1 /**
2 *
3 * Copyright 2003-2004 The Apache Software Foundation
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.geronimo.transaction.manager;
19
20 import javax.transaction.xa.Xid;
21 import java.net.InetAddress;
22 import java.net.UnknownHostException;
23
24 /**
25 * Factory for transaction ids.
26 * The Xid is constructed of three parts:
27 * <ol><li>8 byte count (LSB first)</li>
28 * <li>4 byte system id</li>
29 * <li>4 or 16 byte IP address of host</li>
30 * <ol>
31 * @version $Rev: 355877 $ $Date: 2005-12-10 18:48:27 -0800 (Sat, 10 Dec 2005) $
32 * todo Should have a way of setting baseId
33 */
34 public class XidFactoryImpl implements XidFactory {
35 private final byte[] baseId = new byte[Xid.MAXGTRIDSIZE];
36 private long count = 1;
37
38 public XidFactoryImpl(byte[] tmId) {
39 System.arraycopy(tmId, 0, baseId, 8, tmId.length);
40 }
41
42 public XidFactoryImpl() {
43 byte[] hostid;
44 try {
45 hostid = InetAddress.getLocalHost().getAddress();
46 } catch (UnknownHostException e) {
47 hostid = new byte[]{127, 0, 0, 1};
48 }
49 int uid = System.identityHashCode(this);
50 baseId[8] = (byte) uid;
51 baseId[9] = (byte) (uid >>> 8);
52 baseId[10] = (byte) (uid >>> 16);
53 baseId[11] = (byte) (uid >>> 24);
54 System.arraycopy(hostid, 0, baseId, 12, hostid.length);
55 }
56
57 public Xid createXid() {
58 byte[] globalId = (byte[]) baseId.clone();
59 long id;
60 synchronized (this) {
61 id = count++;
62 }
63 globalId[0] = (byte) id;
64 globalId[1] = (byte) (id >>> 8);
65 globalId[2] = (byte) (id >>> 16);
66 globalId[3] = (byte) (id >>> 24);
67 globalId[4] = (byte) (id >>> 32);
68 globalId[5] = (byte) (id >>> 40);
69 globalId[6] = (byte) (id >>> 48);
70 globalId[7] = (byte) (id >>> 56);
71 return new XidImpl(globalId);
72 }
73
74 public Xid createBranch(Xid globalId, int branch) {
75 byte[] branchId = (byte[]) baseId.clone();
76 branchId[0] = (byte) branch;
77 branchId[1] = (byte) (branch >>> 8);
78 branchId[2] = (byte) (branch >>> 16);
79 branchId[3] = (byte) (branch >>> 24);
80 return new XidImpl(globalId, branchId);
81 }
82
83 public boolean matchesGlobalId(byte[] globalTransactionId) {
84 if (globalTransactionId.length != Xid.MAXGTRIDSIZE) {
85 return false;
86 }
87 for (int i = 8; i < globalTransactionId.length; i++) {
88 if (globalTransactionId[i] != baseId[i]) {
89 return false;
90 }
91 }
92 return true;
93 }
94
95 public boolean matchesBranchId(byte[] branchQualifier) {
96 if (branchQualifier.length != Xid.MAXBQUALSIZE) {
97 return false;
98 }
99 for (int i = 8; i < branchQualifier.length; i++) {
100 if (branchQualifier[i] != baseId[i]) {
101 return false;
102 }
103 }
104 return true;
105 }
106
107 public Xid recover(int formatId, byte[] globalTransactionid, byte[] branchQualifier) {
108 return new XidImpl(formatId, globalTransactionid, branchQualifier);
109 }
110
111 }