Split CongestionController into send- and receive-side classes.

webrtc/modules/congestion_controller/send_side_congestion_controller.cc

 /*
  *  Copyright (c) 2012 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 "webrtc/modules/congestion_controller/include/congestion_controller.h"
+#include "webrtc/modules/congestion_controller/include/send_side_congestion_controller.h"
 
 #include <algorithm>
 #include <memory>
 #include <vector>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/rate_limiter.h"
 #include "webrtc/base/socket.h"
 #include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"
 #include "webrtc/modules/congestion_controller/probe_controller.h"
 #include "webrtc/modules/remote_bitrate_estimator/include/bwe_defines.h"
-#include "webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_abs_send_time.h"
-#include "webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h"
 
 namespace webrtc {
 namespace {
 
-static const uint32_t kTimeOffsetSwitchThreshold = 30;
 static const int64_t kRetransmitWindowSizeMs = 500;
 
 // Makes sure that the bitrate and the min, max values are in valid range.
 static void ClampBitrates(int* bitrate_bps,
                           int* min_bitrate_bps,
                           int* max_bitrate_bps) {
   // TODO(holmer): We should make sure the default bitrates are set to 10 kbps,
   // and that we don't try to set the min bitrate to 0 from any applications.
   // The congestion controller should allow a min bitrate of 0.
   if (*min_bitrate_bps < congestion_controller::GetMinBitrateBps())
     *min_bitrate_bps = congestion_controller::GetMinBitrateBps();
   if (*max_bitrate_bps > 0)
     *max_bitrate_bps = std::max(*min_bitrate_bps, *max_bitrate_bps);
   if (*bitrate_bps > 0)
     *bitrate_bps = std::max(*min_bitrate_bps, *bitrate_bps);
 }
 
