restic/internal/restic/duration.go

139 lines
2.2 KiB
Go

package restic
import (
"fmt"
"strconv"
"strings"
"unicode"
"github.com/restic/restic/internal/errors"
)
// Duration is similar to time.Duration, except it only supports larger ranges
// like hours, days, months, and years.
type Duration struct {
Hours, Days, Months, Years int
}
func (d Duration) String() string {
var s string
if d.Years != 0 {
s += fmt.Sprintf("%dy", d.Years)
}
if d.Months != 0 {
s += fmt.Sprintf("%dm", d.Months)
}
if d.Days != 0 {
s += fmt.Sprintf("%dd", d.Days)
}
if d.Hours != 0 {
s += fmt.Sprintf("%dh", d.Hours)
}
return s
}
func nextNumber(input string) (num int, rest string, err error) {
if len(input) == 0 {
return 0, "", nil
}
var (
n string
negative bool
)
if input[0] == '-' {
negative = true
input = input[1:]
}
for i, s := range input {
if !unicode.IsNumber(s) {
rest = input[i:]
break
}
n += string(s)
}
if len(n) == 0 {
return 0, input, errors.New("no number found")
}
num, err = strconv.Atoi(n)
if err != nil {
panic(err)
}
if negative {
num = -num
}
return num, rest, nil
}
// ParseDuration parses a duration from a string. The format is `6y5m234d37h`
func ParseDuration(s string) (Duration, error) {
var (
d Duration
num int
err error
)
s = strings.TrimSpace(s)
for s != "" {
num, s, err = nextNumber(s)
if err != nil {
return Duration{}, err
}
if len(s) == 0 {
return Duration{}, errors.Errorf("no unit found after number %d", num)
}
switch s[0] {
case 'y':
d.Years = num
case 'm':
d.Months = num
case 'd':
d.Days = num
case 'h':
d.Hours = num
default:
return Duration{}, errors.Errorf("invalid unit %q found after number %d", s[0], num)
}
s = s[1:]
}
return d, nil
}
// Set calls ParseDuration and updates d.
func (d *Duration) Set(s string) error {
v, err := ParseDuration(s)
if err != nil {
return err
}
*d = v
return nil
}
// Type returns the type of Duration, usable within github.com/spf13/pflag and
// in help texts.
func (d Duration) Type() string {
return "duration"
}
// Zero returns true if the duration is empty (all values are set to zero).
func (d Duration) Zero() bool {
return d.Years == 0 && d.Months == 0 && d.Days == 0 && d.Hours == 0
}