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

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 10, 2017, 22:43 UTC
Message-ID: <xmqqpoipis42.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <a1297b9426e7980f41e9e662fc0f30717c576c3e.1486739428.git.johannes.schindelin@gmx.de>

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

Show 16 quoted lines

> 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.