Re: [PATCH] Fix python-info-current-defun performance for large defuns

[Eli Zaretskii]

Ping!  Tom, could you please respond to the comments, and perhaps post
an updated patch?  I'd like to install this when it's ready.

Thanks.

> Date: Tue, 05 Sep 2023 23:17:48 +0900
> From: kobarity <kobarity@gmail.com>
> Cc: emacs-devel@gnu.org
> 
> 
> Eli Zaretskii wrote:
> > > From: Tom Gillespie <tgbugs@gmail.com>
> > > Date: Sun, 3 Sep 2023 18:37:34 -0700
> > > 
> > > Hi,
> > >    Here is a patch to fix a performance issue in
> > > python-info-current-defun that appears when the function
> > > is run on large defuns. The issue can appear to the user as a
> > > noticeable (~500ms) freeze when the point is in a large defun
> > > in a python buffer with which-function-mode enabled. More
> > > details in the commit message and comments in the code.
> > > 
> > > I made the patch against the emacs-29 branch, but will also
> > > on master without issue.
> > 
> > Thanks.
> > 
> > kobarity, any comments?
> 
> Hi,
> Thank you for the patch.  I have tried it and have confirmed that it
> improves performance.  I think that not using the time-consuming
> `python-nav-end-of-defun' has helped.
> 
> However, I found one unexpected behavior.  The following code is an
> example added as an ERT:
> 
> def a():
>     def b(): return
>     if True:
>         def c(): return
> 
> if True:
>     if True:
>         def d(): return
> 
> In this example, `python-info-current-defun' seems to return "a" if
> the point is on the second line from the bottom.  Could you please
> take a look?
> 
> My personal impression is that 114 characters per line is a bit long.
>