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v2fly/common/units/bytesize.go
2021-11-27 14:32:07 +08:00

101 lines
1.8 KiB
Go

package units
import (
"errors"
"strconv"
"strings"
"unicode"
)
var (
errInvalidSize = errors.New("invalid size")
errInvalidUnit = errors.New("invalid or unsupported unit")
)
// ByteSize is the size of bytes
type ByteSize uint64
const (
_ = iota
// KB = 1KB
KB ByteSize = 1 << (10 * iota)
// MB = 1MB
MB
// GB = 1GB
GB
// TB = 1TB
TB
// PB = 1PB
PB
// EB = 1EB
EB
)
func (b ByteSize) String() string {
unit := ""
value := float64(0)
switch {
case b == 0:
return "0"
case b < KB:
unit = "B"
value = float64(b)
case b < MB:
unit = "KB"
value = float64(b) / float64(KB)
case b < GB:
unit = "MB"
value = float64(b) / float64(MB)
case b < TB:
unit = "GB"
value = float64(b) / float64(GB)
case b < PB:
unit = "TB"
value = float64(b) / float64(TB)
case b < EB:
unit = "PB"
value = float64(b) / float64(PB)
default:
unit = "EB"
value = float64(b) / float64(EB)
}
result := strconv.FormatFloat(value, 'f', 2, 64)
result = strings.TrimSuffix(result, ".0")
return result + unit
}
// Parse parses ByteSize from string
func (b *ByteSize) Parse(s string) error {
s = strings.TrimSpace(s)
s = strings.ToUpper(s)
i := strings.IndexFunc(s, unicode.IsLetter)
if i == -1 {
return errInvalidUnit
}
bytesString, multiple := s[:i], s[i:]
bytes, err := strconv.ParseFloat(bytesString, 64)
if err != nil || bytes <= 0 {
return errInvalidSize
}
switch multiple {
case "B":
*b = ByteSize(bytes)
case "K", "KB", "KIB":
*b = ByteSize(bytes * float64(KB))
case "M", "MB", "MIB":
*b = ByteSize(bytes * float64(MB))
case "G", "GB", "GIB":
*b = ByteSize(bytes * float64(GB))
case "T", "TB", "TIB":
*b = ByteSize(bytes * float64(TB))
case "P", "PB", "PIB":
*b = ByteSize(bytes * float64(PB))
case "E", "EB", "EIB":
*b = ByteSize(bytes * float64(EB))
default:
return errInvalidUnit
}
return nil
}