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) 2021 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt VS Tools.
**
** $QT_BEGIN_LICENSE:GPL-EXCEPT$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
namespace QtVsTools
{
public class PriorityQueue<T, TPriority> : BasePriorityQueue<T, TPriority>
where TPriority : IComparable<TPriority>
{
public PriorityQueue() : base()
{ }
public PriorityQueue(Func<T, object> getItemKey) : base(getItemKey)
{ }
public new void Enqueue(T item, TPriority priority)
{
base.Enqueue(item, priority);
}
}
public abstract class BasePriorityQueue<T, TPriority> : Concurrent, IEnumerable<T>
where TPriority : IComparable<TPriority>
{
SortedDictionary<TPriority, T> ItemsByPriority { get; }
Dictionary<object, TPriority> ItemPriority { get; }
T Head { get; set; }
public int Count { get; private set; }
public bool IsEmpty => (Count == 0);
IEnumerable<T> Items => ThreadSafe(() => ItemsByPriority.Values.ToList());
IEnumerator<T> IEnumerable<T>.GetEnumerator() => Items.GetEnumerator();
IEnumerator IEnumerable.GetEnumerator() => Items.GetEnumerator();
Func<T, object> GetItemKey { get; }
public BasePriorityQueue() : this(x => x)
{ }
public BasePriorityQueue(Func<T, object> getItemKey)
{
ItemsByPriority = new SortedDictionary<TPriority, T>();
ItemPriority = new Dictionary<object, TPriority>();
Head = default(T);
Count = 0;
GetItemKey = getItemKey;
}
public void Clear()
{
lock (CriticalSection) {
if (Count == 0)
return;
ItemsByPriority.Clear();
ItemPriority.Clear();
Head = default(T);
Count = 0;
}
}
public bool Contains(T item)
{
lock (CriticalSection) {
return ItemPriority.ContainsKey(GetItemKey(item));
}
}
// Base Enqueue() is protected to allow specialized implementations to
// hide the concept of priority (e.g. PunisherQueue).
//
protected void Enqueue(T item, TPriority priority)
{
if (item == null)
throw new InvalidOperationException("Item cannot be null.");
lock (CriticalSection) {
T oldItem;
if (ItemsByPriority.TryGetValue(priority, out oldItem) && !item.Equals(oldItem))
throw new InvalidOperationException("An item with the same priority exists.");
TPriority oldPriority;
if (ItemPriority.TryGetValue(GetItemKey(item), out oldPriority)) {
ItemsByPriority.Remove(oldPriority);
--Count;
}
ItemPriority[GetItemKey(item)] = priority;
ItemsByPriority[priority] = item;
Head = ItemsByPriority.First().Value;
++Count;
}
}
public bool TryPeek(out T result)
{
lock (CriticalSection) {
result = Head;
return Count > 0;
}
}
public T Peek()
{
lock (CriticalSection) {
T result;
if (!TryPeek(out result))
throw new InvalidOperationException("Queue is empty.");
return result;
}
}
public void Remove(T item)
{
lock (CriticalSection) {
object key = GetItemKey(item);
if (key == null)
return;
ItemsByPriority.Remove(ItemPriority[key]);
ItemPriority.Remove(key);
--Count;
if (key == GetItemKey(Head)) {
if (IsEmpty)
Head = default(T);
else
Head = ItemsByPriority.First().Value;
}
}
}
public bool TryDequeue(out T result)
{
lock (CriticalSection) {
result = Head;
if (IsEmpty)
return false;
Remove(Head);
return true;
}
}
public T Dequeue()
{
lock (CriticalSection) {
T result;
if (!TryDequeue(out result))
throw new InvalidOperationException("Queue is empty.");
return result;
}
}
}
}
|
