private static function _getMemcachePrefix()
{
if (!isset(self::$_cacheNamespace)) {
$mc = self::getMemcache();
//namespace is incremented in Kwf_Util_ClearCache
//use memcache directly as Zend would not save the integer directly and we can't increment it then
$v = $mc->get(self::getUniquePrefix() . 'cache_namespace');
if (!$v) {
$v = time();
$mc->set(self::getUniquePrefix() . 'cache_namespace', $v);
}
self::$_cacheNamespace = self::getUniquePrefix() . '-' . $v;
}
return self::$_cacheNamespace;
}