Rate Limit and Exponential Decay

We implement rate limit protection in our API. To protect your App or a user from being blocked we strongly suggest that you implement an exponential decay in the event of any request failures.

Below is an example of such a decay in PHP:

$response = false;
$delay = 0.5; // seconds
$maxDelay = 2; // seconds
while(true) {
   $response = curl_exec($curl);
   // var_dump(curl_getinfo($curl)); // use for debugging
   if ($response !== false) {
      curl_close($curl);
      break;
   } else {
      $seconds = intval($delay);
      $nanoseconds = ($delay - $seconds) * 1e9;
      time_nanosleep($seconds, $nanoseconds);
      $delay *= 2;
      if ($delay = $maxDelay) {
         $error = curl_error($curl);
         $errno = curl_errno($curl);
         fail('Error: ' . $error . ', Errno: ' . $errno);
         curl_close($curl);
         return false;
      }
   }
}