benchmark clear feature in go1.21

clear_test.go

package main

import (
	"testing"
	"time"
)

func BenchmarkClearMapWithDelete(b *testing.B) {
	b.ReportAllocs()
	test := createMap(100000)

	for i := 0; i < b.N; i++ {
		for k := range test {
			delete(test, k)
		}
	}

}

func BenchmarkClearMapWithClear(b *testing.B) {
	b.ReportAllocs()
	test := createMap(100000)

	for i := 0; i < b.N; i++ {
		clear(test)
	}
}

func BenchmarkClearSliceWithoutClear(b *testing.B) {
	b.ReportAllocs()
	test := createSlice(100000)

	for i := 0; i < b.N; i++ {
		for k := range test {
			deleteSliceElement(test, k)
		}
	}
}

func BenchmarkClearSliceWithClear(b *testing.B) {
	b.ReportAllocs()
	test := createSlice(100000)

	for i := 0; i < b.N; i++ {
		clear(test)
	}
}

//go:noinline
func deleteSliceElement(slice []int64, element int) []int64 {
	slice[element] = slice[len(slice)-1]
	slice = slice[:len(slice)-1]
	return slice
}

func createMap(n int) map[int]int64 {
	data := make(map[int]int64)

	for i := 0; i < n; i++ {
		data[i] = time.Now().Unix()
	}

	return data
}

//go:noinline
func createSlice(n int) []int64 {
	data := make([]int64, 0)

	for i := 0; i < n; i++ {
		data = append(data, time.Now().Unix())
	}

	return data
}

Result:

goos: linux
goarch: amd64
cpu: AMD Ryzen 3 PRO 2300U w/ Radeon Vega Mobile Gfx
BenchmarkClearMapWithDelete
BenchmarkClearMapWithDelete-4       	415942981	         2.488 ns/op	       0 B/op	       0 allocs/op
BenchmarkClearMapWithClear
BenchmarkClearMapWithClear-4        	385395132	         2.602 ns/op	       0 B/op	       0 allocs/op
BenchmarkClearSliceWithoutClear
BenchmarkClearSliceWithoutClear-4   	    4663	    281625 ns/op	     879 B/op	       0 allocs/op
BenchmarkClearSliceWithClear
BenchmarkClearSliceWithClear-4      	   76146	     16391 ns/op	      53 B/op	       0 allocs/op
PASS