001 /*
002 GRANITE DATA SERVICES
003 Copyright (C) 2012 GRANITE DATA SERVICES S.A.S.
004
005 This file is part of Granite Data Services.
006
007 Granite Data Services is free software; you can redistribute it and/or modify
008 it under the terms of the GNU Library General Public License as published by
009 the Free Software Foundation; either version 2 of the License, or (at your
010 option) any later version.
011
012 Granite Data Services is distributed in the hope that it will be useful, but
013 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015 for more details.
016
017 You should have received a copy of the GNU Library General Public License
018 along with this library; if not, see <http://www.gnu.org/licenses/>.
019 */
020
021 package org.granite.client.tide.data.impl;
022
023 import java.util.ArrayList;
024 import java.util.List;
025 import java.util.WeakHashMap;
026
027 import org.granite.client.tide.data.Identifiable;
028
029 /**
030 * Implementation of HashSet that holds weak references to UID entities
031 *
032 * @author William DRAI
033 */
034 public class UIDWeakSet {
035
036 private WeakHashMap<Object, Object>[] table;
037
038
039 public UIDWeakSet() {
040 this(64);
041 }
042
043 @SuppressWarnings("unchecked")
044 public UIDWeakSet(int capacity) {
045 table = new WeakHashMap[capacity];
046 }
047
048 public void clear() {
049 for (int i = 0; i < table.length; i++)
050 table[i] = null;
051 }
052
053 public Identifiable put(Identifiable uidObject) {
054 int h = hash(uidObject.getClass().getName() + ":" + uidObject.getUid());
055
056 WeakHashMap<Object, Object> dic = table[h];
057 if (dic == null) {
058 dic = new WeakHashMap<Object, Object>();
059 table[h] = dic;
060 }
061
062 Identifiable old = null;
063 for (Object o : dic.keySet()) {
064 if (o == uidObject)
065 return (Identifiable)o;
066
067 if (((Identifiable)o).getUid() == uidObject.getUid() && o.getClass().getName().equals(uidObject.getClass().getName())) {
068 old = (Identifiable)o;
069 dic.remove(o);
070 break;
071 }
072 }
073
074 dic.put(uidObject, null);
075
076 return old;
077 }
078
079 public Identifiable get(String uid) {
080 int h = hash(uid);
081
082 Identifiable uidObject = null;
083
084 WeakHashMap<Object, Object> dic = table[h];
085 if (dic != null) {
086 for (Object o : dic.keySet()) {
087 if ((o.getClass().getName() + ":" + ((Identifiable)o).getUid()).equals(uid)) {
088 uidObject = (Identifiable)o;
089 break;
090 }
091 }
092 }
093
094 return uidObject;
095 }
096
097 public static interface Matcher {
098
099 public boolean match(Object o);
100 }
101
102 public Object find(Matcher matcher) {
103 for (int i = 0; i < table.length; i++) {
104 WeakHashMap<Object, Object> dic = table[i];
105 if (dic != null) {
106 for (Object o : dic.keySet()) {
107 if (matcher.match(o))
108 return o;
109 }
110 }
111 }
112 return null;
113 }
114
115 public static interface Operation {
116
117 public void apply(Object o);
118 }
119
120 public void apply(Operation operation) {
121 for (int i = 0; i < table.length; i++) {
122 WeakHashMap<Object, Object> dic = table[i];
123 if (dic != null) {
124 for (Object o : dic.keySet())
125 operation.apply(o);
126 }
127 }
128 }
129
130 public Identifiable remove(String uid) {
131 int h = hash(uid);
132
133 Identifiable uidObject = null;
134
135 WeakHashMap<Object, Object> dic = table[h];
136 if (dic != null) {
137 for (Object o : dic.keySet()) {
138 if ((o.getClass().getName() + ":" + ((Identifiable)o).getUid()).equals(uid)) {
139 uidObject = (Identifiable)o;
140 dic.remove(o);
141 break;
142 }
143 }
144 }
145
146 return uidObject;
147 }
148
149 public int size() {
150 int size = 0;
151
152 for (int i = 0; i < table.length; i++) {
153 WeakHashMap<Object, Object> dic = table[i];
154 if (dic != null)
155 size += dic.size();
156 }
157
158 return size;
159 }
160
161 public List<Object> data() {
162 List<Object> d = new ArrayList<Object>();
163
164 for (int i = 0; i < table.length; i++) {
165 WeakHashMap<Object, Object> dic = table[i];
166 if (dic != null)
167 d.addAll(dic.keySet());
168 }
169 return d;
170 }
171
172 private int hash(String uid) {
173 int h = 0;
174 int max = uid.length();
175 for (int i = 0; i < max; i++)
176 h = (31 * h) + uid.charAt(i);
177 return (Math.abs(h) % table.length);
178 }
179 }