open-nomad/vendor/github.com/dustin/go-humanize/bytes.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

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)
}