client-barcode: Add an item cache

client-barcode/freitagskasse.py

@@ -56,6 +56,7 @@ def error_page(message):
 class Status:
 	def __init__(self):
 		self._reset()
+		self.item_cache = dict()
 
 	def _reset(self):
 		self.auth_blob = None
@@ -122,7 +123,12 @@ class Status:
 		self._reset()
 
 	def find(self, item_id):
-		return net.get_item(item_id)
+		try:
+			return self.item_cache[item_id]
+		except KeyError:
+			item = net.get_item(item_id)
+			self.item_cache[item_id] = item
+			return item
 
 	def buy(self, item):
 		assert(self.logged_in())