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40****************************************************************************/
41
42#ifndef QSHAREDDATA_H
43#define QSHAREDDATA_H
44
45#include <QtCore/qglobal.h>
46#include <QtCore/qatomic.h>
47
48QT_BEGIN_HEADER
49
50QT_BEGIN_NAMESPACE
51
52QT_MODULE(Core)
53
54template <class T> class QSharedDataPointer;
55
56class Q_CORE_EXPORT QSharedData
57{
58public:
59 mutable QAtomicInt ref;
60
61 inline QSharedData() : ref(0) { }
62 inline QSharedData(const QSharedData &) : ref(0) { }
63
64private:
65 // using the assignment operator would lead to corruption in the ref-counting
66 QSharedData &operator=(const QSharedData &);
67};
68
69template <class T> class QSharedDataPointer
70{
71public:
72 typedef T Type;
73 typedef T *pointer;
74
75 inline void detach() { if (d && d->ref != 1) detach_helper(); }
76 inline T &operator*() { detach(); return *d; }
77 inline const T &operator*() const { return *d; }
78 inline T *operator->() { detach(); return d; }
79 inline const T *operator->() const { return d; }
80 inline operator T *() { detach(); return d; }
81 inline operator const T *() const { return d; }
82 inline T *data() { detach(); return d; }
83 inline const T *data() const { return d; }
84 inline const T *constData() const { return d; }
85
86 inline bool operator==(const QSharedDataPointer<T> &other) const { return d == other.d; }
87 inline bool operator!=(const QSharedDataPointer<T> &other) const { return d != other.d; }
88
89 inline QSharedDataPointer() { d = 0; }
90 inline ~QSharedDataPointer() { if (d && !d->ref.deref()) delete d; }
91
92 explicit QSharedDataPointer(T *data);
93 inline QSharedDataPointer(const QSharedDataPointer<T> &o) : d(o.d) { if (d) d->ref.ref(); }
94 inline QSharedDataPointer<T> & operator=(const QSharedDataPointer<T> &o) {
95 if (o.d != d) {
96 if (o.d)
97 o.d->ref.ref();
98 T *old = d;
99 d = o.d;
100 if (old && !old->ref.deref())
101 delete old;
102 }
103 return *this;
104 }
105 inline QSharedDataPointer &operator=(T *o) {
106 if (o != d) {
107 if (o)
108 o->ref.ref();
109 T *old = d;
110 d = o;
111 if (old && !old->ref.deref())
112 delete old;
113 }
114 return *this;
115 }
116#ifdef Q_COMPILER_RVALUE_REFS
117 QSharedDataPointer(QSharedDataPointer &&o) : d(o.d) { o.d = 0; }
118 inline QSharedDataPointer<T> &operator=(QSharedDataPointer<T> &&other)
119 { qSwap(d, other.d); return *this; }
120#endif
121
122 inline bool operator!() const { return !d; }
123
124 inline void swap(QSharedDataPointer &other)
125 { qSwap(d, other.d); }
126
127protected:
128 T *clone();
129
130private:
131 void detach_helper();
132
133 T *d;
134};
135
136template <class T> class QExplicitlySharedDataPointer
137{
138public:
139 typedef T Type;
140 typedef T *pointer;
141
142 inline T &operator*() const { return *d; }
143 inline T *operator->() { return d; }
144 inline T *operator->() const { return d; }
145 inline T *data() const { return d; }
146 inline const T *constData() const { return d; }
147
148 inline void detach() { if (d && d->ref != 1) detach_helper(); }
149
150 inline void reset()
151 {
152 if(d && !d->ref.deref())
153 delete d;
154
155 d = 0;
156 }
157
158 inline operator bool () const { return d != 0; }
159
160 inline bool operator==(const QExplicitlySharedDataPointer<T> &other) const { return d == other.d; }
161 inline bool operator!=(const QExplicitlySharedDataPointer<T> &other) const { return d != other.d; }
