add metric test

CMakeLists.txt

@@ -90,6 +90,7 @@ add_executable(unit-tests
         tests/test_parse_pcap.cpp
         tests/test_sketches.cpp
         tests/test_utils.cpp
+        tests/test_metrics.cpp
         )
 
 if (MMDB_ENABLE)

src/metrics.cpp

@@ -165,7 +165,8 @@ void Metrics::newDNSPacket(pcpp::DnsLayer *dns, Direction dir, pcpp::ProtocolTyp
         auto aggDomain = aggregateDomain(name);
         _sketches->_dns_topQname2.update(std::string(aggDomain.first));
         if (aggDomain.second.size()) {
-            _sketches->_dns_topQname3.update(std::string(aggDomain.second));
+            std::string s(aggDomain.second);
+            _sketches->_dns_topQname3.update(s);
         }
     }
 }

tests/test_metrics.cpp

@@ -0,0 +1,27 @@
+#include <DnsLayer.h>
+#include <ProtocolType.h>
+#include <catch2/catch.hpp>
+#include <sstream>
+
+#include "metrics.h"
+
+TEST_CASE("metrics", "[metrics]")
+{
+
+    SECTION("random qnames")
+    {
+        pktvisor::MetricsMgr mm(false, 5, 100);
+        mm.setInitialShiftTS();
+
+        for (int i = 0; i < 9; i++) {
+            for (int k = 0; k < 11; k++) {
+                pcpp::DnsLayer dns;
+                dns.getDnsHeader()->queryOrResponse = pktvisor::query;
+                std::stringstream name;
+                name << "0000" << k << ".0000" << i << ".com";
+                dns.addQuery(name.str(), pcpp::DnsType::DNS_TYPE_A, pcpp::DnsClass::DNS_CLASS_IN);
+                mm.newDNSPacket(&dns, pktvisor::Direction::toHost, pcpp::IPv4, pcpp::UDP);
+            }
+        }
+    }
+}