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Array clone on DispatchEvent

See original GitHub issue

I just noticed that in the DispatchEvent function from the EventDispatcher the listeners array is cloned on every call https://github.com/mrdoob/three.js/blob/dev/src/core/EventDispatcher.js#L71. That doesn’t look like nice for the GC. Is there any specific reason that I may be missing why this is working that way instead of just removing that line and iterate directly on listenerArray? /cc @mrdoob

Issue Analytics

State:
Created 4 years ago
Comments:5 (2 by maintainers)

Top GitHub Comments

1reaction

gkjohnsoncommented, May 9, 2019

It could be possible for one of the callbacks to remove any of the other ones, right? Not just itself? So no matter what order you traverse the callbacks in you’ll wind up changing the behavior of the class in some cases if you don’t clone the array.

1reaction

fernandojsgcommented, May 9, 2019

That makes sense yep, what about using unshift instead of push? That will make the order correct even if iterating back-to-front https://jsfiddle.net/8nwqaept/

I guess it could be nice to benchmark unshift performance impact versus slice()+push 😄

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