void SelectorFilter::collectIdentifierHashes(const CSSSelector& selector,
unsigned* identifierHashes,
unsigned maximumIdentifierCount) {
unsigned* hash = identifierHashes;
unsigned* end = identifierHashes + maximumIdentifierCount;
CSSSelector::RelationType relation = selector.relation();
if (selector.relationIsAffectedByPseudoContent()) {
// Disable fastRejectSelector.
*identifierHashes = 0;
return;
}
// Skip the topmost selector. It is handled quickly by the rule hashes.
bool skipOverSubselectors = true;
for (const CSSSelector* current = selector.tagHistory(); current;
current = current->tagHistory()) {
// Only collect identifiers that match ancestors.
switch (relation) {
case CSSSelector::SubSelector:
if (!skipOverSubselectors)
collectDescendantSelectorIdentifierHashes(*current, hash);
break;
case CSSSelector::DirectAdjacent:
case CSSSelector::IndirectAdjacent:
skipOverSubselectors = true;
break;
case CSSSelector::ShadowSlot:
// Disable fastRejectSelector.
*identifierHashes = 0;
return;
case CSSSelector::Descendant:
case CSSSelector::Child:
// Fall through.
case CSSSelector::ShadowPseudo:
case CSSSelector::ShadowDeep:
skipOverSubselectors = false;
collectDescendantSelectorIdentifierHashes(*current, hash);
break;
}
if (hash == end)
return;
relation = current->relation();
if (current->relationIsAffectedByPseudoContent()) {
// Disable fastRejectSelector.
*identifierHashes = 0;
return;
}
}
*hash = 0;
}
bool operator()(const CSSSelector& selector)
{
return selector.relationIsAffectedByPseudoContent();
}