From 1e05a1cd727fac75d9df04cd5f852b551f792529 Mon Sep 17 00:00:00 2001
From: Roman <roman.kysil@redturtle.it>
Date: Wed, 10 Jan 2024 11:36:11 +0100
Subject: [PATCH] Fix @available-slots view performance

---
 CHANGES.rst                                         | 3 +++
 src/redturtle/prenotazioni/adapters/booking_code.py | 7 ++++---
 src/redturtle/prenotazioni/utilities/dateutils.py   | 9 ++++++++-
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index 4f8676ae..23cb833a 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -5,6 +5,9 @@ Changelog
 2.4.0 (unreleased)
 ------------------
 
+- Perfomance refactoring for @available-slots view
+  [folix-01]
+
 - Split booking notification gateways to 'App IO', 'Email' and 'SMS'
   [folix-01]
 
diff --git a/src/redturtle/prenotazioni/adapters/booking_code.py b/src/redturtle/prenotazioni/adapters/booking_code.py
index 1c6ec0e0..dfaaecdb 100644
--- a/src/redturtle/prenotazioni/adapters/booking_code.py
+++ b/src/redturtle/prenotazioni/adapters/booking_code.py
@@ -1,10 +1,11 @@
 # -*- coding: utf-8 -*-
-from redturtle.prenotazioni.content.prenotazione import IPrenotazione
-from zope.component import adapter
+import hashlib
+
 from zope.component import Interface
+from zope.component import adapter
 from zope.interface import implementer
 
-import hashlib
+from redturtle.prenotazioni.content.prenotazione import IPrenotazione
 
 
 class IBookingCodeGenerator(Interface):
diff --git a/src/redturtle/prenotazioni/utilities/dateutils.py b/src/redturtle/prenotazioni/utilities/dateutils.py
index 7f721f71..60605ddb 100644
--- a/src/redturtle/prenotazioni/utilities/dateutils.py
+++ b/src/redturtle/prenotazioni/utilities/dateutils.py
@@ -4,11 +4,18 @@
 from datetime import timedelta
 
 import six
+from cachetools import TTLCache
+from cachetools import cached
 from plone.app.event.base import default_timezone
 
 from redturtle.prenotazioni import tznow
 
 
+@cached(cache=TTLCache(maxsize=10, ttl=timedelta(hours=1), timer=datetime.now))
+def get_default_timezone(as_tzinfo):
+    return default_timezone(as_tzinfo=as_tzinfo)
+
+
 def hm2handm(hm):
     """This is a utility function that will return the hour and date of day
     to the value passed in the string hm
@@ -33,7 +40,7 @@ def hm2DT(day, hm, tzinfo=None):
     :param tzinfo: a timezone object (default: the default local timezone as in plone)
     """
     if tzinfo is None:
-        tzinfo = default_timezone(as_tzinfo=True)
+        tzinfo = get_default_timezone(as_tzinfo=True)
 
     if not hm or hm == "--NOVALUE--" or hm == ("--NOVALUE--",):
         return None