From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Lars Ingebrigtsen Newsgroups: gmane.emacs.bugs Subject: bug#22763: 25.1.50; Feature Request -- A faster method to obtain line number at position. Date: Sun, 07 Feb 2021 20:46:37 +0100 Message-ID: <87zh0fy82q.fsf@gnus.org> References: <83y4aclofm.fsf@gnu.org> <878s7z532u.fsf@gnus.org> <87y2fz3lpe.fsf@gnus.org> <87h7mn22ls.fsf@gnus.org> <83eehrn408.fsf@gnu.org> <87y2fzzqxb.fsf@gnus.org> <87tuqnzqh2.fsf@gnus.org> <83blcvn1ku.fsf@gnu.org> <87czxbznly.fsf@gnus.org> <834kinmzpy.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="24411"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: 22763@debbugs.gnu.org, esq@lawlist.com, monnier@iro.umontreal.ca To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun Feb 07 20:47:27 2021 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 1l8q1n-0006EV-5C for geb-bug-gnu-emacs@m.gmane-mx.org; 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Original-Received: from cm-84.212.202.86.getinternet.no ([84.212.202.86] helo=xo) by quimby.gnus.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l8q11-0004C6-3S; Sun, 07 Feb 2021 20:46:46 +0100 Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwBAMAAAClLOS0AAAABGdBTUEAALGPC/xhBQAAACBj SFJNAAB6JgAAgIQAAPoAAACA6AAAdTAAAOpgAAA6mAAAF3CculE8AAAAElBMVEWeeVengF2qh2dZ RjUrIhv///+8ThgcAAAAAWJLR0QF+G/pxwAAAAd0SU1FB+UCBxMrID40i8AAAAGPSURBVDjLhZPt ccMwCIaRnQEkTSCpC6iBAXwH+89U0JcV93olP5Lw+IUXLIELIfgAWwQLAAPB90wHbiSC61+hWHhw CrzTlO9PlRHe/vie1YilbOQGLpe8keCXkU1RsrqYdkLYQEkhuNH5I1/KHCA+QR4g59hbJ7ckBg79 0fNU4w5mnURcVy2bc4yQT+F6fIBStEKCExEnMXDEBgCQhRFu0PslMIXMLnkBNaGVUK4blAlEBOk6 1o5nJaBTCc/uG2i22C9FnKCe9aQbuDyB9iCp0y+4OJQnK2E/XIatFJPIBUvRd2jzqUAuD7/sEtkc 9QZToZUYBOFzjtI2hafg+wE0XxFILhwvpIOERIwqEE7HBGaXzJEw6adCHkCf+JIt8GinoYHXTJoS 6wBuVtJ8VUSslZxdopJWlbd6Fn0lyRQQV4taCVVzFN+Am4DYVoz0zu12ArwWcNBA6kfULSBH1IXR Ne6UG6Z0i7WgjTlvmgFuissUrwXu8a6sbwXFPYDq6g7OfVNi4Psf8HoAtrPyN/gB2wyV1l0kvbkA AAAldEVYdGRhdGU6Y3JlYXRlADIwMjEtMDItMDdUMTk6NDM6MzErMDA6MDD7ddP+AAAAJXRFWHRk YXRlOm1vZGlmeQAyMDIxLTAyLTA3VDE5OjQzOjMxKzAwOjAwiihrQgAAAABJRU5ErkJggg== X-Now-Playing: Laraaji's _Sun Transformations_: "Ocean Flow Zither (Mia Doi Todd Remix)" In-Reply-To: <834kinmzpy.fsf@gnu.org> (Eli Zaretskii's message of "Sun, 07 Feb 2021 21:42:33 +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" Xref: news.gmane.io gmane.emacs.bugs:199553 Archived-At: Eli Zaretskii writes: >> (with-temp-buffer >> (dotimes (_ 1000) >> (insert-file-contents "~/src/emacs/trunk/src/ChangeLog.11") >> (goto-char (point-max))) >> (benchmark-run 1 >> (dotimes (i 100) >> (goto-char (* (/ (buffer-size) 100) i)) >> (line-number-at-pos (point))))) >> >> (Adjusted down to 100, because it takes too long.) Let's see... >> >> Yup, still 10x faster. > > This one traverses each 1/100th region of the file just once, no? Did I write it wrong again? (dotimes (i 100) (goto-char (* (/ (buffer-size) 100) i)) (line-number-at-pos (point))))) No, that should be the entire buffer, spread out evenly? >> OK, I've now bumped the benchmark-run to 10 (and decreased the buffer >> size by a factor of 10)... let's see... The new version takes exactly >> the same amount of time, of course... >> >> And so does the old one. Well, it's 10% faster in this? > > 10% or 10-fold? 10%. >> And in buffers with lines with normal line lengths, it's 10x slower? > > In my benchmarks some years ago it was about twice slower, not 10 > times. Perhaps memchr has gotten faster over the years? Using larger memory fetches and stuff? -- (domestic pets only, the antidote for overdose, milk.) bloggy blog: http://lars.ingebrigtsen.no