Re: [PATCH] Use OBJECT_INFO_QUICK to speedup git fetch-pack

From: Jeff King <peff@peff.net>
Date: Nov 27, 2017, 05:04 UTC
Message-ID: <20171127050420.GB6858@sigill>
In-Reply-To: <xmqqk1yce301.fsf@gitster.mtv.corp.google.com>

On Mon, Nov 27, 2017 at 01:53:34PM +0900, Junio C Hamano wrote:

Show 12 quoted lines

> > I'd be curious if the 5th patch there provides an additional speedup for
> > Takuto's case.
> 
> Indeed, it is a very good point.
> 
> IIUC, the 5th one is about fetching tons of refs that you have never
> seen, right?  If a repository that has trouble with everything-local
> is suffering because it right now has 300k remote-tracking branches,
> I'd imagine that these remote-tracking branches are being added at a
> considerable rate, so I'd not be surprised if these "new" refs
> benefits from that patch.  And it would be nice to know how much a
> real life scenario actually does improve.

Right, I think it will only kick in for new refs (and maybe deleted ones, but I didn't check).

I actually did have a real life scenario that was improved, but it's not very typical. As I've mentioned before, we keep a big shared-object repository for forks of a single repo, so a fairly common operation is

  git -C network.git fetch ../$fork.git +refs/*:refs/remotes/$fork/*

The first time that's run on a fork, everything looks like a new ref.

So "real life", but thankfully not life for most git users. :)

-Peff