libjava/classpath/gnu/CORBA/Poa/AOM.java

   1 /* AOM.java --
   2    Copyright (C) 2005 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package gnu.CORBA.Poa;
  40
  41 import gnu.CORBA.ByteArrayComparator;
  42
  43 import org.omg.CORBA.portable.Delegate;
  44 import org.omg.CORBA.portable.ObjectImpl;
  45 import org.omg.PortableServer.Servant;
  46
  47 import java.util.Iterator;
  48 import java.util.Map;
  49 import java.util.Set;
  50 import java.util.TreeMap;
  51
  52 /**
  53  * Implements the conception of the Active Object Map.
  54  * If the POA supports the RETAIN policy, it maintains an Active
  55  * Object Map, that associates Object Ids with active servants.
  56  * Each association constitutes an active object. We use a single map
  57  * for all POAs on the given orb.
  58  *
  59  * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)
  60  */
  61 public class AOM
  62 {
  63   /**
  64    * The reference data about the object, placed on the AOM.
  65    */
  66   public class Obj
  67   {
  68     /**
  69      * Create an initialised instance.
  70      */
  71     Obj(gnuServantObject _object, byte[] _key, Servant _servant, gnuPOA _poa)
  72     {
  73       object = _object;
  74       key = _key;
  75       servant = _servant;
  76       poa = _poa;
  77     }
  78
  79     /**
  80      * The object.
  81      */
  82     public final gnuServantObject object;
  83
  84     /**
  85      * The servant, serving the given object.
  86      */
  87     public Servant servant;
  88
  89     /**
  90      * The local servant that once served this object.
  91      * This field is used by {@link ForwardedServant} when it discovers that
  92      * the forwarding chaing returns back to the original location.
  93      * It should not be used anywhere else.
  94      */
  95     Servant primary_servant;
  96
  97     /**
  98      * The POA, where the object is connected.
  99      */
 100     public final gnuPOA poa;
 101
 102     /**
 103      * The object key.
 104      */
 105     public final byte[] key;
 106
 107     /**
 108      * If true, this entry is deactivated.
 109      */
 110     public boolean deactivated;
 111
 112     /**
 113      * Set the servant value, preserving any non null
 114      * value as the primary servant.
 115      */
 116     public void setServant(Servant s)
 117     {
 118       if (primary_servant == null)
 119         primary_servant = s;
 120       servant = s;
 121     }
 122
 123     /**
 124      * Get the servant.
 125      */
 126     public Servant getServant()
 127     {
 128       return servant;
 129     }
 130
 131     /**
 132      * Get the deactivation state.
 133      */
 134     public boolean isDeactiveted()
 135     {
 136       return deactivated;
 137     }
 138
 139     /**
 140      * Set the deactivation state.
 141      */
 142     public void setDeactivated(boolean state)
 143     {
 144       deactivated = state;
 145     }
 146   }
 147
 148   /**
 149    * The free number to give for the next instance.
 150    * This field is incremented each time the
 151    * new collection of the connected objects is created.
 152    * Each collection has its own unique instance number.
 153    */
 154   private static long free_id;
 155
 156   /**
 157    * The map of the all connected objects, maps the object key to the
 158    * object.
 159    */
 160   Map objects = new TreeMap(new ByteArrayComparator());
 161
 162   /**
 163    * Get the record of the stored object. If the object is mapped several times
 164    * under the different keys, one of the mappings is used.
 165    *
 166    * @param object the stored object
 167    *
 168    * @return the record about the stored object, null if this object is not
 169    * stored here.
 170    */
 171   public Obj findObject(org.omg.CORBA.Object stored_object)
 172   {
 173     if (stored_object == null)
 174       return null;
 175
 176     Map.Entry item;
 177     Iterator iter;
 178     Obj ref;
 179
 180     if (stored_object instanceof ObjectImpl)
 181       {
 182         // If the delegate is available, search by delegate.
 183         Delegate d = ((ObjectImpl) stored_object)._get_delegate();
 184         Delegate d2;
 185
 186         if (d != null)
 187           {
 188             iter = objects.entrySet().iterator();
 189             while (iter.hasNext())
 190               {
 191                 item = (Map.Entry) iter.next();
 192                 ref = (Obj) item.getValue();
 193                 d2 = ref.object._get_delegate();
 194
 195                 if (d == d2 || (d2 != null && d2.equals(d)))
 196                   return ref;
 197               }
 198           }
 199       }
 200
 201     // For other objects (or if not possible to get the delegate),
 202     // search by .equals
 203     iter = objects.entrySet().iterator();
 204     while (iter.hasNext())
 205       {
 206         item = (Map.Entry) iter.next();
 207         ref = (Obj) item.getValue();
 208         if (stored_object.equals(ref.object))
 209           return ref;
 210       }
 211     return null;
 212   }
 213
 214   /**
 215    * Find the reference info for the given servant. If the servant is mapped to
 216    * several objects, this returns the first found occurence.
 217    *
 218    * @param servant a servant to find.
 219    *
 220    * @return the servant/object/POA binding or null if no such found.
