add output of connection stats in UDTTest

libraries/networking/src/udt/Connection.cpp

@@ -126,9 +126,17 @@ void Connection::sendACK(bool wasCausedBySyncTimeout) {
     ackPacket->writePrimitive((int32_t) udt::CONNECTION_RECEIVE_BUFFER_SIZE_PACKETS);
     
     if (wasCausedBySyncTimeout) {
+        // grab the up to date packet receive speed and estimated bandwidth
+        int32_t packetReceiveSpeed = _receiveWindow.getPacketReceiveSpeed();
+        int32_t estimatedBandwidth = _receiveWindow.getEstimatedBandwidth();
+        
+        // update those values in our connection stats
+        _stats.recordReceiveRate(packetReceiveSpeed);
+        _stats.recordEstimatedBandwidth(estimatedBandwidth);
+        
         // pack in the receive speed and estimatedBandwidth
-        ackPacket->writePrimitive(_receiveWindow.getPacketReceiveSpeed());
+        ackPacket->writePrimitive(packetReceiveSpeed);
-        ackPacket->writePrimitive(_receiveWindow.getEstimatedBandwidth());
+        ackPacket->writePrimitive(estimatedBandwidth);
         
         // record this as the last ACK send time
         lastACKSendTime = high_resolution_clock::now();
@@ -261,6 +269,7 @@ bool Connection::processReceivedSequenceNumber(SequenceNumber sequenceNumber) {
         _nakInterval = (_rtt + 4 * _rttVariance);
         
         int receivedPacketsPerSecond = _receiveWindow.getPacketReceiveSpeed();
+        
         if (receivedPacketsPerSecond > 0) {
             // the NAK interval is at least the _minNAKInterval
             // but might be the time required for all lost packets to be retransmitted
@@ -371,10 +380,12 @@ void Connection::processACK(std::unique_ptr<ControlPacket> controlPacket) {
     // ACK the send queue so it knows what was received
     _sendQueue->ack(ack);
     
-    
     // update the RTT
     updateRTT(rtt);
     
+    // write this RTT to stats
+    _stats.recordRTT(rtt);
+    
     // set the RTT for congestion control
     _congestionControl->setRTT(_rtt);
     
@@ -387,6 +398,10 @@ void Connection::processACK(std::unique_ptr<ControlPacket> controlPacket) {
         // these are calculated using an EWMA
         static const int EMWA_ALPHA_NUMERATOR = 8;
         
+        // record these samples in connection stats
+        _stats.recordReceiveRate(receiveRate);
+        _stats.recordEstimatedBandwidth(bandwidth);
+        
         _deliveryRate = (_deliveryRate * (EMWA_ALPHA_NUMERATOR - 1) + _deliveryRate) / EMWA_ALPHA_NUMERATOR;
         _bandwidth = (_bandwidth * (EMWA_ALPHA_NUMERATOR - 1) + _bandwidth) / EMWA_ALPHA_NUMERATOR;
         
@@ -515,4 +530,8 @@ void Connection::updateCongestionControlAndSendQueue(std::function<void ()> cong
     // now that we've update the congestion control, update the packet send period and flow window size
     _sendQueue->setPacketSendPeriod(_congestionControl->_packetSendPeriod);
     _sendQueue->setFlowWindowSize(std::min(_flowWindowSize, (int) _congestionControl->_congestionWindowSize));
+    
+    // record connection stats
+    _stats.recordPacketSendPeriod(_congestionControl->_packetSendPeriod);
+    _stats.recordCongestionWindowSize(_congestionControl->_congestionWindowSize);
 }

libraries/networking/src/udt/Connection.h

@@ -46,6 +46,8 @@ public:
     
     bool processReceivedSequenceNumber(SequenceNumber sequenceNumber); // returns indicates if this packet was a duplicate
     void processControl(std::unique_ptr<ControlPacket> controlPacket);
+    
+    ConnectionStats::Stats sampleStats() { return _stats.sample(); }
 
 signals:
     void packetSent();

