AbstractSimpleService


1   /*
2    * $Header: /home/cvs/jakarta-slide/src/share/org/apache/slide/common/AbstractSimpleService.java,v 1.9 2004/07/28 09:38:22 ib Exp $
3    * $Revision: 1.9 $
4    * $Date: 2004/07/28 09:38:22 $
5    *
6    * ====================================================================
7    *
8    * Copyright 1999-2002 The Apache Software Foundation 
9    *
10   * Licensed under the Apache License, Version 2.0 (the "License");
11   * you may not use this file except in compliance with the License.
12   * You may obtain a copy of the License at
13   *
14   *     http://www.apache.org/licenses/LICENSE-2.0
15   *
16   * Unless required by applicable law or agreed to in writing, software
17   * distributed under the License is distributed on an "AS IS" BASIS,
18   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19   * See the License for the specific language governing permissions and
20   * limitations under the License.
21   *
22   */
23  
24  package org.apache.slide.common;
25  
26  import java.util.Vector  ;
27  
28  import javax.transaction.xa.XAException  ;
29  import javax.transaction.xa.XAResource  ;
30  import javax.transaction.xa.Xid  ;
31  
32  import org.apache.slide.transaction.SlideTransactionManager;
33  
34  /**
35   * Slide Service simple implementation. Will allow only one simultaneous
36   * transaction context.
37   *
38   * @deprecated do not use as it only allows for a single concurrent transaction context
39   * @version $Revision: 1.9 $
40   */
41  public abstract class AbstractSimpleService extends AbstractServiceBase
42      implements Service {
43      
44      
45      // -------------------------------------------------------------- Constants
46      
47      
48      public static final int TX_IDLE = 0;
49      public static final int TX_PREPARED = 1;
50      public static final int TX_SUSPENDED = 2;
51      
52      
53      // ----------------------------------------------------- Instance Variables
54      
55      
56      /**
57       * Current transaction context.
58       */
59      protected Xid   currentContext = null;
60      
61      
62      /**
63       * Status reagrding the current job.
64       */
65      protected int status = TX_IDLE;
66      
67      
68      /**
69       * Transaction timeout.
70       */
71      protected int transactionTimeout =
72          SlideTransactionManager.DEFAULT_TRANSACTION_TIMEOUT;
73      
74      
75      /**
76       * Rollback only.
77       */
78      protected boolean rollbackOnly = false;
79      
80      
81      // ----------------------------------------------------- XAResource Mathods
82      
83      
84      /**
85       * Commit the global transaction specified by xid.
86       *
87       * @param xid A global transaction identifier
88       * @param onePhase If true, the resource manager should use a one-phase
89       * commit protocol to commit the work done on behalf of xid.
90       * @exception XAException An error has occurred. Possible XAExceptions
91       * are XA_HEURHAZ, XA_HEURCOM, XA_HEURRB, XA_HEURMIX, XAER_RMERR,
92       * XAER_RMFAIL, XAER_NOTA, XAER_INVAL, or XAER_PROTO. If the resource
93       * manager did not commit the transaction and the paramether onePhase is
94       * set to true, the resource manager may throw one of the XA_RB*
95       * exceptions. Upon return, the resource manager has rolled back the
96       * branch's work and has released all held resources.
97       */
98      public void commit(Xid   xid, boolean onePhase)
99          throws XAException   {
100         
101         if (currentContext == null)
102             throw new XAException  (XAException.XAER_NOTA);
103     if (xid == null)
104         throw new XAException  (XAException.XAER_INVAL);
105         if (currentContext.getGlobalTransactionId()
106             != xid.getGlobalTransactionId())
107             throw new XAException  (XAException.XAER_PROTO);
108         
109         if (!onePhase && status != TX_PREPARED)
110             throw new XAException  (XAException.XAER_PROTO);
111         if (onePhase && (!((status == TX_IDLE) || (status == TX_SUSPENDED))))
112             throw new XAException  (XAException.XAER_PROTO);
113         
114         if (rollbackOnly) {
115             rollback(xid);
116             throw new XAException  (XAException.XA_RBROLLBACK);
117         }
118         
119         currentContext = null;
120         status = TX_IDLE;
121         rollbackOnly = false;
122         
123     }
124     
125     
126     /**
127      * Ends the work performed on behalf of a transaction branch. The
128      * resource manager disassociates the XA resource from the transaction
129      * branch specified and let the transaction be completed.
130      * If TMSUSPEND is specified in flags, the transaction branch is
131      * temporarily suspended in incomplete state. The transaction context is
132      * in suspened state and must be resumed via start with TMRESUME specified.
133      * If TMFAIL is specified, the portion of work has failed. The resource
134      * manager may mark the transaction as rollback-only.
