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servo/components/style/stylist.rs
Emilio Cobos Álvarez 5fad3b4cde style: Add some scaffolding for @layer rules 
Not hooked anywhere yet, so this doesn't change behavior, but adds the
basic data model etc.

Adding parsing support requires some changes to cssparser to allow the
same at rule to be block and statement-like at the same time, so better
done separately.

Differential Revision: https://phabricator.services.mozilla.com/D124079
2023-05-26 15:23:25 +02:00

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/* 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 https://mozilla.org/MPL/2.0/. */
//! Selector matching.
use crate::applicable_declarations::{ApplicableDeclarationBlock, ApplicableDeclarationList};
use crate::context::{CascadeInputs, QuirksMode};
use crate::dom::{TElement, TShadowRoot};
use crate::element_state::{DocumentState, ElementState};
#[cfg(feature = "gecko")]
use crate::gecko_bindings::structs::{ServoStyleSetSizes, StyleRuleInclusion};
use crate::invalidation::element::invalidation_map::InvalidationMap;
use crate::invalidation::media_queries::{EffectiveMediaQueryResults, MediaListKey, ToMediaListKey};
use crate::invalidation::stylesheets::RuleChangeKind;
use crate::media_queries::Device;
use crate::properties::{self, CascadeMode, ComputedValues};
use crate::properties::{AnimationDeclarations, PropertyDeclarationBlock};
use crate::rule_cache::{RuleCache, RuleCacheConditions};
use crate::rule_collector::{containing_shadow_ignoring_svg_use, RuleCollector};
use crate::rule_tree::{CascadeLevel, RuleTree, StrongRuleNode, StyleSource};
use crate::selector_map::{PrecomputedHashMap, PrecomputedHashSet, SelectorMap, SelectorMapEntry};
use crate::selector_parser::{PerPseudoElementMap, PseudoElement, SelectorImpl, SnapshotMap};
use crate::shared_lock::{Locked, SharedRwLockReadGuard, StylesheetGuards};
use crate::stylesheet_set::{DataValidity, DocumentStylesheetSet, SheetRebuildKind};
use crate::stylesheet_set::{DocumentStylesheetFlusher, SheetCollectionFlusher};
use crate::stylesheets::keyframes_rule::KeyframesAnimation;
use crate::stylesheets::viewport_rule::{self, MaybeNew, ViewportRule};
use crate::stylesheets::{StyleRule, StylesheetInDocument, StylesheetContents};
#[cfg(feature = "gecko")]
use crate::stylesheets::{CounterStyleRule, FontFaceRule, FontFeatureValuesRule, PageRule};
use crate::stylesheets::{CssRule, Origin, OriginSet, PerOrigin, PerOriginIter};
use crate::thread_state::{self, ThreadState};
use crate::{Atom, LocalName, Namespace, WeakAtom};
use fallible::FallibleVec;
use hashglobe::FailedAllocationError;
use malloc_size_of::MallocSizeOf;
#[cfg(feature = "gecko")]
use malloc_size_of::{MallocShallowSizeOf, MallocSizeOfOps, MallocUnconditionalShallowSizeOf};
use selectors::attr::{CaseSensitivity, NamespaceConstraint};
use selectors::bloom::BloomFilter;
use selectors::matching::VisitedHandlingMode;
use selectors::matching::{matches_selector, ElementSelectorFlags, MatchingContext, MatchingMode};
use selectors::parser::{AncestorHashes, Combinator, Component, Selector, SelectorIter};
use selectors::visitor::SelectorVisitor;
use selectors::NthIndexCache;
use servo_arc::{Arc, ArcBorrow};
use smallbitvec::SmallBitVec;
use smallvec::SmallVec;
use std::sync::Mutex;
use std::{mem, ops};
use std::hash::{Hash, Hasher};
use style_traits::viewport::ViewportConstraints;
use fxhash::FxHashMap;
/// The type of the stylesheets that the stylist contains.
#[cfg(feature = "servo")]
pub type StylistSheet = crate::stylesheets::DocumentStyleSheet;
/// The type of the stylesheets that the stylist contains.
#[cfg(feature = "gecko")]
pub type StylistSheet = crate::gecko::data::GeckoStyleSheet;
#[derive(Debug, Clone)]
struct StylesheetContentsPtr(Arc<StylesheetContents>);
impl PartialEq for StylesheetContentsPtr {
#[inline]
fn eq(&self, other: &Self) -> bool {
Arc::ptr_eq(&self.0, &other.0)
}
}
impl Eq for StylesheetContentsPtr {}
impl Hash for StylesheetContentsPtr {
fn hash<H: Hasher>(&self, state: &mut H) {
let contents: &StylesheetContents = &*self.0;
(contents as *const StylesheetContents).hash(state)
}
}
type StyleSheetContentList = Vec<StylesheetContentsPtr>;
/// A key in the cascade data cache.
#[derive(Debug, Hash, Default, PartialEq, Eq)]
struct CascadeDataCacheKey {
media_query_results: Vec<MediaListKey>,
contents: StyleSheetContentList,
}
unsafe impl Send for CascadeDataCacheKey {}
unsafe impl Sync for CascadeDataCacheKey {}
trait CascadeDataCacheEntry : Sized {
/// Returns a reference to the cascade data.
fn cascade_data(&self) -> &CascadeData;
/// Rebuilds the cascade data for the new stylesheet collection. The
/// collection is guaranteed to be dirty.
fn rebuild<S>(
device: &Device,
quirks_mode: QuirksMode,
collection: SheetCollectionFlusher<S>,
guard: &SharedRwLockReadGuard,
old_entry: &Self,
) -> Result<Arc<Self>, FailedAllocationError>
where
S: StylesheetInDocument + PartialEq + 'static;
/// Measures heap memory usage.
#[cfg(feature = "gecko")]
fn add_size_of(&self, ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes);
}
struct CascadeDataCache<Entry> {
entries: FxHashMap<CascadeDataCacheKey, Arc<Entry>>,
}
impl<Entry> CascadeDataCache<Entry>
where
Entry: CascadeDataCacheEntry,
{
fn new() -> Self {
Self { entries: Default::default() }
}
fn len(&self) -> usize {
self.entries.len()
}
// FIXME(emilio): This may need to be keyed on quirks-mode too, though for
// UA sheets there aren't class / id selectors on those sheets, usually, so
// it's probably ok... For the other cache the quirks mode shouldn't differ
// so also should be fine.
fn lookup<'a, S>(
&'a mut self,
device: &Device,
quirks_mode: QuirksMode,
collection: SheetCollectionFlusher<S>,
guard: &SharedRwLockReadGuard,
old_entry: &Entry,
) -> Result<Option<Arc<Entry>>, FailedAllocationError>
where
S: StylesheetInDocument + PartialEq + 'static,
{
use std::collections::hash_map::Entry as HashMapEntry;
debug!("StyleSheetCache::lookup({})", self.len());
if !collection.dirty() {
return Ok(None);
}
let mut key = CascadeDataCacheKey::default();
for sheet in collection.sheets() {
CascadeData::collect_applicable_media_query_results_into(
device,
sheet,
guard,
&mut key.media_query_results,
&mut key.contents,
)
}
let new_entry;
match self.entries.entry(key) {
HashMapEntry::Vacant(e) => {
debug!("> Picking the slow path (not in the cache)");
new_entry = Entry::rebuild(
device,
quirks_mode,
collection,
guard,
old_entry,
)?;
e.insert(new_entry.clone());
}
HashMapEntry::Occupied(mut e) => {
// Avoid reusing our old entry (this can happen if we get
// invalidated due to CSSOM mutations and our old stylesheet
// contents were already unique, for example).
if !std::ptr::eq(&**e.get(), old_entry) {
if log_enabled!(log::Level::Debug) {
debug!("cache hit for:");
for sheet in collection.sheets() {
debug!(" > {:?}", sheet);
}
}
// The line below ensures the "committed" bit is updated
// properly.
collection.each(|_, _| true);
return Ok(Some(e.get().clone()));
}
debug!("> Picking the slow path due to same entry as old");
new_entry = Entry::rebuild(
device,
quirks_mode,
collection,
guard,
old_entry,
)?;
e.insert(new_entry.clone());
}
}
Ok(Some(new_entry))
}
/// Returns all the cascade datas that are not being used (that is, that are
/// held alive just by this cache).
///
/// We return them instead of dropping in place because some of them may
/// keep alive some other documents (like the SVG documents kept alive by
/// URL references), and thus we don't want to drop them while locking the
/// cache to not deadlock.
fn take_unused(&mut self) -> SmallVec<[Arc<Entry>; 3]> {
let mut unused = SmallVec::new();
self.entries.retain(|_key, value| {
// is_unique() returns false for static references, but we never
// have static references to UserAgentCascadeDatas. If we did, it
// may not make sense to put them in the cache in the first place.
if !value.is_unique() {
return true;
}
unused.push(value.clone());
false
});
unused
}
fn take_all(&mut self) -> FxHashMap<CascadeDataCacheKey, Arc<Entry>> {
mem::take(&mut self.entries)
}
#[cfg(feature = "gecko")]
fn add_size_of(&self, ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes) {
sizes.mOther += self.entries.shallow_size_of(ops);
for (_key, arc) in self.entries.iter() {
// These are primary Arc references that can be measured
// unconditionally.
sizes.mOther += arc.unconditional_shallow_size_of(ops);
arc.add_size_of(ops, sizes);
}
}
}
/// Measure heap usage of UA_CASCADE_DATA_CACHE.
