style: Get rid of CurrentElementInfo.

It's out-of-band data I never liked, and the code has changed enough from when
it was introduced, that now all of the information it stores can be local.
This commit is contained in:
Emilio Cobos Álvarez 2017-11-09 16:01:55 +01:00
parent 49fe3d1c9f
commit 6704122927
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GPG key ID: 056B727BB9C1027C
3 changed files with 13 additions and 72 deletions

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.

View file

@ -298,13 +298,11 @@ 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);
}

View file

@ -273,6 +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") ||
@ -304,7 +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);
@ -427,7 +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(),
@ -524,8 +526,9 @@ where
data.reconstructed_self() ||
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 {
@ -535,6 +538,7 @@ where
data,
propagated_hint,
child_cascade_requirement,
is_initial_style,
note_child
);
}
@ -550,8 +554,6 @@ 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>(
@ -776,6 +778,7 @@ fn note_children<E, D, F>(
data: &ElementData,
propagated_hint: RestyleHint,
cascade_requirement: ChildCascadeRequirement,
is_initial_style: bool,
mut note_child: F,
)
where
@ -785,7 +788,6 @@ 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() {