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Auto merge of #19164 - emilio:more-traversal-cleanup, r=nox

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style: More traversal cleanup.

This is cleanup that allows me to fix https://bugzilla.mozilla.org/show_bug.cgi?id=1415013 in a more straight-forward way.

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This commit is contained in:
bors-servo 2017-11-15 06:51:27 -06:00 • committed by GitHub
commit d117694ecc
6 changed files with 67 additions and 179 deletions
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10
components/script/dom/document.rs
View file

@ -573,8 +573,14 @@ impl Document {
self.encoding.set(encoding);
}
pub fn content_and_heritage_changed(&self, node: &Node, damage: NodeDamage) {
node.dirty(damage);
pub fn content_and_heritage_changed(&self, node: &Node) {
if node.is_in_doc() {
node.note_dirty_descendants();
}
// FIXME(emilio): This is very inefficient, ideally the flag above would
// be enough and incremental layout could figure out from there.
node.dirty(NodeDamage::OtherNodeDamage);
}
/// Reflows and disarms the timer if the reflow timer has expired.

15
components/script/dom/node.rs
View file

@ -483,6 +483,19 @@ impl Node {
self.flags.set(flags);
}
// FIXME(emilio): This and the function below should move to Element.
pub fn note_dirty_descendants(&self) {
debug_assert!(self.is_in_doc());
for ancestor in self.inclusive_ancestors() {
if ancestor.get_flag(NodeFlags::HAS_DIRTY_DESCENDANTS) {
return;
}
ancestor.set_flag(NodeFlags::HAS_DIRTY_DESCENDANTS, true);
}
}
pub fn has_dirty_descendants(&self) -> bool {
self.get_flag(NodeFlags::HAS_DIRTY_DESCENDANTS)
}
@ -2499,7 +2512,7 @@ impl VirtualMethods for Node {
if let Some(list) = self.child_list.get() {
list.as_children_list().children_changed(mutation);
}
self.owner_doc().content_and_heritage_changed(self, NodeDamage::OtherNodeDamage);
self.owner_doc().content_and_heritage_changed(self);
}
// This handles the ranges mentioned in steps 2-3 when removing a node.

63
components/style/context.rs
View file

@ -5,11 +5,11 @@
//! The context within which style is calculated.
#[cfg(feature = "servo")] use animation::Animation;
#[cfg(feature = "servo")] use animation::PropertyAnimation;
use app_units::Au;
use bloom::StyleBloom;
use data::{EagerPseudoStyles, ElementData};
use dom::{OpaqueNode, TNode, TElement, SendElement};
use dom::{TElement, SendElement};
#[cfg(feature = "servo")] use dom::OpaqueNode;
use euclid::ScaleFactor;
use euclid::Size2D;
use fnv::FnvHashMap;
@ -285,23 +285,6 @@ impl ElementCascadeInputs {
}
}
/// Information about the current element being processed. We group this
/// together into a single struct within ThreadLocalStyleContext so that we can
/// instantiate and destroy it easily at the beginning and end of element
/// processing.
pub struct CurrentElementInfo {
/// The element being processed. Currently we use an OpaqueNode since we
/// only use this for identity checks, but we could use SendElement if there
/// were a good reason to.
element: OpaqueNode,
/// Whether the element is being styled for the first time.
is_initial_style: bool,
/// A Vec of possibly expired animations. Used only by Servo.
#[allow(dead_code)]
#[cfg(feature = "servo")]
pub possibly_expired_animations: Vec<PropertyAnimation>,
}
/// Statistics gathered during the traversal. We gather statistics on each
/// thread and then combine them after the threads join via the Add
/// implementation below.
@ -712,8 +695,6 @@ pub struct ThreadLocalStyleContext<E: TElement> {
pub selector_flags: SelectorFlagsMap<E>,
/// Statistics about the traversal.
pub statistics: TraversalStatistics,
/// Information related to the current element, non-None during processing.
pub current_element_info: Option<CurrentElementInfo>,
/// The struct used to compute and cache font metrics from style
/// for evaluation of the font-relative em/ch units and font-size
pub font_metrics_provider: E::FontMetricsProvider,
@ -736,7 +717,6 @@ impl<E: TElement> ThreadLocalStyleContext<E> {
tasks: SequentialTaskList(Vec::new()),
selector_flags: SelectorFlagsMap::new(),
statistics: TraversalStatistics::default(),
current_element_info: None,
font_metrics_provider: E::FontMetricsProvider::create_from(shared),
stack_limit_checker: StackLimitChecker::new(
(STYLE_THREAD_STACK_SIZE_KB - STACK_SAFETY_MARGIN_KB) * 1024),
@ -754,55 +734,16 @@ impl<E: TElement> ThreadLocalStyleContext<E> {
tasks: SequentialTaskList(Vec::new()),
selector_flags: SelectorFlagsMap::new(),
statistics: TraversalStatistics::default(),
current_element_info: None,
font_metrics_provider: E::FontMetricsProvider::create_from(shared),
stack_limit_checker: StackLimitChecker::new(
(STYLE_THREAD_STACK_SIZE_KB - STACK_SAFETY_MARGIN_KB) * 1024),
nth_index_cache: NthIndexCache::default(),
}
}
#[cfg(feature = "gecko")]
/// Notes when the style system starts traversing an element.
pub fn begin_element(&mut self, element: E, data: &ElementData) {
debug_assert!(self.current_element_info.is_none());
self.current_element_info = Some(CurrentElementInfo {
element: element.as_node().opaque(),
is_initial_style: !data.has_styles(),
});
}
#[cfg(feature = "servo")]
/// Notes when the style system starts traversing an element.
pub fn begin_element(&mut self, element: E, data: &ElementData) {
debug_assert!(self.current_element_info.is_none());
self.current_element_info = Some(CurrentElementInfo {
element: element.as_node().opaque(),
is_initial_style: !data.has_styles(),
possibly_expired_animations: Vec::new(),
});
}
/// Notes when the style system finishes traversing an element.
pub fn end_element(&mut self, element: E) {
debug_assert!(self.current_element_info.is_some());
debug_assert!(self.current_element_info.as_ref().unwrap().element ==
element.as_node().opaque());
self.current_element_info = None;
}
/// Returns true if the current element being traversed is being styled for
/// the first time.
///
/// Panics if called while no element is being traversed.
pub fn is_initial_style(&self) -> bool {
self.current_element_info.as_ref().unwrap().is_initial_style
}
}
impl<E: TElement> Drop for ThreadLocalStyleContext<E> {
fn drop(&mut self) {
debug_assert!(self.current_element_info.is_none());
debug_assert!(thread_state::get() == ThreadState::LAYOUT);
// Apply any slow selector flags that need to be set on parents.

44
components/style/data.rs
View file

@ -38,15 +38,16 @@ bitflags! {
/// traversed, so each traversal simply updates it with the appropriate
/// value.
const TRAVERSED_WITHOUT_STYLING = 1 << 1;
/// Whether we reframed/reconstructed any ancestor or self.
const ANCESTOR_WAS_RECONSTRUCTED = 1 << 2;
/// Whether the primary style of this element data was reused from another
/// element via a rule node comparison. This allows us to differentiate
/// between elements that shared styles because they met all the criteria
/// of the style sharing cache, compared to elements that reused style
/// structs via rule node identity. The former gives us stronger transitive
/// guarantees that allows us to apply the style sharing cache to cousins.
const PRIMARY_STYLE_REUSED_VIA_RULE_NODE = 1 << 3;
/// Whether the primary style of this element data was reused from
/// another element via a rule node comparison. This allows us to
/// differentiate between elements that shared styles because they met
/// all the criteria of the style sharing cache, compared to elements
/// that reused style structs via rule node identity.
///
/// The former gives us stronger transitive guarantees that allows us to
/// apply the style sharing cache to cousins.
const PRIMARY_STYLE_REUSED_VIA_RULE_NODE = 1 << 2;
}
}
@ -405,13 +406,7 @@ impl ElementData {
#[inline]
pub fn clear_restyle_flags_and_damage(&mut self) {
self.damage = RestyleDamage::empty();
self.flags.remove(ElementDataFlags::WAS_RESTYLED | ElementDataFlags::ANCESTOR_WAS_RECONSTRUCTED)
}
/// Returns whether this element or any ancestor is going to be
/// reconstructed.
pub fn reconstructed_self_or_ancestor(&self) -> bool {
self.reconstructed_ancestor() || self.reconstructed_self()
self.flags.remove(ElementDataFlags::WAS_RESTYLED);
}
/// Returns whether this element is going to be reconstructed.
@ -419,23 +414,6 @@ impl ElementData {
self.damage.contains(RestyleDamage::reconstruct())
}
/// Returns whether any ancestor of this element is going to be
/// reconstructed.
fn reconstructed_ancestor(&self) -> bool {
self.flags.contains(ElementDataFlags::ANCESTOR_WAS_RECONSTRUCTED)
}
/// Sets the flag that tells us whether we've reconstructed an ancestor.
pub fn set_reconstructed_ancestor(&mut self, reconstructed: bool) {
if reconstructed {
// If it weren't for animation-only traversals, we could assert
// `!self.reconstructed_ancestor()` here.
self.flags.insert(ElementDataFlags::ANCESTOR_WAS_RECONSTRUCTED);
} else {
self.flags.remove(ElementDataFlags::ANCESTOR_WAS_RECONSTRUCTED);
}
}
/// Mark this element as restyled, which is useful to know whether we need
/// to do a post-traversal.
pub fn set_restyled(&mut self) {

