From: Eli Zaretskii <eliz@gnu.org>
To: Lars Ingebrigtsen <larsi@gnus.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: Mon, 08 Feb 2021 17:04:58 +0200 [thread overview]
Message-ID: <83pn1alhwl.fsf@gnu.org> (raw)
In-Reply-To: <87zh0fwofn.fsf@gnus.org> (message from Lars Ingebrigtsen on Sun, 07 Feb 2021 22:36:12 +0100)
> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: monnier@iro.umontreal.ca, 22763@debbugs.gnu.org, esq@lawlist.com
> Date: Sun, 07 Feb 2021 22:36:12 +0100
>
> > It exists to support the line-number display on the mode line. That
> > display has its own cache, as part of the window object, so
> > display_count_lines very rarely needs to count from the beginning of
> > the buffer, it usually counts from the last place it stopped the
> > previous time for the same window. This is why it has the signature
> > that it has.
>
> But these are the signatures:
>
> ptrdiff_t
> find_newline (ptrdiff_t start, ptrdiff_t start_byte, ptrdiff_t end,
> ptrdiff_t end_byte, ptrdiff_t count, ptrdiff_t *counted,
> ptrdiff_t *bytepos, bool allow_quit)
>
>
> static ptrdiff_t
> display_count_lines (ptrdiff_t start_byte,
> ptrdiff_t limit_byte, ptrdiff_t count,
> ptrdiff_t *byte_pos_ptr)
>
> So they seem very similar...
I was trying to explain why display_count_lines accepts arguments that
may seem unnecessary at first sight if the job is to just count the
lines.
> Anyway, here's something that just occurred to me: It's still the plan
> to have so-long-mode on by default, right? Which means that
> 'buffer-line-statistics' will be called when opening a file, which means
> that we know whether there are any long lines in the buffer.
>
> Could we use this info to switch between cached and non-cached action
> for find_newline? (I.e., just set 'cache-long-scans'.)
It isn't as easy as it may sound, because cache-long-scans also
affects another cache, the one used by bidi.c. We need to be able to
turn them on and off separately to be able to support what you
suggest.
> Conversely, could we use find_newline to trigger so-long-mode? Today,
> so-long-mode isn't able to step into the fray when something plops a
> long line into the buffer (in shell-mode, for instance). If
> find_newline finds a long line, it could switch 'cache-long-scans' on,
> and also (on perhaps a different threshold) notify so-long-mode?
We already detect overlong lines: that's when the line number on the
mode line becomes "??". We just need to use that as trigger for
so-long-mode, if we want it to turn on automatically. Also, we need
to consider whether the same threshold as the one we use for the
mode-line display of line numbers is suitable for so-long-mode, or we
need two separate thresholds.
next prev parent reply other threads:[~2021-02-08 15:04 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
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 [this message]
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
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