From 666ef50459c70f022f8e3dccf5f3d4fb3759f7c9 Mon Sep 17 00:00:00 2001
From: Per K <perkj@webrtc.org>
Date: Wed, 3 Jul 2024 06:32:40 +0000
Subject: [PATCH] Plot reordered packets since last feedback.
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Bug: None
Change-Id: I528227980a9e2a88593e891f702ad44ee5b9d7fa
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/356041
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Commit-Queue: Per Kjellander <perkj@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42578}
---
 .../rtc_event_log_visualizer/analyzer.cc      | 45 +++++++++++++++----
 1 file changed, 37 insertions(+), 8 deletions(-)

diff --git a/rtc_tools/rtc_event_log_visualizer/analyzer.cc b/rtc_tools/rtc_event_log_visualizer/analyzer.cc
index 0b882f4289..62868ff839 100644
--- a/rtc_tools/rtc_event_log_visualizer/analyzer.cc
+++ b/rtc_tools/rtc_event_log_visualizer/analyzer.cc
@@ -20,6 +20,7 @@
 #include <memory>
 #include <string>
 #include <tuple>
+#include <unordered_set>
 #include <utility>
 #include <vector>
 
@@ -1538,6 +1539,9 @@ void EventLogAnalyzer::CreateGoogCcSimulationGraph(Plot* plot) {
 void EventLogAnalyzer::CreateOutgoingTWCCLossRateGraph(Plot* plot) {
   TimeSeries loss_rate_series("Loss rate (from packet feedback)",
                               LineStyle::kLine, PointStyle::kHighlight);
+  TimeSeries reordered_packets_between_feedback(
+      "Ratio of reordered packets from last feedback", LineStyle::kLine,
+      PointStyle::kHighlight);
   TimeSeries average_loss_rate_series("Average loss rate last 5s",
                                       LineStyle::kLine, PointStyle::kHighlight);
   TimeSeries missing_feedback_series("Missing feedback", LineStyle::kNone,
@@ -1556,27 +1560,49 @@ void EventLogAnalyzer::CreateOutgoingTWCCLossRateGraph(Plot* plot) {
         unwrapper.Unwrap(parsed_log_.transport_feedbacks(kIncomingPacket)[0]
                              .transport_feedback.GetBaseSequence());
   }
+  std::unordered_set<int64_t> previous_feedback_lost_sequence_numbers;
+  size_t previous_feedback_size = 0;
   for (auto& feedback : parsed_log_.transport_feedbacks(kIncomingPacket)) {
     const rtcp::TransportFeedback& transport_feedback =
         feedback.transport_feedback;
-    size_t base_seq_num =
+    int64_t base_seq_num =
         unwrapper.Unwrap(transport_feedback.GetBaseSequence());
     // Collect packets that do not have feedback, which are from the last acked
     // packet, to the current base packet.
-    for (size_t seq_num = last_acked; seq_num < base_seq_num; ++seq_num) {
+    for (int64_t seq_num = last_acked; seq_num < base_seq_num; ++seq_num) {
       missing_feedback_series.points.emplace_back(
           config_.GetCallTimeSec(feedback.timestamp),
           100 + seq_num - last_acked);
     }
     last_acked = base_seq_num + transport_feedback.GetPacketStatusCount();
 
+    int num_reordered_packets = 0;
+    std::unordered_set<int64_t> lost_sequence_numbers;
+    transport_feedback.ForAllPackets(
+        [&](uint16_t sequence_number, TimeDelta receive_time_delta) {
+          int64_t unwrapped_seq = unwrapper.Unwrap(sequence_number);
+          if (receive_time_delta.IsInfinite()) {
+            lost_sequence_numbers.insert(unwrapped_seq);
+          } else {
+            num_reordered_packets +=
+                previous_feedback_lost_sequence_numbers.count(unwrapped_seq);
+          }
+        });
+
     // Compute loss rate from the transport feedback.
-    auto loss_rate =
-        static_cast<float>((transport_feedback.GetPacketStatusCount() -
-                            transport_feedback.GetReceivedPackets().size()) *
-                           100.0 / transport_feedback.GetPacketStatusCount());
+    float loss_rate =
+        static_cast<float>(lost_sequence_numbers.size() * 100.0 /
+                           transport_feedback.GetPacketStatusCount());
+
     loss_rate_series.points.emplace_back(
         config_.GetCallTimeSec(feedback.timestamp), loss_rate);
+    float reordered_rate =
+        previous_feedback_size == 0
+            ? 0
+            : static_cast<float>(num_reordered_packets * 100.0 /
+                                 previous_feedback_size);
+    reordered_packets_between_feedback.points.emplace_back(
+        config_.GetCallTimeSec(feedback.timestamp), reordered_rate);
 
     // Compute loss rate in a window of kObservationWindowSize.
     if (window_summary.num_packets == 0) {
@@ -1584,8 +1610,7 @@ void EventLogAnalyzer::CreateOutgoingTWCCLossRateGraph(Plot* plot) {
     }
     window_summary.num_packets += transport_feedback.GetPacketStatusCount();
     window_summary.num_lost_packets +=
-        transport_feedback.GetPacketStatusCount() -
-        transport_feedback.GetReceivedPackets().size();
+        lost_sequence_numbers.size() - num_reordered_packets;
 
     const Timestamp last_received_time = feedback.log_time();
     const TimeDelta observation_duration =
@@ -1616,9 +1641,13 @@ void EventLogAnalyzer::CreateOutgoingTWCCLossRateGraph(Plot* plot) {
       }
       window_summary = PacketLossSummary();
     }
+    std::swap(previous_feedback_lost_sequence_numbers, lost_sequence_numbers);
+    previous_feedback_size = transport_feedback.GetPacketStatusCount();
   }
   // Add the data set to the plot.
   plot->AppendTimeSeriesIfNotEmpty(std::move(loss_rate_series));
+  plot->AppendTimeSeriesIfNotEmpty(
+      std::move(reordered_packets_between_feedback));
   plot->AppendTimeSeriesIfNotEmpty(std::move(average_loss_rate_series));
   plot->AppendTimeSeriesIfNotEmpty(std::move(missing_feedback_series));