lib/ddmetrics/stopwatch.rb in ddmetrics-1.0.1 vs lib/ddmetrics/stopwatch.rb in ddmetrics-1.1.0

@@ -1,9 +1,11 @@
 # frozen_string_literal: true
 
 module DDMetrics
   class Stopwatch
+    NANOS_PER_SECOND = 1_000_000_000
+
     class AlreadyRunningError < StandardError
       def message
         'Cannot start, because stopwatch is already running'
       end
     end
@@ -19,34 +21,50 @@
         'Cannot get duration, because stopwatch is still running'
       end
     end
 
     def initialize
-      @duration = 0.0
+      @duration = 0
       @last_start = nil
     end
 
+    def run
+      start
+      yield
+    ensure
+      stop
+    end
+
     def start
       raise AlreadyRunningError if running?
-      @last_start = Time.now
+
+      @last_start = nanos_now
     end
 
     def stop
       raise NotRunningError unless running?
-      @duration += (Time.now - @last_start)
+
+      @duration += (nanos_now - @last_start)
       @last_start = nil
     end
 
     def duration
       raise StillRunningError if running?
-      @duration
+
+      @duration.to_f / NANOS_PER_SECOND
     end
 
     def running?
       !@last_start.nil?
     end
 
     def stopped?
       !running?
+    end
+
+    private
+
+    def nanos_now
+      Process.clock_gettime(Process::CLOCK_MONOTONIC, :nanosecond)
     end
   end
 end