khanat-code-old/code/nel/include/nel/misc/pool_memory.h

130 lines
2.8 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_POOL_MEMORY_H
#define NL_POOL_MEMORY_H
#include "types_nl.h"
#include <list>
#include <vector>
namespace NLMISC
{
/**
* Pool memory allocation
*
* This memory manager allocates bloc of elements and free all the
* elements at the same time. Useful for temporary allocation.
*
* \author Cyril 'Hulud' Corvazier
* \author Nevrax France
* \date 2001
*/
template<class T>
class CPoolMemory
{
public:
/*
* Constructor
*
* \param blockSize is the default bloc size
*/
CPoolMemory (uint blockSize=10)
{
_BlockSize=blockSize;
_BlockPointer=_BlockList.end();
}
/*
* Allocate an element.
*
* Return a pointer on the element.
*/
T* allocate ()
{
// End of block ?
if ( (_BlockPointer!=_BlockList.end()) && (_BlockPointer->size()>=_BlockSize) )
{
// Get next block
_BlockPointer++;
}
// Out of memory ?
if (_BlockPointer==_BlockList.end())
{
// Add a block
_BlockList.resize (_BlockList.size()+1);
// Pointer on the new block
_BlockPointer=_BlockList.end ();
_BlockPointer--;
// Reserve it
_BlockPointer->reserve (_BlockSize);
}
// Allocate
_BlockPointer->resize (_BlockPointer->size()+1);
// Return the pointer
return &*((_BlockPointer->end ()-1));
}
/*
* Free all the elements allocated since last free(). Memory is kept for next allocations.
*/
void free ()
{
typename std::list< std::vector<T> >::iterator ite=_BlockList.begin();
while (ite!=_BlockList.end())
{
// Clear the block
ite->clear ();
// Check size in not zero
nlassert (ite->capacity ()>0);
ite++;
}
// Pointer at the beginning
_BlockPointer=_BlockList.begin();
}
/*
* Purge memory. All the memory used by the allocator is freid for real.
*/
void purge ()
{
_BlockList.clear();
_BlockPointer=_BlockList.end();
}
private:
uint _BlockSize;
std::list< std::vector<T> > _BlockList;
typename std::list< std::vector<T> >::iterator _BlockPointer;
};
} // NLMISC
#endif // NL_POOL_MEMORY_H
/* End of pool_memory.h */