third_party/WebKit/Source/core/dom/MutationObserverInterestGroup.cpp

/*
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#include "core/dom/MutationObserverInterestGroup.h"

#include "core/dom/MutationRecord.h"

namespace blink {

PassOwnPtrWillBeRawPtr<MutationObserverInterestGroup> MutationObserverInterestGroup::createIfNeeded(Node& target, MutationObserver::MutationType type, MutationRecordDeliveryOptions oldValueFlag, const QualifiedName* attributeName)
{
    ASSERT((type == MutationObserver::Attributes && attributeName) || !attributeName);
    WillBeHeapHashMap<RefPtrWillBeMember<MutationObserver>, MutationRecordDeliveryOptions> observers;
    target.getRegisteredMutationObserversOfType(observers, type, attributeName);
    if (observers.isEmpty())
        return nullptr;

    return adoptPtrWillBeNoop(new MutationObserverInterestGroup(observers, oldValueFlag));
}

MutationObserverInterestGroup::MutationObserverInterestGroup(WillBeHeapHashMap<RefPtrWillBeMember<MutationObserver>, MutationRecordDeliveryOptions>& observers, MutationRecordDeliveryOptions oldValueFlag)
    : m_oldValueFlag(oldValueFlag)
{
    ASSERT(!observers.isEmpty());
    m_observers.swap(observers);
}

bool MutationObserverInterestGroup::isOldValueRequested()
{
    for (auto& observer : m_observers) {
        if (hasOldValue(observer.value))
            return true;
    }
    return false;
}

void MutationObserverInterestGroup::enqueueMutationRecord(PassRefPtrWillBeRawPtr<MutationRecord> prpMutation)
{
    RefPtrWillBeRawPtr<MutationRecord> mutation = prpMutation;
    RefPtrWillBeRawPtr<MutationRecord> mutationWithNullOldValue = nullptr;
    for (auto& iter : m_observers) {
        MutationObserver* observer = iter.key.get();
        if (hasOldValue(iter.value)) {
            observer->enqueueMutationRecord(mutation);
            continue;
        }
        if (!mutationWithNullOldValue) {
            if (mutation->oldValue().isNull())
                mutationWithNullOldValue = mutation;
            else
                mutationWithNullOldValue = MutationRecord::createWithNullOldValue(mutation).get();
        }
        observer->enqueueMutationRecord(mutationWithNullOldValue);
    }
}

DEFINE_TRACE(MutationObserverInterestGroup)
{
#if ENABLE(OILPAN)
    visitor->trace(m_observers);
#endif
}

} // namespace blink