perf: Weed out disabled variants via sql query instead of pythonic looping separately

- If the number of variants are large (almost 2lakhs), the query to get variants and attribute data takes time
- If the no.of disabled attributes is large as well, the list comprehension weeding out disabled variants takes forever
- We dont need to loop over the variants data so many times
- Avoid any `if a in list(b)` is best when the iterables have tremendous data

erpnext/e_commerce/variant_selector/item_variants_cache.py

@@ -66,25 +66,39 @@ class ItemVariantsCacheManager:
 			)
 		]
 
-		# join with Website Item
-		item_variants_data = frappe.get_all(
-			'Item Variant Attribute',
-			{'variant_of': parent_item_code},
-			['parent', 'attribute', 'attribute_value'],
-			order_by='name',
-			as_list=1
+		# Get Variants and tehir Attributes that are not disabled
+		iva = frappe.qb.DocType("Item Variant Attribute")
+		item = frappe.qb.DocType("Item")
+		query = (
+			frappe.qb.from_(iva)
+			.join(item).on(item.name == iva.parent)
+			.select(
+				iva.parent, iva.attribute, iva.attribute_value
+			).where(
+				(iva.variant_of == parent_item_code)
+				& (item.disabled == 0)
+			).orderby(iva.name)
 		)
+		item_variants_data = query.run()
 
-		disabled_items = set(
-			[i.name for i in frappe.db.get_all('Item', {'disabled': 1})]
-		)
+		# item_variants_data = frappe.get_all(
+		# 	'Item Variant Attribute',
+		# 	{'variant_of': parent_item_code},
+		# 	['parent', 'attribute', 'attribute_value'],
+		# 	order_by='name',
+		# 	as_list=1
+		# )
+
+		# disabled_items = set(
+		# 	[i.name for i in frappe.db.get_all('Item', {'disabled': 1})]
+		# )
 
 		attribute_value_item_map = frappe._dict()
 		item_attribute_value_map = frappe._dict()
 
 		# dont consider variants that are disabled
 		# pull all other variants
-		item_variants_data = [r for r in item_variants_data if r[0] not in disabled_items]
+		# item_variants_data = [r for r in item_variants_data if r[0] not in disabled_items]
 
 		for row in item_variants_data:
 			item_code, attribute, attribute_value = row