35 lines
789 B
Go
35 lines
789 B
Go
|
package appservice
|
||
|
|
|
||
|
|
import (
|
||
|
|
"math/rand"
|
||
|
|
"time"
|
||
|
|
)
|
||
|
|
|
||
|
|
const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
|
||
|
|
const (
|
||
|
|
letterIdxBits = 6
|
||
|
|
letterIdxMask = 1<<letterIdxBits - 1
|
||
|
|
letterIdxMax = 63 / letterIdxBits
|
||
|
|
)
|
||
|
|
|
||
|
|
var src = rand.NewSource(time.Now().UnixNano())
|
||
|
|
|
||
|
|
// RandomString generates a random string of the given length.
|
||
|
|
func RandomString(n int) string {
|
||
|
|
b := make([]byte, n)
|
||
|
|
// A src.Int63() generates 63 random bits, enough for letterIdxMax characters!
|
||
|
|
for i, cache, remain := n-1, src.Int63(), letterIdxMax; i >= 0; {
|
||
|
|
if remain == 0 {
|
||
|
|
cache, remain = src.Int63(), letterIdxMax
|
||
|
|
}
|
||
|
|
if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
|
||
|
|
b[i] = letterBytes[idx]
|
||
|
|
i--
|
||
|
|
}
|
||
|
|
cache >>= letterIdxBits
|
||
|
|
remain--
|
||
|
|
}
|
||
|
|
|
||
|
|
return string(b)
|
||
|
|
}
|