ProbingEstimator: Erase history based on time threshold

webrtc/modules/congestion_controller/probe_bitrate_estimator.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_CONGESTION_CONTROLLER_PROBE_BITRATE_ESTIMATOR_H_
 #define WEBRTC_MODULES_CONGESTION_CONTROLLER_PROBE_BITRATE_ESTIMATOR_H_
 
 #include <map>
 #include <limits>
 
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 
 namespace webrtc {
 
-struct ProbingResult {
-  static constexpr int kNoEstimate = -1;
-
-  ProbingResult();
-  ProbingResult(int bps, int64_t timestamp);
-  bool valid() const;
-
-  int bps;
-  int64_t timestamp;
-};
-
 class ProbeBitrateEstimator {
  public:
   ProbeBitrateEstimator();
 
-  // Should be called for every packet we receive feedback about. If the
-  // packet was used for probing it will validate/calculate the resulting
-  // bitrate and return the result.
-  ProbingResult PacketFeedback(const PacketInfo& packet_info);
+  // Should be called for every probe packet we receive feedback about.
+  // Returns the estimated bitrate if the probe completes a valid cluster.
+  int HandleProbeAndEstimateBitrate(const PacketInfo& packet_info);
 
  private:
   struct AggregatedCluster {
     int num_probes = 0;
     int64_t first_send_ms = std::numeric_limits<int64_t>::max();
     int64_t last_send_ms = 0;
     int64_t first_receive_ms = std::numeric_limits<int64_t>::max();
     int64_t last_receive_ms = 0;
     size_t size = 0;
   };
 
+  // Erases old cluster data that was seen before |timestamp_ms|.
+  void EraseOldClusters(int64_t timestamp_ms);
+
   std::map<int, AggregatedCluster> clusters_;
-  int last_valid_cluster_id_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_CONGESTION_CONTROLLER_PROBE_BITRATE_ESTIMATOR_H_