libraries/networking/src/udt/ConnectionStats.cpp

@@ -89,4 +89,32 @@ void ConnectionStats::recordSentPackets() {
 void ConnectionStats::recordReceivedPackets() {
     ++_currentSample.recievedPackets;
     ++_total.recievedPackets;
-}
+}
+
+static const double EWMA_CURRENT_SAMPLE_WEIGHT = 0.125;
+static const double EWMA_PREVIOUS_SAMPLES_WEIGHT = 1 - 0.125;
+
+void ConnectionStats::recordReceiveRate(int sample) {
+    _currentSample.receiveRate = sample;
+    _total.receiveRate = (_total.receiveRate * EWMA_PREVIOUS_SAMPLES_WEIGHT) + (sample * EWMA_CURRENT_SAMPLE_WEIGHT);
+}
+
+void ConnectionStats::recordEstimatedBandwidth(int sample) {
+    _currentSample.estimatedBandwith = sample;
+    _total.estimatedBandwith = (_total.estimatedBandwith * EWMA_PREVIOUS_SAMPLES_WEIGHT) + (sample * EWMA_CURRENT_SAMPLE_WEIGHT);
+}
+
+void ConnectionStats::recordRTT(int sample) {
+    _currentSample.rtt = sample;
+    _total.rtt = (_total.rtt * EWMA_PREVIOUS_SAMPLES_WEIGHT) + (sample * EWMA_CURRENT_SAMPLE_WEIGHT);
+}
+
+void ConnectionStats::recordCongestionWindowSize(int sample) {
+    _currentSample.congestionWindowSize = sample;
+    _total.congestionWindowSize = (_total.congestionWindowSize * EWMA_PREVIOUS_SAMPLES_WEIGHT) + (sample * EWMA_CURRENT_SAMPLE_WEIGHT);
+}
+
+void ConnectionStats::recordPacketSendPeriod(int sample) {
+    _currentSample.packetSendPeriod = sample;
+    _total.packetSendPeriod = (_total.packetSendPeriod * EWMA_PREVIOUS_SAMPLES_WEIGHT) + (sample * EWMA_CURRENT_SAMPLE_WEIGHT);
+}

libraries/networking/src/udt/ConnectionStats.h

@@ -36,6 +36,13 @@ public:
         
         int sentPackets { 0 };
         int recievedPackets { 0 };
+       
+        // the following stats are trailing averages in the result, not totals
+        int receiveRate { 0 };
+        int estimatedBandwith { 0 };
+        int rtt { 0 };
+        int congestionWindowSize { 0 };
+        int packetSendPeriod { 0 };
     };
     
     ConnectionStats();
@@ -57,6 +64,12 @@ public:
     void recordSentPackets();
     void recordReceivedPackets();
     
+    void recordReceiveRate(int sample);
+    void recordEstimatedBandwidth(int sample);
+    void recordRTT(int sample);
+    void recordCongestionWindowSize(int sample);
+    void recordPacketSendPeriod(int sample);
+    
 private:
     Stats _currentSample;
     Stats _total;
@@ -64,4 +77,4 @@ private:
     
 }
 
-#endif // hifi_ConnectionStats_h
+#endif // hifi_ConnectionStats_h

libraries/networking/src/udt/Socket.cpp

@@ -213,3 +213,20 @@ void Socket::setCongestionControlFactory(std::unique_ptr<CongestionControlVirtua
     // update the _synInterval to the value from the factory
     _synInterval = _ccFactory->synInterval();
 }
+
+void Socket::sampleAndPrintConnectionStats() {
+    if (thread() != QThread::currentThread()) {
+        QMetaObject::invokeMethod(this, "sampleAndPrintConnectionStats");
+        return;
+    }
+    
+    for(auto& connection : _connectionsHash) {
+        ConnectionStats::Stats sampleStats = connection.second->sampleStats();
+        
+        qDebug() << connection.first
+            << sampleStats.receiveRate << sampleStats.rtt
+            << sampleStats.congestionWindowSize << sampleStats.packetSendPeriod
+            << sampleStats.sentPackets
+            << sampleStats.receivedACKs << sampleStats.receivedLightACKs << sampleStats.receivedNAKs;
+    }
+}

libraries/networking/src/udt/Socket.h

@@ -63,6 +63,8 @@ public:
     void setCongestionControlFactory(std::unique_ptr<CongestionControlVirtualFactory> ccFactory);
     
     void connectToSendSignal(const HifiSockAddr& destinationAddr, QObject* receiver, const char* slot);
+    
+    void sampleAndPrintConnectionStats();
 
 private slots:
     void readPendingDatagrams();

tools/udt-test/src/UDTTest.cpp

@@ -116,6 +116,13 @@ UDTTest::UDTTest(int& argc, char** argv) :
     
     if (!_target.isNull()) {
         sendInitialPackets();
+        
+        // the sender reports stats every 1 second
+        static const int STATS_SAMPLE_INTERVAL = 1000;
+        
+        QTimer* statsTimer = new QTimer(this);
+        connect(statsTimer, &QTimer::timeout, this, &UDTTest::sampleStats);
+        statsTimer->start(STATS_SAMPLE_INTERVAL);
     }
 }
 
@@ -198,3 +205,7 @@ void UDTTest::sendPacket() {
     
     ++_totalQueuedPackets;
 }
+
+void UDTTest::sampleStats() {
+    _socket.sampleAndPrintConnectionStats();
+}

tools/udt-test/src/UDTTest.h

@@ -27,6 +27,7 @@ public:
 
 public slots:
     void refillPacket() { sendPacket(); } // adds a new packet to the queue when we are told one is sent
+    void sampleStats();
     
 private:
     void parseArguments();