GetTransportFeedbackVector() includes unreceived packets, sorted by seq-num

webrtc/modules/congestion_controller/transport_feedback_adapter_unittest.cc

 /*
  *  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.
  */
 
@@ skipping 72 matching lines @@
     // truth contains the input data for the test, and input is what will be
     // sent to the bandwidth estimator. truth.arrival_tims_ms is used to
     // populate the transport feedback messages. As these times may be changed
     // (because of resolution limits in the packets, and because of the time
     // base adjustment performed by the TransportFeedbackAdapter at the first
     // packet, the truth[x].arrival_time and input[x].arrival_time may not be
     // equal. However, the difference must be the same for all x.
     int64_t arrival_time_delta =
         truth[0].arrival_time_ms - input[0].arrival_time_ms;
     for (size_t i = 0; i < len; ++i) {
-      EXPECT_EQ(truth[i].arrival_time_ms,
-                input[i].arrival_time_ms + arrival_time_delta);
+      RTC_CHECK(truth[i].arrival_time_ms != PacketFeedback::kNotReceived);
+      if (input[i].arrival_time_ms != PacketFeedback::kNotReceived) {
+        EXPECT_EQ(truth[i].arrival_time_ms,
+                  input[i].arrival_time_ms + arrival_time_delta);
+      }
       EXPECT_EQ(truth[i].send_time_ms, input[i].send_time_ms);
       EXPECT_EQ(truth[i].sequence_number, input[i].sequence_number);
       EXPECT_EQ(truth[i].payload_size, input[i].payload_size);
       EXPECT_EQ(truth[i].pacing_info, input[i].pacing_info);
     }
   }
 
   void OnSentPacket(const PacketFeedback& packet_feedback) {
     adapter_->AddPacket(packet_feedback.sequence_number,
                         packet_feedback.payload_size,
@@ skipping 28 matching lines @@
     EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
                                            packet.arrival_time_ms * 1000));
   }
 
   feedback.Build();
 
   adapter_->OnTransportFeedback(feedback);
   ComparePacketVectors(packets, adapter_->GetTransportFeedbackVector());
 }
 
+TEST_F(TransportFeedbackAdapterTest, FeedbackVectorReportsUnreceived) {
+  std::vector<PacketFeedback> sent_packets = {
+      PacketFeedback(100, 220, 0, 1500, kPacingInfo0),
+      PacketFeedback(110, 210, 1, 1500, kPacingInfo0),
+      PacketFeedback(120, 220, 2, 1500, kPacingInfo0),
+      PacketFeedback(130, 230, 3, 1500, kPacingInfo0),
+      PacketFeedback(140, 240, 4, 1500, kPacingInfo0),
+      PacketFeedback(150, 250, 5, 1500, kPacingInfo0),
+      PacketFeedback(160, 260, 6, 1500, kPacingInfo0)
+  };
+
+  for (const PacketFeedback& packet : sent_packets)
+    OnSentPacket(packet);
+
+  // Note: Important to include the last packet, as only unreceived packets in
+  // between received packets can be inferred.
+  std::vector<PacketFeedback> received_packets = {
+    sent_packets[0], sent_packets[2], sent_packets[6]
+  };
+
+  rtcp::TransportFeedback feedback;
+  feedback.SetBase(received_packets[0].sequence_number,
+                   received_packets[0].arrival_time_ms * 1000);
+
+  for (const PacketFeedback& packet : received_packets) {
+    EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
+                                           packet.arrival_time_ms * 1000));
+  }
+
+  feedback.Build();
+
+  adapter_->OnTransportFeedback(feedback);
+  ComparePacketVectors(sent_packets, adapter_->GetTransportFeedbackVector());
+}
+
 TEST_F(TransportFeedbackAdapterTest, LongFeedbackDelays) {
   const int64_t kFeedbackTimeoutMs = 60001;
   const int kMaxConsecutiveFailedLookups = 5;
   for (int i = 0; i < kMaxConsecutiveFailedLookups; ++i) {
     std::vector<PacketFeedback> packets;
     packets.push_back(
         PacketFeedback(i * 100, 2 * i * 100, 0, 1500, kPacingInfo0));
     packets.push_back(
         PacketFeedback(i * 100 + 10, 2 * i * 100 + 10, 1, 1500, kPacingInfo0));
     packets.push_back(
@@ skipping 145 matching lines @@
 
     std::vector<PacketFeedback> expected_packets;
     expected_packets.push_back(packets[i]);
 
     adapter_->OnTransportFeedback(*feedback.get());
     ComparePacketVectors(expected_packets,
                          adapter_->GetTransportFeedbackVector());
   }
 }
 
