class ZkVersion implements Version {
    int znodeVersion;

    public ZkVersion(int version) {
        znodeVersion = version;
    }

    @Override
    public Occurred compare(Version v) {
        if (null == v) {
            throw new NullPointerException("Version is not allowed to be null.");
        }
        if (v == Version.NEW) {
            return Occurred.AFTER;
        } else if (v == Version.ANY) {
            return Occurred.CONCURRENTLY;
        } else if (!(v instanceof ZkVersion)) {
            throw new IllegalArgumentException("Invalid version type");
        }
        ZkVersion zv = (ZkVersion)v;
        int res = znodeVersion - zv.znodeVersion;
        if (res == 0) {
            return Occurred.CONCURRENTLY;
        } else if (res < 0) {
            return Occurred.BEFORE;
        } else {
            return Occurred.AFTER;
        }
    }

    public int getZnodeVersion() {
        return znodeVersion;
    }

    public ZkVersion setZnodeVersion(int znodeVersion) {
        this.znodeVersion = znodeVersion;
        return this;
    }

    @Override
    public String toString() {
        return Integer.toString(znodeVersion, 10);
    }
}