 }  // namespace
 
-CongestionController::WrappingBitrateEstimator::WrappingBitrateEstimator(
-    RemoteBitrateObserver* observer, const Clock* clock)
-    : observer_(observer),
-      clock_(clock),
-      rbe_(new RemoteBitrateEstimatorSingleStream(observer_, clock_)),
-      using_absolute_send_time_(false),
-      packets_since_absolute_send_time_(0),
-      min_bitrate_bps_(congestion_controller::GetMinBitrateBps()) {}
-
-void CongestionController::WrappingBitrateEstimator::IncomingPacket(
-    int64_t arrival_time_ms,
-    size_t payload_size,
-    const RTPHeader& header) {
-  rtc::CritScope cs(&crit_sect_);
-  PickEstimatorFromHeader(header);
-  rbe_->IncomingPacket(arrival_time_ms, payload_size, header);
-}
-
-void CongestionController::WrappingBitrateEstimator::Process() {
-  rtc::CritScope cs(&crit_sect_);
-  rbe_->Process();
-}
-
-int64_t CongestionController::WrappingBitrateEstimator::TimeUntilNextProcess() {
-  rtc::CritScope cs(&crit_sect_);
-  return rbe_->TimeUntilNextProcess();
-}
-
-void CongestionController::WrappingBitrateEstimator::OnRttUpdate(
-    int64_t avg_rtt_ms, int64_t max_rtt_ms) {
-  rtc::CritScope cs(&crit_sect_);
-  rbe_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
-}
-
-void CongestionController::WrappingBitrateEstimator::RemoveStream(
-    unsigned int ssrc) {
-  rtc::CritScope cs(&crit_sect_);
-  rbe_->RemoveStream(ssrc);
-}
-
-bool CongestionController::WrappingBitrateEstimator::LatestEstimate(
-    std::vector<unsigned int>* ssrcs,
-    unsigned int* bitrate_bps) const {
-  rtc::CritScope cs(&crit_sect_);
-  return rbe_->LatestEstimate(ssrcs, bitrate_bps);
-}
-
-void CongestionController::WrappingBitrateEstimator::SetMinBitrate(
-    int min_bitrate_bps) {
-  rtc::CritScope cs(&crit_sect_);
-  rbe_->SetMinBitrate(min_bitrate_bps);
-  min_bitrate_bps_ = min_bitrate_bps;
-}
-
-void CongestionController::WrappingBitrateEstimator::PickEstimatorFromHeader(
-    const RTPHeader& header) {
-  if (header.extension.hasAbsoluteSendTime) {
-    // If we see AST in header, switch RBE strategy immediately.
-    if (!using_absolute_send_time_) {
-      LOG(LS_INFO) <<
-          "WrappingBitrateEstimator: Switching to absolute send time RBE.";
-      using_absolute_send_time_ = true;
-      PickEstimator();
-    }
-    packets_since_absolute_send_time_ = 0;
-  } else {
-    // When we don't see AST, wait for a few packets before going back to TOF.
-    if (using_absolute_send_time_) {
-      ++packets_since_absolute_send_time_;
-      if (packets_since_absolute_send_time_ >= kTimeOffsetSwitchThreshold) {
-        LOG(LS_INFO) << "WrappingBitrateEstimator: Switching to transmission "
-                     << "time offset RBE.";
-        using_absolute_send_time_ = false;
-        PickEstimator();
-      }
-    }
-  }
-}
-
-// Instantiate RBE for Time Offset or Absolute Send Time extensions.
-void CongestionController::WrappingBitrateEstimator::PickEstimator() {
-  if (using_absolute_send_time_) {
-    rbe_.reset(new RemoteBitrateEstimatorAbsSendTime(observer_, clock_));
-  } else {
-    rbe_.reset(new RemoteBitrateEstimatorSingleStream(observer_, clock_));
-  }
-  rbe_->SetMinBitrate(min_bitrate_bps_);
-}
-
-CongestionController::CongestionController(
+SendSideCongestionController::SendSideCongestionController(
     const Clock* clock,
     Observer* observer,
-    RemoteBitrateObserver* remote_bitrate_observer,
     RtcEventLog* event_log,
     PacketRouter* packet_router)
-    : CongestionController(
+    : SendSideCongestionController(
           clock,
           observer,
-          remote_bitrate_observer,
           event_log,
-          packet_router,
           std::unique_ptr<PacedSender>(new PacedSender(clock, packet_router))) {
 }
 
-CongestionController::CongestionController(
+SendSideCongestionController::SendSideCongestionController(
     const Clock* clock,
     Observer* observer,
-    RemoteBitrateObserver* remote_bitrate_observer,
     RtcEventLog* event_log,
-    PacketRouter* packet_router,
     std::unique_ptr<PacedSender> pacer)
     : clock_(clock),
       observer_(observer),
       event_log_(event_log),
-      packet_router_(packet_router),
       pacer_(std::move(pacer)),
       bitrate_controller_(
           BitrateController::CreateBitrateController(clock_, event_log)),
       probe_controller_(new ProbeController(pacer_.get(), clock_)),
       retransmission_rate_limiter_(
           new RateLimiter(clock, kRetransmitWindowSizeMs)),
-      remote_bitrate_estimator_(remote_bitrate_observer, clock_),
-      remote_estimator_proxy_(clock_, packet_router_),
       transport_feedback_adapter_(clock_),
       last_reported_bitrate_bps_(0),
       last_reported_fraction_loss_(0),
       last_reported_rtt_(0),
       network_state_(kNetworkUp),
       min_bitrate_bps_(congestion_controller::GetMinBitrateBps()),
       delay_based_bwe_(new DelayBasedBwe(event_log_, clock_)) {
   delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
   worker_thread_checker_.DetachFromThread();
 }
 
-CongestionController::~CongestionController() {}
+SendSideCongestionController::~SendSideCongestionController() {}
 
