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

124 lines
3.6 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_HEAP_MEMORY_H
#define NL_HEAP_MEMORY_H
#include "types_nl.h"
#include <map>
namespace NLMISC
{
// ***************************************************************************
/**
* A Heap manager. Work with any kind of memory.
* This heap manager is not designed for speed (because it stills use standard heap allocation), but for
* use with special memory or special cases where malloc/new cannot be used.
* \author Lionel Berenguier
* \author Nevrax France
* \date 2001
*/
class CHeapMemory
{
public:
/// Constructor
CHeapMemory();
~CHeapMemory();
/// reset the entire container. NB: no free() is made on the heap.
void reset();
/** init the heap. this reset() the heap. heap ptr is stored in this class, but no CHeapMemory methods
* write or read into. They use standard heap instead (new / delete).
* \param heap the heap ptr. heap should be at least N-bytes aligned, where N is the alignment you need (see
* param align, 4 by default).
* \param align Any size given to allocate() will be rounded to match this alignement.
* Valid values are 4,8,16, or 32. 4 by default.
*/
void initHeap(void *heap, uint size, uint align=4);
/// return the size passed in setHeap().
uint getHeapSize() const {return _HeapSize;}
/// return the heap size allocated.
uint getHeapSizeUsed() const {return _HeapSizeUsed;}
/** allocate a block of size bytes. return NULL if not enough space or if size==0.
* NB: for alignements consideration, allocation are aligned to 4 bytes.
*/
void *allocate(uint size);
/// free a block allocated with alloate(). no-op if NULL. nlstop() if don't find this block.
void free(void *ptr);
// *********************
private:
// The map size -> EmptySpace.
typedef std::multimap<uint, uint8*> TEmptySpaceSizeMap;
typedef TEmptySpaceSizeMap::iterator ItEmptySpaceSizeMap;
struct CEmptySpace
{
// The adress of this empty space, in the heap
uint8 *Ptr;
// The size of this empty space.
uint Size;
// An iterator of his place in the TEmptySpaceMap.
ItEmptySpaceSizeMap SizeIt;
};
// The map ptr -> EmptySpace.
typedef std::map<uint8*, CEmptySpace> TEmptySpacePtrMap;
typedef TEmptySpacePtrMap::iterator ItEmptySpacePtrMap;
// The map ptr -> size: AllocatedSpace;
typedef std::map<uint8*, uint> TAllocatedSpaceMap;
typedef TAllocatedSpaceMap::iterator ItAllocatedSpaceMap;
private:
uint8 *_HeapPtr;
uint _HeapSize;
uint _HeapSizeUsed;
uint _Alignment;
/// The array of empty spaces.
TEmptySpacePtrMap _EmptySpaces;
/// for allocate method, the size -> empty space map.
TEmptySpaceSizeMap _EmptySpaceMap;
// The map of allocated blocks.
TAllocatedSpaceMap _AllocatedSpaceMap;
void removeEmptySpace(CEmptySpace &space);
void addEmptySpace(CEmptySpace &space);
};
} // NLMISC
#endif // NL_HEAP_MEMORY_H
/* End of heap_memory.h */