Move congestion controller to a separate module.

webrtc/call/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/call/congestion_controller.h"
-
-#include <algorithm>
-#include <vector>
-
-#include "webrtc/base/checks.h"
-#include "webrtc/base/logging.h"
-#include "webrtc/base/socket.h"
-#include "webrtc/base/thread_annotations.h"
-#include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"
-#include "webrtc/modules/pacing/paced_sender.h"
-#include "webrtc/modules/remote_bitrate_estimator/include/send_time_history.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"
-#include "webrtc/modules/utility/include/process_thread.h"
-#include "webrtc/system_wrappers/include/critical_section_wrapper.h"
-#include "webrtc/video/payload_router.h"
-
-namespace webrtc {
-namespace {
-
-static const uint32_t kTimeOffsetSwitchThreshold = 30;
-
-class WrappingBitrateEstimator : public RemoteBitrateEstimator {
- public:
-  WrappingBitrateEstimator(RemoteBitrateObserver* observer, Clock* clock)
-      : observer_(observer),
-        clock_(clock),
-        crit_sect_(CriticalSectionWrapper::CreateCriticalSection()),
-        rbe_(new RemoteBitrateEstimatorSingleStream(observer_, clock_)),
-        using_absolute_send_time_(false),
-        packets_since_absolute_send_time_(0),
-        min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps) {}
-
-  virtual ~WrappingBitrateEstimator() {}
-
-  void IncomingPacket(int64_t arrival_time_ms,
-                      size_t payload_size,
-                      const RTPHeader& header,
-                      bool was_paced) override {
-    CriticalSectionScoped cs(crit_sect_.get());
-    PickEstimatorFromHeader(header);
-    rbe_->IncomingPacket(arrival_time_ms, payload_size, header, was_paced);
-  }
-
-  int32_t Process() override {
-    CriticalSectionScoped cs(crit_sect_.get());
-    return rbe_->Process();
-  }
-
-  int64_t TimeUntilNextProcess() override {
-    CriticalSectionScoped cs(crit_sect_.get());
-    return rbe_->TimeUntilNextProcess();
-  }
-
-  void OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) override {
-    CriticalSectionScoped cs(crit_sect_.get());
-    rbe_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
-  }
-
-  void RemoveStream(unsigned int ssrc) override {
-    CriticalSectionScoped cs(crit_sect_.get());
-    rbe_->RemoveStream(ssrc);
-  }
-
-  bool LatestEstimate(std::vector<unsigned int>* ssrcs,
-                      unsigned int* bitrate_bps) const override {
-    CriticalSectionScoped cs(crit_sect_.get());
-    return rbe_->LatestEstimate(ssrcs, bitrate_bps);
-  }
-
-  void SetMinBitrate(int min_bitrate_bps) {
-    CriticalSectionScoped cs(crit_sect_.get());
-    rbe_->SetMinBitrate(min_bitrate_bps);
-    min_bitrate_bps_ = min_bitrate_bps;
-  }
-
- private:
-  void PickEstimatorFromHeader(const RTPHeader& header)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_sect_.get()) {
-    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 PickEstimator() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_.get()) {
-    if (using_absolute_send_time_) {
-      rbe_.reset(new RemoteBitrateEstimatorAbsSendTime(observer_, clock_));
-    } else {
-      rbe_.reset(new RemoteBitrateEstimatorSingleStream(observer_, clock_));
-    }
-    rbe_->SetMinBitrate(min_bitrate_bps_);
-  }
-
-  RemoteBitrateObserver* observer_;
-  Clock* const clock_;
-  rtc::scoped_ptr<CriticalSectionWrapper> crit_sect_;
-  rtc::scoped_ptr<RemoteBitrateEstimator> rbe_;
-  bool using_absolute_send_time_;
-  uint32_t packets_since_absolute_send_time_;
-  int min_bitrate_bps_;
-
-  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(WrappingBitrateEstimator);
-};
-
-}  // namespace
-
-CongestionController::CongestionController(
-    Clock* clock,
-    BitrateObserver* bitrate_observer,
-    RemoteBitrateObserver* remote_bitrate_observer)
-    : clock_(clock),
-      pacer_(new PacedSender(clock_,
-             &packet_router_,
-             BitrateController::kDefaultStartBitrateKbps,
-             PacedSender::kDefaultPaceMultiplier *
-                 BitrateController::kDefaultStartBitrateKbps,
-             0)),
-      remote_bitrate_estimator_(
-          new WrappingBitrateEstimator(remote_bitrate_observer, clock_)),
-      pacer_thread_(ProcessThread::Create("PacerThread")),
-      // Constructed last as this object calls the provided callback on
-      // construction.
