From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings Newsgroups: gmane.emacs.bugs Subject: bug#56682: Fix the long lines font locking related slowdowns Date: Tue, 02 Aug 2022 21:26:31 +0000 Message-ID: <74ddc877f1e81f399eea@heytings.org> References: <05388e8d8812bfa3695d@heytings.org> <83v8rf5894.fsf@gnu.org> <65cb7c73fd4a999cca00@heytings.org> <8c7321f2f3400a5db9be@heytings.org> <8c7321f2f388e5343475@heytings.org> <6ea376f6-d503-06d8-6d83-50c52b695394@yandex.ru> <8c7321f2f3ac52bfee4b@heytings.org> <8c7321f2f3ec1ef81af9@heytings.org> <02e83b0e-1b5c-fe75-6e59-1f8ddff82d37@yandex.ru> <96f28fd8-6744-1925-0631-0095099362dd@yandex.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="27946"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 56682@debbugs.gnu.org, Eli Zaretskii , Dmitry Gutov To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Tue Aug 02 23:27:13 2022 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1oIzQ0-00074F-ER for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 02 Aug 2022 23:27:12 +0200 Original-Received: from localhost ([::1]:52414 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oIzPy-00058O-TA for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 02 Aug 2022 17:27:10 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:41450) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oIzPq-00058C-Bz for bug-gnu-emacs@gnu.org; Tue, 02 Aug 2022 17:27:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:55480) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1oIzPq-0003eC-3a for bug-gnu-emacs@gnu.org; Tue, 02 Aug 2022 17:27:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1oIzPp-0002cG-PF for bug-gnu-emacs@gnu.org; Tue, 02 Aug 2022 17:27:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Gregory Heytings Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 02 Aug 2022 21:27:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 56682 X-GNU-PR-Package: emacs Original-Received: via spool by 56682-submit@debbugs.gnu.org id=B56682.165947559510020 (code B ref 56682); Tue, 02 Aug 2022 21:27:01 +0000 Original-Received: (at 56682) by debbugs.gnu.org; 2 Aug 2022 21:26:35 +0000 Original-Received: from localhost ([127.0.0.1]:45229 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1oIzPO-0002bX-Jx for submit@debbugs.gnu.org; Tue, 02 Aug 2022 17:26:34 -0400 Original-Received: from heytings.org ([95.142.160.155]:36064) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1oIzPM-0002bP-Qo for 56682@debbugs.gnu.org; Tue, 02 Aug 2022 17:26:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heytings.org; s=20220101; t=1659475591; bh=hdkwv85vYULuGwpWWYE/e+jelhdnJe6zShrlkaKA5Ok=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:From; b=vwdWEJn/9w6c0qRypUHB/HYDCsL63nBYHrijpziDpjAfkla/S7up2R56yncdKOFzA W6FGDADAvQVR02crum6ZrLz4B4ZoVNtumcOGEN765srKDz9u3eEHiVEtbb/70oIcVo hKUh/M0zJ1ELaKB11ZnWKjhM1GdKeiR7xzMS9O+izvrcJTbsVPhzs1Ckirq0oyTn9T zkqJjbMlMgO0bV6JY3rQ2YtmtK3OmrEIpp00b8BqBl28/VJjQB7/46GmtqKMTSFgdB AS3G7IPRkE0bHLyox0nGpw2ZVvSsXs8RkUIdcrCZW1VwzhTSut83tw69lmqvglZII9 3tPpIXAXhVsDQ== In-Reply-To: X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:238586 Archived-At: >> It is necessary to add a locked narrowing around >> fontification-functions and pre/post-command-hook to ensure that Emacs >> remains responsive. > > It's neither necessary (it's perfectly possible to do something quickly > that just needs to look at the first few lines of the buffer to decide > in which way to parse the nearby surrounding bytes, for example) nor > sufficient (it's easy to spend minutes wasting time running in circles > because of a bug, e.g. a bug triggered by the fact that the "unusual" > nature of the visible part of the buffer after an arbitrary narrowing). > You're a mathematician, aren't you? I'm not speaking of mathematical (i.e. absolute) necessity here, but of a practical necessity. And I did not say (or thought) that it is sufficient.