mmioSetBuffer
The mmioSetBuffer
function enables or disables buffered I/O, or changes the buffer or buffer size
for a file opened by using the mmioOpen function.
MMRESULT mmioSetBuffer(
|
HMMIO hmmio, |
|
|
LPSTR pchBuffer, |
|
|
LONG cchBuffer, |
|
|
UINT wFlags |
|
|
); |
|
Parameters
hmmio
File handle
of the file.
pchBuffer
Address of an
application-defined buffer to use for buffered I/O. If this parameter is NULL, mmioSetBuffer
allocates an internal buffer for buffered I/O.
cchBuffer
Size, in
characters, of the application-defined buffer, or the size of the buffer for mmioSetBuffer
to allocate.
wFlags
Reserved;
must be zero.
Return Values
Returns zero
if successful or an error otherwise. If an error occurs, the file handle
remains valid. The following values are defined:
|
MMIOERR_CANNOTWRITE |
The
contents of the old buffer could not be written to disk, so the operation was
aborted. |
|
MMIOERR_OUTOFMEMORY |
The new
buffer could not be allocated, probably due to a lack of available memory. |
Remarks
To enable
buffering using an internal buffer, set pchBuffer to NULL and cchBuffer
to the desired buffer size.
To supply
your own buffer, set pchBuffer to point to the buffer, and set cchBuffer
to the size of the buffer.
To disable
buffered I/O, set pchBuffer to NULL and cchBuffer to zero.
If buffered
I/O is already enabled using an internal buffer, you can reallocate the buffer
to a different size by setting pchBuffer to NULL and cchBuffer to
the new buffer size. The contents of the buffer can be changed after resizing.
See Also