001    /**
002     * Copyright (c) 2000-2013 Liferay, Inc. All rights reserved.
003     *
004     * This library is free software; you can redistribute it and/or modify it under
005     * the terms of the GNU Lesser General Public License as published by the Free
006     * Software Foundation; either version 2.1 of the License, or (at your option)
007     * any later version.
008     *
009     * This library is distributed in the hope that it will be useful, but WITHOUT
010     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
011     * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
012     * details.
013     */
014    
015    package com.liferay.portal.kernel.cache;
016    
017    import com.liferay.portal.kernel.concurrent.CompeteLatch;
018    
019    import java.io.Serializable;
020    
021    import java.util.Collection;
022    import java.util.concurrent.ConcurrentHashMap;
023    import java.util.concurrent.ConcurrentMap;
024    
025    /**
026     * @author Shuyang Zhou
027     */
028    public class BlockingPortalCache implements PortalCache {
029    
030            public BlockingPortalCache(PortalCache portalCache) {
031                    _portalCache = portalCache;
032            }
033    
034            @Override
035            public void destroy() {
036            }
037    
038            @Override
039            public Collection<Object> get(Collection<Serializable> keys) {
040                    return _portalCache.get(keys);
041            }
042    
043            @Override
044            public Object get(Serializable key) {
045                    Object value = _portalCache.get(key);
046    
047                    if (value != null) {
048                            return value;
049                    }
050    
051                    CompeteLatch lastCompeteLatch = _competeLatch.get();
052    
053                    if (lastCompeteLatch != null) {
054                            lastCompeteLatch.done();
055    
056                            _competeLatch.set(null);
057                    }
058    
059                    CompeteLatch currentCompeteLatch = _competeLatchMap.get(key);
060    
061                    if (currentCompeteLatch == null) {
062                            CompeteLatch newCompeteLatch = new CompeteLatch();
063    
064                            currentCompeteLatch = _competeLatchMap.putIfAbsent(
065                                    key, newCompeteLatch);
066    
067                            if (currentCompeteLatch == null) {
068                                    currentCompeteLatch = newCompeteLatch;
069                            }
070                    }
071    
072                    _competeLatch.set(currentCompeteLatch);
073    
074                    if (!currentCompeteLatch.compete()) {
075                            try {
076                                    currentCompeteLatch.await();
077                            }
078                            catch (InterruptedException ie) {
079                            }
080    
081                            _competeLatch.set(null);
082    
083                            value = _portalCache.get(key);
084                    }
085    
086                    return value;
087            }
088    
089            @Override
090            public String getName() {
091                    return _portalCache.getName();
092            }
093    
094            @Override
095            public void put(Serializable key, Object value) {
096                    if (key == null) {
097                            throw new IllegalArgumentException("Key is null");
098                    }
099    
100                    if (value == null) {
101                            throw new IllegalArgumentException("Value is null");
102                    }
103    
104                    _portalCache.put(key, value);
105    
106                    CompeteLatch competeLatch = _competeLatch.get();
107    
108                    if (competeLatch != null) {
109                            competeLatch.done();
110    
111                            _competeLatch.set(null);
112                    }
113    
114                    _competeLatchMap.remove(key);
115            }
116    
117            @Override
118            public void put(Serializable key, Object value, int timeToLive) {
119                    if (key == null) {
120                            throw new IllegalArgumentException("Key is null");
121                    }
122    
123                    if (value == null) {
124                            throw new IllegalArgumentException("Value is null");
125                    }
126    
127                    _portalCache.put(key, value, timeToLive);
128    
129                    CompeteLatch competeLatch = _competeLatch.get();
130    
131                    if (competeLatch != null) {
132                            competeLatch.done();
133    
134                            _competeLatch.set(null);
135                    }
136    
137                    _competeLatchMap.remove(key);
138            }
139    
140            @Override
141            public void put(Serializable key, Serializable value) {
142                    if (key == null) {
143                            throw new IllegalArgumentException("Key is null");
144                    }
145    
146                    if (value == null) {
147                            throw new IllegalArgumentException("Value is null");
148                    }
149    
150                    _portalCache.put(key, value);
151    
152                    CompeteLatch competeLatch = _competeLatch.get();
153    
154                    if (competeLatch != null) {
155                            competeLatch.done();
156    
157                            _competeLatch.set(null);
158                    }
159    
160                    _competeLatchMap.remove(key);
161            }
162    
163            @Override
164            public void put(Serializable key, Serializable value, int timeToLive) {
165                    if (key == null) {
166                            throw new IllegalArgumentException("Key is null");
167                    }
168    
169                    if (value == null) {
170                            throw new IllegalArgumentException("Value is null");
171                    }
172    
173                    _portalCache.put(key, value, timeToLive);
174    
175                    CompeteLatch competeLatch = _competeLatch.get();
176    
177                    if (competeLatch != null) {
178                            competeLatch.done();
179    
180                            _competeLatch.set(null);
181                    }
182    
183                    _competeLatchMap.remove(key);
184            }
185    
186            @Override
187            public void registerCacheListener(CacheListener cacheListener) {
188                    _portalCache.registerCacheListener(cacheListener);
189            }
190    
191            @Override
192            public void registerCacheListener(
193                    CacheListener cacheListener, CacheListenerScope cacheListenerScope) {
194    
195                    _portalCache.registerCacheListener(cacheListener, cacheListenerScope);
196            }
197    
198            @Override
199            public void remove(Serializable key) {
200                    _portalCache.remove(key);
201    
202                    CompeteLatch competeLatch = _competeLatchMap.remove(key);
203    
204                    if (competeLatch != null) {
205                            competeLatch.done();
206                    }
207            }
208    
209            @Override
210            public void removeAll() {
211                    _portalCache.removeAll();
212                    _competeLatchMap.clear();
213            }
214    
215            @Override
216            public void unregisterCacheListener(CacheListener cacheListener) {
217                    _portalCache.unregisterCacheListener(cacheListener);
218            }
219    
220            @Override
221            public void unregisterCacheListeners() {
222                    _portalCache.unregisterCacheListeners();
223            }
224    
225            private static ThreadLocal<CompeteLatch> _competeLatch =
226                    new ThreadLocal<CompeteLatch>();
227    
228            private final ConcurrentMap<Serializable, CompeteLatch> _competeLatchMap =
229                    new ConcurrentHashMap<Serializable, CompeteLatch>();
230            private final PortalCache _portalCache;
231    
232    }