AssociationMap.java revision 524:dcaa586ab756 
1/*
2 * Copyright (c) 1997, 2012, 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
26package com.sun.xml.internal.bind.v2.runtime;
27
28import java.util.HashSet;
29import java.util.IdentityHashMap;
30import java.util.Map;
31import java.util.Set;
32
33/**
34 * Bi-directional map between elements, inner peers,
35 * and outer peers.
36 *
37 * <p>
38 * TODO: this should be rewritten for efficiency.
39 *
40 * @since 2.0
41 *
42 * @author
43 *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
44 */
45public final class AssociationMap<XmlNode> {
46    final static class Entry<XmlNode> {
47        /** XML element. */
48        private XmlNode element;
49        /** inner peer, or null. */
50        private Object inner;
51        /** outer peer, or null. */
52        private Object outer;
53
54        public XmlNode element() {
55                return element;
56        }
57        public Object inner() {
58                return inner;
59        }
60        public Object outer() {
61                return outer;
62        }
63    }
64
65    private final Map<XmlNode,Entry<XmlNode>> byElement = new IdentityHashMap<XmlNode,Entry<XmlNode>>();
66    private final Map<Object,Entry<XmlNode>> byPeer = new IdentityHashMap<Object,Entry<XmlNode>>();
67    private final Set<XmlNode> usedNodes = new HashSet<XmlNode>();
68
69    /** Records the new element&lt;->inner peer association. */
70    public void addInner( XmlNode element, Object inner ) {
71        Entry<XmlNode> e = byElement.get(element);
72        if(e!=null) {
73                if(e.inner!=null)
74                byPeer.remove(e.inner);
75            e.inner = inner;
76        } else {
77                e = new Entry<XmlNode>();
78            e.element = element;
79            e.inner = inner;
80        }
81
82        byElement.put(element,e);
83
84        Entry<XmlNode> old = byPeer.put(inner,e);
85        if(old!=null) {
86            if(old.outer!=null)
87                byPeer.remove(old.outer);
88            if(old.element!=null)
89                byElement.remove(old.element);
90        }
91    }
92
93    /** Records the new element&lt;->outer peer association. */
94    public void addOuter( XmlNode element, Object outer ) {
95        Entry<XmlNode> e = byElement.get(element);
96        if(e!=null) {
97            if(e.outer!=null)
98                byPeer.remove(e.outer);
99            e.outer = outer;
100        } else {
101            e = new Entry<XmlNode>();
102            e.element = element;
103            e.outer = outer;
104        }
105
106        byElement.put(element,e);
107
108        Entry<XmlNode> old = byPeer.put(outer,e);
109        if(old!=null) {
110            old.outer=null;
111
112            if(old.inner==null)
113                // remove this entry
114                byElement.remove(old.element);
115        }
116    }
117
118    public void addUsed( XmlNode n ) {
119        usedNodes.add(n);
120    }
121
122    public Entry<XmlNode> byElement( Object e ) {
123        return byElement.get(e);
124    }
125
126    public Entry<XmlNode> byPeer( Object o ) {
127        return byPeer.get(o);
128    }
129
130    public Object getInnerPeer( XmlNode element ) {
131        Entry e = byElement(element);
132        if(e==null)     return null;
133        else            return e.inner;
134    }
135
136    public Object getOuterPeer( XmlNode element ) {
137        Entry e = byElement(element);
138        if(e==null)     return null;
139        else            return e.outer;
140    }
141}
142