vikunja-api/vendor/github.com/labstack/gommon/bytes/bytes.go
2018-06-10 11:11:42 +02:00

106 lines
1.8 KiB
Go

package bytes
import (
"fmt"
"regexp"
"strconv"
)
type (
Bytes struct {
}
)
const (
B = 1 << (10 * iota)
KB
MB
GB
TB
PB
EB
)
var (
pattern = regexp.MustCompile(`(?i)^(-?\d+)([KMGTP]B?|B)$`)
global = New()
)
// New creates a Bytes instance.
func New() *Bytes {
return &Bytes{}
}
// Format formats bytes integer to human readable string.
// For example, 31323 bytes will return 30.59KB.
func (*Bytes) Format(b int64) string {
multiple := ""
value := float64(b)
switch {
case b < KB:
return strconv.FormatInt(b, 10) + "B"
case b < MB:
value /= KB
multiple = "KB"
case b < MB:
value /= KB
multiple = "KB"
case b < GB:
value /= MB
multiple = "MB"
case b < TB:
value /= GB
multiple = "GB"
case b < PB:
value /= TB
multiple = "TB"
case b < EB:
value /= PB
multiple = "PB"
}
return fmt.Sprintf("%.02f%s", value, multiple)
}
// Parse parses human readable bytes string to bytes integer.
// For example, 6GB (6G is also valid) will return 6442450944.
func (*Bytes) Parse(value string) (i int64, err error) {
parts := pattern.FindStringSubmatch(value)
if len(parts) < 3 {
return 0, fmt.Errorf("error parsing value=%s", value)
}
bytesString := parts[1]
multiple := parts[2]
bytes, err := strconv.ParseInt(bytesString, 10, 64)
if err != nil {
return
}
switch multiple {
case "B":
return bytes * B, nil
case "K", "KB":
return bytes * KB, nil
case "M", "MB":
return bytes * MB, nil
case "G", "GB":
return bytes * GB, nil
case "T", "TB":
return bytes * TB, nil
case "P", "PB":
return bytes * PB, nil
}
return
}
// Format wraps global Bytes's Format function.
func Format(b int64) string {
return global.Format(b)
}
// Parse wraps global Bytes's Parse function.
func Parse(val string) (int64, error) {
return global.Parse(val)
}