NoIdentityMap


1   /*
2    * The contents of this file are subject to the terms 
3    * of the Common Development and Distribution License 
4    * (the "License").  You may not use this file except 
5    * in compliance with the License.
6    * 
7    * You can obtain a copy of the license at 
8    * glassfish/bootstrap/legal/CDDLv1.0.txt or 
9    * https://glassfish.dev.java.net/public/CDDLv1.0.html. 
10   * See the License for the specific language governing 
11   * permissions and limitations under the License.
12   * 
13   * When distributing Covered Code, include this CDDL 
14   * HEADER in each file and include the License file at 
15   * glassfish/bootstrap/legal/CDDLv1.0.txt.  If applicable, 
16   * add the following below this CDDL HEADER, with the 
17   * fields enclosed by brackets "[]" replaced with your 
18   * own identifying information: Portions Copyright [yyyy] 
19   * [name of copyright owner]
20   */
21  // Copyright (c) 1998, 2005, Oracle. All rights reserved.  
22  package oracle.toplink.essentials.internal.identitymaps;
23  
24  import java.util.*;
25  
26  /**
27   * <p><b>Purpose</b>: Provide the capability to not cache objects at all.
28   * <p><b>Responsibilities</b>:<ul>
29   * <li> Do nothing when an object is cached
30   * </ul>
31   *    @since TOPLink/Java 1.0
32   */
33  public class NoIdentityMap extends IdentityMap {
34      public NoIdentityMap(int size) {
35          super(size);
36      }
37  
38      /**
39       *    locking for no identity.
40       */
41      public CacheKey acquire(Vector primaryKey) {
42          CacheKey cacheKey = new CacheKey(primaryKey);
43          cacheKey.acquire();
44          return cacheKey;
45      }
46  
47      /**
48       * INTERNAL:
49       * Used to print all the Locks in every identity map in this session.
50       * The output of this method will go to log passed in as a parameter.
51       */
52      public void collectLocks(HashMap threadList) {
53      }
54  
55      /**
56       * Allow for the cache to be iterated on.
57       */
58      public Enumeration elements() {
59          return new Vector(1).elements();
60      }
61  
62      /**
63       *    Return the object cached in the identity map
64       *  Return null as no object is cached in the no IM.
65       */
66      public Object   get(Vector primaryKey) {
67          return null;
68      }
69  
70      /**
71       *    Return null since no objects are actually cached.
72       */
73      protected CacheKey getCacheKey(CacheKey searchKey) {
74          return null;
75      }
76  
77      /**
78       *    @return 0 (zero)
79       */
80      public int getSize() {
81          return 0;
82      }
83  
84      /**
85       * Return the number of actual objects of type myClass in the IdentityMap.
86       * Recurse = true will include subclasses of myClass in the count.
87       */
88      public int getSize(Class   myClass, boolean recurse) {
89          return 0;
90      }
91  
92      /**
93       *    Get the write lock value from the cache key associated to the primarykey
94       */
95      public Object   getWriteLockValue(Vector primaryKey) {
96          return null;
97      }
98  
99      /**
100      * Allow for the cache keys to be iterated on.
101      */
102     public Enumeration keys() {
103         return new Vector(1).elements();
104     }
105 
106     /**
107      * DO NOTHING.
108      */
109     public CacheKey put(Vector aVector, Object   object, Object   writeLockValue, long readTime) {
110         return null;
111     }
112 
113     /**
114      * DO NOTHING
115      */
116     public void put(CacheKey key) {
117         return;
118     }
119 
120     /**
121      * Do Nothing.
122      * Return null, since no objects are cached.
123      */
124     public Object   remove(Vector primaryKey) {
125         return null;
126     }
127 
128     /**
129      * Do Nothing
130      * Return null, since no objects are cached.
131      */
132     public Object   remove(CacheKey searchKey) {
133         return null;
134     }
135 
136     public void setWriteLockValue(Vector primaryKey, Object   writeLockValue) {
137     }
138 }
139
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags