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style: Split the invalidation collection from the invalidator step.

Browse source 
This is the first step in reusing the invalidation machinery for other stuff,
potentially including QuerySelector / QuerySelectorAll.
This commit is contained in:
Emilio Cobos Álvarez 2017-10-12 13:32:40 +02:00
parent ec00c660f0
commit b9b3e592dd
No known key found for this signature in database
GPG key ID: 056B727BB9C1027C
4 changed files with 462 additions and 384 deletions
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4
components/style/data.rs
View file

@ -244,6 +244,7 @@ impl ElementData {
return InvalidationResult::empty();
}
use invalidation::element::collector::StateAndAttrInvalidationCollector;
use invalidation::element::invalidator::TreeStyleInvalidator;
debug!("invalidate_style_if_needed: {:?}, flags: {:?}, has_snapshot: {}, \
@ -266,7 +267,8 @@ impl ElementData {
nth_index_cache,
);
let result = invalidator.invalidate();
let result =
invalidator.invalidate::<StateAndAttrInvalidationCollector>();
unsafe { element.set_handled_snapshot() }
debug_assert!(element.handled_snapshot());
result

418
components/style/invalidation/element/collector.rs Normal file
View file

@ -0,0 +1,418 @@
/* 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 http://mozilla.org/MPL/2.0/. */
//! A collector for invalidations due to state and attribute changes.
use Atom;
use context::{QuirksMode, SharedStyleContext};
use data::ElementData;
use dom::TElement;
use element_state::{ElementState, IN_VISITED_OR_UNVISITED_STATE};
use invalidation::element::element_wrapper::{ElementSnapshot, ElementWrapper};
use invalidation::element::invalidation_map::*;
use invalidation::element::invalidator::{InvalidationVector, Invalidation, InvalidationCollector};
use invalidation::element::restyle_hints::*;
use selector_map::SelectorMap;
use selector_parser::Snapshot;
use selectors::NthIndexCache;
use selectors::attr::CaseSensitivity;
use selectors::matching::{MatchingContext, MatchingMode, VisitedHandlingMode};
use selectors::matching::matches_selector;
use smallvec::SmallVec;
#[derive(Debug, PartialEq)]
enum VisitedDependent {
Yes,
No,
}
/// The collector implementation.
struct Collector<'a, 'b: 'a, E>
where
E: TElement,
{
element: E,
wrapper: ElementWrapper<'b, E>,
nth_index_cache: Option<&'a mut NthIndexCache>,
snapshot: &'a Snapshot,
quirks_mode: QuirksMode,
lookup_element: E,
removed_id: Option<&'a Atom>,
added_id: Option<&'a Atom>,
classes_removed: &'a SmallVec<[Atom; 8]>,
classes_added: &'a SmallVec<[Atom; 8]>,
state_changes: ElementState,
descendant_invalidations: &'a mut InvalidationVector,
sibling_invalidations: &'a mut InvalidationVector,
invalidates_self: bool,
}
/// A collector for state and attribute invalidations.
pub struct StateAndAttrInvalidationCollector;
impl InvalidationCollector for StateAndAttrInvalidationCollector {
fn collect_invalidations<E>(
element: E,
mut data: Option<&mut ElementData>,
nth_index_cache: Option<&mut NthIndexCache>,
shared_context: &SharedStyleContext,
descendant_invalidations: &mut InvalidationVector,
sibling_invalidations: &mut InvalidationVector,
) -> bool
where
E: TElement,
{
debug_assert!(element.has_snapshot(), "Why bothering?");
debug_assert!(data.is_some(), "How exactly?");
let wrapper =
ElementWrapper::new(element, &*shared_context.snapshot_map);
let state_changes = wrapper.state_changes();
let snapshot = wrapper.snapshot().expect("has_snapshot lied");
if !snapshot.has_attrs() && state_changes.is_empty() {
return false;
}
// If we are sensitive to visitedness and the visited state changed, we
// force a restyle here. Matching doesn't depend on the actual visited
// state at all, so we can't look at matching results to decide what to
// do for this case.
