1 /*
2 * Copyright (C) 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 * 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 <unknwn.h>
34 #include <wtf/Assertions.h>
35 #include <wtf/HashTraits.h>
36
37 #if !OS(WINCE)
38 #include <guiddef.h>
39 #endif
40
41 typedef long HRESULT;
42
43 // FIXME: Should we put this into the WebCore namespace and use "using" on it
44 // as we do with things in WTF?
45
46 enum AdoptCOMTag { AdoptCOM };
47 enum QueryTag { Query };
48 enum CreateTag { Create };
49
50 template<typename T> class COMPtr {
51 public:
COMPtr()52 COMPtr() : m_ptr(0) { }
COMPtr(T * ptr)53 COMPtr(T* ptr) : m_ptr(ptr) { if (m_ptr) m_ptr->AddRef(); }
COMPtr(AdoptCOMTag,T * ptr)54 COMPtr(AdoptCOMTag, T* ptr) : m_ptr(ptr) { }
COMPtr(const COMPtr & o)55 COMPtr(const COMPtr& o) : m_ptr(o.m_ptr) { if (T* ptr = m_ptr) ptr->AddRef(); }
56
COMPtr(QueryTag,IUnknown * ptr)57 COMPtr(QueryTag, IUnknown* ptr) : m_ptr(copyQueryInterfaceRef(ptr)) { }
COMPtr(QueryTag,const COMPtr<U> & ptr)58 template<typename U> COMPtr(QueryTag, const COMPtr<U>& ptr) : m_ptr(copyQueryInterfaceRef(ptr.get())) { }
59
COMPtr(CreateTag,const IID & clsid)60 COMPtr(CreateTag, const IID& clsid) : m_ptr(createInstance(clsid)) { }
61
62 // Hash table deleted values, which are only constructed and never copied or destroyed.
COMPtr(WTF::HashTableDeletedValueType)63 COMPtr(WTF::HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) { }
isHashTableDeletedValue()64 bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); }
65
~COMPtr()66 ~COMPtr() { if (m_ptr) m_ptr->Release(); }
67
get()68 T* get() const { return m_ptr; }
69
70 void clear();
71 T* leakRef();
72
73 T& operator*() const { return *m_ptr; }
74 T* operator->() const { return m_ptr; }
75
76 T** operator&() { ASSERT(!m_ptr); return &m_ptr; }
77
78 bool operator!() const { return !m_ptr; }
79
80 // This conversion operator allows implicit conversion to bool but not to other integer types.
81 typedef T* (COMPtr::*UnspecifiedBoolType)() const;
UnspecifiedBoolType()82 operator UnspecifiedBoolType() const { return m_ptr ? &COMPtr::get : 0; }
83
84 COMPtr& operator=(const COMPtr&);
85 COMPtr& operator=(T*);
86 template<typename U> COMPtr& operator=(const COMPtr<U>&);
87
query(IUnknown * ptr)88 void query(IUnknown* ptr) { adoptRef(copyQueryInterfaceRef(ptr)); }
query(const COMPtr<U> & ptr)89 template<typename U> void query(const COMPtr<U>& ptr) { query(ptr.get()); }
90
create(const IID & clsid)91 void create(const IID& clsid) { adoptRef(createInstance(clsid)); }
92
93 template<typename U> HRESULT copyRefTo(U**);
94 void adoptRef(T*);
95
96 // FIXME: Remove releaseRef once we change all callers to call leakRef instead.
