All of lore.kernel.org
 help / color / mirror / Atom feed
From: Taylor Blau <me@ttaylorr.com>
To: Jacob Vosmaer <jacob@gitlab.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH 1/1] builtin/pack-objects.c: avoid iterating all refs
Date: Tue, 19 Jan 2021 18:08:31 -0500	[thread overview]
Message-ID: <YAdmb3EfNVHYavNk@nand.local> (raw)
In-Reply-To: <20210119143348.27535-2-jacob@gitlab.com>

On Tue, Jan 19, 2021 at 03:33:48PM +0100, Jacob Vosmaer wrote:
> In git-pack-objects, we iterate over all the tags if the --include-tag
> option is passed on the command line. For some reason this uses
> for_each_ref which is expensive if the repo has many refs. We should
> use a prefix iterator instead.

OK, makes sense to me.

> Signed-off-by: Jacob Vosmaer <jacob@gitlab.com>
> ---
>  builtin/pack-objects.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
> index 2a00358f34..2b32bc93bd 100644
> --- a/builtin/pack-objects.c
> +++ b/builtin/pack-objects.c
> @@ -3740,7 +3740,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
>  	}
>  	cleanup_preferred_base();
>  	if (include_tag && nr_result)
> -		for_each_ref(add_ref_tag, NULL);
> +		for_each_fullref_in("refs/tags/", add_ref_tag, NULL, 0);

Makes sense. I was curious why it wasn't this way from the beginning in
f0a24aa56e (git-pack-objects: Automatically pack annotated tags if
object was packed, 2008-03-03).

The patch doesn't say, but presumably it was because there wasn't any
speed-up to be had iterating only a subset of references back then if
they were packed (did packed refs even exist in 2008? unsure). In any
case, builtin/pack-objects.c:add_ref_tag() discards anything that
doesn't start with "refs/tags/", so I think your change is doing the
right thing here.

That said, you could shorten this to use 'for_each_tag_ref()' instead
(which compiles to the exact same thing).

It probably wouldn't be a bad time to drop the extra prefix check in
add_ref_tag().

Thanks,
Taylor

  reply	other threads:[~2021-01-19 23:10 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-19 14:33 [PATCH 0/1] builtin/pack-objects.c: avoid iterating all refs Jacob Vosmaer
2021-01-19 14:33 ` [PATCH 1/1] " Jacob Vosmaer
2021-01-19 23:08   ` Taylor Blau [this message]
2021-01-19 23:33     ` Jeff King
2021-01-19 23:54       ` Taylor Blau
2021-01-19 23:15   ` Jeff King
2021-01-20  8:50   ` Ævar Arnfjörð Bjarmason
2021-01-20 15:02     ` Taylor Blau
2021-01-20 16:32       ` Ævar Arnfjörð Bjarmason
2021-01-20 19:53     ` Jeff King
2021-01-21 10:26       ` Ævar Arnfjörð Bjarmason
2021-01-21 15:34         ` Jeff King
2021-01-19 23:26 ` [PATCH 0/1] " Jeff King

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YAdmb3EfNVHYavNk@nand.local \
    --to=me@ttaylorr.com \
    --cc=git@vger.kernel.org \
    --cc=jacob@gitlab.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.