bug#59678: [PATCH] sh-script: use completion-table-with-cache to improve performance

bug#59678: [PATCH] sh-script: use completion-table-with-cache to improve performance

[yikai]

Hi,

I found that the auto-completion on .sh files (with company-mode) was pretty slow (takes several seconds).
It turns out that company-mode would call the capf function with 'metadata action for each candidate,
where each function call would need to list all the cmds. In this patch, I modified the code to use
completion-table-with-cache which fixes the problem for me.



---
 lisp/progmodes/sh-script.el | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index 408ebfc0451..188b3b73125 100644
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -1688,19 +1688,17 @@ sh--vars-before-point
 ;; (defun sh--var-completion-table (string pred action)
 ;;   (complete-with-action action (sh--vars-before-point) string pred))
 
-(defun sh--cmd-completion-table (string pred action)
-  (let ((cmds
-         (append (when (fboundp 'imenu--make-index-alist)
-                   (mapcar #'car
-                           (condition-case nil
-                               (imenu--make-index-alist)
-                             (imenu-unavailable nil))))
-                 (mapcar (lambda (v) (concat v "="))
-                         (sh--vars-before-point))
-                 (locate-file-completion-table
-                  exec-path exec-suffixes string pred t)
-                 sh--completion-keywords)))
-    (complete-with-action action cmds string pred)))
+(defun sh--cmd-completion-table-gen (string)
+  (append (when (fboundp 'imenu--make-index-alist)
+            (mapcar #'car
+                    (condition-case nil
+                        (imenu--make-index-alist)
+                      (imenu-unavailable nil))))
+          (mapcar (lambda (v) (concat v "="))
+                  (sh--vars-before-point))
+          (locate-file-completion-table
+           exec-path exec-suffixes string nil t)
+          sh--completion-keywords))
 
 (defun sh-completion-at-point-function ()
   (save-excursion
@@ -1713,7 +1711,7 @@ sh-completion-at-point-function
         (list start end (sh--vars-before-point)
               :company-kind (lambda (_) 'variable)))
        ((sh-smie--keyword-p)
-        (list start end #'sh--cmd-completion-table
+        (list start end (completion-table-with-cache #'sh--cmd-completion-table-gen)
               :company-kind
               (lambda (s)
                 (cond
-- 
2.38.1

bug#59678: [PATCH] sh-script: use completion-table-with-cache to improve performance

[Eli Zaretskii]

> Cc: Yikai Zhao <yikai@z1k.dev>
> From: yikai@z1k.dev
> Date: Tue, 29 Nov 2022 22:30:14 +0800
> 
> Hi,
> 
> I found that the auto-completion on .sh files (with company-mode) was pretty slow (takes several seconds).
> It turns out that company-mode would call the capf function with 'metadata action for each candidate,
> where each function call would need to list all the cmds. In this patch, I modified the code to use
> completion-table-with-cache which fixes the problem for me.

Stefan, any comments?

>  lisp/progmodes/sh-script.el | 26 ++++++++++++--------------
>  1 file changed, 12 insertions(+), 14 deletions(-)
> 
> diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
> index 408ebfc0451..188b3b73125 100644
> --- a/lisp/progmodes/sh-script.el
> +++ b/lisp/progmodes/sh-script.el
> @@ -1688,19 +1688,17 @@ sh--vars-before-point
>  ;; (defun sh--var-completion-table (string pred action)
>  ;;   (complete-with-action action (sh--vars-before-point) string pred))
>  
> -(defun sh--cmd-completion-table (string pred action)
> -  (let ((cmds
> -         (append (when (fboundp 'imenu--make-index-alist)
> -                   (mapcar #'car
> -                           (condition-case nil
> -                               (imenu--make-index-alist)
> -                             (imenu-unavailable nil))))
> -                 (mapcar (lambda (v) (concat v "="))
> -                         (sh--vars-before-point))
> -                 (locate-file-completion-table
> -                  exec-path exec-suffixes string pred t)
> -                 sh--completion-keywords)))
> -    (complete-with-action action cmds string pred)))
> +(defun sh--cmd-completion-table-gen (string)
> +  (append (when (fboundp 'imenu--make-index-alist)
> +            (mapcar #'car
> +                    (condition-case nil
> +                        (imenu--make-index-alist)
> +                      (imenu-unavailable nil))))
> +          (mapcar (lambda (v) (concat v "="))
> +                  (sh--vars-before-point))
> +          (locate-file-completion-table
> +           exec-path exec-suffixes string nil t)
> +          sh--completion-keywords))
>  
>  (defun sh-completion-at-point-function ()
>    (save-excursion
> @@ -1713,7 +1711,7 @@ sh-completion-at-point-function
>          (list start end (sh--vars-before-point)
>                :company-kind (lambda (_) 'variable)))
>         ((sh-smie--keyword-p)
> -        (list start end #'sh--cmd-completion-table
> +        (list start end (completion-table-with-cache #'sh--cmd-completion-table-gen)
>                :company-kind
>                (lambda (s)
>                  (cond
> -- 
> 2.38.1
> 
> 
> 
> 
> 

bug#59678: [PATCH] sh-script: use completion-table-with-cache to improve performance

[Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors]

>> I found that the auto-completion on .sh files (with company-mode) was
>> pretty slow (takes several seconds).  It turns out that company-mode
>> would call the capf function with 'metadata action for each
>> candidate, where each function call would need to list all the
>> cmds. In this patch, I modified the code to use
>> completion-table-with-cache which fixes the problem for me.
>
> Stefan, any comments?

Looks OK to me.  The description of the problem looks concerning, tho:
if Company really calls the completion table with `metadata` once per
candidate, then there's a bug in company.


        Stefan

bug#59678: [PATCH] sh-script: use completion-table-with-cache to improve performance

[Eli Zaretskii]

> Cc: Yikai Zhao <yikai@z1k.dev>
> From: yikai@z1k.dev
> Date: Tue, 29 Nov 2022 22:30:14 +0800
> 
> Hi,
> 
> I found that the auto-completion on .sh files (with company-mode) was pretty slow (takes several seconds).
> It turns out that company-mode would call the capf function with 'metadata action for each candidate,
> where each function call would need to list all the cmds. In this patch, I modified the code to use
> completion-table-with-cache which fixes the problem for me.

Thanks, installed on the emacs-29 branch.

In the future, please accompany your changes with ChangeLog-style commit of
messages (see CONTRIBUTE for the details).

bug#59678: [PATCH] sh-script: use completion-table-with-cache to improve performance

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: yikai@z1k.dev,  59678@debbugs.gnu.org
> Date: Thu, 01 Dec 2022 15:30:04 -0500
> 
> >> I found that the auto-completion on .sh files (with company-mode) was
> >> pretty slow (takes several seconds).  It turns out that company-mode
> >> would call the capf function with 'metadata action for each
> >> candidate, where each function call would need to list all the
> >> cmds. In this patch, I modified the code to use
> >> completion-table-with-cache which fixes the problem for me.
> >
> > Stefan, any comments?
> 
> Looks OK to me.  The description of the problem looks concerning, tho:
> if Company really calls the completion table with `metadata` once per
> candidate, then there's a bug in company.

Thanks, I therefore installed the changes.

bug#59678: [PATCH] sh-script: use completion-table-with-cache to improve performance

[Yikai Zhao]

On Fri, Dec 2, 2022 at 9:44 PM Eli Zaretskii <eliz@gnu.org> wrote:
>
> > Cc: Yikai Zhao <yikai@z1k.dev>
> > From: yikai@z1k.dev
> > Date: Tue, 29 Nov 2022 22:30:14 +0800
> >
> > Hi,
> >
> > I found that the auto-completion on .sh files (with company-mode) was pretty slow (takes several seconds).
> > It turns out that company-mode would call the capf function with 'metadata action for each candidate,
> > where each function call would need to list all the cmds. In this patch, I modified the code to use
> > completion-table-with-cache which fixes the problem for me.
>
> Thanks, installed on the emacs-29 branch.
>
> In the future, please accompany your changes with ChangeLog-style commit of
> messages (see CONTRIBUTE for the details).

Thanks. I will do that next time.

bug#59678: [PATCH] sh-script: use completion-table-with-cache to improve performance

[Yikai Zhao]

On Fri, Dec 2, 2022 at 4:30 AM Stefan Monnier <monnier@iro.umontreal.ca> wrote:
>
> >> I found that the auto-completion on .sh files (with company-mode) was
> >> pretty slow (takes several seconds).  It turns out that company-mode
> >> would call the capf function with 'metadata action for each
> >> candidate, where each function call would need to list all the
> >> cmds. In this patch, I modified the code to use
> >> completion-table-with-cache which fixes the problem for me.
> >
> > Stefan, any comments?
>
> Looks OK to me.  The description of the problem looks concerning, tho:
> if Company really calls the completion table with `metadata` once per
> candidate, then there's a bug in company.

Thanks!

I again confirmed that this is the current behavior.

I created an issue for company-mode to follow up.
https://github.com/company-mode/company-mode/issues/1351

>
>
>         Stefan
>