Merge pull request #400 from PEZ/crystal-ns-measure

In-process runner: Crystal: Use nanoseconds for the measurements

Author: PEZ

Diff for: lib/crystal/benchmark.cr

@@ -11,15 +11,16 @@ module Enumerable
 end
 
 def bench(run_ms : Int32, &fn)
-	times = Array(Int32).new
+	times = Array(Int64).new
 	result = 0
 	secs = 0
-	
-	while(times.sum < run_ms && !(times.sum == 0 && times.size > 0))
+	run_ns = run_ms * 1_000_000.0
+
+	while(times.sum < run_ns && !(times.sum == 0 && times.size > 0))
 		a = Time.measure {result = yield}
-		times << a.milliseconds
+		times << a.nanoseconds
 
-		if (times.sum / 1000).round > secs
+		if (times.sum / 1_000_000_000).round > secs
 			STDERR.print '.'
 			secs += 1
 		end
@@ -33,8 +34,8 @@ def format_bench(data, &formatter)
 	raise "no data!" if data[:times].empty?
 
 	result = yield data[:result]
-	times = data[:times]
+	times = data[:times].map &./(1_000_000)
 
 	# mean_ms,std-dev-ms,min_ms,max_ms,times,result
-	return "#{times.sum/times.size},#{times.std_dev},#{times.min},#{times.max},#{times.size},#{result}"
+	"#{times.sum/times.size},#{times.std_dev},#{times.min},#{times.max},#{times.size},#{result}"
 end