/**
* choose master or slave
*
* @param string $sql
*/
private static function _switch($sql)
{
$select = false;
$uid = Login::GetCurrentUserId();
$callback = 'DB::_switch';
$args = array($uid);
$key = Memcache::GetFunctionKey($callback, $args);
if (false === stripos($sql, 'SELECT')) {
if ($uid) {
// master
$flag = 0;
$value = 1;
Memcache::Instance()->Set($key, $value, $flag, self::$life);
}
} elseif (rand(0, 1)) {
// %50 to master
} else {
$value = Memcache::Instance()->Get($key);
if (!$value) {
//slave
$select = 1;
}
}
return self::_getConn($select);
}
