Notify appservices of invites mid-poll.

This requires the notifier to have knowledge of appservice listeners so it can
do the regex checks on incoming invites to see if the state_key matches. It
isn't enough to just rely on the room listeners and store.get_app_service_rooms
as the room will initially not exist or won't be on the ASes radar due to
having none of its users in the room.

synapse/notifier.py

@@ -36,8 +36,10 @@ class _NotificationListener(object):
     so that it can remove itself from the indexes in the Notifier class.
     """
 
-    def __init__(self, user, rooms, from_token, limit, timeout, deferred):
+    def __init__(self, user, rooms, from_token, limit, timeout, deferred,
+                 appservice=None):
         self.user = user
+        self.appservice = appservice
         self.from_token = from_token
         self.limit = limit
         self.timeout = timeout
@@ -65,6 +67,10 @@ class _NotificationListener(object):
             lst.discard(self)
 
         notifier.user_to_listeners.get(self.user, set()).discard(self)
+        if self.appservice:
+            notifier.appservice_to_listeners.get(
+                self.appservice, set()
+            ).discard(self)
 
 
 class Notifier(object):
@@ -79,6 +85,7 @@ class Notifier(object):
 
         self.rooms_to_listeners = {}
         self.user_to_listeners = {}
+        self.appservice_to_listeners = {}
 
         self.event_sources = hs.get_event_sources()
 
@@ -114,6 +121,17 @@ class Notifier(object):
         for user in extra_users:
             listeners |= self.user_to_listeners.get(user, set()).copy()
 
+        for appservice in self.appservice_to_listeners:
+            # TODO (kegan): Redundant appservice listener checks?
+            # App services will already be in the rooms_to_listeners set, but
+            # that isn't enough. They need to be checked here in order to
+            # receive *invites* for users they are interested in. Does this
+            # make the rooms_to_listeners check somewhat obselete?
+            if appservice.is_interested(event):
+                listeners |= self.appservice_to_listeners.get(
+                    appservice, set()
+                ).copy()
+
         logger.debug("on_new_room_event listeners %s", listeners)
 
         # TODO (erikj): Can we make this more efficient by hitting the
@@ -280,6 +298,10 @@ class Notifier(object):
         if not from_token:
             from_token = yield self.event_sources.get_current_token()
 
+        appservice = yield self.hs.get_datastore().get_app_service_by_user_id(
+            user.to_string()
+        )
+
         listener = _NotificationListener(
             user,
             rooms,
@@ -287,6 +309,7 @@ class Notifier(object):
             limit,
             timeout,
             deferred,
+            appservice=appservice
         )
 
         def _timeout_listener():
@@ -319,6 +342,11 @@ class Notifier(object):
 
         self.user_to_listeners.setdefault(listener.user, set()).add(listener)
 
+        if listener.appservice:
+            self.appservice_to_listeners.setdefault(
+                listener.appservice, set()
+            ).add(listener)
+
     @defer.inlineCallbacks
     @log_function
     def _check_for_updates(self, listener):