mirror of
https://github.com/servo/servo.git
synced 2025-08-03 12:40:06 +01:00
style: Implement a more fine-grained invalidation method.
This commit also removes the old restyle_hints module and splits it into multiple modules under components/style/invalidation/element/. The basic approach is to walk down the tree using compound selectors as needed, in order to do as little selector-matching as possible. Bug: 1368240 MozReview-Commit-ID: 2YO8fKFygZI
This commit is contained in:
parent
fd10729941
commit
cb06375fe2
21 changed files with 1673 additions and 1486 deletions
341
components/style/invalidation/element/element_wrapper.rs
Normal file
341
components/style/invalidation/element/element_wrapper.rs
Normal file
|
@ -0,0 +1,341 @@
|
|||
/* 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 wrapper over an element and a snapshot, that allows us to selector-match
|
||||
//! against a past state of the element.
|
||||
|
||||
use {Atom, CaseSensitivityExt, LocalName, Namespace};
|
||||
use dom::TElement;
|
||||
use element_state::ElementState;
|
||||
use selector_parser::{NonTSPseudoClass, PseudoElement, SelectorImpl, Snapshot, SnapshotMap, AttrValue};
|
||||
use selectors::Element;
|
||||
use selectors::attr::{AttrSelectorOperation, CaseSensitivity, NamespaceConstraint};
|
||||
use selectors::matching::{ElementSelectorFlags, LocalMatchingContext, MatchingContext};
|
||||
use selectors::matching::RelevantLinkStatus;
|
||||
use std::cell::Cell;
|
||||
use std::fmt;
|
||||
|
||||
/// In order to compute restyle hints, we perform a selector match against a
|
||||
/// list of partial selectors whose rightmost simple selector may be sensitive
|
||||
/// to the thing being changed. We do this matching twice, once for the element
|
||||
/// as it exists now and once for the element as it existed at the time of the
|
||||
/// last restyle. If the results of the selector match differ, that means that
|
||||
/// the given partial selector is sensitive to the change, and we compute a
|
||||
/// restyle hint based on its combinator.
|
||||
///
|
||||
/// In order to run selector matching against the old element state, we generate
|
||||
/// a wrapper for the element which claims to have the old state. This is the
|
||||
/// ElementWrapper logic below.
|
||||
///
|
||||
/// Gecko does this differently for element states, and passes a mask called
|
||||
/// mStateMask, which indicates the states that need to be ignored during
|
||||
/// selector matching. This saves an ElementWrapper allocation and an additional
|
||||
/// selector match call at the expense of additional complexity inside the
|
||||
/// selector matching logic. This only works for boolean states though, so we
|
||||
/// still need to take the ElementWrapper approach for attribute-dependent
|
||||
/// style. So we do it the same both ways for now to reduce complexity, but it's
|
||||
/// worth measuring the performance impact (if any) of the mStateMask approach.
|
||||
pub trait ElementSnapshot : Sized {
|
||||
/// The state of the snapshot, if any.
|
||||
fn state(&self) -> Option<ElementState>;
|
||||
|
||||
/// If this snapshot contains attribute information.
|
||||
fn has_attrs(&self) -> bool;
|
||||
|
||||
/// The ID attribute per this snapshot. Should only be called if
|
||||
/// `has_attrs()` returns true.
|
||||
fn id_attr(&self) -> Option<Atom>;
|
||||
|
||||
/// Whether this snapshot contains the class `name`. Should only be called
|
||||
/// if `has_attrs()` returns true.
|
||||
fn has_class(&self, name: &Atom, case_sensitivity: CaseSensitivity) -> bool;
|
||||
|
||||
/// A callback that should be called for each class of the snapshot. Should
|
||||
/// only be called if `has_attrs()` returns true.
|
||||
fn each_class<F>(&self, F)
|
||||
where F: FnMut(&Atom);
|
||||
|
||||
/// The `xml:lang=""` or `lang=""` attribute value per this snapshot.