-      bitrate_controller_(
-          BitrateController::CreateBitrateController(clock_, bitrate_observer)),
-      remote_estimator_proxy_(clock_, &packet_router_),
-      transport_feedback_adapter_(bitrate_controller_.get(), clock_),
-      min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps) {
-  transport_feedback_adapter_.SetBitrateEstimator(
-      new RemoteBitrateEstimatorAbsSendTime(&transport_feedback_adapter_,
-                                            clock_));
-  transport_feedback_adapter_.GetBitrateEstimator()->SetMinBitrate(
-      min_bitrate_bps_);
-  pacer_thread_->RegisterModule(pacer_.get());
-  pacer_thread_->RegisterModule(&remote_estimator_proxy_);
-  pacer_thread_->Start();
-}
-
-CongestionController::~CongestionController() {
-  pacer_thread_->Stop();
-  pacer_thread_->DeRegisterModule(pacer_.get());
-  pacer_thread_->DeRegisterModule(&remote_estimator_proxy_);
-}
-
-
-void CongestionController::SetBweBitrates(int min_bitrate_bps,
-                                          int start_bitrate_bps,
-                                          int max_bitrate_bps) {
-  RTC_DCHECK(config_thread_checker_.CalledOnValidThread());
-  // 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.
-  const int kMinBitrateBps = 10000;
-  if (min_bitrate_bps < kMinBitrateBps)
-    min_bitrate_bps = kMinBitrateBps;
-  if (max_bitrate_bps > 0)
-    max_bitrate_bps = std::max(min_bitrate_bps, max_bitrate_bps);
-  if (start_bitrate_bps > 0) {
-    start_bitrate_bps = std::max(min_bitrate_bps, start_bitrate_bps);
-    bitrate_controller_->SetStartBitrate(start_bitrate_bps);
-  }
-  bitrate_controller_->SetMinMaxBitrate(min_bitrate_bps, max_bitrate_bps);
-  if (remote_bitrate_estimator_)
-    remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);
-  min_bitrate_bps_ = min_bitrate_bps;
-  transport_feedback_adapter_.GetBitrateEstimator()->SetMinBitrate(
-      min_bitrate_bps_);
-}
-
-BitrateController* CongestionController::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_.get();
-  }
-}
-
-TransportFeedbackObserver*
-CongestionController::GetTransportFeedbackObserver() {
-  RTC_DCHECK(config_thread_checker_.CalledOnValidThread());
-  return &transport_feedback_adapter_;
-}
-
-void CongestionController::UpdatePacerBitrate(int bitrate_kbps,
-                                              int max_bitrate_kbps,
-                                              int min_bitrate_kbps) {
-  pacer_->UpdateBitrate(bitrate_kbps, max_bitrate_kbps, min_bitrate_kbps);
-}
-
-int64_t CongestionController::GetPacerQueuingDelayMs() const {
-  return pacer_->QueueInMs();
-}
-
-void CongestionController::SignalNetworkState(NetworkState state) {
-  if (state == kNetworkUp) {
-    pacer_->Resume();
-  } else {
-    pacer_->Pause();
-  }
-}
-
-void CongestionController::OnSentPacket(const rtc::SentPacket& sent_packet) {
-  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);
-  transport_feedback_adapter_.OnRttUpdate(avg_rtt_ms, max_rtt_ms);
-}
-
-int64_t CongestionController::TimeUntilNextProcess() {
-  return std::min(bitrate_controller_->TimeUntilNextProcess(),
-                  remote_bitrate_estimator_->TimeUntilNextProcess());
-}
-
-int32_t CongestionController::Process() {
-  bitrate_controller_->Process();
-  remote_bitrate_estimator_->Process();
-  return 0;
-}
-
-}  // namespace webrtc