Re: [PATCH] preload-index: avoid lstat for skip-worktree items

[Junio C Hamano <gitster@pobox.com>]

Johannes Schindelin <johannes.schindelin@gmx.de> writes:

> Teach preload-index to avoid lstat() calls for index-entries
> with skip-worktree bit set.  This is a performance optimization.
> ...
> diff --git a/preload-index.c b/preload-index.c
> index c1fe3a3ef9c..70a4c808783 100644
> --- a/preload-index.c
> +++ b/preload-index.c
> @@ -53,6 +53,8 @@ static void *preload_thread(void *_data)
>  			continue;
>  		if (ce_uptodate(ce))
>  			continue;
> +		if (ce_skip_worktree(ce))
> +			continue;
>  		if (!ce_path_match(ce, &p->pathspec, NULL))
>  			continue;
>  		if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))

Because we are only interested in marking the ones that match
between the index and the working tree as "up-to-date", and we are
not doing the opposite (i.e. toggle "up-to-date" bit off by noticing
that things are now different) in this codepath, this change does
make sense.  The ones marked as "skip", even if there were an
unrelated file or directory at the path where the index expects a
regular file, can be safely ignored.

Thanks.