third_party/WebKit/Source/core/dom/custom/V0CustomElementProcessingStack.cpp

/*
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 * modification, are permitted provided that the following conditions
 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#include "core/dom/custom/V0CustomElementProcessingStack.h"

#include "core/dom/custom/V0CustomElementCallbackQueue.h"
#include "core/dom/custom/V0CustomElementScheduler.h"

namespace blink {

size_t V0CustomElementProcessingStack::s_elementQueueStart = 0;

// The base of the stack has a null sentinel value.
size_t V0CustomElementProcessingStack::s_elementQueueEnd = kNumSentinels;

V0CustomElementProcessingStack& V0CustomElementProcessingStack::instance()
{
    DEFINE_STATIC_LOCAL(V0CustomElementProcessingStack, instance, (new V0CustomElementProcessingStack));
    return instance;
}

// Dispatches callbacks when popping the processing stack.
void V0CustomElementProcessingStack::processElementQueueAndPop()
{
    instance().processElementQueueAndPop(s_elementQueueStart, s_elementQueueEnd);
}

void V0CustomElementProcessingStack::processElementQueueAndPop(size_t start, size_t end)
{
    DCHECK(isMainThread());
    V0CustomElementCallbackQueue::ElementQueueId thisQueue = currentElementQueue();

    for (size_t i = start; i < end; ++i) {
        {
            // The created callback may schedule entered document
            // callbacks.
            CallbackDeliveryScope deliveryScope;
            m_flattenedProcessingStack[i]->processInElementQueue(thisQueue);
        }

        DCHECK_EQ(start, s_elementQueueStart);
        DCHECK_EQ(end, s_elementQueueEnd);
    }

    // Pop the element queue from the processing stack
    m_flattenedProcessingStack.resize(start);
    s_elementQueueEnd = start;

    if (s_elementQueueStart == kNumSentinels)
        V0CustomElementScheduler::callbackDispatcherDidFinish();
}

void V0CustomElementProcessingStack::enqueue(V0CustomElementCallbackQueue* callbackQueue)
{
    DCHECK(inCallbackDeliveryScope());

    if (callbackQueue->owner() == currentElementQueue())
        return;

    callbackQueue->setOwner(currentElementQueue());

    m_flattenedProcessingStack.append(callbackQueue);
    ++s_elementQueueEnd;
}

DEFINE_TRACE(V0CustomElementProcessingStack)
{
    visitor->trace(m_flattenedProcessingStack);
}

} // namespace blink