1 | /* |
2 | * @(#) $Id: IdentityHashSet.java 357871 2005-12-20 01:56:40Z trustin $ |
3 | * |
4 | * Copyright 2004 The Apache Software Foundation |
5 | * |
6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
7 | * you may not use this file except in compliance with the License. |
8 | * You may obtain a copy of the License at |
9 | * |
10 | * http://www.apache.org/licenses/LICENSE-2.0 |
11 | * |
12 | * Unless required by applicable law or agreed to in writing, software |
13 | * distributed under the License is distributed on an "AS IS" BASIS, |
14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
15 | * See the License for the specific language governing permissions and |
16 | * limitations under the License. |
17 | * |
18 | */ |
19 | package org.apache.mina.util; |
20 | |
21 | import java.util.AbstractSet; |
22 | import java.util.IdentityHashMap; |
23 | import java.util.Iterator; |
24 | import java.util.Map; |
25 | import java.util.Set; |
26 | |
27 | /** |
28 | * An {@link IdentityHashMap}-backed {@link Set}. |
29 | * |
30 | * @author The Apache Directory Project (dev@directory.apache.org) |
31 | * @version $Rev: 357871 $, $Date: 2005-12-20 10:56:40 +0900 (Tue, 20 Dec 2005) $ |
32 | */ |
33 | public class IdentityHashSet extends AbstractSet |
34 | { |
35 | private final Map delegate = new IdentityHashMap(); |
36 | |
37 | public IdentityHashSet() |
38 | { |
39 | } |
40 | |
41 | public int size() |
42 | { |
43 | return delegate.size(); |
44 | } |
45 | |
46 | public boolean contains( Object o ) |
47 | { |
48 | return delegate.containsKey( o ); |
49 | } |
50 | |
51 | public Iterator iterator() |
52 | { |
53 | return delegate.keySet().iterator(); |
54 | } |
55 | |
56 | public boolean add( Object arg0 ) |
57 | { |
58 | return delegate.put( arg0, Boolean.TRUE ) == null; |
59 | } |
60 | |
61 | public boolean remove( Object o ) |
62 | { |
63 | return delegate.remove( o ) != null; |
64 | } |
65 | |
66 | public void clear() |
67 | { |
68 | delegate.clear(); |
69 | } |
70 | } |