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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/*
* 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 static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.Maps;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import javax.annotation.Nullable;
/**
* Utility {@link CacheLoader} implementations intended for use in testing.
*
* @author mike nonemacher
*/
@GwtCompatible(emulated = true)
class TestingCacheLoaders {
/**
* Returns a {@link CacheLoader} that implements a naive {@link CacheLoader#loadAll}, delegating
* {@link CacheLoader#load} calls to {@code loader}.
*/
static <K, V> CacheLoader<K, V> bulkLoader(final CacheLoader<K, V> loader) {
checkNotNull(loader);
return new CacheLoader<K, V>() {
@Override
public V load(K key) throws Exception {
return loader.load(key);
}
@Override
public Map<K, V> loadAll(Iterable<? extends K> keys) throws Exception {
Map<K, V> result = Maps.newHashMap(); // allow nulls
for (K key : keys) {
result.put(key, load(key));
}
return result;
}
};
}
/**
* Returns a {@link CacheLoader} that returns the given {@code constant} for every request.
*/
static <K, V> ConstantLoader<K, V> constantLoader(@Nullable V constant) {
return new ConstantLoader<K, V>(constant);
}
/**
* Returns a {@link CacheLoader} that returns the given {@code constant} for every request.
*/
static IncrementingLoader incrementingLoader() {
return new IncrementingLoader();
}
/**
* Returns a {@link CacheLoader} that throws the given error for every request.
*/
static <K, V> CacheLoader<K, V> errorLoader(final Error e) {
checkNotNull(e);
return new CacheLoader<K, V>() {
@Override
public V load(K key) {
throw e;
}
};
}
/**
* Returns a {@link CacheLoader} that throws the given exception for every request.
*/
static <K, V> CacheLoader<K, V> exceptionLoader(final Exception e) {
checkNotNull(e);
return new CacheLoader<K, V>() {
@Override
public V load(K key) throws Exception {
throw e;
}
};
}
/**
* Returns a {@link CacheLoader} that returns the key for every request.
*/
static <T> IdentityLoader<T> identityLoader() {
return new IdentityLoader<T>();
}
/**
* Returns a {@code new Object()} for every request, and increments a counter for every request.
* The count is accessible via {@link #getCount}.
*/
static class CountingLoader extends CacheLoader<Object, Object> {
private final AtomicInteger count = new AtomicInteger();
@Override
public Object load(Object from) {
count.incrementAndGet();
return new Object();
}
public int getCount() {
return count.get();
}
}
static final class ConstantLoader<K, V> extends CacheLoader<K, V> {
private final V constant;
ConstantLoader(V constant) {
this.constant = constant;
}
@Override
public V load(K key) {
return constant;
}
}
/**
* Returns a {@code new Object()} for every request, and increments a counter for every request.
* An {@code Integer} loader that returns the key for {@code load} requests, and increments the
* old value on {@code reload} requests. The load counts are accessible via {@link #getLoadCount}
* and {@link #getReloadCount}.
*/
static class IncrementingLoader extends CacheLoader<Integer, Integer> {
private final AtomicInteger countLoad = new AtomicInteger();
private final AtomicInteger countReload = new AtomicInteger();
@Override
public Integer load(Integer key) {
countLoad.incrementAndGet();
return key;
}
@GwtIncompatible("reload")
@Override
public ListenableFuture<Integer> reload(Integer key, Integer oldValue) {
countReload.incrementAndGet();
return Futures.immediateFuture(oldValue + 1);
}
public int getLoadCount() {
return countLoad.get();
}
public int getReloadCount() {
return countReload.get();
}
}
static final class IdentityLoader<T> extends CacheLoader<T, T> {
@Override
public T load(T key) {
return key;
}
}
}
|