#[cfg(feature = "gecko")]
pub fn add_size_of_ua_cache(ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes) {
UA_CASCADE_DATA_CACHE
.lock()
.unwrap()
.add_size_of(ops, sizes);
}
lazy_static! {
/// A cache of computed user-agent data, to be shared across documents.
static ref UA_CASCADE_DATA_CACHE: Mutex<UserAgentCascadeDataCache> =
Mutex::new(UserAgentCascadeDataCache::new());
}
impl CascadeDataCacheEntry for UserAgentCascadeData {
fn cascade_data(&self) -> &CascadeData {
&self.cascade_data
}
fn rebuild<S>(
device: &Device,
quirks_mode: QuirksMode,
collection: SheetCollectionFlusher<S>,
guard: &SharedRwLockReadGuard,
_old: &Self,
) -> Result<Arc<Self>, FailedAllocationError>
where
S: StylesheetInDocument + PartialEq + 'static
{
// TODO: Maybe we should support incremental rebuilds, though they seem
// uncommon and rebuild() doesn't deal with
// precomputed_pseudo_element_decls for now so...
let mut new_data = Self {
cascade_data: CascadeData::new(),
precomputed_pseudo_element_decls: PrecomputedPseudoElementDeclarations::default(),
};
for sheet in collection.sheets() {
new_data.cascade_data.add_stylesheet(
device,
quirks_mode,
sheet,
guard,
SheetRebuildKind::Full,
Some(&mut new_data.precomputed_pseudo_element_decls),
)?;
}
Ok(Arc::new(new_data))
}
#[cfg(feature = "gecko")]
fn add_size_of(&self, ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes) {
self.cascade_data.add_size_of(ops, sizes);
sizes.mPrecomputedPseudos += self.precomputed_pseudo_element_decls.size_of(ops);
}
}
type UserAgentCascadeDataCache = CascadeDataCache<UserAgentCascadeData>;
type PrecomputedPseudoElementDeclarations = PerPseudoElementMap<Vec<ApplicableDeclarationBlock>>;
#[derive(Default)]
struct UserAgentCascadeData {
cascade_data: CascadeData,
/// Applicable declarations for a given non-eagerly cascaded pseudo-element.
///
/// These are eagerly computed once, and then used to resolve the new
/// computed values on the fly on layout.
///
/// These are only filled from UA stylesheets.
precomputed_pseudo_element_decls: PrecomputedPseudoElementDeclarations,
}
/// All the computed information for all the stylesheets that apply to the
/// document.
#[derive(Default)]
#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
pub struct DocumentCascadeData {
#[cfg_attr(
feature = "servo",
ignore_malloc_size_of = "Arc, owned by UserAgentCascadeDataCache"
)]
user_agent: Arc<UserAgentCascadeData>,
user: CascadeData,
author: CascadeData,
per_origin: PerOrigin<()>,
}
/// An iterator over the cascade data of a given document.
pub struct DocumentCascadeDataIter<'a> {
iter: PerOriginIter<'a, ()>,
cascade_data: &'a DocumentCascadeData,
}
impl<'a> Iterator for DocumentCascadeDataIter<'a> {
type Item = (&'a CascadeData, Origin);
fn next(&mut self) -> Option<Self::Item> {
let (_, origin) = self.iter.next()?;
Some((self.cascade_data.borrow_for_origin(origin), origin))
}
}
impl DocumentCascadeData {
/// Borrows the cascade data for a given origin.
#[inline]
pub fn borrow_for_origin(&self, origin: Origin) -> &CascadeData {
match origin {
Origin::UserAgent => &self.user_agent.cascade_data,
Origin::Author => &self.author,
Origin::User => &self.user,
}
}
fn iter_origins(&self) -> DocumentCascadeDataIter {
DocumentCascadeDataIter {
iter: self.per_origin.iter_origins(),
cascade_data: self,
}
}
fn iter_origins_rev(&self) -> DocumentCascadeDataIter {
DocumentCascadeDataIter {
iter: self.per_origin.iter_origins_rev(),
cascade_data: self,
}
}
/// Rebuild the cascade data for the given document stylesheets, and
/// optionally with a set of user agent stylesheets. Returns Err(..)
/// to signify OOM.
fn rebuild<'a, S>(
&mut self,
device: &Device,
quirks_mode: QuirksMode,
mut flusher: DocumentStylesheetFlusher<'a, S>,
guards: &StylesheetGuards,
) -> Result<(), FailedAllocationError>
where
S: StylesheetInDocument + PartialEq + 'static,
{
// First do UA sheets.
{
let origin_flusher = flusher.flush_origin(Origin::UserAgent);
// Dirty check is just a minor optimization (no need to grab the
// lock if nothing has changed).
if origin_flusher.dirty() {
let mut ua_cache = UA_CASCADE_DATA_CACHE.lock().unwrap();
let new_data = ua_cache.lookup(
device,
quirks_mode,
origin_flusher,
guards.ua_or_user,
&self.user_agent,
)?;
if let Some(new_data) = new_data {
self.user_agent = new_data;
}
let _unused_entries = ua_cache.take_unused();
// See the comments in take_unused() as for why the following
// line.
std::mem::drop(ua_cache);
}
}
// Now do the user sheets.
self.user.rebuild(
device,
quirks_mode,
flusher.flush_origin(Origin::User),
guards.ua_or_user,
)?;
// And now the author sheets.
self.author.rebuild(
device,
quirks_mode,
flusher.flush_origin(Origin::Author),
guards.author,
)?;
Ok(())
}
/// Measures heap usage.
#[cfg(feature = "gecko")]
pub fn add_size_of(&self, ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes) {
self.user.add_size_of(ops, sizes);
self.author.add_size_of(ops, sizes);
}
}
/// Whether author styles are enabled.
///
/// This is used to support Gecko.
#[allow(missing_docs)]
#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq)]
pub enum AuthorStylesEnabled {
Yes,
No,
}
/// A wrapper over a DocumentStylesheetSet that can be `Sync`, since it's only
/// used and exposed via mutable methods in the `Stylist`.
#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
struct StylistStylesheetSet(DocumentStylesheetSet<StylistSheet>);
// Read above to see why this is fine.
unsafe impl Sync for StylistStylesheetSet {}
impl StylistStylesheetSet {
fn new() -> Self {
StylistStylesheetSet(DocumentStylesheetSet::new())
}
}
impl ops::Deref for StylistStylesheetSet {
type Target = DocumentStylesheetSet<StylistSheet>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl ops::DerefMut for StylistStylesheetSet {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}
/// This structure holds all the selectors and device characteristics
/// for a given document. The selectors are converted into `Rule`s
/// and sorted into `SelectorMap`s keyed off stylesheet origin and
/// pseudo-element (see `CascadeData`).
///
/// This structure is effectively created once per pipeline, in the
/// LayoutThread corresponding to that pipeline.
#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
pub struct Stylist {
/// Device that the stylist is currently evaluating against.
///
/// This field deserves a bigger comment due to the different use that Gecko
/// and Servo give to it (that we should eventually unify).
///
/// With Gecko, the device is never changed. Gecko manually tracks whether
/// the device data should be reconstructed, and "resets" the state of the
/// device.
///
/// On Servo, on the other hand, the device is a really cheap representation
/// that is recreated each time some constraint changes and calling
/// `set_device`.
device: Device,
/// Viewport constraints based on the current device.
viewport_constraints: Option<ViewportConstraints>,
/// The list of stylesheets.
stylesheets: StylistStylesheetSet,
/// A cache of CascadeDatas for AuthorStylesheetSets (i.e., shadow DOM).
#[cfg_attr(feature = "servo", ignore_malloc_size_of = "XXX: how to handle this?")]
author_data_cache: CascadeDataCache<CascadeData>,
/// If true, the quirks-mode stylesheet is applied.
#[cfg_attr(feature = "servo", ignore_malloc_size_of = "defined in selectors")]
quirks_mode: QuirksMode,
/// Selector maps for all of the style sheets in the stylist, after
/// evalutaing media rules against the current device, split out per
/// cascade level.
cascade_data: DocumentCascadeData,
/// Whether author styles are enabled.
author_styles_enabled: AuthorStylesEnabled,
/// The rule tree, that stores the results of selector matching.
rule_tree: RuleTree,
/// The total number of times the stylist has been rebuilt.
num_rebuilds: usize,
}
/// What cascade levels to include when styling elements.
#[derive(Clone, Copy, PartialEq)]
pub enum RuleInclusion {
/// Include rules for style sheets at all cascade levels. This is the
/// normal rule inclusion mode.
All,
/// Only include rules from UA and user level sheets. Used to implement
/// `getDefaultComputedStyle`.
DefaultOnly,
}
#[cfg(feature = "gecko")]
impl From<StyleRuleInclusion> for RuleInclusion {
fn from(value: StyleRuleInclusion) -> Self {
match value {
StyleRuleInclusion::All => RuleInclusion::All,
StyleRuleInclusion::DefaultOnly => RuleInclusion::DefaultOnly,
}
}
}
impl Stylist {
/// Construct a new `Stylist`, using given `Device` and `QuirksMode`.
/// If more members are added here, think about whether they should
/// be reset in clear().
#[inline]
pub fn new(device: Device, quirks_mode: QuirksMode) -> Self {
Self {
viewport_constraints: None,
device,
quirks_mode,
stylesheets: StylistStylesheetSet::new(),
author_data_cache: CascadeDataCache::new(),
cascade_data: Default::default(),
author_styles_enabled: AuthorStylesEnabled::Yes,
rule_tree: RuleTree::new(),
num_rebuilds: 0,
}
}
/// Returns the document cascade data.
#[inline]
pub fn cascade_data(&self) -> &DocumentCascadeData {
&self.cascade_data
}
/// Returns whether author styles are enabled or not.
#[inline]
pub fn author_styles_enabled(&self) -> AuthorStylesEnabled {
self.author_styles_enabled
}
/// Iterate through all the cascade datas from the document.