if state_changes.intersects(IN_VISITED_OR_UNVISITED_STATE) {
trace!(" > visitedness change, force subtree restyle");
// We can't just return here because there may also be attribute
// changes as well that imply additional hints.
let data = data.as_mut().unwrap();
data.hint.insert(RestyleHint::restyle_subtree());
}
let mut classes_removed = SmallVec::<[Atom; 8]>::new();
let mut classes_added = SmallVec::<[Atom; 8]>::new();
if snapshot.class_changed() {
// TODO(emilio): Do this more efficiently!
snapshot.each_class(|c| {
if !element.has_class(c, CaseSensitivity::CaseSensitive) {
classes_removed.push(c.clone())
}
});
element.each_class(|c| {
if !snapshot.has_class(c, CaseSensitivity::CaseSensitive) {
classes_added.push(c.clone())
}
})
}
let mut id_removed = None;
let mut id_added = None;
if snapshot.id_changed() {
let old_id = snapshot.id_attr();
let current_id = element.get_id();
if old_id != current_id {
id_removed = old_id;
id_added = current_id;
}
}
let lookup_element =
if element.implemented_pseudo_element().is_some() {
element.pseudo_element_originating_element().unwrap()
} else {
element
};
let invalidated_self = {
let mut collector = Collector {
wrapper,
lookup_element,
nth_index_cache,
state_changes,
element,
snapshot: &snapshot,
quirks_mode: shared_context.quirks_mode(),
removed_id: id_removed.as_ref(),
added_id: id_added.as_ref(),
classes_removed: &classes_removed,
classes_added: &classes_added,
descendant_invalidations,
sibling_invalidations,
invalidates_self: false,
};
shared_context.stylist.each_invalidation_map(|invalidation_map| {
collector.collect_dependencies_in_invalidation_map(invalidation_map);
});
// TODO(emilio): Consider storing dependencies from the UA sheet in
// a different map. If we do that, we can skip the stuff on the
// shared stylist iff cut_off_inheritance is true, and we can look
// just at that map.
let _cut_off_inheritance =
element.each_xbl_stylist(|stylist| {
// FIXME(emilio): Replace with assert / remove when we
// figure out what to do with the quirks mode mismatches
// (that is, when bug 1406875 is properly fixed).
collector.quirks_mode = stylist.quirks_mode();
stylist.each_invalidation_map(|invalidation_map| {
collector.collect_dependencies_in_invalidation_map(invalidation_map);
});
});
collector.invalidates_self
};
if invalidated_self {
if let Some(ref mut data) = data {
data.hint.insert(RESTYLE_SELF);
}
}
invalidated_self
}
}
impl<'a, 'b, E> Collector<'a, 'b, E>
where
E: TElement,
{
fn collect_dependencies_in_invalidation_map(
&mut self,
map: &InvalidationMap,
) {
let quirks_mode = self.quirks_mode;
let removed_id = self.removed_id;
if let Some(ref id) = removed_id {
if let Some(deps) = map.id_to_selector.get(id, quirks_mode) {
for dep in deps {
self.scan_dependency(dep, VisitedDependent::No);
}
}
}
let added_id = self.added_id;
if let Some(ref id) = added_id {
if let Some(deps) = map.id_to_selector.get(id, quirks_mode) {
for dep in deps {
self.scan_dependency(dep, VisitedDependent::No);
}
}
}
for class in self.classes_added.iter().chain(self.classes_removed.iter()) {
if let Some(deps) = map.class_to_selector.get(class, quirks_mode) {
for dep in deps {
self.scan_dependency(dep, VisitedDependent::No);
}
}
}
let should_examine_attribute_selector_map =
self.snapshot.other_attr_changed() ||
(self.snapshot.class_changed() && map.has_class_attribute_selectors) ||
(self.snapshot.id_changed() && map.has_id_attribute_selectors);
if should_examine_attribute_selector_map {
self.collect_dependencies_in_map(
&map.other_attribute_affecting_selectors
)
}
let state_changes = self.state_changes;
if !state_changes.is_empty() {
self.collect_state_dependencies(
&map.state_affecting_selectors,
state_changes,
)
}
}
fn collect_dependencies_in_map(
&mut self,
map: &SelectorMap<Dependency>,
) {
map.lookup_with_additional(
self.lookup_element,
self.quirks_mode,
self.removed_id,
self.classes_removed,
&mut |dependency| {
self.scan_dependency(dependency, VisitedDependent::No);
true
},
);
}
fn collect_state_dependencies(
&mut self,
map: &SelectorMap<StateDependency>,
state_changes: ElementState,
) {
map.lookup_with_additional(
self.lookup_element,
self.quirks_mode,
self.removed_id,
self.classes_removed,
&mut |dependency| {
if !dependency.state.intersects(state_changes) {
return true;
}
let visited_dependent =
if dependency.state.intersects(IN_VISITED_OR_UNVISITED_STATE) {
VisitedDependent::Yes
} else {
VisitedDependent::No
};
self.scan_dependency(&dependency.dep, visited_dependent);
true
},
);
}
/// Check whether a dependency should be taken into account, using a given
/// visited handling mode.
