server/src/framework/Utilities/CountedReference/Reference.h

97 lines
3.4 KiB
C++

/*
* Copyright (C) 2005-2008 MaNGOS <http://getmangos.com/>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef MANGOS_REFERENCE_H
#define MANGOS_REFERENCE_H
/**
* Referencer<T>
* Referencer is an object that holds a reference holder that hold a reference
* counted object. When an object's reference count drop to zero, it removes
* the object. This is a non intrusive mechanism and any object at any point
* in time can be referenced. When and object is reference counted, do not
* pass the object directly to other methods but rather, pass its
* reference around. Objects can be reference counted in both single threaded
* model and multi-threaded model
*/
#include <stdexcept>
#include "Platform/Define.h"
#include "Policies/ThreadingModel.h"
#include "ReferenceHolder.h"
template
<
typename T,
class THREADING_MODEL = MaNGOS::SingleThreaded<T>
>
class MANGOS_DLL_DECL Referencer
{
typedef typename THREADING_MODEL::Lock Lock;
typedef ReferenceHolder<T, THREADING_MODEL> ReferenceeHolder;
public:
/// Constructs a referencer.
Referencer(T *ref = NULL);
/// Copy constructor
Referencer(const Referencer &obj) : i_holder(NULL) { *this = obj; }
/// Destructor
~Referencer();
/// Referencee accessor
T* referencee(void) { return (i_holder == NULL ? NULL : i_holder->i_referencee); }
const T* referencee(void) const { return (i_holder == NULL ? NULL : i_holder->i_referencee); }
//T& referencee(void){ return _referencee(); }
//const T& referencee(void) const { return const_cast<Referencer *>(this)->_referencee(); }
operator T&(void) { return _referencee(); }
operator const T&(void) const { return *const_cast<Referencer *>(this)->_referencee(); }
/// cast operators
T* operator*() { return (i_holder == NULL ? NULL : i_holder->i_referencee); }
T const * operator*() const { return (i_holder == NULL ? NULL : i_holder->i_referencee); }
/// overload operators
T* operator->() { return (i_holder == NULL ? NULL : i_holder->i_referencee); }
const T * operator->() const { return (i_holder == NULL ? NULL : i_holder->i_referencee); }
/// operator =
Referencer& operator=(const Referencer &obj);
Referencer& operator=(T *);
/// returns true if i_referencee is null
bool isNull(void) const { return i_holder == NULL; }
private:
T& _referencee(void)
{
if( i_holder == NULL )
throw std::runtime_error("Invalid access to null pointer");
return *i_holder->i_referencee;
}
void deReference(ReferenceeHolder *);
void addReference(ReferenceeHolder *);
// private data
ReferenceeHolder *i_holder;
};
#endif