20
components/style/matching.rs
View file

@ -13,6 +13,7 @@ use data::ElementData;
use dom::TElement;
use invalidation::element::restyle_hints::RestyleHint;
use properties::ComputedValues;
use properties::longhands::display::computed_value as display;
use rule_tree::{CascadeLevel, StrongRuleNode};
use selector_parser::{PseudoElement, RestyleDamage};
use selectors::matching::ElementSelectorFlags;
@ -142,8 +143,6 @@ trait PrivateMatchMethods: TElement {
old_values: Option<&Arc<ComputedValues>>,
new_values: &ComputedValues,
) -> bool {
use properties::longhands::display::computed_value as display;
let new_box_style = new_values.get_box();
let has_new_animation_style = new_box_style.specifies_animations();
let has_animations = self.has_css_animations();
@ -182,7 +181,6 @@ trait PrivateMatchMethods: TElement {
restyle_hints: RestyleHint
) {
use context::PostAnimationTasks;
use properties::longhands::display::computed_value as display;
if !restyle_hints.intersects(RestyleHint::RESTYLE_SMIL) {
return;
@ -298,13 +296,11 @@ trait PrivateMatchMethods: TElement {
use animation;
use dom::TNode;
let possibly_expired_animations =
&mut context.thread_local.current_element_info.as_mut().unwrap()
.possibly_expired_animations;
let mut possibly_expired_animations = vec![];
let shared_context = context.shared;
if let Some(ref mut old) = *old_values {
self.update_animations_for_cascade(shared_context, old,
possibly_expired_animations,
&mut possibly_expired_animations,
&context.thread_local.font_metrics_provider);
}
@ -367,6 +363,16 @@ trait PrivateMatchMethods: TElement {
let old_display = old_values.get_box().clone_display();
let new_display = new_values.get_box().clone_display();
// If we used to be a display: none element, and no longer are,
// our children need to be restyled because they're unstyled.
//
// NOTE(emilio): Gecko has the special-case of -moz-binding, but
// that gets handled on the frame constructor when processing
// the reframe, so no need to handle that here.
if old_display == display::T::none && old_display != new_display {
return ChildCascadeRequirement::MustCascadeChildren
}
// Blockification of children may depend on our display value,
// so we need to actually do the recascade. We could potentially
// do better, but it doesn't seem worth it.

