Initial import

Makefile

@@ -0,0 +1,2 @@
+all:
+	go test -v -bench .

README.md

@@ -0,0 +1,24 @@
+# Introduction
+
+Naive performance test of doing type assertion using:
+
+ * The native way
+
+or...
+
+ * Using reflection to avoid code repetition
+
+# Results
+
+```
+BenchmarkAppendNativeTypeAssertion       5000000           666 ns/op
+BenchmarkAppendReflectionTypeAssertion   5000000           529 ns/op
+```
+
+# Thanks to
+
+ * Dan Kortschak <[email protected]>
+ * Dmitry Vyukov <[email protected]>
+ * Xingtao Zhao  <[email protected]>
+ * Egon          <[email protected]>
+ * Chris Dollin  <[email protected]>

bench_test.go

@@ -0,0 +1,21 @@
+package bench
+
+import "testing"
+
+func BenchmarkAppendNativeTypeAssertion(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		col := &FloatCol{}
+		col.AppendNativeTypeAssertion(1.2)
+		col.AppendNativeTypeAssertion("4.3")
+		col.AppendNativeTypeAssertion(float32(123))
+	}
+}
+
+func BenchmarkAppendReflectionTypeAssertion(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		col := &FloatCol{}
+		col.AppendReflectionTypeAssertion(1.2)
+		col.AppendReflectionTypeAssertion("4.3")
+		col.AppendReflectionTypeAssertion(float32(123))
+	}
+}

floatcol.go

@@ -0,0 +1,5 @@
+package bench
+
+type FloatCol struct {
+	rows []float64
+}

native.go

@@ -0,0 +1,42 @@
+package bench
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func (c *FloatCol) AppendNativeTypeAssertion(row interface{}) error {
+	switch value := row.(type) {
+	case float32:
+		c.rows = append(c.rows, float64(value))
+	case float64:
+		c.rows = append(c.rows, float64(value))
+	case int:
+		c.rows = append(c.rows, float64(value))
+	case int8:
+		c.rows = append(c.rows, float64(value))
+	case int16:
+		c.rows = append(c.rows, float64(value))
+	case int32:
+		c.rows = append(c.rows, float64(value))
+	case int64:
+		c.rows = append(c.rows, float64(value))
+	case uint:
+		c.rows = append(c.rows, float64(value))
+	case uint8:
+		c.rows = append(c.rows, float64(value))
+	case uint16:
+		c.rows = append(c.rows, float64(value))
+	case uint32:
+		c.rows = append(c.rows, float64(value))
+	case uint64:
+		c.rows = append(c.rows, float64(value))
+	default:
+		num, err := strconv.ParseFloat(fmt.Sprint(row), 64)
+		if err != nil {
+			return err
+		}
+		c.rows = append(c.rows, num)
+	}
+	return nil
+}

reflection.go

@@ -0,0 +1,25 @@
+package bench
+
+import (
+	"reflect"
+	"strconv"
+)
+
+func (c *FloatCol) AppendReflectionTypeAssertion(row interface{}) error {
+	rv := reflect.ValueOf(row)
+	switch rv.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
+		reflect.Uintptr:
+		c.rows = append(c.rows, float64(rv.Int()))
+	case reflect.Float32, reflect.Float64:
+		c.rows = append(c.rows, rv.Float())
+	default:
+		num, err := strconv.ParseFloat(rv.String(), 64)
+		if err != nil {
+			return err
+		}
+		c.rows = append(c.rows, num)
+	}
+	return nil
+}