#[inline]
pub fn iter_origins(&self) -> DocumentCascadeDataIter {
self.cascade_data.iter_origins()
}
/// Does what the name says, to prevent author_data_cache to grow without
/// bound.
pub fn remove_unique_author_data_cache_entries(&mut self) {
self.author_data_cache.take_unused();
}
/// Rebuilds (if needed) the CascadeData given a sheet collection.
pub fn rebuild_author_data<S>(
&mut self,
old_data: &CascadeData,
collection: SheetCollectionFlusher<S>,
guard: &SharedRwLockReadGuard,
) -> Result<Option<Arc<CascadeData>>, FailedAllocationError>
where
S: StylesheetInDocument + PartialEq + 'static,
{
self.author_data_cache.lookup(
&self.device,
self.quirks_mode,
collection,
guard,
old_data,
)
}
/// Iterate over the extra data in origin order.
#[inline]
pub fn iter_extra_data_origins(&self) -> ExtraStyleDataIterator {
ExtraStyleDataIterator(self.cascade_data.iter_origins())
}
/// Iterate over the extra data in reverse origin order.
#[inline]
pub fn iter_extra_data_origins_rev(&self) -> ExtraStyleDataIterator {
ExtraStyleDataIterator(self.cascade_data.iter_origins_rev())
}
/// Returns the number of selectors.
pub fn num_selectors(&self) -> usize {
self.cascade_data
.iter_origins()
.map(|(d, _)| d.num_selectors)
.sum()
}
/// Returns the number of declarations.
pub fn num_declarations(&self) -> usize {
self.cascade_data
.iter_origins()
.map(|(d, _)| d.num_declarations)
.sum()
}
/// Returns the number of times the stylist has been rebuilt.
pub fn num_rebuilds(&self) -> usize {
self.num_rebuilds
}
/// Returns the number of revalidation_selectors.
pub fn num_revalidation_selectors(&self) -> usize {
self.cascade_data
.iter_origins()
.map(|(data, _)| data.selectors_for_cache_revalidation.len())
.sum()
}
/// Returns the number of entries in invalidation maps.
pub fn num_invalidations(&self) -> usize {
self.cascade_data
.iter_origins()
.map(|(data, _)| data.invalidation_map.len())
.sum()
}
/// Returns whether the given DocumentState bit is relied upon by a selector
/// of some rule.
pub fn has_document_state_dependency(&self, state: DocumentState) -> bool {
self.cascade_data
.iter_origins()
.any(|(d, _)| d.document_state_dependencies.intersects(state))
}
/// Flush the list of stylesheets if they changed, ensuring the stylist is
/// up-to-date.
pub fn flush<E>(
&mut self,
guards: &StylesheetGuards,
document_element: Option<E>,
snapshots: Option<&SnapshotMap>,
) -> bool
where
E: TElement,
{
if !self.stylesheets.has_changed() {
return false;
}
self.num_rebuilds += 1;
// Update viewport_constraints regardless of which origins'
// `CascadeData` we're updating.
self.viewport_constraints = None;
if viewport_rule::enabled() {
// TODO(emilio): This doesn't look so efficient.
//
// Presumably when we properly implement this we can at least have a
// bit on the stylesheet that says whether it contains viewport
// rules to skip it entirely?
//
// Processing it with the rest of rules seems tricky since it
// overrides the viewport size which may change the evaluation of
// media queries (or may not? how are viewport units in media
// queries defined?)
let cascaded_rule = ViewportRule {
declarations: viewport_rule::Cascade::from_stylesheets(
self.stylesheets.iter(),
guards,
&self.device,
)
.finish(),
};
self.viewport_constraints =
ViewportConstraints::maybe_new(&self.device, &cascaded_rule, self.quirks_mode);
if let Some(ref constraints) = self.viewport_constraints {
self.device.account_for_viewport_rule(constraints);
}
}
let flusher = self.stylesheets.flush(document_element, snapshots);
let had_invalidations = flusher.had_invalidations();
self.cascade_data
.rebuild(&self.device, self.quirks_mode, flusher, guards)
.unwrap_or_else(|_| warn!("OOM in Stylist::flush"));
had_invalidations
}
/// Insert a given stylesheet before another stylesheet in the document.
pub fn insert_stylesheet_before(
&mut self,
sheet: StylistSheet,
before_sheet: StylistSheet,
guard: &SharedRwLockReadGuard,
) {
self.stylesheets
.insert_stylesheet_before(Some(&self.device), sheet, before_sheet, guard)
}
/// Marks a given stylesheet origin as dirty, due to, for example, changes
/// in the declarations that affect a given rule.
///
/// FIXME(emilio): Eventually it'd be nice for this to become more
/// fine-grained.
pub fn force_stylesheet_origins_dirty(&mut self, origins: OriginSet) {
self.stylesheets.force_dirty(origins)
}
/// Sets whether author style is enabled or not.
pub fn set_author_styles_enabled(&mut self, enabled: AuthorStylesEnabled) {
self.author_styles_enabled = enabled;
}
/// Returns whether we've recorded any stylesheet change so far.
pub fn stylesheets_have_changed(&self) -> bool {
self.stylesheets.has_changed()
}
/// Appends a new stylesheet to the current set.
pub fn append_stylesheet(&mut self, sheet: StylistSheet, guard: &SharedRwLockReadGuard) {
self.stylesheets
.append_stylesheet(Some(&self.device), sheet, guard)
}
/// Remove a given stylesheet to the current set.
pub fn remove_stylesheet(&mut self, sheet: StylistSheet, guard: &SharedRwLockReadGuard) {
self.stylesheets
.remove_stylesheet(Some(&self.device), sheet, guard)
}
/// Notify of a change of a given rule.
pub fn rule_changed(
&mut self,
sheet: &StylistSheet,
rule: &CssRule,
guard: &SharedRwLockReadGuard,
change_kind: RuleChangeKind,
) {
self.stylesheets
.rule_changed(Some(&self.device), sheet, rule, guard, change_kind)
}
/// Appends a new stylesheet to the current set.
#[inline]
pub fn sheet_count(&self, origin: Origin) -> usize {
self.stylesheets.sheet_count(origin)
}
/// Appends a new stylesheet to the current set.
#[inline]
pub fn sheet_at(&self, origin: Origin, index: usize) -> Option<&StylistSheet> {
self.stylesheets.get(origin, index)
}
/// Returns whether for any of the applicable style rule data a given
/// condition is true.
pub fn any_applicable_rule_data<E, F>(&self, element: E, mut f: F) -> bool
where
E: TElement,
F: FnMut(&CascadeData) -> bool,
{
if f(&self.cascade_data.user_agent.cascade_data) {
return true;
}
let mut maybe = false;
let doc_author_rules_apply =
element.each_applicable_non_document_style_rule_data(|data, _| {
maybe = maybe || f(&*data);
});
if maybe || f(&self.cascade_data.user) {
return true;
}
doc_author_rules_apply && f(&self.cascade_data.author)
}
/// Computes the style for a given "precomputed" pseudo-element, taking the
/// universal rules and applying them.
pub fn precomputed_values_for_pseudo<E>(
&self,
guards: &StylesheetGuards,
pseudo: &PseudoElement,
parent: Option<&ComputedValues>,
) -> Arc<ComputedValues>
where
E: TElement,
{
debug_assert!(pseudo.is_precomputed());
let rule_node = self.rule_node_for_precomputed_pseudo(guards, pseudo, vec![]);
self.precomputed_values_for_pseudo_with_rule_node::<E>(guards, pseudo, parent, rule_node)
}
/// Computes the style for a given "precomputed" pseudo-element with
/// given rule node.
///
/// TODO(emilio): The type parameter could go away with a void type
/// implementing TElement.
pub fn precomputed_values_for_pseudo_with_rule_node<E>(
&self,
guards: &StylesheetGuards,
pseudo: &PseudoElement,
parent: Option<&ComputedValues>,
rules: StrongRuleNode,
) -> Arc<ComputedValues>
where
E: TElement,
{
self.compute_pseudo_element_style_with_inputs::<E>(
CascadeInputs {
rules: Some(rules),
visited_rules: None,
},
pseudo,
guards,
parent,
None,
)
}
/// Returns the rule node for a given precomputed pseudo-element.
///
/// If we want to include extra declarations to this precomputed
/// pseudo-element, we can provide a vector of ApplicableDeclarationBlocks
/// to extra_declarations. This is useful for @page rules.
pub fn rule_node_for_precomputed_pseudo(
&self,
guards: &StylesheetGuards,
pseudo: &PseudoElement,
mut extra_declarations: Vec<ApplicableDeclarationBlock>,
) -> StrongRuleNode {
let mut declarations_with_extra;
let declarations = match self
.cascade_data
.user_agent
.precomputed_pseudo_element_decls
.get(pseudo)
{
Some(declarations) => {
if !extra_declarations.is_empty() {
declarations_with_extra = declarations.clone();
declarations_with_extra.append(&mut extra_declarations);
&*declarations_with_extra
} else {
&**declarations
}
},
None => &[],
};
self.rule_tree.insert_ordered_rules_with_important(
declarations.into_iter().map(|a| a.clone().for_rule_tree()),
guards,
)
}
/// Returns the style for an anonymous box of the given type.
///
/// TODO(emilio): The type parameter could go away with a void type
/// implementing TElement.
#[cfg(feature = "servo")]
pub fn style_for_anonymous<E>(
&self,
guards: &StylesheetGuards,
pseudo: &PseudoElement,
parent_style: &ComputedValues,
) -> Arc<ComputedValues>
where
E: TElement,
{
self.precomputed_values_for_pseudo::<E>(guards, &pseudo, Some(parent_style))
}
/// Computes a pseudo-element style lazily during layout.
///
/// This can only be done for a certain set of pseudo-elements, like
/// :selection.
///
/// Check the documentation on lazy pseudo-elements in
/// docs/components/style.md
pub fn lazily_compute_pseudo_element_style<E>(
&self,
guards: &StylesheetGuards,
element: E,
pseudo: &PseudoElement,
rule_inclusion: RuleInclusion,
parent_style: &ComputedValues,
is_probe: bool,
matching_fn: Option<&dyn Fn(&PseudoElement) -> bool>,
) -> Option<Arc<ComputedValues>>
where
E: TElement,
{
let cascade_inputs = self.lazy_pseudo_rules(
guards,
element,
parent_style,
pseudo,
is_probe,
rule_inclusion,
matching_fn,
)?;
Some(self.compute_pseudo_element_style_with_inputs(
cascade_inputs,
pseudo,
guards,
Some(parent_style),
Some(element),
))
}
/// Computes a pseudo-element style lazily using the given CascadeInputs.
