1 /*
2 * Copyright (c) 2013, 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 package sun.util.resources;
27
28 import java.util.AbstractSet;
29 import java.util.Collections;
30 import java.util.Enumeration;
31 import java.util.HashSet;
32 import java.util.Iterator;
33 import java.util.NoSuchElementException;
34 import java.util.ResourceBundle;
35 import java.util.Set;
36 import java.util.concurrent.ConcurrentHashMap;
37 import java.util.concurrent.ConcurrentMap;
38 import java.util.concurrent.atomic.AtomicMarkableReference;
39
40 /**
41 * ParallelListResourceBundle is another variant of ListResourceBundle
42 * supporting "parallel" contents provided by another resource bundle
43 * (OpenListResourceBundle). Parallel contents, if any, are added into this
44 * bundle on demand.
45 *
46 * @author Masayoshi Okutsu
47 */
48 public abstract class ParallelListResourceBundle extends ResourceBundle {
49 private volatile ConcurrentMap<String, Object> lookup;
50 private volatile Set<String> keyset;
51 private final AtomicMarkableReference<Object[][]> parallelContents
52 = new AtomicMarkableReference<>(null, false);
53
54 /**
55 * Sole constructor. (For invocation by subclass constructors, typically
56 * implicit.)
57 */
58 protected ParallelListResourceBundle() {
59 }
60
61 /**
62 * Returns an array in which each item is a pair of objects in an
63 * Object array. The first element of each pair is the key, which
64 * must be a String, and the second element is the value
65 * associated with that key. See the class description for
66 * details.
67 *
68 * @return an array of an Object array representing a key-value pair.
69 */
70 protected abstract Object[][] getContents();
71
72 /**
73 * Returns the parent of this resource bundle or null if there's no parent.
74 *
75 * @return the parent or null if no parent
76 */
77 ResourceBundle getParent() {
78 return parent;
79 }
80
81 /**
82 * Sets the parallel contents to the data given by rb. If rb is null, this
83 * bundle will be marked as `complete'.
84 *
85 * @param rb an OpenResourceBundle for parallel contents, or null indicating
86 * there are no parallel contents for this bundle
87 */
88 public void setParallelContents(OpenListResourceBundle rb) {
89 if (rb == null) {
90 parallelContents.compareAndSet(null, null, false, true);
91 } else {
92 parallelContents.compareAndSet(null, rb.getContents(), false, false);
93 }
94 }
95
96 /**
97 * Returns true if any parallel contents have been set or if this bundle is
98 * marked as complete.
99 *
100 * @return true if any parallel contents have been processed
101 */
102 boolean areParallelContentsComplete() {
103 // Quick check for `complete'
104 if (parallelContents.isMarked()) {
105 return true;
106 }
107 boolean[] done = new boolean[1];
108 Object[][] data = parallelContents.get(done);
109 return data != null || done[0];
110 }
111
112 @Override
113 protected Object handleGetObject(String key) {
114 if (key == null) {
115 throw new NullPointerException();
116 }
117
118 loadLookupTablesIfNecessary();
119 return lookup.get(key);
120 }
121
122 @Override
123 public Enumeration<String> getKeys() {
124 return Collections.enumeration(keySet());
125 }
126
127 @Override
128 public boolean containsKey(String key) {
129 return keySet().contains(key);
130 }
131
132 @Override
133 protected Set<String> handleKeySet() {
134 loadLookupTablesIfNecessary();
135 return lookup.keySet();
136 }
137
138 @Override
139 @SuppressWarnings("UnusedAssignment")
140 public Set<String> keySet() {
141 Set<String> ks;
142 while ((ks = keyset) == null) {
143 ks = new KeySet(handleKeySet(), parent);
144 synchronized (this) {
145 if (keyset == null) {
146 keyset = ks;
147 }
148 }
149 }
150 return ks;
151 }
152
153 /**
154 * Discards any cached keyset value. This method is called from
155 * LocaleData for re-creating a KeySet.
156 */
157 synchronized void resetKeySet() {
158 keyset = null;
159 }
160
161 /**
162 * Loads the lookup table if they haven't been loaded already.
163 */
164 void loadLookupTablesIfNecessary() {
165 ConcurrentMap<String, Object> map = lookup;
166 if (map == null) {
167 map = new ConcurrentHashMap<>();
168 for (Object[] item : getContents()) {
169 map.put((String) item[0], item[1]);
170 }
171 }
172
173 // If there's any parallel contents data, merge the data into map.
174 Object[][] data = parallelContents.getReference();
175 if (data != null) {
176 for (Object[] item : data) {
177 map.putIfAbsent((String) item[0], item[1]);
178 }
179 parallelContents.set(null, true);
180 }
181 if (lookup == null) {
182 synchronized (this) {
183 if (lookup == null) {
184 lookup = map;
185 }
186 }
187 }
188 }
189
190 /**
191 * This class implements the Set interface for
192 * ParallelListResourceBundle methods.
193 */
194 private static class KeySet extends AbstractSet<String> {
195 private final Set<String> set;
196 private final ResourceBundle parent;
197
198 private KeySet(Set<String> set, ResourceBundle parent) {
199 this.set = set;
200 this.parent = parent;
201 }
202
203 @Override
204 public boolean contains(Object o) {
205 if (set.contains(o)) {
206 return true;
207 }
208 return (parent != null) ? parent.containsKey((String) o) : false;
209 }
210
211 @Override
212 public Iterator<String> iterator() {
213 if (parent == null) {
214 return set.iterator();
215 }
216 return new Iterator<>() {
217 private Iterator<String> itr = set.iterator();
218 private boolean usingParent;
219
220 @Override
221 public boolean hasNext() {
222 if (itr.hasNext()) {
223 return true;
224 }
225 if (!usingParent) {
226 Set<String> nextset = new HashSet<>(parent.keySet());
227 nextset.removeAll(set);
228 itr = nextset.iterator();
229 usingParent = true;
230 }
231 return itr.hasNext();
232 }
233
234 @Override
235 public String next() {
236 if (hasNext()) {
237 return itr.next();
238 }
239 throw new NoSuchElementException();
240 }
241
242 @Override
243 public void remove() {
244 throw new UnsupportedOperationException();
245 }
246 };
247 }
248
249 @Override
250 public int size() {
251 if (parent == null) {
252 return set.size();
253 }
254 Set<String> allset = new HashSet<>(set);
255 allset.addAll(parent.keySet());
256 return allset.size();
257 }
258 }
259 }