/*

 * This file is part of the DOM implementation for KDE.

 *

 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)

 *           (C) 2000 Antti Koivisto (koivisto@kde.org)

 *           (C) 2000 Dirk Mueller (mueller@kde.org)

 * Copyright (C) 2003, 2005 Apple Computer, Inc.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public License

 * along with this library; see the file COPYING.LIB.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 *

 */

#ifndef DataRef_h

#define DataRef_h

namespace WebCore {

template <typename T> class DataRef {

public:

    DataRef()

        : m_data(0)

    {

    }

    DataRef(const DataRef<T>& d)

    {

        ASSERT(d.m_data);

        m_data = d.m_data;

        m_data->ref();

    }

    ~DataRef()

    {

        if (m_data)

            m_data->deref();

    }

    const T* get() const { return m_data; }

    T& operator*() const { return *m_data; }

    const T* operator->() const { return m_data; }

    T* access()

    {

        if (!m_data->hasOneRef()) {

            m_data->deref();

            m_data = new T(*m_data);

            m_data->ref();

        }

        return m_data;

    }

    void init()

    {

        ASSERT(!m_data);

        m_data = new T;

        m_data->ref();

    }

    DataRef<T>& operator=(const DataRef<T>& d)

    {

        ASSERT(d.m_data);

        d.m_data->ref();

        if (m_data)

            m_data->deref();

        m_data = d.m_data;

        return *this;

    }

    bool operator==(const DataRef<T>& o) const

    {

        ASSERT(m_data);

        ASSERT(o.m_data);

        return m_data == o.m_data || *m_data == *o.m_data;

    }

    bool operator!=(const DataRef<T>& o) const

    {

        ASSERT(m_data);

        ASSERT(o.m_data);

        return m_data != o.m_data && *m_data != *o.m_data;

    }

private:

    T* m_data;

};

} // namespace WebCore

#endif // DataRef_h