From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: [PATCH] find_unique_abbrev(): honor caller-supplied "len" better Date: Fri, 11 Mar 2011 00:33:12 -0500 Message-ID: <20110311053312.GC16605@sigill.intra.peff.net> References: <20101028163854.GA15450@elte.hu> <7veiba9ev2.fsf@alter.siamese.dyndns.org> <7vhbba38mm.fsf_-_@alter.siamese.dyndns.org> <7vzkp21ocm.fsf@alter.siamese.dyndns.org> <7vmxl21lwr.fsf@alter.siamese.dyndns.org> <7vipvq1hpw.fsf@alter.siamese.dyndns.org> <20110311052235.GA16605@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Linus Torvalds , git@vger.kernel.org, Namhyung Kim To: Junio C Hamano X-From: git-owner@vger.kernel.org Fri Mar 11 06:33:20 2011 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 1PxuyV-0000sa-Ob for gcvg-git-2@lo.gmane.org; Fri, 11 Mar 2011 06:33:20 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751278Ab1CKFdO (ORCPT ); Fri, 11 Mar 2011 00:33:14 -0500 Received: from 99-108-226-0.lightspeed.iplsin.sbcglobal.net ([99.108.226.0]:58855 "EHLO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751023Ab1CKFdO (ORCPT ); Fri, 11 Mar 2011 00:33:14 -0500 Received: (qmail 2651 invoked by uid 107); 11 Mar 2011 05:33:45 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) (smtp-auth username relayok, mechanism cram-md5) by peff.net (qpsmtpd/0.84) with ESMTPA; Fri, 11 Mar 2011 00:33:45 -0500 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Fri, 11 Mar 2011 00:33:12 -0500 Content-Disposition: inline In-Reply-To: <20110311052235.GA16605@sigill.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Fri, Mar 11, 2011 at 12:22:35AM -0500, Jeff King wrote: > This is basically the birthday problem used in hash collision analysis. > Which means that if we decide on some acceptable probability of > collision, we can figure out the hash-length required to keep the > probability of collision below that acceptable level for a repository > with objects. Urgh, that was supposed to be "...for a repository with _n_ objects". But hopefully that became clear as you read on. -Peff