135      * If TMSUCCESS is specified, the portion of work has completed
136      * successfully.
137      *
138      * @param xid A global transaction identifier that is the same as what
139      * was used previously in the start method.
140      * @param flags One of TMSUCCESS, TMFAIL, or TMSUSPEND
141      * @exception XAException An error has occurred. Possible XAException
142      * values are XAER_RMERR, XAER_RMFAILED, XAER_NOTA, XAER_INVAL,
143      * XAER_PROTO, or XA_RB*.
144      */
145     public void end(Xid   xid, int flags)
146         throws XAException   {
147         
148         if (currentContext == null)
149             throw new XAException  (XAException.XAER_NOTA);
150     if (xid == null)
151         throw new XAException  (XAException.XAER_INVAL);
152         if (currentContext.getGlobalTransactionId()
153             != xid.getGlobalTransactionId())
154             throw new XAException  (XAException.XAER_PROTO);
155         
156         if (flags == XAResource.TMSUSPEND)
157             status = TX_SUSPENDED;
158         
159         if (flags == XAResource.TMFAIL)
160             rollbackOnly = true;
161         
162     }
163     
164     
165     /**
166      * Tell the resource manager to forget about a heuristically completed
167      * transaction branch.
168      *
169      * @param xid A global transaction identifier
170      * @exception XAException An error has occurred. Possible exception values
171      * are XAER_RMERR, XAER_RMFAIL, XAER_NOTA, XAER_INVAL, or XAER_PROTO.
172      */
173     public void forget(Xid   xid)
174         throws XAException   {
175         
176         if (currentContext == null)
177             throw new XAException  (XAException.XAER_NOTA);
178     if (xid == null)
179         throw new XAException  (XAException.XAER_INVAL);
180         if (currentContext.getGlobalTransactionId()
181             != xid.getGlobalTransactionId())
182             throw new XAException  (XAException.XAER_PROTO);
183         
184         currentContext = null;
185         status = TX_IDLE;
186         rollbackOnly = false;
187         
188     }
189     
190     
191     /**
192      * Obtain the current transaction timeout value set for this XAResource
193      * instance. If XAResource.setTransactionTimeout was not use prior to
194      * invoking this method, the return value is the default timeout set for
195      * the resource manager; otherwise, the value used in the previous
196      * setTransactionTimeout call is returned.
197      *
198      * @return the transaction timeout value in seconds.
199      * @exception XAException An error has occurred. Possible exception
200      * values are XAER_RMERR, XAER_RMFAIL.
201      */
202     public int getTransactionTimeout()
203         throws XAException   {
204         
205         return transactionTimeout;
206         
207     }
208     
209     
210     /**
211      * This method is called to determine if the resource manager instance
212      * represented by the target object is the same as the resouce manager
213      * instance represented by the parameter xares.
214      *
215      * @param xares An XAResource object whose resource manager instance is
216      * to be compared with the resource manager instance of the target object.
217      * @return true if it's the same RM instance; otherwise false.
218      * @exception XAException An error has occurred. Possible exception values
219      * are XAER_RMERR, XAER_RMFAIL.
220      */
221     public boolean isSameRM(XAResource   xares)
222         throws XAException   {
223         
224         if (xares == null)
225             return false;
226         
227         return (this == xares);
228         
229     }
230     
231     
232     /**
233      * Ask the resource manager to prepare for a transaction commit of the
234      * transaction specified in xid.
235      *
236      * @param xid A global transaction identifier
237      * @return A value indicating the resource manager's vote on the outcome
238      * of the transaction. The possible values are: XA_RDONLY or XA_OK. If
239      * the resource manager wants to roll back the transaction, it should do
240      * so by raising an appropriate XAException in the prepare method.
241      * @exception XAException An error has occurred. Possible exception
242      * values are: XA_RB*, XAER_RMERR, XAER_RMFAIL, XAER_NOTA, XAER_INVAL,
243      * or XAER_PROTO.
244      */
245     public int prepare(Xid   xid)
246         throws XAException   {
247         
248         if (currentContext == null)
249             throw new XAException  (XAException.XAER_NOTA);
250     if (xid == null)
251         throw new XAException  (XAException.XAER_INVAL);
252         if (currentContext.getGlobalTransactionId()
253             != xid.getGlobalTransactionId())
254             throw new XAException  (XAException.XAER_PROTO);
255         
256         if (!((status == TX_IDLE) || (status == TX_SUSPENDED)))
257             throw new XAException  (XAException.XAER_PROTO);
258         
259         if (rollbackOnly) {
260             // FIXME: Don't know if should be automatically rollbacked in that
261             // case
262             throw new XAException  (XAException.XA_RBROLLBACK);
263         }
264         
265         status = TX_PREPARED;
266         
267         return XAResource.XA_OK;
268         
269     }
270     
271     
272     /**
273      * Obtain a list of prepared transaction branches from a resource manager.
