| /** |
| * 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.distributedlog.util; |
| |
| import org.apache.distributedlog.DistributedLogConstants; |
| import org.apache.distributedlog.common.util.Sequencer; |
| |
| /** |
| * Time based sequencer. It generated non-decreasing transaction id using milliseconds. |
| * It isn't thread-safe. The caller takes the responsibility on synchronization. |
| */ |
| public class TimeSequencer implements Sequencer { |
| |
| private long lastId = DistributedLogConstants.INVALID_TXID; |
| |
| public void setLastId(long lastId) { |
| this.lastId = lastId; |
| } |
| |
| @Override |
| public long nextId() { |
| lastId = Math.max(lastId, System.currentTimeMillis()); |
| return lastId; |
| } |
| } |