1 /*
2 * Copyright (C) 2007 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 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #ifndef COMPtr_h
27 #define COMPtr_h
28
29 #ifndef NOMINMAX
30 #define NOMINMAX
31 #endif
32
33 #include <guiddef.h>
34 #include <unknwn.h>
35 #include <WTF/Assertions.h>
36 #include <WTF/HashTraits.h>
37
38 typedef long HRESULT;
39
40 // FIXME: Should we put this into the WebCore namespace and use "using" on it
41 // as we do with things in WTF?
42
43 enum AdoptCOMTag { AdoptCOM };
44 enum QueryTag { Query };
45 enum CreateTag { Create };
46
47 template <typename T> class COMPtr {
48 public:
COMPtr()49 COMPtr() : m_ptr(0) { }
COMPtr(T * ptr)50 COMPtr(T* ptr) : m_ptr(ptr) { if (m_ptr) m_ptr->AddRef(); }
COMPtr(AdoptCOMTag,T * ptr)51 COMPtr(AdoptCOMTag, T* ptr) : m_ptr(ptr) { }
COMPtr(const COMPtr & o)52 COMPtr(const COMPtr& o) : m_ptr(o.m_ptr) { if (T* ptr = m_ptr) ptr->AddRef(); }
53
COMPtr(QueryTag,IUnknown * ptr)54 COMPtr(QueryTag, IUnknown* ptr) : m_ptr(copyQueryInterfaceRef(ptr)) { }
COMPtr(QueryTag,const COMPtr<U> & ptr)55 template <typename U> COMPtr(QueryTag, const COMPtr<U>& ptr) : m_ptr(copyQueryInterfaceRef(ptr.get())) { }
56
COMPtr(CreateTag,const IID & clsid)57 COMPtr(CreateTag, const IID& clsid) : m_ptr(createInstance(clsid)) { }
58
59 // Hash table deleted values, which are only constructed and never copied or destroyed.
COMPtr(WTF::HashTableDeletedValueType)60 COMPtr(WTF::HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) { }
isHashTableDeletedValue()61 bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); }
62
~COMPtr()63 ~COMPtr() { if (m_ptr) m_ptr->Release(); }
64
get()65 T* get() const { return m_ptr; }
releaseRef()66 T* releaseRef() { T* tmp = m_ptr; m_ptr = 0; return tmp; }
67
68 T& operator*() const { return *m_ptr; }
69 T* operator->() const { return m_ptr; }
70
71 T** operator&() { ASSERT(!m_ptr); return &m_ptr; }
72
73 bool operator!() const { return !m_ptr; }
74
75 // This conversion operator allows implicit conversion to bool but not to other integer types.
76 typedef T* (COMPtr::*UnspecifiedBoolType)() const;
UnspecifiedBoolType()77 operator UnspecifiedBoolType() const { return m_ptr ? &COMPtr::get : 0; }
78
79 COMPtr& operator=(const COMPtr&);
80 COMPtr& operator=(T*);
81 template <typename U> COMPtr& operator=(const COMPtr<U>&);
82
query(IUnknown * ptr)83 void query(IUnknown* ptr) { adoptRef(copyQueryInterfaceRef(ptr)); }
query(const COMPtr<U> & ptr)84 template <typename U> void query(const COMPtr<U>& ptr) { query(ptr.get()); }
85
create(const IID & clsid)86 void create(const IID& clsid) { adoptRef(createInstance(clsid)); }
87
88 template <typename U> HRESULT copyRefTo(U**);
89 void adoptRef(T*);
90
91 private:
92 static T* copyQueryInterfaceRef(IUnknown*);
93 static T* createInstance(const IID& clsid);
hashTableDeletedValue()94 static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); }
95
96 T* m_ptr;
97 };
98
createInstance(const IID & clsid)99 template <typename T> inline T* COMPtr<T>::createInstance(const IID& clsid)
100 {
101 T* result;
102 if (FAILED(CoCreateInstance(clsid, 0, CLSCTX_ALL, __uuidof(result), reinterpret_cast<void**>(&result))))
