More reliable ALR detection

webrtc/modules/pacing/alr_detector.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_PACING_ALR_DETECTOR_H_
 #define WEBRTC_MODULES_PACING_ALR_DETECTOR_H_
 
+#include "webrtc/base/rate_statistics.h"
 #include "webrtc/common_types.h"
 #include "webrtc/modules/pacing/paced_sender.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 // Application limited region detector is a class that utilizes signals of
 // elapsed time and bytes sent to estimate whether network traffic is
 // currently limited by the application's ability to generate traffic.
 //
 // AlrDetector provides a signal that can be utilized to adjust
 // estimate bandwidth.
 // Note: This class is not thread-safe.
 class AlrDetector {
  public:
   AlrDetector();
   ~AlrDetector();
-  void OnBytesSent(size_t bytes_sent, int64_t elapsed_time_ms);
+
+  void OnBytesSent(size_t bytes_sent, int64_t now_ms);
+
   // Set current estimated bandwidth.
   void SetEstimatedBitrate(int bitrate_bps);
+
   // Returns true if currently in application-limited region.
   bool InApplicationLimitedRegion();
 
  private:
-  size_t measurement_interval_bytes_sent_;
-  int64_t measurement_interval_elapsed_time_ms_;
-  int estimated_bitrate_bps_;
-  // Number of consecutive periods over which we observe traffic is application
-  // limited.
-  int application_limited_count_;
+  RateStatistics rate_;
+  int estimated_bitrate_bps_ = 0;
+  bool application_limited_ = false;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_PACING_ALR_DETECTOR_H_