flowmonitor: (fixes #901) allow to reset the stats

CHANGES.md

@@ -25,6 +25,7 @@ Changes from ns-3.38 to ns-3-dev
 * (lr-wpan) Added `LrwpanMac::MlmeGetRequest` function and the corresponding confirm callbacks as well as `LrwpanMac::SetMlmeGetConfirm` function.
 * (applications) Added `Tx` and `TxWithAddresses` trace sources in `UdpClient`.
 * (stats) Added `Histogram::Clear` function to clear the histogram contents.
+* (flow-monitor) Added `FlowMonitor::ResetAllStats` function to reset the FlowMonitor statistics.
 
 ### Changes to existing API
 

src/flow-monitor/model/flow-monitor.cc

@@ -534,4 +534,31 @@ FlowMonitor::SerializeToXmlFile(std::string fileName, bool enableHistograms, boo
     os.close();
 }
 
+void
+FlowMonitor::ResetAllStats()
+{
+    NS_LOG_FUNCTION(this);
+
+    for (auto& iter : m_flowStats)
+    {
+        auto& flowStat = iter.second;
+        flowStat.delaySum = Seconds(0);
+        flowStat.jitterSum = Seconds(0);
+        flowStat.lastDelay = Seconds(0);
+        flowStat.txBytes = 0;
+        flowStat.rxBytes = 0;
+        flowStat.txPackets = 0;
+        flowStat.rxPackets = 0;
+        flowStat.lostPackets = 0;
+        flowStat.timesForwarded = 0;
+        flowStat.bytesDropped.clear();
+        flowStat.packetsDropped.clear();
+
+        flowStat.delayHistogram.Clear();
+        flowStat.jitterHistogram.Clear();
+        flowStat.packetSizeHistogram.Clear();
+        flowStat.flowInterruptionsHistogram.Clear();
+    }
+}
+
 } // namespace ns3

src/flow-monitor/model/flow-monitor.h

@@ -273,6 +273,9 @@ class FlowMonitor : public Object
     /// \param enableProbes if true, include also the per-probe/flow pair statistics in the output
     void SerializeToXmlFile(std::string fileName, bool enableHistograms, bool enableProbes);
 
+    /// Reset all the statistics
+    void ResetAllStats();
+
   protected:
     void NotifyConstructionCompleted() override;
     void DoDispose() override;