From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-2.8 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD shortcircuit=no autolearn=no autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id A0B311F406 for ; Mon, 8 Jan 2018 11:43:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756191AbeAHLn3 (ORCPT ); Mon, 8 Jan 2018 06:43:29 -0500 Received: from mail-wm0-f41.google.com ([74.125.82.41]:42857 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756014AbeAHLn2 (ORCPT ); Mon, 8 Jan 2018 06:43:28 -0500 Received: by mail-wm0-f41.google.com with SMTP id b141so13627924wme.1 for ; Mon, 08 Jan 2018 03:43:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:references:user-agent:in-reply-to:date :message-id:mime-version:content-transfer-encoding; bh=fvoVwI68ESCY36fq4lbOlSHNNJtbMbnPfalglFAXsT8=; b=lTU3Tf3d9zAhW5dsT7LDasGdsNHQlX54Nw909cjhNAw6A9VQRwGKLHl4mLISrZ7mUl ao5IG6nk0zLAU80Kn5nrCF6WetIjtScHnYzucwoepk2YilFnuoo4crNv/xhrgpcrUm6I bTsqKXUcUc9q13Uw74vX2Nkp99h5kSK8EfzAOTsJPfKSogdKa0DnbeZjrifHv7fuI6qs H86Fr/P5ABaUqtu2BJlPwGIGEkmJ3+x3x4w9ocLHBDszIgiQ449c57jFiPtVPfK7lUcc NSfANobASjA2rJcoCJqtqZ1pfIAnaZXeETvz1lTsuhvVR+28lRaqF9lCrIfx2EcG1fCm C5Jw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:references:user-agent :in-reply-to:date:message-id:mime-version:content-transfer-encoding; bh=fvoVwI68ESCY36fq4lbOlSHNNJtbMbnPfalglFAXsT8=; b=sT18IB3XyWAL5oPDVz7ePeXg23V6BOazg0ijQbdjwR+nbB9E/+dy07L9vdnUfdHBmR bGyPTZp9r5dVbMLdc4adlC6OJ/TVUH89JM8JWP87Ss6ecSjLOapySGp0HGGieiQ6FvGm T4YkXXqYf8fRYwQ6J+YdV2oi/quRlRfFPWeLO4mp4HMcJnMznNZsnB3j/kVsSqH27Rhm gbe0Pb5EuMEWXRPNu4w9/xNGysDE4Q6QVDJVWwffHtPr+/HfzcFEVipCkHcZ71g0ZwW5 sdb24Qk9HWwUyaZNtHm2mj9m3UeokqXIB4YSdWEWK3aVJBwRfSXS7EmRWWA5em6M07IT FImw== X-Gm-Message-State: AKGB3mIslrOQMMzihp2I5/o5K9M8Zfpg2EDEei5qdw/3hlRBtrYe+ALT n+ezy+ghA547rEbkb6J1AK5tN2Og X-Google-Smtp-Source: ACJfBouyIf4/AaQVqyxQ9ry5bE+Bx+8EEp5maPKNF2QC+oVaUn/CFRBSIvXmo2XEdlc1A3/cDUsa1A== X-Received: by 10.80.145.173 with SMTP id g42mr16229364eda.156.1515411807023; Mon, 08 Jan 2018 03:43:27 -0800 (PST) Received: from evledraar (proxy-gw-a.booking.com. [5.57.21.8]) by smtp.gmail.com with ESMTPSA id 4sm6474076edf.81.2018.01.08.03.43.25 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 08 Jan 2018 03:43:25 -0800 (PST) From: =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason To: Derrick Stolee Cc: git@vger.kernel.org, dstolee@microsoft.com, git@jeffhostetler.com, peff@peff.net, gitster@pobox.com, johannes.schindelin@gmx.de, jrnieder@gmail.com Subject: Re: [RFC PATCH 00/18] Multi-pack index (MIDX) References: <20180107181459.222909-1-dstolee@microsoft.com> <87k1wtb8a4.fsf@evledraar.gmail.com> User-agent: Debian GNU/Linux 9.3 (stretch); Emacs 25.1.1; mu4e 0.9.19 In-reply-to: Date: Mon, 08 Jan 2018 12:43:25 +0100 Message-ID: <87fu7gbmoy.fsf@evledraar.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Mon, Jan 08 2018, Derrick Stolee jotted: > On 1/7/2018 5:42 PM, Ævar Arnfjörð Bjarmason wrote: >> If something cares about both throughput and e.g. is saving the >> abbreviated SHA-1s isn't it better off picking some arbitrary size >> (e.g. --abbrev=20), after all the default abbreviation is going to show >> something as small as possible, which may soon become ambigous after the >> next commit. > > Unfortunately, with the way the abbreviation algorithms work, using > --abbrev=20 will have similar performance problems because you still > need to inspect all packfiles to ensure there isn't a collision in the > first 20 hex characters. I meant (but forgot to write) that this would be some new mode, e.g. --abbrev=20 --no-abbrev-check which would just perform a substr() of the 40 character SHA-1. It might be interesting to add that for reasons completely unrelated to your series. Thanks for answering the rest.