status-go/vendor/github.com/dustin/go-humanize/bytes.go

144 lines
2.5 KiB
Go

package humanize
import (
"fmt"
"math"
"strconv"
"strings"
"unicode"
)
// IEC Sizes.
// kibis of bits
const (
Byte = 1 << (iota * 10)
KiByte
MiByte
GiByte
TiByte
PiByte
EiByte
)
// SI Sizes.
const (
IByte = 1
KByte = IByte * 1000
MByte = KByte * 1000
GByte = MByte * 1000
TByte = GByte * 1000
PByte = TByte * 1000
EByte = PByte * 1000
)
var bytesSizeTable = map[string]uint64{
"b": Byte,
"kib": KiByte,
"kb": KByte,
"mib": MiByte,
"mb": MByte,
"gib": GiByte,
"gb": GByte,
"tib": TiByte,
"tb": TByte,
"pib": PiByte,
"pb": PByte,
"eib": EiByte,
"eb": EByte,
// Without suffix
"": Byte,
"ki": KiByte,
"k": KByte,
"mi": MiByte,
"m": MByte,
"gi": GiByte,
"g": GByte,
"ti": TiByte,
"t": TByte,
"pi": PiByte,
"p": PByte,
"ei": EiByte,
"e": EByte,
}
func logn(n, b float64) float64 {
return math.Log(n) / math.Log(b)
}
func humanateBytes(s uint64, base float64, sizes []string) string {
if s < 10 {
return fmt.Sprintf("%d B", s)
}
e := math.Floor(logn(float64(s), base))
suffix := sizes[int(e)]
val := math.Floor(float64(s)/math.Pow(base, e)*10+0.5) / 10
f := "%.0f %s"
if val < 10 {
f = "%.1f %s"
}
return fmt.Sprintf(f, val, suffix)
}
// Bytes produces a human readable representation of an SI size.
//
// See also: ParseBytes.
//
// Bytes(82854982) -> 83 MB
func Bytes(s uint64) string {
sizes := []string{"B", "kB", "MB", "GB", "TB", "PB", "EB"}
return humanateBytes(s, 1000, sizes)
}
// IBytes produces a human readable representation of an IEC size.
//
// See also: ParseBytes.
//
// IBytes(82854982) -> 79 MiB
func IBytes(s uint64) string {
sizes := []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"}
return humanateBytes(s, 1024, sizes)
}
// ParseBytes parses a string representation of bytes into the number
// of bytes it represents.
//
// See Also: Bytes, IBytes.
//
// ParseBytes("42 MB") -> 42000000, nil
// ParseBytes("42 mib") -> 44040192, nil
func ParseBytes(s string) (uint64, error) {
lastDigit := 0
hasComma := false
for _, r := range s {
if !(unicode.IsDigit(r) || r == '.' || r == ',') {
break
}
if r == ',' {
hasComma = true
}
lastDigit++
}
num := s[:lastDigit]
if hasComma {
num = strings.Replace(num, ",", "", -1)
}
f, err := strconv.ParseFloat(num, 64)
if err != nil {
return 0, err
}
extra := strings.ToLower(strings.TrimSpace(s[lastDigit:]))
if m, ok := bytesSizeTable[extra]; ok {
f *= float64(m)
if f >= math.MaxUint64 {
return 0, fmt.Errorf("too large: %v", s)
}
return uint64(f), nil
}
return 0, fmt.Errorf("unhandled size name: %v", extra)
}