initial support to get CongestionControl down to Connection

libraries/networking/src/udt/CongestionControl.cpp

@@ -15,10 +15,9 @@
 
 using namespace udt;
 
-void UdtCC::init() {
+void DefaultCC::init() {
-    _rcInterval = _synInterval;
     _lastRCTime = usecTimestampNow();
-    setAckTimer(_rcInterval);
+    setAckTimer(synInterval());
     
     _lastAck = _sendCurrSeqNum;
     _lastDecSeq = SequenceNumber{ SequenceNumber::MAX };
@@ -27,7 +26,7 @@ void UdtCC::init() {
     _packetSendPeriod = 1.0;
 }
 
-void UdtCC::onACK(SequenceNumber ackNum) {
+void DefaultCC::onACK(SequenceNumber ackNum) {
     int64_t B = 0;
     double inc = 0;
     // Note: 1/24/2012
@@ -37,7 +36,7 @@ void UdtCC::onACK(SequenceNumber ackNum) {
     const double min_inc = 0.01;
     
     uint64_t currtime = usecTimestampNow();
-    if (currtime - _lastRCTime < (uint64_t)_rcInterval) {
+    if (currtime - _lastRCTime < (uint64_t)synInterval()) {
         return;
     }
     
@@ -52,11 +51,11 @@ void UdtCC::onACK(SequenceNumber ackNum) {
             if (_recvieveRate > 0) {
                 _packetSendPeriod = 1000000.0 / _recvieveRate;
             } else {
-                _packetSendPeriod = (_rtt + _rcInterval) / _congestionWindowSize;
+                _packetSendPeriod = (_rtt + synInterval()) / _congestionWindowSize;
             }
         }
     } else {
-        _congestionWindowSize = _recvieveRate / 1000000.0 * (_rtt + _rcInterval) + 16;
+        _congestionWindowSize = _recvieveRate / 1000000.0 * (_rtt + synInterval()) + 16;
     }
     
     // During Slow Start, no rate increase
@@ -86,10 +85,10 @@ void UdtCC::onACK(SequenceNumber ackNum) {
         }
     }
     
-    _packetSendPeriod = (_packetSendPeriod * _rcInterval) / (_packetSendPeriod * inc + _rcInterval);
+    _packetSendPeriod = (_packetSendPeriod * synInterval()) / (_packetSendPeriod * inc + synInterval());
 }
 
-void UdtCC::onLoss(const std::vector<SequenceNumber>& losslist) {
+void DefaultCC::onLoss(const std::vector<SequenceNumber>& losslist) {
     //Slow Start stopped, if it hasn't yet
     if (_slowStart) {
         _slowStart = false;
@@ -101,7 +100,7 @@ void UdtCC::onLoss(const std::vector<SequenceNumber>& losslist) {
         // If no receiving rate is observed, we have to compute the sending
         // rate according to the current window size, and decrease it
         // using the method below.
-        _packetSendPeriod = _congestionWindowSize / (_rtt + _rcInterval);
+        _packetSendPeriod = _congestionWindowSize / (_rtt + synInterval());
     }
     
     _loss = true;
@@ -128,13 +127,13 @@ void UdtCC::onLoss(const std::vector<SequenceNumber>& losslist) {
     }
 }
 
-void UdtCC::onTimeout() {
+void DefaultCC::onTimeout() {
     if (_slowStart) {
         _slowStart = false;
         if (_recvieveRate > 0) {
             _packetSendPeriod = 1000000.0 / _recvieveRate;
         } else {
-            _packetSendPeriod = _congestionWindowSize / (_rtt + _rcInterval);
+            _packetSendPeriod = _congestionWindowSize / (_rtt + synInterval());
         }
     } else {
         /*

libraries/networking/src/udt/CongestionControl.h

@@ -17,15 +17,19 @@
 #include "SequenceNumber.h"
 
 namespace udt {
+    
+static const int32_t DEFAULT_SYN_INTERVAL = 10000; // 10 ms
 
 class Packet;
 
 class CongestionControl {
 public:
-    static const int32_t DEFAULT_SYN_INTERVAL = 10000; // 10 ms
 
-    CongestionControl() {}
+    CongestionControl() {};
+    CongestionControl(int synInterval) : _synInterval(synInterval) {}
     virtual ~CongestionControl() {}
+    
+    int synInterval() const { return _synInterval; }
 
     virtual void init() {}
     virtual void close() {}
@@ -35,12 +39,10 @@ public:
     virtual void onPacketReceived(const Packet& packet) {}
     
 protected:
-    void setAckTimer(int syn) { _ackPeriod = (syn > _synInterval) ? _synInterval : syn; }
+    void setAckTimer(int period) { _ackPeriod = (period > _synInterval) ? _synInterval : period; }
-    void setAckInterval(int interval) { _ackInterval = interval; }
+    void setAckInterval(int ackInterval) { _ackInterval = ackInterval; }
     void setRto(int rto) { _userDefinedRto = true; _rto = rto; }
     
-    int32_t _synInterval = DEFAULT_SYN_INTERVAL; // UDT constant parameter, SYN
-    
     double _packetSendPeriod = 1.0; // Packet sending period, in microseconds
     double _congestionWindowSize = 16.0; // Congestion window size, in packets
     
@@ -66,6 +68,8 @@ private:
     int _ackPeriod = 0; // Periodical timer to send an ACK, in milliseconds
     int _ackInterval = 0; // How many packets to send one ACK, in packets
     
