Callum Law 7cc718f1c1 LibWeb: Avoid vector creation getting {short,long}hands for CSS property ...

The `shorthands_for_longhand`, `longhands_for_shorthand`, and
`expanded_longhands_for_shorthand` methods can be pretty hot in
profiles where we serialize a lot of CSS properties.

By returning a const reference to a static vector instead of allocating
and returning a new vector every time we can avoid a decent amount of
work.

Overall runtime for the particularly serialization heavy
wpt.live/css/cssom/cssom-getPropertyValue-common-checks.html
decreased by ~20% comparing before and after this change.

2025-07-14 09:08:55 +02:00

64 KiB

Raw Blame History

View Raw