/// This can be used for truly lazy pseudo-elements or to avoid redoing
/// selector matching for eager pseudo-elements when we need to recompute
/// their style with a new parent style.
pub fn compute_pseudo_element_style_with_inputs<E>(
&self,
inputs: CascadeInputs,
pseudo: &PseudoElement,
guards: &StylesheetGuards,
parent_style: Option<&ComputedValues>,
element: Option<E>,
) -> Arc<ComputedValues>
where
E: TElement,
{
// FIXME(emilio): The lack of layout_parent_style here could be
// worrying, but we're probably dropping the display fixup for
// pseudos other than before and after, so it's probably ok.
//
// (Though the flags don't indicate so!)
//
// It'd be fine to assert that this isn't called with a parent style
// where display contents is in effect, but in practice this is hard to
// do for stuff like :-moz-fieldset-content with a
// <fieldset style="display: contents">. That is, the computed value of
// display for the fieldset is "contents", even though it's not the used
// value, so we don't need to adjust in a different way anyway.
self.cascade_style_and_visited(
element,
Some(pseudo),
inputs,
guards,
parent_style,
parent_style,
parent_style,
/* rule_cache = */ None,
&mut RuleCacheConditions::default(),
)
}
/// Computes a style using the given CascadeInputs. This can be used to
/// compute a style any time we know what rules apply and just need to use
/// the given parent styles.
///
/// parent_style is the style to inherit from for properties affected by
/// first-line ancestors.
///
/// parent_style_ignoring_first_line is the style to inherit from for
/// properties not affected by first-line ancestors.
///
/// layout_parent_style is the style used for some property fixups. It's
/// the style of the nearest ancestor with a layout box.
pub fn cascade_style_and_visited<E>(
&self,
element: Option<E>,
pseudo: Option<&PseudoElement>,
inputs: CascadeInputs,
guards: &StylesheetGuards,
parent_style: Option<&ComputedValues>,
parent_style_ignoring_first_line: Option<&ComputedValues>,
layout_parent_style: Option<&ComputedValues>,
rule_cache: Option<&RuleCache>,
rule_cache_conditions: &mut RuleCacheConditions,
) -> Arc<ComputedValues>
where
E: TElement,
{
debug_assert!(pseudo.is_some() || element.is_some(), "Huh?");
// We need to compute visited values if we have visited rules or if our
// parent has visited values.
let visited_rules = match inputs.visited_rules.as_ref() {
Some(rules) => Some(rules),
None => {
if parent_style.and_then(|s| s.visited_style()).is_some() {
Some(inputs.rules.as_ref().unwrap_or(self.rule_tree.root()))
} else {
None
}
},
};
// Read the comment on `precomputed_values_for_pseudo` to see why it's
// difficult to assert that display: contents nodes never arrive here
// (tl;dr: It doesn't apply for replaced elements and such, but the
// computed value is still "contents").
//
// FIXME(emilio): We should assert that it holds if pseudo.is_none()!
properties::cascade::<E>(
&self.device,
pseudo,
inputs.rules.as_ref().unwrap_or(self.rule_tree.root()),
guards,
parent_style,
parent_style_ignoring_first_line,
layout_parent_style,
visited_rules,
self.quirks_mode,
rule_cache,
rule_cache_conditions,
element,
)
}
/// Computes the cascade inputs for a lazily-cascaded pseudo-element.
///
/// See the documentation on lazy pseudo-elements in
/// docs/components/style.md
fn lazy_pseudo_rules<E>(
&self,
guards: &StylesheetGuards,
element: E,
parent_style: &ComputedValues,
pseudo: &PseudoElement,
is_probe: bool,
rule_inclusion: RuleInclusion,
matching_fn: Option<&dyn Fn(&PseudoElement) -> bool>,
) -> Option<CascadeInputs>
where
E: TElement,
{
debug_assert!(pseudo.is_lazy());
// Apply the selector flags. We should be in sequential mode
// already, so we can directly apply the parent flags.
let mut set_selector_flags = |element: &E, flags: ElementSelectorFlags| {
if cfg!(feature = "servo") {
// Servo calls this function from the worker, but only for internal
// pseudos, so we should never generate selector flags here.
unreachable!("internal pseudo generated slow selector flags?");
}
// No need to bother setting the selector flags when we're computing
// default styles.
if rule_inclusion == RuleInclusion::DefaultOnly {
return;
}
// Gecko calls this from sequential mode, so we can directly apply
// the flags.
debug_assert_eq!(thread_state::get(), ThreadState::LAYOUT);
let self_flags = flags.for_self();
if !self_flags.is_empty() {
unsafe {
element.set_selector_flags(self_flags);
}
}
let parent_flags = flags.for_parent();
if !parent_flags.is_empty() {
if let Some(p) = element.parent_element() {
unsafe {
p.set_selector_flags(parent_flags);
}
}
}
};
let mut declarations = ApplicableDeclarationList::new();
let mut matching_context = MatchingContext::new(
MatchingMode::ForStatelessPseudoElement,
None,
None,
self.quirks_mode,
);
matching_context.pseudo_element_matching_fn = matching_fn;
self.push_applicable_declarations(
element,
Some(&pseudo),
None,
None,
/* animation_declarations = */ Default::default(),
rule_inclusion,
&mut declarations,
&mut matching_context,
&mut set_selector_flags,
);
if declarations.is_empty() && is_probe {
return None;
}
let rules = self.rule_tree.compute_rule_node(&mut declarations, guards);
let mut visited_rules = None;
if parent_style.visited_style().is_some() {
let mut declarations = ApplicableDeclarationList::new();
let mut matching_context = MatchingContext::new_for_visited(
MatchingMode::ForStatelessPseudoElement,
None,
None,
VisitedHandlingMode::RelevantLinkVisited,
self.quirks_mode,
);
matching_context.pseudo_element_matching_fn = matching_fn;
self.push_applicable_declarations(
element,
Some(&pseudo),
None,
None,
/* animation_declarations = */ Default::default(),
rule_inclusion,
&mut declarations,
&mut matching_context,
&mut set_selector_flags,
);
if !declarations.is_empty() {
let rule_node = self.rule_tree.insert_ordered_rules_with_important(
declarations.drain(..).map(|a| a.for_rule_tree()),
guards,
);
if rule_node != *self.rule_tree.root() {
visited_rules = Some(rule_node);
}
}
}
Some(CascadeInputs {
rules: Some(rules),
visited_rules,
})
}
/// Set a given device, which may change the styles that apply to the
/// document.
///
/// Returns the sheet origins that were actually affected.
///
/// This means that we may need to rebuild style data even if the
/// stylesheets haven't changed.
///
/// Also, the device that arrives here may need to take the viewport rules
/// into account.
pub fn set_device(&mut self, mut device: Device, guards: &StylesheetGuards) -> OriginSet {
if viewport_rule::enabled() {
let cascaded_rule = {
let stylesheets = self.stylesheets.iter();
ViewportRule {
declarations: viewport_rule::Cascade::from_stylesheets(
stylesheets,
guards,
&device,
)
.finish(),
}
};
self.viewport_constraints =
ViewportConstraints::maybe_new(&device, &cascaded_rule, self.quirks_mode);
if let Some(ref constraints) = self.viewport_constraints {
device.account_for_viewport_rule(constraints);
}
}
self.device = device;
self.media_features_change_changed_style(guards, &self.device)
}
/// Returns whether, given a media feature change, any previously-applicable
/// style has become non-applicable, or vice-versa for each origin, using
/// `device`.
pub fn media_features_change_changed_style(
&self,
guards: &StylesheetGuards,
device: &Device,
) -> OriginSet {
debug!("Stylist::media_features_change_changed_style {:?}", device);
let mut origins = OriginSet::empty();
let stylesheets = self.stylesheets.iter();
for (stylesheet, origin) in stylesheets {
if origins.contains(origin.into()) {
continue;
}
let guard = guards.for_origin(origin);
let origin_cascade_data = self.cascade_data.borrow_for_origin(origin);
let affected_changed = !origin_cascade_data.media_feature_affected_matches(
stylesheet,
guard,
device,
self.quirks_mode,
);
if affected_changed {
origins |= origin;
}
}
origins
}
/// Returns the viewport constraints that apply to this document because of
/// a @viewport rule.
pub fn viewport_constraints(&self) -> Option<&ViewportConstraints> {
self.viewport_constraints.as_ref()
}
/// Returns the Quirks Mode of the document.
pub fn quirks_mode(&self) -> QuirksMode {
self.quirks_mode
}
/// Sets the quirks mode of the document.
pub fn set_quirks_mode(&mut self, quirks_mode: QuirksMode) {
if self.quirks_mode == quirks_mode {
return;
}
self.quirks_mode = quirks_mode;
self.force_stylesheet_origins_dirty(OriginSet::all());
}
/// Returns the applicable CSS declarations for the given element.
pub fn push_applicable_declarations<E, F>(
&self,
element: E,
pseudo_element: Option<&PseudoElement>,
style_attribute: Option<ArcBorrow<Locked<PropertyDeclarationBlock>>>,
smil_override: Option<ArcBorrow<Locked<PropertyDeclarationBlock>>>,
animation_declarations: AnimationDeclarations,
rule_inclusion: RuleInclusion,
applicable_declarations: &mut ApplicableDeclarationList,
context: &mut MatchingContext<E::Impl>,
flags_setter: &mut F,
) where
E: TElement,
F: FnMut(&E, ElementSelectorFlags),
{
RuleCollector::new(
self,
element,
pseudo_element,
style_attribute,
smil_override,
animation_declarations,
rule_inclusion,
applicable_declarations,
context,
flags_setter,
)
.collect_all();
}
/// Given an id, returns whether there might be any rules for that id in any
/// of our rule maps.
