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Remove one level of nesting in Stylist
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Since #13134, the "normal" and "important" parts of `Stylist` are identical,
so we don’t need to store them twice.
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@SimonSapin
SimonSapin committed Sep 6, 2016
1 parent 3ce64fd commit 74eaf2a
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Showing 2 changed files with 104 additions and 116 deletions.
188 changes: 87 additions & 101 deletions components/style/selector_matching.rs
View file
Expand Up @@ -38,8 +38,7 @@ pub type FnvHashMap<K, V> = HashMap<K, V, BuildHasherDefault<::fnv::FnvHasher>>;
/// for a given document. The selectors are converted into `Rule`s
/// (defined in rust-selectors), and introduced in a `SelectorMap`
/// depending on the pseudo-element (see `PerPseudoElementSelectorMap`),
/// stylesheet origin (see `PerOriginSelectorMap`), and priority
/// (see the `normal` and `important` fields in `PerOriginSelectorMap`).
/// and stylesheet origin (see the fields of `PerPseudoElementSelectorMap`).
///
/// This structure is effectively created once per pipeline, in the
/// LayoutThread corresponding to that pipeline.
Expand Down Expand Up @@ -162,38 +161,26 @@ impl Stylist {
}
let mut rules_source_order = self.rules_source_order;

// Take apart the StyleRule into individual Rules and insert
// them into the SelectorMap of that priority.
macro_rules! append(
($style_rule: ident, $priority: ident, $importance: expr) => {
for selector in &$style_rule.selectors {
let map = if let Some(ref pseudo) = selector.pseudo_element {
self.pseudos_map
.entry(pseudo.clone())
.or_insert_with(PerPseudoElementSelectorMap::new)
.borrow_for_origin(&stylesheet.origin)
} else {
self.element_map.borrow_for_origin(&stylesheet.origin)
};

map.$priority.insert(Rule {
selector: selector.complex_selector.clone(),
declarations: ApplicableDeclarationBlock {
specificity: selector.specificity,
mixed_declarations: $style_rule.declarations.clone(),
importance: $importance,
source_order: rules_source_order,
},
});
}
};
);

for rule in stylesheet.effective_rules(&self.device) {
match *rule {
CSSRule::Style(ref style_rule) => {
append!(style_rule, normal, Importance::Normal);
append!(style_rule, important, Importance::Important);
for selector in &style_rule.selectors {
let map = if let Some(ref pseudo) = selector.pseudo_element {
self.pseudos_map
.entry(pseudo.clone())
.or_insert_with(PerPseudoElementSelectorMap::new)
.borrow_for_origin(&stylesheet.origin)
} else {
self.element_map.borrow_for_origin(&stylesheet.origin)
};

map.insert(Rule {
selector: selector.complex_selector.clone(),
declarations: style_rule.declarations.clone(),
specificity: selector.specificity,
source_order: rules_source_order,
});
}
rules_source_order += 1;

for selector in &style_rule.selectors {
Expand Down Expand Up @@ -242,8 +229,7 @@ impl Stylist {
if let Some(map) = self.pseudos_map.remove(&pseudo) {
let mut declarations = vec![];

map.user_agent.normal.get_universal_rules(&mut declarations);
map.user_agent.important.get_universal_rules(&mut declarations);
map.user_agent.get_universal_rules(&mut declarations);

self.precomputed_pseudo_element_decls.insert(pseudo, declarations);
}
Expand Down Expand Up @@ -368,12 +354,12 @@ impl Stylist {

debug!("Determining if style is shareable: pseudo: {}", pseudo_element.is_some());
// Step 1: Normal user-agent rules.
map.user_agent.normal.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Normal);
map.user_agent.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Normal);
debug!("UA normal: {:?}", relations);

// Step 2: Presentational hints.
Expand All @@ -386,19 +372,19 @@ impl Stylist {
debug!("preshints: {:?}", relations);

