From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Subject: Re: RFC: New diff-delta.c implementation Date: Sat, 22 Apr 2006 15:58:46 -0400 (EDT) Message-ID: References: <602974A9-09A3-46E9-92D6-D30728923C11@adacore.com> <7v7j5hkglq.fsf@assigned-by-dhcp.cox.net> <7vslo5ikmk.fsf@assigned-by-dhcp.cox.net> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: Geert Bosch , Git Mailing List X-From: git-owner@vger.kernel.org Sat Apr 22 21:58:45 2006 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by ciao.gmane.org with esmtp (Exim 4.43) id 1FXOFf-00064H-N3 for gcvg-git@gmane.org; Sat, 22 Apr 2006 21:58:44 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751110AbWDVT6k (ORCPT ); Sat, 22 Apr 2006 15:58:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751109AbWDVT6k (ORCPT ); Sat, 22 Apr 2006 15:58:40 -0400 Received: from relais.videotron.ca ([24.201.245.36]:4606 "EHLO relais.videotron.ca") by vger.kernel.org with ESMTP id S1751110AbWDVT6k (ORCPT ); Sat, 22 Apr 2006 15:58:40 -0400 Received: from xanadu.home ([74.56.108.184]) by VL-MH-MR002.ip.videotron.ca (Sun Java System Messaging Server 6.2-2.05 (built Apr 28 2005)) with ESMTP id <0IY5001HS3HRF6E0@VL-MH-MR002.ip.videotron.ca> for git@vger.kernel.org; Sat, 22 Apr 2006 15:58:39 -0400 (EDT) In-reply-to: <7vslo5ikmk.fsf@assigned-by-dhcp.cox.net> X-X-Sender: nico@localhost.localdomain To: Junio C Hamano Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: On Sat, 22 Apr 2006, Junio C Hamano wrote: > Nicolas Pitre 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