NamingContextImpl


1   package org.jacorb.naming;
2   
3   /*
4    *        JacORB - a free Java ORB
5    *
6    *   Copyright (C) 1997-2004 Gerald Brose.
7    *
8    *   This library is free software; you can redistribute it and/or
9    *   modify it under the terms of the GNU Library General Public
10   *   License as published by the Free Software Foundation; either
11   *   version 2 of the License, or (at your option) any later version.
12   *
13   *   This library is distributed in the hope that it will be useful,
14   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16   *   Library General Public License for more details.
17   *
18   *   You should have received a copy of the GNU Library General Public
19   *   License along with this library; if not, write to the Free
20   *   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21   */
22  
23  import java.net.*;
24  import java.util.*;
25  import java.io.*;
26  
27  import org.omg.CosNaming.*;
28  import org.omg.CosNaming.NamingContextPackage.*;
29  import org.omg.CosNaming.NamingContextExtPackage.*;
30  
31  import org.apache.avalon.framework.logger.Logger;
32  import org.apache.avalon.framework.configuration.*;
33  
34  /**
35   *      The implementation for the CORBAService Naming
36   *
37   *      @author Gerald Brose
38   *      @version $Id: NamingContextImpl.java,v 1.26 2005/06/01 10:03:50 andre.spiegel Exp $
39   */
40  
41  public class NamingContextImpl
42      extends NamingContextExtPOA
43      implements java.io.Serializable  , Configurable
44  {
45      /** table of all name bindings in this contexts, ie. name -> obj ref. */
46      private Hashtable names = new Hashtable();
47  
48      /** table of all subordinate naming contexts, ie. name -> obj ref. */
49      private Hashtable contexts = new Hashtable();
50  
51      /** configuration */
52      private org.jacorb.config.Configuration configuration = null;
53  
54      /** no tests of bound objects for existence */
55      private boolean noPing = false;
56  
57      /** purge? */
58      private boolean doPurge = false;
59  
60      /** the logger used by the naming service implementation */
61      private static Logger logger = null;
62  
63      /** the POAs used */
64      transient private org.omg.PortableServer.POA   poa;
65      private static org.omg.PortableServer.POA   rootPoa;
66      private static org.omg.CORBA.ORB   orb;
67  
68      private int child_count;
69      private boolean destroyed = false;
70  
71  
72      public void configure(Configuration myConfiguration)
73          throws ConfigurationException
74      {
75          this.configuration = (org.jacorb.config.Configuration)myConfiguration;
76          logger = configuration.getNamedLogger("jacorb.naming");
77          doPurge = configuration.getAttribute("jacorb.naming.purge","off").equals("on");
78          noPing = configuration.getAttribute("jacorb.naming.noping","off").equals("on");
79      }
80  
81  
82      /**
83       *  bind a name (an array of name components) to an object
84       */
85  
86      public void bind( NameComponent[] nc, org.omg.CORBA.Object   obj)
87          throws NotFound, CannotProceed, InvalidName, AlreadyBound
88      {
89          if( destroyed )
90              throw new CannotProceed();
91  
92          if( nc == null || nc.length == 0 )
93              throw new InvalidName();
94  
95          if( obj == null )
96              throw new org.omg.CORBA.BAD_PARAM  ();
97  
98          Name n = new Name( nc );
99          Name ctx = n.ctxName();
100         NameComponent nb = n.baseNameComponent();
101         if( ctx == null )
102         {
103             if( names.containsKey( n ))
104             {
105                 // if the name is still in use, try to ping the object
106                 org.omg.CORBA.Object   s = (org.omg.CORBA.Object  )names.get(n);
