1962895 - Testcase generating compositionevents is 2x slower and takes 20x more RAM compared to Chrome.

Status: NEW

(Core :: DOM: Events, defect)

Description

[Mayank Bansal]

Attachment: Composition Events.HTML

open testcase
N=5000000

Firefox: https://share.firefox.dev/3RxIDXE (10s)
Chrome: https://share.firefox.dev/42H0aTL (4.7s)

Firefox also uses 2.3GB+ RAM, whereas Chrome takes maybe 100MB.

Comment 1

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(sickish, maybe slower respose)]

Well, we have some composition event listeners for handling trusted composition events to support IME in the editor and to provide better UX with autocomplete etc. That might be improved with making the event listeners never listen untrusted events, but looks like that most cost is the basic handling of an event propagation...

Comment 2

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(sickish, maybe slower respose)]

-> S4

I don't think this is so important because untrusted CompositionEvent shouldn't be used in real web apps. Web apps need to handle CompositionEvents synchronously because it's interaction with the system text input system. So, I guess nobody creates CompositionEvent for handling the input asynchronously.

Comment 3

[Mayank Bansal]

5000000
bubble=false: https://share.firefox.dev/4lZEiKU (8.5s)
bubble=false and composed=false: https://share.firefox.dev/3GyjNol (8.5s)
bubble=false and composed=false and cancellable=false: https://share.firefox.dev/42DNahB (8.1s)