From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: =?ISO-8859-1?Q?Nordl=F6w?= Newsgroups: gmane.emacs.help Subject: Strange performance hit for insert-file-contents-literally() Date: Thu, 26 Nov 2009 23:58:10 -0800 (PST) Organization: http://groups.google.com Message-ID: NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1259311253 25602 80.91.229.12 (27 Nov 2009 08:40:53 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 27 Nov 2009 08:40:53 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Nov 27 09:40:46 2009 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1NDwNi-0000mh-Av for geh-help-gnu-emacs@m.gmane.org; Fri, 27 Nov 2009 09:40:46 +0100 Original-Received: from localhost ([127.0.0.1]:48937 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NDwNh-0005Bh-Hk for geh-help-gnu-emacs@m.gmane.org; Fri, 27 Nov 2009 03:40:45 -0500 Original-Path: news.stanford.edu!usenet.stanford.edu!news.isc.org!news.glorb.com!postnews.google.com!a32g2000yqm.googlegroups.com!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 35 Original-NNTP-Posting-Host: 81.170.219.22 Original-X-Trace: posting.google.com 1259308690 6754 127.0.0.1 (27 Nov 2009 07:58:10 GMT) Original-X-Complaints-To: groups-abuse@google.com Original-NNTP-Posting-Date: Fri, 27 Nov 2009 07:58:10 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: a32g2000yqm.googlegroups.com; posting-host=81.170.219.22; posting-account=ytJKAgoAAAA1tg4ScoRszebXiIldA5vg User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (X11; U; Linux i686; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Chrome/4.0.257.0 Safari/532.5,gzip(gfe),gzip(gfe) Original-Xref: news.stanford.edu gnu.emacs.help:175101 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:70176 Archived-At: I am implementing a package for doing recursive file system magic- detect and scan/search/grep for pattern. In this process I have stumbled across a strange performance problem; If I want to grep for raw binary (literal) patterns, I thought that (benchmark-run 1 (with-temp-buffer (buffer-disable-undo) (insert- file-contents-literally "~/pnw.tar.gz" nil))) would given optimal performance but it turns out that (benchmark-run 1 (save-excursion (set-buffer (find-file-noselect "~/ pnw.tar.gz" t t)))) is about 11 times faster on my laptop PC (the first time its called of course, the second time it reuses the open buffer so that doesn't count)!. As find-file-noselect() uses insert-file-contents-literally() it must disable some stuff that find-file-literally() doesn't. The question is what? I would prefer no to be forced to use find-file-noselect() as this does other unneccessary stuff I don't need. It also reuses the buffer if its already open which is not always what I want with compressed files for example. My logic namely detects the file magic headers for compressed files and then reopens them non-literally using jka-compr in order to detect their underlying (decompressed) type like the unix program "file" does. Is this maybe a bug? I am currently using Emacs CVS. Thanks in advance for all tips, Nordl=F6w