pkg/units/size.go
Francisco Carriedo 299020949f pkg/units: Using 'case' instead of trickled ifs
Seems the perfect case for 'case' ;).

Docker-DCO-1.1-Signed-off-by: Francisco Carriedo <fcarriedo@gmail.com> (github: fcarriedo)
2014-07-23 20:38:36 -07:00

96 lines
2.1 KiB
Go

package units
import (
"fmt"
"regexp"
"strconv"
"strings"
)
// HumanSize returns a human-readable approximation of a size
// using SI standard (eg. "44kB", "17MB")
func HumanSize(size int64) string {
i := 0
var sizef float64
sizef = float64(size)
units := []string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"}
for sizef >= 1000.0 {
sizef = sizef / 1000.0
i++
}
return fmt.Sprintf("%.4g %s", sizef, units[i])
}
// FromHumanSize returns an integer from a human-readable specification of a size
// using SI standard (eg. "44kB", "17MB")
func FromHumanSize(size string) (int64, error) {
re, err := regexp.Compile("^(\\d+)([kKmMgGtTpP])?[bB]?$")
if err != nil {
return -1, fmt.Errorf("%s does not specify not a size", size)
}
matches := re.FindStringSubmatch(size)
if len(matches) != 3 {
return -1, fmt.Errorf("Invalid size: '%s'", size)
}
theSize, err := strconv.ParseInt(matches[1], 10, 0)
if err != nil {
return -1, err
}
unit := strings.ToLower(matches[2])
switch unit {
case "k":
theSize *= 1000
case "m":
theSize *= 1000 * 1000
case "g":
theSize *= 1000 * 1000 * 1000
case "t":
theSize *= 1000 * 1000 * 1000 * 1000
case "p":
theSize *= 1000 * 1000 * 1000 * 1000 * 1000
}
return theSize, nil
}
// Parses a human-readable string representing an amount of RAM
// in bytes, kibibytes, mebibytes, gibibytes, or tebibytes and
// returns the number of bytes, or -1 if the string is unparseable.
// Units are case-insensitive, and the 'b' suffix is optional.
func RAMInBytes(size string) (int64, error) {
re, err := regexp.Compile("^(\\d+)([kKmMgGtT])?[bB]?$")
if err != nil {
return -1, err
}
matches := re.FindStringSubmatch(size)
if len(matches) != 3 {
return -1, fmt.Errorf("Invalid size: '%s'", size)
}
memLimit, err := strconv.ParseInt(matches[1], 10, 0)
if err != nil {
return -1, err
}
unit := strings.ToLower(matches[2])
switch unit {
case "k":
memLimit *= 1024
case "m":
memLimit *= 1024 * 1024
case "g":
memLimit *= 1024 * 1024 * 1024
case "t":
memLimit *= 1024 * 1024 * 1024 * 1024
}
return memLimit, nil
}