Steve Howell a331b4f64d Optimize query_all_subs_by_stream(). ...

Using lightweight objects will speed up adding new users
to realms.

We also sort the query results, which lets us itertools.groupby
to more efficiently build the data structure.

Profiling on a large data set shows about a 25x speedup for this
function, and before the optimization, this function accounts
for most of the time spend in bulk_add_subscriptions.

There's a lot less memory to allocate.  I didn't measure
the memory difference.

When we test-deployed this to chat.zulip.org, we got about a 6x
speedup.

2017-10-06 11:03:44 -07:00

165 KiB

Raw Blame History

View Raw