Optimize Record() to avoid extra allocations

stats/benchmark_test.go

@@ -109,5 +109,13 @@ func BenchmarkRecord8_8Tags(b *testing.B) {
 }
 
 func makeMeasure() *stats.Int64Measure {
-	return stats.Int64("m", "test measure", "")
+	m := stats.Int64("m", "test measure", "")
+	v := &view.View{
+		Measure:     m,
+		Aggregation: view.Sum(),
+	}
+	if err := view.Register(v); err != nil {
+		panic(err.Error())
+	}
+	return m
 }

stats/record.go

@@ -89,7 +89,24 @@ func createRecordOption(ros ...Options) *recordOptions {
 // Record records one or multiple measurements with the same context at once.
 // If there are any tags in the context, measurements will be tagged with them.
 func Record(ctx context.Context, ms ...Measurement) {
-	RecordWithOptions(ctx, WithMeasurements(ms...))
+	// Record behaves the same as RecordWithOptions, but because we do not have to handle generic functionality
+	// (RecordOptions) we can reduce some allocations to speed up this hot path
+	if len(ms) == 0 {
+		return
+	}
+	recorder := internal.DefaultRecorder
+	record := false
+	for _, m := range ms {
+		if m.desc.subscribed() {
+			record = true
+			break
+		}
+	}
+	if !record {
+		return
+	}
+	recorder(tag.FromContext(ctx), ms, nil)
+	return
 }
 
 // RecordWithTags records one or multiple measurements at once.