src/client/pps.go
func DatumTagPrefix(salt string) string {
	// We need to hash the salt because UUIDs are not necessarily
	// random in every bit.
	h := sha256.New()
	h.Write([]byte(salt))
	return hex.EncodeToString(h.Sum(nil))[:4]
}
func DatumTagPrefix(salt string) string {
	// We need to hash the salt because UUIDs are not necessarily
	// random in every bit.
	h := sha256.New()
	h.Write([]byte(salt))
	return hex.EncodeToString(h.Sum(nil))[:4]
}
// DatumTagPrefix hashes a pipeline salt to a string of a fixed size for use as
// the prefix for datum output trees. This prefix allows us to do garbage
// collection correctly.