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 }