Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-08-03 04:30:10 +01:00
Code Issues Projects Releases Packages Wiki Activity

Make note_selector more efficient.

Browse source 
My measurements are inconclusive as to whether this really moves the
needle, but it seems like the right way to do it in any case.

MozReview-Commit-ID: 7OuCc2aQ7jH
This commit is contained in:
Bobby Holley 2017-04-27 18:09:06 -07:00
parent b4a2e2f17c
commit a6ef89a7fe
1 changed files with 43 additions and 36 deletions
Download patch file Download diff file Expand all files Collapse all files

79
components/style/restyle_hints.rs
View file

@ -525,56 +525,63 @@ impl DependencySet {
/// Adds a selector to this `DependencySet`.
pub fn note_selector(&mut self, selector: &Selector<SelectorImpl>) {
let mut is_pseudo_element = selector.pseudo_element.is_some();
let mut next = Some(selector.inner.complex.clone());
let mut combinator = None;
let mut iter = selector.inner.complex.iter();
let mut index = 0;
while let Some(current) = next.take() {
// Set up our visitor.
loop {
let sequence_start = index;
let mut visitor = SensitivitiesVisitor {
sensitivities: Sensitivities::new()
};
let mut hint = combinator_to_restyle_hint(combinator);
if is_pseudo_element {
// TODO(emilio): use more fancy restyle hints to avoid restyling
// the whole subtree when pseudos change.
//
// We currently need is_pseudo_element to handle eager pseudos
// (so the style the parent stores doesn't become stale), and
// restyle_descendants to handle all of them (::before and
// ::after, because we find them in the subtree, and other lazy
// pseudos for the same reason).
hint |= RESTYLE_SELF | RESTYLE_DESCENDANTS;
is_pseudo_element = false;
// Visit all the simple selectors in this sequence.
//
// Note that this works because we can't have combinators nested
// inside simple selectors (i.e. in :not() or :-moz-any()). If we
// ever support that we'll need to visit complex selectors as well.
for ss in &mut iter {
ss.visit(&mut visitor);
index += 1; // Account for the simple selector.
}
{
// Visit all the simple selectors.
let mut iter = current.iter();
let mut index = 0usize;
for ss in &mut iter {
ss.visit(&mut visitor);
index += 1;
}
// Prepare the next sequence of simple selectors.
if let Some(next_combinator) = iter.next_sequence() {
next = Some(current.slice_from(index + 1));
combinator = Some(next_combinator);
}
}
// Note what we found.
// If we found a sensitivity, add an entry in the dependency set.
if !visitor.sensitivities.is_empty() {
let mut hint = combinator_to_restyle_hint(combinator);
let dep_selector;
if sequence_start == 0 {
if selector.pseudo_element.is_some() {
// TODO(emilio): use more fancy restyle hints to avoid
// restyling the whole subtree when pseudos change.
//
// We currently need is_pseudo_element to handle eager
// pseudos (so the style the parent stores doesn't
// become stale), and restyle_descendants to handle all
// of them (::before and ::after, because we find them
// in the subtree, and other lazy pseudos for the same
// reason).
hint |= RESTYLE_SELF | RESTYLE_DESCENDANTS;
}
// Reuse the bloom hashes if this is the base selector.
dep_selector = selector.inner.clone();
} else {
dep_selector = SelectorInner::new(selector.inner.complex.slice_from(sequence_start));
}
self.add_dependency(Dependency {
sensitivities: visitor.sensitivities,
hint: hint,
selector: SelectorInner::new(current),
})
selector: dep_selector,
});
}
combinator = iter.next_sequence();
if combinator.is_none() {
break;
}
index += 1; // Account for the combinator.
}
}