std::pair<const CSSSelector*, RuleFeatureSet::UseFeaturesType>
RuleFeatureSet::extractInvalidationSetFeatures(const CSSSelector& selector, InvalidationSetFeatures& features, PositionType position, CSSSelector::PseudoType pseudo)
{
bool foundFeatures = false;
for (const CSSSelector* current = &selector; current; current = current->tagHistory()) {
if (pseudo != CSSSelector::PseudoNot)
foundFeatures |= extractInvalidationSetFeature(*current, features);
// Initialize the entry in the invalidation set map, if supported.
if (InvalidationSet* invalidationSet = invalidationSetForSelector(*current, InvalidateDescendants)) {
if (position == Subject)
invalidationSet->setInvalidatesSelf();
} else {
if (requiresSubtreeInvalidation(*current)) {
// Fall back to use subtree invalidations, even for features in the
// rightmost compound selector. Returning the start &selector here
// will make addFeaturesToInvalidationSets start marking invalidation
// sets for subtree recalc for features in the rightmost compound
// selector.
return std::make_pair(&selector, ForceSubtree);
}
if (const CSSSelectorList* selectorList = current->selectorList()) {
ASSERT(supportsInvalidationWithSelectorList(current->pseudoType()));
const CSSSelector* subSelector = selectorList->first();
bool allSubSelectorsHaveFeatures = !!subSelector;
for (; subSelector; subSelector = CSSSelectorList::next(*subSelector)) {
auto result = extractInvalidationSetFeatures(*subSelector, features, position, current->pseudoType());
if (result.first) {
// A non-null selector return means the sub-selector contained a
// selector which requiresSubtreeInvalidation(). Return the rightmost
// selector to mark for subtree recalcs like above.
return std::make_pair(&selector, ForceSubtree);
}
allSubSelectorsHaveFeatures &= result.second == UseFeatures;
}
foundFeatures |= allSubSelectorsHaveFeatures;
}
}
if (current->relation() == CSSSelector::SubSelector)
continue;
features.treeBoundaryCrossing = current->isShadowSelector();
features.adjacent = current->isAdjacentSelector();
if (current->relation() == CSSSelector::DirectAdjacent)
features.maxDirectAdjacentSelectors = 1;
return std::make_pair(current->tagHistory(), foundFeatures ? UseFeatures : ForceSubtree);
}
return std::make_pair(nullptr, foundFeatures ? UseFeatures : ForceSubtree);
}
const CSSSelector* RuleFeatureSet::extractInvalidationSetFeatures(const CSSSelector& selector, InvalidationSetFeatures& features)
{
const CSSSelector* lastSelector = &selector;
for (; lastSelector; lastSelector = lastSelector->tagHistory()) {
extractInvalidationSetFeature(*lastSelector, features);
// Initialize the entry in the invalidation set map, if supported.
invalidationSetForSelector(*lastSelector);
if (lastSelector->pseudoType() == CSSSelector::PseudoHost || lastSelector->pseudoType() == CSSSelector::PseudoAny) {
if (const CSSSelectorList* selectorList = lastSelector->selectorList()) {
for (const CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(*selector))
extractInvalidationSetFeatures(*selector, features);
}
}
if (lastSelector->relation() != CSSSelector::SubSelector)
break;
}
return lastSelector;
}
