This commit has the effect of eliminating all of the non-UserActivity
database queries from the Tornado process -- at least in the uncached
case.
This is safe to do, if a bit fragile, since our Tornado code only
accesses these objects (as opposed to their IDs) in a few places that
are all fine with old data, and I don't expect us to add any new ones
soon:
* UserActivity logging, which I plan to move out of Tornado entirely
* Checking whether we're authenticated in our decorators (which could
be simplified -- the actual security check is just whether the
Django session object has a particular field)
* Checking the user realm for whether we should sync to the client
notices about their Zephyr mirror being up to date, which is quite
static and I think we can move out of this code path.
But implementation constraints around mapping the user_ids to
user_profile_ids mean that it makes sense to get the actual objects
for now.
This code is not what I want to do long-term. I expect we'll be able
to clean up the dual User/UserProfile nonsense once we integrate the
upcoming Django 1.5 release, with its support for pluggable User
models, and after that I change, I expect it'll be fairly easy to make
the Tornado code only work with the user ID, not the actual objects.
(imported from commit 82e25b62fd0e3af7c86040600c63a4deec7bec06)