94
components/style/traversal.rs
View file

@ -159,13 +159,6 @@ pub trait DomTraversal<E: TElement> : Sync {
let parent_data = parent.as_ref().and_then(|p| p.borrow_data());
if let Some(ref mut data) = data {
// Make sure we don't have any stale RECONSTRUCTED_ANCESTOR bits
// from the last traversal (at a potentially-higher root).
//
// From the perspective of this traversal, the root cannot have
// reconstructed ancestors.
data.set_reconstructed_ancestor(false);
if !traversal_flags.for_animation_only() {
// Invalidate our style, and that of our siblings and
// descendants as needed.
@ -247,48 +240,6 @@ pub trait DomTraversal<E: TElement> : Sync {
_ => return true,
};
// If the element is native-anonymous and an ancestor frame will be
// reconstructed, the child and all its descendants will be destroyed.
// In that case, we wouldn't need to traverse the subtree...
//
// Except if there could be transitions of pseudo-elements, in which
// case we still need to process them, unfortunately.
//
// We need to conservatively continue the traversal to style the
// pseudo-element in order to properly process potentially-new
// transitions that we won't see otherwise.
//
// But it may be that we no longer match, so detect that case and act
// appropriately here.
if el.is_native_anonymous() {
if let Some(parent_data) = parent_data {
let going_to_reframe =
parent_data.reconstructed_self_or_ancestor();
let mut is_before_or_after_pseudo = false;
if let Some(pseudo) = el.implemented_pseudo_element() {
if pseudo.is_before_or_after() {
is_before_or_after_pseudo = true;
let still_match =
parent_data.styles.pseudos.get(&pseudo).is_some();
if !still_match {
debug_assert!(going_to_reframe,
"We're removing a pseudo, so we \
should reframe!");
return false;
}
}
}
if going_to_reframe && !is_before_or_after_pseudo {
debug!("Element {:?} is in doomed NAC subtree, \
culling traversal", el);
return false;
}
}
}
// If the dirty descendants bit is set, we need to traverse no matter
// what. Skip examining the ElementData.
if el.has_dirty_descendants() {
@ -322,6 +273,7 @@ pub trait DomTraversal<E: TElement> : Sync {
&self,
context: &mut StyleContext<E>,
parent: E,
is_initial_style: bool,
parent_data: &ElementData,
) -> bool {
debug_assert!(cfg!(feature = "gecko") ||
@ -353,7 +305,7 @@ pub trait DomTraversal<E: TElement> : Sync {
// happens, we may just end up doing wasted work, since Gecko
// recursively drops Servo ElementData when the XBL insertion parent of
// an Element is changed.
if cfg!(feature = "gecko") && context.thread_local.is_initial_style() &&
if cfg!(feature = "gecko") && is_initial_style &&
parent_data.styles.primary().has_moz_binding()
{
debug!("Parent {:?} has XBL binding, deferring traversal", parent);
@ -476,7 +428,8 @@ where
use traversal_flags::TraversalFlags;
let flags = context.shared.traversal_flags;
context.thread_local.begin_element(element, data);
let is_initial_style = !data.has_styles();
context.thread_local.statistics.elements_traversed += 1;
debug_assert!(flags.intersects(TraversalFlags::AnimationOnly | TraversalFlags::UnstyledOnly) ||
!element.has_snapshot() || element.handled_snapshot(),
@ -555,26 +508,24 @@ where
// Before examining each child individually, try to prove that our children
// don't need style processing. They need processing if any of the following
// conditions hold:
// * We have the dirty descendants bit.
// * We're propagating a hint.
// * This is the initial style.
// * We generated a reconstruct hint on self (which could mean that we
// switched from display:none to something else, which means the children
// need initial styling).
// * This is a servo non-incremental traversal.
//
// * We have the dirty descendants bit.
// * We're propagating a restyle hint.
// * We can't skip the cascade.
// * This is a servo non-incremental traversal.
//
// Additionally, there are a few scenarios where we avoid traversing the
// subtree even if descendant styles are out of date. These cases are
// enumerated in should_cull_subtree().
let mut traverse_children = has_dirty_descendants_for_this_restyle ||
!propagated_hint.is_empty() ||
!child_cascade_requirement.can_skip_cascade() ||
context.thread_local.is_initial_style() ||
data.reconstructed_self() ||
is_servo_nonincremental_layout();
let mut traverse_children =
has_dirty_descendants_for_this_restyle ||
!propagated_hint.is_empty() ||
!child_cascade_requirement.can_skip_cascade() ||
is_servo_nonincremental_layout();
traverse_children = traverse_children &&
!traversal.should_cull_subtree(context, element, &data);
traverse_children =
traverse_children &&
!traversal.should_cull_subtree(context, element, is_initial_style, &data);
// Examine our children, and enqueue the appropriate ones for traversal.
if traverse_children {
@ -584,7 +535,7 @@ where
data,
propagated_hint,
child_cascade_requirement,
data.reconstructed_self_or_ancestor(),
is_initial_style,
note_child
);
}
@ -600,8 +551,6 @@ where
!element.has_animation_only_dirty_descendants(),
"Should have cleared animation bits already");
clear_state_after_traversing(element, data, flags);
context.thread_local.end_element(element);
}
fn clear_state_after_traversing<E>(
@ -826,7 +775,7 @@ fn note_children<E, D, F>(
data: &ElementData,
propagated_hint: RestyleHint,
cascade_requirement: ChildCascadeRequirement,
reconstructed_ancestor: bool,
is_initial_style: bool,
mut note_child: F,
)
where
@ -836,7 +785,6 @@ where
{
trace!("note_children: {:?}", element);
let flags = context.shared.traversal_flags;
let is_initial_style = context.thread_local.is_initial_style();
// Loop over all the traversal children.
for child_node in element.traversal_children() {
@ -866,10 +814,6 @@ where
}
if let Some(ref mut child_data) = child_data {
// Propagate the parent restyle hint, that may make us restyle the whole
// subtree.
child_data.set_reconstructed_ancestor(reconstructed_ancestor);
let mut child_hint = propagated_hint;
match cascade_requirement {
ChildCascadeRequirement::CanSkipCascade => {}