fn check_dependency(
&mut self,
visited_handling_mode: VisitedHandlingMode,
dependency: &Dependency,
relevant_link_found: &mut bool,
) -> bool {
let (matches_now, relevant_link_found_now) = {
let mut context = MatchingContext::new_for_visited(
MatchingMode::Normal,
None,
self.nth_index_cache.as_mut().map(|c| &mut **c),
visited_handling_mode,
self.quirks_mode,
);
let matches_now = matches_selector(
&dependency.selector,
dependency.selector_offset,
None,
&self.element,
&mut context,
&mut |_, _| {},
);
(matches_now, context.relevant_link_found)
};
let (matched_then, relevant_link_found_then) = {
let mut context = MatchingContext::new_for_visited(
MatchingMode::Normal,
None,
self.nth_index_cache.as_mut().map(|c| &mut **c),
visited_handling_mode,
self.quirks_mode,
);
let matched_then = matches_selector(
&dependency.selector,
dependency.selector_offset,
None,
&self.wrapper,
&mut context,
&mut |_, _| {},
);
(matched_then, context.relevant_link_found)
};
*relevant_link_found = relevant_link_found_now;
// Check for mismatches in both the match result and also the status
// of whether a relevant link was found.
matched_then != matches_now ||
relevant_link_found_now != relevant_link_found_then
}
fn scan_dependency(
&mut self,
dependency: &Dependency,
is_visited_dependent: VisitedDependent,
) {
debug!("TreeStyleInvalidator::scan_dependency({:?}, {:?}, {:?})",
self.element,
dependency,
is_visited_dependent);
if !self.dependency_may_be_relevant(dependency) {
return;
}
let mut relevant_link_found = false;
let should_account_for_dependency = self.check_dependency(
VisitedHandlingMode::AllLinksUnvisited,
dependency,
&mut relevant_link_found,
);
if should_account_for_dependency {
return self.note_dependency(dependency);
}
// If there is a relevant link, then we also matched in visited
// mode.
//
// Match again in this mode to ensure this also matches.
//
// Note that we never actually match directly against the element's true
// visited state at all, since that would expose us to timing attacks.
//
// The matching process only considers the relevant link state and
// visited handling mode when deciding if visited matches. Instead, we
// are rematching here in case there is some :visited selector whose
// matching result changed for some other state or attribute change of
// this element (for example, for things like [foo]:visited).
