BitrateProber: Support higher probing bitrates

webrtc/modules/pacing/bitrate_prober.h

 /*
  *  Copyright (c) 2014 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.
  */
 
@@ skipping 18 matching lines @@
   // Returns true if the prober is in a probing session, i.e., it currently
   // wants packets to be sent out according to the time returned by
   // TimeUntilNextProbe().
   bool IsProbing() const;
 
   // Initializes a new probing session if the prober is allowed to probe. Does
   // not initialize the prober unless the packet size is large enough to probe
   // with.
   void OnIncomingPacket(size_t packet_size);
 
-  // Create a cluster used to probe for |bitrate_bps| with |num_packets| number
-  // of packets.
-  void CreateProbeCluster(int bitrate_bps, int num_packets);
+  // Create a cluster used to probe for |bitrate_bps| with |num_probes| number
+  // of probes.
+  void CreateProbeCluster(int bitrate_bps, int num_probes);
 
-  // Returns the number of milliseconds until the next packet should be sent to
+  // Returns the number of milliseconds until the next probe should be sent to
   // get accurate probing.
   int TimeUntilNextProbe(int64_t now_ms);
 
   // Which cluster that is currently being used for probing.
   int CurrentClusterId() const;
 
-  // Returns the number of bytes that the prober recommends for the next probe
-  // packet.
-  size_t RecommendedPacketSize() const;
+  // Returns the number of bytes that the prober recommends for the next probe.
+  size_t RecommendedProbeSize() const;
 
-  // Called to report to the prober that a packet has been sent, which helps the
-  // prober know when to move to the next packet in a probe.
-  void PacketSent(int64_t now_ms, size_t packet_size);
+  // Called to report to the prober that a probe has been sent. In case of
+  // multiple packets per probe, this call would be made at the end of sending
+  // the last packet in probe. |probe_size| is the total size of all packets
+  // in probe.
+  void ProbeSent(int64_t now_ms, size_t probe_size);
 
  private:
   enum class ProbingState {
     // Probing will not be triggered in this state at all times.
     kDisabled,
     // Probing is enabled and ready to trigger on the first packet arrival.
     kInactive,
     // Probe cluster is filled with the set of data rates to be probed and
     // probes are being sent.
     kActive,
     // Probing is enabled, but currently suspended until an explicit trigger
     // to start probing again.
     kSuspended,
   };
 
+  // A probe cluster consists of a set of probes. Each probe in turn can be
+  // divided into a number of packets to accomodate the MTU on the network.
   struct ProbeCluster {
-    int max_probe_packets = 0;
-    int sent_probe_packets = 0;
+    int max_probes = 0;
+    int sent_probes = 0;
     int probe_bitrate_bps = 0;
     int id = -1;
   };
 
   // Resets the state of the prober and clears any cluster/timing data tracked.
   void ResetState();
 
   ProbingState probing_state_;
   // Probe bitrate per packet. These are used to compute the delta relative to
   // the previous probe packet based on the size and time when that packet was
   // sent.
   std::queue<ProbeCluster> clusters_;
-  size_t packet_size_last_sent_;
+  // A probe can include one or more packets.
+  size_t probe_size_last_sent_;
   // The last time a probe was sent.
   int64_t time_last_probe_sent_ms_;
   int next_cluster_id_;
 };
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_PACING_BITRATE_PROBER_H_