why does RC cache to the DB and local file? - Dev

7 Dec 2005


      In this code in func.inc, it looks like RC is caching a message both to the
database and to the local temp directory. Why does it cache 2 times?
// let's cache the message body within the database
  if ($CONFIG['enable_caching'] && $cached && ($CONFIG['db_max_length']
-300) > $headers->size)
    {
    $DB->query("UPDATE ".get_table_name('messages')."
                SET    body=?
                WHERE  user_id=?
                AND    cache_key=?
                AND    uid=?",
               $msg_source,
               $_SESSION['user_id'],
               $cache_key,
               $uid);
return $msg_source;
}


// create dir for caching
  if (!is_dir($cache_dir))
    $dir = mkdir($cache_dir);
  else
    $dir = true;
// attempt to write a file with the message body
  if ($dir && ($fp = fopen($cache_path, 'w')))
    {
    fwrite($fp, $msg_source);
    fclose($fp);
    }
  else
    {
    raise_error(array('code' => 403, 'type' => 'php', 'line' => __LINE__,
'file' => __FILE__,
                      'message' => "Failed to write to temp dir"), TRUE,
FALSE);
    }
return $msg_source;