| /* |
| * Copyright 2018-present Open Networking Foundation |
| * |
| * 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.flow.impl; |
| |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| import org.onosproject.store.LogicalTimestamp; |
| |
| /** |
| * Logical clock. |
| */ |
| public final class LogicalClock { |
| private final AtomicLong timestamp = new AtomicLong(); |
| |
| /** |
| * Records an event. |
| * |
| * @param timestamp the event timestamp |
| */ |
| public void tick(LogicalTimestamp timestamp) { |
| this.timestamp.accumulateAndGet(timestamp.value(), (x, y) -> Math.max(x, y) + 1); |
| } |
| |
| /** |
| * Returns a timestamped value. |
| * |
| * @param value the value to timestamp |
| * @param <T> the value type |
| * @return the timestamped value |
| */ |
| public <T> Timestamped<T> timestamp(T value) { |
| return new Timestamped<>(value, getTimestamp()); |
| } |
| |
| /** |
| * Increments and returns the current timestamp. |
| * |
| * @return the current timestamp |
| */ |
| public LogicalTimestamp getTimestamp() { |
| return new LogicalTimestamp(timestamp.incrementAndGet()); |
| } |
| } |