1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.common.cache;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Preconditions;
import com.google.common.collect.ForwardingObject;
import com.google.common.collect.ImmutableMap;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* A cache which forwards all its method calls to another cache. Subclasses should override one or
* more methods to modify the behavior of the backing cache as desired per the <a
* href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
*
* @author Charles Fry
* @since 10.0
*/
@GwtIncompatible
public abstract class ForwardingCache<K, V> extends ForwardingObject implements Cache<K, V> {
/** Constructor for use by subclasses. */
protected ForwardingCache() {}
@Override
protected abstract Cache<K, V> delegate();
/** @since 11.0 */
@Override
public @Nullable V getIfPresent(Object key) {
return delegate().getIfPresent(key);
}
/** @since 11.0 */
@Override
public V get(K key, Callable<? extends V> valueLoader) throws ExecutionException {
return delegate().get(key, valueLoader);
}
/** @since 11.0 */
@Override
public ImmutableMap<K, V> getAllPresent(Iterable<?> keys) {
return delegate().getAllPresent(keys);
}
/** @since 11.0 */
@Override
public void put(K key, V value) {
delegate().put(key, value);
}
/** @since 12.0 */
@Override
public void putAll(Map<? extends K, ? extends V> m) {
delegate().putAll(m);
}
@Override
public void invalidate(Object key) {
delegate().invalidate(key);
}
/** @since 11.0 */
@Override
public void invalidateAll(Iterable<?> keys) {
delegate().invalidateAll(keys);
}
@Override
public void invalidateAll() {
delegate().invalidateAll();
}
@Override
public long size() {
return delegate().size();
}
@Override
public CacheStats stats() {
return delegate().stats();
}
@Override
public ConcurrentMap<K, V> asMap() {
return delegate().asMap();
}
@Override
public void cleanUp() {
delegate().cleanUp();
}
/**
* A simplified version of {@link ForwardingCache} where subclasses can pass in an already
* constructed {@link Cache} as the delegate.
*
* @since 10.0
*/
public abstract static class SimpleForwardingCache<K, V> extends ForwardingCache<K, V> {
private final Cache<K, V> delegate;
protected SimpleForwardingCache(Cache<K, V> delegate) {
this.delegate = Preconditions.checkNotNull(delegate);
}
@Override
protected final Cache<K, V> delegate() {
return delegate;
}
}
}
|