1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 * 19 */ 20 package org.apache.directory.mitosis.common; 21 22 23 /** 24 * A default {@link CSNFactory} implementation. 25 * 26 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 27 */ 28 public class DefaultCSNFactory implements CSNFactory 29 { 30 private static int operationSequence; 31 32 33 public DefaultCSNFactory() 34 { 35 } 36 37 38 /** 39 * Returns a new {@link CSN}. 40 * Generated CSN can be duplicate if user generates CSNs more than 2G 41 * times a milliseconds. 42 * 43 * @param replicaId Replica ID. ReplicaID must be 1-8 digit alphanumeric 44 * string. 45 */ 46 public synchronized CSN newInstance( String replicaId ) 47 { 48 long newTimestamp = System.currentTimeMillis(); 49 50 if ( operationSequence == Integer.MAX_VALUE ) 51 { 52 // Roll over when reaching the limit. 53 operationSequence = 0; 54 } 55 56 CSN newCSN = new DefaultCSN( newTimestamp, replicaId, operationSequence++ ); 57 return newCSN; 58 } 59 }