modules/congestion_controller/rtp/transport_feedback_adapter.cc - src - Git at Google

 /*
  *  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.
  */

 #include "modules/congestion_controller/rtp/transport_feedback_adapter.h"

 #include <stdlib.h>

 #include <algorithm>
 #include <cmath>
 #include <utility>

 #include "absl/algorithm/container.h"
 #include "api/units/timestamp.h"
 #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"

 namespace webrtc {

 constexpr TimeDelta kSendTimeHistoryWindow = TimeDelta::Seconds(60);

 void InFlightBytesTracker::AddInFlightPacketBytes(
     const PacketFeedback& packet) {
   RTC_DCHECK(packet.sent.send_time.IsFinite());
   auto it = in_flight_data_.find(packet.network_route);
   if (it != in_flight_data_.end()) {
     it->second += packet.sent.size;
   } else {
     in_flight_data_.insert({packet.network_route, packet.sent.size});
   }
 }

 void InFlightBytesTracker::RemoveInFlightPacketBytes(
     const PacketFeedback& packet) {
   if (packet.sent.send_time.IsInfinite())
     return;
   auto it = in_flight_data_.find(packet.network_route);
   if (it != in_flight_data_.end()) {
     RTC_DCHECK_GE(it->second, packet.sent.size);
     it->second -= packet.sent.size;
     if (it->second.IsZero())
       in_flight_data_.erase(it);
   }
 }

 DataSize InFlightBytesTracker::GetOutstandingData(
     const rtc::NetworkRoute& network_route) const {
   auto it = in_flight_data_.find(network_route);
   if (it != in_flight_data_.end()) {
     return it->second;
   } else {
     return DataSize::Zero();
   }
 }

 // Comparator for consistent map with NetworkRoute as key.
 bool InFlightBytesTracker::NetworkRouteComparator::operator()(
     const rtc::NetworkRoute& a,
     const rtc::NetworkRoute& b) const {
   if (a.local.network_id() != b.local.network_id())
     return a.local.network_id() < b.local.network_id();
   if (a.remote.network_id() != b.remote.network_id())
     return a.remote.network_id() < b.remote.network_id();

   if (a.local.adapter_id() != b.local.adapter_id())
     return a.local.adapter_id() < b.local.adapter_id();
   if (a.remote.adapter_id() != b.remote.adapter_id())
     return a.remote.adapter_id() < b.remote.adapter_id();

   if (a.local.uses_turn() != b.local.uses_turn())
     return a.local.uses_turn() < b.local.uses_turn();
   if (a.remote.uses_turn() != b.remote.uses_turn())
     return a.remote.uses_turn() < b.remote.uses_turn();

   return a.connected < b.connected;
 }

 TransportFeedbackAdapter::TransportFeedbackAdapter() = default;

 void TransportFeedbackAdapter::AddPacket(const RtpPacketSendInfo& packet_info,
                                          size_t overhead_bytes,
                                          Timestamp creation_time) {
   PacketFeedback packet;
   packet.creation_time = creation_time;
   packet.sent.sequence_number =
       seq_num_unwrapper_.Unwrap(packet_info.transport_sequence_number);
   packet.sent.size = DataSize::Bytes(packet_info.length + overhead_bytes);
   packet.sent.audio = packet_info.packet_type == RtpPacketMediaType::kAudio;
   packet.network_route = network_route_;
   packet.sent.pacing_info = packet_info.pacing_info;

   while (!history_.empty() &&
          creation_time - history_.begin()->second.creation_time >
              kSendTimeHistoryWindow) {
     // TODO(sprang): Warn if erasing (too many) old items?
     if (history_.begin()->second.sent.sequence_number > last_ack_seq_num_)
       in_flight_.RemoveInFlightPacketBytes(history_.begin()->second);
     history_.erase(history_.begin());
   }
   history_.insert(std::make_pair(packet.sent.sequence_number, packet));
 }

