Get sum of cart quantity of all options for a configurable product on cart page

Question

I want to get sum of qty of all variations present in cart for a configurable product. For ex.- see below image--

'WHEY PROTEIN ISOLATE-WPI' is a configuration product. In cart it has 2 different variations with qty 1 and 2.

I want to get its total qty i.e 3 (1+2) on same page (cart page), how can I get it.

Although I can do it by looping for each item in cart but it will slow down the cart page, so if any one can suggest another way to do it.

Any idea ?

Answer 1

Try this without looping through the cart items.

$quote = Mage::getSingleton('checkout/session')->getQuote();
$product = Mage::getModel('catalog/product')->load($product_id);
$_item = $quote->getItemByProduct($product);
$qty = $_item->getQty();