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: Redisplay slower in Emacs 28 than Emacs 27 Date: Tue, 08 Dec 2020 19:36:52 +0200 Message-ID: <83v9dc5he3.fsf@gnu.org> References: <877dptiro7.fsf@gnus.org> <87pn3lhcdd.fsf@gnus.org> <878sa9hbe2.fsf@gnus.org> <877dptfvae.fsf@gnus.org> <83czzl8qwu.fsf@gnu.org> <87sg8h78s8.fsf@gnus.org> <837dpt8lk5.fsf@gnu.org> <87pn3kjssr.fsf@gnus.org> <83im9c70vu.fsf@gnu.org> <87im9cfeej.fsf@gnus.org> <837dps6xyv.fsf@gnu.org> <87czzkdx57.fsf@gnus.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="11129"; mail-complaints-to="usenet@ciao.gmane.io" Cc: ghe@sdf.org, emacs-devel@gnu.org To: Lars Ingebrigtsen Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Dec 08 18:39:11 2020 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 1kmgxC-0002o7-Jz for ged-emacs-devel@m.gmane-mx.org; Tue, 08 Dec 2020 18:39:10 +0100 Original-Received: from localhost ([::1]:37886 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kmgxB-0006To-M2 for ged-emacs-devel@m.gmane-mx.org; Tue, 08 Dec 2020 12:39:09 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:50640) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kmgv6-0005Ro-HD for emacs-devel@gnu.org; Tue, 08 Dec 2020 12:37:00 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:55291) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kmgv5-0002cb-19; Tue, 08 Dec 2020 12:36:59 -0500 Original-Received: from [176.228.60.248] (port=1534 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1kmgv4-000872-Ga; Tue, 08 Dec 2020 12:36:58 -0500 In-Reply-To: <87czzkdx57.fsf@gnus.org> (message from Lars Ingebrigtsen on Tue, 08 Dec 2020 18:29:24 +0100) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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:260574 Archived-At: > From: Lars Ingebrigtsen > Cc: ghe@sdf.org, emacs-devel@gnu.org > Date: Tue, 08 Dec 2020 18:29:24 +0100 > > > I don't think I follow: since an image spec can (and usually does) > > include a file name, how can we use EQ? That would mean identical > > file names will cause us to think an image isn't cached, right? Or > > what am I missing? > > I'm not sure -- I don't quite understand what you mean here. > > Here's a spec: > > (setq spec '(image :type "xpm" :file "/tmp/foo.xpm")) > > Every time spec `spec' is redisplayed, EQ (spec, spec) will be true. Not if the list is re-assembled again, right? > We'd be going by "object identity" of the spec, and not looking at the > contents at all. > > I.e., we'd start treating image specs as (immutable) objects (to make > redisplay more efficient). It may make redisplay faster, but it will produce confusing effects if an identical spec is constructed from the same or identical elements: Emacs will think the image is not in the cache. Sounds like a lot to pay for a minor speedup, to say nothing of backward compatibility.