 absl::optional<SentPacket> TransportFeedbackAdapter::ProcessSentPacket(
     const rtc::SentPacket& sent_packet) {
   auto send_time = Timestamp::Millis(sent_packet.send_time_ms);
   // TODO(srte): Only use one way to indicate that packet feedback is used.
   if (sent_packet.info.included_in_feedback || sent_packet.packet_id != -1) {
     int64_t unwrapped_seq_num =
         seq_num_unwrapper_.Unwrap(sent_packet.packet_id);
     auto it = history_.find(unwrapped_seq_num);
     if (it != history_.end()) {
       bool packet_retransmit = it->second.sent.send_time.IsFinite();
       it->second.sent.send_time = send_time;
       last_send_time_ = std::max(last_send_time_, send_time);
       // TODO(srte): Don't do this on retransmit.
       if (!pending_untracked_size_.IsZero()) {
         if (send_time < last_untracked_send_time_)
           RTC_LOG(LS_WARNING)
               << "appending acknowledged data for out of order packet. (Diff: "
               << ToString(last_untracked_send_time_ - send_time) << " ms.)";
         it->second.sent.prior_unacked_data += pending_untracked_size_;
         pending_untracked_size_ = DataSize::Zero();
       }
       if (!packet_retransmit) {
         if (it->second.sent.sequence_number > last_ack_seq_num_)
           in_flight_.AddInFlightPacketBytes(it->second);
         it->second.sent.data_in_flight = GetOutstandingData();
         return it->second.sent;
       }
     }
   } else if (sent_packet.info.included_in_allocation) {
     if (send_time < last_send_time_) {
       RTC_LOG(LS_WARNING) << "ignoring untracked data for out of order packet.";
     }
     pending_untracked_size_ +=
         DataSize::Bytes(sent_packet.info.packet_size_bytes);
     last_untracked_send_time_ = std::max(last_untracked_send_time_, send_time);
   }
   return absl::nullopt;
 }

 absl::optional<TransportPacketsFeedback>
 TransportFeedbackAdapter::ProcessTransportFeedback(
     const rtcp::TransportFeedback& feedback,
     Timestamp feedback_receive_time) {
   if (feedback.GetPacketStatusCount() == 0) {
     RTC_LOG(LS_INFO) << "Empty transport feedback packet received.";
     return absl::nullopt;
   }

   TransportPacketsFeedback msg;
   msg.feedback_time = feedback_receive_time;
   msg.packet_feedbacks =
       ProcessTransportFeedbackInner(feedback, feedback_receive_time);
   if (msg.packet_feedbacks.empty())
     return absl::nullopt;
   msg.data_in_flight = in_flight_.GetOutstandingData(network_route_);

   return msg;
 }

 void TransportFeedbackAdapter::SetNetworkRoute(
     const rtc::NetworkRoute& network_route) {
   network_route_ = network_route;
 }

 DataSize TransportFeedbackAdapter::GetOutstandingData() const {
   return in_flight_.GetOutstandingData(network_route_);
 }

 std::vector<PacketResult>
 TransportFeedbackAdapter::ProcessTransportFeedbackInner(
     const rtcp::TransportFeedback& feedback,
     Timestamp feedback_receive_time) {
   // Add timestamp deltas to a local time base selected on first packet arrival.
   // This won't be the true time base, but makes it easier to manually inspect
   // time stamps.
   if (last_timestamp_.IsInfinite()) {
     current_offset_ = feedback_receive_time;
   } else {
     // TODO(srte): We shouldn't need to do rounding here.
     const TimeDelta delta = feedback.GetBaseDelta(last_timestamp_)
                                 .RoundDownTo(TimeDelta::Millis(1));
     // Protect against assigning current_offset_ negative value.
     if (delta < Timestamp::Zero() - current_offset_) {
       RTC_LOG(LS_WARNING) << "Unexpected feedback timestamp received.";
       current_offset_ = feedback_receive_time;
     } else {
       current_offset_ += delta;
     }
   }
   last_timestamp_ = feedback.BaseTime();

   std::vector<PacketResult> packet_result_vector;
   packet_result_vector.reserve(feedback.GetPacketStatusCount());

   size_t failed_lookups = 0;
   size_t ignored = 0;

