message: Add some useful functions.
diff: <?php
  +
  +function var_dump_return(...$data): string
  +{
  + ob_start();
  + foreach ($data as $d){
  + var_dump($d);
  + }
  + return ob_get_clean();
  +}
  +
  +function get_safe_random(int $length = 32, $original = false): string
  +{
  + $raw = base64_encode(openssl_random_pseudo_bytes($original ? $length : $length * 2));
  + if (!$original) {
  + $raw = substr(str_replace(['/', '+', '='], '', $raw), 0, $length);
  + }
  + return $raw;
  +}
  +
  function swoole_php_fork($func, $out = false) {
  $process = new swoole_process($func, $out);
  $pid = $process->start();
  @@ -63,7 +82,6 @@ function makeTcpClient($host, $port, callable $onConnect = null, callable $onRec
  $cli->connect($host, $port);
  }
  -
  function opcode_encode($op, $data)
  {
  $r = json_encode([$op, $data]);
  