1 /* 2 * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public License 15 * along with this library; see the file COPYING.LIB. If not, write to 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 * 19 */ 20 21 // RefPtr and PassRefPtr are documented at http://webkit.org/coding/RefPtr.html 22 23 #ifndef WTF_RefPtr_h 24 #define WTF_RefPtr_h 25 26 #include <algorithm> 27 #include "wtf/FastAllocBase.h" 28 #include "wtf/HashTableDeletedValueType.h" 29 #include "wtf/PassRefPtr.h" 30 31 namespace WTF { 32 33 template<typename T> class PassRefPtr; 34 35 template<typename T> class RefPtr { 36 WTF_MAKE_FAST_ALLOCATED; 37 public: 38 ALWAYS_INLINE RefPtr() : m_ptr(0) { } 39 ALWAYS_INLINE RefPtr(T* ptr) : m_ptr(ptr) { refIfNotNull(ptr); } 40 ALWAYS_INLINE RefPtr(const RefPtr& o) : m_ptr(o.m_ptr) { refIfNotNull(m_ptr); } 41 template<typename U> RefPtr(const RefPtr<U>& o, EnsurePtrConvertibleArgDecl(U, T)) : m_ptr(o.get()) { refIfNotNull(m_ptr); } 42 43 // See comments in PassRefPtr.h for an explanation of why this takes a const reference. 44 template<typename U> RefPtr(const PassRefPtr<U>&, EnsurePtrConvertibleArgDecl(U, T)); 45 46 // Hash table deleted values, which are only constructed and never copied or destroyed. 47 RefPtr(HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) { } 48 bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); } 49 50 ALWAYS_INLINE ~RefPtr() { derefIfNotNull(m_ptr); } 51 52 T* get() const { return m_ptr; } 53 54 void clear(); 55 PassRefPtr<T> release() { PassRefPtr<T> tmp = adoptRef(m_ptr); m_ptr = 0; return tmp; } 56 57 T& operator*() const { return *m_ptr; } 58 ALWAYS_INLINE T* operator->() const { return m_ptr; } 59 60 bool operator!() const { return !m_ptr; } 61 62 // This conversion operator allows implicit conversion to bool but not to other integer types. 63 typedef T* (RefPtr::*UnspecifiedBoolType); 64 operator UnspecifiedBoolType() const { return m_ptr ? &RefPtr::m_ptr : 0; } 65 66 RefPtr& operator=(const RefPtr&); 67 RefPtr& operator=(T*); 68 RefPtr& operator=(const PassRefPtr<T>&); 69 #if !COMPILER_SUPPORTS(CXX_NULLPTR) 70 RefPtr& operator=(std::nullptr_t) { clear(); return *this; } 71 #endif 72 template<typename U> EnsurePtrConvertibleType(RefPtr<T>&, U, T) operator=(const RefPtr<U>&); 73 template<typename U> EnsurePtrConvertibleType(RefPtr<T>&, U, T) operator=(const PassRefPtr<U>&); 74 75 void swap(RefPtr&); 76 77 static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); } 78 79 private: 80 T* m_ptr; 81 }; 82 83 template<typename T> template<typename U> inline RefPtr<T>::RefPtr(const PassRefPtr<U>& o, EnsurePtrConvertibleArgDefn(U, T)) 84 : m_ptr(o.leakRef()) 85 { 86 } 87 88 template<typename T> inline void RefPtr<T>::clear() 89 { 90 T* ptr = m_ptr; 91 m_ptr = 0; 92 derefIfNotNull(ptr); 93 } 94 95 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(const RefPtr<T>& o) 96 { 97 T* optr = o.get(); 98 refIfNotNull(optr); 99 T* ptr = m_ptr; 100 m_ptr = optr; 101 derefIfNotNull(ptr); 102 return *this; 103 } 104 105 template<typename T> template<typename U> inline EnsurePtrConvertibleType(RefPtr<T>&, U, T) RefPtr<T>::operator=(const RefPtr<U>& o) 106 { 107 T* optr = o.get(); 108 refIfNotNull(optr); 109 T* ptr = m_ptr; 110 m_ptr = optr; 111 derefIfNotNull(ptr); 112 return *this; 113 } 114 115 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(T* optr) 116 { 117 refIfNotNull(optr); 118 T* ptr = m_ptr; 119 m_ptr = optr; 120 derefIfNotNull(ptr); 121 return *this; 122 } 123 124 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(const PassRefPtr<T>& o) 125 { 126 T* ptr = m_ptr; 127 m_ptr = o.leakRef(); 128 derefIfNotNull(ptr); 129 return *this; 130 } 131 132 template<typename T> template<typename U> inline EnsurePtrConvertibleType(RefPtr<T>&, U, T) RefPtr<T>::operator=(const PassRefPtr<U>& o) 133 { 134 T* ptr = m_ptr; 135 m_ptr = o.leakRef(); 136 derefIfNotNull(ptr); 137 return *this; 138 } 139 140 template<class T> inline void RefPtr<T>::swap(RefPtr<T>& o) 141 { 142 std::swap(m_ptr, o.m_ptr); 143 } 144 145 template<class T> inline void swap(RefPtr<T>& a, RefPtr<T>& b) 146 { 147 a.swap(b); 148 } 149 150 template<typename T, typename U> inline bool operator==(const RefPtr<T>& a, const RefPtr<U>& b) 151 { 152 return a.get() == b.get(); 153 } 154 155 template<typename T, typename U> inline bool operator==(const RefPtr<T>& a, U* b) 156 { 157 return a.get() == b; 158 } 159 160 template<typename T, typename U> inline bool operator==(T* a, const RefPtr<U>& b) 161 { 162 return a == b.get(); 163 } 164 165 template<typename T, typename U> inline bool operator!=(const RefPtr<T>& a, const RefPtr<U>& b) 166 { 167 return a.get() != b.get(); 168 } 169 170 template<typename T, typename U> inline bool operator!=(const RefPtr<T>& a, U* b) 171 { 172 return a.get() != b; 173 } 174 175 template<typename T, typename U> inline bool operator!=(T* a, const RefPtr<U>& b) 176 { 177 return a != b.get(); 178 } 179 180 template<typename T, typename U> inline RefPtr<T> static_pointer_cast(const RefPtr<U>& p) 181 { 182 return RefPtr<T>(static_cast<T*>(p.get())); 183 } 184 185 template<typename T> inline RefPtr<T> const_pointer_cast(const RefPtr<T>& p) 186 { 187 return RefPtr<T>(const_cast<T*>(p.get())); 188 } 189 190 template<typename T> inline T* getPtr(const RefPtr<T>& p) 191 { 192 return p.get(); 193 } 194 195 } // namespace WTF 196 197 using WTF::RefPtr; 198 using WTF::static_pointer_cast; 199 using WTF::const_pointer_cast; 200 201 #endif // WTF_RefPtr_h 202
