OpenSceneGraph/include/osg/Referenced
2001-01-10 16:32:10 +00:00

104 lines
2.6 KiB
Plaintext

#ifndef OSG_REFERENCED
#define OSG_REFERENCED 1
#include <osg/Export>
namespace osg {
/** Convience functor for unreferencing objects.*/
template<class T>
struct UnrefOp
{
void operator () (T* node) { node->unref(); }
};
/** Smart pointer for handling referenced counted objects.*/
template<class T>
class ref_ptr
{
public:
ref_ptr() :_ptr(0L) {}
ref_ptr(T* t):_ptr(t) { if (_ptr) _ptr->ref(); }
ref_ptr(const ref_ptr& rp):_ptr(rp._ptr) { if (_ptr) _ptr->ref(); }
~ref_ptr() { if (_ptr) _ptr->unref(); }
ref_ptr& operator = (const ref_ptr& rp)
{
if (_ptr==rp._ptr) return *this;
if (_ptr) _ptr->unref();
_ptr = rp._ptr;
if (_ptr) _ptr->ref();
return *this;
}
ref_ptr& operator = (T* ptr)
{
if (_ptr==ptr) return *this;
if (_ptr) _ptr->unref();
_ptr = ptr;
if (_ptr) _ptr->ref();
return *this;
}
bool operator == (const ref_ptr& rp) const
{
return (_ptr==rp._ptr);
}
bool operator == (const T* ptr) const
{
return (_ptr==ptr);
}
bool operator != (const ref_ptr& rp) const
{
return (_ptr!=rp._ptr);
}
bool operator != (const T* ptr) const
{
return (_ptr!=ptr);
}
T& operator*() const { return *_ptr; }
T* operator->() const { return _ptr; }
bool operator!() const { return _ptr==0L; }
bool valid() const { return _ptr!=0L; }
T* get() const { return _ptr; }
private:
T* _ptr;
};
/** Base class from providing referencing counted objects.*/
class Referenced
{
public:
Referenced() { _refCount=0; }
Referenced(Referenced&) { _refCount=0; }
Referenced& operator = (Referenced&) { return *this; }
/** increment the reference count by one, indicating that
this object has another pointer which is referencing it.*/
void ref() { ++_refCount; }
/** decrement the reference count by one, indicating that
a pointer to this object is referencing it. If the
refence count goes to zero, it is assumed that this object
is nolonger referenced and is automatically deleted.*/
void unref() { --_refCount; if (_refCount<=0) delete this; }
/** return the number pointers currently referencing this object. */
int referenceCount() { return _refCount; }
protected:
virtual ~Referenced() {};
int _refCount;
};
};
#endif