#golang

parge_data_storage_unit.go

var dataUnitPattern, _ = regexp.Compile(`(\d+)\s*([a-zA-Z]+)`)

func ParseDataStorage(s string) (int64, error) {
	all := dataUnitPattern.FindAllStringSubmatch(s, -1)
	if len(all) != 1 || len(all[0]) != 3 {
		return 0, fmt.Errorf("invalid %s", s)
	}
	d, u := all[0][1], all[0][2]
	num, err := strconv.ParseInt(d, 10, 32)
	if err != nil {
		return 0, errors.Wrapf(err, "invalid %s", s)
	}

	switch strings.ToUpper(u) {
	case "BYTES":
		return num * 1, nil
	case "KB":
		return num * 1024, nil
	case "MB":
		return num * 1024 * 1024, nil
	case "GB":
		return num * 1024 * 1024 * 1024, nil
	case "TB":
		return num * 1024 * 1024 * 1024 * 1024, nil
	default:
		return 0, fmt.Errorf("unknown unit %s", u)
	}
}

func TestParseDataUnit(t *testing.T) {
	data, err := ParseDataStorage("100MB")
	assert.Equal(t, err, nil)
	assert.Equal(t, data, int64(100*1024*1024))

	data, err = ParseDataStorage("100mB")
	assert.Equal(t, err, nil)
	assert.Equal(t, data, int64(100*1024*1024))

	data, err = ParseDataStorage("100Mb")
	assert.Equal(t, data, int64(100*1024*1024))
	assert.Equal(t, err, nil)

	data, err = ParseDataStorage("100 MB")
	assert.Equal(t, err, nil)
	assert.Equal(t, data, int64(100*1024*1024))

	data, err = ParseDataStorage("100 mB")
	assert.Equal(t, err, nil)
	assert.Equal(t, data, int64(100*1024*1024))

	data, err = ParseDataStorage("100 Mb")
	assert.Equal(t, err, nil)
	assert.Equal(t, data, int64(100*1024*1024))

	data, err = ParseDataStorage("Mb")
	assert.NotEqual(t, err, nil)

	data, err = ParseDataStorage("")
	assert.NotEqual(t, err, nil)

	data, err = ParseDataStorage("100")
	assert.NotEqual(t, err, nil)
}