/*

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

 *  Copyright (C) 2008 Collabora Ltd.

 *

 *  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 GOwnPtr_h

#define GOwnPtr_h

#include <algorithm>

#include <wtf/Assertions.h>

#include <wtf/Noncopyable.h>

// Forward delcarations at this point avoid the need to include GLib includes

// in WTF headers.

typedef struct _GError GError;

typedef struct _GList GList;

typedef struct _GCond GCond;

typedef struct _GMutex GMutex;

typedef struct _GPatternSpec GPatternSpec;

typedef struct _GDir GDir;

typedef struct _GHashTable GHashTable;

typedef struct _GFile GFile;

extern "C" void g_free(void*);

namespace WTF {

template <typename T> inline void freeOwnedGPtr(T* ptr);

template<> void freeOwnedGPtr<GError>(GError*);

template<> void freeOwnedGPtr<GList>(GList*);

template<> void freeOwnedGPtr<GCond>(GCond*);

template<> void freeOwnedGPtr<GMutex>(GMutex*);

template<> void freeOwnedGPtr<GPatternSpec>(GPatternSpec*);

template<> void freeOwnedGPtr<GDir>(GDir*);

template<> void freeOwnedGPtr<GHashTable>(GHashTable*);

template<> void freeOwnedGPtr<GFile>(GFile*);

template <typename T> class GOwnPtr : public Noncopyable {

public:

    explicit GOwnPtr(T* ptr = 0) : m_ptr(ptr) { }

    ~GOwnPtr() { freeOwnedGPtr(m_ptr); }

    T* get() const { return m_ptr; }

    T* release()

    {

        T* ptr = m_ptr;

        m_ptr = 0;

        return ptr;

    }

    T*& outPtr()

    {

        ASSERT(!m_ptr);

        return m_ptr;

    }

    void set(T* ptr)

    {

        ASSERT(!ptr || m_ptr != ptr);

        freeOwnedGPtr(m_ptr);

        m_ptr = ptr;

    }

    void clear()

    {

        T* ptr = m_ptr;

        m_ptr = 0;

        freeOwnedGPtr(ptr);

    }

    T& operator*() const

    {

        ASSERT(m_ptr);

        return *m_ptr;

    }

    T* operator->() const

    {

        ASSERT(m_ptr);

        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* GOwnPtr::*UnspecifiedBoolType;

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

    void swap(GOwnPtr& o) { std::swap(m_ptr, o.m_ptr); }

private:

    T* m_ptr;

};

template <typename T> inline void swap(GOwnPtr<T>& a, GOwnPtr<T>& b)

{

    a.swap(b);

}

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

{ 

    return a.get() == b; 

}

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

{

    return a == b.get(); 

}

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

{

    return a.get() != b; 

}

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

{ 

    return a != b.get(); 

}

template <typename T> inline typename GOwnPtr<T>::PtrType getPtr(const GOwnPtr<T>& p)

{

    return p.get();

}

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

{

    g_free(ptr);

}

} // namespace WTF

using WTF::GOwnPtr;

#endif // GOwnPtr_h