benchmark_copyby_test.go

package copyby_test

/*
$ go test -bench=. -benchmem                                                                                                                                                                                        ∞
goos: darwin
goarch: amd64
pkg: github.com/jnericks/copyby
BenchmarkCopyByStruct-12                1000000000               0.257 ns/op           0 B/op          0 allocs/op
BenchmarkCopyByStructNoInline-12        525012592                2.26 ns/op            0 B/op          0 allocs/op
BenchmarkCopyByPtr-12                   1000000000               0.262 ns/op           0 B/op          0 allocs/op
BenchmarkCopyByPtrNoInline-12           700563824                1.72 ns/op            0 B/op          0 allocs/op
PASS
ok      github.com/jnericks/copyby      3.720s
*/

import "testing"

var s = S{
	Number: 99,
	Text:   "Ninety-Nine",
}

func BenchmarkCopyByStruct(b *testing.B) {
	var d D
	for i := 0; i < b.N; i++ {
		d = byStruct(s)
	}
	if s.Number != d.Number {
		b.Fail()
	}
}

func BenchmarkCopyByStructNoInline(b *testing.B) {
	var d D
	for i := 0; i < b.N; i++ {
		d = byStructNoInline(s)
	}
	if s.Number != d.Number {
		b.Fail()
	}
}

func BenchmarkCopyByPtr(b *testing.B) {
	var d D
	for i := 0; i < b.N; i++ {
		d = byPtr(&s)
	}
	if s.Number != d.Number {
		b.Fail()
	}
}

func BenchmarkCopyByPtrNoInline(b *testing.B) {
	var d D
	for i := 0; i < b.N; i++ {
		d = byPtrNoInline(&s)
	}
	if s.Number != d.Number {
		b.Fail()
	}
}

type S struct {
	Number int
	Text   string
}

type D struct {
	Text   string
	Number int
}

func byStruct(v S) D {
	return D{
		Number: v.Number,
		Text:   v.Text,
	}
}

//go:noinline
func byStructNoInline(v S) D {
	return D{
		Number: v.Number,
		Text:   v.Text,
	}
}

func byPtr(v *S) D {
	return D{
		Number: v.Number,
		Text:   v.Text,
	}
}

//go:noinline
func byPtrNoInline(v *S) D {
	return D{
		Number: v.Number,
		Text:   v.Text,
	}
}