/**
  * Load binary file data from a given file path
  *
  * @param $filePath
  * @return null|string
  */
 private function restoreFile($filePath)
 {
     try {
         for ($i = 0; $i < $this->_config->getHostRetryLimit(); ++$i) {
             /* We try an exclusive creation of the file. This is an atomic operation, it avoid locking mechanism */
             @fopen($filePath, 'x');
             if (false === ($fileData = file_get_contents($filePath))) {
                 return null;
             }
             return $fileData;
         }
     } catch (\Exception $e) {
         return null;
     }
 }