107                 if( isDead(s) )
108                 {
109                     rebind( n.components(), obj );
110                     return;
111                 }
112                 throw new AlreadyBound();
113             }
114             else if( contexts.containsKey( n ))
115             {
116                 // if the name is still in use, try to ping the object
117                 org.omg.CORBA.Object   s = (org.omg.CORBA.Object  )contexts.get(n);
118                 if( isDead(s) )
119                 {
120                     unbind( n.components());
121                 }
122                 throw new AlreadyBound();
123             }
124 
125             if(( names.put( n, obj )) != null )
126                 throw new CannotProceed( _this(), n.components() );
127 
128             if( logger.isInfoEnabled() )
129             {
130                 logger.info("Bound name: " + n.toString());
131             }
132         }
133         else
134         {
135             NameComponent[] ncx = new NameComponent[1];
136             ncx[0] = nb;
137             NamingContextExtHelper.narrow(resolve(ctx.components())).bind(ncx,obj);
138         }
139     }
140 
141 
142     /**
143      * Bind an object to a name that's already in use, i.e. rebind the name
144      */
145 
146     public void rebind(NameComponent[] nc, org.omg.CORBA.Object   obj)
147         throws NotFound, CannotProceed, InvalidName
148     {
149         if( destroyed )
150             throw new CannotProceed();
151 
152         if( nc == null || nc.length == 0 )
153             throw new InvalidName();
154 
155         if( obj == null )
156             throw new org.omg.CORBA.BAD_PARAM  ();
157 
158         Name n = new Name( nc );
159         Name ctx = n.ctxName();
160         NameComponent nb = n.baseNameComponent();
161 
162         // the name is bound, but it is bound to a context,
163         // the client should have been using rebind_context!
164 
165         if( contexts.containsKey( n ))
166             throw new NotFound(NotFoundReason.not_object, new NameComponent[]{ nb } );
167 
168         // try remove an existing binding
169 
170         org.omg.CORBA.Object   _o = (org.omg.CORBA.Object  )names.remove( n );
171         if( _o != null)
172             _o._release();
173 
174         if( ctx == null )
175         {
176             // do the rebinding in this context
177 
178             names.put( n, obj );
179             if( logger.isInfoEnabled() )
180             {
181                 logger.info("re-Bound name: " + n.toString());
182             }
183         }
184         else
185         {
186             // rebind in the correct context
187 
188             NameComponent[] ncx = new NameComponent[1];
189             ncx[0] = nb;
190             NamingContextExt nce = NamingContextExtHelper.narrow(resolve(ctx.components()));
191             if( nce == null )
192                 throw new CannotProceed();
193             nce.rebind(ncx,obj);
194         }
195     }
196 
197 
198     /**
199      * Bind an context to a name that's already in use, i.e. rebind the name
200      */
201 
202     public void rebind_context(NameComponent[] nc, NamingContext obj)
203         throws NotFound, CannotProceed, InvalidName
204     {
205         if( destroyed )
206             throw new CannotProceed();
207 
208         if( nc == null || nc.length == 0 )
209             throw new InvalidName();
210 
211         if( obj == null )
212             throw new org.omg.CORBA.BAD_PARAM  ();
213 
214         Name n = new Name( nc );
215         Name ctx = n.ctxName();
216         NameComponent nb = n.baseNameComponent();
217 
218         // the name is bound, but it is bound to an object,
219         // the client should have been using rebind() !
