function &m($model_name, $params = array(), $is_new = false) {static $models = array();$model_hash = md5($model_name . var_export($params, true));if ($is_new || !isset($models[$model_hash]))   {$model_file = ROOT_PATH . ‘/includes/models/’ . $model_name .‘.model.php’;if (!is_file($model_file)){/* 不存在该文件，则无法获取模型 */return false;}include_once($model_file);$model_name = ucfirst($model_name) . ‘Model’;if ($is_new){return new $model_name($params, db());}$models[$model_hash] = new $model_name($params, db());}return $models[$model_hash];}//获取一个业务模型function &bm($model_name, $params = array(), $is_new = false){static $models = array();$model_hash = md5($model_name . var_export($params, true));if ($is_new || !isset($models[$model_hash])){$model_file = ROOT_PATH . ‘/includes/models/’ . $model_name .‘.model.php’;if (!is_file($model_file)){/* 不存在该文件，则无法获取模型 */return false;}include_once($model_file);$model_name = ucfirst($model_name) . ‘BModel’;if ($is_new){return new $model_name($params, db());}$models[$model_hash] = new $model_name($params, db());}return $models[$model_hash];}