releaseRef()97 T* releaseRef() { return leakRef(); }
98
99 private:
100 static T* copyQueryInterfaceRef(IUnknown*);
101 static T* createInstance(const IID& clsid);
hashTableDeletedValue()102 static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); }
103
104 T* m_ptr;
105 };
106
clear()107 template<typename T> inline void COMPtr<T>::clear()
108 {
109 if (T* ptr = m_ptr) {
110 m_ptr = 0;
111 ptr->Release();
112 }
113 }
114
leakRef()115 template<typename T> inline T* COMPtr<T>::leakRef()
116 {
117 T* ptr = m_ptr;
118 m_ptr = 0;
119 return ptr;
120 }
121
createInstance(const IID & clsid)122 template<typename T> inline T* COMPtr<T>::createInstance(const IID& clsid)
123 {
124 T* result;
125 if (FAILED(CoCreateInstance(clsid, 0, CLSCTX_ALL, __uuidof(result), reinterpret_cast<void**>(&result))))
126 return 0;
127 return result;
128 }
129
copyQueryInterfaceRef(IUnknown * ptr)130 template<typename T> inline T* COMPtr<T>::copyQueryInterfaceRef(IUnknown* ptr)
131 {
132 if (!ptr)
133 return 0;
134 T* result;
135 if (FAILED(ptr->QueryInterface(&result)))
136 return 0;
137 return result;
138 }
139
copyRefTo(U ** ptr)140 template<typename T> template<typename U> inline HRESULT COMPtr<T>::copyRefTo(U** ptr)
141 {
142 if (!ptr)
143 return E_POINTER;
144 *ptr = m_ptr;
145 if (m_ptr)
146 m_ptr->AddRef();
147 return S_OK;
148 }
149
adoptRef(T * ptr)150 template<typename T> inline void COMPtr<T>::adoptRef(T *ptr)
151 {
152 if (m_ptr)
153 m_ptr->Release();
154 m_ptr = ptr;
155 }
156
157 template<typename T> inline COMPtr<T>& COMPtr<T>::operator=(const COMPtr<T>& o)
158 {
159 T* optr = o.get();
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> template<typename U> inline COMPtr<T>& COMPtr<T>::operator=(const COMPtr<U>& o)
170 {
171 T* optr = o.get();
172 if (optr)
173 optr->AddRef();
174 T* ptr = m_ptr;
175 m_ptr = optr;
176 if (ptr)
177 ptr->Release();
178 return *this;
179 }
180
181 template<typename T> inline COMPtr<T>& COMPtr<T>::operator=(T* optr)
182 {
183 if (optr)
184 optr->AddRef();
185 T* ptr = m_ptr;
186 m_ptr = optr;
187 if (ptr)
188 ptr->Release();
189 return *this;
190 }
191
192 template<typename T, typename U> inline bool operator==(const COMPtr<T>& a, const COMPtr<U>& b)
193 {
194 return a.get() == b.get();
195 }
196
197 template<typename T, typename U> inline bool operator==(const COMPtr<T>& a, U* b)
198 {
199 return a.get() == b;
200 }
201
202 template<typename T, typename U> inline bool operator==(T* a, const COMPtr<U>& b)
203 {
204 return a == b.get();
205 }
206
207 template<typename T, typename U> inline bool operator!=(const COMPtr<T>& a, const COMPtr<U>& b)
208 {
209 return a.get() != b.get();
210 }
211
212 template<typename T, typename U> inline bool operator!=(const COMPtr<T>& a, U* b)
213 {
214 return a.get() != b;
215 }
216
217 template<typename T, typename U> inline bool operator!=(T* a, const COMPtr<U>& b)
218 {
219 return a != b.get();
220 }
221
222 namespace WTF {
223
224 template<typename P> struct HashTraits<COMPtr<P> > : GenericHashTraits<COMPtr<P> > {
225 static const bool emptyValueIsZero = true;
226 static void constructDeletedValue(COMPtr<P>& slot) { new (&slot) COMPtr<P>(HashTableDeletedValue); }
227 static bool isDeletedValue(const COMPtr<P>& value) { return value.isHashTableDeletedValue(); }
228 };
229
230 template<typename P> struct PtrHash<COMPtr<P> > : PtrHash<P*> {
231 using PtrHash<P*>::hash;
232 static unsigned hash(const COMPtr<P>& key) { return hash(key.get()); }
233 using PtrHash<P*>::equal;
234 static bool equal(const COMPtr<P>& a, const COMPtr<P>& b) { return a == b; }
235 static bool equal(P* a, const COMPtr<P>& b) { return a == b; }
236 static bool equal(const COMPtr<P>& a, P* b) { return a == b; }
237 };
238
239 template<typename P> struct DefaultHash<COMPtr<P> > { typedef PtrHash<COMPtr<P> > Hash; };
240 }
241
242 #endif
243