Console rendering very slow with respect to process execution about terminus

[PaulBGD]

I don't know if it's because of Windows, but rendering is very slow. Switched to just using an external terminal now.

[randy3k]

It is unfortunate something hard to optimize. If you figure out something, please let me know.

[brupelo]

Sure thing, I'll need to get familiar first with terminus as a user (only 20 minutes of usage so far ;)) and then I'll start getting familiar as a dev so eventually I'll be able to give it a proper shot to this one, so please keep it open in the meantime.

Actually, I've also got a similar problem with some code of mine that start threads to spawn processes and then write to views, the difference between process execution & rendering is also quite big. In my case I think the bottleneck is the number of calls I do to self.view.run_command('append', { 'characters': characters, 'force': True, 'scroll_to_end': True}) is very big while reading from the process so one thing I've thought in my case was minimizing as hard as possible the number of those calls.

Haven't looked yet to terminus code so not sure which method uses to render process stdout/stderr (ie: I'll need to profile it to find the hotspots).

[randy3k]

It seems that the bottleneck is the reader of the process tty.

we might how to run the command self.view.window() and view_is_attached less often as they can be slow.

[lapega]

In Ubuntu 18.04 there's a little delay when pressing keys. The usage feels very slow compared to gnome terminal or tilix.
Anyway, great plugin!

[randy3k]

I measured the delay of typing a key and it is about 0.03-0.04s on my computer, which is barely noticeable. Did you installed a package which may be possible conflicting with Terminus?

[lapega]

I have a lot of packages installed, maybe we can cross data with @brupelo

• ColorPicker
• Emmet Css Snippets
• HTML
• jsonschema
• PHP
• PHP_CodeSniffer
• php-completions
• php-grammar
• php-snippets
• ptyprocess
• pyte
• python-jinja2
• PyV8
• Rails
• SublimeCodeIntel
• Terminus
• wcwidth
• zzz A File Icon zzz

[randy3k]

what you are experiencing is different from @brupelo . OP's issue is about rendering of huge output, not about delay in typing a key (though they could be related). It is known that Terminus doesn’t render huge output well.

[landoncope]

I've found that commenting out the self.view.window() line in terminal.py (line 100) speeds things up significantly, though the window is less responsive during the outputting.

[randy3k]

by speeding up, do you mean the rendering time or the delay between typing keys?

[landoncope]

@randy3k: rendering time

[landoncope]

I fiddled with it for a while to come up with a fast solution that was also responsive (during massive output), but I didn't come up with anything. Now that I think about it more, something simple like only allowing that self.view.window() line to be called every 100ms, but allowing the rest of the loop to run at speed, would probably do the trick.

[randy3k]

I have just pushed a commit 158934b which makes rendering more responsive (unfortunately slower). It also removes the use of the dirty code self.view.window() which may allow us to further optimize the speed.

With that said, being responsive is actually more important here: a user can still interrupt the process with ctrl+c although the rendering is slow.

[landoncope]

@randy3k - I'm using your new code, and it now feels fast enough to me (compared to the original code) with massive output, and responsive as well. I'm running on MacOS.

[randy3k]

@lapega

Just a heads up. I forgot to ask you whether you turned on the debug mode. Obviously, with the debug mode one, the rendering would become much slower.