MemoryManagerMemMap.cpp

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/* ========================================================================
 * PROJECT: ARToolKitPlus
 * ========================================================================
 * This work is based on the original ARToolKit developed by
 *   Hirokazu Kato
 *   Mark Billinghurst
 *   HITLab, University of Washington, Seattle
 * http://www.hitl.washington.edu/artoolkit/
 *
 * Copyright of the derived and new portions of this work
 *     (C) 2006 Graz University of Technology
 *
 * This framework 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 framework 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 framework; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * For further information please contact 
 *   Dieter Schmalstieg
 *   <schmalstieg@icg.tu-graz.ac.at>
 *   Graz University of Technology, 
 *   Institut for Computer Graphics and Vision,
 *   Inffeldgasse 16a, 8010 Graz, Austria.
 * ========================================================================
 ** @author   Daniel Wagner
 *
 * $Id: MemoryManagerMemMap.cpp 162 2006-04-19 21:28:10Z grabner $
 * @file
 * ======================================================================== */


#include <ARToolKitPlus/MemoryManagerMemMap.h>
#include <assert.h>


#if defined(_MSC_VER) || defined(_WIN32_WCE)

namespace ARToolKitPlus
{


MemoryManagerMemMap::MemoryManagerMemMap()
{
        _didInit = false;

        lpvMem = NULL;
        hMapObject = NULL;

        fullSize = reservedSize = 0;
}


MemoryManagerMemMap::~MemoryManagerMemMap()
{
        deinit();
}


bool
MemoryManagerMemMap::init(size_t nNumInitialBytes, size_t nNumGrowBytes)
{
        if(_didInit)
                return false;

        fullSize = nNumInitialBytes;

        hMapObject = CreateFileMappingW(INVALID_HANDLE_VALUE,           // use paging file
                                                                        NULL,                                           // default security attributes
                                                                        PAGE_READWRITE,                         // read/write access
                                                                        0,                                                      // size: high 32-bits
                                                                        (DWORD)nNumInitialBytes,        // size: low 32-bits
                                                                        L"myMemMap");                           // name of map object
        if (hMapObject == NULL) 
                return false;
 
        lpvMem = MapViewOfFile(hMapObject,     // object to map view of
                                                   FILE_MAP_WRITE, // read/write access
                                                   0,              // high offset:  map from
                                                   0,              // low offset:   beginning
                                                   0);             // default: map entire file


        _didInit = lpvMem != NULL;
        return _didInit;
}


bool
MemoryManagerMemMap::deinit()
{
        if(!_didInit)
                return false;

        if(!lpvMem || !hMapObject)
                return false;

        // Unmap shared memory from the process's address space.
        UnmapViewOfFile(lpvMem); 
        lpvMem = NULL;
 
        // Close the process's handle to the file-mapping object.
        CloseHandle(hMapObject); 
        hMapObject = NULL;

        _didInit = false;
        return true;
}


bool
MemoryManagerMemMap::didInit()
{
        return _didInit;
}


void*
MemoryManagerMemMap::getMemory(size_t nNumBytes)
{
        // check if enough memory is left
        //
        if(reservedSize+nNumBytes > fullSize)
        {
                assert(false && "out of memory in MemoryManagerMemMap");
                return NULL;
        }

        void* newBlock = reinterpret_cast<unsigned char*>(lpvMem) + reservedSize;

        reservedSize += nNumBytes;
        return newBlock;
}


void
MemoryManagerMemMap::releaseMemory(void* nMemoryBlock)
{
        if(!_didInit)
                return;

        assert(false && "MemoryManagerMemMap can not release memory...");
}

}  // namespace ARToolKitPlus

#endif  // defined(_MSC_VER) || defined(_WIN32_WCE)