1 /*
2 * Copyright (C) 2008 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 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 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 ResourcePtr_h
27 #define ResourcePtr_h
28
29 #include "core/fetch/Resource.h"
30
31 namespace blink {
32
33 class ResourcePtrBase {
34 public:
35 ~ResourcePtrBase();
36
get()37 Resource* get() const { return m_resource; }
38 bool operator!() const { return !m_resource; }
clear()39 void clear() { setResource(0); }
40
41 // This conversion operator allows implicit conversion to bool but not to other integer types.
42 typedef Resource* ResourcePtrBase::*UnspecifiedBoolType;
UnspecifiedBoolType()43 operator UnspecifiedBoolType() const { return m_resource ? &ResourcePtrBase::m_resource : 0; }
44
45 protected:
ResourcePtrBase()46 ResourcePtrBase() : m_resource(0) { }
47 ResourcePtrBase(Resource*);
48 ResourcePtrBase(const ResourcePtrBase&);
49
50 void setResource(Resource*);
51
52 private:
53 ResourcePtrBase& operator=(const ResourcePtrBase&) { return *this; }
54
55 friend class Resource;
56
57 Resource* m_resource;
58 };
59
ResourcePtrBase(Resource * res)60 inline ResourcePtrBase::ResourcePtrBase(Resource* res)
61 : m_resource(res)
62 {
63 if (m_resource)
64 m_resource->registerHandle(this);
65 }
66
~ResourcePtrBase()67 inline ResourcePtrBase::~ResourcePtrBase()
68 {
69 if (m_resource)
70 m_resource->unregisterHandle(this);
71 }
72
ResourcePtrBase(const ResourcePtrBase & o)73 inline ResourcePtrBase::ResourcePtrBase(const ResourcePtrBase& o)
74 : m_resource(o.m_resource)
75 {
76 if (m_resource)
77 m_resource->registerHandle(this);
78 }
79
80 template <class R> class ResourcePtr : public ResourcePtrBase {
81 public:
ResourcePtr()82 ResourcePtr() { }
ResourcePtr(R * res)83 ResourcePtr(R* res) : ResourcePtrBase(res) { }
ResourcePtr(const ResourcePtr<R> & o)84 ResourcePtr(const ResourcePtr<R>& o) : ResourcePtrBase(o) { }
ResourcePtr(const ResourcePtr<U> & o)85 template<typename U> ResourcePtr(const ResourcePtr<U>& o) : ResourcePtrBase(o.get()) { }
86
get()87 R* get() const { return reinterpret_cast<R*>(ResourcePtrBase::get()); }
88 R* operator->() const { return get(); }
89
90 ResourcePtr& operator=(R* res) { setResource(res); return *this; }
91 ResourcePtr& operator=(const ResourcePtr& o) { setResource(o.get()); return *this; }
92 template<typename U> ResourcePtr& operator=(const ResourcePtr<U>& o) { setResource(o.get()); return *this; }
93
94 bool operator==(const ResourcePtrBase& o) const { return get() == o.get(); }
95 bool operator!=(const ResourcePtrBase& o) const { return get() != o.get(); }
96 };
97
98 template <class R, class RR> bool operator==(const ResourcePtr<R>& h, const RR* res)
99 {
100 return h.get() == res;
101 }
102 template <class R, class RR> bool operator==(const RR* res, const ResourcePtr<R>& h)
103 {
104 return h.get() == res;
105 }
106 template <class R, class RR> bool operator!=(const ResourcePtr<R>& h, const RR* res)
107 {
108 return h.get() != res;
109 }
110 template <class R, class RR> bool operator!=(const RR* res, const ResourcePtr<R>& h)
111 {
112 return h.get() != res;
113 }
114 }
115
116 #endif
117