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

[kobarity]

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.