From 5fc3e7dbf1b19a3ef518d564b29a30b411807d0c Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Wed, 29 Jul 2015 16:12:00 -0700
Subject: [PATCH] add an updater that takes a lambda for CC update

---
 libraries/networking/src/udt/Connection.cpp | 38 +++++++++++----------
 libraries/networking/src/udt/Connection.h   |  2 ++
 2 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/libraries/networking/src/udt/Connection.cpp b/libraries/networking/src/udt/Connection.cpp
index 935622f4d8..626833c5c5 100644
--- a/libraries/networking/src/udt/Connection.cpp
+++ b/libraries/networking/src/udt/Connection.cpp
@@ -383,15 +383,10 @@ void Connection::processACK(std::unique_ptr<ControlPacket> controlPacket) {
         _congestionControl->setBandwidth(_bandwidth);
     }
     
-    // update the last sent sequence number in congestion control
-    _congestionControl->setSendCurrentSequenceNumber(_sendQueue->getCurrentSequenceNumber());
-    
-    // fire the onACK callback for congestion control
-    _congestionControl->onAck(ack);
-    
-    // now that we've updated the congestion control, update the packet send period and flow window size
-    _sendQueue->setPacketSendPeriod(_congestionControl->_packetSendPeriod);
-    _sendQueue->setFlowWindowSize(std::min(_flowWindowSize, (int) _congestionControl->_congestionWindowSize));
+    // give this ACK to the congestion control and update the send queue parameters
+    updateCongestionControlAndSentQueue([this, ack](){
+        _congestionControl->onAck(ack);
+    });
     
     // update the total count of received ACKs
     _stats.recordReceivedACK();
@@ -457,15 +452,10 @@ void Connection::processNAK(std::unique_ptr<ControlPacket> controlPacket) {
     // send that off to the send queue so it knows there was loss
     _sendQueue->nak(start, end);
     
-    // update the last sent sequence number in congestion control
-    _congestionControl->setSendCurrentSequenceNumber(_sendQueue->getCurrentSequenceNumber());
-    
-    // give the loss to the congestion control object
-    _congestionControl->onLoss(start, end);
-    
-    // now that we've updated the congestion control, update the packet send period and flow window size
-    _sendQueue->setPacketSendPeriod(_congestionControl->_packetSendPeriod);
-    _sendQueue->setFlowWindowSize(std::min(_flowWindowSize, (int) _congestionControl->_congestionWindowSize));
+    // give the loss to the congestion control object and update the send queue parameters
+    updateCongestionControlAndSentQueue([this, start, end](){
+        _congestionControl->onLoss(start, end);
+    });
     
     _stats.recordReceivedNAK();
 }
@@ -503,3 +493,15 @@ void Connection::updateRTT(int rtt) {
 int Connection::estimatedTimeout() const {
     return _congestionControl->_userDefinedRto ? _rtt + _rttVariance * 4 : _congestionControl->_rto;
 }
+
+void Connection::updateCongestionControlAndSentQueue(std::function<void ()> congestionCallback) {
+    // update the last sent sequence number in congestion control
+    _congestionControl->setSendCurrentSequenceNumber(_sendQueue->getCurrentSequenceNumber());
+    
+    // fire congestion control callback
+    congestionCallback();
+    
+    // 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));
+}
diff --git a/libraries/networking/src/udt/Connection.h b/libraries/networking/src/udt/Connection.h
index 1ce81734b2..b46d2c37cf 100644
--- a/libraries/networking/src/udt/Connection.h
+++ b/libraries/networking/src/udt/Connection.h
@@ -64,6 +64,8 @@ private:
     
     int estimatedTimeout() const;
     
+    void updateCongestionControlAndSentQueue(std::function<void()> congestionCallback);
+    
     int _synInterval; // Periodical Rate Control Interval, in microseconds
     
     int _nakInterval; // NAK timeout interval, in microseconds