274      * The transaction manager calls this method during recovery to obtain the
275      * list of transaction branches that are currently in prepared or
276      * heuristically completed states.
277      *
278      * @param flag One of TMSTARTRSCAN, TMENDRSCAN, TMNOFLAGS. TMNOFLAGS must
279      * be used when no other flags are set in flags.
280      * @return The resource manager returns zero or more XIDs for the
281      * transaction branches that are currently in a prepared or heuristically
282      * completed state. If an error occurs during the operation, the resource
283      * manager should throw the appropriate XAException.
284      * @exception XAException An error has occurred. Possible values are
285      * XAER_RMERR, XAER_RMFAIL, XAER_INVAL, and XAER_PROTO.
286      */
287     public Xid  [] recover(int flag)
288         throws XAException   {
289         
290         Vector   list = new Vector  ();
291         
292         if ((status == TX_PREPARED) && (currentContext != null))
293            list.addElement(currentContext);
294         
295         return (Xid  []) list.toArray(new Xid  [list.size()]);
296         
297     }
298     
299     
300     /**
301      * Inform the resource manager to roll back work done on behalf of a
302      * transaction branch.
303      *
304      * @param xid A global transaction identifier
305      * @exception XAException An error has occurred
306      */
307     public void rollback(Xid   xid)
308         throws XAException   {
309         
310         if (currentContext == null)
311             throw new XAException  (XAException.XAER_NOTA);
312     if (xid == null)
313         throw new XAException  (XAException.XAER_INVAL);
314         if (currentContext.getGlobalTransactionId()
315             != xid.getGlobalTransactionId())
316             throw new XAException  (XAException.XAER_PROTO);
317         
318         status = TX_IDLE;
319         currentContext = null;
320         rollbackOnly = false;
321         
322     }
323     
324     
325     /**
326      * Set the current transaction timeout value for this XAResource instance.
327      *
328      * @param seconds the transaction timeout value in seconds.
329      * @return true if transaction timeout value is set successfully;
330      * otherwise false.
331      * @exception XAException An error has occurred. Possible exception
332      * values are XAER_RMERR, XAER_RMFAIL, or XAER_INVAL.
333      */
334     public boolean setTransactionTimeout(int seconds)
335         throws XAException   {
336         transactionTimeout = seconds;
337         return true;
338     }
339     
340     
341     /**
342      * Start work on behalf of a transaction branch specified in xid If
343      * TMJOIN is specified, the start is for joining a transaction previously
344      * seen by the resource manager. If TMRESUME is specified, the start is
345      * to resume a suspended transaction specified in the parameter xid. If
346      * neither TMJOIN nor TMRESUME is specified and the transaction specified
347      * by xid has previously been seen by the resource manager, the resource
348      * manager throws the XAException exception with XAER_DUPID error code.
349      *
350      * @param xid A global transaction identifier to be associated with the
351      * resource
352      * @param flags One of TMNOFLAGS, TMJOIN, or TMRESUME
353      * @exception XAException An error has occurred. Possible exceptions are
354      * XA_RB*, XAER_RMERR, XAER_RMFAIL, XAER_DUPID, XAER_OUTSIDE, XAER_NOTA,
355      * XAER_INVAL, or XAER_PROTO.
356      */
357     public void start(Xid   xid, int flags)
358         throws XAException   {
359         
360     if (xid == null)
361         throw new XAException  (XAException.XAER_INVAL);
362         if ( (currentContext != null) &&
363              (currentContext.getGlobalTransactionId()
364               != xid.getGlobalTransactionId()) )
365             throw new XAException  (XAException.XAER_OUTSIDE);
366         
367         switch (flags) {
368         case XAResource.TMNOFLAGS:
369             if (currentContext != null)
370                 throw new XAException  (XAException.XAER_INVAL);
371             currentContext = xid;
372             break;
373         case XAResource.TMJOIN:
374             if (currentContext == null)
375                 throw new XAException  (XAException.XAER_NOTA);
376             if (currentContext.getGlobalTransactionId()
377                 != xid.getGlobalTransactionId())
378                 throw new XAException  (XAException.XAER_INVAL);
379             break;
380         case XAResource.TMRESUME:
381             if (currentContext == null)
382                 throw new XAException  (XAException.XAER_NOTA);
383             if (status != TX_SUSPENDED)
384                 throw new XAException  (XAException.XAER_INVAL);
385             status = TX_IDLE;
386             break;
387         }
388         
389     }
390     
391     
392 }
393 
394
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