+    int _synInterval { DEFAULT_SYN_INTERVAL };
+    
     bool _userDefinedRto = false; // if the RTO value is defined by users
     int _rto = -1; // RTO value, microseconds
 };
@@ -75,6 +79,8 @@ class CongestionControlVirtualFactory {
 public:
     virtual ~CongestionControlVirtualFactory() {}
     
+    static int synInterval() { return DEFAULT_SYN_INTERVAL; }
+    
     virtual std::unique_ptr<CongestionControl> create() = 0;
 };
 
@@ -82,13 +88,12 @@ template <class T> class CongestionControlFactory: public CongestionControlVirtu
 {
 public:
     virtual ~CongestionControlFactory() {}
-    
     virtual std::unique_ptr<CongestionControl> create() { return std::unique_ptr<T>(new T()); }
 };
 
-class UdtCC: public CongestionControl {
+class DefaultCC: public CongestionControl {
 public:
-    UdtCC() {}
+    DefaultCC() {}
     
 public:
     virtual void init();
@@ -97,7 +102,6 @@ public:
     virtual void onTimeout();
     
 private:
-    int _rcInterval = 0;	// UDT Rate control interval
     uint64_t _lastRCTime = 0; // last rate increase time
     bool _slowStart = true;	// if in slow start phase
     SequenceNumber _lastAck; // last ACKed seq num
@@ -112,4 +116,4 @@ private:
     
 }
 
-#endif // hifi_CongestionControl_h
+#endif // hifi_CongestionControl_h

libraries/networking/src/udt/Connection.cpp

@@ -16,6 +16,7 @@
 #include <NumericalConstants.h>
 
 #include "../HifiSockAddr.h"
+#include "CongestionControl.h"
 #include "ControlPacket.h"
 #include "Packet.h"
 #include "Socket.h"
@@ -24,10 +25,12 @@ using namespace udt;
 using namespace std;
 using namespace std::chrono;
 
-Connection::Connection(Socket* parentSocket, HifiSockAddr destination) :
+Connection::Connection(Socket* parentSocket, HifiSockAddr destination, unique_ptr<CongestionControl> congestionControl) :
     _parentSocket(parentSocket),
-    _destination(destination)
+    _destination(destination),
+    _congestionControl(move(congestionControl))
 {
+    
 }
 
 Connection::~Connection() {
@@ -343,6 +346,7 @@ void Connection::processACK(std::unique_ptr<ControlPacket> controlPacket) {
     }
     
     // fire the onACK callback for congestion control
+    _congestionControl->onAck(ack);
     
     // update the total count of received ACKs
     ++_totalReceivedACKs;

libraries/networking/src/udt/Connection.h

@@ -22,6 +22,7 @@
 
 namespace udt {
     
+class CongestionControl;
 class ControlPacket;
 class Packet;
 class Socket;
@@ -32,7 +33,7 @@ public:
     using SequenceNumberTimePair = std::pair<SequenceNumber, std::chrono::high_resolution_clock::time_point>;
     using SentACKMap = std::unordered_map<SequenceNumber, SequenceNumberTimePair>;
     
-    Connection(Socket* parentSocket, HifiSockAddr destination);
+    Connection(Socket* parentSocket, HifiSockAddr destination, std::unique_ptr<CongestionControl> congestionControl);
     ~Connection();
     
     void sendReliablePacket(std::unique_ptr<Packet> packet);
@@ -89,6 +90,8 @@ private:
     
     std::unique_ptr<SendQueue> _sendQueue;
     
+    std::unique_ptr<CongestionControl> _congestionControl;
+    
     // Control Packet stat collection
     int _totalReceivedACKs { 0 };
     int _totalSentACKs { 0 };

libraries/networking/src/udt/Socket.cpp

@@ -79,7 +79,7 @@ qint64 Socket::writePacket(std::unique_ptr<Packet> packet, const HifiSockAddr& s
     if (packet->isReliable()) {
         auto it = _connectionsHash.find(sockAddr);
         if (it == _connectionsHash.end()) {
-            it = _connectionsHash.insert(it, std::make_pair(sockAddr, new Connection(this, sockAddr)));
+            it = _connectionsHash.insert(it, std::make_pair(sockAddr, new Connection(this, sockAddr, _ccFactory->create())));
         }
         it->second->sendReliablePacket(std::move(packet));
         return 0;
@@ -154,3 +154,11 @@ void Socket::rateControlSync() {
         _synTimer.start(_synInterval);
     }
 }
+
+void Socket::setCongestionControlFactory(std::unique_ptr<CongestionControlVirtualFactory> ccFactory) {
+    // swap the current unique_ptr for the new factory
+    _ccFactory.swap(ccFactory);
+    
+    // update the _synInterval to the value from the factory
+    _synInterval = _ccFactory->synInterval();
+}

libraries/networking/src/udt/Socket.h

@@ -22,6 +22,7 @@
 #include <QtNetwork/QUdpSocket>
 
 #include "../HifiSockAddr.h"
+#include "CongestionControl.h"
 #include "Connection.h"
 
 namespace udt {
@@ -59,6 +60,8 @@ public:
     
     void addUnfilteredHandler(const HifiSockAddr& senderSockAddr, BasePacketHandler handler)
         { _unfilteredHandlers[senderSockAddr] = handler; }
+    
+    void setCongestionControlFactory(std::unique_ptr<CongestionControlVirtualFactory> ccFactory);
 
 private slots:
     void readPendingDatagrams();
@@ -78,6 +81,8 @@ private:
     
     int32_t _synInterval = 10; // 10ms
     QTimer _synTimer;
+    
+    std::unique_ptr<CongestionControlVirtualFactory> _ccFactory { new CongestionControlFactory<DefaultCC>() };
 };
     
 } // namespace udt