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
|
/*
* Copyright 2023 Code Intelligence GmbH
*
* 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.code_intelligence.jazzer.mutation.support;
import static java.util.stream.Collectors.toSet;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.util.AbstractMap.SimpleEntry;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
/**
* An unoptimized version of a {@link java.util.WeakHashMap} with the semantics of a
* {@link java.util.IdentityHashMap}.
*
* <p>If this class ever becomes a bottleneck, e.g. because of the IdentityWeakReference
* allocations, it should be replaced by a copy of the * {@link java.util.WeakHashMap} code with all
* {@code equals} calls dropped and all {@code hashCode} * calls replaced with {@link
* System#identityHashCode}.
*/
public final class WeakIdentityHashMap<K, V> implements Map<K, V> {
private final HashMap<WeakReference<K>, V> map = new HashMap<>();
private final ReferenceQueue<K> weaklyReachables = new ReferenceQueue<>();
@Override
public int size() {
removeNewWeaklyReachables();
return map.size();
}
@Override
public boolean isEmpty() {
removeNewWeaklyReachables();
return map.isEmpty();
}
@Override
public boolean containsKey(Object key) {
removeNewWeaklyReachables();
return map.containsKey(new IdentityWeakReference<>(key));
}
@Override
public boolean containsValue(Object value) {
removeNewWeaklyReachables();
return map.containsValue(value);
}
@Override
public V get(Object key) {
removeNewWeaklyReachables();
return map.get(new IdentityWeakReference<>(key));
}
@Override
public V put(K key, V value) {
removeNewWeaklyReachables();
return map.put(new IdentityWeakReference<>(key, weaklyReachables), value);
}
@Override
public V remove(Object key) {
removeNewWeaklyReachables();
return map.remove(new IdentityWeakReference<>(key));
}
@Override
public void putAll(Map<? extends K, ? extends V> otherMap) {
removeNewWeaklyReachables();
for (Entry<? extends K, ? extends V> entry : otherMap.entrySet()) {
map.put(new IdentityWeakReference<>(entry.getKey(), weaklyReachables), entry.getValue());
}
}
@Override
public void clear() {
map.clear();
}
@Override
public Set<K> keySet() {
removeNewWeaklyReachables();
return map.keySet().stream().map(WeakReference::get).filter(Objects::nonNull).collect(toSet());
}
@Override
public Collection<V> values() {
removeNewWeaklyReachables();
return map.values();
}
@Override
public Set<Entry<K, V>> entrySet() {
removeNewWeaklyReachables();
return map.entrySet()
.stream()
.map(e -> new SimpleEntry<>(e.getKey().get(), e.getValue()))
.filter(e -> e.getKey() != null)
.collect(toSet());
}
void collectKeysForTesting() {
map.keySet().forEach(ref -> {
ref.clear();
ref.enqueue();
});
}
private void removeNewWeaklyReachables() {
Reference<? extends K> referent;
while ((referent = weaklyReachables.poll()) != null) {
map.remove(referent);
}
}
private static final class IdentityWeakReference<T> extends WeakReference<T> {
private final int referentHashCode;
public IdentityWeakReference(T referent) {
super(referent);
this.referentHashCode = System.identityHashCode(referent);
}
public IdentityWeakReference(T referent, ReferenceQueue<? super T> queue) {
super(referent, queue);
this.referentHashCode = System.identityHashCode(referent);
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (!(other instanceof WeakReference)) {
return false;
}
T referent = get();
if (referent == null) {
return false;
}
return referent == ((WeakReference<?>) other).get();
}
@Override
public int hashCode() {
return referentHashCode;
}
}
}
|
