Handle inbound events from federation asynchronously (#10272)

Fixes #9490

This will break a couple of SyTest that are expecting failures to be added to the response of a federation /send, which obviously doesn't happen now that things are asynchronous.

Two drawbacks:

    Currently there is no logic to handle any events left in the staging area after restart, and so they'll only be handled on the next incoming event in that room. That can be fixed separately.
    We now only process one event per room at a time. This can be fixed up further down the line.

1 files changed, 32 insertions, 0 deletions

diff --git a/synapse/storage/schema/main/delta/59/16federation_inbound_staging.sql b/synapse/storage/schema/main/delta/59/16federation_inbound_staging.sql
new file mode 100644
index 0000000000..43bc5c025f
--- /dev/null
+++ b/synapse/storage/schema/main/delta/59/16federation_inbound_staging.sql
@@ -0,0 +1,32 @@
+/* Copyright 2021 The Matrix.org Foundation C.I.C
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+-- A staging area for newly received events over federation.
+--
+-- Note we may store the same event multiple times if it comes from different
+-- servers; this is to handle the case if we get a redacted and non-redacted
+-- versions of the event.
+CREATE TABLE federation_inbound_events_staging (
+    origin TEXT NOT NULL,
+    room_id TEXT NOT NULL,
+    event_id TEXT NOT NULL,
+    received_ts BIGINT NOT NULL,
+    event_json TEXT NOT NULL,
+    internal_metadata TEXT NOT NULL
+);
+
+CREATE INDEX federation_inbound_events_staging_room ON federation_inbound_events_staging(room_id, received_ts);
+CREATE UNIQUE INDEX federation_inbound_events_staging_instance_event ON federation_inbound_events_staging(origin, event_id);