From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Pearce Subject: [PATCH] Improved pack format documentation. Date: Mon, 29 May 2006 03:17:18 -0400 Message-ID: <20060529071718.GD6061@spearce.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org X-From: git-owner@vger.kernel.org Mon May 29 09:17:31 2006 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by ciao.gmane.org with esmtp (Exim 4.43) id 1Fkc0C-000357-Mb for gcvg-git@gmane.org; Mon, 29 May 2006 09:17:25 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750720AbWE2HRW (ORCPT ); Mon, 29 May 2006 03:17:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750728AbWE2HRW (ORCPT ); Mon, 29 May 2006 03:17:22 -0400 Received: from corvette.plexpod.net ([64.38.20.226]:47762 "EHLO corvette.plexpod.net") by vger.kernel.org with ESMTP id S1750720AbWE2HRV (ORCPT ); Mon, 29 May 2006 03:17:21 -0400 Received: from cpe-72-226-60-173.nycap.res.rr.com ([72.226.60.173] helo=asimov.home.spearce.org) by corvette.plexpod.net with esmtpa (Exim 4.52) id 1Fkc07-0005Xv-0n; Mon, 29 May 2006 03:17:19 -0400 Received: by asimov.home.spearce.org (Postfix, from userid 1000) id 6FAF120E445; Mon, 29 May 2006 03:17:18 -0400 (EDT) To: Junio Hamano Content-Disposition: inline User-Agent: Mutt/1.5.11 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - corvette.plexpod.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [47 12] X-AntiAbuse: Sender Address Domain - spearce.org X-Source: X-Source-Args: X-Source-Dir: Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: While trying to implement a pack reader in Java I was mislead by some facts listed in this documentation as well as found a few details to be missing about the pack header. Signed-off-by: Shawn O. Pearce --- Documentation/technical/pack-format.txt | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-) diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt index ed2decc..0e1ffb2 100644 --- a/Documentation/technical/pack-format.txt +++ b/Documentation/technical/pack-format.txt @@ -5,8 +5,13 @@ GIT pack format - The header appears at the beginning and consists of the following: - 4-byte signature - 4-byte version number (network byte order) + 4-byte signature: + The signature is: {'P', 'A', 'C', 'K'} + + 4-byte version number (network byte order): + GIT currently accepts version number 2 or 3 but + generates version 2 only. + 4-byte number of objects contained in the pack (network byte order) Observation: we cannot have more than 4G versions ;-) and @@ -41,7 +46,7 @@ GIT pack format 8-byte integers to go beyond 4G objects per pack, but it is not strictly necessary. - - The header is followed by sorted 28-byte entries, one entry + - The header is followed by sorted 24-byte entries, one entry per object in the pack. Each entry is: 4-byte network byte order integer, recording where the -- 1.3.3.g45d8