🚀 go-pugleaf

Ray wrote:
> Hi All
>
> I wish to map a simple data file (ascii text file in essence) into
> memory in my application so that subsequent calls to that file use
> the data in memory instead of reopening the file. I presume that this
> will be faster for large files (although Windows file caching may
> mean that I am mistaken about this).
>
> Have had a look at CreateFileMapping() and MapViewofFile() in the API
> Help but I find them a little confusing especially as there are no
> examples that show the usage of the data in the way I want.
>
> Can anyone point me to a source of more information and or examples,
> or could anyone kindly give an example of what I am trying to achieve.

Here's an example of a class that wraps up all the code:
http://www.microsoft.com/msj/0498/hoodtextfigs.htm#fig4

--

Sam Mildener

"Ray" <raymondlewis@beeb.net> wrote in message
news:3ebd068b@newsgroups.borland.com...

> Have had a look at CreateFileMapping() and
> MapViewofFile() in the API Help

Those are the correct functions to use, yes.

> I find them a little confusing especially as there are
> no examples that show the usage of the data in the
> way I want.

Here you go:

    HANDLE hFile = CreateFile(...);
    if( hFile != INVALID_HANDLE_VALUE )
    {
        HANDLE hMapping = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0,
0, NULL);
        if( hMapping != NULL )
        {
            LPBYTE lpData = (LPBYTE) MapViewOfFile(hMapping, FILE_MAP_READ,
0, 0, 0);
            if( lpData != NULL )
            {
                // use lpData as needed, not to exceed the size of
                // the file.  You can use can use GetFileSize() if you
                // need to determine the size of the file ahead of time

                UnmapViewOfFile(lpData);
            }

            CloseHandle(hMapping);
        }

        CloseHandle(hFile);
    }


Gambit

Thanks Remy works a treat

Ray