SeqManager.cpp: fix num discontinued bug and increase performance

worker/src/RTC/SeqManager.cpp

@@ -1,6 +1,7 @@
 #define MS_CLASS "RTC::SeqManager"
 // #define MS_LOG_DEV_LEVEL 3
 
+#include <iterator>
 #include "RTC/SeqManager.hpp"
 #include "Logger.hpp"
 
@@ -94,8 +95,8 @@ namespace RTC
 			}
 
 			// Count dropped entries before 'input' in order to adapt the base.
-			size_t dropped = std::count_if(
-			  this->dropped.begin(), this->dropped.end(), [&input](T i) { return i < input; });
+			size_t dropped = this->dropped.size()
+			 - std::distance(this->dropped.upper_bound(input) , this->dropped.end());
 
 			base -= dropped;
 		}

worker/test/src/RTC/TestSeqManager.cpp

@@ -402,4 +402,26 @@ SCENARIO("SeqManager", "[rtc]")
 		SeqManager<uint16_t> seqManager;
 		validate(seqManager, inputs);
 	}
+
+	SECTION("sync and drop some input near max-value")
+	{
+		// clang-format off
+		std::vector<TestSeqManagerInput<uint16_t>> inputs =
+		{
+			{ 65530,  1,  true, false },
+			{ 65531,  2, false, false },
+			{ 65532,  3, false, false },
+			{ 65533,  0, false, true  },
+			{ 65534,  0, false, true  },
+			{ 65535,  4, false, false },
+			{     0,  5, false, false },
+			{     1,  6, false, false },
+			{     2,  7, false, false },
+			{     3,  8, false, false }	
+		};
+		// clang-format on
+
+		SeqManager<uint16_t> seqManager;
+		validate(seqManager, inputs);
+	}
 }