| /* |
| * Copyright 2017-present Open Networking Laboratory |
| * |
| * 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.onosproject.store.service; |
| |
| import java.util.Objects; |
| |
| import com.google.common.base.MoreObjects; |
| import com.google.common.collect.ComparisonChain; |
| import org.onosproject.store.Timestamp; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| |
| /** |
| * Logical timestamp for versions. |
| * <p> |
| * The version is a logical timestamp that represents a point in logical time at which an event occurs. |
| * This is used in both pessimistic and optimistic locking protocols to ensure that the state of a shared resource |
| * has not changed at the end of a transaction. |
| */ |
| public class Version implements Timestamp { |
| private final long version; |
| |
| public Version(long version) { |
| this.version = version; |
| } |
| |
| @Override |
| public int compareTo(Timestamp o) { |
| checkArgument(o instanceof Version, |
| "Must be LockVersion", o); |
| Version that = (Version) o; |
| |
| return ComparisonChain.start() |
| .compare(this.version, that.version) |
| .result(); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Long.hashCode(version); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if (!(obj instanceof Version)) { |
| return false; |
| } |
| Version that = (Version) obj; |
| return Objects.equals(this.version, that.version); |
| } |
| |
| @Override |
| public String toString() { |
| return MoreObjects.toStringHelper(getClass()) |
| .add("version", version) |
| .toString(); |
| } |
| |
| /** |
| * Returns the lock version. |
| * |
| * @return the lock version |
| */ |
| public long value() { |
| return this.version; |
| } |
| } |