Merge pull request #3621 from matrix-org/erikj/split_fed_store

Split out DB writes in federation handler

changelog.d/3621.misc

@@ -0,0 +1 @@
+Refactor FederationHandler to move DB writes into separate functions

synapse/handlers/federation.py

@@ -400,7 +400,7 @@ class FederationHandler(BaseHandler):
             )
 
             try:
-                event_stream_id, max_stream_id = yield self._persist_auth_tree(
+                yield self._persist_auth_tree(
                     origin, auth_chain, state, event
                 )
             except AuthError as e:
@@ -444,7 +444,7 @@ class FederationHandler(BaseHandler):
                 yield self._handle_new_events(origin, event_infos)
 
             try:
-                context, event_stream_id, max_stream_id = yield self._handle_new_event(
+                context = yield self._handle_new_event(
                     origin,
                     event,
                     state=state,
@@ -469,17 +469,6 @@ class FederationHandler(BaseHandler):
             except StoreError:
                 logger.exception("Failed to store room.")
 
-        extra_users = []
-        if event.type == EventTypes.Member:
-            target_user_id = event.state_key
-            target_user = UserID.from_string(target_user_id)
-            extra_users.append(target_user)
-
-        self.notifier.on_new_room_event(
-            event, event_stream_id, max_stream_id,
-            extra_users=extra_users
-        )
-
         if event.type == EventTypes.Member:
             if event.membership == Membership.JOIN:
                 # Only fire user_joined_room if the user has acutally
@@ -501,7 +490,7 @@ class FederationHandler(BaseHandler):
 
                 if newly_joined:
                     user = UserID.from_string(event.state_key)
-                    yield user_joined_room(self.distributor, user, event.room_id)
+                    yield self.user_joined_room(user, event.room_id)
 
     @log_function
     @defer.inlineCallbacks
@@ -942,7 +931,7 @@ class FederationHandler(BaseHandler):
 
         self.room_queues[room_id] = []
 
-        yield self.store.clean_room_for_join(room_id)
+        yield self._clean_room_for_join(room_id)
 
         handled_events = set()
 
@@ -981,15 +970,10 @@ class FederationHandler(BaseHandler):
                 # FIXME
                 pass
 
-            event_stream_id, max_stream_id = yield self._persist_auth_tree(
+            yield self._persist_auth_tree(
                 origin, auth_chain, state, event
             )
 
-            self.notifier.on_new_room_event(
-                event, event_stream_id, max_stream_id,
-                extra_users=[joinee]
-            )
-
             logger.debug("Finished joining %s to %s", joinee, room_id)
         finally:
             room_queue = self.room_queues[room_id]
@@ -1084,7 +1068,7 @@ class FederationHandler(BaseHandler):
         # would introduce the danger of backwards-compatibility problems.
         event.internal_metadata.send_on_behalf_of = origin
 
-        context, event_stream_id, max_stream_id = yield self._handle_new_event(
+        context = yield self._handle_new_event(
             origin, event
         )
 
@@ -1094,20 +1078,10 @@ class FederationHandler(BaseHandler):
             event.signatures,
         )
 
-        extra_users = []
-        if event.type == EventTypes.Member:
-            target_user_id = event.state_key
-            target_user = UserID.from_string(target_user_id)
-            extra_users.append(target_user)
-
-        self.notifier.on_new_room_event(
-            event, event_stream_id, max_stream_id, extra_users=extra_users
-        )
-
         if event.type == EventTypes.Member:
             if event.content["membership"] == Membership.JOIN:
                 user = UserID.from_string(event.state_key)
-                yield user_joined_room(self.distributor, user, event.room_id)
+                yield self.user_joined_room(user, event.room_id)
 
         prev_state_ids = yield context.get_prev_state_ids(self.store)
 
@@ -1176,17 +1150,7 @@ class FederationHandler(BaseHandler):
         )
 
         context = yield self.state_handler.compute_event_context(event)
-
+        yield self._persist_events([(event, context)])
-        event_stream_id, max_stream_id = yield self.store.persist_event(
-            event,
-            context=context,
-        )
-
-        target_user = UserID.from_string(event.state_key)
-        self.notifier.on_new_room_event(
-            event, event_stream_id, max_stream_id,
-            extra_users=[target_user],
-        )
 
         defer.returnValue(event)
 
