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
|
/**
* @file llindexedqueue.h
* @brief An indexed FIFO queue, where only one element with each key
* can be in the queue.
*
* $LicenseInfo:firstyear=2003&license=viewergpl$
*
* Copyright (c) 2003-2009, Linden Research, Inc.
*
* Second Life Viewer Source Code
* The source code in this file ("Source Code") is provided by Linden Lab
* to you under the terms of the GNU General Public License, version 2.0
* ("GPL"), unless you have obtained a separate licensing agreement
* ("Other License"), formally executed by you and Linden Lab. Terms of
* the GPL can be found in doc/GPL-license.txt in this distribution, or
* online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
*
* There are special exceptions to the terms and conditions of the GPL as
* it is applied to this Source Code. View the full text of the exception
* in the file doc/FLOSS-exception.txt in this software distribution, or
* online at http://secondlifegrid.net/programs/open_source/licensing/flossexception
*
* By copying, modifying or distributing this software, you acknowledge
* that you have read and understood your obligations described above,
* and agree to abide by those obligations.
*
* ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
* WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
* COMPLETENESS OR PERFORMANCE.
* $/LicenseInfo$
*/
#ifndef LL_LLINDEXEDQUEUE_H
#define LL_LLINDEXEDQUEUE_H
// An indexed FIFO queue, where only one element with each key can be in the queue.
// This is ONLY used in the interest list, you'll probably want to review this code
// carefully if you want to use it elsewhere - Doug
template <typename Type>
class LLIndexedQueue
{
protected:
typedef std::deque<Type> type_deque;
type_deque mQueue;
std::set<Type> mKeySet;
public:
LLIndexedQueue() {}
// move_if_there is an O(n) operation
bool push_back(const Type &value, bool move_if_there = false)
{
if (mKeySet.find(value) != mKeySet.end())
{
// Already on the queue
if (move_if_there)
{
// Remove the existing entry.
typename type_deque::iterator it;
for (it = mQueue.begin(); it != mQueue.end(); ++it)
{
if (*it == value)
{
break;
}
}
// This HAS to succeed, otherwise there's a serious bug in the keyset implementation
// (although this isn't thread safe, at all)
mQueue.erase(it);
}
else
{
// We're not moving it, leave it alone
return false;
}
}
else
{
// Doesn't exist, add it to the key set
mKeySet.insert(value);
}
mQueue.push_back(value);
// We succeeded in adding the new element.
return true;
}
bool push_front(const Type &value, bool move_if_there = false)
{
if (mKeySet.find(value) != mKeySet.end())
{
// Already on the queue
if (move_if_there)
{
// Remove the existing entry.
typename type_deque::iterator it;
for (it = mQueue.begin(); it != mQueue.end(); ++it)
{
if (*it == value)
{
break;
}
}
// This HAS to succeed, otherwise there's a serious bug in the keyset implementation
// (although this isn't thread safe, at all)
mQueue.erase(it);
}
else
{
// We're not moving it, leave it alone
return false;
}
}
else
{
// Doesn't exist, add it to the key set
mKeySet.insert(value);
}
mQueue.push_front(value);
return true;
}
void pop()
{
Type value = mQueue.front();
mKeySet.erase(value);
mQueue.pop_front();
}
Type &front()
{
return mQueue.front();
}
S32 size() const
{
return mQueue.size();
}
bool empty() const
{
return mQueue.empty();
}
void clear()
{
// Clear out all elements on the queue
mQueue.clear();
mKeySet.clear();
}
};
#endif // LL_LLINDEXEDQUEUE_H
|
