1/*
2 * Copyright (C) 2005, 2006, 2007, 2010 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef JSRetainPtr_h
30#define JSRetainPtr_h
31
32#include <JavaScriptCore/JSContextRef.h>
33#include <JavaScriptCore/JSStringRef.h>
34#include <algorithm>
35
36inline void JSRetain(JSStringRef string) { JSStringRetain(string); }
37inline void JSRelease(JSStringRef string) { JSStringRelease(string); }
38inline void JSRetain(JSGlobalContextRef context) { JSGlobalContextRetain(context); }
39inline void JSRelease(JSGlobalContextRef context) { JSGlobalContextRelease(context); }
40
41enum AdoptTag { Adopt };
42
43template<typename T> class JSRetainPtr {
44public:
45    JSRetainPtr() : m_ptr(0) { }
46    JSRetainPtr(T ptr) : m_ptr(ptr) { if (ptr) JSRetain(ptr); }
47    JSRetainPtr(AdoptTag, T ptr) : m_ptr(ptr) { }
48    JSRetainPtr(const JSRetainPtr&);
49    template<typename U> JSRetainPtr(const JSRetainPtr<U>&);
50    ~JSRetainPtr();
51
52    T get() const { return m_ptr; }
53
54    void clear();
55    T leakRef();
56
57    T operator->() const { return m_ptr; }
58
59    bool operator!() const { return !m_ptr; }
60
61    // This conversion operator allows implicit conversion to bool but not to other integer types.
62    typedef T JSRetainPtr::*UnspecifiedBoolType;
63    operator UnspecifiedBoolType() const { return m_ptr ? &JSRetainPtr::m_ptr : 0; }
64
65    JSRetainPtr& operator=(const JSRetainPtr&);
66    template<typename U> JSRetainPtr& operator=(const JSRetainPtr<U>&);
67    JSRetainPtr& operator=(T);
68    template<typename U> JSRetainPtr& operator=(U*);
69
70    void adopt(T);
71
72    void swap(JSRetainPtr&);
73
74private:
75    T m_ptr;
76};
77
78template<typename T> inline JSRetainPtr<T>::JSRetainPtr(const JSRetainPtr& o)
79    : m_ptr(o.m_ptr)
80{
81    if (m_ptr)
82        JSRetain(m_ptr);
83}
84
85template<typename T> template<typename U> inline JSRetainPtr<T>::JSRetainPtr(const JSRetainPtr<U>& o)
86    : m_ptr(o.get())
87{
88    if (m_ptr)
89        JSRetain(m_ptr);
90}
91
92template<typename T> inline JSRetainPtr<T>::~JSRetainPtr()
93{
94    if (m_ptr)
95        JSRelease(m_ptr);
96}
97
98template<typename T> inline void JSRetainPtr<T>::clear()
99{
100    if (T ptr = m_ptr) {
101        m_ptr = 0;
102        JSRelease(ptr);
103    }
104}
105
106template<typename T> inline T JSRetainPtr<T>::leakRef()
107{
108    T ptr = m_ptr;
109    m_ptr = 0;
110    return ptr;
111}
112
113template<typename T> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(const JSRetainPtr<T>& o)
114{
115    T optr = o.get();
116    if (optr)
117        JSRetain(optr);
118    T ptr = m_ptr;
119    m_ptr = optr;
120    if (ptr)
121        JSRelease(ptr);
122    return *this;
123}
124
125template<typename T> template<typename U> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(const JSRetainPtr<U>& o)
126{
127    T optr = o.get();
128    if (optr)
129        JSRetain(optr);
130    T ptr = m_ptr;
131    m_ptr = optr;
132    if (ptr)
133        JSRelease(ptr);
134    return *this;
135}
136
137template<typename T> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(T optr)
138{
139    if (optr)
140        JSRetain(optr);
141    T ptr = m_ptr;
142    m_ptr = optr;
143    if (ptr)
144        JSRelease(ptr);
145    return *this;
146}
147
148template<typename T> inline void JSRetainPtr<T>::adopt(T optr)
149{
150    T ptr = m_ptr;
151    m_ptr = optr;
152    if (ptr)
153        JSRelease(ptr);
154}
155
156template<typename T> template<typename U> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(U* optr)
157{
158    if (optr)
159        JSRetain(optr);
160    T ptr = m_ptr;
161    m_ptr = optr;
162    if (ptr)
163        JSRelease(ptr);
164    return *this;
165}
166
167template<typename T> inline void JSRetainPtr<T>::swap(JSRetainPtr<T>& o)
168{
169    std::swap(m_ptr, o.m_ptr);
170}
171
172template<typename T> inline void swap(JSRetainPtr<T>& a, JSRetainPtr<T>& b)
173{
174    a.swap(b);
175}
176
177template<typename T, typename U> inline bool operator==(const JSRetainPtr<T>& a, const JSRetainPtr<U>& b)
178{
179    return a.get() == b.get();
180}
181
182template<typename T, typename U> inline bool operator==(const JSRetainPtr<T>& a, U* b)
183{
184    return a.get() == b;
185}
186
187template<typename T, typename U> inline bool operator==(T* a, const JSRetainPtr<U>& b)
188{
189    return a == b.get();
190}
191
192template<typename T, typename U> inline bool operator!=(const JSRetainPtr<T>& a, const JSRetainPtr<U>& b)
193{
194    return a.get() != b.get();
195}
196
197template<typename T, typename U> inline bool operator!=(const JSRetainPtr<T>& a, U* b)
198{
199    return a.get() != b;
200}
201
202template<typename T, typename U> inline bool operator!=(T* a, const JSRetainPtr<U>& b)
203{
204    return a != b.get();
205}
206
207
208#endif // JSRetainPtr_h
209