@@ -1217,17 +1181,7 @@ class FederationHandler(BaseHandler):
         )
 
         context = yield self.state_handler.compute_event_context(event)
-
+        yield self._persist_events([(event, context)])
-        event_stream_id, max_stream_id = yield self.store.persist_event(
-            event,
-            context=context,
-        )
-
-        target_user = UserID.from_string(event.state_key)
-        self.notifier.on_new_room_event(
-            event, event_stream_id, max_stream_id,
-            extra_users=[target_user],
-        )
 
         defer.returnValue(event)
 
@@ -1318,7 +1272,7 @@ class FederationHandler(BaseHandler):
 
         event.internal_metadata.outlier = False
 
-        context, event_stream_id, max_stream_id = yield self._handle_new_event(
+        yield self._handle_new_event(
             origin, event
         )
 
@@ -1328,16 +1282,6 @@ class FederationHandler(BaseHandler):
             event.signatures,
         )
 
-        extra_users = []
-        if event.type == EventTypes.Member:
-            target_user_id = event.state_key
-            target_user = UserID.from_string(target_user_id)
-            extra_users.append(target_user)
-
-        self.notifier.on_new_room_event(
-            event, event_stream_id, max_stream_id, extra_users=extra_users
-        )
-
         defer.returnValue(None)
 
     @defer.inlineCallbacks
@@ -1472,9 +1416,8 @@ class FederationHandler(BaseHandler):
                     event, context
                 )
 
-            event_stream_id, max_stream_id = yield self.store.persist_event(
+            yield self._persist_events(
-                event,
+                [(event, context)],
-                context=context,
                 backfilled=backfilled,
             )
         except:  # noqa: E722, as we reraise the exception this is fine.
@@ -1487,15 +1430,7 @@ class FederationHandler(BaseHandler):
 
             six.reraise(tp, value, tb)
 
-        if not backfilled:
+        defer.returnValue(context)
-            # this intentionally does not yield: we don't care about the result
-            # and don't need to wait for it.
-            logcontext.run_in_background(
-                self.pusher_pool.on_new_notifications,
-                event_stream_id, max_stream_id,
-            )
-
-        defer.returnValue((context, event_stream_id, max_stream_id))
 
     @defer.inlineCallbacks
     def _handle_new_events(self, origin, event_infos, backfilled=False):
@@ -1503,6 +1438,8 @@ class FederationHandler(BaseHandler):
         should not depend on one another, e.g. this should be used to persist
         a bunch of outliers, but not a chunk of individual events that depend
         on each other for state calculations.
+
+        Notifies about the events where appropriate.
         """
         contexts = yield logcontext.make_deferred_yieldable(defer.gatherResults(
             [
@@ -1517,7 +1454,7 @@ class FederationHandler(BaseHandler):
             ], consumeErrors=True,
         ))
 
-        yield self.store.persist_events(
+        yield self._persist_events(
             [
                 (ev_info["event"], context)
                 for ev_info, context in zip(event_infos, contexts)
@@ -1529,7 +1466,8 @@ class FederationHandler(BaseHandler):
     def _persist_auth_tree(self, origin, auth_events, state, event):
         """Checks the auth chain is valid (and passes auth checks) for the
         state and event. Then persists the auth chain and state atomically.
-        Persists the event seperately.
+        Persists the event separately. Notifies about the persisted events
+        where appropriate.
 
         Will attempt to fetch missing auth events.
 