#[inline]
pub fn may_have_rules_for_id<E>(&self, id: &WeakAtom, element: E) -> bool
where
E: TElement,
{
// If id needs to be compared case-insensitively, the logic below
// wouldn't work. Just conservatively assume it may have such rules.
match self.quirks_mode().classes_and_ids_case_sensitivity() {
CaseSensitivity::AsciiCaseInsensitive => return true,
CaseSensitivity::CaseSensitive => {},
}
self.any_applicable_rule_data(element, |data| data.mapped_ids.contains(id))
}
/// Returns the registered `@keyframes` animation for the specified name.
#[inline]
pub fn get_animation<'a, E>(&'a self, name: &Atom, element: E) -> Option<&'a KeyframesAnimation>
where
E: TElement + 'a,
{
macro_rules! try_find_in {
($data:expr) => {
if let Some(animation) = $data.animations.get(name) {
return Some(animation);
}
};
}
// NOTE(emilio): We implement basically what Blink does for this case,
// which is [1] as of this writing.
//
// See [2] for the spec discussion about what to do about this. WebKit's
// behavior makes a bit more sense off-hand, but it's way more complex
// to implement, and it makes value computation having to thread around
// the cascade level, which is not great. Also, it breaks if you inherit
// animation-name from an element in a different tree.
//
// See [3] for the bug to implement whatever gets resolved, and related
// bugs for a bit more context.
//
// FIXME(emilio): This should probably work for pseudo-elements (i.e.,
// use rule_hash_target().shadow_root() instead of
// element.shadow_root()).
//
// [1]: https://cs.chromium.org/chromium/src/third_party/blink/renderer/
// core/css/resolver/style_resolver.cc?l=1267&rcl=90f9f8680ebb4a87d177f3b0833372ae4e0c88d8
// [2]: https://github.com/w3c/csswg-drafts/issues/1995
// [3]: https://bugzil.la/1458189
if let Some(shadow) = element.shadow_root() {
if let Some(data) = shadow.style_data() {
try_find_in!(data);
}
}
// Use the same rules to look for the containing host as we do for rule
// collection.
if let Some(shadow) = containing_shadow_ignoring_svg_use(element) {
if let Some(data) = shadow.style_data() {
try_find_in!(data);
}
} else {
try_find_in!(self.cascade_data.author);
}
try_find_in!(self.cascade_data.user);
try_find_in!(self.cascade_data.user_agent.cascade_data);
None
}
/// Computes the match results of a given element against the set of
/// revalidation selectors.
pub fn match_revalidation_selectors<E, F>(
&self,
element: E,
bloom: Option<&BloomFilter>,
nth_index_cache: &mut NthIndexCache,
flags_setter: &mut F,
) -> SmallBitVec
where
E: TElement,
F: FnMut(&E, ElementSelectorFlags),
{
// NB: `MatchingMode` doesn't really matter, given we don't share style
// between pseudos.
let mut matching_context = MatchingContext::new(
MatchingMode::Normal,
bloom,
Some(nth_index_cache),
self.quirks_mode,
);
// Note that, by the time we're revalidating, we're guaranteed that the
// candidate and the entry have the same id, classes, and local name.
// This means we're guaranteed to get the same rulehash buckets for all
// the lookups, which means that the bitvecs are comparable. We verify
// this in the caller by asserting that the bitvecs are same-length.
let mut results = SmallBitVec::new();
let matches_document_rules =
element.each_applicable_non_document_style_rule_data(|data, host| {
matching_context.with_shadow_host(Some(host), |matching_context| {
data.selectors_for_cache_revalidation.lookup(
element,
self.quirks_mode,
|selector_and_hashes| {
results.push(matches_selector(
&selector_and_hashes.selector,
selector_and_hashes.selector_offset,
Some(&selector_and_hashes.hashes),
&element,
matching_context,
flags_setter,
));
true
},
);
})
});
for (data, origin) in self.cascade_data.iter_origins() {
if origin == Origin::Author && !matches_document_rules {
continue;
}
data.selectors_for_cache_revalidation.lookup(
element,
self.quirks_mode,
|selector_and_hashes| {
results.push(matches_selector(
&selector_and_hashes.selector,
selector_and_hashes.selector_offset,
Some(&selector_and_hashes.hashes),
&element,
&mut matching_context,
flags_setter,
));
true
},
);
}
results
}
/// Computes styles for a given declaration with parent_style.
///
/// FIXME(emilio): the lack of pseudo / cascade flags look quite dubious,
/// hopefully this is only used for some canvas font stuff.
///
/// TODO(emilio): The type parameter can go away when
/// https://github.com/rust-lang/rust/issues/35121 is fixed.
pub fn compute_for_declarations<E>(
&self,
guards: &StylesheetGuards,
parent_style: &ComputedValues,
declarations: Arc<Locked<PropertyDeclarationBlock>>,
) -> Arc<ComputedValues>
where
E: TElement,
{
let block = declarations.read_with(guards.author);
// We don't bother inserting these declarations in the rule tree, since
// it'd be quite useless and slow.
//
// TODO(emilio): Now that we fixed bug 1493420, we should consider
// reversing this as it shouldn't be slow anymore, and should avoid
// generating two instantiations of apply_declarations.
properties::apply_declarations::<E, _>(
&self.device,
/* pseudo = */ None,
self.rule_tree.root(),
guards,
block
.declaration_importance_iter()
.map(|(declaration, _)| (declaration, Origin::Author)),
Some(parent_style),
Some(parent_style),
Some(parent_style),
CascadeMode::Unvisited {
visited_rules: None,
},
self.quirks_mode,
/* rule_cache = */ None,
&mut Default::default(),
/* element = */ None,
)
}
/// Accessor for a shared reference to the device.
#[inline]
pub fn device(&self) -> &Device {
&self.device
}
/// Accessor for a mutable reference to the device.
#[inline]
pub fn device_mut(&mut self) -> &mut Device {
&mut self.device
}
/// Accessor for a shared reference to the rule tree.
#[inline]
pub fn rule_tree(&self) -> &RuleTree {
&self.rule_tree
}
/// Measures heap usage.
#[cfg(feature = "gecko")]
pub fn add_size_of(&self, ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes) {
self.cascade_data.add_size_of(ops, sizes);
self.author_data_cache.add_size_of(ops, sizes);
sizes.mRuleTree += self.rule_tree.size_of(ops);
// We may measure other fields in the future if DMD says it's worth it.
}
/// Shutdown the static data that this module stores.
pub fn shutdown() {
let _entries = UA_CASCADE_DATA_CACHE.lock().unwrap().take_all();
}
}
/// This struct holds data which users of Stylist may want to extract
/// from stylesheets which can be done at the same time as updating.
#[derive(Clone, Debug, Default)]
#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
pub struct ExtraStyleData {
/// A list of effective font-face rules and their origin.
#[cfg(feature = "gecko")]
pub font_faces: Vec<Arc<Locked<FontFaceRule>>>,
/// A list of effective font-feature-values rules.
#[cfg(feature = "gecko")]
pub font_feature_values: Vec<Arc<Locked<FontFeatureValuesRule>>>,
/// A map of effective counter-style rules.
#[cfg(feature = "gecko")]
pub counter_styles: PrecomputedHashMap<Atom, Arc<Locked<CounterStyleRule>>>,
/// A map of effective page rules.
#[cfg(feature = "gecko")]
pub pages: Vec<Arc<Locked<PageRule>>>,
}
#[cfg(feature = "gecko")]
impl ExtraStyleData {
/// Add the given @font-face rule.
fn add_font_face(&mut self, rule: &Arc<Locked<FontFaceRule>>) {
self.font_faces.push(rule.clone());
}
/// Add the given @font-feature-values rule.
fn add_font_feature_values(&mut self, rule: &Arc<Locked<FontFeatureValuesRule>>) {
self.font_feature_values.push(rule.clone());
}
/// Add the given @counter-style rule.
fn add_counter_style(
&mut self,
guard: &SharedRwLockReadGuard,
rule: &Arc<Locked<CounterStyleRule>>,
) {
let name = rule.read_with(guard).name().0.clone();
self.counter_styles.insert(name, rule.clone());
}
/// Add the given @page rule.
fn add_page(&mut self, rule: &Arc<Locked<PageRule>>) {
self.pages.push(rule.clone());
}
}
impl ExtraStyleData {
fn clear(&mut self) {
#[cfg(feature = "gecko")]
{
self.font_faces.clear();
self.font_feature_values.clear();
self.counter_styles.clear();
self.pages.clear();
}
}
}
/// An iterator over the different ExtraStyleData.
pub struct ExtraStyleDataIterator<'a>(DocumentCascadeDataIter<'a>);
impl<'a> Iterator for ExtraStyleDataIterator<'a> {
type Item = (&'a ExtraStyleData, Origin);
fn next(&mut self) -> Option<Self::Item> {
self.0.next().map(|d| (&d.0.extra_data, d.1))
}
}
#[cfg(feature = "gecko")]
impl MallocSizeOf for ExtraStyleData {
/// Measure heap usage.
fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
let mut n = 0;
n += self.font_faces.shallow_size_of(ops);
n += self.font_feature_values.shallow_size_of(ops);
n += self.counter_styles.shallow_size_of(ops);
n += self.pages.shallow_size_of(ops);
n
}
}
/// SelectorMapEntry implementation for use in our revalidation selector map.