103 return 0;
104 return result;
105 }
106
copyQueryInterfaceRef(IUnknown * ptr)107 template <typename T> inline T* COMPtr<T>::copyQueryInterfaceRef(IUnknown* ptr)
108 {
109 if (!ptr)
110 return 0;
111 T* result;
112 if (FAILED(ptr->QueryInterface(&result)))
113 return 0;
114 return result;
115 }
116
copyRefTo(U ** ptr)117 template <typename T> template <typename U> inline HRESULT COMPtr<T>::copyRefTo(U** ptr)
118 {
119 if (!ptr)
120 return E_POINTER;
121 *ptr = m_ptr;
122 if (m_ptr)
123 m_ptr->AddRef();
124 return S_OK;
125 }
126
adoptRef(T * ptr)127 template <typename T> inline void COMPtr<T>::adoptRef(T *ptr)
128 {
129 if (m_ptr)
130 m_ptr->Release();
131 m_ptr = ptr;
132 }
133
134 template <typename T> inline COMPtr<T>& COMPtr<T>::operator=(const COMPtr<T>& o)
135 {
136 T* optr = o.get();
137 if (optr)
138 optr->AddRef();
139 T* ptr = m_ptr;
140 m_ptr = optr;
141 if (ptr)
142 ptr->Release();
143 return *this;
144 }
145
146 template <typename T> template <typename U> inline COMPtr<T>& COMPtr<T>::operator=(const COMPtr<U>& o)
147 {
148 T* optr = o.get();
149 if (optr)
150 optr->AddRef();
151 T* ptr = m_ptr;
152 m_ptr = optr;
153 if (ptr)
154 ptr->Release();
155 return *this;
156 }
157
158 template <typename T> inline COMPtr<T>& COMPtr<T>::operator=(T* optr)
159 {
160 if (optr)
161 optr->AddRef();
162 T* ptr = m_ptr;
163 m_ptr = optr;
164 if (ptr)
165 ptr->Release();
166 return *this;
167 }
168
169 template <typename T, typename U> inline bool operator==(const COMPtr<T>& a, const COMPtr<U>& b)
170 {
171 return a.get() == b.get();
172 }
173
174 template <typename T, typename U> inline bool operator==(const COMPtr<T>& a, U* b)
175 {
176 return a.get() == b;
177 }
178
179 template <typename T, typename U> inline bool operator==(T* a, const COMPtr<U>& b)
180 {
181 return a == b.get();
182 }
183
184 template <typename T, typename U> inline bool operator!=(const COMPtr<T>& a, const COMPtr<U>& b)
185 {
186 return a.get() != b.get();
187 }
188
189 template <typename T, typename U> inline bool operator!=(const COMPtr<T>& a, U* b)
190 {
191 return a.get() != b;
192 }
193
194 template <typename T, typename U> inline bool operator!=(T* a, const COMPtr<U>& b)
195 {
196 return a != b.get();
197 }
198
199 namespace WTF {
200
201 template<typename P> struct HashTraits<COMPtr<P> > : GenericHashTraits<COMPtr<P> > {
202 static const bool emptyValueIsZero = true;
203 static void constructDeletedValue(COMPtr<P>& slot) { slot.releaseRef(); *&slot = reinterpret_cast<P*>(-1); }
204 static bool isDeletedValue(const COMPtr<P>& value) { return value == reinterpret_cast<P*>(-1); }
205 };
206
207 template<typename P> struct PtrHash<COMPtr<P> > : PtrHash<P*> {
208 using PtrHash<P*>::hash;
209 static unsigned hash(const COMPtr<P>& key) { return hash(key.get()); }
210 using PtrHash<P*>::equal;
211 static bool equal(const COMPtr<P>& a, const COMPtr<P>& b) { return a == b; }
212 static bool equal(P* a, const COMPtr<P>& b) { return a == b; }
213 static bool equal(const COMPtr<P>& a, P* b) { return a == b; }
214 };
215
216 template<typename P> struct DefaultHash<COMPtr<P> > { typedef PtrHash<COMPtr<P> > Hash; };
217 }
218
219 #endif
220