style: Record ElementState bits that selectors depend on.

This commit is contained in:
Cameron McCormack 2017-05-09 18:07:40 +08:00
parent 5cf915118e
commit b405a1cb67
2 changed files with 36 additions and 6 deletions

View file

@ -11,6 +11,7 @@ use bit_vec::BitVec;
use context::QuirksMode;
use data::ComputedStyle;
use dom::{AnimationRules, TElement};
use element_state::ElementState;
use error_reporting::RustLogReporter;
use font_metrics::FontMetricsProvider;
use keyframes::KeyframesAnimation;
@ -135,6 +136,11 @@ pub struct Stylist {
/// returning `true` for `"style"` just due to a hash collision.)
style_attribute_dependency: bool,
/// The element state bits that are relied on by selectors. Like
/// `attribute_dependencies`, this is used to avoid taking element snapshots
/// when an irrelevant element state bit changes.
state_dependencies: ElementState,
/// Selectors that require explicit cache revalidation (i.e. which depend
/// on state that is not otherwise visible to the cache, like attributes or
/// tree-structural state like child index and pseudos).
@ -203,6 +209,7 @@ impl Stylist {
dependencies: DependencySet::new(),
attribute_dependencies: BloomFilter::new(),
style_attribute_dependency: false,
state_dependencies: ElementState::empty(),
selectors_for_cache_revalidation: SelectorMap::new(),
num_selectors: 0,
num_declarations: 0,
@ -275,6 +282,7 @@ impl Stylist {
self.dependencies.clear();
self.attribute_dependencies.clear();
self.style_attribute_dependency = false;
self.state_dependencies = ElementState::empty();
self.selectors_for_cache_revalidation = SelectorMap::new();
self.num_selectors = 0;
self.num_declarations = 0;
@ -396,7 +404,7 @@ impl Stylist {
self.add_rule_to_map(selector, locked, stylesheet);
self.dependencies.note_selector(selector);
self.note_for_revalidation(selector);
self.note_attribute_dependencies(selector);
self.note_attribute_and_state_dependencies(selector);
}
self.rules_source_order += 1;
}
@ -473,9 +481,15 @@ impl Stylist {
}
}
/// Returns whether the given ElementState bit is relied upon by a selector
/// of some rule in the stylist.
pub fn has_state_dependency(&self, state: ElementState) -> bool {
self.state_dependencies.intersects(state)
}
#[inline]
fn note_attribute_dependencies(&mut self, selector: &Selector<SelectorImpl>) {
selector.visit(&mut AttributeDependencyVisitor(self));
fn note_attribute_and_state_dependencies(&mut self, selector: &Selector<SelectorImpl>) {
selector.visit(&mut AttributeAndStateDependencyVisitor(self));
}
/// Computes the style for a given "precomputed" pseudo-element, taking the
@ -1006,10 +1020,11 @@ impl Drop for Stylist {
}
}
/// Visitor to collect names that appear in attribute selectors.
struct AttributeDependencyVisitor<'a>(&'a mut Stylist);
/// Visitor to collect names that appear in attribute selectors and any
/// dependencies on ElementState bits.
struct AttributeAndStateDependencyVisitor<'a>(&'a mut Stylist);
impl<'a> SelectorVisitor for AttributeDependencyVisitor<'a> {
impl<'a> SelectorVisitor for AttributeAndStateDependencyVisitor<'a> {
type Impl = SelectorImpl;
fn visit_attribute_selector(&mut self, selector: &AttrSelector<Self::Impl>) -> bool {
@ -1026,6 +1041,13 @@ impl<'a> SelectorVisitor for AttributeDependencyVisitor<'a> {
}
true
}
fn visit_simple_selector(&mut self, s: &Component<SelectorImpl>) -> bool {
if let Component::NonTSPseudoClass(ref p) = *s {
self.0.state_dependencies.insert(p.state_flag());
}
true
}
}
/// Visitor determine whether a selector requires cache revalidation.

View file

@ -17,6 +17,7 @@ use style::context::{ThreadLocalStyleContext, ThreadLocalStyleContextCreationInf
use style::data::{ElementData, ElementStyles, RestyleData};
use style::dom::{AnimationOnlyDirtyDescendants, DirtyDescendants};
use style::dom::{ShowSubtreeData, TElement, TNode};
use style::element_state::ElementState;
use style::error_reporting::RustLogReporter;
use style::font_metrics::get_metrics_provider_for_product;
use style::gecko::data::{PerDocumentStyleData, PerDocumentStyleDataImpl};
@ -2338,3 +2339,10 @@ pub extern "C" fn Servo_StyleSet_MightHaveAttributeDependency(raw_data: RawServo
let data = PerDocumentStyleData::from_ffi(raw_data).borrow();
unsafe { Atom::with(local_name, &mut |atom| data.stylist.might_have_attribute_dependency(atom)) }
}
#[no_mangle]
pub extern "C" fn Servo_StyleSet_HasStateDependency(raw_data: RawServoStyleSetBorrowed,
state: u64) -> bool {
let data = PerDocumentStyleData::from_ffi(raw_data).borrow();
data.stylist.has_state_dependency(ElementState::from_bits_truncate(state))
}