SharedPersistent.h revision cad810f21b803229eb11403f9209855525a25d57 
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
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7 *
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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.
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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,
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24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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29 */
30
31#ifndef SharedPersistent_h
32#define SharedPersistent_h
33
34#include <v8.h>
35#include <wtf/PassRefPtr.h>
36#include <wtf/RefCounted.h>
37
38namespace WebCore {
39
40    // A shareable reference to a v8 persistent handle.  Using a shared
41    // persistent any number of objects can share a reference to a v8
42    // object and when it should no longer be accessible the object's
43    // owner can clear it.
44    template <typename T>
45    class SharedPersistent : public RefCounted<SharedPersistent<T> > {
46    public:
47        void set(v8::Persistent<T> value)
48        {
49            m_value = value;
50        }
51        v8::Persistent<T> get()
52        {
53            return m_value;
54        }
55        void disposeHandle()
56        {
57            if (!m_value.IsEmpty()) {
58              m_value.Dispose();
59              m_value.Clear();
60            }
61        }
62        static PassRefPtr<SharedPersistent<T> > create(v8::Persistent<T> value)
63        {
64            return adoptRef(new SharedPersistent<T>(value));
65        }
66        static PassRefPtr<SharedPersistent<T> > create()
67        {
68            return create(v8::Persistent<T>());
69        }
70    private:
71        explicit SharedPersistent(v8::Persistent<T> value) : m_value(value) { }
72        v8::Persistent<T> m_value;
73    };
74
75} // namespace WebCore
76
77#endif // SharedPersistent_h
78