-TEST_F(TransportFeedbackAdapterTest, HandlesReordering) {
+TEST_F(TransportFeedbackAdapterTest, HandlesArrivalReordering) {
   std::vector<PacketFeedback> packets;
   packets.push_back(PacketFeedback(120, 200, 0, 1500, kPacingInfo0));
   packets.push_back(PacketFeedback(110, 210, 1, 1500, kPacingInfo0));
   packets.push_back(PacketFeedback(100, 220, 2, 1500, kPacingInfo0));
-  std::vector<PacketFeedback> expected_packets;
-  expected_packets.push_back(packets[2]);
-  expected_packets.push_back(packets[1]);
-  expected_packets.push_back(packets[0]);
 
   for (const PacketFeedback& packet : packets)
     OnSentPacket(packet);
 
   rtcp::TransportFeedback feedback;
   feedback.SetBase(packets[0].sequence_number,
                    packets[0].arrival_time_ms * 1000);
 
   for (const PacketFeedback& packet : packets) {
     EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
                                            packet.arrival_time_ms * 1000));
   }
 
   feedback.Build();
 
+  // Adapter keeps the packets ordered by sequence number (which is itself
+  // assigned by the order of transmission). Reordering by some other criteria,
+  // eg. arrival time, is up to the observers.
   adapter_->OnTransportFeedback(feedback);
-  ComparePacketVectors(expected_packets,
-                       adapter_->GetTransportFeedbackVector());
+  ComparePacketVectors(packets, adapter_->GetTransportFeedbackVector());
 }
 
 TEST_F(TransportFeedbackAdapterTest, TimestampDeltas) {
   std::vector<PacketFeedback> sent_packets;
   const int64_t kSmallDeltaUs =
       rtcp::TransportFeedback::kDeltaScaleFactor * ((1 << 8) - 1);
   const int64_t kLargePositiveDeltaUs =
       rtcp::TransportFeedback::kDeltaScaleFactor *
       std::numeric_limits<int16_t>::max();
   const int64_t kLargeNegativeDeltaUs =
@@ skipping 42 matching lines @@
       packet_feedback.sequence_number, packet_feedback.arrival_time_ms * 1000));
 
   rtc::Buffer raw_packet = feedback->Build();
   feedback =
       rtcp::TransportFeedback::ParseFrom(raw_packet.data(), raw_packet.size());
 
   std::vector<PacketFeedback> received_feedback;
 
   EXPECT_TRUE(feedback.get() != nullptr);
   adapter_->OnTransportFeedback(*feedback.get());
-  {
-    // Expected to be ordered on arrival time when the feedback message has been
-    // parsed.
-    std::vector<PacketFeedback> expected_packets;
-    expected_packets.push_back(sent_packets[0]);
-    expected_packets.push_back(sent_packets[3]);
-    expected_packets.push_back(sent_packets[1]);
-    expected_packets.push_back(sent_packets[2]);
-    ComparePacketVectors(expected_packets,
-                         adapter_->GetTransportFeedbackVector());
-  }
+  ComparePacketVectors(sent_packets, adapter_->GetTransportFeedbackVector());
 
   // Create a new feedback message and add the trailing item.
   feedback.reset(new rtcp::TransportFeedback());
   feedback->SetBase(packet_feedback.sequence_number,
                     packet_feedback.arrival_time_ms * 1000);
   EXPECT_TRUE(feedback->AddReceivedPacket(
       packet_feedback.sequence_number, packet_feedback.arrival_time_ms * 1000));
   raw_packet = feedback->Build();
   feedback =
       rtcp::TransportFeedback::ParseFrom(raw_packet.data(), raw_packet.size());
@@ skipping 32 matching lines @@
     EXPECT_TRUE(feedback.get() != nullptr);
     adapter_->OnTransportFeedback(*feedback.get());
     clock_.AdvanceTimeMilliseconds(50);
     ++seq_num;
   }
   EXPECT_GT(target_bitrate_bps_, 0u);
 }
 
 }  // namespace test
 }  // namespace webrtc