[HICN-291] handle multiple paths in RTC

Change-Id: I69d331aa6e953e802e2f4b3e60325f852941fd94
Signed-off-by: michele papalini <micpapal@cisco.com>

1 files changed, 83 insertions, 8 deletions

diff --git a/libtransport/src/hicn/transport/protocols/rtc_data_path.cc b/libtransport/src/hicn/transport/protocols/rtc_data_path.cc
index 6c9605fb2..0cbff0e3c 100644
--- a/libtransport/src/hicn/transport/protocols/rtc_data_path.cc
+++ b/libtransport/src/hicn/transport/protocols/rtc_data_path.cc
@@ -14,6 +14,10 @@
  */
 
 #include <hicn/transport/protocols/rtc_data_path.h>
+#include <chrono>
+#include <cfloat>
+
+#define MAX_ROUNDS_WITHOUT_PKTS 10 //2sec
 
 namespace transport {
 
@@ -30,7 +34,13 @@ RTCDataPath::RTCDataPath()
                          // (for congestion/quality control)
       prev_min_owd(INT_MAX),
       avg_owd(0.0),
-      queuing_delay(0.0),
+      queuing_delay(DBL_MAX),
+      lastRecvSeq_(0),
+      lastRecvTime_(0),
+      avg_inter_arrival_(DBL_MAX),
+      received_nacks_(false),
+      received_packets_(false),
+      rounds_without_packets_(0),
       RTThistory_(HISTORY_LEN),
       OWDhistory_(HISTORY_LEN){};
 
@@ -43,14 +53,62 @@ void RTCDataPath::insertOwdSample(int64_t owd) {
   // for owd we use both min and avg
   if (owd < min_owd) min_owd = owd;
 
-  avg_owd = (avg_owd * (1 - ALPHA_RTC)) + (owd * ALPHA_RTC);
+  if(avg_owd != DBL_MAX)
+    avg_owd = (avg_owd * (1 - ALPHA_RTC)) + (owd * ALPHA_RTC);
+  else {
+    avg_owd = owd;
+  }
+
+  //owd is computed only for valid data packets so we count only
+  //this for decide if we recevie traffic or not
+  received_packets_ = true;
 }
 
-void RTCDataPath::roundEnd() {
-  // compute queuing delay
-  queuing_delay = avg_owd - getMinOwd();
+void RTCDataPath::computeInterArrivalGap(uint32_t segmentNumber){
+
+  //got packet in sequence, compute gap
+  if(lastRecvSeq_ == (segmentNumber - 1)){
+    uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(
+                      std::chrono::steady_clock::now().time_since_epoch())
+                      .count();
+    uint64_t delta = now - lastRecvTime_;
+    lastRecvSeq_ = segmentNumber;
+    lastRecvTime_ = now;
+    if(avg_inter_arrival_ == DBL_MAX)
+      avg_inter_arrival_ = delta;
+    else
+      avg_inter_arrival_ = (avg_inter_arrival_ * (1 -ALPHA_RTC))
+                                              + (delta * ALPHA_RTC);
+    return;
+  }
+
+  //ooo packet, update the stasts if needed
+  if(lastRecvSeq_ <= segmentNumber){
+    lastRecvSeq_ = segmentNumber;
+    lastRecvTime_ = std::chrono::duration_cast<std::chrono::milliseconds>(
+                      std::chrono::steady_clock::now().time_since_epoch())
+                      .count();
+  }
+}
+
+void RTCDataPath::receivedNack(){
+  received_nacks_ = true;
+}
+
+double RTCDataPath::getInterArrivalGap(){
+  if(avg_inter_arrival_ == DBL_MAX)
+    return 0;
+  return avg_inter_arrival_;
+}
+
+bool RTCDataPath::isActive(){
+  if(received_nacks_ && rounds_without_packets_ < MAX_ROUNDS_WITHOUT_PKTS)
+    return true;
+  return false;
+}
 
-  // reset min_rtt and add it to the history
+void RTCDataPath::roundEnd() {
+   // reset min_rtt and add it to the history
   if (min_rtt != UINT_MAX) {
     prev_min_rtt = min_rtt;
   } else {
@@ -60,6 +118,9 @@ void RTCDataPath::roundEnd() {
     min_rtt = prev_min_rtt;
   }
 
+  if(min_rtt == 0)
+    min_rtt = 1;
+
   RTThistory_.pushBack(min_rtt);
   min_rtt = UINT_MAX;
 
@@ -70,8 +131,22 @@ void RTCDataPath::roundEnd() {
     min_owd = prev_min_owd;
   }
 
-  OWDhistory_.pushBack(min_owd);
-  min_owd = INT_MAX;
+  if (min_owd != INT_MAX) {
+    OWDhistory_.pushBack(min_owd);
+    min_owd = INT_MAX;
+
+    // compute queuing delay
+    queuing_delay = avg_owd - getMinOwd();
+
+  } else {
+    queuing_delay = 0.0;
+  }
+
+  if(!received_packets_)
+    rounds_without_packets_++;
+  else
+    rounds_without_packets_ = 0;
+  received_packets_ = false;
 }
 
 double RTCDataPath::getQueuingDealy() { return queuing_delay; }