From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: sqlite3 Date: Tue, 28 Dec 2021 15:04:12 +0200 Message-ID: <83wnjolw37.fsf@gnu.org> References: <87tufmjyai.fsf@gnus.org> <871r28vg4y.fsf@gnus.org> <834k748wez.fsf@gnu.org> <831r288vne.fsf@gnu.org> <83zgow7fpi.fsf@gnu.org> <83y24g7dui.fsf@gnu.org> <8735mnr5cb.fsf@gnus.org> <83bl19zwwy.fsf@gnu.org> <87bl18g7r3.fsf@gnus.org> <83ee64ych1.fsf@gnu.org> <83o853pydo.fsf@gnu.org> <875yrbzjc5.fsf@gnus.org> <8335mfpox7.fsf@gnu.org> <83pmpjo79j.fsf@gnu.org> <83ilvbo2ab.fsf@gnu.org> <83h7avo1l6.fsf@gnu.org> <87o852cl7z.fsf@gnus.org> <83r19ym6vv.fsf@gnu.org> <87k0fqaxy8.fsf@gnus.org> <83o852m661.fsf@gnu.org> <83lf06m1ll.fsf@gnu.org> <87v8z99p1s.fsf@gnus.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="35516"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Lars Ingebrigtsen Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Dec 28 14:05:17 2021 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n2CAF-00090A-UP for ged-emacs-devel@m.gmane-mx.org; Tue, 28 Dec 2021 14:05:16 +0100 Original-Received: from localhost ([::1]:54742 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n2CAE-00053j-4X for ged-emacs-devel@m.gmane-mx.org; Tue, 28 Dec 2021 08:05:14 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:60222) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n2C9F-0004Is-GJ for emacs-devel@gnu.org; Tue, 28 Dec 2021 08:04:13 -0500 Original-Received: from [2001:470:142:3::e] (port=35618 helo=fencepost.gnu.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n2C9F-0005vW-1e; Tue, 28 Dec 2021 08:04:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=fziBZdOpIWPC4hL0c8mQotnkxIopZ7ySZ2NlqJ7/H+8=; b=dPAXhgaHOJaB 6oXhvkOG2iu0vl1UQtE3nlFRv1Jtz6WJ/vgCFvA5/1OqVJZs4wn/+0IrfmZZouOxxxJatpNr5jY/a 2VXM0V99Fs3lKdf+9/38lSFeVE0mhkNrv/+bN6Lsk2l0hh9F8peYFdF72cA9Ex822A0TsQxkCoEBo En4XMiG5D+24nF/nOeEhgnI4eE9/SAUXrJKEXOdblbpM+RZjV/pefFWcWZ+ZYM7LMCguztyaTViQ1 Y0YX8m9GJRqGUE+pj+UE+hCCnNNvR53fR3fId5MFmhAMCjRYqmsOga1Y13mfh3l6rAptZAqSqK6Hx 5AMN6aEyUkGtQx1Tyvw8yg==; Original-Received: from [87.69.77.57] (port=4999 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n2C9F-0003UM-0v; Tue, 28 Dec 2021 08:04:13 -0500 In-Reply-To: <87v8z99p1s.fsf@gnus.org> (message from Lars Ingebrigtsen on Tue, 28 Dec 2021 08:17:03 +0100) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:283505 Archived-At: > From: Lars Ingebrigtsen > Cc: emacs-devel@gnu.org > Date: Tue, 28 Dec 2021 08:17:03 +0100 > > Eli Zaretskii writes: > > > Hmmm... but our w32 'stat' emulation only supports time_t times, > > i.e. 1-second resolution. Could that be the reason for the problem? > > Yes, that would explain what we're seeing. Is there any chance the w32 > stat emulation could be fixed to support sub-second resolutions like it > does on other systems? It could, but it's not a trivial job, and doing it just for this use case could be overkill. Besides, Emacs does work with 'stat' which doesn't provide sub-second resolution, so this is not a w32 specific problem, at least in theory. > If not, I think we'll have to change how the values are stored, and add > a "header" section in the files themselves, so you'd have I think this is a good idea anyway. Because we could have fast machines and disks that defeat even the best time resolution. > --- > Timestamp: Do we really need time? That could fail due to clock skew, if the values are modified from different machines. Wouldn't just a single "generation number", that keeps only increasing, be enough?