1999301 - www.arthurvasseur.fr - Freezes/Stutters slightly when scrolling the page due to large data:-URL in faviconUrl in tabs.onUpdated

Status: NEW

(WebExtensions :: General, defect, P3)

Description

[Calin Tanase (PTO until 15th of May)]

Environment:
Operating system: Windows 10
Firefox version: Firefox 145.0/144/146

Steps to reproduce:

1. Go to https://www.arthurvasseur.fr/blog/vkd-memory-management/
2. Scroll the page normally/fast (using the mouse wheel).

Expected Behavior:
The scrolling is smooth.

Actual Behavior:
It lags slightly.

Notes:

• Reproduces regardless of the status of ETP
• Reproduces in firefox-nightly, and firefox-release
• Does not reproduce in chrome

Created from https://github.com/webcompat/web-bugs/issues/187577

Comment 1

[Calin Tanase (PTO until 15th of May)]

Attachment: arthurvasseur.fr scroll Nightly vs Chrome.mp4

Comment 2

[Dennis Schubert [:denschub]]

Profile: https://share.firefox.dev/4nPvtTq

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:bas.schouten, could you have a look please?

For more information, please visit BugBot documentation.

Comment 4

[Markus Stange [:mstange]]

The page has a 10MB favicon (https://www.arthurvasseur.fr/favicon.svg) and it updates the history state during scrolling. The freezes happen when the parent process sends a tabs.onUpdated message to the WebExtension process.

For some reason, the faviconUrl property in the message contains a data URL with the base64-encoded icon. This makes the message huge (13.8MB), see this size profile: https://share.firefox.dev/4rMU4vB

Why aren't we using the original favicon URL here, i.e. the string "https://www.arthurvasseur.fr/favicon.svg"?

Comment 5

[Bas Schouten (:bas.schouten)]

The Performance Impact Calculator has determined this bug's performance impact to be medium. If you'd like to request re-triage, you can reset the Performance Impact flag to "?" or needinfo the triage sheriff.

Platforms: [x] Windows [x] macOS [x] Linux
Impact on browser: Causes noticeable jank
Configuration: Specific but common

Comment 6

[Rob Wu [:robwu]]

It would be really nice if we move away from data:-URLs as faviconUrl. This has been an ongoing source of performance issues.

Bug 1315616 asks about a way to access cached favicons. That should be the preferred fix here.

I don't know why faviconUrl here is the data:-URL instead of the original URL. Fixing that could also be a path towards a fix.

Another potential fix is to simply drop faviconUrl from events by default if their length exceeds a certain length, as a stopgap fix for this issue.

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:rpl, could you have a look please?

For more information, please visit BugBot documentation.