mirror of
https://github.com/zrepl/zrepl.git
synced 2024-12-18 21:20:44 +01:00
6ac537210b
Unless we're using the global source for math/rand, (*rand.Rand).Read should not be called concurrently. We seed the rng in daemon.Run to avoid ambiguity or hiding global side effects inside packages. closes #414
39 lines
677 B
Go
39 lines
677 B
Go
package trace
|
|
|
|
import (
|
|
"encoding/base64"
|
|
"math/rand"
|
|
"strings"
|
|
|
|
"github.com/zrepl/zrepl/util/envconst"
|
|
)
|
|
|
|
var genIdNumBytes = envconst.Int("ZREPL_TRACE_ID_NUM_BYTES", 3)
|
|
|
|
func init() {
|
|
if genIdNumBytes < 1 {
|
|
panic("trace node id byte length must be at least 1")
|
|
}
|
|
}
|
|
|
|
func genID() string {
|
|
var out strings.Builder
|
|
enc := base64.NewEncoder(base64.RawStdEncoding, &out)
|
|
buf := make([]byte, genIdNumBytes)
|
|
for i := 0; i < len(buf); {
|
|
n, err := rand.Read(buf[i:])
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
i += n
|
|
}
|
|
n, err := enc.Write(buf[:])
|
|
if err != nil || n != len(buf) {
|
|
panic(err)
|
|
}
|
|
if err := enc.Close(); err != nil {
|
|
panic(err)
|
|
}
|
|
return out.String()
|
|
}
|