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Java > Open Source Codes > org > apache > derby > iapi > store > access > xa > XAXactId


1 /*
2
3    Derby - Class org.apache.derby.iapi.store.access.xa.XAXactId
4
5    Licensed to the Apache Software Foundation (ASF) under one or more
6    contributor license agreements. See the NOTICE file distributed with
7    this work for additional information regarding copyright ownership.
8    The ASF licenses this file to you under the Apache License, Version 2.0
9    (the "License"); you may not use this file except in compliance with
10    the License. You may obtain a copy of the License at
11
12       http://www.apache.org/licenses/LICENSE-2.0
13
14    Unless required by applicable law or agreed to in writing, software
15    distributed under the License is distributed on an "AS IS" BASIS,
16    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17    See the License for the specific language governing permissions and
18    limitations under the License.
19
20  */
21
22 package org.apache.derby.iapi.store.access.xa;
23
24 import org.apache.derby.iapi.services.sanity.SanityManager;
25
26 import org.apache.derby.iapi.store.access.GlobalXact;
27
28 import javax.transaction.xa.Xid JavaDoc;
29 import javax.transaction.xa.XAException JavaDoc;
30
31 /**
32
33 The XAXactId class is a specific implementation of the JTA Xid interface. It
34 is only used by the TransactionTable.restore() interface to return an array
35 of Xid's back to the caller, as part of serving the XAresource.restore()
36 interface.
37 <P>
38 It is NOT the object that is stored in the log. One reason for this is that
39 the Formattable and Xid interface's define two different return values for
40 the getFormatId() interface.
41
42 **/
43
44 public class XAXactId extends GlobalXact implements Xid JavaDoc
45 {
46     /**************************************************************************
47      * Private Fields of the class
48      **************************************************************************
49      */
50     private static final char COLON = ':';
51
52     /**************************************************************************
53      * Constructors for This class:
54      **************************************************************************
55      */
56
57     /**
58      * initialize by making array copies of appropriate fields.
59      * <p>
60      **/
61     private void copy_init_xid(
62                                int format_id,
63                                byte[] global_id,
64                                byte[] branch_id)
65     {
66         this.format_id = format_id;
67         this.global_id = new byte[global_id.length];
68         System.arraycopy(global_id, 0, this.global_id, 0, global_id.length);
69         this.branch_id = new byte[branch_id.length];
70         System.arraycopy(branch_id, 0, this.branch_id, 0, branch_id.length);
71     }
72     
73     /**
74      * Construct from given pieces of an Xid. Makes copies of arrays.
75      * <p>
76      **/
77     public XAXactId(
78                     int format_id,
79                     byte[] global_id,
80                     byte[] branch_id)
81     {
82         copy_init_xid(format_id, global_id, branch_id);
83     }
84
85     /**
86      * Construct an Xid using an external Xid.
87      * <p>
88      * @exception XAException invalid external xid
89      */
90     public XAXactId(Xid JavaDoc xid) throws XAException JavaDoc
91     {
92         if (xid == null)
93             throw new XAException JavaDoc(XAException.XAER_NOTA);
94     
95         copy_init_xid(
96                       xid.getFormatId(),
97                       xid.getGlobalTransactionId(),
98                       xid.getBranchQualifier());
99     }
100
101
102
103
104
105     public String JavaDoc toHexString()
106     {
107         // the ascii representation of xid where xid is of
108 // format_id = f
109 // global_id = byte[N]
110 // branch_id = byte[M]
111 //
112 // :xx:yy:ffffffff:n...n:mmmm...m:
113 // where xx = N (up to 64 max)
114 // yy = M (up to 64 max)
115 // n..n = hex dump of global_id (0 to 128 bytes max)
116 // m..m = hex dump of branch_qualifier (0 to 128 bytes max)
117
118     // 1+2+1+2+1+9+1+1+1
119 int maxLength = 20+(global_id.length+branch_id.length)*2;
120         
121         StringBuffer JavaDoc hexdump = new StringBuffer JavaDoc(maxLength);
122         hexdump.append(COLON).
123             append(Integer.toString(global_id.length)).append(COLON).
124             append(Integer.toString(branch_id.length)).append(COLON).
125             append(Integer.toString(format_id, 16)).append(COLON).
126             append(org.apache.derby.iapi.util.StringUtil.toHexString(global_id, 0, global_id.length)).append(COLON).
