go bcrypt benchmark

main_test.go

package main

import (
	"testing"

	"golang.org/x/crypto/bcrypt"
)

func BenchmarkBcrypt4(b *testing.B) {
	benchBcrypt(b, 4)
}
func BenchmarkBcrypt5(b *testing.B) {
	benchBcrypt(b, 5)
}
func BenchmarkBcrypt6(b *testing.B) {
	benchBcrypt(b, 6)
}
func BenchmarkBcrypt7(b *testing.B) {
	benchBcrypt(b, 7)
}
func BenchmarkBcrypt8(b *testing.B) {
	benchBcrypt(b, 8)
}
func BenchmarkBcrypt9(b *testing.B) {
	benchBcrypt(b, 9)
}
func BenchmarkBcrypt10(b *testing.B) {
	benchBcrypt(b, 10)
}

func benchBcrypt(b *testing.B, cost int) {
	b.StopTimer()
	pass, _ := bcrypt.GenerateFromPassword([]byte("foo bar"), cost)
	b.StartTimer()
	for i := 0; i < b.N; i++ {
		bcrypt.CompareHashAndPassword(pass, []byte("foo bar"))
	}
}

output

# go test -v -bench=.
testing: warning: no tests to run
PASS
BenchmarkBcrypt4	    1000	   1779279 ns/op
BenchmarkBcrypt5	     500	   3227878 ns/op
BenchmarkBcrypt6	     200	   6379871 ns/op
BenchmarkBcrypt7	     100	  12690109 ns/op
BenchmarkBcrypt8	      50	  25364979 ns/op
BenchmarkBcrypt9	      30	  50730959 ns/op
BenchmarkBcrypt10	      10	 100569334 ns/op
ok  	tmp/dme	12.430s