//
// NOTE: This thing is actually untested because testing it is flaky,
// see the tests that were added and then backed out in bug 1328509.
if is_visited_dependent == VisitedDependent::Yes && relevant_link_found {
let should_account_for_dependency = self.check_dependency(
VisitedHandlingMode::RelevantLinkVisited,
dependency,
&mut false,
);
if should_account_for_dependency {
return self.note_dependency(dependency);
}
}
}
fn note_dependency(&mut self, dependency: &Dependency) {
if dependency.affects_self() {
self.invalidates_self = true;
}
if dependency.affects_descendants() {
debug_assert_ne!(dependency.selector_offset, 0);
debug_assert!(!dependency.affects_later_siblings());
self.descendant_invalidations.push(Invalidation::new(
dependency.selector.clone(),
dependency.selector_offset,
));
} else if dependency.affects_later_siblings() {
debug_assert_ne!(dependency.selector_offset, 0);
self.sibling_invalidations.push(Invalidation::new(
dependency.selector.clone(),
dependency.selector_offset,
));
}
}
/// Returns whether `dependency` may cause us to invalidate the style of
/// more elements than what we've already invalidated.
fn dependency_may_be_relevant(&self, dependency: &Dependency) -> bool {
if dependency.affects_descendants() || dependency.affects_later_siblings() {
return true;
}
debug_assert!(dependency.affects_self());
!self.invalidates_self
}
}

423
components/style/invalidation/element/invalidator.rs
View file

@ -5,29 +5,34 @@
//! The struct that takes care of encapsulating all the logic on where and how
//! element styles need to be invalidated.
use Atom;
use context::{QuirksMode, SharedStyleContext, StackLimitChecker};
use context::{SharedStyleContext, StackLimitChecker};
use data::ElementData;
use dom::{TElement, TNode};
use element_state::{ElementState, IN_VISITED_OR_UNVISITED_STATE};
use invalidation::element::element_wrapper::{ElementSnapshot, ElementWrapper};
use invalidation::element::invalidation_map::*;
use invalidation::element::restyle_hints::*;
use selector_map::SelectorMap;
use selector_parser::{SelectorImpl, Snapshot};
use selector_parser::SelectorImpl;
use selectors::NthIndexCache;
use selectors::attr::CaseSensitivity;
use selectors::matching::{MatchingContext, MatchingMode, VisitedHandlingMode};
use selectors::matching::{matches_selector, matches_compound_selector};
use selectors::matching::CompoundSelectorMatchingResult;
use selectors::matching::matches_compound_selector;
use selectors::parser::{Combinator, Component, Selector};
use smallvec::SmallVec;
use std::fmt;
#[derive(Debug, PartialEq)]
enum VisitedDependent {
Yes,
No,
/// A trait to abstract the collection of invalidations for a given pass.
pub trait InvalidationCollector {
/// Collect invalidations for a given element's descendants and siblings.
///
/// Returns whether the element itself was invalidated.
fn collect_invalidations<E>(
element: E,
data: Option<&mut ElementData>,
nth_index_cache: Option<&mut NthIndexCache>,
shared_context: &SharedStyleContext,
descendant_invalidations: &mut InvalidationVector,
sibling_invalidations: &mut InvalidationVector,
) -> bool
where
E: TElement;
}
/// The struct that takes care of encapsulating all the logic on where and how
@ -51,7 +56,8 @@ pub struct TreeStyleInvalidator<'a, 'b: 'a, E>
nth_index_cache: Option<&'a mut NthIndexCache>,
}
type InvalidationVector = SmallVec<[Invalidation; 10]>;
/// A vector of invalidations, optimized for small invalidation sets.
pub type InvalidationVector = SmallVec<[Invalidation; 10]>;
/// The kind of invalidation we're processing.
///
@ -71,7 +77,7 @@ enum InvalidationKind {
/// must be restyled if the compound selector matches. Otherwise, if
/// describes which descendants (or later siblings) must be restyled.
#[derive(Clone)]
struct Invalidation {
pub struct Invalidation {
selector: Selector<SelectorImpl>,
offset: usize,
/// Whether the invalidation was already matched by any previous sibling or
@ -84,6 +90,15 @@ struct Invalidation {
}
impl Invalidation {
/// Create a new invalidation for a given selector and offset.
pub fn new(selector: Selector<SelectorImpl>, offset: usize) -> Self {
Self {
selector,
offset,
matched_by_any_previous: false,
}
}
/// Whether this invalidation is effective for the next sibling or
/// descendant after us.