// Step 3: User and author normal rules.
map.user.normal.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Normal);
map.user.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Normal);
debug!("user normal: {:?}", relations);
map.author.normal.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Normal);
map.author.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Normal);
debug!("author normal: {:?}", relations);

// Step 4: Normal style attributes.
Expand All @@ -414,12 +400,12 @@ impl Stylist {
debug!("style attr: {:?}", relations);

// Step 5: Author-supplied `!important` rules.
map.author.important.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Important);
map.author.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Important);

debug!("author important: {:?}", relations);

Expand All @@ -436,21 +422,21 @@ impl Stylist {
debug!("style attr important: {:?}", relations);

// Step 7: User and UA `!important` rules.
map.user.important.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Important);
map.user.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Important);

debug!("user important: {:?}", relations);

map.user_agent.important.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Important);
map.user_agent.get_all_matching_rules(element,
parent_bf,
applicable_declarations,
&mut relations,
reason,
Importance::Important);

debug!("UA important: {:?}", relations);

Expand Down Expand Up @@ -549,51 +535,30 @@ impl Stylist {
}


/// Map that contains the CSS rules for a given origin.
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
struct PerOriginSelectorMap {
/// Rules that contains at least one property declaration with
/// normal importance.
normal: SelectorMap,
/// Rules that contains at least one property declaration with
/// !important.
important: SelectorMap,
}

impl PerOriginSelectorMap {
#[inline]
fn new() -> Self {
PerOriginSelectorMap {
normal: SelectorMap::new(),
important: SelectorMap::new(),
}
}
}

/// Map that contains the CSS rules for a specific PseudoElement
/// (or lack of PseudoElement).
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
struct PerPseudoElementSelectorMap {
/// Rules from user agent stylesheets
user_agent: PerOriginSelectorMap,
user_agent: SelectorMap,
/// Rules from author stylesheets
author: PerOriginSelectorMap,
author: SelectorMap,
/// Rules from user stylesheets
user: PerOriginSelectorMap,
user: SelectorMap,
}

impl PerPseudoElementSelectorMap {
#[inline]
fn new() -> Self {
PerPseudoElementSelectorMap {
user_agent: PerOriginSelectorMap::new(),
author: PerOriginSelectorMap::new(),
user: PerOriginSelectorMap::new(),
user_agent: SelectorMap::new(),
author: SelectorMap::new(),
user: SelectorMap::new(),
}
}

#[inline]
fn borrow_for_origin(&mut self, origin: &Origin) -> &mut PerOriginSelectorMap {
fn borrow_for_origin(&mut self, origin: &Origin) -> &mut SelectorMap {
match *origin {
Origin::UserAgent => &mut self.user_agent,
Origin::Author => &mut self.author,
Expand Down Expand Up @@ -737,7 +702,14 @@ impl SelectorMap {
for rule in self.other_rules.iter() {
if rule.selector.compound_selector.is_empty() &&
rule.selector.next.is_none() {
matching_rules_list.push(rule.declarations.clone());
if rule.declarations.any_normal() {
matching_rules_list.push(
rule.to_applicable_declaration_block(Importance::Normal));
}
if rule.declarations.any_important() {
matching_rules_list.push(
rule.to_applicable_declaration_block(Importance::Important));
}
}
}

Expand Down Expand Up @@ -782,7 +754,7 @@ impl SelectorMap {
V: VecLike<ApplicableDeclarationBlock>
{
for rule in rules.iter() {
let block = &rule.declarations.mixed_declarations;
let block = &rule.declarations;
let any_declaration_for_importance = if importance.important() {
block.any_important()
} else {
Expand All @@ -791,7 +763,7 @@ impl SelectorMap {
if any_declaration_for_importance &&
matches_complex_selector(&*rule.selector, element, parent_bf,
relations, reason) {
matching_rules.push(rule.declarations.clone());
matching_rules.push(rule.to_applicable_declaration_block(importance));
}
}
}
Expand Down Expand Up @@ -868,7 +840,21 @@ pub struct Rule {
// that it matches. Selector contains an owned vector (through
// ComplexSelector) and we want to avoid the allocation.
pub selector: Arc<ComplexSelector<TheSelectorImpl>>,
pub declarations: ApplicableDeclarationBlock,
pub declarations: Arc<PropertyDeclarationBlock>,
pub source_order: usize,
pub specificity: u32,
}

