Re: [PATCH] Prevent megablobs from gunking up git packs

From: Nicolas Pitre <nico@cam.org>
Date: May 23, 2007, 01:58 UTC
Message-ID: <alpine.LFD.0.99.0705222154560.3366@xanadu.home>
In-Reply-To: <7v3b1o758u.fsf@assigned-by-dhcp.cox.net>

On Tue, 22 May 2007, Junio C Hamano wrote:

Show 19 quoted lines

> Jakub Narebski <jnareb@gmail.com> writes:
> 
> > No, I was thinking about separate _kept_ pack (so it would be not 
> > repacked unless -f option is given) containing _only_ the large blobs.
> > The only difference between this and your proposal is that megablobs
> > would be in their mergablobs pack, but not loose.
> 
> I am not sure about the "unless -f option is given" part, but a
> single .kept pack that contains only problematic blobs would be
> an interesting experiment.
> 
>  (0) prepare object names of problematic blobs, in huge.txt, one
>      object name per line;
> 
>  (1) prepare a single pack that has them:
> 
>      $ N=$(git-pack-object --depth=0 --window=0 pack <huge.txt)
>      $ echo 'Huge blobs -- do not repack' >pack-$N.keep
>      $ mv pack-$N.* .git/object/pack/.

If you're going to keep this pack, I think it might be worth attempting deltas between those blobs anyway. If they ever deltify you'll gain in disk space. And if they don't, well, you wasted the CPU cycles only once. Unless you know for sure they're unlikely to deltify well.

Nicolas