fn effective_for_next(&self) -> bool {
@ -188,121 +203,25 @@ impl<'a, 'b: 'a, E> TreeStyleInvalidator<'a, 'b, E>
}
/// Perform the invalidation pass.
pub fn invalidate(mut self) -> InvalidationResult {
pub fn invalidate<C: InvalidationCollector>(mut self) -> InvalidationResult {
debug!("StyleTreeInvalidator::invalidate({:?})", self.element);
debug_assert!(self.element.has_snapshot(), "Why bothering?");
debug_assert!(self.data.is_some(), "How exactly?");
let shared_context = self.shared_context;
let wrapper =
ElementWrapper::new(self.element, shared_context.snapshot_map);
let state_changes = wrapper.state_changes();
let snapshot = wrapper.snapshot().expect("has_snapshot lied");
if !snapshot.has_attrs() && state_changes.is_empty() {
return InvalidationResult::empty();
}
// If we are sensitive to visitedness and the visited state changed, we
// force a restyle here. Matching doesn't depend on the actual visited
// state at all, so we can't look at matching results to decide what to
// do for this case.
if state_changes.intersects(IN_VISITED_OR_UNVISITED_STATE) {
trace!(" > visitedness change, force subtree restyle");
// We can't just return here because there may also be attribute
// changes as well that imply additional hints.
let data = self.data.as_mut().unwrap();
data.hint.insert(RestyleHint::restyle_subtree());
}
let mut classes_removed = SmallVec::<[Atom; 8]>::new();
let mut classes_added = SmallVec::<[Atom; 8]>::new();
if snapshot.class_changed() {
// TODO(emilio): Do this more efficiently!
snapshot.each_class(|c| {
if !self.element.has_class(c, CaseSensitivity::CaseSensitive) {
classes_removed.push(c.clone())
}
});
self.element.each_class(|c| {
if !snapshot.has_class(c, CaseSensitivity::CaseSensitive) {
classes_added.push(c.clone())
}
})
}
let mut id_removed = None;
let mut id_added = None;
if snapshot.id_changed() {
let old_id = snapshot.id_attr();
let current_id = self.element.get_id();
if old_id != current_id {
id_removed = old_id;
id_added = current_id;
}
}
let lookup_element =
if self.element.implemented_pseudo_element().is_some() {
self.element.pseudo_element_originating_element().unwrap()
} else {
self.element
};
let mut descendant_invalidations = InvalidationVector::new();
let mut sibling_invalidations = InvalidationVector::new();
let invalidated_self = {
let mut collector = InvalidationCollector {
wrapper,
lookup_element,
nth_index_cache: self.nth_index_cache.as_mut().map(|c| &mut **c),
state_changes,
element: self.element,
snapshot: &snapshot,
quirks_mode: self.shared_context.quirks_mode(),
removed_id: id_removed.as_ref(),
added_id: id_added.as_ref(),
classes_removed: &classes_removed,
classes_added: &classes_added,
descendant_invalidations: &mut descendant_invalidations,
sibling_invalidations: &mut sibling_invalidations,
invalidates_self: false,
};
shared_context.stylist.each_invalidation_map(|invalidation_map| {
collector.collect_dependencies_in_invalidation_map(invalidation_map);
});
// TODO(emilio): Consider storing dependencies from the UA sheet in
// a different map. If we do that, we can skip the stuff on the
// shared stylist iff cut_off_inheritance is true, and we can look
// just at that map.
let _cut_off_inheritance =
self.element.each_xbl_stylist(|stylist| {
// FIXME(emilio): Replace with assert / remove when we
// figure out what to do with the quirks mode mismatches
// (that is, when bug 1406875 is properly fixed).
