Commands are not debounced

[rakyi]

Would it be possible to add (configurable) debouncing to (some) commands?

I think it would be especially useful for the grep and find commands. High amount of candidates can create noticeable slowdown. Although ripgrep is often fast enough on a modern machine, running it less frequently than necessary should also improve battery usage.

Found a similar issue in ivy: abo-abo/swiper#1218

[minad]

I am already using a timer and I added configuration variables to tune this. Please try it! Maybe some other values for the delays work better for you?

[minad]

@rakyi I just thought about this issue again and I wonder if the current throttling is not sufficient. Debouncing here would mean that we only run grep after the user hasn't typed something for a certain time. Would that be preferable?

[rakyi]

Thanks for the thoughtful consideration! I don't understand emacs and elisp well enough to know what exactly are consult-async-input-delay and consult-async-refresh-delay variables doing. I was scratching my head when I was comparing their default values against slightly higher ones.

Debouncing here would mean that we only run grep after the user hasn't typed something for a certain time.

This is what I had in mind. I don't know if it makes sense to combine the debouncing approach with the existing one or what the majority of users would expect. I'm familiar with debouncing from web development and I think it usually works well in that domain.

[minad]

Tbh I wasn't aware of the distinction of throttling vs debouncing in this context. But I guess it makes kind of sense since I know debouncing from electronics :)

• Throttle: allows restarting grep every 0.5s, triggered by user input
• Refresh: allows refreshing the ui every 0.2s, triggered by incoming strings from the asynchronous background process
• Debounce (not yet implemented): allow restarting grep only if the last keypress is older than a certain time, e.g. 0.2s

[minad]

I implemented additional debouncing. This is really an improvement! Thank you!

[rakyi]

Thanks for adding it! When I tried (setq consult-async-input-throttle 0) I get cancel-timer: Wrong type argument: timerp, nil when I run consult-ripgrep. When I set it to nil instead I don't get any error, but the search is run only once.

Would it be possible to add a way to disable the throttle? I wanted to try relying only on debounce.

[minad]

I am not eager to add support to disable this. It is good to have both debounce and throttle. I don't see how it hurts to have both. Can you explain?

[rakyi]

I was wondering if in the worst case scenario the actual delay wont be 0.5s (or even 0.75s) after the last input when the throttle timer ticks just before the debounce one. Or is the delay always at most the debounce time (0.25s)?

[minad]

The throttle time just ensures that grep is at most restarted every 0.5s. There is also an initial delay of 0.5s, but we could get rid of that if that is desired. But from my tests it seems reasonable like this.

Furthermore there is the debouncer which ensures that an update does not happen earlier than 0.25s after the last keypress.

To make it clear, current initial total delay is 0.5s.

[minad]

It might also be sufficient to only have the debouncer. This is what you are suggesting. But I think in some scenarios setting a large throttle value (let's say 2s) and a small debounce value makes sense. The different delays serve different purposes. The debouncer ensures that you are not sending unfinished input. And the throttler ensures that you limit the load.