Struct style::rule_cache::RuleCache

pub struct RuleCache {
    map: FxHashMap<StrongRuleNode, SmallVec<[(CachedConditions, Arc<ComputedValues>); 1]>>,
}

A TLS cache from rules matched to computed values.

Fields

map: FxHashMap<StrongRuleNode, SmallVec<[(CachedConditions, Arc<ComputedValues>); 1]>>

Implementations

impl RuleCache

pub fn new() -> Self

Creates an empty RuleCache.

fn get_rule_node_for_cache<'r>( guards: &StylesheetGuards<'_>, rule_node: Option<&'r StrongRuleNode>, ) -> Option<&'r StrongRuleNode>

Walk the rule tree and return a rule node for using as the key for rule cache.

It currently skips animation / style attribute / preshint rules when they don’t contain any declaration of a reset property. We don’t skip other levels because walking the whole parent chain can be expensive.

TODO(emilio): Measure this, this was not super-well measured for performance (this was done for memory in bug 1427681)… Walking the rule tree might be worth it if we hit the cache enough?

pub fn find( &self, guards: &StylesheetGuards<'_>, builder_with_early_props: &StyleBuilder<'_>, ) -> Option<&ComputedValues>

Finds a node in the properties matched cache.

This needs to receive a StyleBuilder with the early properties already applied.

pub fn insert_if_possible( &mut self, guards: &StylesheetGuards<'_>, style: &Arc<ComputedValues>, pseudo: Option<&PseudoElement>, conditions: &RuleCacheConditions, ) -> bool

Inserts a node into the rules cache if possible.

Returns whether the style was inserted into the cache.