From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: thin packs ending up fat Date: Thu, 12 Jan 2012 23:19:37 -0800 Message-ID: <7vmx9sysqe.fsf@alter.siamese.dyndns.org> References: <20120112221523.GA3663@sigill.intra.peff.net> <20120112223234.GA4949@sigill.intra.peff.net> <7vwr8wz8u9.fsf@alter.siamese.dyndns.org> <20120113015117.GA8245@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org, Nicolas Pitre To: Jeff King X-From: git-owner@vger.kernel.org Fri Jan 13 08:19:47 2012 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1RlbQP-0006zh-GF for gcvg-git-2@lo.gmane.org; Fri, 13 Jan 2012 08:19:45 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752481Ab2AMHTl (ORCPT ); Fri, 13 Jan 2012 02:19:41 -0500 Received: from b-pb-sasl-quonix.pobox.com ([208.72.237.35]:56410 "EHLO smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752436Ab2AMHTk (ORCPT ); Fri, 13 Jan 2012 02:19:40 -0500 Received: from smtp.pobox.com (unknown [127.0.0.1]) by b-sasl-quonix.pobox.com (Postfix) with ESMTP id ECF0776EC; Fri, 13 Jan 2012 02:19:38 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=KwWKBlcr6JxpBiLZEHcbtajs4lE=; b=kHxzwc 8EpHTbhhgHkjDj4z85s5pE9w9+h1sSomO/NPg0NiAmw13siKsadLzVhf6y6N3S8s pds1g0dY5gov8MhmsFx4pv4WHR0uaJFzkC/u3jUMEYdeUcaVwWVbQbMXeiihTkYB oBRdmoSrq7pfrVsr2RRg/ZP+vxWf7sjpbQFCA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=ugYph56HSjVJUvyulCjthYLv4HEvHB8z levcfLR0Bpt1bCC6Hlptugs+cQkSer8aAKjLgMjKV6tLStzqBQBYeP/XT/xy+anO d64Z3znXHHT0FDn5iiUOtgNyk/qQFrcbxadZakYgw10ecQbZFi9F2X7gqcDmcDpD NzwVtTWwnpQ= Received: from b-pb-sasl-quonix.pobox.com (unknown [127.0.0.1]) by b-sasl-quonix.pobox.com (Postfix) with ESMTP id E2D6776EB; Fri, 13 Jan 2012 02:19:38 -0500 (EST) Received: from pobox.com (unknown [76.102.170.102]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by b-sasl-quonix.pobox.com (Postfix) with ESMTPSA id 79C8976EA; Fri, 13 Jan 2012 02:19:38 -0500 (EST) In-Reply-To: <20120113015117.GA8245@sigill.intra.peff.net> (Jeff King's message of "Thu, 12 Jan 2012 20:51:17 -0500") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) X-Pobox-Relay-ID: F404572E-3DB6-11E1-AA42-9DB42E706CDE-77302942!b-pb-sasl-quonix.pobox.com Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Jeff King writes: > On Thu, Jan 12, 2012 at 05:31:42PM -0800, Junio C Hamano wrote: > >> From: Jeff King >> Subject: [PATCH] thin-pack: try harder to create delta against preferred base > > I just sat down to write a nicer commit message, and behold, it was done > for me. Thanks. Thank _you_ for a quick response and correction. I wanted to make sure I understood the root cause of the issue and the approach the patch takes to address it, instead of committing something that smelled correct. And the only way I know to do so is to write it down. Especiallly, before coming up with the description, I was wondering if this kind of symptom appears in non-thin cases, but after writing down the justification for this patch, it became clear that we wouldn't have to worry too much about that case. In a non-thin pack, we need to record one object at least in a delta family in inflated base form, so we may as well send that one near the tip that is already in that form for that, letting the existing "avoid futile delta" heuristics to kick in. Other objects in the same delta family will delta against it.