/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef FrameStatistics_h_

#define FrameStatistics_h_

#include "mozilla/ReentrantMonitor.h"

namespace mozilla {

struct FrameStatisticsData

{

  // Number of frames parsed and demuxed from media.

  // Access protected by mReentrantMonitor.

  uint64_t mParsedFrames = 0;

  // Number of parsed frames which were actually decoded.

  // Access protected by mReentrantMonitor.

  uint64_t mDecodedFrames = 0;

  // Number of decoded frames which were actually sent down the rendering

  // pipeline to be painted ("presented"). Access protected by mReentrantMonitor.

  uint64_t mPresentedFrames = 0;

  // Number of frames that have been skipped because they have missed their

  // composition deadline.

  uint64_t mDroppedFrames = 0;

  // Sum of all inter-keyframe segment durations, in microseconds.

  // Dividing by count will give the average inter-keyframe time.

  uint64_t mInterKeyframeSum_us = 0;

  // Number of inter-keyframe segments summed so far.

  size_t mInterKeyframeCount = 0;

  // Maximum inter-keyframe segment duration, in microseconds.

  uint64_t mInterKeyFrameMax_us = 0;

  FrameStatisticsData() = default;

  FrameStatisticsData(uint64_t aParsed,

                      uint64_t aDecoded,

                      uint64_t aDropped,

                      uint64_t aPresented)

    : mParsedFrames(aParsed)

    , mDecodedFrames(aDecoded)

    , mPresentedFrames(aPresented)

    , mDroppedFrames(aDropped)

  {

  }

  void

  Accumulate(const FrameStatisticsData& aStats)

  {

    mParsedFrames += aStats.mParsedFrames;

    mDecodedFrames += aStats.mDecodedFrames;

    mPresentedFrames += aStats.mPresentedFrames;

    mDroppedFrames += aStats.mDroppedFrames;

    mInterKeyframeSum_us += aStats.mInterKeyframeSum_us;

    mInterKeyframeCount += aStats.mInterKeyframeCount;

    // It doesn't make sense to add max numbers, instead keep the bigger one.

    if (mInterKeyFrameMax_us < aStats.mInterKeyFrameMax_us) {

      mInterKeyFrameMax_us = aStats.mInterKeyFrameMax_us;

    }

  }

};

// Frame decoding/painting related performance counters.

// Threadsafe.

class FrameStatistics

{

public:

  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(FrameStatistics);

  FrameStatistics()

    : mReentrantMonitor("FrameStats")

  {}

  // Returns a copy of all frame statistics data.

  // Can be called on any thread.

  FrameStatisticsData GetFrameStatisticsData() const

  {

    ReentrantMonitorAutoEnter mon(mReentrantMonitor);

    return mFrameStatisticsData;

  }

  // Returns number of frames which have been parsed from the media.

  // Can be called on any thread.

  uint64_t GetParsedFrames() const

  {

    ReentrantMonitorAutoEnter mon(mReentrantMonitor);

    return mFrameStatisticsData.mParsedFrames;

  }

  // Returns the number of parsed frames which have been decoded.

  // Can be called on any thread.

  uint64_t GetDecodedFrames() const

  {

    ReentrantMonitorAutoEnter mon(mReentrantMonitor);

    return mFrameStatisticsData.mDecodedFrames;

  }

  // Returns the number of decoded frames which have been sent to the rendering

  // pipeline for painting ("presented").

  // Can be called on any thread.

  uint64_t GetPresentedFrames() const

  {

    ReentrantMonitorAutoEnter mon(mReentrantMonitor);

    return mFrameStatisticsData.mPresentedFrames;

  }

  // Returns the number of frames that have been skipped because they have

  // missed their composition deadline.

  uint64_t GetDroppedFrames() const

  {

    ReentrantMonitorAutoEnter mon(mReentrantMonitor);

    return mFrameStatisticsData.mDroppedFrames;

  }

  // Increments the parsed and decoded frame counters by the passed in counts.

  // Can be called on any thread.

  void Accumulate(const FrameStatisticsData& aStats)

  {

    ReentrantMonitorAutoEnter mon(mReentrantMonitor);

    mFrameStatisticsData.Accumulate(aStats);

  }

  // Increments the presented frame counters.

  // Can be called on any thread.

  void NotifyPresentedFrame()

  {

    ReentrantMonitorAutoEnter mon(mReentrantMonitor);

    ++mFrameStatisticsData.mPresentedFrames;

  }

  // Stack based class to assist in notifying the frame statistics of

  // parsed and decoded frames. Use inside video demux & decode functions

  // to ensure all parsed and decoded frames are reported on all return paths.

  class AutoNotifyDecoded

  {

  public:

    explicit AutoNotifyDecoded(FrameStatistics* aFrameStats)

      : mFrameStats(aFrameStats)

    {

    }

    ~AutoNotifyDecoded()

    {

      if (mFrameStats) {

        mFrameStats->Accumulate(mStats);

      }

    }

    FrameStatisticsData mStats;

  private:

    FrameStatistics* mFrameStats;

  };

private:

  ~FrameStatistics() {}

  // ReentrantMonitor to protect access of playback statistics.

  mutable ReentrantMonitor mReentrantMonitor;

  FrameStatisticsData mFrameStatisticsData;

};

} // namespace mozilla

#endif // FrameStatistics_h_