collector.quirks_mode = stylist.quirks_mode();
stylist.each_invalidation_map(|invalidation_map| {
collector.collect_dependencies_in_invalidation_map(invalidation_map);
});
});
collector.invalidates_self
};
if invalidated_self {
if let Some(ref mut data) = self.data {
data.hint.insert(RESTYLE_SELF);
}
}
let invalidated_self = C::collect_invalidations(
self.element,
self.data.as_mut().map(|d| &mut **d),
self.nth_index_cache.as_mut().map(|c| &mut **c),
self.shared_context,
&mut descendant_invalidations,
&mut sibling_invalidations,
);
debug!("Collected invalidations (self: {}): ", invalidated_self);
debug!(" > descendants: {:?}", descendant_invalidations);
debug!(" > siblings: {:?}", sibling_invalidations);
let invalidated_descendants = self.invalidate_descendants(&descendant_invalidations);
let invalidated_siblings = self.invalidate_siblings(&mut sibling_invalidations);
@ -820,265 +739,3 @@ impl<'a, 'b: 'a, E> TreeStyleInvalidator<'a, 'b, E>
}
}
struct InvalidationCollector<'a, 'b: 'a, E>
where E: TElement,
{
element: E,
wrapper: ElementWrapper<'b, E>,
nth_index_cache: Option<&'a mut NthIndexCache>,
snapshot: &'a Snapshot,
quirks_mode: QuirksMode,
lookup_element: E,
removed_id: Option<&'a Atom>,
added_id: Option<&'a Atom>,
classes_removed: &'a SmallVec<[Atom; 8]>,
classes_added: &'a SmallVec<[Atom; 8]>,
state_changes: ElementState,
descendant_invalidations: &'a mut InvalidationVector,
sibling_invalidations: &'a mut InvalidationVector,
invalidates_self: bool,
}
impl<'a, 'b: 'a, E> InvalidationCollector<'a, 'b, E>
where E: TElement,
{
fn collect_dependencies_in_invalidation_map(
&mut self,
map: &InvalidationMap,
) {
let quirks_mode = self.quirks_mode;
let removed_id = self.removed_id;
if let Some(ref id) = removed_id {
if let Some(deps) = map.id_to_selector.get(id, quirks_mode) {
for dep in deps {
self.scan_dependency(dep, VisitedDependent::No);
}
}
}
let added_id = self.added_id;
if let Some(ref id) = added_id {
if let Some(deps) = map.id_to_selector.get(id, quirks_mode) {
for dep in deps {
self.scan_dependency(dep, VisitedDependent::No);
}
}
}
for class in self.classes_added.iter().chain(self.classes_removed.iter()) {
if let Some(deps) = map.class_to_selector.get(class, quirks_mode) {
for dep in deps {
self.scan_dependency(dep, VisitedDependent::No);
}
}
}
let should_examine_attribute_selector_map =
self.snapshot.other_attr_changed() ||
(self.snapshot.class_changed() && map.has_class_attribute_selectors) ||
(self.snapshot.id_changed() && map.has_id_attribute_selectors);
if should_examine_attribute_selector_map {
self.collect_dependencies_in_map(
&map.other_attribute_affecting_selectors
)
}
let state_changes = self.state_changes;
if !state_changes.is_empty() {
self.collect_state_dependencies(
&map.state_affecting_selectors,
state_changes,
)
}
}
fn collect_dependencies_in_map(
&mut self,
map: &SelectorMap<Dependency>,
) {
map.lookup_with_additional(
self.lookup_element,
self.quirks_mode,
self.removed_id,
self.classes_removed,
&mut |dependency| {
self.scan_dependency(dependency, VisitedDependent::No);
true
},
);
}
fn collect_state_dependencies(
&mut self,
map: &SelectorMap<StateDependency>,
state_changes: ElementState,
) {
map.lookup_with_additional(
self.lookup_element,
self.quirks_mode,
self.removed_id,
self.classes_removed,
&mut |dependency| {
if !dependency.state.intersects(state_changes) {
return true;
}
let visited_dependent =
if dependency.state.intersects(IN_VISITED_OR_UNVISITED_STATE) {
VisitedDependent::Yes
} else {
VisitedDependent::No
};
self.scan_dependency(&dependency.dep, visited_dependent);
true
},
);
}
/// Check whether a dependency should be taken into account, using a given
/// visited handling mode.
