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.bugs Subject: bug#60953: The :match predicate with large regexp in tree-sitter font-lock seems inefficient Date: Wed, 25 Jan 2023 14:49:59 +0200 Message-ID: <83wn5ag4nc.fsf@gnu.org> References: <7624dddc-4600-9a03-ac8b-d3c9e0ab618c@yandex.ru> <04729838-b7d4-8a08-2b71-12536a28aebb@yandex.ru> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="22464"; mail-complaints-to="usenet@ciao.gmane.io" Cc: casouri@gmail.com, 60953@debbugs.gnu.org To: Dmitry Gutov Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Jan 25 13:50:27 2023 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 1pKfER-0005g3-Ev for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 25 Jan 2023 13:50:27 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pKfE6-0007fw-TB; Wed, 25 Jan 2023 07:50:06 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pKfE2-0007fa-Nc for bug-gnu-emacs@gnu.org; Wed, 25 Jan 2023 07:50:02 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pKfE2-0005KS-8U for bug-gnu-emacs@gnu.org; Wed, 25 Jan 2023 07:50:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1pKfE1-0006nG-Pz for bug-gnu-emacs@gnu.org; Wed, 25 Jan 2023 07:50:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 25 Jan 2023 12:50:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 60953 X-GNU-PR-Package: emacs Original-Received: via spool by 60953-submit@debbugs.gnu.org id=B60953.167465099626095 (code B ref 60953); Wed, 25 Jan 2023 12:50:01 +0000 Original-Received: (at 60953) by debbugs.gnu.org; 25 Jan 2023 12:49:56 +0000 Original-Received: from localhost ([127.0.0.1]:58568 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pKfDv-0006mm-OY for submit@debbugs.gnu.org; Wed, 25 Jan 2023 07:49:56 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:52420) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pKfDt-0006mW-1T for 60953@debbugs.gnu.org; Wed, 25 Jan 2023 07:49:54 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pKfDn-0005Hw-EK; Wed, 25 Jan 2023 07:49:47 -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=HCBveevOT6IDrey944hhxzPO90v1QN2kvEJJY7mSGRs=; b=APk6a+KLz69C 2LmUjS3JaZe0Bw7vIt84bmWLcuqO5MKAF4RwGkSzu0VAhqvyBUlsaOV7OWrJImvAGs/6UW3/56wzG nUZGR++f7tvj8kPgrkNBavIv2dEswsZiw2Sy2fc8rifjrJdBDEJbYMMt8iuUGDcPR20EKNs/y3/Vz rWJNnfoxwAOJfggC9hKMcwMq2S3GcIaWCjNanTPvw9YtUAiVV6N+TiuWsGcBLXXd9Rdf/JxkRPSN9 1RPO49FEi/B6H1OaejsKDCwo6b3aoaLvyZA0fZgDEXp5ZyWnzPer5lZ8/A+20W871ZiijPoVTX1Zg 2azxciqPaJe0dv4hrdbJ8w==; Original-Received: from [87.69.77.57] (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 1pKfDm-0003JD-PR; Wed, 25 Jan 2023 07:49:47 -0500 In-Reply-To: (message from Dmitry Gutov on Wed, 25 Jan 2023 05:48:13 +0200) 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-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:254119 Archived-At: > Cc: 60953@debbugs.gnu.org > Date: Wed, 25 Jan 2023 05:48:13 +0200 > From: Dmitry Gutov > > > We can probably match the regexp in-place, just limit the match to the range of the node. > > That's what I tried to do in the patch attached to the first message: > https://debbugs.gnu.org/cgi/bugreport.cgi?bug=60953#5 > > But the effect on performance was surprisingly hard to notice. It also > broke the actual highlighting, but that's probably because the regexp > uses anchors \` and \', which don't really work for fast_looking_at > calls inside a buffer. The condition for a match in that patch is not correct, AFAIU: if (val >= 0) return true; else return false; It should be "if (val > 0)" instead, since fast_looking_at returns the number of characters that matched (unlike fast_string_match in the original code, which returns the _index_ of the match). Also, fast_string_match is capable of succeeding if the match begins not at the first character, whereas fast_looking_at does an anchored match. Do we expect the text to match from its beginning in this case? If not, I think the replacement didn't do what the original code does, and you should have used search_buffer or maybe search_buffer_re instead.