-void CongestionController::OnReceivedPacket(int64_t arrival_time_ms,
-                                            size_t payload_size,
-                                            const RTPHeader& header) {
-  // Send-side BWE.
-  if (header.extension.hasTransportSequenceNumber) {
-    remote_estimator_proxy_.IncomingPacket(arrival_time_ms, payload_size,
-                                           header);
-  } else {
-    // Receive-side BWE.
-    remote_bitrate_estimator_.IncomingPacket(arrival_time_ms, payload_size,
-                                              header);
-  }
-}
-
-void CongestionController::SetBweBitrates(int min_bitrate_bps,
-                                          int start_bitrate_bps,
-                                          int max_bitrate_bps) {
+void SendSideCongestionController::SetBweBitrates(int min_bitrate_bps,
+                                                  int start_bitrate_bps,
+                                                  int max_bitrate_bps) {
   ClampBitrates(&start_bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
-  bitrate_controller_->SetBitrates(start_bitrate_bps,
-                                   min_bitrate_bps,
+  bitrate_controller_->SetBitrates(start_bitrate_bps, min_bitrate_bps,
                                    max_bitrate_bps);
 
   probe_controller_->SetBitrates(min_bitrate_bps, start_bitrate_bps,
                                  max_bitrate_bps);
 
-  remote_bitrate_estimator_.SetMinBitrate(min_bitrate_bps);
   {
     rtc::CritScope cs(&bwe_lock_);
     if (start_bitrate_bps > 0)
       delay_based_bwe_->SetStartBitrate(start_bitrate_bps);
     min_bitrate_bps_ = min_bitrate_bps;
     delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
   }
   MaybeTriggerOnNetworkChanged();
 }
 
 // TODO(holmer): Split this up and use SetBweBitrates in combination with
 // OnNetworkRouteChanged.
-void CongestionController::OnNetworkRouteChanged(
+void SendSideCongestionController::OnNetworkRouteChanged(
     const rtc::NetworkRoute& network_route,
     int bitrate_bps,
     int min_bitrate_bps,
     int max_bitrate_bps) {
   ClampBitrates(&bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
   // TODO(honghaiz): Recreate this object once the bitrate controller is
-  // no longer exposed outside CongestionController.
+  // no longer exposed outside SendSideCongestionController.
   bitrate_controller_->ResetBitrates(bitrate_bps, min_bitrate_bps,
                                      max_bitrate_bps);
-  // TODO(honghaiz): Recreate this object once the remote bitrate estimator is
-  // no longer exposed outside CongestionController.
-  remote_bitrate_estimator_.SetMinBitrate(min_bitrate_bps);
 
   transport_feedback_adapter_.SetNetworkIds(network_route.local_network_id,
                                             network_route.remote_network_id);
   {
     rtc::CritScope cs(&bwe_lock_);
     min_bitrate_bps_ = min_bitrate_bps;
     delay_based_bwe_.reset(new DelayBasedBwe(event_log_, clock_));
     delay_based_bwe_->SetStartBitrate(bitrate_bps);
-    delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
+    delay_based_bwe_->SetMinBitrate(min_bitrate_bps);
   }
 
   probe_controller_->Reset();
   probe_controller_->SetBitrates(min_bitrate_bps, bitrate_bps, max_bitrate_bps);
 
   MaybeTriggerOnNetworkChanged();
 }
 
-BitrateController* CongestionController::GetBitrateController() const {
+BitrateController* SendSideCongestionController::GetBitrateController() const {
   return bitrate_controller_.get();
 }
 
-RemoteBitrateEstimator* CongestionController::GetRemoteBitrateEstimator(
-    bool send_side_bwe) {
-  if (send_side_bwe) {
-    return &remote_estimator_proxy_;
-  } else {
-    return &remote_bitrate_estimator_;
-  }
-}
-
-RateLimiter* CongestionController::GetRetransmissionRateLimiter() {
+RateLimiter* SendSideCongestionController::GetRetransmissionRateLimiter() {
   return retransmission_rate_limiter_.get();
 }
 
