// genNewID generates a new, unique device ID
func genNewRandID(p *page.Params, d *ds.Device) {
b := make([]byte, 9) // Use 9 bytes: multiple of 3 bytes (ideal for base64 encoding so no padding '=' signs will be needed)
if _, p.Err = rand.Read(b); p.Err != nil {
return
}
RandID := base64.URLEncoding.EncodeToString(b)
// Check if RandID is unique.
// It will be, but once in a million years we might maybe perhaps encounter a match!
q := datastore.NewQuery(ds.ENameDevice).Filter(ds.PNameRandID+"=", RandID).KeysOnly().Limit(1)
var devKeys []*datastore.Key
if devKeys, p.Err = q.GetAll(p.AppCtx, nil); p.Err != nil {
return
}
if len(devKeys) > 0 {
p.Err = fmt.Errorf("Generated device RandID already exists: %s", RandID)
return
}
d.RandID = RandID
}
