Bug 252176

Summary:	[css-nesting] Save memory when we only need old-school StyleRule (=non nested)
Product:	WebKit	Reporter:	Matthieu Dubet <m_dubet>
Component:	WebCore Misc.	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified

Description Matthieu Dubet 2023-02-13 09:28:52 PST

Support for CSS Nesting adds 2 members to the StyleRule class (the resolved selector list, and the list of children rules).

This creates a regression in Membuster benchmark (~2Mb). 

We should have a "happy path" where we don't pay the memory cost of the nesting feature when we don't need it.

Comment 1 Radar WebKit Bug Importer 2023-02-13 09:29:10 PST

<rdar://problem/105399781>

Comment 2 Matthieu Dubet 2023-02-13 10:04:24 PST

Pull request: https://github.com/WebKit/WebKit/pull/10044

Comment 3 EWS 2023-02-14 15:21:13 PST

Committed 260281@main (9db1de406e2b): <https://commits.webkit.org/260281@main>

Reviewed commits have been landed. Closing PR #10044 and removing active labels.