Hyper Canary - Slow stream from running programs

[richrace]

Setup:

Issue: Visible slow down with streaming output from command or log files.

Test:

for ((i=1; i<=10000; i++)); do
   echo $i
done

[hharnisc]

Hey @richrace :wave:

Thank you for the report here, this one has been an issue for quite some time - this snippet is great for reproduce the issue (was using the yes command which would always cause it to hang :smile: ). Unfortunately with the current implementation of Hyper, we have to check the process (almost) every time the output changes on the console. So the trade off is efficiency vs usefulness. -- I need to double check what's different in the 2.X canary release, if that changed we might be able to fix this!

[rauchg]

Just ran into this as well. yes in Hyper canary is nearly native-like, but if I turn on hypercwd, it barely renders.

I have an idea for a new strategy: only obtain the cwd upon creating a new tab or window. Don't do anything when the terminal is rendering.

[Esteban-Rocha]

Same here got to deactivate until this is fixed

[hharnisc]

Grabbed some performance data from chrome dev tools. Comparing the performance of the following script (basically the same as what you shared @richrace) on Hyper 2.0.0-canary.14:

for i in `seq 1 10000`;
do
  echo $i
done

Note: these comparisons are done while collecting performance metrics so the values don't reflect the actual performance -- the difference in performance under the same conditions is what is important here.

Without hypercwd:

Render Time: ~359.8ms Min FPS: ~5

With hypercwd:

Render Time: ~60 Seconds (yes seconds!) Min FPS: 0

It's clear in this view how expensive the spawn is -- and much more of an issue when streaming logs etc.

It's much more clear what's happening under the hood -- and I've got a couple ideas on how to fix this. Thank you for the input everyone :raised_hands:

[hharnisc]

I implemented an edge trigger function -- think debounce, but runs the passed in function at beginning and the end. And got pretty much the same performance as hyper without the plug ins. I'll deploy this soon! cc/ @rauchg

Render Time: ~428.1ms Min FPS: ~4

This fix should dramatically improve performance on OS X + Windows

[hharnisc]

Just published 1.2.1 release if you'd like to give this a try @rauchg @richrace @Esteban-Rocha

[richrace]

Brilliant. That works a treat 👍. Thanks!

I've patch my local copy of https://github.com/henrikdahl/hyper-statusline with your changes and it fixes https://github.com/henrikdahl/hyper-statusline/issues/69 too!

[bmrobin]

I've patch my local copy of https://github.com/henrikdahl/hyper-statusline with your changes and it fixes henrikdahl/hyper-statusline#69 too!

@richrace would you mind submitting a PR with that change to the hyper-statusline repository? i don't see any activity there related to fixing this issue and if you already have @hharnisc 's solution implemented then we could get that merged into the other project as well.

[Exomnius]

@richrace is it possible that you share your fix for https://github.com/henrikdahl/hyper-statusline too?

[j-f1]

@richrace If you open a PR on my fork, I’ll get it released to npm.

[richrace]

@j-f1 Hey, Sorry, but I don't use HyperJS anymore. And the "fix" I used didn't really solve it.

For example, the CWD in the status line would not update correctly and then be completely out of sync.