   feedback.ForAllPackets(
       [&](uint16_t sequence_number, TimeDelta delta_since_base) {
         int64_t seq_num = seq_num_unwrapper_.Unwrap(sequence_number);

         if (seq_num > last_ack_seq_num_) {
           // Starts at history_.begin() if last_ack_seq_num_ < 0, since any
           // valid sequence number is >= 0.
           for (auto it = history_.upper_bound(last_ack_seq_num_);
                it != history_.upper_bound(seq_num); ++it) {
             in_flight_.RemoveInFlightPacketBytes(it->second);
           }
           last_ack_seq_num_ = seq_num;
         }

         auto it = history_.find(seq_num);
         if (it == history_.end()) {
           ++failed_lookups;
           return;
         }

         if (it->second.sent.send_time.IsInfinite()) {
           // TODO(srte): Fix the tests that makes this happen and make this a
           // DCHECK.
           RTC_DLOG(LS_ERROR)
               << "Received feedback before packet was indicated as sent";
           return;
         }

         PacketFeedback packet_feedback = it->second;
         if (delta_since_base.IsFinite()) {
           packet_feedback.receive_time =
               current_offset_ +
               delta_since_base.RoundDownTo(TimeDelta::Millis(1));
           // Note: Lost packets are not removed from history because they might
           // be reported as received by a later feedback.
           history_.erase(it);
         }
         if (packet_feedback.network_route == network_route_) {
           PacketResult result;
           result.sent_packet = packet_feedback.sent;
           result.receive_time = packet_feedback.receive_time;
           packet_result_vector.push_back(result);
         } else {
           ++ignored;
         }
       });

   if (failed_lookups > 0) {
     RTC_LOG(LS_WARNING)
         << "Failed to lookup send time for " << failed_lookups << " packet"
         << (failed_lookups > 1 ? "s" : "")
         << ". Packets reordered or send time history too small?";
   }
   if (ignored > 0) {
     RTC_LOG(LS_INFO) << "Ignoring " << ignored
                      << " packets because they were sent on a different route.";
   }

   return packet_result_vector;
 }

 }  // namespace webrtc
	/*
	* 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.
	*/

	#include "modules/congestion_controller/rtp/transport_feedback_adapter.h"

	#include <stdlib.h>

	#include <algorithm>
	#include <cmath>
	#include <utility>

	#include "absl/algorithm/container.h"
	#include "api/units/timestamp.h"
	#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
	#include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
	#include "rtc_base/checks.h"
	#include "rtc_base/logging.h"

	namespace webrtc {

	constexpr TimeDelta kSendTimeHistoryWindow = TimeDelta::Seconds(60);

	void InFlightBytesTracker::AddInFlightPacketBytes(
	const PacketFeedback& packet) {
	RTC_DCHECK(packet.sent.send_time.IsFinite());
	auto it = in_flight_data_.find(packet.network_route);
	if (it != in_flight_data_.end()) {
	it->second += packet.sent.size;
	} else {
	in_flight_data_.insert({packet.network_route, packet.sent.size});
	}
	}

	void InFlightBytesTracker::RemoveInFlightPacketBytes(
	const PacketFeedback& packet) {
	if (packet.sent.send_time.IsInfinite())
	return;
	auto it = in_flight_data_.find(packet.network_route);
	if (it != in_flight_data_.end()) {
	RTC_DCHECK_GE(it->second, packet.sent.size);
	it->second -= packet.sent.size;
	if (it->second.IsZero())
	in_flight_data_.erase(it);
	}
	}

	DataSize InFlightBytesTracker::GetOutstandingData(
	const rtc::NetworkRoute& network_route) const {
	auto it = in_flight_data_.find(network_route);
	if (it != in_flight_data_.end()) {
	return it->second;
	} else {
	return DataSize::Zero();
	}
	}