|
||||
fn lang_attr(&self) -> Option<AttrValue>;
|
||||
}
|
||||
|
||||
/// A simple wrapper over an element and a snapshot, that allows us to
|
||||
/// selector-match against a past state of the element.
|
||||
#[derive(Clone)]
|
||||
pub struct ElementWrapper<'a, E>
|
||||
where E: TElement,
|
||||
{
|
||||
element: E,
|
||||
cached_snapshot: Cell<Option<&'a Snapshot>>,
|
||||
snapshot_map: &'a SnapshotMap,
|
||||
}
|
||||
|
||||
impl<'a, E> ElementWrapper<'a, E>
|
||||
where E: TElement,
|
||||
{
|
||||
/// Trivially constructs an `ElementWrapper`.
|
||||
pub fn new(el: E, snapshot_map: &'a SnapshotMap) -> Self {
|
||||
ElementWrapper {
|
||||
element: el,
|
||||
cached_snapshot: Cell::new(None),
|
||||
snapshot_map: snapshot_map,
|
||||
}
|
||||
}
|
||||
|
||||
/// Gets the snapshot associated with this element, if any.
|
||||
pub fn snapshot(&self) -> Option<&'a Snapshot> {
|
||||
if !self.element.has_snapshot() {
|
||||
return None;
|
||||
}
|
||||
|
||||
if let Some(s) = self.cached_snapshot.get() {
|
||||
return Some(s);
|
||||
}
|
||||
|
||||
let snapshot = self.snapshot_map.get(&self.element);
|
||||
debug_assert!(snapshot.is_some(), "has_snapshot lied!");
|
||||
|
||||
self.cached_snapshot.set(snapshot);
|
||||
|
||||
snapshot
|
||||
}
|
||||
|
||||
/// Returns the states that have changed since the element was snapshotted.
|
||||
pub fn state_changes(&self) -> ElementState {
|
||||
let snapshot = match self.snapshot() {
|
||||
Some(s) => s,
|
||||
None => return ElementState::empty(),
|
||||
};
|
||||
|
||||
match snapshot.state() {
|
||||
Some(state) => state ^ self.element.get_state(),
|
||||
None => ElementState::empty(),
|
||||
}
|
||||
}
|
||||
|
||||
/// Returns the value of the `xml:lang=""` (or, if appropriate, `lang=""`)
|
||||
/// attribute from this element's snapshot or the closest ancestor
|
||||
/// element snapshot with the attribute specified.
|
||||
fn get_lang(&self) -> Option<AttrValue> {
|
||||
let mut current = self.clone();
|
||||
loop {
|
||||
let lang = match self.snapshot() {
|
||||
Some(snapshot) if snapshot.has_attrs() => snapshot.lang_attr(),
|
||||
_ => current.element.lang_attr(),
|
||||
};
|
||||
if lang.is_some() {
|
||||
return lang;
|
||||
}
|
||||
match current.parent_element() {
|
||||
Some(parent) => current = parent,
|
||||
None => return None,
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, E> fmt::Debug for ElementWrapper<'a, E>
|
||||
where E: TElement,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
||||
// Ignore other fields for now, can change later if needed.
|
||||
self.element.fmt(f)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, E> Element for ElementWrapper<'a, E>
|
||||
where E: TElement,
|
||||
{
|
||||
type Impl = SelectorImpl;
|
||||
|
||||
fn match_non_ts_pseudo_class<F>(&self,
|
||||
pseudo_class: &NonTSPseudoClass,
|
||||
context: &mut LocalMatchingContext<Self::Impl>,
|
||||
relevant_link: &RelevantLinkStatus,
|
||||
_setter: &mut F)
|
||||
-> bool
|
||||
where F: FnMut(&Self, ElementSelectorFlags),
|
||||
{
|
||||
// Some pseudo-classes need special handling to evaluate them against
|
||||
// the snapshot.
