Remove the is_new_state argument to persist event.

Move the checks for whether an event is new state inside persist
event itself.

This was harder than expected because there wasn't enough information
passed to persist event to correctly handle invites from remote servers
for new rooms.

synapse/storage/events.py

@@ -61,8 +61,7 @@ class EventsStore(SQLBaseStore):
         )
 
     @defer.inlineCallbacks
-    def persist_events(self, events_and_contexts, backfilled=False,
-                       is_new_state=True):
+    def persist_events(self, events_and_contexts, backfilled=False):
         if not events_and_contexts:
             return
 
@@ -110,13 +109,11 @@ class EventsStore(SQLBaseStore):
                         self._persist_events_txn,
                         events_and_contexts=chunk,
                         backfilled=backfilled,
-                        is_new_state=is_new_state,
                     )
 
     @defer.inlineCallbacks
     @log_function
-    def persist_event(self, event, context,
-                      is_new_state=True, current_state=None):
+    def persist_event(self, event, context, current_state=None):
 
         try:
             with self._stream_id_gen.get_next() as stream_ordering:
@@ -128,7 +125,6 @@ class EventsStore(SQLBaseStore):
                         self._persist_event_txn,
                         event=event,
                         context=context,
-                        is_new_state=is_new_state,
                         current_state=current_state,
                     )
         except _RollbackButIsFineException:
@@ -194,8 +190,7 @@ class EventsStore(SQLBaseStore):
         defer.returnValue({e.event_id: e for e in events})
 
     @log_function
-    def _persist_event_txn(self, txn, event, context,
-                           is_new_state, current_state):
+    def _persist_event_txn(self, txn, event, context, current_state):
         # We purposefully do this first since if we include a `current_state`
         # key, we *want* to update the `current_state_events` table
         if current_state:
@@ -236,12 +231,10 @@ class EventsStore(SQLBaseStore):
             txn,
             [(event, context)],
             backfilled=False,
-            is_new_state=is_new_state,
         )
 
     @log_function
-    def _persist_events_txn(self, txn, events_and_contexts, backfilled,
-                            is_new_state):
+    def _persist_events_txn(self, txn, events_and_contexts, backfilled):
         depth_updates = {}
         for event, context in events_and_contexts:
             # Remove the any existing cache entries for the event_ids
@@ -452,10 +445,9 @@ class EventsStore(SQLBaseStore):
             txn, [event for event, _ in events_and_contexts]
         )
 
-        state_events_and_contexts = filter(
-            lambda i: i[0].is_state(),
-            events_and_contexts,
-        )
+        state_events_and_contexts = [
+            ec for ec in events_and_contexts if ec[0].is_state()
+        ]
 
         state_values = []
         for event, context in state_events_and_contexts:
@@ -493,32 +485,50 @@ class EventsStore(SQLBaseStore):
             ],
         )
 
-        if is_new_state:
-            for event, _ in state_events_and_contexts:
-                if not context.rejected:
-                    txn.call_after(
-                        self._get_current_state_for_key.invalidate,
-                        (event.room_id, event.type, event.state_key,)
-                    )
+        for event, _ in state_events_and_contexts:
+            if backfilled:
+                # Backfilled events come before the current state so shouldn't
+                # clobber it.
+                continue
 
-                    if event.type in [EventTypes.Name, EventTypes.Aliases]:
-                        txn.call_after(
-                            self.get_room_name_and_aliases.invalidate,
-                            (event.room_id,)
-                        )
+            if (not event.internal_metadata.is_invite_from_remote()
+                    and event.internal_metadata.is_outlier()):
+                # Outlier events generally shouldn't clobber the current state.
+                # However invites from remote severs for rooms we aren't in
+                # are a bit special: they don't come with any associated
+                # state so are technically an outlier, however all the
+                # client-facing code assumes that they are in the current
+                # state table so we insert the event anyway.
+                continue
 
-                    self._simple_upsert_txn(
-                        txn,
-                        "current_state_events",
-                        keyvalues={
-                            "room_id": event.room_id,
-                            "type": event.type,
-                            "state_key": event.state_key,
-                        },
-                        values={
-                            "event_id": event.event_id,
-                        }
-                    )
+            if context.rejected:
+                # If the event failed it's auth checks then it shouldn't
+                # clobbler the current state.
+                continue
+
+            txn.call_after(
+                self._get_current_state_for_key.invalidate,
+                (event.room_id, event.type, event.state_key,)
+            )
+
+            if event.type in [EventTypes.Name, EventTypes.Aliases]:
+                txn.call_after(
+                    self.get_room_name_and_aliases.invalidate,
+                    (event.room_id,)
+                )
+
+            self._simple_upsert_txn(
+                txn,
+                "current_state_events",
+                keyvalues={
+                    "room_id": event.room_id,
+                    "type": event.type,
+                    "state_key": event.state_key,
+                },
+                values={
+                    "event_id": event.event_id,
+                }
+            )
 
         return