[CalendarServer-dev] Does timezones have to be so slow?

[Peter Mogensen]

Hi,

I'm experiencing slow REPORT/calendar-query responses on medium large 
calendars.
calendarserver is spending a lot of time adding VTIMEZONE components to 
VEVENTS - and sadly it seems to be the same calculations done every time 
(all events are the same timezone).
tzinfo is cached by vobject (helped by timezones.py), but the settzinfo 
method on TimezoneComponent is still doing the same job again and again.

It would seem obvious to me to cache TimezoneComponent objects, maybe 
with a validity tag, which gives you the valid timerange for this 
VTIMEZONE component.
This might also help get around the problem that vobject only expands 
timezone defs from 2000 to 2030

Any gotcha, I've overlooked which explains why TimezoneComponents are 
not already cached?

/P