#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
#[derive(Clone, Debug)]
struct RevalidationSelectorAndHashes {
#[cfg_attr(
feature = "gecko",
ignore_malloc_size_of = "CssRules have primary refs, we measure there"
)]
selector: Selector<SelectorImpl>,
selector_offset: usize,
hashes: AncestorHashes,
}
impl RevalidationSelectorAndHashes {
fn new(selector: Selector<SelectorImpl>, hashes: AncestorHashes) -> Self {
let selector_offset = {
// We basically want to check whether the first combinator is a
// pseudo-element combinator. If it is, we want to use the offset
// one past it. Otherwise, our offset is 0.
let mut index = 0;
let mut iter = selector.iter();
// First skip over the first ComplexSelector.
//
// We can't check what sort of what combinator we have until we do
// that.
for _ in &mut iter {
index += 1; // Simple selector
}
match iter.next_sequence() {
Some(Combinator::PseudoElement) => index + 1, // +1 for the combinator
_ => 0,
}
};
RevalidationSelectorAndHashes {
selector,
selector_offset,
hashes,
}
}
}
impl SelectorMapEntry for RevalidationSelectorAndHashes {
fn selector(&self) -> SelectorIter<SelectorImpl> {
self.selector.iter_from(self.selector_offset)
}
}
/// A selector visitor implementation that collects all the state the Stylist
/// cares about a selector.
struct StylistSelectorVisitor<'a> {
/// Whether we've past the rightmost compound selector, not counting
/// pseudo-elements.
passed_rightmost_selector: bool,
/// Whether the selector needs revalidation for the style sharing cache.
needs_revalidation: &'a mut bool,
/// The filter with all the id's getting referenced from rightmost
/// selectors.
mapped_ids: &'a mut PrecomputedHashSet<Atom>,
/// The filter with the local names of attributes there are selectors for.
attribute_dependencies: &'a mut PrecomputedHashSet<LocalName>,
/// All the states selectors in the page reference.
state_dependencies: &'a mut ElementState,
/// All the document states selectors in the page reference.
document_state_dependencies: &'a mut DocumentState,
}
fn component_needs_revalidation(
c: &Component<SelectorImpl>,
passed_rightmost_selector: bool,
) -> bool {
match *c {
Component::ID(_) => {
// TODO(emilio): This could also check that the ID is not already in
// the rule hash. In that case, we could avoid making this a
// revalidation selector too.
//
// See https://bugzilla.mozilla.org/show_bug.cgi?id=1369611
passed_rightmost_selector
},
Component::AttributeInNoNamespaceExists { .. } |
Component::AttributeInNoNamespace { .. } |
Component::AttributeOther(_) |
Component::Empty |
Component::FirstChild |
Component::LastChild |
Component::OnlyChild |
Component::NthChild(..) |
Component::NthLastChild(..) |
Component::NthOfType(..) |
Component::NthLastOfType(..) |
Component::FirstOfType |
Component::LastOfType |
Component::OnlyOfType => true,
Component::NonTSPseudoClass(ref p) => p.needs_cache_revalidation(),
_ => false,
}
}
impl<'a> SelectorVisitor for StylistSelectorVisitor<'a> {
type Impl = SelectorImpl;
fn visit_complex_selector(&mut self, combinator: Option<Combinator>) -> bool {
*self.needs_revalidation =
*self.needs_revalidation || combinator.map_or(false, |c| c.is_sibling());
// NOTE(emilio): this call happens before we visit any of the simple
// selectors in the next ComplexSelector, so we can use this to skip
// looking at them.
self.passed_rightmost_selector = self.passed_rightmost_selector ||
!matches!(combinator, None | Some(Combinator::PseudoElement));
true
}
fn visit_selector_list(&mut self, list: &[Selector<Self::Impl>]) -> bool {
for selector in list {
let mut nested = StylistSelectorVisitor {
passed_rightmost_selector: false,
needs_revalidation: &mut *self.needs_revalidation,
attribute_dependencies: &mut *self.attribute_dependencies,
state_dependencies: &mut *self.state_dependencies,
document_state_dependencies: &mut *self.document_state_dependencies,
mapped_ids: &mut *self.mapped_ids,
};
let _ret = selector.visit(&mut nested);
debug_assert!(_ret, "We never return false");
}
true
}
fn visit_attribute_selector(
&mut self,
_ns: &NamespaceConstraint<&Namespace>,
name: &LocalName,
lower_name: &LocalName,
) -> bool {
self.attribute_dependencies.insert(name.clone());
self.attribute_dependencies.insert(lower_name.clone());
true
}
fn visit_simple_selector(&mut self, s: &Component<SelectorImpl>) -> bool {
*self.needs_revalidation = *self.needs_revalidation ||
component_needs_revalidation(s, self.passed_rightmost_selector);
match *s {
Component::NonTSPseudoClass(ref p) => {
self.state_dependencies.insert(p.state_flag());
self.document_state_dependencies
.insert(p.document_state_flag());
},
Component::ID(ref id) if !self.passed_rightmost_selector => {
// We want to stop storing mapped ids as soon as we've moved off
// the rightmost ComplexSelector that is not a pseudo-element.
//
// That can be detected by a visit_complex_selector call with a
// combinator other than None and PseudoElement.
//
// Importantly, this call happens before we visit any of the
// simple selectors in that ComplexSelector.
//
// NOTE(emilio): See the comment regarding on when this may
// break in visit_complex_selector.
self.mapped_ids.insert(id.0.clone());
},
_ => {},
}
true
}
}
/// A set of rules for element and pseudo-elements.
#[derive(Clone, Debug, Default, MallocSizeOf)]
struct GenericElementAndPseudoRules<Map> {
/// Rules from stylesheets at this `CascadeData`'s origin.
element_map: Map,
/// Rules from stylesheets at this `CascadeData`'s origin that correspond
/// to a given pseudo-element.
///
/// FIXME(emilio): There are a bunch of wasted entries here in practice.
/// Figure out a good way to do a `PerNonAnonBox` and `PerAnonBox` (for
/// `precomputed_values_for_pseudo`) without duplicating a lot of code.
pseudos_map: PerPseudoElementMap<Box<Map>>,
}
impl<Map: Default + MallocSizeOf> GenericElementAndPseudoRules<Map> {
#[inline(always)]
fn for_insertion(&mut self, pseudo_element: Option<&PseudoElement>) -> &mut Map {
debug_assert!(
pseudo_element.map_or(true, |pseudo| {
!pseudo.is_precomputed() && !pseudo.is_unknown_webkit_pseudo_element()
}),
"Precomputed pseudos should end up in precomputed_pseudo_element_decls, \
and unknown webkit pseudos should be discarded before getting here"
);
match pseudo_element {
None => &mut self.element_map,
Some(pseudo) => self
.pseudos_map
.get_or_insert_with(pseudo, || Box::new(Default::default())),
}
}
#[inline]
fn rules(&self, pseudo: Option<&PseudoElement>) -> Option<&Map> {
match pseudo {
Some(pseudo) => self.pseudos_map.get(pseudo).map(|p| &**p),
None => Some(&self.element_map),
}
}
/// Measures heap usage.
#[cfg(feature = "gecko")]
fn add_size_of(&self, ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes) {
sizes.mElementAndPseudosMaps += self.element_map.size_of(ops);
for elem in self.pseudos_map.iter() {
if let Some(ref elem) = *elem {
sizes.mElementAndPseudosMaps += <Box<_> as MallocSizeOf>::size_of(elem, ops);
}
}
}
}
type ElementAndPseudoRules = GenericElementAndPseudoRules<SelectorMap<Rule>>;
type PartMap = PrecomputedHashMap<Atom, SmallVec<[Rule; 1]>>;
type PartElementAndPseudoRules = GenericElementAndPseudoRules<PartMap>;
impl ElementAndPseudoRules {
// TODO(emilio): Should we retain storage of these?
fn clear(&mut self) {
self.element_map.clear();
self.pseudos_map.clear();
}
}
impl PartElementAndPseudoRules {
// TODO(emilio): Should we retain storage of these?
fn clear(&mut self) {
self.element_map.clear();
self.pseudos_map.clear();
}
}
/// Data resulting from performing the CSS cascade that is specific to a given
/// origin.
///
/// FIXME(emilio): Consider renaming and splitting in `CascadeData` and
/// `InvalidationData`? That'd make `clear_cascade_data()` clearer.
#[derive(Debug, Clone, MallocSizeOf)]
pub struct CascadeData {
/// The data coming from normal style rules that apply to elements at this
/// cascade level.
normal_rules: ElementAndPseudoRules,
/// The `:host` pseudo rules that are the rightmost selector (without
/// accounting for pseudo-elements).
host_rules: Option<Box<ElementAndPseudoRules>>,
/// The data coming from ::slotted() pseudo-element rules.
///
/// We need to store them separately because an element needs to match
/// ::slotted() pseudo-element rules in different shadow roots.
///
/// In particular, we need to go through all the style data in all the
/// containing style scopes starting from the closest assigned slot.
slotted_rules: Option<Box<ElementAndPseudoRules>>,
/// The data coming from ::part() pseudo-element rules.
///
/// We need to store them separately because an element needs to match
/// ::part() pseudo-element rules in different shadow roots.
part_rules: Option<Box<PartElementAndPseudoRules>>,
/// The invalidation map for these rules.
invalidation_map: InvalidationMap,
/// The attribute local names that appear in attribute selectors. Used
/// to avoid taking element snapshots when an irrelevant attribute changes.
/// (We don't bother storing the namespace, since namespaced attributes are
/// rare.)
attribute_dependencies: PrecomputedHashSet<LocalName>,
/// The element state bits that are relied on by selectors. Like
/// `attribute_dependencies`, this is used to avoid taking element snapshots
/// when an irrelevant element state bit changes.
state_dependencies: ElementState,
/// The document state bits that are relied on by selectors. This is used
/// to tell whether we need to restyle the entire document when a document
/// state bit changes.
document_state_dependencies: DocumentState,
/// The ids that appear in the rightmost complex selector of selectors (and
/// hence in our selector maps). Used to determine when sharing styles is
/// safe: we disallow style sharing for elements whose id matches this
/// filter, and hence might be in one of our selector maps.
mapped_ids: PrecomputedHashSet<Atom>,
/// Selectors that require explicit cache revalidation (i.e. which depend
/// on state that is not otherwise visible to the cache, like attributes or
/// tree-structural state like child index and pseudos).
