1 files changed, 41 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/congestion_controller/pcc/rtt_tracker.cc b/third_party/libwebrtc/modules/congestion_controller/pcc/rtt_tracker.cc
new file mode 100644
index 0000000000..af9dc8f11b
--- /dev/null
+++ b/third_party/libwebrtc/modules/congestion_controller/pcc/rtt_tracker.cc
@@ -0,0 +1,41 @@
+/*
+ *  Copyright (c) 2018 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.
+ */
+
+#include "modules/congestion_controller/pcc/rtt_tracker.h"
+
+#include <algorithm>
+
+namespace webrtc {
+namespace pcc {
+
+RttTracker::RttTracker(TimeDelta initial_rtt, double alpha)
+    : rtt_estimate_(initial_rtt), alpha_(alpha) {}
+
+void RttTracker::OnPacketsFeedback(
+    const std::vector<PacketResult>& packet_feedbacks,
+    Timestamp feedback_received_time) {
+  TimeDelta packet_rtt = TimeDelta::MinusInfinity();
+  for (const PacketResult& packet_result : packet_feedbacks) {
+    if (!packet_result.IsReceived())
+      continue;
+    packet_rtt = std::max<TimeDelta>(
+        packet_rtt,
+        feedback_received_time - packet_result.sent_packet.send_time);
+  }
+  if (packet_rtt.IsFinite())
+    rtt_estimate_ = (1 - alpha_) * rtt_estimate_ + alpha_ * packet_rtt;
+}
+
+TimeDelta RttTracker::GetRtt() const {
+  return rtt_estimate_;
+}
+
+}  // namespace pcc
+}  // namespace webrtc