From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp2 ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms11 with LMTPS id kGofE8UK6V/GUgAA0tVLHw (envelope-from ) for ; Sun, 27 Dec 2020 22:29:25 +0000 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp2 with LMTPS id sDj5DsUK6V+KRwAAB5/wlQ (envelope-from ) for ; Sun, 27 Dec 2020 22:29:25 +0000 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id 0EF3A940149 for ; Sun, 27 Dec 2020 22:29:25 +0000 (UTC) Received: from localhost ([::1]:57140 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kteXT-0004st-Vc for larch@yhetil.org; Sun, 27 Dec 2020 17:29:23 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:35940) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kteXK-0004qk-9q for guix-devel@gnu.org; Sun, 27 Dec 2020 17:29:14 -0500 Received: from fencepost.gnu.org ([2001:470:142:3::e]:56919) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kteXK-0001Go-2i; Sun, 27 Dec 2020 17:29:14 -0500 Received: from [2a01:e0a:1d:7270:af76:b9b:ca24:c465] (port=53592 helo=ribbon) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1kteXI-0002lY-FT; Sun, 27 Dec 2020 17:29:13 -0500 From: =?utf-8?Q?Ludovic_Court=C3=A8s?= To: Miguel =?utf-8?Q?=C3=81ngel?= Arruga Vivas Subject: Re: Identical files across subsequent package revisions References: <87wnx9wlea.fsf@gnu.org> <878s9oy8f7.fsf@gmail.com> X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 7 =?utf-8?Q?Niv=C3=B4se?= an 229 de la =?utf-8?Q?R?= =?utf-8?Q?=C3=A9volution?= X-PGP-Key-ID: 0x090B11993D9AEBB5 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 3CE4 6455 8A84 FDC6 9DB4 0CFB 090B 1199 3D9A EBB5 X-OS: x86_64-pc-linux-gnu Date: Sun, 27 Dec 2020 23:29:11 +0100 In-Reply-To: <878s9oy8f7.fsf@gmail.com> ("Miguel =?utf-8?Q?=C3=81ngel?= Arruga Vivas"'s message of "Wed, 23 Dec 2020 14:10:52 +0100") Message-ID: <87y2hirih4.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: guix-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Guix Devel Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Migadu-Flow: FLOW_IN X-Migadu-Spam-Score: -2.82 Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=pass (policy=none) header.from=gnu.org; spf=pass (aspmx1.migadu.com: domain of guix-devel-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=guix-devel-bounces@gnu.org X-Migadu-Queue-Id: 0EF3A940149 X-Spam-Score: -2.82 X-Migadu-Scanner: scn0.migadu.com X-TUID: 8bys67eabcE0 Hi! Miguel =C3=81ngel Arruga Vivas skribis: > Another idea that might fit well into that kind of protocol---with > harder impact on the design, and probably with a high cost on the > runtime---would be the "upgrade" of the deduplication process towards a > content-based file system as git does[2]. This way the a description of > the nar contents (size, hash) could trigger the retrieval only of the > needed files not found in the current store. Yes, that=E2=80=99s what I had in mind. :-) It could go along these lines: 1. GET /digest/xyz-emacs; the digest contains a list of file/hash pairs essentially; 2. traverse digest and hardlink the files already in /gnu/store/.links to the target directory; 3. pipeline-GET the remaining files and install them. Like you write, since we already have deduplication, part of it comes for free. Ludo=E2=80=99.