Re: [QUESTION] about .git/info/grafts file

From: Junio C Hamano <junkio@cox.net>
Date: Jan 20, 2006, 01:14 UTC
Message-ID: <7virsf7lb9.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <7v8xtdrqwg.fsf@assigned-by-dhcp.cox.net>

Junio C Hamano <junkio@cox.net> writes:

Show 6 quoted lines

> It _might_ work if you tell your downloader to have a proper
> graft file in his repository to cauterize the commit ancestry
> chain _before_ he pulls from you, though.  I haven't tried it
> (and honestly I did not feel that is something important to
> support, so it might work by accident but that is not by
> design).

I just tried it and it actually works.

	$ git clone git.git junk
        $ cd junk ;# I am not brave enough to risk the real thing ;-)
	$ git rev-parse master~4 >.git/refs/info/grafts
        $ cd ..
        $ mkdir cloned
        $ cd cloned
        $ git init-db
        $ cp ../junk/.git/info/grafts .git/info/
	$ git clone-pack ../baz
	$ git fsck-objects --full
	$ git log --pretty=short | cat

This "only the tip of the git.git" repository has about 450 objects in it, fully packed because of clone-pack, with one 680K packfile. I think the true full history of git.git/ packed into one is aruond a 5MB packfile. I suspect a bigger repository would not see that much size reduction, as Linus already explained here.

You could emulate what I just did above to prepare the equivalent of "baz" above, and make it available over git:// protocol, say at git://franck.example.com/franck.git/.

Then you tell your downloaders something like this:

	This repository has been cauterized, and cannot be
	cloned in a usual manner, but once you make a clone
	everything including further incremental updates should
	work.

        To clone this repository:

		$ mkdir franckproject ;# make a new repository
		$ cd franckproject && git init-db
		$ echo 'XXxxxxXXxxx' >.git/info/grafts
		$ git clone-pack git://franck.example.com/franck.git/