-
Notifications
You must be signed in to change notification settings - Fork 1.4k
/
ThreadSafeDictionary.cs
233 lines (201 loc) · 7.08 KB
/
ThreadSafeDictionary.cs
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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
//
// Copyright (c) 2004-2019 Jaroslaw Kowalski <jaak@jkowalski.net>, Kim Christensen, Julian Verdurmen
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * Neither the name of Jaroslaw Kowalski nor the names of its
// contributors may be used to endorse or promote products derived from this
// software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
//
namespace NLog.Internal
{
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
internal class ThreadSafeDictionary<TKey, TValue> : IDictionary<TKey, TValue>
{
private readonly object _lockObject = new object();
private readonly IEqualityComparer<TKey> _comparer;
private Dictionary<TKey, TValue> _dict;
private Dictionary<TKey, TValue> _dictReadOnly; // Reset cache on change
public ThreadSafeDictionary()
:this(EqualityComparer<TKey>.Default)
{
}
public ThreadSafeDictionary(IEqualityComparer<TKey> comparer)
{
_comparer = comparer;
_dict = new Dictionary<TKey, TValue>(_comparer);
}
public ThreadSafeDictionary(ThreadSafeDictionary<TKey, TValue> source)
{
_comparer = source._comparer;
_dict = source.GetReadOnlyDict();
GetWritableDict(); // Clone
}
public TValue this[TKey key]
{
get { return GetReadOnlyDict()[key]; }
set
{
lock (_lockObject)
{
GetWritableDict()[key] = value;
}
}
}
public ICollection<TKey> Keys => GetReadOnlyDict().Keys;
public ICollection<TValue> Values => GetReadOnlyDict().Values;
public int Count => GetReadOnlyDict().Count;
public bool IsReadOnly => false;
public void Add(TKey key, TValue value)
{
lock (_lockObject)
{
GetWritableDict().Add(key, value);
}
}
public void Add(KeyValuePair<TKey, TValue> item)
{
lock (_lockObject)
{
GetWritableDict().Add(item.Key, item.Value);
}
}
public void Clear()
{
lock (_lockObject)
{
GetWritableDict(true);
}
}
public bool Contains(KeyValuePair<TKey, TValue> item)
{
return GetReadOnlyDict().Contains(item);
}
public bool ContainsKey(TKey key)
{
return GetReadOnlyDict().ContainsKey(key);
}
public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
{
((IDictionary<TKey,TValue>)GetReadOnlyDict()).CopyTo(array, arrayIndex);
}
public void CopyFrom(IDictionary<TKey, TValue> source)
{
if (!ReferenceEquals(this, source))
{
if (source?.Count > 0)
{
lock (_lockObject)
{
var destDict = GetWritableDict();
foreach (var item in source)
destDict[item.Key] = item.Value;
}
}
}
}
public bool Remove(TKey key)
{
lock (_lockObject)
{
return GetWritableDict().Remove(key);
}
}
public bool Remove(KeyValuePair<TKey, TValue> item)
{
lock (_lockObject)
{
return GetWritableDict().Remove(item);
}
}
public bool TryGetValue(TKey key, out TValue value)
{
return GetReadOnlyDict().TryGetValue(key, out value);
}
IEnumerator<KeyValuePair<TKey, TValue>> IEnumerable<KeyValuePair<TKey, TValue>>.GetEnumerator()
{
return GetReadOnlyDict().GetEnumerator();
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetReadOnlyDict().GetEnumerator();
}
public Enumerator GetEnumerator()
{
return new Enumerator(GetReadOnlyDict().GetEnumerator());
}
public struct Enumerator : IEnumerator<KeyValuePair<TKey, TValue>>
{
Dictionary<TKey, TValue>.Enumerator _enumerator;
public Enumerator(Dictionary<TKey, TValue>.Enumerator enumerator)
{
_enumerator = enumerator;
}
public KeyValuePair<TKey, TValue> Current => _enumerator.Current;
object IEnumerator.Current => _enumerator.Current;
public void Dispose()
{
_enumerator.Dispose();
}
public bool MoveNext()
{
return _enumerator.MoveNext();
}
void IEnumerator.Reset()
{
((IEnumerator)_enumerator).Reset();
}
}
private Dictionary<TKey, TValue> GetReadOnlyDict()
{
var readOnly = _dictReadOnly;
if (readOnly == null)
{
lock (_lockObject)
{
readOnly = _dictReadOnly = _dict;
}
}
return readOnly;
}
private IDictionary<TKey, TValue> GetWritableDict(bool clearDictionary = false)
{
var newDict = new Dictionary<TKey, TValue>(clearDictionary ? 0 : _dict.Count + 1, _comparer);
if (!clearDictionary)
{
// Less allocation with enumerator than Dictionary-constructor
foreach (var item in _dict)
newDict[item.Key] = item.Value;
}
_dict = newDict;
_dictReadOnly = null;
return newDict;
}
}
}