/*

* Copyright (C) 2018-2019 Apple Inc. All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

*

* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''

* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS

* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

* THE POSSIBILITY OF SUCH DAMAGE.

*/

#pragma once

#if HAVE(CVDISPLAYLINK)

#include "Connection.h"

#include "DisplayLinkObserverID.h"

#include <CoreVideo/CVDisplayLink.h>

#include <WebCore/AnimationFrameRate.h>

#include <WebCore/DisplayUpdate.h>

#include <WebCore/PlatformScreen.h>

#include <wtf/HashMap.h>

#include <wtf/Lock.h>

namespace IPC {

class Connection;

}

namespace WebKit {

class DisplayLink {

WTF_MAKE_FAST_ALLOCATED;

public:

explicit DisplayLink(WebCore::PlatformDisplayID);

~DisplayLink();

void addObserver(IPC::Connection&, DisplayLinkObserverID, WebCore::FramesPerSecond);

void removeObserver(IPC::Connection&, DisplayLinkObserverID);

void removeObservers(IPC::Connection&);

void incrementFullSpeedRequestClientCount(IPC::Connection&);

void decrementFullSpeedRequestClientCount(IPC::Connection&);

void setPreferredFramesPerSecond(IPC::Connection&, DisplayLinkObserverID, WebCore::FramesPerSecond);

WebCore::PlatformDisplayID displayID() const { return m_displayID; }

WebCore::FramesPerSecond nominalFramesPerSecond() const { return m_displayNominalFramesPerSecond; }

// When responsiveness is critical, we send the IPC to a background queue. Otherwise, we send it to the

// main thread to avoid unnecessary thread hopping and save power.

static void setShouldSendIPCOnBackgroundQueue(bool value) { shouldSendIPCOnBackgroundQueue = value; }

private:

static CVReturn displayLinkCallback(CVDisplayLinkRef, const CVTimeStamp*, const CVTimeStamp*, CVOptionFlags, CVOptionFlags*, void* data);

void notifyObserversDisplayWasRefreshed();

void removeInfoForConnectionIfPossible(IPC::Connection&) WTF_REQUIRES_LOCK(m_observersLock);

static WebCore::FramesPerSecond nominalFramesPerSecondFromDisplayLink(CVDisplayLinkRef);

struct ObserverInfo {

DisplayLinkObserverID observerID;

WebCore::FramesPerSecond preferredFramesPerSecond;

};

struct ConnectionClientInfo {

unsigned fullSpeedUpdatesClientCount { 0 };

Vector<ObserverInfo> observers;

};

CVDisplayLinkRef m_displayLink { nullptr };

Lock m_observersLock;

HashMap<IPC::Connection::UniqueID, ConnectionClientInfo> m_observers WTF_GUARDED_BY_LOCK(m_observersLock);

WebCore::PlatformDisplayID m_displayID;

WebCore::FramesPerSecond m_displayNominalFramesPerSecond { 0 };

WebCore::DisplayUpdate m_currentUpdate;

unsigned m_fireCountWithoutObservers { 0 };

static bool shouldSendIPCOnBackgroundQueue;

};

} // namespace WebKit

#endif // HAVE(CVDISPLAYLINK)