impl Rule {
fn to_applicable_declaration_block(&self, importance: Importance)
-> ApplicableDeclarationBlock {
ApplicableDeclarationBlock {
mixed_declarations: self.declarations.clone(),
importance: importance,
source_order: self.source_order,
specificity: self.specificity,
}
}
}

/// A property declaration together with its precedence among rules of equal specificity so that
Expand Down
32 changes: 17 additions & 15 deletions tests/unit/style/selector_matching.rs
View file
Expand Up @@ -6,8 +6,9 @@ use cssparser::Parser;
use selectors::parser::{LocalName, ParserContext, parse_selector_list};
use std::sync::Arc;
use string_cache::Atom;
use style::properties::{Importance, PropertyDeclarationBlock};
use style::selector_matching::{ApplicableDeclarationBlock, Rule, SelectorMap};
use style::properties::{PropertyDeclarationBlock, PropertyDeclaration, DeclaredValue};
use style::properties::{longhands, Importance};
use style::selector_matching::{Rule, SelectorMap};

/// Helper method to get some Rules from selector strings.
/// Each sublist of the result contains the Rules for one StyleRule.
Expand All @@ -18,15 +19,16 @@ fn get_mock_rules(css_selectors: &[&str]) -> Vec<Vec<Rule>> {
.unwrap().into_iter().map(|s| {
Rule {
selector: s.complex_selector.clone(),
declarations: ApplicableDeclarationBlock {
mixed_declarations: Arc::new(PropertyDeclarationBlock {
declarations: Vec::new(),
important_count: 0,
}),
importance: Importance::Normal,
specificity: s.specificity,
source_order: i,
}
declarations: Arc::new(PropertyDeclarationBlock {
declarations: vec![
(PropertyDeclaration::Display(DeclaredValue::Value(
longhands::display::SpecifiedValue::block)),
Importance::Normal),
],
important_count: 0,
}),
specificity: s.specificity,
source_order: i,
}
}).collect()
}).collect()
Expand All @@ -48,8 +50,8 @@ fn get_mock_map(selectors: &[&str]) -> SelectorMap {
#[test]
fn test_rule_ordering_same_specificity() {
let rules_list = get_mock_rules(&["a.intro", "img.sidebar"]);
let a = &rules_list[0][0].declarations;
let b = &rules_list[1][0].declarations;
let a = &rules_list[0][0];
let b = &rules_list[1][0];
assert!((a.specificity, a.source_order) < ((b.specificity, b.source_order)),
"The rule that comes later should win.");
}
Expand Down Expand Up @@ -89,9 +91,9 @@ fn test_insert() {
let rules_list = get_mock_rules(&[".intro.foo", "#top"]);
let mut selector_map = SelectorMap::new();
selector_map.insert(rules_list[1][0].clone());
assert_eq!(1, selector_map.id_hash.get(&atom!("top")).unwrap()[0].declarations.source_order);
assert_eq!(1, selector_map.id_hash.get(&atom!("top")).unwrap()[0].source_order);
selector_map.insert(rules_list[0][0].clone());
assert_eq!(0, selector_map.class_hash.get(&Atom::from("intro")).unwrap()[0].declarations.source_order);
assert_eq!(0, selector_map.class_hash.get(&Atom::from("intro")).unwrap()[0].source_order);
assert!(selector_map.class_hash.get(&Atom::from("foo")).is_none());
}

Expand Down

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