Cast logging: Additional stats for getStats() API.

media/cast/logging/receiver_time_offset_estimator_impl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_CAST_LOGGING_RECEIVER_TIME_OFFSET_ESTIMATOR_IMPL_H_
 #define MEDIA_CAST_LOGGING_RECEIVER_TIME_OFFSET_ESTIMATOR_IMPL_H_
 
 #include "base/time/time.h"
 #include "base/threading/thread_checker.h"
 #include "media/cast/logging/logging_defines.h"
 #include "media/cast/logging/receiver_time_offset_estimator.h"
 
+namespace base {
+class TickClock;
+}
+
 namespace media {
 namespace cast {
 
 // This implementation listens to three types of video events:
 // 1. FRAME_ENCODED (sender side)
 // 2. FRAME_ACK_SENT (receiver side)
 // 3. FRAME_ACK_RECEIVED (sender side)
 // There is a causal relationship between these events in that these events
 // must happen in order. This class obtains the lower and upper bounds for
 // the offset by taking the difference of timestamps (2) - (1) and (2) - (3),
 // respectively.
 // The bound will become better as the latency between the events decreases.
 class ReceiverTimeOffsetEstimatorImpl : public ReceiverTimeOffsetEstimator {
  public:
-  ReceiverTimeOffsetEstimatorImpl();
+  ReceiverTimeOffsetEstimatorImpl(base::TickClock* clock);
 
   virtual ~ReceiverTimeOffsetEstimatorImpl();
 
   // RawEventSubscriber implementations.
   virtual void OnReceiveFrameEvent(const FrameEvent& frame_event) OVERRIDE;
   virtual void OnReceivePacketEvent(const PacketEvent& packet_event) OVERRIDE;
 
   // ReceiverTimeOffsetEstimator implementation.
   virtual bool GetReceiverOffsetBounds(base::TimeDelta* lower_bound,
                                        base::TimeDelta* upper_bound) OVERRIDE;
 
  private:
   struct EventTimes {
     base::TimeTicks event_a_time;
     base::TimeTicks event_b_time;
     base::TimeTicks event_c_time;
   };
 
   typedef std::map<RtpTimestamp, EventTimes> EventTimesMap;
 
   void UpdateOffsetBounds(const EventTimes& event);
 
   // Fixed size storage to store event times for recent frames.
   EventTimesMap event_times_map_;
 
   bool bounded_;
+  base::TickClock* clock_;  // Not owned by this class.
+
+  bool offset_bounds_valid_;
   base::TimeDelta offset_lower_bound_;
   base::TimeDelta offset_upper_bound_;
+  base::TimeDelta prev_offset_lower_bound_;
+  base::TimeDelta prev_offset_upper_bound_;
+  base::TimeTicks last_reset_time_;
 
   base::ThreadChecker thread_checker_;
   DISALLOW_COPY_AND_ASSIGN(ReceiverTimeOffsetEstimatorImpl);
 };
 
 }  // namespace cast
 }  // namespace media
 
 #endif  // MEDIA_CAST_LOGGING_RECEIVER_TIME_OFFSET_ESTIMATOR_IMPL_H_