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 SharedPersistent_h

    32 #define SharedPersistent_h

    33 

    34 #include <v8.h>

    35 #include <wtf/PassRefPtr.h>

    36 #include <wtf/RefCounted.h>

    37 

    38 namespace 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