RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-06-01 08:38:10 +00:00
Code Issues Activity Actions

LibWeb: Cache the root element font metrics when calculating them

Browse source 
The root element font metrics were getting queried again and again
during style computation. Before this change we would do some work to
recalculate them each time.

This patch simply caches them in a StyleComputer member. Since style
updates always start with the root element, we know that it'll be
up-to-date by the time we look at any other element.

Before this change, we were spending ~5% of CPU time on Google Groups
in root_element_font_metrics().
This commit is contained in:
Andreas Kling 2023-05-08 10:28:21 +02:00
parent 214eaebe73
commit 3f4de06fc2
2 changed files with 26 additions and 33 deletions
Download patch file Download diff file Expand all files Collapse all files

5
Userland/Libraries/LibWeb/CSS/StyleComputer.h
View file

@ -102,7 +102,7 @@ private:
void for_each_stylesheet(CascadeOrigin, Callback) const;
CSSPixelRect viewport_rect() const;
Length::FontMetrics root_element_font_metrics() const;
[[nodiscard]] Length::FontMetrics calculate_root_element_font_metrics(StyleProperties const&) const;
CSSPixels parent_or_root_element_line_height(DOM::Element const*, Optional<CSS::Selector::PseudoElement>) const;
struct MatchingRuleSet {
@ -133,6 +133,9 @@ private:
class FontLoader;
HashMap<String, NonnullOwnPtr<FontLoader>> m_loaded_fonts;
Length::FontMetrics m_default_font_metrics;
Length::FontMetrics m_root_element_font_metrics;
};
}