Re: [PATCH v2 1/2] dir: consider worktree config in path recursion

[Elijah Newren <newren@gmail.com>]

On Tue, May 24, 2022 at 12:45 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> Elijah Newren <newren@gmail.com> writes:
>
> > On Wed, May 11, 2022 at 9:37 AM Junio C Hamano <gitster@pobox.com> wrote:
> >>
> >> Goss Geppert <gg.oss.dev@gmail.com> writes:
> >>
> >> > diff --git a/dir.c b/dir.c
> >> > index f2b0f24210..a1886e61a3 100644
> >> > --- a/dir.c
> >> > +++ b/dir.c
> >> > @@ -1893,9 +1893,31 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
> >>
> > [...]
> >>
> >> > +                     real_gitdir = real_pathdup(the_repository->gitdir, 0);
> >>
> >> This function is repeatedly called during the traversal.
> >>
> >> How expensive is it to keep calling real_pathdup() on the constant
> >> the_repository->gitdir just in case it might be the same as our true
> >> GIT_DIR?
> >
> > I agree that treat_directory is called many times, but this
> > real_pathdup() call is inside the "if (nested_repo)" block, so this
> > new real_pathdup() invocation should occur very seldom.  Or are you
> > worried about cases where users have *very* large numbers of bare
> > repositories nested under the working directory?
>
> No.  I wasn't worried about anything in particular.  I just wanted
> to get the feel of how deep a thought the patch was backed by by
> spot checking what was and what was not taken into account when
> designing the change.
>
> I do not care too much when there are very large numbers of things
> that cause this codepath to be exercised.  Strange situations can be
> left for later optimization only when they turn up in the real world
> and prove to be a problem.

Ah, gotcha.

> By the way, where is a bare repository involved?  did you mean
> non-bare aka worktree-full repository?

Yes, sorry, I meant non-bare repository.