pkg/units: Refactor regexp.Compile to init()

No need to recompile a fixed regular expression each time the function
executes. Abstracting it to the `init()` method.

Docker-DCO-1.1-Signed-off-by: Francisco Carriedo <fcarriedo@gmail.com> (github: fcarriedo)
This commit is contained in:
Francisco Carriedo 2014-07-21 23:50:27 -07:00
parent 0fd37bd7ac
commit a4d57d8a85

View file

@ -7,6 +7,15 @@ import (
"strings"
)
var sizeRegex *regexp.Regexp
func init() {
var err error
if sizeRegex, err = regexp.Compile("^(\\d+)([kKmMgGtTpP])?[bB]?$"); err != nil {
panic("Failed to compile the 'size' regular expression")
}
}
// HumanSize returns a human-readable approximation of a size
// using SI standard (eg. "44kB", "17MB")
func HumanSize(size int64) string {
@ -24,12 +33,7 @@ func HumanSize(size int64) string {
// FromHumanSize returns an integer from a human-readable specification of a size
// using SI standard (eg. "44kB", "17MB")
func FromHumanSize(size string) (int64, error) {
re, err := regexp.Compile("^(\\d+)([kKmMgGtTpP])?[bB]?$")
if err != nil {
return -1, fmt.Errorf("%s does not specify not a size", size)
}
matches := re.FindStringSubmatch(size)
matches := sizeRegex.FindStringSubmatch(size)
if len(matches) != 3 {
return -1, fmt.Errorf("Invalid size: '%s'", size)
@ -63,12 +67,7 @@ func FromHumanSize(size string) (int64, error) {
// 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+)([kKmMgGtTpP])?[bB]?$")
if err != nil {
return -1, err
}
matches := re.FindStringSubmatch(size)
matches := sizeRegex.FindStringSubmatch(size)
if len(matches) != 3 {
return -1, fmt.Errorf("Invalid size: '%s'", size)