C++ HTMLStackItem::namespaceURI方法代码示例

void HTMLFormattingElementList::tryToEnsureNoahsArkConditionQuickly(
    HTMLStackItem* newItem,
    HeapVector<Member<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.
  HeapVector<Member<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();
    if (newItem->localName() != candidate->localName() ||
        newItem->namespaceURI() != candidate->namespaceURI())
      continue;
    if (candidate->attributes().size() != newItemAttributeCount)
      continue;

    candidates.append(candidate);
  }

  // There's room for the new element in the ark. There's no need to copy out
  // the remainingCandidates.
  if (candidates.size() < kNoahsArkCapacity)
    return;

  remainingCandidates.appendVector(candidates);
}

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());
}