	// Comparator for consistent map with NetworkRoute as key.
	bool InFlightBytesTracker::NetworkRouteComparator::operator()(
	const rtc::NetworkRoute& a,
	const rtc::NetworkRoute& b) const {
	if (a.local.network_id() != b.local.network_id())
	return a.local.network_id() < b.local.network_id();
	if (a.remote.network_id() != b.remote.network_id())
	return a.remote.network_id() < b.remote.network_id();

	if (a.local.adapter_id() != b.local.adapter_id())
	return a.local.adapter_id() < b.local.adapter_id();
	if (a.remote.adapter_id() != b.remote.adapter_id())
	return a.remote.adapter_id() < b.remote.adapter_id();

	if (a.local.uses_turn() != b.local.uses_turn())
	return a.local.uses_turn() < b.local.uses_turn();
	if (a.remote.uses_turn() != b.remote.uses_turn())
	return a.remote.uses_turn() < b.remote.uses_turn();

	return a.connected < b.connected;
	}

	TransportFeedbackAdapter::TransportFeedbackAdapter() = default;

	void TransportFeedbackAdapter::AddPacket(const RtpPacketSendInfo& packet_info,
	size_t overhead_bytes,
	Timestamp creation_time) {
	PacketFeedback packet;
	packet.creation_time = creation_time;
	packet.sent.sequence_number =
	seq_num_unwrapper_.Unwrap(packet_info.transport_sequence_number);
	packet.sent.size = DataSize::Bytes(packet_info.length + overhead_bytes);
	packet.sent.audio = packet_info.packet_type == RtpPacketMediaType::kAudio;
	packet.network_route = network_route_;
	packet.sent.pacing_info = packet_info.pacing_info;

	while (!history_.empty() &&
	creation_time - history_.begin()->second.creation_time >
	kSendTimeHistoryWindow) {
	// TODO(sprang): Warn if erasing (too many) old items?
	if (history_.begin()->second.sent.sequence_number > last_ack_seq_num_)
	in_flight_.RemoveInFlightPacketBytes(history_.begin()->second);
	history_.erase(history_.begin());
	}
	history_.insert(std::make_pair(packet.sent.sequence_number, packet));
	}

	absl::optional<SentPacket> TransportFeedbackAdapter::ProcessSentPacket(
	const rtc::SentPacket& sent_packet) {
	auto send_time = Timestamp::Millis(sent_packet.send_time_ms);
	// TODO(srte): Only use one way to indicate that packet feedback is used.
	if (sent_packet.info.included_in_feedback \|\| sent_packet.packet_id != -1) {
	int64_t unwrapped_seq_num =
	seq_num_unwrapper_.Unwrap(sent_packet.packet_id);
	auto it = history_.find(unwrapped_seq_num);
	if (it != history_.end()) {
	bool packet_retransmit = it->second.sent.send_time.IsFinite();
	it->second.sent.send_time = send_time;
	last_send_time_ = std::max(last_send_time_, send_time);
	// TODO(srte): Don't do this on retransmit.
	if (!pending_untracked_size_.IsZero()) {
	if (send_time < last_untracked_send_time_)
	RTC_LOG(LS_WARNING)
	<< "appending acknowledged data for out of order packet. (Diff: "
	<< ToString(last_untracked_send_time_ - send_time) << " ms.)";
	it->second.sent.prior_unacked_data += pending_untracked_size_;
	pending_untracked_size_ = DataSize::Zero();
	}
	if (!packet_retransmit) {
	if (it->second.sent.sequence_number > last_ack_seq_num_)
	in_flight_.AddInFlightPacketBytes(it->second);
	it->second.sent.data_in_flight = GetOutstandingData();
	return it->second.sent;
	}
	}
	} else if (sent_packet.info.included_in_allocation) {
	if (send_time < last_send_time_) {
	RTC_LOG(LS_WARNING) << "ignoring untracked data for out of order packet.";
	}
	pending_untracked_size_ +=
	DataSize::Bytes(sent_packet.info.packet_size_bytes);
	last_untracked_send_time_ = std::max(last_untracked_send_time_, send_time);
	}
	return absl::nullopt;
	}

	absl::optional<TransportPacketsFeedback>
	TransportFeedbackAdapter::ProcessTransportFeedback(
	const rtcp::TransportFeedback& feedback,
	Timestamp feedback_receive_time) {
	if (feedback.GetPacketStatusCount() == 0) {
	RTC_LOG(LS_INFO) << "Empty transport feedback packet received.";
	return absl::nullopt;
	}