 221    */
 222   public Obj findServant(Servant servant)
 223   {
 224     if (servant == null)
 225       return null;
 226
 227     Map.Entry item;
 228     Iterator iter = objects.entrySet().iterator();
 229     Obj ref;
 230
 231     while (iter.hasNext())
 232       {
 233         item = (Map.Entry) iter.next();
 234         ref = (Obj) item.getValue();
 235         if (servant.equals(ref.servant))
 236           return ref;
 237       }
 238     return null;
 239   }
 240
 241   /**
 242    * Find the reference info for the given servant.
 243    * If the servant is mapped to several objects, this
 244    * returns the first found occurence.
 245    *
 246    * @param servant a servant to find.
 247    * @param speficies if to search for the inactive (true) or active
 248    * (false) servant. A servant with unmatching activity is ignored
 249    * by this method.
 250    *
 251    * @return the servant/object/POA binding or null if no such found.
 252    */
 253   public Obj findServant(Servant servant, boolean inactive)
 254   {
 255     if (servant == null)
 256       return null;
 257
 258     Map.Entry item;
 259     Iterator iter = objects.entrySet().iterator();
 260     Obj ref;
 261
 262     while (iter.hasNext())
 263       {
 264         item = (Map.Entry) iter.next();
 265         ref = (Obj) item.getValue();
 266         if (ref.deactivated == inactive)
 267           if (ref.servant != null)
 268             if (servant.equals(ref.servant))
 269               return ref;
 270       }
 271     return null;
 272   }
 273
 274   /**
 275    * Add the new object to the repository. The object key is
 276    * generated automatically.
 277    *
 278    * @param object the object to add.
 279    * @param servant a servant, serving the given object.
 280    * @param poa the poa, where the object is connected.
 281    *
 282    * @return the newly created object record.
 283    */
 284   public Obj add(gnuServantObject object, Servant servant, gnuPOA poa)
 285   {
 286     return add(generateObjectKey(object), object, servant, poa);
 287   }
 288
 289   /**
 290    * Add the new object to the repository.
 291    *
 292    * @param key the object key.
 293    * @param object the object to add.
 294    * @param servant a servant, serving the given object.
 295    * @param poa the POA, where the object is connected.
 296    */
 297   public Obj add(byte[] key, gnuServantObject object, Servant servant,
 298                  gnuPOA poa
 299                 )
 300   {
 301     Obj rec = new Obj(object, key, servant, poa);
 302     objects.put(key, rec);
 303     return rec;
 304   }
 305
 306   /**
 307    * Add the new object to the repository.
 308    *
 309    * @param delegate the delegate, providing data about the servant, key, POA
 310    * and object.
 311    * @param port the port that this object would take.
 312    */
 313   public Obj add(ServantDelegateImpl delegate)
 314   {
 315     Obj rec =
 316       new Obj(delegate.object, delegate.servant_id, delegate.servant,
 317               delegate.poa
 318              );
 319     objects.put(delegate.servant_id, rec);
 320     return rec;
 321   }
 322
 323   /**
 324    * Put back the definition structure that has probably been removed earlier.
 325    */
 326   public void put(Obj obj)
 327   {
 328     objects.put(obj.key, obj);
 329   }
 330
 331   /**
 332    * Get the stored object.
 333    *
 334    * @param key the key (in the byte array form).
 335    *
 336    * @return the matching object, null if none is matching.
 337    */
 338   public Obj get(byte[] key)
 339   {
 340     return (Obj) objects.get(key);
 341   }
 342
 343   /**
 344    * Get the map key set.
 345    */
 346   public Set keySet()
 347   {
 348     return objects.keySet();
 349   }
 350
 351   /**
 352    * Remove the given object, indiciating it by the key.
 353    *
 354    * @param object the object to remove.
 355    */
 356   public void remove(byte[] key)
 357   {
 358     objects.remove(key);
 359   }
 360
 361   /**
 362    * Generate the object key, unique in the currently
 363    * running java virtual machine. The passed object
 364    * parameter is currently not in use.
 365    *
 366    * @return the generated key.
 367    */
 368   protected byte[] generateObjectKey(org.omg.CORBA.Object object)
 369   {
 370     byte[] key;
 371
 372     // The repetetive keys cannot be generated, but theoretically
 373     // the same keys can be passed when calling add(byte[]...).
 374     // Hence we check if the key is not already in the map and,
 375     // if it is, use the subsequent value.
 376     do
 377       {
 378         key = getFreeId();
 379       }
 380     while (objects.containsKey(key));
 381     return key;
 382   }
 383
 384   /**
 385    * Get the next free 8 byte id, surely unique between calls of this
 386    * method for the currently running virtual machine.
 387    */
 388   public static synchronized byte[] getFreeId()
 389   {
 390     byte[] r = new byte[ 8 ];
 391
 392     // Start from the faster-changing.
 393     r [ 0 ] = ((byte) (0xff & free_id));
 394     r [ 1 ] = ((byte) (0xff & (free_id >> 8)));
 395     r [ 2 ] = ((byte) (0xff & (free_id >> 16)));
 396     r [ 3 ] = ((byte) (0xff & (free_id >> 24)));
 397     r [ 4 ] = ((byte) (0xff & (free_id >> 32)));
 398     r [ 5 ] = ((byte) (0xff & (free_id >> 40)));
 399     r [ 6 ] = ((byte) (0xff & (free_id >> 48)));
 400     r [ 7 ] = ((byte) (0xff & (free_id >> 56)));
 401
 402     free_id++;
 403
 404     return r;
 405   }
 406 }