third_party/WebKit/Source/core/loader/PrerenderHandle.cpp

/*
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#include "core/loader/PrerenderHandle.h"

#include "core/dom/Document.h"
#include "core/frame/LocalFrame.h"
#include "core/loader/FrameLoader.h"
#include "core/loader/PrerendererClient.h"
#include "platform/Prerender.h"
#include "platform/weborigin/ReferrerPolicy.h"
#include "platform/weborigin/SecurityPolicy.h"

namespace blink {

// static
PassOwnPtrWillBeRawPtr<PrerenderHandle> PrerenderHandle::create(Document& document, PrerenderClient* client, const KURL& url, const unsigned prerenderRelTypes)
{
    // Prerenders are unlike requests in most ways (for instance, they pass down fragments, and they don't return data),
    // but they do have referrers.
    if (!document.frame())
        return nullptr;

    RefPtr<Prerender> prerender = Prerender::create(client, url, prerenderRelTypes, SecurityPolicy::generateReferrer(document.referrerPolicy(), url, document.outgoingReferrer()));

    PrerendererClient* prerendererClient = PrerendererClient::from(document.page());
    if (prerendererClient)
        prerendererClient->willAddPrerender(prerender.get());
    prerender->add();

    return adoptPtrWillBeNoop(new PrerenderHandle(document, prerender.release()));
}

PrerenderHandle::PrerenderHandle(Document& document, PassRefPtr<Prerender> prerender)
    : DocumentLifecycleObserver(&document)
    , m_prerender(prerender)
{
}

PrerenderHandle::~PrerenderHandle()
{
    if (m_prerender)
        detach();
}

void PrerenderHandle::cancel()
{
    // Avoid both abandoning and canceling the same prerender. In the abandon case, the LinkLoader cancels the
    // PrerenderHandle as the Document is destroyed, even through the DocumentLifecycleObserver has already abandoned
    // it.
    if (!m_prerender)
        return;
    m_prerender->cancel();
    detach();
}

const KURL& PrerenderHandle::url() const
{
    return m_prerender->url();
}

void PrerenderHandle::documentWasDetached()
{
#if ENABLE(OILPAN)
    // In Oilpan, a PrerenderHandle is not removed from
    // LifecycleNotifier::m_observers until a next GC is triggered.
    // Thus documentWasDetached() can be called for a PrerenderHandle
    // that is already canceled (and thus detached). In that case,
    // we should not detach the PrerenderHandle again, so we need this check.
    if (!m_prerender)
        return;
#else
    ASSERT(m_prerender);
#endif
    m_prerender->abandon();
    detach();
}

void PrerenderHandle::detach()
{
    m_prerender->removeClient();
    m_prerender.clear();
}

DEFINE_TRACE(PrerenderHandle)
{
    DocumentLifecycleObserver::trace(visitor);
}

} // namespace blink