fix benchmark report

Author: ndyakov

hset_benchmark_test.go

@@ -101,7 +101,11 @@ func benchmarkHSETOperations(b *testing.B, rdb *redis.Client, ctx context.Contex
 	avgTimePerOp := b.Elapsed().Nanoseconds() / int64(operations*b.N)
 	b.ReportMetric(float64(avgTimePerOp), "ns/op")
 	// report average time in milliseconds from totalTimes
-	avgTimePerOpMs := totalTimes[0].Milliseconds() / int64(len(totalTimes))
+	sumTime := time.Duration(0)
+	for _, t := range totalTimes {
+		sumTime += t
+	}
+	avgTimePerOpMs := sumTime.Milliseconds() / int64(len(totalTimes))
 	b.ReportMetric(float64(avgTimePerOpMs), "ms")
 }
 
@@ -156,7 +160,12 @@ func benchmarkHSETOperationsConcurrent(b *testing.B, rdb *redis.Client, ctx cont
 	avgTimePerOp := b.Elapsed().Nanoseconds() / int64(operations*b.N)
 	b.ReportMetric(float64(avgTimePerOp), "ns/op")
 	// report average time in milliseconds from totalTimes
-	avgTimePerOpMs := totalTimes[0].Milliseconds() / int64(len(totalTimes))
+
+	sumTime := time.Duration(0)
+	for _, t := range totalTimes {
+		sumTime += t
+	}
+	avgTimePerOpMs := sumTime.Milliseconds() / int64(len(totalTimes))
 	b.ReportMetric(float64(avgTimePerOpMs), "ms")
 }
 
@@ -263,7 +272,11 @@ func benchmarkHSETPipelined(b *testing.B, rdb *redis.Client, ctx context.Context
 	avgTimePerOp := b.Elapsed().Nanoseconds() / int64(operations*b.N)
 	b.ReportMetric(float64(avgTimePerOp), "ns/op")
 	// report average time in milliseconds from totalTimes
-	avgTimePerOpMs := totalTimes[0].Milliseconds() / int64(len(totalTimes))
+	sumTime := time.Duration(0)
+	for _, t := range totalTimes {
+		sumTime += t
+	}
+	avgTimePerOpMs := sumTime.Milliseconds() / int64(len(totalTimes))
 	b.ReportMetric(float64(avgTimePerOpMs), "ms")
 }