/**
  * Converts the logging event into an array which can be logged to mongodb.
  * 
  * @param Ideasa_Log4php_LoggerLoggingEvent $event
  * @return array The array representation of the logging event.
  */
 protected function format(Ideasa_Log4php_LoggerLoggingEvent $event)
 {
     $timestampSec = (int) $event->getTimestamp();
     $timestampUsec = (int) (($event->getTimestamp() - $timestampSec) * 1000000);
     $document = array('timestamp' => new MongoDate($timestampSec, $timestampUsec), 'level' => $event->getLevel()->toString(), 'thread' => (int) $event->getThreadName(), 'message' => $event->getMessage(), 'loggerName' => $event->getLoggerName());
     $locationInfo = $event->getLocationInformation();
     if ($locationInfo != null) {
         $document['fileName'] = $locationInfo->getFileName();
         $document['method'] = $locationInfo->getMethodName();
         $document['lineNumber'] = $locationInfo->getLineNumber() == 'NA' ? 'NA' : (int) $locationInfo->getLineNumber();
         $document['className'] = $locationInfo->getClassName();
     }
     $throwableInfo = $event->getThrowableInformation();
     if ($throwableInfo != null) {
         $document['exception'] = $this->formatThrowable($throwableInfo->getThrowable());
     }
     return $document;
 }