220 
221         if( names.containsKey( n ))
222             throw new NotFound(NotFoundReason.not_context,new NameComponent[]{ nb });
223 
224         // try to remove an existing context binding
225 
226         org.omg.CORBA.Object   _o = (org.omg.CORBA.Object  )contexts.remove( n );
227         if( _o != null)
228             _o._release();
229 
230         if( ctx == null )
231         {
232             contexts.put( n, obj );
233             if (logger.isInfoEnabled())
234             {
235                 logger.info("Re-Bound context: " +
236                             n.baseNameComponent().id);
237             }
238         }
239     }
240 
241 
242 
243     /**
244      * Bind a context to a name
245      */
246 
247     public void bind_context(NameComponent[] nc,
248                              NamingContext obj)
249         throws NotFound, CannotProceed, InvalidName, AlreadyBound
250     {
251         if( destroyed )
252             throw new CannotProceed();
253 
254         Name n = new Name( nc );
255         Name ctx = n.ctxName();
256         NameComponent nb = n.baseNameComponent();
257 
258         if( ctx == null )
259         {
260             if( names.containsKey( n ))
261             {
262                 // if the name is still in use, try to ping the object
263                 org.omg.CORBA.Object   s = (org.omg.CORBA.Object  )names.get(n);
264                 if( isDead(s) )
265                 {
266                     unbind( n.components());
267                 }
268                 else
269                     throw new AlreadyBound();
270             }
271             else if( contexts.containsKey( n ))
272             {
273                 // if the name is still in use, try to ping the object
274                 org.omg.CORBA.Object   s = (org.omg.CORBA.Object  )contexts.get(n);
275                 if( isDead(s) )
276                 {
277                     rebind_context( n.components(), obj );
278                     return;
279                 }
280                 throw new AlreadyBound();
281             }
282 
283             if( (contexts.put( n, obj )) != null )
284                 throw new CannotProceed( _this(), n.components());
285             contexts.put( n, obj );
286 
287             if (logger.isInfoEnabled())
288             {
289                 logger.info("Bound context: " + n.toString());
290             }
291         }
292         else
293         {
294             NameComponent[] ncx = new NameComponent[1];
295             ncx[0] = nb;
296             NamingContextExtHelper.narrow(resolve(ctx.components())).bind_context(ncx,obj);
297         }
298     }
299 
300     public NamingContext bind_new_context(NameComponent[] nc )
301         throws NotFound, CannotProceed, InvalidName, AlreadyBound
302     {
303         if( destroyed )
304             throw new CannotProceed();
305 
306         if( nc == null || nc.length == 0 )
307             throw new InvalidName();
308 
309         NamingContextExt ns = NamingContextExtHelper.narrow(new_context());
310         bind_context( nc, ns );
311 
312         if( ns == null )
313         {
314             throw new CannotProceed();
315         }
316         return ns;
317     }
318 
319     /**
320      *  cleanup bindings, i.e. ping every object and remove bindings to
321      *  non-existent objects
322      */
323 
324     private void cleanup ()
325     {
326         // Check if object purging enabled
327 
328         if (! doPurge) 
329         {
330            return;
331         }
332 
333         Vector deletionVector = new Vector();
334 
335         for( Enumeration n = names.keys(); n.hasMoreElements(); )
336         {
337             Name _n = (Name)n.nextElement();
338 
339             if( isDead(((org.omg.CORBA.Object  )names.get( _n ))) )
340             {
341                 if (logger.isInfoEnabled())
342                 {
343                     logger.info("Removing name " + _n.baseNameComponent().id);
344                 }
345                 deletionVector.addElement( _n );
346             }
347         }
348 
349         if( deletionVector.size() > 0 )
350         {
351             for( int i = deletionVector.size(); i-- > 0; )
352                 names.remove( (Name)deletionVector.elementAt(i));
353             deletionVector.removeAllElements();
354         }
355 
356         /* ping contexts */
357 
358         for( Enumeration c = contexts.keys(); c.hasMoreElements(); )
359         {
360             Name _n = (Name)c.nextElement();
361             if( isDead(((org.omg.CORBA.Object  )contexts.get( _n ))) )
362             {
363                 if (logger.isInfoEnabled())
364                 {
365                     logger.info("Removing context " + _n.baseNameComponent().id);
366                 }
367                 deletionVector.addElement( _n );
368             }
369         }
370 
371         if( deletionVector.size() > 0 )
372         {
373             for( int i = deletionVector.size(); i-- > 0; )
374                 contexts.remove( (Name)deletionVector.elementAt(i));
375             deletionVector.removeAllElements();
376         }
377     }
378 
379     public void destroy()
380         throws NotEmpty
