summaryrefslogtreecommitdiffstats
path: root/src/corelib/tools/qshareddata.h
blob: 7e9934d552f89365533feb8b511949c1d9ca3549 (plain)
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
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** 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, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef QSHAREDDATA_H
#define QSHAREDDATA_H

#include <QtCore/qglobal.h>
#include <QtCore/qatomic.h>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Core)

template <class T> class QSharedDataPointer;

class Q_CORE_EXPORT QSharedData
{
public:
    mutable QAtomicInt ref;

    inline QSharedData() : ref(0) { }
    inline QSharedData(const QSharedData &) : ref(0) { }

private:
    // using the assignment operator would lead to corruption in the ref-counting
    QSharedData &operator=(const QSharedData &);
};

template <class T> class QSharedDataPointer
{
public:
    typedef T Type;
    typedef T *pointer;

    inline void detach() { if (d && d->ref != 1) detach_helper(); }
    inline T &operator*() { detach(); return *d; }
    inline const T &operator*() const { return *d; }
    inline T *operator->() { detach(); return d; }
    inline const T *operator->() const { return d; }
    inline operator T *() { detach(); return d; }
    inline operator const T *() const { return d; }
    inline T *data() { detach(); return d; }
    inline const T *data() const { return d; }
    inline const T *constData() const { return d; }

    inline bool operator==(const QSharedDataPointer<T> &other) const { return d == other.d; }
    inline bool operator!=(const QSharedDataPointer<T> &other) const { return d != other.d; }

    inline QSharedDataPointer() { d = 0; }
    inline ~QSharedDataPointer() { if (d && !d->ref.deref()) delete d; }

    explicit QSharedDataPointer(T *data);
    inline QSharedDataPointer(const QSharedDataPointer<T> &o) : d(o.d) { if (d) d->ref.ref(); }
    inline QSharedDataPointer<T> & operator=(const QSharedDataPointer<T> &o) {
        if (o.d != d) {
            if (o.d)
                o.d->ref.ref();
            if (d && !d->ref.deref())
                delete d;
            d = o.d;
        }
        return *this;
    }
    inline QSharedDataPointer &operator=(T *o) {
        if (o != d) {
            if (o)
                o->ref.ref();
            if (d && !d->ref.deref())
                delete d;
            d = o;
        }
        return *this;
    }

    inline bool operator!() const { return !d; }

    inline void swap(QSharedDataPointer &other)
    { qSwap(d, other.d); }

protected:
    T *clone();

private:
    void detach_helper();

    T *d;
};

template <class T> class QExplicitlySharedDataPointer
{
public:
    typedef T Type;
    typedef T *pointer;

    inline T &operator*() const { return *d; }
    inline T *operator->() { return d; }
    inline T *operator->() const { return d; }
    inline T *data() const { return d; }
    inline const T *constData() const { return d; }

    inline void detach() { if (d && d->ref != 1) detach_helper(); }

    inline void reset()
    {
        if(d && !d->ref.deref())
            delete d;

        d = 0;
    }

    inline operator bool () const { return d != 0; }

    inline bool operator==(const QExplicitlySharedDataPointer<T> &other) const { return d == other.d; }
    inline bool operator!=(const QExplicitlySharedDataPointer<T> &other) const { return d != other.d; }
    inline bool operator==(const T *ptr) const { return d == ptr; }
    inline bool operator!=(const T *ptr) const { return d != ptr; }

    inline QExplicitlySharedDataPointer() { d = 0; }
    inline ~QExplicitlySharedDataPointer() { if (d && !d->ref.deref()) delete d; }

    explicit QExplicitlySharedDataPointer(T *data);
    inline QExplicitlySharedDataPointer(const QExplicitlySharedDataPointer<T> &o) : d(o.d) { if (d) d->ref.ref(); }

#ifndef QT_NO_MEMBER_TEMPLATES
    template<class X>
    inline QExplicitlySharedDataPointer(const QExplicitlySharedDataPointer<X> &o) : d(static_cast<T *>(o.data()))
    {
        if(d)
            d->ref.ref();
    }
#endif

    inline QExplicitlySharedDataPointer<T> & operator=(const QExplicitlySharedDataPointer<T> &o) {
        if (o.d != d) {
            if (o.d)
                o.d->ref.ref();
            if (d && !d->ref.deref())
                delete d;
            d = o.d;
        }
        return *this;
    }
    inline QExplicitlySharedDataPointer &operator=(T *o) {
        if (o != d) {
            if (o)
                o->ref.ref();
            if (d && !d->ref.deref())
                delete d;
            d = o;
        }
        return *this;
    }

    inline bool operator!() const { return !d; }

    inline void swap(QExplicitlySharedDataPointer &other)
    { qSwap(d, other.d); }

protected:
    T *clone();

private:
    void detach_helper();

    T *d;
};

template <class T>
Q_INLINE_TEMPLATE QSharedDataPointer<T>::QSharedDataPointer(T *adata) : d(adata)
{ if (d) d->ref.ref(); }

template <class T>
Q_INLINE_TEMPLATE T *QSharedDataPointer<T>::clone()
{
    return new T(*d);
}

template <class T>
Q_OUTOFLINE_TEMPLATE void QSharedDataPointer<T>::detach_helper()
{
    T *x = clone();
    x->ref.ref();
    if (!d->ref.deref())
        delete d;
    d = x;
}

template <class T>
Q_INLINE_TEMPLATE T *QExplicitlySharedDataPointer<T>::clone()
{
    return new T(*d);
}

template <class T>
Q_OUTOFLINE_TEMPLATE void QExplicitlySharedDataPointer<T>::detach_helper()
{
    T *x = clone();
    x->ref.ref();
    if (!d->ref.deref())
        delete d;
    d = x;
}

template <class T>
Q_INLINE_TEMPLATE QExplicitlySharedDataPointer<T>::QExplicitlySharedDataPointer(T *adata) : d(adata)
{ if (d) d->ref.ref(); }

template <class T>
Q_INLINE_TEMPLATE void qSwap(QSharedDataPointer<T> &p1, QSharedDataPointer<T> &p2)
{ p1.swap(p2); }

template <class T>
Q_INLINE_TEMPLATE void qSwap(QExplicitlySharedDataPointer<T> &p1, QExplicitlySharedDataPointer<T> &p2)
{ p1.swap(p2); }

QT_END_NAMESPACE

QT_END_HEADER

#endif // QSHAREDDATA_H