1 /***
2 * Copyright 2003-2010 Terracotta, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package net.sf.ehcache.hibernate.strategy;
17
18 import net.sf.ehcache.hibernate.regions.EhcacheEntityRegion;
19
20 import org.hibernate.cache.CacheException;
21 import org.hibernate.cache.EntityRegion;
22 import org.hibernate.cache.access.EntityRegionAccessStrategy;
23 import org.hibernate.cache.access.SoftLock;
24 import org.hibernate.cfg.Settings;
25
26 /***
27 * Ehcache specific read-only entity region access strategy
28 *
29 * @author Chris Dennis
30 */
31 public class ReadOnlyEhcacheEntityRegionAccessStrategy extends AbstractEhcacheAccessStrategy<EhcacheEntityRegion>
32 implements EntityRegionAccessStrategy {
33
34 /***
35 * Create a read-only access strategy accessing the given entity region.
36 */
37 public ReadOnlyEhcacheEntityRegionAccessStrategy(EhcacheEntityRegion region, Settings settings) {
38 super(region, settings);
39 }
40
41 /***
42 * {@inheritDoc}
43 */
44 public EntityRegion getRegion() {
45 return region;
46 }
47
48 /***
49 * {@inheritDoc}
50 */
51 public Object get(Object key, long txTimestamp) throws CacheException {
52 return region.get(key);
53 }
54
55 /***
56 * {@inheritDoc}
57 */
58 public boolean putFromLoad(Object key, Object value, long txTimestamp, Object version, boolean minimalPutOverride)
59 throws CacheException {
60 if (minimalPutOverride && region.contains(key)) {
61 return false;
62 } else {
63 region.put(key, value);
64 return true;
65 }
66 }
67
68 /***
69 * Throws UnsupportedOperationException since this cache is read-only
70 *
71 * @throws UnsupportedOperationException always
72 */
73 public SoftLock lockItem(Object key, Object version) throws UnsupportedOperationException {
74 throw new UnsupportedOperationException("Can't write to a readonly object");
75 }
76
77 /***
78 * A no-op since this cache is read-only
79 */
80 public void unlockItem(Object key, SoftLock lock) throws CacheException {
81
82 }
83
84 /***
85 * This cache is asynchronous hence a no-op
86 */
87 public boolean insert(Object key, Object value, Object version) throws CacheException {
88 return false;
89 }
90
91 /***
92 * {@inheritDoc}
93 */
94 public boolean afterInsert(Object key, Object value, Object version) throws CacheException {
95 region.put(key, value);
96 return true;
97 }
98
99 /***
100 * Throws UnsupportedOperationException since this cache is read-only
101 *
102 * @throws UnsupportedOperationException always
103 */
104 public boolean update(Object key, Object value, Object currentVersion, Object previousVersion) throws UnsupportedOperationException {
105 throw new UnsupportedOperationException("Can't write to a readonly object");
106 }
107
108 /***
109 * Throws UnsupportedOperationException since this cache is read-only
110 *
111 * @throws UnsupportedOperationException always
112 */
113 public boolean afterUpdate(Object key, Object value, Object currentVersion, Object previousVersion, SoftLock lock)
114 throws UnsupportedOperationException {
115 throw new UnsupportedOperationException("Can't write to a readonly object");
116 }
117 }