Donald C. Kirker wrote:
for (copied = 0; copied < size; copied += numBytesWrittenP) {
MemSet(tempData, 4096, 0);
There is no need at all to do a MemSet(). The FileRead() is
going to write over the stuff in the buffer anyway.
readBytes = FileRead( cache, tempData, 4096, 1, &fileError);
if (fileError != errNone) {
cacheError(fileError);
loopError = true;
break;
}
This looks OK, although I'd put 4096 as a constant instead of
putting it as a literal value in a zillion places.
err = VFSFileWrite(fileRefP, readBytes, tempData, &numBytesWrittenP);
if (err != errNone) {
VfsError(err);
loopError = true;
break;
}
}
This code isn't correct. VFSFileWrite() does not guarantee that it
will write everything in your buffer. Your buffer could have 512
bytes in it and VFSFileWrite() might write only 17 of them the first
time you call it.
So, you need a loop around VFSFileWrite(); something like this:
UInt32 bufferoffset = 0;
do
{
err = VFSFileWrite (fileRefP,
readBytes - bufferoffset, tempData + bufferoffset,
& numBytesWrittenP);
// error handling goes here
bufferoffset += numBytesWrittenP;
} while (bufferoffset < readBytes);
What that does is starts at the beginning of your buffer, then
writes as much of it as possible, advancing the offset by however
much was *actually* written, then keeps going as long as what's
in the buffer hasn't all been written yet.
- Logan
--
For information on using the PalmSource Developer Forums, or to unsubscribe,
please see http://www.palmos.com/dev/support/forums/
