Re: [PATCH] make shallow repository deepening more network efficient

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Sep 26, 2009, 13:26 UTC
Message-ID: <alpine.DEB.1.00.0909261524490.4985@pacific.mpi-cbg.de>
In-Reply-To: <7vmy58r72b.fsf@alter.siamese.dyndns.org>

Hi,

On Sat, 5 Sep 2009, Junio C Hamano wrote:

Show 23 quoted lines

> Nicolas Pitre <nico@cam.org> writes:
> 
> > First of all, I can't find any reason why thin pack generation is 
> > explicitly disabled when dealing with a shallow repository.  The 
> > possible delta base objects are collected from the edge commits which 
> > are always obtained through history walking with the same shallow refs 
> > as the client, Therefore the client is always going to have those base 
> > objects available. So let's remove that restriction.
> >
> > Then we can make shallow repository deepening much more efficient by 
> > using the remote's unshallowed commits as edge commits to get preferred 
> > base objects for thin pack generation.  On git.git, this makes the data 
> > transfer for the deepening of a shallow repository from depth 1 to depth 2
> > around 134 KB instead of 3.68 MB.
> >
> > Signed-off-by: Nicolas Pitre <nico@cam.org>
> 
> Dscho, this is your code from around ed09aef (support fetching into a
> shallow repository, 2006-10-30) and f53514b (allow deepening of a shallow
> repository, 2006-10-30).  The latter disables thin pack transfer but the
> log does not attempt to justify the change.
> 
> Have any comments?

Unfortunately, I do not have any. I tried to remember, then I tried to find some documentation, but stopped when I found out that I developed the code on an iBook which died early Nov 2006.

So no, I do not remember why the change.

Sorry, Dscho