rclone/fs/sizesuffix.go
2018-10-11 14:47:58 +01:00

145 lines
2.9 KiB
Go

package fs
// SizeSuffix is parsed by flag with k/M/G suffixes
import (
"fmt"
"math"
"sort"
"strconv"
"strings"
"github.com/pkg/errors"
)
// SizeSuffix is an int64 with a friendly way of printing setting
type SizeSuffix int64
// Common multipliers for SizeSuffix
const (
Byte SizeSuffix = 1 << (iota * 10)
KibiByte
MebiByte
GibiByte
TebiByte
PebiByte
ExbiByte
)
// Turn SizeSuffix into a string and a suffix
func (x SizeSuffix) string() (string, string) {
scaled := float64(0)
suffix := ""
switch {
case x < 0:
return "off", ""
case x == 0:
return "0", ""
case x < 1<<10:
scaled = float64(x)
suffix = ""
case x < 1<<20:
scaled = float64(x) / (1 << 10)
suffix = "k"
case x < 1<<30:
scaled = float64(x) / (1 << 20)
suffix = "M"
case x < 1<<40:
scaled = float64(x) / (1 << 30)
suffix = "G"
case x < 1<<50:
scaled = float64(x) / (1 << 40)
suffix = "T"
default:
scaled = float64(x) / (1 << 50)
suffix = "P"
}
if math.Floor(scaled) == scaled {
return fmt.Sprintf("%.0f", scaled), suffix
}
return fmt.Sprintf("%.3f", scaled), suffix
}
// String turns SizeSuffix into a string
func (x SizeSuffix) String() string {
val, suffix := x.string()
return val + suffix
}
// Unit turns SizeSuffix into a string with a unit
func (x SizeSuffix) Unit(unit string) string {
val, suffix := x.string()
if val == "off" {
return val
}
return val + " " + suffix + unit
}
// Set a SizeSuffix
func (x *SizeSuffix) Set(s string) error {
if len(s) == 0 {
return errors.New("empty string")
}
if strings.ToLower(s) == "off" {
*x = -1
return nil
}
suffix := s[len(s)-1]
suffixLen := 1
var multiplier float64
switch suffix {
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.':
suffixLen = 0
multiplier = 1 << 10
case 'b', 'B':
multiplier = 1
case 'k', 'K':
multiplier = 1 << 10
case 'm', 'M':
multiplier = 1 << 20
case 'g', 'G':
multiplier = 1 << 30
case 't', 'T':
multiplier = 1 << 40
case 'p', 'P':
multiplier = 1 << 50
default:
return errors.Errorf("bad suffix %q", suffix)
}
s = s[:len(s)-suffixLen]
value, err := strconv.ParseFloat(s, 64)
if err != nil {
return err
}
if value < 0 {
return errors.Errorf("size can't be negative %q", s)
}
value *= multiplier
*x = SizeSuffix(value)
return nil
}
// Type of the value
func (x *SizeSuffix) Type() string {
return "int64"
}
// Scan implements the fmt.Scanner interface
func (x *SizeSuffix) Scan(s fmt.ScanState, ch rune) error {
token, err := s.Token(true, nil)
if err != nil {
return err
}
return x.Set(string(token))
}
// SizeSuffixList is a sclice SizeSuffix values
type SizeSuffixList []SizeSuffix
func (l SizeSuffixList) Len() int { return len(l) }
func (l SizeSuffixList) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
func (l SizeSuffixList) Less(i, j int) bool { return l[i] < l[j] }
// Sort sorts the list
func (l SizeSuffixList) Sort() {
sort.Sort(l)
}