Go method indirection benchmarks

indirection_test.go

package fs

// indirection techniques in go
//BenchmarkDirectFib-12	2000000000	         0.13 ns/op
//BenchmarkSavePtr-12  	      30	  34612496 ns/op
//BenchmarkUseBool-12  	1000000000	         0.53 ns/op
//BenchmarkIface-12    	2000000000	         0.16 ns/op
//ok  	fs	27.053s

import "testing"

type v struct {
}

func (x *v) fib(n int) int {
	if n < 2 {
		return n
	}
	return x.fib(n-1) + x.fib(n-2)
}
func BenchmarkDirectFib(b *testing.B) {
	x := v{}
	x.fib(38)
}

type q struct {
	f func(n int) int
}

func (x *q) runfib(n int) int {
	return x.f(n)
}
func (x *q) fib2(n int) int {
	if n < 2 {
		return n
	}
	return x.runfib(n-1) + x.runfib(n-2)
}
func BenchmarkSavePtr(b *testing.B) {
	x := q{}
	x.f = x.fib2
	x.runfib(38)
}

type bb struct {
	use bool
}

func (x *bb) runfib(n int) int {
	if x.use {
		return x.fib2(n)
	} else {
		return 5 * 4
	}
}
func (x *bb) fib2(n int) int {
	if n < 2 {
		return n
	}
	return x.runfib(n-1) + x.runfib(n-2)
}
func BenchmarkUseBool(b *testing.B) {
	x := bb{}
	x.use = true
	x.runfib(38)
}

type iimpl struct{}

func (x *iimpl) fib(iface i, n int) int {
	if n < 2 {
		return n
	}
	return iface.fib(iface, n-1) + iface.fib(iface, n-2)
}

type i interface {
	fib(iface i, n int) int
}

func BenchmarkIface(b *testing.B) {
	x := iimpl{}
	x.fib(&x, 38)
}