void HTMLFormattingElementList::tryToEnsureNoahsArkConditionQuickly(HTMLStackItem* newItem, Vector<HTMLStackItem*>& remainingCandidates)
{
ASSERT(remainingCandidates.isEmpty());
if (m_entries.size() < kNoahsArkCapacity)
return;
// Use a vector with inline capacity to avoid a malloc in the common case
// of a quickly ensuring the condition.
Vector<HTMLStackItem*, 10> candidates;
size_t newItemAttributeCount = newItem->attributes().size();
for (size_t i = m_entries.size(); i; ) {
--i;
Entry& entry = m_entries[i];
if (entry.isMarker())
break;
// Quickly reject obviously non-matching candidates.
HTMLStackItem* candidate = entry.stackItem().get();
if (newItem->localName() != candidate->localName() || newItem->namespaceURI() != candidate->namespaceURI())
continue;
if (candidate->attributes().size() != newItemAttributeCount)
continue;
candidates.append(candidate);
}
if (candidates.size() < kNoahsArkCapacity)
return; // There's room for the new element in the ark. There's no need to copy out the remainingCandidates.
remainingCandidates.append(candidates);
}
// http://www.whatwg.org/specs/web-apps/current-work/multipage/tree-construction.html#mathml-text-integration-point
bool HTMLElementStack::isMathMLTextIntegrationPoint(HTMLStackItem& item)
{
return item.hasTagName(MathMLNames::miTag)
|| item.hasTagName(MathMLNames::moTag)
|| item.hasTagName(MathMLNames::mnTag)
|| item.hasTagName(MathMLNames::msTag)
|| item.hasTagName(MathMLNames::mtextTag);
}
bool HTMLElementStack::inScope(Element* targetElement) const {
for (ElementRecord* pos = m_top.get(); pos; pos = pos->next()) {
HTMLStackItem* item = pos->stackItem();
if (item->node() == targetElement)
return true;
if (isScopeMarker(item))
return false;
}
ASSERT_NOT_REACHED(); // <html> is always on the stack and is a scope marker.
return false;
}
bool HTMLElementStack::hasNumberedHeaderElementInScope() const {
for (ElementRecord* record = m_top.get(); record; record = record->next()) {
HTMLStackItem* item = record->stackItem();
if (item->isNumberedHeaderElement())
return true;
if (isScopeMarker(item))
return false;
}
ASSERT_NOT_REACHED(); // <html> is always on the stack and is a scope marker.
return false;
}
bool inScopeCommon(HTMLElementStack::ElementRecord* top, const AtomicString& targetTag)
{
for (HTMLElementStack::ElementRecord* pos = top; pos; pos = pos->next()) {
HTMLStackItem* item = pos->stackItem().get();
if (item->matchesHTMLTag(targetTag))
return true;
if (isMarker(item))
return false;
}
ASSERT_NOT_REACHED(); // <html> is always on the stack and is a scope marker.
return false;
}
// http://www.whatwg.org/specs/web-apps/current-work/multipage/tree-construction.html#html-integration-point
bool HTMLElementStack::isHTMLIntegrationPoint(HTMLStackItem& item)
{
if (item.hasTagName(MathMLNames::annotation_xmlTag)) {
const Attribute* encodingAttr = item.findAttribute(MathMLNames::encodingAttr);
if (encodingAttr) {
const String& encoding = encodingAttr->value();
return equalLettersIgnoringASCIICase(encoding, "text/html")
|| equalLettersIgnoringASCIICase(encoding, "application/xhtml+xml");
}
return false;
}
return item.hasTagName(SVGNames::foreignObjectTag)
|| item.hasTagName(SVGNames::descTag)
|| item.hasTagName(SVGNames::titleTag);
}
void HTMLFormattingElementList::ensureNoahsArkCondition(HTMLStackItem* newItem)
{
Vector<HTMLStackItem*> candidates;
tryToEnsureNoahsArkConditionQuickly(newItem, candidates);
if (candidates.isEmpty())
return;
// We pre-allocate and re-use this second vector to save one malloc per
// attribute that we verify.
Vector<HTMLStackItem*> remainingCandidates;
remainingCandidates.reserveInitialCapacity(candidates.size());
const Vector<Attribute>& attributes = newItem->attributes();
for (size_t i = 0; i < attributes.size(); ++i) {
const Attribute& attribute = attributes[i];
for (size_t j = 0; j < candidates.size(); ++j) {
HTMLStackItem* candidate = candidates[j];
// These properties should already have been checked by tryToEnsureNoahsArkConditionQuickly.
ASSERT(newItem->attributes().size() == candidate->attributes().size());
ASSERT(newItem->localName() == candidate->localName() && newItem->namespaceURI() == candidate->namespaceURI());
Attribute* candidateAttribute = candidate->getAttributeItem(attribute.name());
if (candidateAttribute && candidateAttribute->value() == attribute.value())
remainingCandidates.append(candidate);
}
if (remainingCandidates.size() < kNoahsArkCapacity)
return;
candidates.swap(remainingCandidates);
remainingCandidates.shrink(0);
}
// Inductively, we shouldn't spin this loop very many times. It's possible,
// however, that we wil spin the loop more than once because of how the
// formatting element list gets permuted.
for (size_t i = kNoahsArkCapacity - 1; i < candidates.size(); ++i)
remove(candidates[i]->element());
}
