Make background drawing faster, most notably image decoding

[jwijenbergh]

Issue description

Currently background drawing is very slow (obviously depends on the image). The main culprit is the decoding of the wallpaper using cairocffi.pixbuf.decode_to_image_surface. This is really problematic as we have to re-render the wallpaper every time the screen layout changes. On wayland this can even result in short freezes when you disable/enable monitors. Possible approaches:

• cache the image data, maybe not smart if large
• do some sort of async thing with decoding?

ideas?

Version

git

Backend

Wayland (experimental)

Config

No response

Logs

No response

Required

• I have searched past issues to see if this bug has already been reported, and it hasn't been.
• I understand that people give their precious time for free, and thus I've done my very best to make this problem as easy as possible to investigate.

[tych0]

caching it seems reasonable, how big is one of these when they're parsed?

but i wonder: can we just not re-paint the background if it's the same after the screens are reconfigured?

[jwijenbergh]

how big is one of these when they're parsed

sys.getsizeof(image) only returns 56 bytes haha, not sure if that is completely correct

but i wonder: can we just not re-paint the background if it's the same after the screens are reconfigured?

Yeah that is a good point. I could look at this, now we generate a whole new surface/buffer

[elParaguayo]

@tych0 I don't think this is urgent for the next release. If wayland is now working on wlroots 0.17, we should do a release now.

[jwijenbergh]

Yeah it's not, this has always been here

[tych0]

If wayland is now working on wlroots 0.17, we should do a release now.

ok! I will go ahead and start the process :)

[jwijenbergh]

Merci! I merged some last minute fixes, so good to go from my end

[tych0]

https://github.com/qtile/qtile/releases/tag/v0.26.0 everything is grinding away, I will keep an eye on it and make sure it all goes green.

[jwijenbergh]

Green! Woohoo! Thanks