Re: RFC: New diff-delta.c implementation

From: Nicolas Pitre <nico@cam.org>
Date: Apr 22, 2006, 19:58 UTC
Message-ID: <Pine.LNX.4.64.0604221556170.2215@localhost.localdomain>
In-Reply-To: <7vslo5ikmk.fsf@assigned-by-dhcp.cox.net>

On Sat, 22 Apr 2006, Junio C Hamano wrote:

Show 17 quoted lines

> Nicolas Pitre <nico@cam.org> writes:
> 
> > Well, actually I was measuring a 10% speed improvement with a quick and 
> > naive (not memory efficient) approach for pack-objects with the current 
> > algorithm.
> >...
> > The idea to avoid memory pressure is to reverse the window processing 
> > such that the object to delta against is constant for the entire window 
> > instead of the current logic where the target object is constant.  This 
> > way there would be only one index in memory at all time.
> 
> Your are right.  The first led to the latter unexplored idea.
> 
> I expect to be offline most of the day today, and have other
> things I can work on for the next few days anyway, so if you or
> somebody else have an inclination and energy to reverse the
> delta window, I would appreciate that.

I'll probably give it a try.

I'm still reviewing Geert's code right now and found minor things pertaining to the GIT delta encoding here and there which probably explain why it doesn't pack the Linux kernel archive yet.

Nicolas