1/*
2 * Copyright (C) 2009 Google 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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef ScopedPersistent_h
32#define ScopedPersistent_h
33
34#include <v8.h>
35#include "wtf/Noncopyable.h"
36
37namespace WebCore {
38
39template<typename T>
40class ScopedPersistent {
41    WTF_MAKE_NONCOPYABLE(ScopedPersistent);
42public:
43    ScopedPersistent() { }
44
45    ScopedPersistent(v8::Isolate* isolate, v8::Handle<T> handle)
46        : m_handle(isolate, handle)
47    {
48    }
49
50    ~ScopedPersistent()
51    {
52        clear();
53    }
54
55    ALWAYS_INLINE v8::Local<T> newLocal(v8::Isolate* isolate) const
56    {
57        return v8::Local<T>::New(isolate, m_handle);
58    }
59
60    template<typename P>
61    void setWeak(P* parameters, void (*callback)(const v8::WeakCallbackData<T, P>&))
62    {
63        m_handle.SetWeak(parameters, callback);
64    }
65
66    bool isEmpty() const { return m_handle.IsEmpty(); }
67
68    void set(v8::Isolate* isolate, v8::Handle<T> handle)
69    {
70        m_handle.Reset(isolate, handle);
71    }
72
73    // Note: This is clear in the OwnPtr sense, not the v8::Handle sense.
74    void clear()
75    {
76        m_handle.Reset();
77    }
78
79    bool operator==(const ScopedPersistent<T>& other)
80    {
81        return m_handle == other.m_handle;
82    }
83
84private:
85    // FIXME: This function does an unsafe handle access. Remove it.
86    friend class V8AbstractEventListener;
87    friend class V8PerIsolateData;
88    ALWAYS_INLINE v8::Persistent<T>& getUnsafe()
89    {
90        return m_handle;
91    }
92
93    v8::Persistent<T> m_handle;
94};
95
96} // namespace WebCore
97
98#endif // ScopedPersistent_h
99