Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-08-04 21:20:23 +01:00
Code Issues Projects Releases Packages Wiki Activity

Use a 1-entry smallvec in the selector maps.

Browse source 
MozReview-Commit-ID: 1JPkVxs3cdP
This commit is contained in:
Bobby Holley 2017-08-06 10:21:49 -07:00
parent 16704bbaaa
commit 2f39213072
1 changed files with 17 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

27
components/style/selector_map.rs
View file

@ -16,7 +16,7 @@ use selector_parser::SelectorImpl;
use selectors::matching::{matches_selector, MatchingContext, ElementSelectorFlags}; use selectors::matching::{matches_selector, MatchingContext, ElementSelectorFlags};
use selectors::parser::{Component, Combinator, SelectorIter}; use selectors::parser::{Component, Combinator, SelectorIter};
use selectors::parser::LocalName as LocalNameSelector; use selectors::parser::LocalName as LocalNameSelector;
use smallvec::VecLike; use smallvec::{SmallVec, VecLike};
use std::collections::HashMap; use std::collections::HashMap;
use std::collections::hash_map; use std::collections::hash_map;
use std::hash::Hash; use std::hash::Hash;
@ -49,16 +49,21 @@ pub trait SelectorMapEntry : Sized + Clone {
/// element name, etc. will contain the Selectors that actually match that /// element name, etc. will contain the Selectors that actually match that
/// element. /// element.
/// ///
/// We use a 1-entry SmallVec to avoid a separate heap allocation in the case
/// where we only have one entry, which is quite common. See measurements in:
/// * https://bugzilla.mozilla.org/show_bug.cgi?id=1363789#c5
/// * https://bugzilla.mozilla.org/show_bug.cgi?id=681755
///
/// TODO: Tune the initial capacity of the HashMap /// TODO: Tune the initial capacity of the HashMap
#[derive(Debug)] #[derive(Debug)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))] #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
pub struct SelectorMap<T> { pub struct SelectorMap<T> {
/// A hash from an ID to rules which contain that ID selector. /// A hash from an ID to rules which contain that ID selector.
pub id_hash: MaybeCaseInsensitiveHashMap<Atom, Vec<T>>, pub id_hash: MaybeCaseInsensitiveHashMap<Atom, SmallVec<[T; 1]>>,
/// A hash from a class name to rules which contain that class selector. /// A hash from a class name to rules which contain that class selector.
pub class_hash: MaybeCaseInsensitiveHashMap<Atom, Vec<T>>, pub class_hash: MaybeCaseInsensitiveHashMap<Atom, SmallVec<[T; 1]>>,
/// A hash from local name to rules which contain that local name selector. /// A hash from local name to rules which contain that local name selector.
pub local_name_hash: FnvHashMap<LocalName, Vec<T>>, pub local_name_hash: FnvHashMap<LocalName, SmallVec<[T; 1]>>,
/// Rules that don't have ID, class, or element selectors. /// Rules that don't have ID, class, or element selectors.
pub other: Vec<T>, pub other: Vec<T>,
/// The number of entries in this map. /// The number of entries in this map.
@ -213,12 +218,12 @@ impl<T: SelectorMapEntry> SelectorMap<T> {
self.count += 1; self.count += 1;
if let Some(id_name) = get_id_name(entry.selector()) { if let Some(id_name) = get_id_name(entry.selector()) {
self.id_hash.entry(id_name, quirks_mode).or_insert_with(Vec::new).push(entry); self.id_hash.entry(id_name, quirks_mode).or_insert_with(SmallVec::new).push(entry);
return; return;
} }
if let Some(class_name) = get_class_name(entry.selector()) { if let Some(class_name) = get_class_name(entry.selector()) {
self.class_hash.entry(class_name, quirks_mode).or_insert_with(Vec::new).push(entry); self.class_hash.entry(class_name, quirks_mode).or_insert_with(SmallVec::new).push(entry);
return; return;
} }
@ -429,10 +434,12 @@ pub fn get_local_name(iter: SelectorIter<SelectorImpl>)
} }
#[inline] #[inline]
fn find_push<Str: Eq + Hash, V>(map: &mut FnvHashMap<Str, Vec<V>>, fn find_push<Str: Eq + Hash, V, VL>(map: &mut FnvHashMap<Str, VL>,
key: Str, key: Str,
value: V) { value: V)
map.entry(key).or_insert_with(Vec::new).push(value) where VL: VecLike<V> + Default
{
map.entry(key).or_insert_with(VL::default).push(value)
} }
/// Wrapper for FnvHashMap that does ASCII-case-insensitive lookup in quirks mode. /// Wrapper for FnvHashMap that does ASCII-case-insensitive lookup in quirks mode.