PrestaShop: Cart cache optimization

This howto will explain how to stop dozens of extra queries that are made by an empty cart and significantly speed-up PrestaShop 1.3.

Note: This howto applies only to PrestaShop 1.3.

Open classes/Cart.php and find

if ($this->_products AND !$refresh)
	return $this->_products;

and replace with:

// Product cache must be strictly compared to NULL, or else an empty cart will add dozens of queries
if ($this->_products !== NULL AND !$refresh) {
	// Return product row with specified ID if it exists
	if (is_int($id_product))
	{
		foreach ($this->_products as $product)
			if ($product['id_product'] == $id_product)
				return array($product);
		return array();
	}
	return $this->_products;
}

Find:

/**
 * Return cart products quantity
 *
 * @result integer Products quantity
 */
public	function nbProducts()

Before, add:

public static function cacheSomeAttributesLists($ipaList, $id_lang)
{
	$paImplode = array();
	foreach ($ipaList as $id_product_attribute)
		if (intval($id_product_attribute) AND !array_key_exists($id_product_attribute.'-'.$id_lang, self::$_attributesLists))
		{
			$paImplode[] = intval($id_product_attribute);
			self::$_attributesLists[intval($id_product_attribute).'-'.$id_lang] = array('attributes' => '', 'attributes_small' => '');
		}
	if (!count($paImplode))
		return;

	$result = Db::getInstance()->ExecuteS('
	SELECT pac.`id_product_attribute`, agl.`public_name` AS public_group_name, al.`name` AS attribute_name
	FROM `'._DB_PREFIX_.'product_attribute_combination` pac
	LEFT JOIN `'._DB_PREFIX_.'attribute` a ON a.`id_attribute` = pac.`id_attribute`
	LEFT JOIN `'._DB_PREFIX_.'attribute_group` ag ON ag.`id_attribute_group` = a.`id_attribute_group`
	LEFT JOIN `'._DB_PREFIX_.'attribute_lang` al ON (a.`id_attribute` = al.`id_attribute` AND al.`id_lang` = '.intval($id_lang).')
	LEFT JOIN `'._DB_PREFIX_.'attribute_group_lang` agl ON (ag.`id_attribute_group` = agl.`id_attribute_group` AND agl.`id_lang` = '.intval($id_lang).')
	WHERE pac.`id_product_attribute` IN ('.implode($paImplode, ',').')
	ORDER BY agl.`public_name` ASC');

	foreach ($result as $row)
	{
		self::$_attributesLists[$row['id_product_attribute'].'-'.$id_lang]['attributes'] .= $row['public_group_name'].' : '.$row['attribute_name'].', ';
		self::$_attributesLists[$row['id_product_attribute'].'-'.$id_lang]['attributes_small'] .= $row['attribute_name'].', ';
	}

	foreach ($paImplode as $id_product_attribute)
	{
		self::$_attributesLists[$id_product_attribute.'-'.$id_lang]['attributes'] = rtrim(self::$_attributesLists[$id_product_attribute.'-'.$id_lang]['attributes'], ', ');
		self::$_attributesLists[$id_product_attribute.'-'.$id_lang]['attributes_small'] = rtrim(self::$_attributesLists[$id_product_attribute.'-'.$id_lang]['attributes_small'], ', ');
	}
}

Find:

public static function getNbProducts($id)
{
	if (self::$_nbProducts > 0)
		return self::$_nbProducts;
	self::$_nbProducts = intval(Db::getInstance()->getValue('SELECT SUM(`quantity`) FROM `'._DB_PREFIX_.'cart_product` WHERE `id_cart` = '.intval($id)));
	return self::$_nbProducts;

Replace with:

public static function getNbProducts($id)
{
	// Must be strictly compared to NULL, or else an empty cart will bypass the cache and add dozens of queries
	if (isset(self::$_nbProducts[$id]) && self::$_nbProducts[$id] !== NULL)
		return self::$_nbProducts[$id];
	self::$_nbProducts[$id] = intval(Db::getInstance()->getValue('
		SELECT SUM(`quantity`)
		FROM `'._DB_PREFIX_.'cart_product`
		WHERE `id_cart` = '.intval($id)));
	return self::$_nbProducts[$id];
}

Open class/Product.php file:

Find:

/**
* Admin panel product search
*
* @param integer $id_lang Language id
* @param string $query Search query
* @return array Matching products
*/
static public function searchByName($id_lang, $query)

Before, add:

public static function cacheProductsFeatures($productIds)
{
	$productImplode = array();
	foreach ($productIds as $id_product)
		if (intval($id_product) AND !array_key_exists($id_product, self::$_cacheFeatures))
			$productImplode[] = intval($id_product);
	if (!count($productImplode))
		return;

	$result = Db::getInstance()->ExecuteS('
	SELECT id_feature, id_product, id_feature_value
	FROM `'._DB_PREFIX_.'feature_product`
	WHERE `id_product` IN ('.implode($productImplode, ',').')');
	foreach ($result as $row)
	{
		if (!array_key_exists($row['id_product'], self::$_cacheFeatures))
			self::$_cacheFeatures[$row['id_product']] = array();
		self::$_cacheFeatures[$row['id_product']][] = $row;
	}
}

Save and close all files and it’s done.