ip_bench.txt

$ go test -bench=.
goos: darwin
goarch: amd64
pkg: github.com/svolobuev/fox/ip
BenchmarkToUint32-4   	10000000	       118 ns/op	      16 B/op	       1 allocs/op
BenchmarkToString-4   	20000000	        56.7 ns/op	      16 B/op	       1 allocs/op
PASS
ok  	github.com/svolobuev/fox/ip	2.519s

ip_ip.go

package ip

import (
	"encoding/binary"
	"errors"
	"net"
)

func ToUint32(input string) (uint32, error) {
	ip := net.ParseIP(input)
	if ip == nil {
		return 0, errors.New("wrong input format, input like as ip: 127.0.01, 10.10.242.125")
	}
	ip = ip.To4()

	return binary.BigEndian.Uint32(ip), nil
}

func ToString(input uint32) string {
	ipByte := make([]byte, 4)
	binary.BigEndian.PutUint32(ipByte, input)

	return net.IP(ipByte).String()
}

ip_ip_test.go

package ip

import (
	"testing"
)

const ipAsString = "127.0.0.1"
const ipAsLong = 2130706433

func TestToUint32(t *testing.T) {
	ip, err := ToUint32(ipAsString)
	if err != nil {
		t.Error("Ip2Long error", err)
	}

	if ipAsLong != ip {
		t.Errorf("Expected: %d from %s, but given %d", ipAsLong, ipAsString, ip)
	}
}

func TestToString(t *testing.T) {
	ip := ToString(ipAsLong)

	if ipAsString != ip {
		t.Errorf("Expected: %s from %d, but given %s", ipAsString, ipAsLong, ip)
	}
}

func BenchmarkToUint32(b *testing.B) {
	b.ReportAllocs()

	for i := 0; i < b.N; i++ {
		_, _ = ToUint32(ipAsString)
	}
}

func BenchmarkToString(b *testing.B) {
	b.ReportAllocs()

	for i := 0; i < b.N; i++ {
		_ = ToString(ipAsLong)
	}
}