createBroadcast implementation causes performance issues

this lines

return () => {
    listeners = listeners.filter(item => item !== listener)
 }

produce a lot of new objects which leads to a frequent garbage collections, which take sometimes up to 250 ms.

this can be probably avoided by changing listeners from array to a simple hash object like { [id]: listner }, and the lines above to

return () => {
    delete listeners[id]
 }

[vesparny]

I have published a new version of brcast that addresses this issue. Feel free to steal the code from there while you wait to switch to theming

[kitten]

We should probably just switch to iamstarkov/theming soon.

But it depends on brcast which uses the same filtering logic unfortunately: https://github.com/vesparny/brcast/blob/master/index.js#L16