162 inline bool operator==(const T *ptr) const { return d == ptr; }
163 inline bool operator!=(const T *ptr) const { return d != ptr; }
164
165 inline QExplicitlySharedDataPointer() { d = 0; }
166 inline ~QExplicitlySharedDataPointer() { if (d && !d->ref.deref()) delete d; }
167
168 explicit QExplicitlySharedDataPointer(T *data);
169 inline QExplicitlySharedDataPointer(const QExplicitlySharedDataPointer<T> &o) : d(o.d) { if (d) d->ref.ref(); }
170
171 template<class X>
172 inline QExplicitlySharedDataPointer(const QExplicitlySharedDataPointer<X> &o) : d(static_cast<T *>(o.data()))
173 {
174 if(d)
175 d->ref.ref();
176 }
177
178 inline QExplicitlySharedDataPointer<T> & operator=(const QExplicitlySharedDataPointer<T> &o) {
179 if (o.d != d) {
180 if (o.d)
181 o.d->ref.ref();
182 T *old = d;
183 d = o.d;
184 if (old && !old->ref.deref())
185 delete old;
186 }
187 return *this;
188 }
189 inline QExplicitlySharedDataPointer &operator=(T *o) {
190 if (o != d) {
191 if (o)
192 o->ref.ref();
193 T *old = d;
194 d = o;
195 if (old && !old->ref.deref())
196 delete old;
197 }
198 return *this;
199 }
200#ifdef Q_COMPILER_RVALUE_REFS
201 inline QExplicitlySharedDataPointer(QExplicitlySharedDataPointer &&o) : d(o.d) { o.d = 0; }
202 inline QExplicitlySharedDataPointer<T> &operator=(QExplicitlySharedDataPointer<T> &&other)
203 { qSwap(d, other.d); return *this; }
204#endif
205
206 inline bool operator!() const { return !d; }
207
208 inline void swap(QExplicitlySharedDataPointer &other)
209 { qSwap(d, other.d); }
210
211protected:
212 T *clone();
213
214private:
215 void detach_helper();
216
217 T *d;
218};
219
220template <class T>
221Q_INLINE_TEMPLATE QSharedDataPointer<T>::QSharedDataPointer(T *adata) : d(adata)
222{ if (d) d->ref.ref(); }
223
224template <class T>
225Q_INLINE_TEMPLATE T *QSharedDataPointer<T>::clone()
226{
227 return new T(*d);
228}
229
230template <class T>
231Q_OUTOFLINE_TEMPLATE void QSharedDataPointer<T>::detach_helper()
232{
233 T *x = clone();
234 x->ref.ref();
235 if (!d->ref.deref())
236 delete d;
237 d = x;
238}
239
240template <class T>
241Q_INLINE_TEMPLATE T *QExplicitlySharedDataPointer<T>::clone()
242{
243 return new T(*d);
244}
245
246template <class T>
247Q_OUTOFLINE_TEMPLATE void QExplicitlySharedDataPointer<T>::detach_helper()
248{
249 T *x = clone();
250 x->ref.ref();
251 if (!d->ref.deref())
252 delete d;
253 d = x;
254}
255
256template <class T>
257Q_INLINE_TEMPLATE QExplicitlySharedDataPointer<T>::QExplicitlySharedDataPointer(T *adata) : d(adata)
258{ if (d) d->ref.ref(); }
259
260template <class T>
261Q_INLINE_TEMPLATE void qSwap(QSharedDataPointer<T> &p1, QSharedDataPointer<T> &p2)
262{ p1.swap(p2); }
263
264template <class T>
265Q_INLINE_TEMPLATE void qSwap(QExplicitlySharedDataPointer<T> &p1, QExplicitlySharedDataPointer<T> &p2)
266{ p1.swap(p2); }
267
268#ifndef QT_NO_STL
269QT_END_NAMESPACE
270namespace std {
271 template <class T>
272 Q_INLINE_TEMPLATE void swap(QT_PREPEND_NAMESPACE(QSharedDataPointer)<T> &p1, QT_PREPEND_NAMESPACE(QSharedDataPointer)<T> &p2)
273 { p1.swap(p2); }
274
275 template <class T>
276 Q_INLINE_TEMPLATE void swap(QT_PREPEND_NAMESPACE(QExplicitlySharedDataPointer)<T> &p1, QT_PREPEND_NAMESPACE(QExplicitlySharedDataPointer)<T> &p2)
277 { p1.swap(p2); }
278}
279QT_BEGIN_NAMESPACE
280#endif
281
282QT_END_NAMESPACE
283
284QT_END_HEADER
285
286#endif // QSHAREDDATA_H
287