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
|
/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** 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 Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef QCACHE_H
#define QCACHE_H
#include <QtCore/qhash.h>
QT_BEGIN_HEADER
QT_BEGIN_NAMESPACE
QT_MODULE(Core)
template <class Key, class T>
class QCache
{
struct Node {
inline Node() : keyPtr(0) {}
inline Node(T *data, int cost)
: keyPtr(0), t(data), c(cost), p(0), n(0) {}
const Key *keyPtr; T *t; int c; Node *p,*n;
};
Node *f, *l;
QHash<Key, Node> hash;
void *unused; // ### Qt5: remove
int mx, total;
inline void unlink(Node &n) {
if (n.p) n.p->n = n.n;
if (n.n) n.n->p = n.p;
if (l == &n) l = n.p;
if (f == &n) f = n.n;
total -= n.c;
T *obj = n.t;
hash.remove(*n.keyPtr);
delete obj;
}
inline T *relink(const Key &key) {
typename QHash<Key, Node>::iterator i = hash.find(key);
if (typename QHash<Key, Node>::const_iterator(i) == hash.constEnd())
return 0;
Node &n = *i;
if (f != &n) {
if (n.p) n.p->n = n.n;
if (n.n) n.n->p = n.p;
if (l == &n) l = n.p;
n.p = 0;
n.n = f;
f->p = &n;
f = &n;
}
return n.t;
}
Q_DISABLE_COPY(QCache)
public:
inline explicit QCache(int maxCost = 100);
#ifdef QT3_SUPPORT
inline QT3_SUPPORT_CONSTRUCTOR QCache(int maxCost, int /* dummy */)
: f(0), l(0), mx(maxCost), total(0) {}
#endif
inline ~QCache() { clear(); }
inline int maxCost() const { return mx; }
void setMaxCost(int m);
inline int totalCost() const { return total; }
inline int size() const { return hash.size(); }
inline int count() const { return hash.size(); }
inline bool isEmpty() const { return hash.isEmpty(); }
inline QList<Key> keys() const { return hash.keys(); }
void clear();
bool insert(const Key &key, T *object, int cost = 1);
T *object(const Key &key) const;
inline bool contains(const Key &key) const { return hash.contains(key); }
T *operator[](const Key &key) const;
bool remove(const Key &key);
T *take(const Key &key);
private:
void trim(int m);
#ifdef QT3_SUPPORT
inline QT3_SUPPORT T *find(const Key &key) const { return object(key); }
#endif
};
template <class Key, class T>
inline QCache<Key, T>::QCache(int amaxCost)
: f(0), l(0), unused(0), mx(amaxCost), total(0) {}
template <class Key, class T>
inline void QCache<Key,T>::clear()
{ while (f) { delete f->t; f = f->n; }
hash.clear(); l = 0; total = 0; }
template <class Key, class T>
inline void QCache<Key,T>::setMaxCost(int m)
{ mx = m; trim(mx); }
template <class Key, class T>
inline T *QCache<Key,T>::object(const Key &key) const
{ return const_cast<QCache<Key,T>*>(this)->relink(key); }
template <class Key, class T>
inline T *QCache<Key,T>::operator[](const Key &key) const
{ return object(key); }
template <class Key, class T>
inline bool QCache<Key,T>::remove(const Key &key)
{
typename QHash<Key, Node>::iterator i = hash.find(key);
if (typename QHash<Key, Node>::const_iterator(i) == hash.constEnd()) {
return false;
} else {
unlink(*i);
return true;
}
}
template <class Key, class T>
inline T *QCache<Key,T>::take(const Key &key)
{
typename QHash<Key, Node>::iterator i = hash.find(key);
if (i == hash.end())
return 0;
Node &n = *i;
T *t = n.t;
n.t = 0;
unlink(n);
return t;
}
template <class Key, class T>
bool QCache<Key,T>::insert(const Key &akey, T *aobject, int acost)
{
remove(akey);
if (acost > mx) {
delete aobject;
return false;
}
trim(mx - acost);
Node sn(aobject, acost);
typename QHash<Key, Node>::iterator i = hash.insert(akey, sn);
total += acost;
Node *n = &i.value();
n->keyPtr = &i.key();
if (f) f->p = n;
n->n = f;
f = n;
if (!l) l = f;
return true;
}
template <class Key, class T>
void QCache<Key,T>::trim(int m)
{
Node *n = l;
while (n && total > m) {
Node *u = n;
n = n->p;
unlink(*u);
}
}
QT_END_NAMESPACE
QT_END_HEADER
#endif // QCACHE_H
|
