pkg/units/size.go
Otto Kekäläinen de0d8cfd0f Multiple fixes to 'docker stats' output:
* Add space between values in docker stats output for easier parsing

  Old output could not be parsed easily because there were columns
  that did not have any separator. Also values that are together
  without any space is difficult to read even for humans.

* Update unit.HumanSize comment to match what the does actually does

Signed-off-by: Otto Kekäläinen <otto@seravo.fi>
2015-07-30 10:14:57 +03:00

95 lines
2.4 KiB
Go

package units
import (
"fmt"
"regexp"
"strconv"
"strings"
)
// See: http://en.wikipedia.org/wiki/Binary_prefix
const (
// Decimal
KB = 1000
MB = 1000 * KB
GB = 1000 * MB
TB = 1000 * GB
PB = 1000 * TB
// Binary
KiB = 1024
MiB = 1024 * KiB
GiB = 1024 * MiB
TiB = 1024 * GiB
PiB = 1024 * TiB
)
type unitMap map[string]int64
var (
decimalMap = unitMap{"k": KB, "m": MB, "g": GB, "t": TB, "p": PB}
binaryMap = unitMap{"k": KiB, "m": MiB, "g": GiB, "t": TiB, "p": PiB}
sizeRegex = regexp.MustCompile(`^(\d+)([kKmMgGtTpP])?[bB]?$`)
)
var decimapAbbrs = []string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"}
var binaryAbbrs = []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"}
// CustomSize returns a human-readable approximation of a size
// using custom format.
func CustomSize(format string, size float64, base float64, _map []string) string {
i := 0
for size >= base {
size = size / base
i++
}
return fmt.Sprintf(format, size, _map[i])
}
// HumanSize returns a human-readable approximation of a size
// capped at 4 valid numbers (eg. "2.746 MB", "796 KB").
func HumanSize(size float64) string {
return CustomSize("%.4g %s", size, 1000.0, decimapAbbrs)
}
// BytesSize returns a human-readable size in bytes, kibibytes,
// mebibytes, gibibytes, or tebibytes (eg. "44kiB", "17MiB").
func BytesSize(size float64) string {
return CustomSize("%.4g %s", size, 1024.0, binaryAbbrs)
}
// FromHumanSize returns an integer from a human-readable specification of a
// size using SI standard (eg. "44kB", "17MB").
func FromHumanSize(size string) (int64, error) {
return parseSize(size, decimalMap)
}
// RAMInBytes parses a human-readable string representing an amount of RAM
// in bytes, kibibytes, mebibytes, gibibytes, or tebibytes and
// returns the number of bytes, or -1 if the string is unparseable.
// Units are case-insensitive, and the 'b' suffix is optional.
func RAMInBytes(size string) (int64, error) {
return parseSize(size, binaryMap)
}
// Parses the human-readable size string into the amount it represents.
func parseSize(sizeStr string, uMap unitMap) (int64, error) {
matches := sizeRegex.FindStringSubmatch(sizeStr)
if len(matches) != 3 {
return -1, fmt.Errorf("invalid size: '%s'", sizeStr)
}
size, err := strconv.ParseInt(matches[1], 10, 0)
if err != nil {
return -1, err
}
unitPrefix := strings.ToLower(matches[2])
if mul, ok := uMap[unitPrefix]; ok {
size *= mul
}
return size, nil
}