How to speed up the invocation of an event?

[Yurii-huang]

I see that calling event is taking too long. And this is especially true on low-performance machines. For example, I use the keys to switch components.

cProfile

[root@DAS-OS installer-menu]# python3 -m cProfile -s cumulative src/main.py
src/network.py:25: PyGIWarning: NM was imported without specifying a version first. Use gi.require_version('NM', '1.0') before import to ensure that the right version gets loaded.
  from gi.repository import NM
third_party_site /root/installer-menu/src/third_party/usr/lib/python3.7/site-packages
kernel encrypt device support: False
Please wait starting blivet...
         10154593 function calls (10106438 primitive calls) in 10.850 seconds

   Ordered by: cumulative time

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
    851/1    0.020    0.000   10.895   10.895 {built-in method builtins.exec}
        1    0.000    0.000   10.895   10.895 main.py:2(<module>)
        1    0.000    0.000    9.362    9.362 app.py:1405(run)
        1    0.000    0.000    9.362    9.362 base_events.py:551(run_until_complete)
        1    0.000    0.000    9.362    9.362 base_events.py:528(run_forever)
      259    0.005    0.000    9.361    0.036 base_events.py:1690(_run_once)
     1081    0.002    0.000    7.259    0.007 events.py:86(_run)
     1081    0.003    0.000    7.258    0.007 {method 'run' of 'Context' objects}
1924/1709    0.006    0.000    6.973    0.004 _callback.py:40(invoke)
1924/1709    0.007    0.000    6.968    0.004 _callback.py:23(_invoke)
1879/1799    0.013    0.000    6.128    0.003 message_pump.py:595(_dispatch_message)
     1496    0.013    0.000    6.085    0.004 message_pump.py:686(_on_message)
     1071    0.001    0.000    6.054    0.006 message_pump.py:678(on_event)
      462    0.019    0.000    5.731    0.012 message_pump.py:524(_process_messages_loop)
 1478/508    0.241    0.000    5.278    0.010 stylesheet.py:415(apply)
      180    0.006    0.000    4.953    0.028 stylesheet.py:630(update_nodes)
      447    0.001    0.000    4.890    0.011 message_pump.py:480(_process_messages)
  501/493    0.004    0.000    3.899    0.008 reactive.py:167(__set__)
  324/316    0.003    0.000    3.859    0.012 reactive.py:201(_check_watchers)
  235/231    0.001    0.000    3.853    0.017 reactive.py:222(invoke_watcher)
      128    0.000    0.000    3.839    0.030 dom.py:1207(_update_styles)
      128    0.001    0.000    3.838    0.030 app.py:1569(update_styles)
      121    0.000    0.000    3.802    0.031 widget.py:2899(watch_has_focus)
   148595    0.145    0.000    3.691    0.000 stylesheet.py:407(_check_rule)
   146496    1.134    0.000    3.565    0.000 match.py:27(_check_selectors)
   905477    0.835    0.000    2.348    0.000 model.py:80(check)
      259    0.001    0.000    2.096    0.008 selectors.py:451(select)
      259    2.094    0.008    2.094    0.008 {method 'poll' of 'select.epoll' objects}
       62    0.001    0.000    1.935    0.031 widget.py:3362(_on_focus)
       59    0.001    0.000    1.894    0.032 widget.py:3368(_on_blur)
   757/15    0.005    0.000    1.530    0.102 <frozen importlib._bootstrap>:978(_find_and_load)
   729/15    0.003    0.000    1.530    0.102 <frozen importlib._bootstrap>:948(_find_and_load_unlocked)
   713/16    0.004    0.000    1.527    0.095 <frozen importlib._bootstrap>:663(_load_unlocked)
   646/15    0.002    0.000    1.527    0.102 <frozen importlib._bootstrap_external>:722(exec_module)
   865/16    0.001    0.000    1.524    0.095 <frozen importlib._bootstrap>:211(_call_with_frames_removed)
       64    0.000    0.000    1.414    0.022 app.py:1424(run_app)
       64    0.000    0.000    1.414    0.022 app.py:1333(run_async)
       47    0.000    0.000    1.408    0.030 app.py:2159(_process_messages)
       47    0.000    0.000    1.370    0.029 app.py:2216(run_process_messages)
      245    0.001    0.000    1.325    0.005 app.py:2674(on_event)
      131    0.001    0.000    1.286    0.010 app.py:2652(check_bindings)
       65    0.000    0.000    1.285    0.020 app.py:2839(_on_key)
       66    0.001    0.000    1.282    0.019 app.py:2725(run_action)
      125    0.001    0.000    1.281    0.010 app.py:2762(_dispatch_action)
       59    0.000    0.000    1.275    0.022 app.py:3123(action_focus_next)
       59    0.000    0.000    1.275    0.022 screen.py:441(focus_next)
       59    0.001    0.000    1.275    0.022 screen.py:377(_move_focus)
       38    0.000    0.000    1.160    0.031 screen.py:630(_compositor_refresh)
       65    0.001    0.000    1.129    0.017 screen.py:554(set_focus)
       29    0.000    0.000    1.118    0.039 _compositor.py:950(render_update)
        2    0.000    0.000    1.113    0.557 disk.py:1(<module>)

[github-actions[bot]]

We found the following entry in the FAQ which you may find helpful:

• How can I select and copy text in a Textual app?

Feel free to close this issue if you found an answer in the FAQ. Otherwise, please give us a little time to review.

This is an automated reply, generated by FAQtory

[willmcgugan]

Whatever performance issues you have, it is unlikely to be explained by the time it takes to invoke an event. Textual runs quite well on a Raspberry Pi.

Without any other context, it is impossible to offer any suggestions. Suggest you share your code, or at the very least explain what you are trying to accomplish...

[Yurii-huang]

Why do you think there is even a problem?

Or, I might be more focused in a different way.

259    2.094    0.008    2.094    0.008 {method 'poll' of 'select.epoll' objects}

Does Textual use the epoll feature? Where is it?

Other good ideas for the code loop that I have will update to the current issue as well.

Thanks

[willmcgugan]

I don't believe there is much, if any, opportunity for optimization of the event system. And even if it were essentially free, they majority of time would be spent rendering the UI, processing CSS etc.

the status quo isn't as good as it could be

How do you know this? It could be entirely optimal. And you haven't presented any evidence to the contrary. But if you have any suggestions, I'm all ears.

select is in the standard library.

[Yurii-huang]

I don't believe there is much, if any, opportunity for optimization of the event system. And even if it were essentially free, they majority of time would be spent rendering the UI, processing CSS etc.

the status quo isn't as good as it could be

How do you know this? It could be entirely optimal. And you haven't presented any evidence to the contrary. But if you have any suggestions, I'm all ears.

select is in the standard library.

I found a problem with focus_next getting all the selectors (looking them up one by one from the DOM) and whether to precede the selector traversal to a direct fetch for sequential component operations (you can make the selector part of the component's additional properties, isn't it).

[Yurii-huang]

I don't believe there is much, if any, opportunity for optimization of the event system. And even if it were essentially free, they majority of time would be spent rendering the UI, processing CSS etc.

the status quo isn't as good as it could be

How do you know this? It could be entirely optimal. And you haven't presented any evidence to the contrary. But if you have any suggestions, I'm all ears.
select is in the standard library.

I found a problem with focus_next getting all the selectors (looking them up one by one from the DOM) and whether to precede the selector traversal to a direct fetch for sequential component operations (you can make the selector part of the component's additional properties, isn't it).

[Yurii-huang]

What I don't understand is what the purpose of this place is to match the selector, which seems to be a redundant judgment condition