381     {
382         if( destroyed )
383             return;
384 
385         if(!names.isEmpty() || !contexts.isEmpty() )
386             throw new NotEmpty();
387         else
388         {
389             names = null;
390             contexts = null;
391             destroyed = true;
392         }
393     }
394 
395     /**
396      *  @return numer of bindings in this context
397      */
398 
399     public int how_many()
400     {
401         if( destroyed )
402             return 0;
403         return names.size() + contexts.size();
404     }
405 
406 
407 
408     /**
409      *  list all bindings
410      */
411 
412     private Binding[] list()
413     {
414         Binding[] result;
415         cleanup();
416 
417         int how_many = how_many();
418 
419         Enumeration n = names.keys();
420         Enumeration c = contexts.keys();
421 
422         result = new Binding[how_many];
423         for( ; n.hasMoreElements() && how_many > 0; how_many-- )
424         {
425             result[how_many-1] =
426                 new Binding(((Name)n.nextElement()).components(),
427                             BindingType.nobject );
428         }
429 
430         for( ; c.hasMoreElements() && how_many > 0; how_many-- )
431         {
432             result[how_many-1] =
433                 new Binding(((Name)c.nextElement()).components(),
434                             BindingType.ncontext);
435         }
436 
437         return result;
438     }
439 
440     /**
441      *  list all bindings
442      */
443 
444     public void list(int how_many, BindingListHolder bl, BindingIteratorHolder  bi)
445     {
446         if( destroyed )
447             return;
448 
449         Binding[] result;
450 
451         cleanup();
452 
453         int size = how_many();
454 
455         Enumeration n = names.keys();
456         Enumeration c = contexts.keys();
457 
458         if( how_many < size )
459         {
460             // counter for copies
461             int how_many_ctr = how_many;
462 
463             // set up an array with "how_many" bindings
464 
465             result = new Binding[how_many];
466             for( ; n.hasMoreElements() && how_many_ctr > 0; how_many_ctr-- )
467             {
468                 result[how_many_ctr-1] = new Binding(((Name)n.nextElement()).components(),
469                                                  BindingType.nobject );
470             }
471 
472             for( ; c.hasMoreElements() && how_many_ctr > 0; how_many_ctr-- )
473             {
474                 result[how_many_ctr-1] = new Binding(((Name)c.nextElement()).components(),
475                                                  BindingType.ncontext);
476             }
477 
478             // create a new BindingIterator for the remaining arrays
479 
480             size -= how_many;
481             Binding[] rest = new Binding[ size ];
482             for( ; n.hasMoreElements() && size > 0; size-- )
483             {
484                 rest[size-1] = new Binding(((Name)n.nextElement()).components(),
485                                            BindingType.nobject );
486             }
487 
488             for( ; c.hasMoreElements() && size > 0; size-- )
489             {
490                 rest[size-1] = new Binding(((Name)c.nextElement()).components(),
491                                            BindingType.ncontext);
492             }
493 
494             org.omg.CORBA.Object   o = null;
495             try
496             {
497                 // Iterators are activated with the RootPOA (transient)
498                 byte[] oid = rootPoa.activate_object( new BindingIteratorImpl( rest ) );
499                 o = rootPoa.id_to_reference(oid);
500             }
501             catch ( Exception   ue )
502             {
503                 ue.printStackTrace();
504             }
505 
506             bi.value = BindingIteratorHelper.narrow(o);
507         }
508         else
509         {
510             result = new Binding[size];
511             for( ; n.hasMoreElements() && size > 0; size-- )
512             {
513                 result[size-1] =
514                     new Binding(((Name)n.nextElement()).components(),
515                                 BindingType.nobject );
516             }
517 
518             for( ; c.hasMoreElements() && size > 0; size-- )
519             {
520                 result[size-1] =
521                     new Binding(((Name)c.nextElement()).components(),
522                                 BindingType.ncontext);
523             }
524         }
525 
526         bl.value = result;
527     }
528 
529     public NamingContext new_context()
530     {
531         if( destroyed )
532             return null;
533 
534         org.omg.CORBA.Object   ctx = null;
535         try
536         {
537             byte[] oid = (new String  (poa.servant_to_id(this)) +
538                           "_ctx" + (++child_count)).getBytes();
539 
540             ctx = poa.create_reference_with_id( oid, "IDL:omg.org/CosNaming/NamingContextExt:1.0");
541             if (logger.isInfoEnabled())
542             {
543                 logger.info("New context.");
544             }
545         }
