[Owncloud] Calendar access - speed issues

[Jonathan]

Hi,

I'm trying to use owncloud in anger now, but have come across what seems 
to be a speed issue when viewing/retrieving/querying calendar data.

Essentially, I have now imported my calendar entries from my mobile 
phone (I have 15 years of calendar data history), and this has degraded 
the response times of the web-based calendar app and the DAV interface 
as used by the dmfs CalDAV Android app for example, to a point where 
they are effectively unusable.

Full details below, but essentially it appears that the calendar/DAV 
code is reading in *all* calendar events, then filtering/evaluating them 
in software, before returning just the subset that has been asked for. 
With this quantity of events, it's taking about a minute to crunch 
through that - and this affects the performance of the web interface as 
well as calendar sync via DAV.

I would have thought that a simple SELECT query could narrow down the 
data before having to crunch through it all - or am I missing something?

A profile of caldav.php's execution is here, showing just how many times 
each function call is called for the query below:
http://users.ninja.org.uk/~jonathan/caldav/webgrind-caldav.pdf

I have 4081 calendar entries, of which 291 are repeating events:
SELECT count(*) FROM owncloud.oc_calendar_objects WHERE calendarid=4;
   4081
SELECT count(*) from oc_calendar_objects where calendarid=4 and
     repeating=1;
   291

The issue is that when trying to view calendar events for a reasonable 
time period (e.g. the current month), it takes a very long time to 
return the results:

localhost$ time curl -k --data-binary @calendar_query.xml \
	-H "depth:1" -H "user-agent:caldav" \
	-H "content-type: application/xml" -D - \
	-X REPORT -u username \
	http://localhost/apps/calendar/caldav.php/calendars/username/main
[...]
real    1m0.854s
user    0m0.007s
sys     0m0.031s

(These are figures from just now; last night it returned the data in 37 
seconds, but for some reason it's taking longer at the moment)

The calendar query is asking for basically the current month's events:
<?xml version="1.0" encoding="utf-8" ?>
<C:calendar-query xmlns:D="DAV:"
                   xmlns:C="urn:ietf:params:xml:ns:caldav">
   <C:filter>
     <C:comp-filter name="VCALENDAR">
       <C:comp-filter name="VEVENT">
         <C:time-range start="20120401T000000Z"
                       end="20120501T000000Z"/>
       </C:comp-filter>
     </C:comp-filter>
   </C:filter>
   <D:prop>
     <D:getetag />
   </D:prop>
</C:calendar-query>


In actual fact, there are 34 events in this time period:
SELECT count(*) FROM owncloud.oc_calendar_objects WHERE calendarid=4 and 
startdate>'2012-04-01' and enddate<'2012-05-01';
    34
plus I expect the 291 repeating events would have to be evaluated, too - 
thus making a total of 325 events to process, not 4081. Still not 
insignificant, but in theory that should be over 10 times quicker!

I would have thought that the code could (should?) first of all ask the 
database for just those events in the relevant time period (plus perhaps 
all events with 'repeating=1', as they will need to be evaluated), 
rather than just grabbing all events.

Have I missed something?

Many thanks!

Jonathan