all messages for Emacs-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
From: Lars Ingebrigtsen <larsi@gnus.org>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 22763@debbugs.gnu.org, esq@lawlist.com, monnier@iro.umontreal.ca
Subject: bug#22763: 25.1.50; Feature Request -- A faster method to obtain line number at position.
Date: Sun, 07 Feb 2021 19:23:53 +0100	[thread overview]
Message-ID: <87tuqnzqh2.fsf@gnus.org> (raw)
In-Reply-To: <87y2fzzqxb.fsf@gnus.org> (Lars Ingebrigtsen's message of "Sun, 07 Feb 2021 19:14:08 +0100")

Lars Ingebrigtsen <larsi@gnus.org> writes:

>> find_newline does the same as display_count_lines: it calls memchr.
>> But it also maintains a newline cache.  If you disable that cache (by
>> turning of cache-long-scans), you might see a different speedup.
>
> Shouldn't the cache speed things up?

No, you're right -- if I set `cache-long-scans' to nil and
`line-number-at-pos' in Emacs 27 becomes ~8x faster in my test, which is
currently

(with-temp-buffer
  (setq cache-long-scans nil)
  (dotimes (_ 1000)
    (insert-file-contents "~/src/emacs/trunk/src/ChangeLog.11")
    (goto-char (point-max)))
  (benchmark-run 1
    (dotimes (i 1000)
      (goto-char (/ (buffer-size) 1000))
      (line-number-at-pos (point)))))

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no





  reply	other threads:[~2021-02-07 18:23 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-22  2:42 bug#22763: 25.1.50; Feature Request -- A faster method to obtain line number at position Keith David Bershatsky
2016-02-22 16:06 ` Eli Zaretskii
2021-02-07 15:07   ` Lars Ingebrigtsen
2021-02-07 15:44     ` Lars Ingebrigtsen
2021-02-07 16:07     ` Lars Ingebrigtsen
2021-02-07 17:40       ` Stefan Monnier
2021-02-07 17:45         ` Lars Ingebrigtsen
2021-02-07 18:07           ` Lars Ingebrigtsen
2021-02-07 18:09           ` Eli Zaretskii
2021-02-07 18:14             ` Lars Ingebrigtsen
2021-02-07 18:23               ` Lars Ingebrigtsen [this message]
2021-02-07 19:02                 ` Eli Zaretskii
2021-02-07 19:06                   ` Eli Zaretskii
2021-02-07 19:25                   ` Lars Ingebrigtsen
2021-02-07 19:34                     ` Lars Ingebrigtsen
2021-02-07 19:43                       ` Eli Zaretskii
2021-02-07 19:42                     ` Eli Zaretskii
2021-02-07 19:46                       ` Lars Ingebrigtsen
2021-02-07 19:52                         ` Eli Zaretskii
2021-02-07 21:52                           ` Lars Ingebrigtsen
2021-02-07 21:58                             ` Lars Ingebrigtsen
2021-02-08  3:34                               ` Eli Zaretskii
2021-02-07 22:09                             ` Philipp
2021-02-07 20:37                     ` Stefan Monnier
2021-02-07 20:42                       ` Lars Ingebrigtsen
2021-02-07 20:50                         ` Eli Zaretskii
2021-02-07 21:36                           ` Lars Ingebrigtsen
2021-02-08 15:04                             ` Eli Zaretskii
2021-02-09  2:17                               ` Katsumi Yamaoka
2021-02-09  7:13                                 ` Lars Ingebrigtsen
2021-05-19 23:55 ` Ben Levy via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-05-20  6:45   ` Eli Zaretskii
2021-05-20  7:27     ` Andreas Schwab
2021-05-20  7:35       ` Ben Levy via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-05-20  9:08         ` Eli Zaretskii
2021-05-20  9:03       ` Eli Zaretskii
2021-05-20 19:53 ` Ben Levy via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-05-20 20:09   ` Eli Zaretskii
2021-05-20 20:40 ` Ben Levy via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-05-21  5:46   ` Eli Zaretskii

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87tuqnzqh2.fsf@gnus.org \
    --to=larsi@gnus.org \
    --cc=22763@debbugs.gnu.org \
    --cc=eliz@gnu.org \
    --cc=esq@lawlist.com \
    --cc=monnier@iro.umontreal.ca \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this external index

	https://git.savannah.gnu.org/cgit/emacs.git
	https://git.savannah.gnu.org/cgit/emacs/org-mode.git

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.