servo/components/script/dom/cssfontfacerule.rs
JoeDow 6e6ef513a9
Reuse StylesheetContent for inline style sheets with identical content (#38540)
For duplicate style sheets with identical content, `StylesheetContents`
can be reused to avoid redundant parsing of the inline style sheets.
Since duplicate stylesheets is a common case with web components, this
change will significantly improve performance. Additionally, the cache
hit rate of stylo's `CascadeDataCache` can now be significantly
improved.

When shared `StylesheetContents` is modified, copy-on-write will occur
to avoid affecting other sharers. And then updates the references to
`CssRule` or `PropertyDeclarationBlock` stored in the CSSOMs to ensure
that modifications are made only on the new copy.

Signed-off-by: sharpshooter_pt <ibluegalaxy_taoj@163.com>
2025-08-20 12:31:49 +00:00

74 lines
2.1 KiB
Rust

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
use std::cell::RefCell;
use dom_struct::dom_struct;
use servo_arc::Arc;
use style::shared_lock::{Locked, ToCssWithGuard};
use style::stylesheets::{CssRuleType, FontFaceRule};
use crate::dom::bindings::reflector::reflect_dom_object;
use crate::dom::bindings::root::DomRoot;
use crate::dom::bindings::str::DOMString;
use crate::dom::cssrule::{CSSRule, SpecificCSSRule};
use crate::dom::cssstylesheet::CSSStyleSheet;
use crate::dom::window::Window;
use crate::script_runtime::CanGc;
#[dom_struct]
pub(crate) struct CSSFontFaceRule {
cssrule: CSSRule,
#[ignore_malloc_size_of = "Arc"]
#[no_trace]
fontfacerule: RefCell<Arc<Locked<FontFaceRule>>>,
}
impl CSSFontFaceRule {
fn new_inherited(
parent_stylesheet: &CSSStyleSheet,
fontfacerule: Arc<Locked<FontFaceRule>>,
) -> CSSFontFaceRule {
CSSFontFaceRule {
cssrule: CSSRule::new_inherited(parent_stylesheet),
fontfacerule: RefCell::new(fontfacerule),
}
}
#[cfg_attr(crown, allow(crown::unrooted_must_root))]
pub(crate) fn new(
window: &Window,
parent_stylesheet: &CSSStyleSheet,
fontfacerule: Arc<Locked<FontFaceRule>>,
can_gc: CanGc,
) -> DomRoot<CSSFontFaceRule> {
reflect_dom_object(
Box::new(CSSFontFaceRule::new_inherited(
parent_stylesheet,
fontfacerule,
)),
window,
can_gc,
)
}
pub(crate) fn update_rule(&self, fontfacerule: Arc<Locked<FontFaceRule>>) {
*self.fontfacerule.borrow_mut() = fontfacerule;
}
}
impl SpecificCSSRule for CSSFontFaceRule {
fn ty(&self) -> CssRuleType {
CssRuleType::FontFace
}
fn get_css(&self) -> DOMString {
let guard = self.cssrule.shared_lock().read();
self.fontfacerule
.borrow()
.read_with(&guard)
.to_css_string(&guard)
.into()
}
}