|
||||
match *pseudo_class {
|
||||
#[cfg(feature = "gecko")]
|
||||
NonTSPseudoClass::MozAny(ref selectors) => {
|
||||
use selectors::matching::matches_complex_selector;
|
||||
return selectors.iter().any(|s| {
|
||||
matches_complex_selector(s.iter(), self, context, _setter)
|
||||
})
|
||||
}
|
||||
|
||||
// :dir is implemented in terms of state flags, but which state flag
|
||||
// it maps to depends on the argument to :dir. That means we can't
|
||||
// just add its state flags to the NonTSPseudoClass, because if we
|
||||
// added all of them there, and tested via intersects() here, we'd
|
||||
// get incorrect behavior for :not(:dir()) cases.
|
||||
//
|
||||
// FIXME(bz): How can I set this up so once Servo adds :dir()
|
||||
// support we don't forget to update this code?
|
||||
#[cfg(feature = "gecko")]
|
||||
NonTSPseudoClass::Dir(ref s) => {
|
||||
use invalidation::element::invalidation_map::dir_selector_to_state;
|
||||
let selector_flag = dir_selector_to_state(s);
|
||||
if selector_flag.is_empty() {
|
||||
// :dir() with some random argument; does not match.
|
||||
return false;
|
||||
}
|
||||
let state = match self.snapshot().and_then(|s| s.state()) {
|
||||
Some(snapshot_state) => snapshot_state,
|
||||
None => self.element.get_state(),
|
||||
};
|
||||
return state.contains(selector_flag);
|
||||
}
|
||||
|
||||
// For :link and :visited, we don't actually want to test the element
|
||||
// state directly. Instead, we use the `relevant_link` to determine if
|
||||
// they match.
|
||||
NonTSPseudoClass::Link => {
|
||||
return relevant_link.is_unvisited(self, context.shared);
|
||||
}
|
||||
NonTSPseudoClass::Visited => {
|
||||
return relevant_link.is_visited(self, context.shared);
|
||||
}
|
||||
|
||||
#[cfg(feature = "gecko")]
|
||||
NonTSPseudoClass::MozTableBorderNonzero => {
|
||||
if let Some(snapshot) = self.snapshot() {
|
||||
if snapshot.has_other_pseudo_class_state() {
|
||||
return snapshot.mIsTableBorderNonzero();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[cfg(feature = "gecko")]
|
||||
NonTSPseudoClass::MozBrowserFrame => {
|
||||
if let Some(snapshot) = self.snapshot() {
|
||||
if snapshot.has_other_pseudo_class_state() {
|
||||
return snapshot.mIsMozBrowserFrame();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// :lang() needs to match using the closest ancestor xml:lang="" or
|
||||
// lang="" attribtue from snapshots.
