Add functionality which limits the number of bytes on the network.

webrtc/modules/congestion_controller/transport_feedback_adapter.cc

Index: webrtc/modules/congestion_controller/transport_feedback_adapter.cc
diff --git a/webrtc/modules/congestion_controller/transport_feedback_adapter.cc b/webrtc/modules/congestion_controller/transport_feedback_adapter.cc
index 7f3f744ecf70a811610fc7fd05a6d87811b07ffb..8f6776ab2aa608478371321c35df63528fe9fffd 100644
--- a/webrtc/modules/congestion_controller/transport_feedback_adapter.cc
+++ b/webrtc/modules/congestion_controller/transport_feedback_adapter.cc
@@ -10,6 +10,8 @@
 
 #include "webrtc/modules/congestion_controller/transport_feedback_adapter.h"
 
+#include <algorithm>
+
 #include "webrtc/modules/congestion_controller/delay_based_bwe.h"
 #include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
 #include "webrtc/rtc_base/checks.h"
@@ -34,7 +36,8 @@ TransportFeedbackAdapter::TransportFeedbackAdapter(const Clock* clock)
       current_offset_ms_(kNoTimestamp),
       last_timestamp_us_(kNoTimestamp),
       local_net_id_(0),
-      remote_net_id_(0) {}
+      remote_net_id_(0),
+      min_feedback_rtt_(-1) {}

[philipel, 2017/08/02 15:35:15]

Maybe use optional instead of magic -1?

[stefan-webrtc, 2017/08/04 09:50:00]

Done.

 
 TransportFeedbackAdapter::~TransportFeedbackAdapter() {
   RTC_DCHECK(observers_.empty());
@@ -128,7 +131,7 @@ std::vector<PacketFeedback> TransportFeedbackAdapter::GetPacketFeedbackVector(
     return packet_feedback_vector;
   }
   packet_feedback_vector.reserve(feedback.GetPacketStatusCount());
-
+  int64_t feedback_rtt = -1;
   {
     rtc::CritScope cs(&lock_);
     size_t failed_lookups = 0;
@@ -158,6 +161,10 @@ std::vector<PacketFeedback> TransportFeedbackAdapter::GetPacketFeedbackVector(
         ++failed_lookups;
       if (packet_feedback.local_net_id == local_net_id_ &&
           packet_feedback.remote_net_id == remote_net_id_) {
+        if (feedback_rtt == -1 && packet_feedback.send_time_ms >= 0) {
+          feedback_rtt =
+              clock_->TimeInMilliseconds() - packet_feedback.send_time_ms;
+        }
         packet_feedback_vector.push_back(packet_feedback);
       }
 
@@ -169,6 +176,14 @@ std::vector<PacketFeedback> TransportFeedbackAdapter::GetPacketFeedbackVector(
                       << " packet" << (failed_lookups > 1 ? "s" : "")
                       << ". Send time history too small?";
     }
+    if (feedback_rtt > -1) {
+      feedback_rtts_.push_back(feedback_rtt);
+      const size_t kFeedbackRttWindow = 32;
+      if (feedback_rtts_.size() > kFeedbackRttWindow)
+        feedback_rtts_.pop_front();
+      min_feedback_rtt_ =
+          *std::min_element(feedback_rtts_.begin(), feedback_rtts_.end());
+    }
   }
   return packet_feedback_vector;
 }
@@ -188,4 +203,14 @@ std::vector<PacketFeedback>
 TransportFeedbackAdapter::GetTransportFeedbackVector() const {
   return last_packet_feedback_vector_;
 }
+
+int64_t TransportFeedbackAdapter::GetMinFeedbackLoopRtt() const {
+  rtc::CritScope cs(&lock_);
+  return min_feedback_rtt_;
+}
+
+size_t TransportFeedbackAdapter::GetOutstandingBytes() const {
+  rtc::CritScope cs(&lock_);
+  return send_time_history_.GetOutstandingBytes(local_net_id_, remote_net_id_);
+}
 }  // namespace webrtc