From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Shawn O. Pearce" Subject: Re: [PATCH] Documentation/git-bundle.txt: Dumping contents of any bundle Date: Thu, 1 Jan 2009 23:15:19 -0800 Message-ID: <20090102071519.GA14472@spearce.org> References: <20090101234815.GA9049@coredump.intra.peff.net> <878wputvnt.fsf@jidanni.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: peff@peff.net, johannes.schindelin@gmx.de, nico@cam.org, gitster@pobox.com, mdl123@verizon.net, git@vger.kernel.org To: jidanni@jidanni.org X-From: git-owner@vger.kernel.org Fri Jan 02 08:16:46 2009 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1LIeGy-0008Ff-Of for gcvg-git-2@gmane.org; Fri, 02 Jan 2009 08:16:45 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756757AbZABHPX (ORCPT ); Fri, 2 Jan 2009 02:15:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756642AbZABHPW (ORCPT ); Fri, 2 Jan 2009 02:15:22 -0500 Received: from george.spearce.org ([209.20.77.23]:33713 "EHLO george.spearce.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756291AbZABHPV (ORCPT ); Fri, 2 Jan 2009 02:15:21 -0500 Received: by george.spearce.org (Postfix, from userid 1001) id 8AECF38200; Fri, 2 Jan 2009 07:15:19 +0000 (UTC) Content-Disposition: inline In-Reply-To: <878wputvnt.fsf@jidanni.org> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: jidanni@jidanni.org wrote: > JK> diff --git a/builtin-unpack-objects.c b/builtin-unpack-objects.c > OK, I wish you luck in the fruition of the new --dump-delta option, and > can proofread the man pages involved, otherwise this is no area for > junior programmer me. This is rather insane. There's very little data inside of a delta. That's sort of the point of that level of compression, it takes up very little disk space and yet describes the change made. Almost nobody is going to want the delta without the base object it applies onto. No user of git is going to need that. I'd rather not carry dead code around in the tree for something nobody will ever use. FWIW, most Git deltas are "copy" instructions, they list a position and count in the base to copy data *from*. These take up less space then "insert" instructions, where new text is placed into the file. As the delta generator favors a smaller delta, it tends to create deltas that use the "copy" instruction more often than the "insert" instruction. So there is *very* little data in the delta, just ranges to copy from somewhere else. Without that other place (the delta base) all you can do is guess about those bits. Which you can do just as well with a few flips of a fair coin. :-) -- Shawn.