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

On Sat, Dec 9, 2023 at 10:23 PM Heikki Linnakangas <hlinnaka(at)iki(dot)fi> wrote:
> Ok, works for me.

I finished up making a few more improvements:

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.

2. FileReadV/FileWriteV patch:

* further simplification of the traditional ENOSPC 'guess'
* unconstify() changed to raw cast (pending [1])
* fixed the DO_DB()-wrapped debugging code

3. smgrreadv/smgrwritev patch:

* improved ENOSPC handling
* improve description of EOF and ENOSPC handling
* fixed the sizes reported in dtrace static probes
* fixed some words in the docs about that
* changed error messages to refer to "blocks %u..%u"

4. smgrprefetch-with-nblocks patch has no change, hasn't drawn any
comments hopefully because it is uncontroversial.

I'm planning to commit these fairly soon.

[1] https://www.postgresql.org/message-id/flat/CA%2BhUKGK3OXFjkOyZiw-DgL2bUqk9by1uGuCnViJX786W%2BfyDSw%40mail.gmail.com