From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, FROM_EXCESS_BASE64,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id C134A1F453 for ; Mon, 1 Oct 2018 15:17:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729539AbeJAVzi (ORCPT ); Mon, 1 Oct 2018 17:55:38 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:42317 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729480AbeJAVzi (ORCPT ); Mon, 1 Oct 2018 17:55:38 -0400 Received: by mail-wr1-f67.google.com with SMTP id b11-v6so14391862wru.9 for ; Mon, 01 Oct 2018 08:17:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=o5eT8btDnYzmm+hNAVbefD0718wYJ/SCA+YTtjyfsb0=; b=m5fqUGzaGMdBeqfA1npu7CtZdA5kzXcKvd1gg7PktzhdxsJptujOME8mtiUi+ABend fAPLl1QKtqP9PPFCjuHdz60MxqGQcKZL6GwQlBYwNgOd1RI3MS5yjGXpyLg05e+89wjF pu1Oh3PTtORysHFmuLUNymB5oPtYdRueD1JgDRB0Vl3ZSox0BXp0jze/Ur12oGSUfusR 0n/AmHlRNH9MeQi/uChULikL8MAEAQCj/BrMkkK1fmH/OMYZI+MmKSnwZGq0ALxAoodh ibV/96xhHTfzXIidZAA44hI9Gf+IQL1XU5fC9o3rRoeUwFrVDHOPT5qzeT9JSU0Q7ubi 4Ywg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=o5eT8btDnYzmm+hNAVbefD0718wYJ/SCA+YTtjyfsb0=; b=aqw2sAsi1+8mXas5BqCkzlbGTvQE6DG4w4umhDz9T/kIsDqYcJBev95hGZJthMQDXm xtUBKUGbhoqL6/9Ag+27FkN4iFGhclvBd1wlmP5YOwW2qHSzbcCLZhDJktfMOPHJFRdG jBvEUF2wzx9Lf9RyPtAW2zO2hY0oOW+sYWpgJvuJa2fdmFjmgVNMZAe3k0tTVo9fb5G+ AcknMz9m+FE6OIX6kUCZhBj0sMR5iYoRX8NmvQ+0n9i2Lnbo9wotup9v5vnGOb7nn0cK yMBYYyxhP8QdUdrn9FdrKhNMrIppSHwAStx5e42B1v3YYyLffj8YX1Sg18dmDiIj9Xdq R9Jg== X-Gm-Message-State: ABuFfohM2REBdA8z8f4gLf012wDGwFwLbrJdtSiSdLeM9l8zCAYxPk50 OavpWZ2vCJ2yQ/lCVh1MYvU= X-Google-Smtp-Source: ACcGV60HxK/eMdkO473wponGR/ZYZpMEjeGnpsnsz0oGs7SIXkBmmiy+xB9gS1cI/b0Wg70e9W3gdg== X-Received: by 2002:a5d:4706:: with SMTP id y6-v6mr7132125wrq.256.1538407039623; Mon, 01 Oct 2018 08:17:19 -0700 (PDT) Received: from localhost (x4db10555.dyn.telefonica.de. [77.177.5.85]) by smtp.gmail.com with ESMTPSA id b74-v6sm17058068wma.8.2018.10.01.08.17.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 01 Oct 2018 08:17:18 -0700 (PDT) Date: Mon, 1 Oct 2018 17:17:16 +0200 From: SZEDER =?utf-8?B?R8OhYm9y?= To: Ben Peart Cc: git@vger.kernel.org, gitster@pobox.com, pclouds@gmail.com, Ben Peart Subject: Re: [PATCH v7 3/7] eoie: add End of Index Entry (EOIE) extension Message-ID: <20181001151716.GL23446@localhost> References: <20180823154053.20212-1-benpeart@microsoft.com> <20181001134556.33232-1-peartben@gmail.com> <20181001134556.33232-4-peartben@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20181001134556.33232-4-peartben@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Mon, Oct 01, 2018 at 09:45:52AM -0400, Ben Peart wrote: > From: Ben Peart > > The End of Index Entry (EOIE) is used to locate the end of the variable > length index entries and the beginning of the extensions. Code can take > advantage of this to quickly locate the index extensions without having > to parse through all of the index entries. > > Because it must be able to be loaded before the variable length cache > entries and other index extensions, this extension must be written last. > The signature for this extension is { 'E', 'O', 'I', 'E' }. > > The extension consists of: > > - 32-bit offset to the end of the index entries > > - 160-bit SHA-1 over the extension types and their sizes (but not > their contents). E.g. if we have "TREE" extension that is N-bytes > long, "REUC" extension that is M-bytes long, followed by "EOIE", > then the hash would be: > > SHA-1("TREE" + + > "REUC" + ) > > Signed-off-by: Ben Peart I think the commit message should explicitly mention that this this extension - will always be written and why, - but is optional, so other Git implementations not supporting it will have no troubles reading the index, - and that it is written even to the shared index and why, and that because of this the index checksums in t1700 had to be updated.