1 /*
   2  * Copyright (c) 1998, 2002, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 /*
  26  * Licensed Materials - Property of IBM
  27  * RMI-IIOP v1.0
  28  * Copyright IBM Corp. 1998 1999  All Rights Reserved
  29  *
  30  */
  31 
  32 package com.sun.corba.se.impl.util;
  33 
  34 import java.util.Stack;
  35 import java.util.Hashtable;
  36 import java.util.EmptyStackException;
  37 import java.util.Enumeration;
  38 
  39 // Really limited pool - in this case just creating several at a time...
  40 class RepositoryIdPool extends Stack {
  41 
  42     private static int MAX_CACHE_SIZE = 4;
  43     private RepositoryIdCache cache;
  44 
  45     public final synchronized RepositoryId popId() {
  46 
  47         try {
  48             return (RepositoryId)super.pop();
  49         }
  50         catch(EmptyStackException e) {
  51             increasePool(5);
  52             return (RepositoryId)super.pop();
  53         }
  54 
  55     }
  56 
  57     // Pool management
  58     final void increasePool(int size) {
  59         //if (cache.size() <= MAX_CACHE_SIZE)
  60         for (int i = size; i > 0; i--)
  61             push(new RepositoryId());
  62         /*
  63           // _REVISIT_ This will not work w/out either thread tracing or weak references.  I am
  64           // betting that thread tracing almost completely negates benefit of reuse.  Until either
  65           // 1.2 only inclusion or proof to the contrary, I'll leave it this way...
  66           else {
  67           int numToReclaim = cache.size() / 2;
  68           Enumeration keys = cache.keys();
  69           Enumeration elements = cache.elements();
  70           for (int i = numToReclaim; i > 0; i--) {
  71           Object key = keys.nextElement();
  72           Object element = elements.nextElement();
  73 
  74           push(element);
  75           cache.remove(key);
  76           }
  77           }
  78         */
  79     }
  80 
  81     final void setCaches(RepositoryIdCache cache) {
  82         this.cache = cache;
  83     }
  84 
  85 }
  86 
  87 public class RepositoryIdCache extends Hashtable {
  88 
  89     private RepositoryIdPool pool = new RepositoryIdPool();
  90 
  91     public RepositoryIdCache() {
  92         pool.setCaches(this);
  93     }
  94 
  95     public final synchronized RepositoryId getId(String key) {
  96         RepositoryId repId = (RepositoryId)super.get(key);
  97 
  98         if (repId != null)
  99             return repId;
 100         else {
 101             //repId = pool.popId().init(key);
 102             repId = new RepositoryId(key);
 103             put(key, repId);
 104             return repId;
 105         }
 106 
 107     }
 108 }