Performance issues using imports vs single .slint file about slint HOT 6 CLOSED

Ok great. I plan on having quite a large global state (not of images, but of just more primitive types). So I will have to have a play around and see how it scales with large models. Hopefully well, as I'm otherwise excited by this framework.

Thanks again for your time.

from slint.

I can reproduce this and I see what the cause for this is:

Each image is 1140x1600 pixels, taking up ~5.4MB RAM after decoding. The built-in image cache in Slint is 5 MB (decoded images). So the images don't fit into the cache and are reloaded every time, which takes up time.

We could try to change the heuristics or defaults for the cache, but I think the best for your situation would be to be 100% in control here. That's probably best achieved by loading the images yourself with load_from_path in Rust and pass them into Slint for use.

from slint.

remove the lag is to either remove the imports and put all the Slint code in a single file.

This part points towards a bug in our inlining / const propagation. If the model binding expression that includes the @image-url is inlined, then this becomes a lot more expensive as Things is re-created and thus this is re-evaluated. If it's not inlined, then the ModelRc is re-used and cloned.

from slint.

We discussed a bit further on the inlining, but usually @image-url is fast - so that might not be the right kind of de-optimization.

My suggestion remains that if you have images so big, it's best to not load them with @image-url but with load_from_path and keep them alive that way.

from slint.

@tronical I appreciate your time and the detailed response. I will have a play with moving those images elsewhere.

My assumption was the global/singleton stuff was like something I could use as a global state and propagate changes out to my application. Though if it's being reloaded/reinstantiated, then that's probably not how I should use it.

from slint.

Your assumption are quite sensible - I think it’s a good approach. You just happen to become a “victim” of the image cache:). If there was no cache at all, then it would be more obvious that the user needs to take care of that. But the cache helps in many cases - just not this one :)

from slint.