-void CongestionController::EnablePeriodicAlrProbing(bool enable) {
+void SendSideCongestionController::EnablePeriodicAlrProbing(bool enable) {
   probe_controller_->EnablePeriodicAlrProbing(enable);
 }
 
-void CongestionController::SetAllocatedSendBitrateLimits(
+void SendSideCongestionController::SetAllocatedSendBitrateLimits(
     int min_send_bitrate_bps,
     int max_padding_bitrate_bps) {
   pacer_->SetSendBitrateLimits(min_send_bitrate_bps, max_padding_bitrate_bps);
 }
 
-int64_t CongestionController::GetPacerQueuingDelayMs() const {
+int64_t SendSideCongestionController::GetPacerQueuingDelayMs() const {
   return IsNetworkDown() ? 0 : pacer_->QueueInMs();
 }
 
-void CongestionController::SignalNetworkState(NetworkState state) {
+void SendSideCongestionController::SignalNetworkState(NetworkState state) {
   LOG(LS_INFO) << "SignalNetworkState "
                << (state == kNetworkUp ? "Up" : "Down");
   if (state == kNetworkUp) {
     pacer_->Resume();
   } else {
     pacer_->Pause();
   }
   {
     rtc::CritScope cs(&network_state_lock_);
     network_state_ = state;
   }
   probe_controller_->OnNetworkStateChanged(state);
   MaybeTriggerOnNetworkChanged();
 }
 
-void CongestionController::SetTransportOverhead(
+void SendSideCongestionController::SetTransportOverhead(
     size_t transport_overhead_bytes_per_packet) {
   transport_feedback_adapter_.SetTransportOverhead(
       transport_overhead_bytes_per_packet);
 }
 
-void CongestionController::OnSentPacket(const rtc::SentPacket& sent_packet) {
+void SendSideCongestionController::OnSentPacket(
+    const rtc::SentPacket& sent_packet) {
   // We're not interested in packets without an id, which may be stun packets,
   // etc, sent on the same transport.
   if (sent_packet.packet_id == -1)
     return;
   transport_feedback_adapter_.OnSentPacket(sent_packet.packet_id,
                                            sent_packet.send_time_ms);
 }
 
-void CongestionController::OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) {
-  remote_bitrate_estimator_.OnRttUpdate(avg_rtt_ms, max_rtt_ms);
-  {
-    rtc::CritScope cs(&bwe_lock_);
-    delay_based_bwe_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
-  }
+void SendSideCongestionController::OnRttUpdate(int64_t avg_rtt_ms,
+                                               int64_t max_rtt_ms) {
+  rtc::CritScope cs(&bwe_lock_);
+  delay_based_bwe_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
 }
 
-int64_t CongestionController::TimeUntilNextProcess() {
-  return std::min(bitrate_controller_->TimeUntilNextProcess(),
-                  remote_bitrate_estimator_.TimeUntilNextProcess());
+int64_t SendSideCongestionController::TimeUntilNextProcess() {
+  return bitrate_controller_->TimeUntilNextProcess();
 }
 
-void CongestionController::Process() {
+void SendSideCongestionController::Process() {
   bitrate_controller_->Process();
-  remote_bitrate_estimator_.Process();
   probe_controller_->Process();
   MaybeTriggerOnNetworkChanged();
 }
 
-void CongestionController::AddPacket(uint16_t sequence_number,
-                                     size_t length,
-                                     const PacedPacketInfo& pacing_info) {
+void SendSideCongestionController::AddPacket(
+    uint16_t sequence_number,
+    size_t length,
+    const PacedPacketInfo& pacing_info) {
   transport_feedback_adapter_.AddPacket(sequence_number, length, pacing_info);
 }
 