|
||||
NonTSPseudoClass::Lang(ref lang_arg) => {
|
||||
return self.element.match_element_lang(Some(self.get_lang()), lang_arg);
|
||||
}
|
||||
|
||||
_ => {}
|
||||
}
|
||||
|
||||
let flag = pseudo_class.state_flag();
|
||||
if flag.is_empty() {
|
||||
return self.element.match_non_ts_pseudo_class(pseudo_class,
|
||||
context,
|
||||
relevant_link,
|
||||
&mut |_, _| {})
|
||||
}
|
||||
match self.snapshot().and_then(|s| s.state()) {
|
||||
Some(snapshot_state) => snapshot_state.intersects(flag),
|
||||
None => {
|
||||
self.element.match_non_ts_pseudo_class(pseudo_class,
|
||||
context,
|
||||
relevant_link,
|
||||
&mut |_, _| {})
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn match_pseudo_element(&self,
|
||||
pseudo_element: &PseudoElement,
|
||||
context: &mut MatchingContext)
|
||||
-> bool
|
||||
{
|
||||
self.element.match_pseudo_element(pseudo_element, context)
|
||||
}
|
||||
|
||||
fn is_link(&self) -> bool {
|
||||
self.element.is_link()
|
||||
}
|
||||
|
||||
fn parent_element(&self) -> Option<Self> {
|
||||
self.element.parent_element()
|
||||
.map(|e| ElementWrapper::new(e, self.snapshot_map))
|
||||
}
|
||||
|
||||
fn first_child_element(&self) -> Option<Self> {
|
||||
self.element.first_child_element()
|
||||
.map(|e| ElementWrapper::new(e, self.snapshot_map))
|
||||
}
|
||||
|
||||
fn last_child_element(&self) -> Option<Self> {
|
||||
self.element.last_child_element()
|
||||
.map(|e| ElementWrapper::new(e, self.snapshot_map))
|
||||
}
|
||||
|
||||
fn prev_sibling_element(&self) -> Option<Self> {
|
||||
self.element.prev_sibling_element()
|
||||
.map(|e| ElementWrapper::new(e, self.snapshot_map))
|
||||
}
|
||||
|
||||
fn next_sibling_element(&self) -> Option<Self> {
|
||||
self.element.next_sibling_element()
|
||||
.map(|e| ElementWrapper::new(e, self.snapshot_map))
|
||||
}
|
||||
|
||||
fn is_html_element_in_html_document(&self) -> bool {
|
||||
self.element.is_html_element_in_html_document()
|
||||
}
|
||||
|
||||
fn get_local_name(&self) -> &<Self::Impl as ::selectors::SelectorImpl>::BorrowedLocalName {
|
||||
self.element.get_local_name()
|
||||
}
|
||||
|
||||
fn get_namespace(&self) -> &<Self::Impl as ::selectors::SelectorImpl>::BorrowedNamespaceUrl {
|
||||
self.element.get_namespace()
|
||||
}
|
||||
|
||||
fn attr_matches(&self,
|
||||
ns: &NamespaceConstraint<&Namespace>,
|
||||
local_name: &LocalName,
|
||||
operation: &AttrSelectorOperation<&AttrValue>)
|
||||
-> bool {
|
||||
match self.snapshot() {
|
||||
Some(snapshot) if snapshot.has_attrs() => {
|
||||
snapshot.attr_matches(ns, local_name, operation)
|
||||
}
|
||||
_ => self.element.attr_matches(ns, local_name, operation)
|
||||
}
|
||||
}
|
||||
|
||||
fn has_id(&self, id: &Atom, case_sensitivity: CaseSensitivity) -> bool {
|
||||
match self.snapshot() {
|
||||
Some(snapshot) if snapshot.has_attrs() => {
|
||||
snapshot.id_attr().map_or(false, |atom| case_sensitivity.eq_atom(&atom, id))
|
||||
}
|
||||
_ => self.element.has_id(id, case_sensitivity)
|
||||
}
|
||||
}
|
||||
|
||||
fn has_class(&self, name: &Atom, case_sensitivity: CaseSensitivity) -> bool {
|
||||
match self.snapshot() {
|
||||
Some(snapshot) if snapshot.has_attrs() => {
|
||||
snapshot.has_class(name, case_sensitivity)
|
||||
}
|
||||
_ => self.element.has_class(name, case_sensitivity)
|
||||
}
|
||||
}
|
||||
|
||||
fn is_empty(&self) -> bool {
|
||||
self.element.is_empty()
|
||||
}
|
||||
|
||||
fn is_root(&self) -> bool {
|
||||
self.element.is_root()
|
||||
}
|
||||
|
||||
fn pseudo_element_originating_element(&self) -> Option<Self> {
|
||||
self.element.closest_non_native_anonymous_ancestor()
|
||||
.map(|e| ElementWrapper::new(e, self.snapshot_map))
|
||||
}
|
||||
}
|
Loading…
Add table
Add a link
Reference in a new issue