generate_key_bench_test.go

package main

import (
	"fmt"
	"math/rand"
	"strings"
	"testing"
	"time"
)

func BenchmarkGenerateKey(b *testing.B) {
	const str = "1234567890qwertyuiopasdfghjklzxcvbnm"
	rand.Seed(time.Now().Unix())
	pattern := make([]string, 100)
	for i := range pattern {
		end := rand.Intn(len(str) - 5)
		pattern[i] = str[:end]
	}
	b.Run("strings.join", func(b *testing.B) {
		for n := 0; n < b.N; n++ {
			for i := 0; i < len(pattern)-2; i++ {
				_ = strings.Join([]string{"",
					pattern[i],
					pattern[i+1],
					pattern[i+2],
				}, "/")
			}
		}
	})
	b.Run("string.Builder", func(b *testing.B) {
		for n := 0; n < b.N; n++ {
			for i := 0; i < len(pattern)-2; i++ {
				var buf strings.Builder
				buf.WriteString("/")
				buf.WriteString(pattern[i])
				buf.WriteString("/")
				buf.WriteString(pattern[i+1])
				buf.WriteString("/")
				buf.WriteString(pattern[i+2])
				_ = buf.String()
			}
		}
	})
	b.Run("string.Builder/grow", func(b *testing.B) {
		for n := 0; n < b.N; n++ {
			for i := 0; i < len(pattern)-2; i++ {
				var buf strings.Builder
				buf.Grow(len(pattern[i]) + len(pattern[i+1]) + len(pattern[i+2]) + 3)
				buf.WriteString("/")
				buf.WriteString(pattern[i])
				buf.WriteString("/")
				buf.WriteString(pattern[i+1])
				buf.WriteString("/")
				buf.WriteString(pattern[i+2])
				_ = buf.String()
			}
		}
	})
	b.Run("fmt.Sprintf", func(b *testing.B) {
		for n := 0; n < b.N; n++ {
			for i := 0; i < len(pattern)-2; i++ {
				_ = fmt.Sprintf("/%s/%s/%s", pattern[i], pattern[i+1], pattern[i+2])
			}
		}
	})
}

Running tool: /usr/local/go/bin/go test -benchmem -run=^$ -bench ^BenchmarkGenerateKey$ ./

goos: darwin
goarch: amd64
pkg: github.com/WinTicket/server/pkg/tracer
cpu: Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
BenchmarkGenerateKey/strings.join-16         	  161467	      7238 ns/op	    5472 B/op	      98 allocs/op
BenchmarkGenerateKey/string.Builder-16       	   91117	     12497 ns/op	   12120 B/op	     340 allocs/op
BenchmarkGenerateKey/string.Builder/grow-16  	  249152	      5373 ns/op	    5472 B/op	      98 allocs/op
BenchmarkGenerateKey/fmt.Sprintf-16          	   53454	     22245 ns/op	   10136 B/op	     389 allocs/op
PASS