-void CongestionController::OnTransportFeedback(
+void SendSideCongestionController::OnTransportFeedback(
     const rtcp::TransportFeedback& feedback) {
   RTC_DCHECK(worker_thread_checker_.CalledOnValidThread());
   transport_feedback_adapter_.OnTransportFeedback(feedback);
   std::vector<PacketFeedback> feedback_vector =
       transport_feedback_adapter_.GetTransportFeedbackVector();
   if (feedback_vector.empty())
     return;
   DelayBasedBwe::Result result;
   {
     rtc::CritScope cs(&bwe_lock_);
     result = delay_based_bwe_->IncomingPacketFeedbackVector(feedback_vector);
   }
   if (result.updated)
     bitrate_controller_->OnDelayBasedBweResult(result);
 }
 
-std::vector<PacketFeedback> CongestionController::GetTransportFeedbackVector()
-    const {
+std::vector<PacketFeedback>
+SendSideCongestionController::GetTransportFeedbackVector() const {
   RTC_DCHECK(worker_thread_checker_.CalledOnValidThread());
   return transport_feedback_adapter_.GetTransportFeedbackVector();
 }
 
-void CongestionController::MaybeTriggerOnNetworkChanged() {
+void SendSideCongestionController::MaybeTriggerOnNetworkChanged() {
   // TODO(perkj): |observer_| can be nullptr if the ctor that accepts a
   // BitrateObserver is used. Remove this check once the ctor is removed.
   if (!observer_)
     return;
 
   uint32_t bitrate_bps;
   uint8_t fraction_loss;
   int64_t rtt;
   bool estimate_changed = bitrate_controller_->GetNetworkParameters(
       &bitrate_bps, &fraction_loss, &rtt);
   if (estimate_changed) {
     pacer_->SetEstimatedBitrate(bitrate_bps);
     probe_controller_->SetEstimatedBitrate(bitrate_bps);
     retransmission_rate_limiter_->SetMaxRate(bitrate_bps);
   }
 
   bitrate_bps = IsNetworkDown() || IsSendQueueFull() ? 0 : bitrate_bps;
 
   if (HasNetworkParametersToReportChanged(bitrate_bps, fraction_loss, rtt)) {
     int64_t probing_interval_ms;
     {
       rtc::CritScope cs(&bwe_lock_);
       probing_interval_ms = delay_based_bwe_->GetProbingIntervalMs();
     }
     observer_->OnNetworkChanged(bitrate_bps, fraction_loss, rtt,
                                 probing_interval_ms);
-    remote_estimator_proxy_.OnBitrateChanged(bitrate_bps);
   }
 }
 
-bool CongestionController::HasNetworkParametersToReportChanged(
+bool SendSideCongestionController::HasNetworkParametersToReportChanged(
     uint32_t bitrate_bps,
     uint8_t fraction_loss,
     int64_t rtt) {
   rtc::CritScope cs(&network_state_lock_);
   bool changed =
       last_reported_bitrate_bps_ != bitrate_bps ||
       (bitrate_bps > 0 && (last_reported_fraction_loss_ != fraction_loss ||
                            last_reported_rtt_ != rtt));
   if (changed && (last_reported_bitrate_bps_ == 0 || bitrate_bps == 0)) {
     LOG(LS_INFO) << "Bitrate estimate state changed, BWE: " << bitrate_bps
                  << " bps.";
   }
   last_reported_bitrate_bps_ = bitrate_bps;
   last_reported_fraction_loss_ = fraction_loss;
   last_reported_rtt_ = rtt;
   return changed;
 }
 
-bool CongestionController::IsSendQueueFull() const {
+bool SendSideCongestionController::IsSendQueueFull() const {
   return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
 }
 
-bool CongestionController::IsNetworkDown() const {
+bool SendSideCongestionController::IsNetworkDown() const {
   rtc::CritScope cs(&network_state_lock_);
   return network_state_ == kNetworkDown;
 }
 
 }  // namespace webrtc