@@ -1540,8 +1478,7 @@ class FederationHandler(BaseHandler):
             event (Event)
 
         Returns:
-            2-tuple of (event_stream_id, max_stream_id) from the persist_event
+            Deferred
-            call for `event`
         """
         events_to_context = {}
         for e in itertools.chain(auth_events, state):
@@ -1605,7 +1542,7 @@ class FederationHandler(BaseHandler):
                     raise
                 events_to_context[e.event_id].rejected = RejectedReason.AUTH_ERROR
 
-        yield self.store.persist_events(
+        yield self._persist_events(
             [
                 (e, events_to_context[e.event_id])
                 for e in itertools.chain(auth_events, state)
@@ -1616,12 +1553,10 @@ class FederationHandler(BaseHandler):
             event, old_state=state
         )
 
-        event_stream_id, max_stream_id = yield self.store.persist_event(
+        yield self._persist_events(
-            event, new_event_context,
+            [(event, new_event_context)],
         )
 
-        defer.returnValue((event_stream_id, max_stream_id))
-
     @defer.inlineCallbacks
     def _prep_event(self, origin, event, state=None, auth_events=None):
         """
@@ -2347,3 +2282,69 @@ class FederationHandler(BaseHandler):
             )
         if "valid" not in response or not response["valid"]:
             raise AuthError(403, "Third party certificate was invalid")
+
+    @defer.inlineCallbacks
+    def _persist_events(self, event_and_contexts, backfilled=False):
+        """Persists events and tells the notifier/pushers about them, if
+        necessary.
+
+        Args:
+            event_and_contexts(list[tuple[FrozenEvent, EventContext]])
+            backfilled (bool): Whether these events are a result of
+                backfilling or not
+
+        Returns:
+            Deferred
+        """
+        max_stream_id = yield self.store.persist_events(
+            event_and_contexts,
+            backfilled=backfilled,
+        )
+
+        if not backfilled:  # Never notify for backfilled events
+            for event, _ in event_and_contexts:
+                self._notify_persisted_event(event, max_stream_id)
+
+    def _notify_persisted_event(self, event, max_stream_id):
+        """Checks to see if notifier/pushers should be notified about the
+        event or not.
+
+        Args:
+            event (FrozenEvent)
+            max_stream_id (int): The max_stream_id returned by persist_events
+        """
+
+        extra_users = []
+        if event.type == EventTypes.Member:
+            target_user_id = event.state_key
+
+            # We notify for memberships if its an invite for one of our
+            # users
+            if event.internal_metadata.is_outlier():
+                if event.membership != Membership.INVITE:
+                    if not self.is_mine_id(target_user_id):
+                        return
+
+            target_user = UserID.from_string(target_user_id)
+            extra_users.append(target_user)
+        elif event.internal_metadata.is_outlier():
+            return
+
+        event_stream_id = event.internal_metadata.stream_ordering
+        self.notifier.on_new_room_event(
+            event, event_stream_id, max_stream_id,
+            extra_users=extra_users
+        )
+
+        logcontext.run_in_background(
+            self.pusher_pool.on_new_notifications,
+            event_stream_id, max_stream_id,
+        )
+
+    def _clean_room_for_join(self, room_id):
+        return self.store.clean_room_for_join(room_id)
+
+    def user_joined_room(self, user, room_id):
+        """Called when a new user has joined the room
+        """
+        return user_joined_room(self.distributor, user, room_id)

synapse/storage/events.py

@@ -241,12 +241,18 @@ class EventsStore(EventFederationStore, EventsWorkerStore, BackgroundUpdateStore
 
         self._state_resolution_handler = hs.get_state_resolution_handler()
 
+    @defer.inlineCallbacks
     def persist_events(self, events_and_contexts, backfilled=False):
         """
         Write events to the database
         Args:
             events_and_contexts: list of tuples of (event, context)
-            backfilled: ?
+            backfilled (bool): Whether the results are retrieved from federation
+                via backfill or not. Used to determine if they're "new" events
+                which might update the current state etc.
+
+        Returns:
+            Deferred[int]: the stream ordering of the latest persisted event
         """
         partitioned = {}
         for event, ctx in events_and_contexts:
@@ -263,10 +269,14 @@ class EventsStore(EventFederationStore, EventsWorkerStore, BackgroundUpdateStore
         for room_id in partitioned:
             self._maybe_start_persisting(room_id)
 
-        return make_deferred_yieldable(
+        yield make_deferred_yieldable(
             defer.gatherResults(deferreds, consumeErrors=True)
         )
 
+        max_persisted_id = yield self._stream_id_gen.get_current_token()
+
+        defer.returnValue(max_persisted_id)
+
     @defer.inlineCallbacks
     @log_function
     def persist_event(self, event, context, backfilled=False):