fn check_dependency(
&mut self,
visited_handling_mode: VisitedHandlingMode,
dependency: &Dependency,
relevant_link_found: &mut bool,
) -> bool {
let (matches_now, relevant_link_found_now) = {
let mut context = MatchingContext::new_for_visited(
MatchingMode::Normal,
None,
self.nth_index_cache.as_mut().map(|c| &mut **c),
visited_handling_mode,
self.quirks_mode,
);
let matches_now = matches_selector(
&dependency.selector,
dependency.selector_offset,
None,
&self.element,
&mut context,
&mut |_, _| {},
);
(matches_now, context.relevant_link_found)
};
let (matched_then, relevant_link_found_then) = {
let mut context = MatchingContext::new_for_visited(
MatchingMode::Normal,
None,
self.nth_index_cache.as_mut().map(|c| &mut **c),
visited_handling_mode,
self.quirks_mode,
);
let matched_then = matches_selector(
&dependency.selector,
dependency.selector_offset,
None,
&self.wrapper,
&mut context,
&mut |_, _| {},
);
(matched_then, context.relevant_link_found)
};
*relevant_link_found = relevant_link_found_now;
// Check for mismatches in both the match result and also the status
// of whether a relevant link was found.
matched_then != matches_now ||
relevant_link_found_now != relevant_link_found_then
}
fn scan_dependency(
&mut self,
dependency: &Dependency,
is_visited_dependent: VisitedDependent,
) {
debug!("TreeStyleInvalidator::scan_dependency({:?}, {:?}, {:?})",
self.element,
dependency,
is_visited_dependent);
if !self.dependency_may_be_relevant(dependency) {
return;
}
let mut relevant_link_found = false;
let should_account_for_dependency = self.check_dependency(
VisitedHandlingMode::AllLinksUnvisited,
dependency,
&mut relevant_link_found,
);
if should_account_for_dependency {
return self.note_dependency(dependency);
}
// If there is a relevant link, then we also matched in visited
// mode.
//
// Match again in this mode to ensure this also matches.
//
// Note that we never actually match directly against the element's true
// visited state at all, since that would expose us to timing attacks.
//
// The matching process only considers the relevant link state and
// visited handling mode when deciding if visited matches. Instead, we
// are rematching here in case there is some :visited selector whose
// matching result changed for some other state or attribute change of
// this element (for example, for things like [foo]:visited).
//
// NOTE: This thing is actually untested because testing it is flaky,
// see the tests that were added and then backed out in bug 1328509.
if is_visited_dependent == VisitedDependent::Yes && relevant_link_found {
let should_account_for_dependency = self.check_dependency(
VisitedHandlingMode::RelevantLinkVisited,
dependency,
&mut false,
);
if should_account_for_dependency {
return self.note_dependency(dependency);
}
}
}
fn note_dependency(&mut self, dependency: &Dependency) {
if dependency.affects_self() {
self.invalidates_self = true;
}
if dependency.affects_descendants() {
debug_assert_ne!(dependency.selector_offset, 0);
debug_assert!(!dependency.affects_later_siblings());
self.descendant_invalidations.push(Invalidation {
selector: dependency.selector.clone(),
offset: dependency.selector_offset,
matched_by_any_previous: false,
});
} else if dependency.affects_later_siblings() {
debug_assert_ne!(dependency.selector_offset, 0);
self.sibling_invalidations.push(Invalidation {
selector: dependency.selector.clone(),
offset: dependency.selector_offset,
matched_by_any_previous: false,
});
}
}
/// Returns whether `dependency` may cause us to invalidate the style of
/// more elements than what we've already invalidated.
fn dependency_may_be_relevant(&self, dependency: &Dependency) -> bool {
if dependency.affects_descendants() || dependency.affects_later_siblings() {
return true;
}
debug_assert!(dependency.affects_self());
!self.invalidates_self
}
}

1
components/style/invalidation/element/mod.rs
View file

@ -4,6 +4,7 @@
//! Invalidation of element styles due to attribute or style changes.
pub mod collector;
pub mod element_wrapper;
pub mod invalidation_map;
pub mod invalidator;