haskell-language-server is chatty about progress

[mitchellwrosen]

Is your enhancement request related to a problem? Please describe.

haskell-language-server seems rather chatty with its progress updates. In particular, after the initial long load, while I'm actively editing a buffer, the server sends a huge number of very short-lived progress updates (where the "end" notification occurs a fraction of a second after the "begin" notification) that just say the word "Processing".

Describe the solution you'd like

I'm not exactly sure - on one hand, I should think that a language-server would always be in the background "processing" things, so perhaps these notifications simply shouldn't be emitted at all. Alternatively, they could be made more informative.

Thanks!

[michaelpj]

Generally our progress notifications are pretty bad, I'm not sure what to do about that.

I suspect what's going on here is that we're sending progress for every module we're loading or similar. That's not a crazy thing to do, but it's perhaps unnecessary, and it would be good if the notification actually said something useful, like what the module was.

[Anrock]

Personally I like current progress reports. I don't know if sending lots of short-lived notifications have any detrimental effect but seeing 140/180 modules message is pretty neat in my neovim. It also gives a hint that I should split my modules further when after changing a single definition it reprocesses 40 other modules :sweat_smile:

[mitchellwrosen]

@Anrock Please note this issue is not about progress notifications in general. I also like seeing messages like "X/Y modules", especially when Y is large or getting to Y/Y takes more than a couple seconds.

However, as mentioned in the issue description there are notifications that literally just say the word "Processing" and no more.

I think whether or not there are detrimental effects of sending many notifications is mostly a function of client settings. I recently toyed around with a fancier graphical notification plugin, which is what drew my attention to hls; I'm sure you can imagine what getting a hundred toasts a minute while editing text would be like. But if you just have notifications drawn on a single line somewhere, and each notification just overwrites whatever is there, then I'm not sure it matters much either way ;)

[July541]

You can only see Processing from hls is here, should the text be optimized?

https://github.com/haskell/haskell-language-server/blob/41cd52e603ab4e1c7d8fcbf95140610c2a1fe04e/ghcide/src/Development/IDE/Core/ProgressReporting.hs#L137-L146

[michaelpj]

We can also tweak the frequency of the progress reports here: https://github.com/haskell/haskell-language-server/blob/master/ghcide/src/Development/IDE/Core/Shake.hs#LL635C72-L635C72

[mortezadadgar]

any progress on this?

[michaelpj]

I think this is hopefully fixed or at least better UX: we now have a universal delay on starting progress, so we won't show it for short-lived operations; and then updates are throttled.