ecmall中static变量的使用-model模型代码设计

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());
}
print_r($models[$model_hash]);
return $models[$model_hash];
}

/**
* 获取一个业务模型
*
* @param string $model_name
* @param array $params
* @param bool $is_new
* @return object
*/
function &bm($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];
}

class Model
{
function  __construct()
{
echo 'construct'.'<br>';
}
}

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]))
{
$model_name = ucfirst($model_name) . 'Model';
if ($is_new)
{
return new Model();
}
$models[$model_hash] =  new Model();
}
return $models[$model_hash];
}

$s = m('db', array('name'));
$s1 = m('db', array('name'));