function __construct($callback = null, $ttl = -1)
{
//Maximum entropy, minimum data
$this->id = \Radical\Basic\String\Random::GenerateBase64(6) . dechex(crc32(session_id() . time()));
$len = strlen($this->id) - rand(0, 4);
$this->id = substr($this->id, 0, $len);
$this->key = \Radical\Basic\String\Random::GenerateBytes(32);
$this->callback = $callback;
if ($ttl > 0) {
$this->expires = $ttl + time();
}
KeyStorage::AddKey($this);
}
