Curl stream and buffer webcam stuff, exit from CURLOPT_WRITEFUNCTION with own function

cam.php

<?php 
class CamStream {
  protected $code_done = 99999999;
  protected $buffer = "";

  public function start_stream($url="https://example.org", $passwd="hello:world") {
    $exit_ok = false;

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_DIGEST);
    curl_setopt($ch, CURLOPT_USERPWD, $passwd);
    curl_setopt($ch, CURLOPT_WRITEFUNCTION, array($this, 'my_stream_handler_func'));
      // curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_exec($ch);

    if(curl_errno($ch)){
      $exit_ok = strpos(curl_error($ch), "$this->code_done") !== false;
      if ($exit_ok) {
        curl_close($ch);
        return my_success_func();
      }
    }
    curl_close($ch);
    return $exit_ok;
  }

  protected function my_stream_handler_func($ch, $data) {
    // .. imagine our stream would contain "lorem", "ipsum", "dolor", "sit", "amet" repeatedly
    $buffer .= $data;

    if($buffer === "lorem ipsum dolor sit amet") {
      return $this->code_done;
    }

    return strlen($data);
  }
  
  protected function my_success_func() {
    // return true; // or whatevs
  }
}

$cam = new CamStream();
$success = $cam->start_stream();

var_dump($success);