546         catch ( Exception   ue )
547         {
548             if (logger.isErrorEnabled())
549             {
550                 logger.error ("failed to create new context", ue);
551             }
552             throw new RuntimeException   ("failed to create new context: " 
553                                         + ue.toString());
554         }
555         return NamingContextExtHelper.narrow(ctx);
556     }
557 
558 
559 
560     /**
561      * resolve a name
562      */
563 
564     public org.omg.CORBA.Object   resolve(NameComponent[] nc)
565         throws NotFound, CannotProceed, InvalidName
566     {
567         if( destroyed )
568             throw new CannotProceed();
569 
570         if( nc == null || nc.length == 0 )
571             throw new InvalidName();
572 
573         Name n = new Name( nc[0] );
574         if( nc.length > 1 )
575         {
576             NamingContextExt next_context =
577                 NamingContextExtHelper.narrow((org.omg.CORBA.Object  )contexts.get(n));
578 
579 
580             if ((next_context == null)||(isDead(next_context)))
581             {
582                 throw new NotFound(NotFoundReason.missing_node,nc);
583             }
584 
585             NameComponent[] nc_prime =
586                 new NameComponent[nc.length-1];
587 
588             for( int i = 1; i < nc.length; i++)
589                 nc_prime[i-1] = nc[i];
590 
591             return next_context.resolve(nc_prime);
592         }
593         else
594         {
595             org.omg.CORBA.Object   result = null;
596 
597             result = (org.omg.CORBA.Object  )contexts.get(n);
598 
599             if( result == null )
600                 result = (org.omg.CORBA.Object  )names.get(n);
601 
602             if (result == null)
603                 throw new NotFound(NotFoundReason.missing_node, n.components());
604             
605             if ( !noPing && isDead(result))
606             {
607                 throw new NotFound(NotFoundReason.missing_node, n.components());
608             }
609 
610             return result;
611         }
612     }
613 
614     /**
615      * unbind a name
616      */
617 
618     public void unbind(NameComponent[] nc )
619         throws NotFound, CannotProceed, InvalidName
620     {
621         if( destroyed )
622             throw new CannotProceed();
623 
624         if( nc == null || nc.length == 0 )
625             throw new InvalidName();
626 
627         Name n = new Name( nc );
628         Name ctx = n.ctxName();
629         NameComponent nb = n.baseNameComponent();
630 
631         if( ctx == null )
632         {
633             if( names.containsKey(n))
634             {
635                 org.omg.CORBA.Object   o = (org.omg.CORBA.Object  )names.remove( n );
636                 o._release();
637                 if (logger.isInfoEnabled())
638                 {
639                     logger.info("Unbound: " + n.toString());
640                 }
641             }
642             else if( contexts.containsKey(n))
643             {
644                 org.omg.CORBA.Object   o = (org.omg.CORBA.Object  )contexts.remove( n );
645                 o._release();
646 
647                 if (logger.isInfoEnabled())
648                 {
649                     logger.info("Unbound: " + n.toString());
650                 }
651             }
652             else
653             {
654                 if (logger.isWarnEnabled())
655                 {
656                     logger.warn("Unbind failed for " + n.toString() );
657                 }
658                 throw new NotFound(NotFoundReason.not_context,
659                                    n.components());
660             }
661         }
662         else
663         {
664             NameComponent[] ncx = new NameComponent[1];
665             ncx[0] = nb;
666             NamingContextExtHelper.narrow( resolve( ctx.components())).unbind(ncx );
667         }
668     }
669 
670     /**
671      * POA-related,
672      */
673 
674     public org.omg.PortableServer.POA   default_POA()
675     {
676         return poa;
677     }
678 
679 
680     /**
681      * Overrides writeObject in Serializable
682      */
683 
684     private void writeObject(java.io.ObjectOutputStream   out)
685         throws IOException
686     {
687         /*
688          * For serialization, object references are transformed
689          * into strings
690          */
691 
692         for( Enumeration e = contexts.keys(); e.hasMoreElements();)
693         {
694             Name key = (Name)e.nextElement();
695             org.omg.CORBA.Object   o = (org.omg.CORBA.Object  )contexts.remove( key );
696             contexts.put( key, orb.object_to_string( o ));
697         }
698 
699         for( Enumeration e = names.keys(); e.hasMoreElements();)
700         {
701             Name key = (Name)e.nextElement();
702             org.omg.CORBA.Object   o = (org.omg.CORBA.Object  )names.remove(key);
703             names.put( key, orb.object_to_string( o ));
704         }
705 
706         out.defaultWriteObject();
707     }
708 
709     /**
710      *   This method needs to be called once to initialize
711      *   the static fields orb and rootPoa.
