Re: [PATCH v1 2/3] pack-bitmap.c: add "break" statement in "open_pack_bitmap()"

[Taylor Blau <me@ttaylorr.com>]

On Thu, Mar 24, 2022 at 11:40:02AM -0700, Junio C Hamano wrote:
> Teng Long <dyroneteng@gmail.com> writes:
>
> > There will be only one operant ".bitmap" file in repo, so let's
> > add "break" statement in "open_pack_bitmap()" when looping all
> > the packs in repo.
>
> Googling "operant" only gives a psychology term X-<.
>
>     : behavior (such as bar pressing by a rat to obtain food) that
>     operates on the environment to produce rewarding and reinforcing
>     effects.

I suspect that the author meant "operating", which I would probably have
written as "Git will only use information from a single .bitmap file in
the repository" or similar.

But...

> I do not quite get this.  We expect that there may be more than one
> .pack in the object store, and that is why we iterate over the packs
> get_all_packs() gives us.  Then for each of these packs, we try to
> open pack bitmap.
>
> Ah, are you referring to the current limitation that we can have
> only one .bitmap file, even when there are many packs in the object
> store?
>
> I wonder if that limitation is something we need to hardcode here.

...you're exactly right: if we see more than one pack bitmap in the
repository, we can and should warn there, since we'll only ever *use*
information from a single bitmap at a time.

That's the behavior before this patch which is guaranteed by t5310.74.
This patch causes that test to break, and I would suggest that is
telling us to drop this part of the series.

Thanks,
Taylor