Re: Streaming I/O, vectored I/O (WIP)

On Mon, Dec 11, 2023 at 10:28 PM Heikki Linnakangas <hlinnaka@iki.fi> wrote:
> On 11/12/2023 11:12, Thomas Munro wrote:
> > 1.  I eventually figured out how to generalise
> > compute_remaining_iovec() (as I now call it) so that the existing
> > pg_pwritev_with_retry() in file_utils.c could also use it, so that's
> > now done in a patch of its own.
>
> In compute_remaining_iovec():
> > 'source' and 'destination' may point to the same array, in which
> > case it is adjusted in-place; otherwise 'destination' must have enough
> > space for 'iovcnt' elements.
> Is there any use case for not adjusting it in place?
> pg_pwritev_with_retry() takes a const iovec array, but maybe just remove
> the 'const' and document that it scribbles on it?

I guess I just wanted to preserve pg_pwritev_with_retry()'s existing
prototype, primarily because it matches standard pwritev()/writev().