/*

 *  Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.

 *  Copyright (C) 2008 Collabora Ltd.

 *  Copyright (C) 2009 Martin Robinson

 *

 *  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 WTF_GRefPtr_h

#define WTF_GRefPtr_h

#include "AlwaysInline.h"

#include <algorithm>

typedef struct _GHashTable GHashTable;

typedef void* gpointer;

extern "C" void g_object_unref(gpointer object);

extern "C" gpointer  g_object_ref_sink(gpointer object);

namespace WTF {

enum GRefPtrAdoptType { GRefPtrAdopt };

template <typename T> inline T* refGPtr(T*);

template <typename T> inline void derefGPtr(T*);

template <typename T> class GRefPtr;

template <typename T> GRefPtr<T> adoptGRef(T*);

template <> GHashTable* refGPtr(GHashTable* ptr);

template <> void derefGPtr(GHashTable* ptr);

template <typename T> class GRefPtr {

public:

    GRefPtr() : m_ptr(0) { }

    GRefPtr(T* ptr) : m_ptr(ptr) { if (ptr) refGPtr(ptr); }

    GRefPtr(const GRefPtr& o) : m_ptr(o.m_ptr) { if (T* ptr = m_ptr) refGPtr(ptr); }

    template <typename U> GRefPtr(const GRefPtr<U>& o) : m_ptr(o.get()) { if (T* ptr = m_ptr) refGPtr(ptr); }

    ~GRefPtr() { if (T* ptr = m_ptr) derefGPtr(ptr); }

    void clear()

    {

        T* ptr = m_ptr;

        m_ptr = 0;

        if (ptr)

            derefGPtr(ptr);

    }

    T* get() const { return m_ptr; }

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

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

    bool operator!() const { return !m_ptr; }

    // This conversion operator allows implicit conversion to bool but not to other integer types.

    typedef T* GRefPtr::*UnspecifiedBoolType;

    operator UnspecifiedBoolType() const { return m_ptr ? &GRefPtr::m_ptr : 0; }

    GRefPtr& operator=(const GRefPtr&);

    GRefPtr& operator=(T*);

    template <typename U> GRefPtr& operator=(const GRefPtr<U>&);

    void swap(GRefPtr&);

    friend GRefPtr adoptGRef<T>(T*);

private:

    static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); }

    // Adopting constructor.

    GRefPtr(T* ptr, GRefPtrAdoptType) : m_ptr(ptr) {}

    T* m_ptr;

};

template <typename T> inline GRefPtr<T>& GRefPtr<T>::operator=(const GRefPtr<T>& o)

{

    T* optr = o.get();

    if (optr)

        refGPtr(optr);

    T* ptr = m_ptr;

    m_ptr = optr;

    if (ptr)

        derefGPtr(ptr);

    return *this;

}

template <typename T> inline GRefPtr<T>& GRefPtr<T>::operator=(T* optr)

{

    T* ptr = m_ptr;

    if (optr)

        refGPtr(optr);

    m_ptr = optr;

    if (ptr)

        derefGPtr(ptr);

    return *this;

}

template <class T> inline void GRefPtr<T>::swap(GRefPtr<T>& o)

{

    std::swap(m_ptr, o.m_ptr);

}

template <class T> inline void swap(GRefPtr<T>& a, GRefPtr<T>& b)

{

    a.swap(b);

}

template <typename T, typename U> inline bool operator==(const GRefPtr<T>& a, const GRefPtr<U>& b)

{

    return a.get() == b.get();

}

template <typename T, typename U> inline bool operator==(const GRefPtr<T>& a, U* b)

{

    return a.get() == b;

}

template <typename T, typename U> inline bool operator==(T* a, const GRefPtr<U>& b)

{

    return a == b.get();

}

template <typename T, typename U> inline bool operator!=(const GRefPtr<T>& a, const GRefPtr<U>& b)

{

    return a.get() != b.get();

}

template <typename T, typename U> inline bool operator!=(const GRefPtr<T>& a, U* b)

{

    return a.get() != b;

}

template <typename T, typename U> inline bool operator!=(T* a, const GRefPtr<U>& b)

{

    return a != b.get();

}

template <typename T, typename U> inline GRefPtr<T> static_pointer_cast(const GRefPtr<U>& p)

{

    return GRefPtr<T>(static_cast<T*>(p.get()));

}

template <typename T, typename U> inline GRefPtr<T> const_pointer_cast(const GRefPtr<U>& p)

{

    return GRefPtr<T>(const_cast<T*>(p.get()));

}

template <typename T> inline T* getPtr(const GRefPtr<T>& p)

{

    return p.get();

}

template <typename T> GRefPtr<T> adoptGRef(T* p)

{

    return GRefPtr<T>(p, GRefPtrAdopt);

}

template <typename T> inline T* refGPtr(T* ptr)

{

    if (ptr)

        g_object_ref_sink(ptr);

    return ptr;

}

template <typename T> inline void derefGPtr(T* ptr)

{

    if (ptr)

        g_object_unref(ptr);

}

} // namespace WTF

using WTF::GRefPtr;

using WTF::refGPtr;

using WTF::derefGPtr;

using WTF::adoptGRef;

using WTF::static_pointer_cast;

using WTF::const_pointer_cast;

#endif // WTF_GRefPtr_h