712      *
713      */
714 
715     public static void init(org.omg.CORBA.ORB   orb,
716                             org.omg.PortableServer.POA   rootPoa)
717     {
718         NamingContextImpl.orb = orb;
719         NamingContextImpl.rootPoa = rootPoa;
720     }
721 
722     /**
723      *   This method needs to be called for each newly created
724      *   or re-read naming context to set its poa.
725      *
726      */
727 
728     void init(org.omg.PortableServer.POA   poa)
729     {
730         this.poa = poa;
731 
732         /**
733          * Recreate tables. For serialization, object references
734          * have been transformed into strings
735          */
736 
737         for( Enumeration e = contexts.keys(); e.hasMoreElements();)
738         {
739             Name key = (Name)e.nextElement();
740             String   ref = (String  )contexts.remove(key);
741             contexts.put( key, orb.string_to_object( ref ));
742         }
743 
744         for( Enumeration e = names.keys(); e.hasMoreElements();)
745         {
746             Name key = (Name)e.nextElement();
747             String   ref = (String  )names.remove(key);
748             names.put( key, orb.string_to_object( ref ));
749         }
750 
751     }
752 
753     /* NamingContextExt */
754 
755     /**
756      * convert a name into its string representation
757      */
758 
759     public String   to_string(NameComponent[] n)
760         throws InvalidName
761     {
762         return Name.toString(n);
763     }
764 
765     /**
766      * convert a string into name
767      * @throws InvalidName
768      */
769 
770     public NameComponent[] to_name( String   sn )
771         throws InvalidName
772     {
773         return Name.toName( sn );
774     }
775 
776 
777     /**
778      *
779      */
780 
781     public String   to_url(String   addr, String   sn)
782         throws InvalidAddress, InvalidName
783     {
784         org.jacorb.orb.util.CorbaLoc corbaLoc;
785         try
786         {
787             corbaLoc =
788                 new org.jacorb.orb.util.CorbaLoc((org.jacorb.orb.ORB)orb, addr);
789             return corbaLoc.toCorbaName(sn);
790         }
791         catch (IllegalArgumentException   ia)
792         {
793             throw new InvalidAddress();
794         }
795     }
796 
797     /**
798      *
799      */
800 
801     public org.omg.CORBA.Object   resolve_str(String   n)
802         throws NotFound, CannotProceed, InvalidName
803     {
804         return resolve( to_name(n));
805     }
806 
807 
808     /**
809      * determine if non_existent
810      */
811 
812     private boolean isDead(org.omg.CORBA.Object   o)
813     {
814         boolean non_exist = true;
815         try
816         {
817             non_exist = o._non_existent();
818         } catch (org.omg.CORBA.SystemException   e)
819         {
820             non_exist = true;
821         }
822         return non_exist;
823     }
824 }
825
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