/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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 MOZILLA_LATENCY_H
#define MOZILLA_LATENCY_H

#include "mozilla/TimeStamp.h"
#include "mozilla/Logging.h"
#include "nsCOMPtr.h"
#include "nsIThread.h"
#include "mozilla/Monitor.h"
#include "nsISupportsImpl.h"
#include "nsIObserver.h"

class AsyncLatencyLogger;

mozilla::LogModule* GetLatencyLog();

// This class is a singleton. It is refcounted.
class AsyncLatencyLogger : public nsIObserver
{
  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSIOBSERVER

public:

  enum LatencyLogIndex {
    AudioMediaStreamTrack = 0,
    VideoMediaStreamTrack,
    Cubeb,
    AudioStream,
    NetEQ,
    AudioCaptureBase, // base time for capturing an audio stream
    AudioCapture, // records number of samples captured and the time
    AudioTrackInsertion, // # of samples inserted into a mediastreamtrack and the time
    MediaPipelineAudioInsertion, // Timestamp and time of timestamp
    AudioTransmit, // Timestamp and socket send time
    AudioReceive, // Timestamp and receive time
    MediaPipelineAudioPlayout, // Timestamp and playout into MST time
    MediaStreamCreate, // Source and TrackUnion streams
    AudioStreamCreate, // TrackUnion stream and AudioStream
    AudioSendRTP,
    AudioRecvRTP,
    _MAX_INDEX
  };
  // Log with a null timestamp
  void Log(LatencyLogIndex index, uint64_t aID, int64_t aValue);
  // Log with a timestamp
  void Log(LatencyLogIndex index, uint64_t aID, int64_t aValue,
           mozilla::TimeStamp &aTime);
  // Write a log message to NSPR
  void WriteLog(LatencyLogIndex index, uint64_t aID, int64_t aValue,
                mozilla::TimeStamp timestamp);
  // Get the base time used by the logger for delta calculations
  void GetStartTime(mozilla::TimeStamp &aStart);

  static AsyncLatencyLogger* Get(bool aStartTimer = false);
  static void InitializeStatics();
  // After this is called, the global log object may go away
  static void ShutdownLogger();
private:
  AsyncLatencyLogger();
  virtual ~AsyncLatencyLogger();
  int64_t GetTimeStamp();
  void Init();
  // Shut down the thread associated with this, and make sure it doesn't
  // start up again.
  void Shutdown();
  // The thread on which the IO happens
  nsCOMPtr<nsIThread> mThread;
  // This can be initialized on multiple threads, but is protected by a
  // monitor. After the initialization phase, it is accessed on the log
  // thread only.
  mozilla::TimeStamp mStart;
  // This monitor protects mStart and mMediaLatencyLog for the
  // initialization sequence. It is initialized at layout startup, and
  // destroyed at layout shutdown.
  mozilla::Mutex mMutex;
};

// Log without a time delta
void LogLatency(AsyncLatencyLogger::LatencyLogIndex index, uint64_t aID, int64_t aValue);
// Log TimeStamp::Now() (as delta)
void LogTime(AsyncLatencyLogger::LatencyLogIndex index, uint64_t aID, int64_t aValue);
// Log the specified time (as delta)
void LogTime(AsyncLatencyLogger::LatencyLogIndex index, uint64_t aID, int64_t aValue,
             mozilla::TimeStamp &aTime);

// For generating unique-ish ids for logged sources
#define LATENCY_STREAM_ID(source, trackID) \
  ((((uint64_t) (source)) & ~0x0F) | (trackID))

#endif