	TransportPacketsFeedback msg;
	msg.feedback_time = feedback_receive_time;
	msg.packet_feedbacks =
	ProcessTransportFeedbackInner(feedback, feedback_receive_time);
	if (msg.packet_feedbacks.empty())
	return absl::nullopt;
	msg.data_in_flight = in_flight_.GetOutstandingData(network_route_);

	return msg;
	}

	void TransportFeedbackAdapter::SetNetworkRoute(
	const rtc::NetworkRoute& network_route) {
	network_route_ = network_route;
	}

	DataSize TransportFeedbackAdapter::GetOutstandingData() const {
	return in_flight_.GetOutstandingData(network_route_);
	}

	std::vector<PacketResult>
	TransportFeedbackAdapter::ProcessTransportFeedbackInner(
	const rtcp::TransportFeedback& feedback,
	Timestamp feedback_receive_time) {
	// Add timestamp deltas to a local time base selected on first packet arrival.
	// This won't be the true time base, but makes it easier to manually inspect
	// time stamps.
	if (last_timestamp_.IsInfinite()) {
	current_offset_ = feedback_receive_time;
	} else {
	// TODO(srte): We shouldn't need to do rounding here.
	const TimeDelta delta = feedback.GetBaseDelta(last_timestamp_)
	.RoundDownTo(TimeDelta::Millis(1));
	// Protect against assigning current_offset_ negative value.
	if (delta < Timestamp::Zero() - current_offset_) {
	RTC_LOG(LS_WARNING) << "Unexpected feedback timestamp received.";
	current_offset_ = feedback_receive_time;
	} else {
	current_offset_ += delta;
	}
	}
	last_timestamp_ = feedback.BaseTime();

	std::vector<PacketResult> packet_result_vector;
	packet_result_vector.reserve(feedback.GetPacketStatusCount());

	size_t failed_lookups = 0;
	size_t ignored = 0;

	feedback.ForAllPackets(
	[&](uint16_t sequence_number, TimeDelta delta_since_base) {
	int64_t seq_num = seq_num_unwrapper_.Unwrap(sequence_number);

	if (seq_num > last_ack_seq_num_) {
	// Starts at history_.begin() if last_ack_seq_num_ < 0, since any
	// valid sequence number is >= 0.
	for (auto it = history_.upper_bound(last_ack_seq_num_);
	it != history_.upper_bound(seq_num); ++it) {
	in_flight_.RemoveInFlightPacketBytes(it->second);
	}
	last_ack_seq_num_ = seq_num;
	}

	auto it = history_.find(seq_num);
	if (it == history_.end()) {
	++failed_lookups;
	return;
	}

	if (it->second.sent.send_time.IsInfinite()) {
	// TODO(srte): Fix the tests that makes this happen and make this a
	// DCHECK.
	RTC_DLOG(LS_ERROR)
	<< "Received feedback before packet was indicated as sent";
	return;
	}

	PacketFeedback packet_feedback = it->second;
	if (delta_since_base.IsFinite()) {
	packet_feedback.receive_time =
	current_offset_ +
	delta_since_base.RoundDownTo(TimeDelta::Millis(1));
	// Note: Lost packets are not removed from history because they might
	// be reported as received by a later feedback.
	history_.erase(it);
	}
	if (packet_feedback.network_route == network_route_) {
	PacketResult result;
	result.sent_packet = packet_feedback.sent;
	result.receive_time = packet_feedback.receive_time;
	packet_result_vector.push_back(result);
	} else {
	++ignored;
	}
	});

	if (failed_lookups > 0) {
	RTC_LOG(LS_WARNING)
	<< "Failed to lookup send time for " << failed_lookups << " packet"
	<< (failed_lookups > 1 ? "s" : "")
	<< ". Packets reordered or send time history too small?";
	}
	if (ignored > 0) {
	RTC_LOG(LS_INFO) << "Ignoring " << ignored
	<< " packets because they were sent on a different route.";
	}

	return packet_result_vector;
	}

	} // namespace webrtc