add stopNs to timeutil::Timer

src/util/timeutil.cpp

@@ -5,6 +5,7 @@
 using std::chrono::duration_cast;
 using std::chrono::high_resolution_clock;
 using std::chrono::microseconds;
+using std::chrono::nanoseconds;
 
 timeutil::Timer::Timer() {
     start = high_resolution_clock::now();
@@ -14,6 +15,11 @@ int64_t timeutil::Timer::stop() {
         .count();
 }
 
+int64_t timeutil::Timer::stopNs() {
+    return duration_cast<nanoseconds>(high_resolution_clock::now() - start)
+        .count();
+}
+
 timeutil::ScopeLogTimer::ScopeLogTimer(long long id) : scopeid_(id) {
 }
 

src/util/timeutil.hpp

@@ -10,6 +10,7 @@ namespace timeutil {
     public:
         Timer();
         int64_t stop();
+        int64_t stopNs();
     };
 
     /**