#[ignore_malloc_size_of = "Arc"]
selectors_for_cache_revalidation: SelectorMap<RevalidationSelectorAndHashes>,
/// A map with all the animations at this `CascadeData`'s origin, indexed
/// by name.
animations: PrecomputedHashMap<Atom, KeyframesAnimation>,
/// Effective media query results cached from the last rebuild.
effective_media_query_results: EffectiveMediaQueryResults,
/// Extra data, like different kinds of rules, etc.
extra_data: ExtraStyleData,
/// A monotonically increasing counter to represent the order on which a
/// style rule appears in a stylesheet, needed to sort them by source order.
rules_source_order: u32,
/// The total number of selectors.
num_selectors: usize,
/// The total number of declarations.
num_declarations: usize,
}
impl CascadeData {
/// Creates an empty `CascadeData`.
pub fn new() -> Self {
Self {
normal_rules: ElementAndPseudoRules::default(),
host_rules: None,
slotted_rules: None,
part_rules: None,
invalidation_map: InvalidationMap::new(),
attribute_dependencies: PrecomputedHashSet::default(),
state_dependencies: ElementState::empty(),
document_state_dependencies: DocumentState::empty(),
mapped_ids: PrecomputedHashSet::default(),
selectors_for_cache_revalidation: SelectorMap::new(),
animations: Default::default(),
extra_data: ExtraStyleData::default(),
effective_media_query_results: EffectiveMediaQueryResults::new(),
rules_source_order: 0,
num_selectors: 0,
num_declarations: 0,
}
}
/// Rebuild the cascade data from a given SheetCollection, incrementally if
/// possible.
pub fn rebuild<'a, S>(
&mut self,
device: &Device,
quirks_mode: QuirksMode,
collection: SheetCollectionFlusher<S>,
guard: &SharedRwLockReadGuard,
) -> Result<(), FailedAllocationError>
where
S: StylesheetInDocument + PartialEq + 'static,
{
if !collection.dirty() {
return Ok(());
}
let validity = collection.data_validity();
match validity {
DataValidity::Valid => {},
DataValidity::CascadeInvalid => self.clear_cascade_data(),
DataValidity::FullyInvalid => self.clear(),
}
let mut result = Ok(());
collection.each(|stylesheet, rebuild_kind| {
result = self.add_stylesheet(
device,
quirks_mode,
stylesheet,
guard,
rebuild_kind,
/* precomputed_pseudo_element_decls = */ None,
);
result.is_ok()
});
result
}
/// Returns the invalidation map.
pub fn invalidation_map(&self) -> &InvalidationMap {
&self.invalidation_map
}
/// Returns whether the given ElementState bit is relied upon by a selector
/// of some rule.
#[inline]
pub fn has_state_dependency(&self, state: ElementState) -> bool {
self.state_dependencies.intersects(state)
}
/// Returns whether the given attribute might appear in an attribute
/// selector of some rule.
#[inline]
pub fn might_have_attribute_dependency(&self, local_name: &LocalName) -> bool {
self.attribute_dependencies.contains(local_name)
}
/// Returns the normal rule map for a given pseudo-element.
#[inline]
pub fn normal_rules(&self, pseudo: Option<&PseudoElement>) -> Option<&SelectorMap<Rule>> {
self.normal_rules.rules(pseudo)
}
/// Returns the host pseudo rule map for a given pseudo-element.
#[inline]
pub fn host_rules(&self, pseudo: Option<&PseudoElement>) -> Option<&SelectorMap<Rule>> {
self.host_rules.as_ref().and_then(|d| d.rules(pseudo))
}
/// Whether there's any host rule that could match in this scope.
pub fn any_host_rules(&self) -> bool {
self.host_rules.is_some()
}
/// Returns the slotted rule map for a given pseudo-element.
#[inline]
pub fn slotted_rules(&self, pseudo: Option<&PseudoElement>) -> Option<&SelectorMap<Rule>> {
self.slotted_rules.as_ref().and_then(|d| d.rules(pseudo))
}
/// Whether there's any ::slotted rule that could match in this scope.
pub fn any_slotted_rule(&self) -> bool {
self.slotted_rules.is_some()
}
/// Returns the parts rule map for a given pseudo-element.
#[inline]
pub fn part_rules(&self, pseudo: Option<&PseudoElement>) -> Option<&PartMap> {
self.part_rules.as_ref().and_then(|d| d.rules(pseudo))
}
/// Whether there's any ::part rule that could match in this scope.
pub fn any_part_rule(&self) -> bool {
self.part_rules.is_some()
}
/// Collects all the applicable media query results into `results`.
///
/// This duplicates part of the logic in `add_stylesheet`, which is
/// a bit unfortunate.
///
/// FIXME(emilio): With a bit of smartness in
/// `media_feature_affected_matches`, we could convert
/// `EffectiveMediaQueryResults` into a vector without too much effort.
fn collect_applicable_media_query_results_into<S>(
device: &Device,
stylesheet: &S,
guard: &SharedRwLockReadGuard,
results: &mut Vec<MediaListKey>,
contents_list: &mut StyleSheetContentList,
) where
S: StylesheetInDocument + 'static,
{
if !stylesheet.enabled() || !stylesheet.is_effective_for_device(device, guard) {
return;
}
debug!(" + {:?}", stylesheet);
let contents = stylesheet.contents();
results.push(contents.to_media_list_key());
// Safety: StyleSheetContents are reference-counted with Arc.
contents_list.push(StylesheetContentsPtr(unsafe {
Arc::from_raw_addrefed(contents)
}));
for rule in stylesheet.effective_rules(device, guard) {
match *rule {
CssRule::Import(ref lock) => {
let import_rule = lock.read_with(guard);
debug!(" + {:?}", import_rule.stylesheet.media(guard));
results.push(import_rule.to_media_list_key());
},
CssRule::Media(ref lock) => {
let media_rule = lock.read_with(guard);
debug!(" + {:?}", media_rule.media_queries.read_with(guard));
results.push(media_rule.to_media_list_key());
},
_ => {},
}
}
}
// Returns Err(..) to signify OOM
fn add_stylesheet<S>(
&mut self,
device: &Device,
quirks_mode: QuirksMode,
stylesheet: &S,
guard: &SharedRwLockReadGuard,
rebuild_kind: SheetRebuildKind,
mut precomputed_pseudo_element_decls: Option<&mut PrecomputedPseudoElementDeclarations>,
) -> Result<(), FailedAllocationError>
where
S: StylesheetInDocument + 'static,
{
if !stylesheet.enabled() || !stylesheet.is_effective_for_device(device, guard) {
return Ok(());
}
let contents = stylesheet.contents();
let origin = contents.origin;
if rebuild_kind.should_rebuild_invalidation() {
self.effective_media_query_results.saw_effective(contents);
}
for rule in stylesheet.effective_rules(device, guard) {
match *rule {
CssRule::Style(ref locked) => {
let style_rule = locked.read_with(&guard);
self.num_declarations += style_rule.block.read_with(&guard).len();
for selector in &style_rule.selectors.0 {
self.num_selectors += 1;
let pseudo_element = selector.pseudo_element();
if let Some(pseudo) = pseudo_element {
if pseudo.is_precomputed() {
debug_assert!(selector.is_universal());
debug_assert!(matches!(origin, Origin::UserAgent));
precomputed_pseudo_element_decls
.as_mut()
.expect("Expected precomputed declarations for the UA level")
.get_or_insert_with(pseudo, Vec::new)
.push(ApplicableDeclarationBlock::new(
StyleSource::from_rule(locked.clone()),
self.rules_source_order,
CascadeLevel::UANormal,
selector.specificity(),
));
continue;
}
if pseudo.is_unknown_webkit_pseudo_element() {
continue;
}
}
let hashes = AncestorHashes::new(&selector, quirks_mode);
let rule = Rule::new(
selector.clone(),
hashes,
locked.clone(),
self.rules_source_order,
);
if rebuild_kind.should_rebuild_invalidation() {
self.invalidation_map.note_selector(selector, quirks_mode)?;
let mut needs_revalidation = false;
let mut visitor = StylistSelectorVisitor {
needs_revalidation: &mut needs_revalidation,
passed_rightmost_selector: false,
attribute_dependencies: &mut self.attribute_dependencies,
state_dependencies: &mut self.state_dependencies,
document_state_dependencies: &mut self.document_state_dependencies,
mapped_ids: &mut self.mapped_ids,
};
rule.selector.visit(&mut visitor);
if needs_revalidation {
self.selectors_for_cache_revalidation.insert(
RevalidationSelectorAndHashes::new(
rule.selector.clone(),
rule.hashes.clone(),
),
quirks_mode,
)?;
}
}
// Part is special, since given it doesn't have any
// selectors inside, it's not worth using a whole
// SelectorMap for it.
if let Some(parts) = selector.parts() {
// ::part() has all semantics, so we just need to
// put any of them in the selector map.
//
// We choose the last one quite arbitrarily,
// expecting it's slightly more likely to be more
// specific.
self.part_rules
.get_or_insert_with(|| Box::new(Default::default()))
.for_insertion(pseudo_element)
.try_entry(parts.last().unwrap().clone().0)?
.or_insert_with(SmallVec::new)
.try_push(rule)?;
} else {
// NOTE(emilio): It's fine to look at :host and then at
// ::slotted(..), since :host::slotted(..) could never
// possibly match, as <slot> is not a valid shadow host.
let rules =
if selector.is_featureless_host_selector_or_pseudo_element() {
self.host_rules
.get_or_insert_with(|| Box::new(Default::default()))
} else if selector.is_slotted() {
self.slotted_rules
.get_or_insert_with(|| Box::new(Default::default()))
} else {
&mut self.normal_rules
}
.for_insertion(pseudo_element);
rules.insert(rule, quirks_mode)?;
}
}
self.rules_source_order += 1;
},
CssRule::Import(ref lock) => {
if rebuild_kind.should_rebuild_invalidation() {
let import_rule = lock.read_with(guard);
self.effective_media_query_results
.saw_effective(import_rule);
}
// NOTE: effective_rules visits the inner stylesheet if
// appropriate.
