first commit for srt intergrate

srt/Statistic.cpp

@@ -0,0 +1,76 @@
+#include <algorithm>
+
+#include "Statistic.hpp"
+namespace SRT {
+void PacketRecvRateContext::inputPacket(TimePoint ts) {
+   if(_pkt_map.size()>100){
+       _pkt_map.erase(_pkt_map.begin());
+   }
+   _pkt_map.emplace(ts,ts);
+}
+uint32_t PacketRecvRateContext::getPacketRecvRate() {
+    if(_pkt_map.size()<2){
+        return 0;
+    }
+
+    auto first = _pkt_map.begin();
+    auto last = _pkt_map.rbegin();
+    double dur = DurationCountMicroseconds(last->first - first->first)/1000000.0;
+    double rate = _pkt_map.size()/dur;
+    return (uint32_t)rate;
+}
+
+void EstimatedLinkCapacityContext::inputPacket(TimePoint ts) {
+    if(_pkt_map.size()>16){
+        _pkt_map.erase(_pkt_map.begin());
+    }
+     _pkt_map.emplace(ts,ts);
+}
+uint32_t EstimatedLinkCapacityContext::getEstimatedLinkCapacity() {
+   decltype(_pkt_map.begin()) next;
+   std::vector<SteadyClock::duration> tmp;
+
+   for(auto it = _pkt_map.begin();it != _pkt_map.end();++it){
+       next = it;
+       ++next;
+       if(next != _pkt_map.end()){
+           tmp.push_back(next->first -it->first);
+       }else{
+           break;
+       }
+   }
+   std::sort(tmp.begin(),tmp.end());
+   if(tmp.empty()){
+       return 0;
+   }
+
+   double dur =DurationCountMicroseconds(tmp[tmp.size()/2])/1e6;
+
+   return  (uint32_t)(1.0/dur);
+
+}
+
+void RecvRateContext::inputPacket(TimePoint ts, size_t size ) {
+    if (_pkt_map.size() > 100) {
+        _pkt_map.erase(_pkt_map.begin());
+    }
+    _pkt_map.emplace(ts, size);
+}
+uint32_t RecvRateContext::getRecvRate() {
+    if(_pkt_map.size()<2){
+        return 0;
+    }
+
+    auto first = _pkt_map.begin();
+    auto last = _pkt_map.rbegin();
+    double dur = DurationCountMicroseconds(last->first - first->first)/1000000.0;
+
+    size_t bytes = 0;
+    for(auto it : _pkt_map){
+        bytes += it.second;
+    }
+    double rate = (double)bytes/dur;
+    return (uint32_t)rate;
+}
+
+} // namespace SRT