Merge pull request #948 from matrix-org/markjh/auth_fixes

Don't add rejections to the state_group, persist all rejections

1 files changed, 110 insertions, 50 deletions

diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 6610549281..c63ca36df6 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -397,6 +397,12 @@ class EventsStore(SQLBaseStore):
 
     @log_function
     def _persist_events_txn(self, txn, events_and_contexts, backfilled):
+        """Insert some number of room events into the necessary database tables.
+
+        Rejected events are only inserted into the events table, the events_json table,
+        and the rejections table. Things reading from those table will need to check
+        whether the event was rejected.
+        """
         depth_updates = {}
         for event, context in events_and_contexts:
             # Remove the any existing cache entries for the event_ids
@@ -407,21 +413,11 @@ class EventsStore(SQLBaseStore):
                     event.room_id, event.internal_metadata.stream_ordering,
                 )
 
-            if not event.internal_metadata.is_outlier():
+            if not event.internal_metadata.is_outlier() and not context.rejected:
                 depth_updates[event.room_id] = max(
                     event.depth, depth_updates.get(event.room_id, event.depth)
                 )
 
-            if context.push_actions:
-                self._set_push_actions_for_event_and_users_txn(
-                    txn, event, context.push_actions
-                )
-
-        if event.type == EventTypes.Redaction and event.redacts is not None:
-            self._remove_push_actions_for_event_id_txn(
-                txn, event.room_id, event.redacts
-            )
-
         for room_id, depth in depth_updates.items():
             self._update_min_depth_for_room_txn(txn, room_id, depth)
 
@@ -431,14 +427,24 @@ class EventsStore(SQLBaseStore):
             ),
             [event.event_id for event, _ in events_and_contexts]
         )
+
         have_persisted = {
             event_id: outlier
             for event_id, outlier in txn.fetchall()
         }
 
+        # Remove the events that we've seen before.
         event_map = {}
         to_remove = set()
         for event, context in events_and_contexts:
+            if context.rejected:
+                # If the event is rejected then we don't care if the event
+                # was an outlier or not.
+                if event.event_id in have_persisted:
+                    # If we have already seen the event then ignore it.
+                    to_remove.add(event)
+                continue
+
             # Handle the case of the list including the same event multiple
             # times. The tricky thing here is when they differ by whether
             # they are an outlier.
@@ -463,6 +469,12 @@ class EventsStore(SQLBaseStore):
 
             outlier_persisted = have_persisted[event.event_id]
             if not event.internal_metadata.is_outlier() and outlier_persisted:
+                # We received a copy of an event that we had already stored as
+                # an outlier in the database. We now have some state at that
+                # so we need to update the state_groups table with that state.
+
+                # insert into the state_group, state_groups_state and
+                # event_to_state_groups tables.
                 self._store_mult_state_groups_txn(txn, ((event, context),))
 
                 metadata_json = encode_json(
@@ -478,6 +490,8 @@ class EventsStore(SQLBaseStore):
                     (metadata_json, event.event_id,)
                 )
 
+                # Add an entry to the ex_outlier_stream table to replicate the
+                # change in outlier status to our workers.
                 stream_order = event.internal_metadata.stream_ordering
                 state_group_id = context.state_group or context.new_state_group_id
                 self._simple_insert_txn(
@@ -499,6 +513,8 @@ class EventsStore(SQLBaseStore):
                     (False, event.event_id,)
                 )
 
+                # Update the event_backward_extremities table now that this
+                # event isn't an outlier any more.
                 self._update_extremeties(txn, [event])
 
         events_and_contexts = [
@@ -506,38 +522,12 @@ class EventsStore(SQLBaseStore):
         ]
 
         if not events_and_contexts:
+            # Make sure we don't pass an empty list to functions that expect to
+            # be storing at least one element.
             return
 
