Previous cleanups (mostly the removals of Python __future__ imports)
were done in a way that introduced leading newlines. Delete leading
newlines from all files, except static/assets/zulip-emoji/NOTICE,
which is a verbatim copy of the Apache 2.0 license.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
This class encapsulates the mapping of stream ids to
recipient ids, and it is optimized for bulk use and
repeated use (i.e. it remembers values it already fetched).
This particular commit barely improves the performance
of gather_subscriptions_helper, but it sets us up for
further optimizations.
Long term, we may try to denormalize stream_id on to the
Subscriber table or otherwise modify the database so we
don't have to jump through hoops to do this kind of mapping.
This commit will help enable those changes, because we
isolate the mapping to this one new class.
Anders Kaseorg
rht
Steve Howell