Package: emacs;
Reported by: Ergus <spacibba <at> aol.com>
Date: Tue, 20 May 2025 23:34:02 UTC
Severity: normal
Tags: fixed
Found in version 31.0.50
Done: Eli Zaretskii <eliz <at> gnu.org>
View this message in rfc822 format
From: Eli Zaretskii <eliz <at> gnu.org> To: Juri Linkov <juri <at> linkov.net> Cc: spacibba <at> aol.com, 78520 <at> debbugs.gnu.org Subject: bug#78520: 31.0.50; Performance issue in dired+isearch with dired-isearch-filenames Date: Thu, 22 May 2025 10:41:21 +0300
> From: Juri Linkov <juri <at> linkov.net>
> Cc: 78520 <at> debbugs.gnu.org, spacibba <at> aol.com
> Date: Thu, 22 May 2025 09:33:20 +0300
>
> >> When you customize `dired-isearch-filenames` to non-nil, it uses
> >> `next-single-property-change` to restrict matches to filenames.
> >
> > I guess this could be slow in a buffer with a lot of properties?
>
> In a Dired buffer the property 'dired-filename' is almost on every line.
>
> > Would it be possible to speed this up by searching as usual, but then
> > rejecting matches whose positions don't have the 'filename' property?
> > Or was this tried and found to be not faster?
>
> The currently implementation was intended to be quite fast,
> and indeed when I try it on a dir with thousands of files,
> isearch-lazy-highlight takes only 1 sec, even with thousands of matches.
> But apparently on slower hardware it's more slow.
I have fast hardware, but C-s for a match near the end of a Dired
buffer showing 5K files takes about 9 sec. This is in an unoptimized
build; an optimized build still takes 2.25 sec.
I'm not sure why you are talking about isearch-lazy-highlight, that's
not what the original report is about. C-s is slow even if I turn off
isearch-lazy-highlight, and the profile below in that case still
points to next-single-property-change as the hot spot.
> So unless someone wants to make an effort to optimize the
> implementation more, IMHO this could be closed.
Does isearch.el have some infrastructure for examining a match and
rejecting it if it doesn't meet some criteria? If so, can you point
me to that infrastructure?
Here's the profile I collected after turning off
isearch-lazy-highlight:
621 87% - ...
618 87% - isearch-search
618 87% - condition-case
618 87% - let
618 87% - while
618 87% - setq
618 87% - isearch-search-string
618 87% - let*
618 87% - save-excursion
618 87% - funcall
618 87% - #<byte-code-function 21A>
618 87% - apply
618 87% - search-within-boundaries
618 87% - let*
618 87% - while
311 43% - setq
311 43% - funcall
311 43% - #<interpreted-function E6E>
311 43% - let
311 43% - if
311 43% - mapcar
308 43% - #<interpreted-function D88>
308 43% next-single-property-change
3 0% - function
3 0% - cconv-make-interpreted-closure
2 0% cconv-fv
1 0% macroexpand-all
307 43% - if
303 42% - setq
302 42% - funcall
299 42% - #<interpreted-function E6E>
299 42% - let
298 42% - if
298 42% - mapcar
289 40% - #<interpreted-function 740>
289 40% next-single-property-change
8 1% - function
8 1% - cconv-make-interpreted-closure
3 0% - macroexpand-all
3 0% - macroexp--expand-all
3 0% - macroexp--all-forms
2 0% - macroexp--expand-all
2 0% - #<byte-code-function 83C>
2 0% - macroexp--all-forms
2 0% - macroexp--expand-all
2 0% macroexp-macroexpand
3 0% - cconv-fv
2 0% mapcar
1 0% - cconv-analyze-form
1 0% - cconv--analyze-function
1 0% - mapcar
1 0% #<byte-code-function F28>
3 0% - #<interpreted-function FDE>
2 0% - let
1 0% - funcall
1 0% re-search-forward
1 0% cond
4 0% - if
3 0% - progn
3 0% - if
2 0% goto-char
2 0% - completion-try-completion
2 0% - completion--nth-completion
2 0% - seq-some
2 0% - seq-do
2 0% - mapc
2 0% - #<byte-code-function B6E>
2 0% - #<byte-code-function BF2>
2 0% - eval
2 0% - let
2 0% - funcall
2 0% - #<byte-code-function C44>
1 0% - completion-pcm-try-completion
1 0% - completion-pcm--find-all-completions
1 0% - completion-pcm--all-completions
1 0% - all-completions
1 0% - #<byte-code-function AA0>
1 0% - complete-with-action
1 0% all-completions
1 0% - completion-basic-try-completion
1 0% - try-completion
1 0% - #<byte-code-function AA0>
1 0% - complete-with-action
1 0% try-completion
1 0% - funcall-interactively
1 0% - isearch-printing-char
1 0% - let
1 0% - if
1 0% - isearch-process-search-char
1 0% - let*
1 0% - isearch-process-search-string
1 0% - isearch-search-and-update
1 0% - isearch-update
1 0% - if
1 0% - progn
1 0% - if
1 0% - let
1 0% - setq
1 0% - pos-visible-in-window-group-p
1 0% pos-visible-in-window-p
68 9% Automatic GC
14 1% - command-execute
14 1% - call-interactively
14 1% - byte-code
14 1% - read-extended-command
14 1% - read-extended-command-1
14 1% - completing-read
14 1% - completing-read-default
14 1% - read-from-minibuffer
2 0% redisplay_internal (C function)
6 0% redisplay_internal (C function)
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