-        self._store_mult_state_groups_txn(txn, events_and_contexts)
-
-        self._handle_mult_prev_events(
-            txn,
-            events=[event for event, _ in events_and_contexts],
-        )
-
-        for event, _ in events_and_contexts:
-            if event.type == EventTypes.Name:
-                self._store_room_name_txn(txn, event)
-            elif event.type == EventTypes.Topic:
-                self._store_room_topic_txn(txn, event)
-            elif event.type == EventTypes.Message:
-                self._store_room_message_txn(txn, event)
-            elif event.type == EventTypes.Redaction:
-                self._store_redaction(txn, event)
-            elif event.type == EventTypes.RoomHistoryVisibility:
-                self._store_history_visibility_txn(txn, event)
-            elif event.type == EventTypes.GuestAccess:
-                self._store_guest_access_txn(txn, event)
-
-        self._store_room_members_txn(
-            txn,
-            [
-                event
-                for event, _ in events_and_contexts
-                if event.type == EventTypes.Member
-            ],
-            backfilled=backfilled,
-        )
+        # From this point onwards the events are only events that we haven't
+        # seen before.
 
         def event_dict(event):
             return {
@@ -591,10 +581,41 @@ class EventsStore(SQLBaseStore):
             ],
         )
 
-        if context.rejected:
-            self._store_rejections_txn(
-                txn, event.event_id, context.rejected
-            )
+        # Remove the rejected events from the list now that we've added them
+        # to the events table and the events_json table.
+        to_remove = set()
+        for event, context in events_and_contexts:
+            if context.rejected:
+                # Insert the event_id into the rejections table
+                self._store_rejections_txn(
+                    txn, event.event_id, context.rejected
+                )
+                to_remove.add(event)
+
+        events_and_contexts = [
+            ec for ec in events_and_contexts if ec[0] not in to_remove
+        ]
+
+        if not events_and_contexts:
+            # Make sure we don't pass an empty list to functions that expect to
+            # be storing at least one element.
+            return
+
+        # From this point onwards the events are only ones that weren't rejected.
+
+        for event, context in events_and_contexts:
+            # Insert all the push actions into the event_push_actions table.
+            if context.push_actions:
+                self._set_push_actions_for_event_and_users_txn(
+                    txn, event, context.push_actions
+                )
+
+            if event.type == EventTypes.Redaction and event.redacts is not None:
+                # Remove the entries in the event_push_actions table for the
+                # redacted event.
+                self._remove_push_actions_for_event_id_txn(
+                    txn, event.room_id, event.redacts
+                )
 
         self._simple_insert_many_txn(
             txn,
@@ -610,6 +631,49 @@ class EventsStore(SQLBaseStore):
             ],
         )
 
+        # Insert into the state_groups, state_groups_state, and
+        # event_to_state_groups tables.
+        self._store_mult_state_groups_txn(txn, events_and_contexts)
+
+        # Update the event_forward_extremities, event_backward_extremities and
+        # event_edges tables.
+        self._handle_mult_prev_events(
+            txn,
+            events=[event for event, _ in events_and_contexts],
+        )
+
+        for event, _ in events_and_contexts:
+            if event.type == EventTypes.Name:
+                # Insert into the room_names and event_search tables.
+                self._store_room_name_txn(txn, event)
+            elif event.type == EventTypes.Topic:
+                # Insert into the topics table and event_search table.
+                self._store_room_topic_txn(txn, event)
+            elif event.type == EventTypes.Message:
+                # Insert into the event_search table.
+                self._store_room_message_txn(txn, event)
+            elif event.type == EventTypes.Redaction:
+                # Insert into the redactions table.
+                self._store_redaction(txn, event)
+            elif event.type == EventTypes.RoomHistoryVisibility:
+                # Insert into the event_search table.
+                self._store_history_visibility_txn(txn, event)
+            elif event.type == EventTypes.GuestAccess:
+                # Insert into the event_search table.
+                self._store_guest_access_txn(txn, event)
+
+        # Insert into the room_memberships table.
+        self._store_room_members_txn(
+            txn,
+            [
+                event
+                for event, _ in events_and_contexts
+                if event.type == EventTypes.Member
+            ],
+            backfilled=backfilled,
+        )
+
+        # Insert event_reference_hashes table.
         self._store_event_reference_hashes_txn(
             txn, [event for event, _ in events_and_contexts]
         )
@@ -654,6 +718,7 @@ class EventsStore(SQLBaseStore):
             ],
         )
 
+        # Prefill the event cache
         self._add_to_cache(txn, events_and_contexts)
 
         if backfilled:
@@ -666,11 +731,6 @@ class EventsStore(SQLBaseStore):
                 # Outlier events shouldn't clobber the current state.
                 continue
 
-            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,)