packet_router.h - mozsearch

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/*

 *  Copyright (c) 2015 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.

*/

#ifndef MODULES_PACING_PACKET_ROUTER_H_

#define MODULES_PACING_PACKET_ROUTER_H_

#include <stddef.h>

#include <stdint.h>

#include <cstdint>

#include <list>

#include <memory>

#include <optional>

#include <set>

#include <unordered_map>

#include <vector>

#include "absl/functional/any_invocable.h"

#include "api/array_view.h"

#include "api/sequence_checker.h"

#include "api/transport/network_types.h"

#include "api/units/data_size.h"

#include "modules/pacing/pacing_controller.h"

#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"

#include "modules/rtp_rtcp/source/rtcp_packet.h"

#include "modules/rtp_rtcp/source/rtp_packet_to_send.h"

#include "rtc_base/thread_annotations.h"

namespace webrtc {

class RtpRtcpInterface;

// PacketRouter keeps track of rtp send modules to support the pacer.

// In addition, it handles feedback messages, which are sent on a send

// module if possible (sender report), otherwise on receive module

// (receiver report). For the latter case, we also keep track of the

// receive modules.

class PacketRouter : public PacingController::PacketSender {

 public:

  PacketRouter();

  ~PacketRouter() override;

  PacketRouter(const PacketRouter&) = delete;

  PacketRouter& operator=(const PacketRouter&) = delete;

  // Callback is invoked after pacing, before a packet is forwarded to the

  // sending rtp module.

  void RegisterNotifyBweCallback(

      absl::AnyInvocable<void(const RtpPacketToSend& packet,

                              const PacedPacketInfo& pacing_info)> callback);

  void AddSendRtpModule(RtpRtcpInterface* rtp_module, bool remb_candidate);

  void RemoveSendRtpModule(RtpRtcpInterface* rtp_module);

  bool SupportsRtxPayloadPadding() const;

  void AddReceiveRtpModule(RtcpFeedbackSenderInterface* rtcp_sender,

                           bool remb_candidate);

  void RemoveReceiveRtpModule(RtcpFeedbackSenderInterface* rtcp_sender);

  void SendPacket(std::unique_ptr<RtpPacketToSend> packet,

                  const PacedPacketInfo& cluster_info) override;

  std::vector<std::unique_ptr<RtpPacketToSend>> FetchFec() override;

  std::vector<std::unique_ptr<RtpPacketToSend>> GeneratePadding(

      DataSize size) override;

  void OnAbortedRetransmissions(

      uint32_t ssrc,

      rtc::ArrayView<const uint16_t> sequence_numbers) override;

  std::optional<uint32_t> GetRtxSsrcForMedia(uint32_t ssrc) const override;

  void OnBatchComplete() override;

  // Send REMB feedback.

  void SendRemb(int64_t bitrate_bps, std::vector<uint32_t> ssrcs);

  // Sends `packets` in one or more IP packets.

  void SendCombinedRtcpPacket(

      std::vector<std::unique_ptr<rtcp::RtcpPacket>> packets);

 private:

  void AddRembModuleCandidate(RtcpFeedbackSenderInterface* candidate_module,

                              bool media_sender);

  void MaybeRemoveRembModuleCandidate(

      RtcpFeedbackSenderInterface* candidate_module,

      bool media_sender);

  void UnsetActiveRembModule();

  void DetermineActiveRembModule();

  void AddSendRtpModuleToMap(RtpRtcpInterface* rtp_module, uint32_t ssrc);

  void RemoveSendRtpModuleFromMap(uint32_t ssrc);

  SequenceChecker thread_checker_;

  // Ssrc to RtpRtcpInterface module;

  std::unordered_map<uint32_t, RtpRtcpInterface*> send_modules_map_

      RTC_GUARDED_BY(thread_checker_);

  std::list<RtpRtcpInterface*> send_modules_list_

      RTC_GUARDED_BY(thread_checker_);

  // The last module used to send media.

  RtpRtcpInterface* last_send_module_ RTC_GUARDED_BY(thread_checker_);

  // Rtcp modules of the rtp receivers.

  std::vector<RtcpFeedbackSenderInterface*> rtcp_feedback_senders_

      RTC_GUARDED_BY(thread_checker_);

  // Candidates for the REMB module can be RTP sender/receiver modules, with

  // the sender modules taking precedence.

  std::vector<RtcpFeedbackSenderInterface*> sender_remb_candidates_

      RTC_GUARDED_BY(thread_checker_);

  std::vector<RtcpFeedbackSenderInterface*> receiver_remb_candidates_

      RTC_GUARDED_BY(thread_checker_);

  RtcpFeedbackSenderInterface* active_remb_module_

      RTC_GUARDED_BY(thread_checker_);

  uint64_t transport_seq_ RTC_GUARDED_BY(thread_checker_);

  absl::AnyInvocable<void(RtpPacketToSend& packet,

                          const PacedPacketInfo& pacing_info)>

      notify_bwe_callback_ RTC_GUARDED_BY(thread_checker_) = nullptr;

  std::vector<std::unique_ptr<RtpPacketToSend>> pending_fec_packets_

      RTC_GUARDED_BY(thread_checker_);

  std::set<RtpRtcpInterface*> modules_used_in_current_batch_

      RTC_GUARDED_BY(thread_checker_);

};

}  // namespace webrtc

#endif  // MODULES_PACING_PACKET_ROUTER_H_