127             append(org.apache.derby.iapi.util.StringUtil.toHexString(branch_id, 0, branch_id.length)).append(COLON);
128     
129         return hexdump.toString();
130
131     }
132
133     public XAXactId(String JavaDoc xactIdString)
134     {
135         // extract it in pieces delimited by COLON
136 int start, end, length;
137     
138     // xx
139 start = 1;
140         end = xactIdString.indexOf(COLON, start);
141         if (SanityManager.DEBUG)
142             SanityManager.ASSERT(end != -1, "illegal string format");
143     
144         String JavaDoc xx = xactIdString.substring(start, end);
145         int N = Integer.parseInt(xx);
146     
147         if (SanityManager.DEBUG)
148         {
149             SanityManager.ASSERT(N > 0 && N <= Xid.MAXGTRIDSIZE, "illegal gtrid size");
150         }
151     
152     // yy
153 start = end+1; // skip the COLON
154 end = xactIdString.indexOf(COLON, start);
155         if (SanityManager.DEBUG)
156             SanityManager.ASSERT(end != -1, "illegal string format");
157     
158         String JavaDoc yy = xactIdString.substring(start,end);
159         int M = Integer.parseInt(yy);
160     
161         if (SanityManager.DEBUG)
162             SanityManager.ASSERT(M > 0 && N <= Xid.MAXBQUALSIZE, "illegal bqual size");
163     
164     // ffffffff
165 start = end+1; // skip the COLON
166 end = xactIdString.indexOf(COLON, start);
167         if (SanityManager.DEBUG)
168             SanityManager.ASSERT(end != -1, "illegal string format");
169     
170         String JavaDoc f = xactIdString.substring(start,end);
171         format_id = Integer.parseInt(f, 16);
172
173     // n...n
174 start = end+1; // skip the COLON
175 end = xactIdString.indexOf(COLON, start);
176         if (SanityManager.DEBUG)
177             SanityManager.ASSERT(end != -1, "illegal string format");
178     
179         global_id = org.apache.derby.iapi.util.StringUtil.fromHexString(xactIdString, start, (end-start));
180     
181         if (SanityManager.DEBUG)
182             SanityManager.ASSERT(global_id.length == N, "inconsistent global_id length");
183             
184     
185     // m...m
186 start = end+1; // skip the COLON
187 end = xactIdString.indexOf(COLON, start);
188         if (SanityManager.DEBUG)
189             SanityManager.ASSERT(end != -1, "illegal string format");
190     
191         branch_id = org.apache.derby.iapi.util.StringUtil.fromHexString(xactIdString, start, (end-start));
192     
193         if (SanityManager.DEBUG)
194             SanityManager.ASSERT(branch_id.length == M,
195                                  "inconsistent branch_id length, expect " + M + " got " +
196                                  branch_id.length);
197     
198     }
199
200
201
202     /**************************************************************************
203      * Private/Protected methods of This class:
204      **************************************************************************
205      */
206
207     /**************************************************************************
208      * Public Methods implementing the Xid interface:
209      **************************************************************************
210      */
211
212     /**
213      * Obtain the format id part of the Xid.
214      * <p>
215      *
216      * @return Format identifier. O means the OSI CCR format.
217      **/
218     public int getFormatId()
219     {
220         return(format_id);
221     }
222
223     /**
224      * Obtain the global transaction identifier part of XID as an array of
225      * bytes.
226      * <p>
227      *
228      * @return A byte array containing the global transaction identifier.
229      **/
230     public byte[] getGlobalTransactionId()
231     {
232         return(global_id);
233     }
234
235     /**
236      * Obtain the transaction branch qualifier part of the Xid in a byte array.
237      * <p>
238      *
239      * @return A byte array containing the branch qualifier of the transaction.
240      **/
241     public byte[] getBranchQualifier()
242     {
243         return(branch_id);
244     }
245
246
247
248     public boolean equals(Object JavaDoc other)
249     {
250         if (other == this)
251             return true;
252
253         if (other == null)
254             return false;
255     
256         try
257         {
258             if (other instanceof GlobalXact)
259                 return super.equals(other);
260             // Just cast it and catch the exception rather than doing the type
261 // checking twice.
262 Xid JavaDoc other_xid = (Xid JavaDoc) other;
263         
264             return(
265                    java.util.Arrays.equals(
266                                     other_xid.getGlobalTransactionId(),
267                                     this.global_id) &&
268                    java.util.Arrays.equals(
269                                     other_xid.getBranchQualifier(),
270                                     this.branch_id) &&
271                    other_xid.getFormatId() == this.format_id);
272         
273         }
274         catch(ClassCastException JavaDoc cce)
275         {
276             // this class only knows how to compare with other Xids
277 if (SanityManager.DEBUG)
278                 SanityManager.THROWASSERT("comparing XAXactId with " +
279                                           other.getClass().getName());
280         
281             return false;
282         }
283     }
284
285
286 }
287
288
289
290
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