},
CssRule::Media(ref lock) => {
if rebuild_kind.should_rebuild_invalidation() {
let media_rule = lock.read_with(guard);
self.effective_media_query_results.saw_effective(media_rule);
}
},
CssRule::Keyframes(ref keyframes_rule) => {
let keyframes_rule = keyframes_rule.read_with(guard);
debug!("Found valid keyframes rule: {:?}", *keyframes_rule);
// Don't let a prefixed keyframes animation override a non-prefixed one.
let needs_insertion = keyframes_rule.vendor_prefix.is_none() ||
self.animations
.get(keyframes_rule.name.as_atom())
.map_or(true, |rule| rule.vendor_prefix.is_some());
if needs_insertion {
let animation = KeyframesAnimation::from_keyframes(
&keyframes_rule.keyframes,
keyframes_rule.vendor_prefix.clone(),
guard,
);
debug!("Found valid keyframe animation: {:?}", animation);
self.animations
.try_insert(keyframes_rule.name.as_atom().clone(), animation)?;
}
},
#[cfg(feature = "gecko")]
CssRule::FontFace(ref rule) => {
self.extra_data.add_font_face(rule);
},
#[cfg(feature = "gecko")]
CssRule::FontFeatureValues(ref rule) => {
self.extra_data.add_font_feature_values(rule);
},
#[cfg(feature = "gecko")]
CssRule::CounterStyle(ref rule) => {
self.extra_data.add_counter_style(guard, rule);
},
#[cfg(feature = "gecko")]
CssRule::Page(ref rule) => {
self.extra_data.add_page(rule);
},
// We don't care about any other rule.
_ => {},
}
}
Ok(())
}
/// Returns whether all the media-feature affected values matched before and
/// match now in the given stylesheet.
pub fn media_feature_affected_matches<S>(
&self,
stylesheet: &S,
guard: &SharedRwLockReadGuard,
device: &Device,
quirks_mode: QuirksMode,
) -> bool
where
S: StylesheetInDocument + 'static,
{
use crate::invalidation::media_queries::PotentiallyEffectiveMediaRules;
let effective_now = stylesheet.is_effective_for_device(device, guard);
let effective_then = self.effective_media_query_results.was_effective(stylesheet.contents());
if effective_now != effective_then {
debug!(
" > Stylesheet {:?} changed -> {}, {}",
stylesheet.media(guard),
effective_then,
effective_now
);
return false;
}
if !effective_now {
return true;
}
let mut iter = stylesheet.iter_rules::<PotentiallyEffectiveMediaRules>(device, guard);
while let Some(rule) = iter.next() {
match *rule {
CssRule::Style(..) |
CssRule::Namespace(..) |
CssRule::FontFace(..) |
CssRule::CounterStyle(..) |
CssRule::Supports(..) |
CssRule::Keyframes(..) |
CssRule::Page(..) |
CssRule::Viewport(..) |
CssRule::Document(..) |
CssRule::Layer(..) |
CssRule::FontFeatureValues(..) => {
// Not affected by device changes.
continue;
},
CssRule::Import(ref lock) => {
let import_rule = lock.read_with(guard);
let effective_now = match import_rule.stylesheet.media(guard) {
Some(m) => m.evaluate(device, quirks_mode),
None => true,
};
let effective_then = self
.effective_media_query_results
.was_effective(import_rule);
if effective_now != effective_then {
debug!(
" > @import rule {:?} changed {} -> {}",
import_rule.stylesheet.media(guard),
effective_then,
effective_now
);
return false;
}
if !effective_now {
iter.skip_children();
}
},
CssRule::Media(ref lock) => {
let media_rule = lock.read_with(guard);
let mq = media_rule.media_queries.read_with(guard);
let effective_now = mq.evaluate(device, quirks_mode);
let effective_then =
self.effective_media_query_results.was_effective(media_rule);
if effective_now != effective_then {
debug!(
" > @media rule {:?} changed {} -> {}",
mq, effective_then, effective_now
);
return false;
}
if !effective_now {
iter.skip_children();
}
},
}
}
true
}
/// Clears the cascade data, but not the invalidation data.
fn clear_cascade_data(&mut self) {
self.normal_rules.clear();
if let Some(ref mut slotted_rules) = self.slotted_rules {
slotted_rules.clear();
}
if let Some(ref mut part_rules) = self.part_rules {
part_rules.clear();
}
if let Some(ref mut host_rules) = self.host_rules {
host_rules.clear();
}
self.animations.clear();
self.extra_data.clear();
self.rules_source_order = 0;
self.num_selectors = 0;
self.num_declarations = 0;
}
fn clear(&mut self) {
self.clear_cascade_data();
self.invalidation_map.clear();
self.attribute_dependencies.clear();
self.state_dependencies = ElementState::empty();
self.document_state_dependencies = DocumentState::empty();
self.mapped_ids.clear();
self.selectors_for_cache_revalidation.clear();
self.effective_media_query_results.clear();
}
}
impl CascadeDataCacheEntry for CascadeData {
fn cascade_data(&self) -> &CascadeData {
self
}
fn rebuild<S>(
device: &Device,
quirks_mode: QuirksMode,
collection: SheetCollectionFlusher<S>,
guard: &SharedRwLockReadGuard,
old: &Self,
) -> Result<Arc<Self>, FailedAllocationError>
where
S: StylesheetInDocument + PartialEq + 'static
{
debug_assert!(collection.dirty(), "We surely need to do something?");
// If we're doing a full rebuild anyways, don't bother cloning the data.
let mut updatable_entry = match collection.data_validity() {
DataValidity::Valid | DataValidity::CascadeInvalid => old.clone(),
DataValidity::FullyInvalid => Self::new(),
};
updatable_entry.rebuild(device, quirks_mode, collection, guard)?;
Ok(Arc::new(updatable_entry))
}
#[cfg(feature = "gecko")]
fn add_size_of(&self, ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes) {
self.normal_rules.add_size_of(ops, sizes);
if let Some(ref slotted_rules) = self.slotted_rules {
slotted_rules.add_size_of(ops, sizes);
}
if let Some(ref part_rules) = self.part_rules {
part_rules.add_size_of(ops, sizes);
}
if let Some(ref host_rules) = self.host_rules {
host_rules.add_size_of(ops, sizes);
}
sizes.mInvalidationMap += self.invalidation_map.size_of(ops);
sizes.mRevalidationSelectors += self.selectors_for_cache_revalidation.size_of(ops);
sizes.mOther += self.animations.size_of(ops);
sizes.mOther += self.effective_media_query_results.size_of(ops);
sizes.mOther += self.extra_data.size_of(ops);
}
}
impl Default for CascadeData {
fn default() -> Self {
CascadeData::new()
}
}
/// A rule, that wraps a style rule, but represents a single selector of the
/// rule.
#[derive(Clone, Debug, MallocSizeOf)]
pub struct Rule {
/// The selector this struct represents. We store this and the
/// any_{important,normal} booleans inline in the Rule to avoid
/// pointer-chasing when gathering applicable declarations, which
/// can ruin performance when there are a lot of rules.
#[ignore_malloc_size_of = "CssRules have primary refs, we measure there"]
pub selector: Selector<SelectorImpl>,
/// The ancestor hashes associated with the selector.
pub hashes: AncestorHashes,
/// The source order this style rule appears in. Note that we only use
/// three bytes to store this value in ApplicableDeclarationsBlock, so
/// we could repurpose that storage here if we needed to.
pub source_order: u32,
/// The actual style rule.
#[cfg_attr(
feature = "gecko",
ignore_malloc_size_of = "Secondary ref. Primary ref is in StyleRule under Stylesheet."
)]
#[cfg_attr(feature = "servo", ignore_malloc_size_of = "Arc")]
pub style_rule: Arc<Locked<StyleRule>>,
}
impl SelectorMapEntry for Rule {
fn selector(&self) -> SelectorIter<SelectorImpl> {
self.selector.iter()
}
}
impl Rule {
/// Returns the specificity of the rule.
pub fn specificity(&self) -> u32 {
self.selector.specificity()
}
/// Turns this rule into an `ApplicableDeclarationBlock` for the given
/// cascade level.
pub fn to_applicable_declaration_block(
&self,
level: CascadeLevel,
) -> ApplicableDeclarationBlock {
let source = StyleSource::from_rule(self.style_rule.clone());
ApplicableDeclarationBlock::new(source, self.source_order, level, self.specificity())
}
/// Creates a new Rule.
pub fn new(
selector: Selector<SelectorImpl>,
hashes: AncestorHashes,
style_rule: Arc<Locked<StyleRule>>,
source_order: u32,
) -> Self {
Rule {
selector: selector,
hashes: hashes,
style_rule: style_rule,
source_order: source_order,
}
}
}
/// A function to be able to test the revalidation stuff.
pub fn needs_revalidation_for_testing(s: &Selector<SelectorImpl>) -> bool {
let mut attribute_dependencies = Default::default();
let mut mapped_ids = Default::default();
let mut state_dependencies = ElementState::empty();
let mut document_state_dependencies = DocumentState::empty();
let mut needs_revalidation = false;
let mut visitor = StylistSelectorVisitor {
passed_rightmost_selector: false,
needs_revalidation: &mut needs_revalidation,
attribute_dependencies: &mut attribute_dependencies,
state_dependencies: &mut state_dependencies,
document_state_dependencies: &mut document_state_dependencies,
mapped_ids: &mut mapped_ids,
};
s.visit(&mut visitor);
needs_revalidation
}
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