khanat-opennel-code/code/nel/include/nel/misc/stl_block_allocator.h

250 lines
6.3 KiB
C++

// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010 Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#ifndef NL_STL_BLOCK_ALLOCATOR_H
#define NL_STL_BLOCK_ALLOCATOR_H
#include "types_nl.h"
#include "block_memory.h"
namespace NLMISC {
// ***************************************************************************
/**
* This class is a STL block allocator which use CBlockMemory. see CBlockMemory for description
* of block memory management/advantages.
*
* This class works with STLPort. It implements __stl_alloc_rebind() (not C++ standard??) to work properly
* with list<>/set<> etc... node allocations.
*
* NB: if used with a vector<> or a deque<> (ie if allocate(..,n) is called with n>1), it's still work,
* but it's use malloc()/free() instead, so it is fully useless in this case :)
*
* CSTLBlockAllocator use a pointer on a CBlockMemory, so multiple containers can share the same
* blockMemory, for maximum space/speed efficiency.
*
* Because of CBlockMemory allocation scheme, only same containers of same types can share the
* same CBlockMemory instance (eg: "list<uint, &myBlockMemory>; vector<uint, &myBlockMemory>;" is invalid and
* will assert when allocations will occur).
*
* To construct a container which use this allocator, do like this:
* list<uint, CSTLBlockAllocator<uint>> myList( ptrOnBlockMemory );
*
* But see CSTLBlockList for easier list instanciation, because using it, you'll do like this:
* CSTLBlockList<uint> myList(ptrOnBlockMemory);
*
* Note: CSTLBlockAllocator take only 4 bytes in memory (a ptr on a CBlockMemory)
*
* \author Lionel Berenguier
* \author Nevrax France
* \date 2001
*/
template<class T>
class CSTLBlockAllocator : public std::allocator< T >
{
public:
/// Constructor. Must gives a blockMemory to ctor. NB: must gives a CBlockMemory<T, false> !!!
CSTLBlockAllocator(CBlockMemory<T, false> *bm)
{
}
/// copy ctor
CSTLBlockAllocator(const CSTLBlockAllocator<T> &other) : std::allocator<T>(other)
{
}
/// dtor
~CSTLBlockAllocator()
{
}
};
#if 0
#if defined(NL_OS_WINDOWS) && !defined(_STLP_MEMBER_TEMPLATE_CLASSES)
template<class T>
class CSTLBlockAllocator
{
public:
/// \name standard allocator interface.
// @{
typedef T value_type;
typedef value_type *pointer;
typedef const T* const_pointer;
typedef T& reference;
typedef const T& const_reference;
typedef size_t size_type;
typedef ptrdiff_t difference_type;
pointer adress(reference x) const
{
return &x;
}
const_pointer adress(const_reference x) const
{
return &x;
}
void construct(pointer p, const T &val)
{
new (p) T(val);
}
void destroy(pointer p)
{
p->T::~T();
}
// @}
public:
/// Constructor. Must gives a blockMemory to ctor. NB: must gives a CBlockMemory<T, false> !!!
CSTLBlockAllocator(CBlockMemory<T, false> *bm) : _BlockMemory(bm)
{
}
/// copy ctor
CSTLBlockAllocator(const CSTLBlockAllocator<T> &other) : _BlockMemory(other._BlockMemory)
{
// just copy the block memory from the other allocator.
}
/// dtor
~CSTLBlockAllocator()
{
_BlockMemory= NULL;
}
pointer allocate(size_type n, const_pointer hint= NULL)
{
if(n==0)
return NULL;
// If sizeof 1, use CBlockMemory allocation
if(n==1)
{
#ifdef NL_DEBUG
// verify that we allocate with good size!! (verify __stl_alloc_rebind scheme).
// ie an allocator can be used only to allocate a kind of element
uint eltSize= std::max(sizeof(T), sizeof(void*));
nlassert( eltSize == _BlockMemory->__stl_alloc_getEltSize() );
#endif
// and allocate.
return _BlockMemory->allocate();
}
// else use std malloc
else
return (T*)new uint8[n*sizeof(T)];
}
void deallocate(void *p, size_type n)
{
if(n==0)
return;
// If sizeof 1, use CBlockMemory allocation
if(n==1)
_BlockMemory->free((T*)p);
// else use std free
else
delete [] ((uint8*)p);
}
template <class _Tp, class U>
CSTLBlockAllocator<U>& __stl_alloc_rebind(CSTLBlockAllocator<_Tp>& __a, const U*)
{
// must change the internal eltSize of __a.
__a._BlockMemory->__stl_alloc_changeEltSize(sizeof(U));
// and just typecast/return him
return (CSTLBlockAllocator<U>&)(__a);
}
template <class _Tp, class U>
CSTLBlockAllocator<U> __stl_alloc_create(const CSTLBlockAllocator<_Tp>&, const U*)
{
return CSTLBlockAllocator<U>();
}
// *******************
private:
// The blockMemory used to allocate elements
CBlockMemory<T, false> *_BlockMemory;
};
#else // NL_OS_WINDOWS
# if !defined (__STL_USE_SGI_ALLOCATORS)
template<class T>
class CSTLBlockAllocator : public std::allocator< T >
{
public:
/// Constructor. Must gives a blockMemory to ctor. NB: must gives a CBlockMemory<T, false> !!!
CSTLBlockAllocator(CBlockMemory<T, false> *bm)
{
}
/// copy ctor
CSTLBlockAllocator(const CSTLBlockAllocator<T> &other) : std::allocator<T>(other)
{
}
/// dtor
~CSTLBlockAllocator()
{
}
};
# else // !defined (__STL_USE_SGI_ALLOCATORS)
class CSTLBlockAllocator : public __sgi_alloc
{
public:
/// Constructor. Must gives a blockMemory to ctor. NB: must gives a CBlockMemory<T, false> !!!
CSTLBlockAllocator(CBlockMemory<T, false> *bm)
{
}
/// copy ctor
CSTLBlockAllocator(const CSTLBlockAllocator<T> &other) : __sgi_alloc(other)
{
}
/// dtor
~CSTLBlockAllocator()
{
}
};
# endif // !defined (__STL_USE_SGI_ALLOCATORS)
#endif // NL_OS_WINDOWS
#endif // 0
} // NLMISC
#endif // NL_STL_BLOCK_ALLOCATOR_H
/* End of stl_block_allocator.h */