MemStrm.cpp

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//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// Project: uLib - User mode library.
// Module: Simplified global memory streams (when you need an IStream)
// Author: Copyright (c) Love Nystrom
// License: NNOSL (BSD descendant, see NNOSL.txt in the base directory).
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#include <uLib\MemStrm.h>

int _omsCount = 0; // OleInitialize sentry

// OpenMemStream -- Return an IStream in global memory

LPSTREAM OpenMemStream( size_t Size )
{
    LPSTREAM pStream; 
    HGLOBAL  hMem;
    HRESULT rc = (0 == _omsCount++) ? OleInitialize( NULL ) : S_OK;
    if (rc == S_OK || rc == S_FALSE) 
    {
        hMem = GlobalAlloc( GHND| GMEM_NODISCARD| GMEM_SHARE, Size );
        if (hMem) 
        {
            if (CreateStreamOnHGlobal( hMem, TRUE, &pStream ) == S_OK) 
                return pStream;
            else GlobalFree( hMem );
        }
    }
    return NULL;
}

// GetMemStreamHandle -- Return the current memory handle for the MemStream

HGLOBAL GetMemStreamHandle( LPSTREAM pStream ) 
{
    HGLOBAL handle = NULL;
    GetHGlobalFromStream( pStream, &handle );
    return handle;
}

// CloseMemStream -- Close the global memory IStream

void CloseMemStream( LPSTREAM pStream ) 
{
    pStream->Release();
    if (0 == --_omsCount) OleUninitialize();
}

// EOF