Fix config file caching

fabcal/calendar_client.py

@@ -10,7 +10,7 @@ import recurring_ical_events
 import yaml
 
 from asyncache import cached
-from cachetools import TTLCache, LRUCache
+from cachetools import TTLCache, FIFOCache
 from icalendar import Calendar
 
 from fabcal.models import CalendarEvent
@@ -35,20 +35,23 @@ class CalendarClient:
 
 
 # this will be cached permanently, i.e., the server process needs to be restarted to apply config changes
-@cached(LRUCache(100))
-def read_calendars_from_config_file():
+# note that caching doesn't work at all with iterators (for obvious reasons)
+@cached(FIFOCache(1))
+def read_calendars_from_config_file() -> List[ConfiguredCalendar]:
+    rv = []
+
     with open("config.yml") as f:
         data = yaml.safe_load(f)
 
         for calendar in data["calendars"]:
-            yield ConfiguredCalendar(**calendar)
+            rv.append(ConfiguredCalendar(**calendar))
 
+    return rv
 
 
 class CombinedCalendarClient:
     def __init__(self, configured_calendars: List[ConfiguredCalendar]):
-        # make sure it's a list since read_calendars_from_config_file() returns an iterator
-        self.configured_calendars = list(configured_calendars)
+        self.configured_calendars = configured_calendars
 
     async def fetch_calendars(self) -> Dict[ConfiguredCalendar, str]:
         async with aiohttp.ClientSession() as session: