Make token serializing/deserializing async (#8427)

The idea is that in future tokens will encode a mapping of instance to position. However, we don't want to include the full instance name in the string representation, so instead we'll have a mapping between instance name and an immutable integer ID in the DB that we can use instead. We'll then do the lookup when we serialize/deserialize the token (we could alternatively pass around an `Instance` type that includes both the name and ID, but that turns out to be a lot more invasive).

2 files changed, 28 insertions, 11 deletions

diff --git a/tests/rest/client/v1/test_rooms.py b/tests/rest/client/v1/test_rooms.py
index a3287011e9..0d809d25d5 100644
--- a/tests/rest/client/v1/test_rooms.py
+++ b/tests/rest/client/v1/test_rooms.py
@@ -902,16 +902,18 @@ class RoomMessageListTestCase(RoomBase):
 
         # Send a first message in the room, which will be removed by the purge.
         first_event_id = self.helper.send(self.room_id, "message 1")["event_id"]
-        first_token = str(
-            self.get_success(store.get_topological_token_for_event(first_event_id))
+        first_token = self.get_success(
+            store.get_topological_token_for_event(first_event_id)
         )
+        first_token_str = self.get_success(first_token.to_string(store))
 
         # Send a second message in the room, which won't be removed, and which we'll
         # use as the marker to purge events before.
         second_event_id = self.helper.send(self.room_id, "message 2")["event_id"]
-        second_token = str(
-            self.get_success(store.get_topological_token_for_event(second_event_id))
+        second_token = self.get_success(
+            store.get_topological_token_for_event(second_event_id)
         )
+        second_token_str = self.get_success(second_token.to_string(store))
 
         # Send a third event in the room to ensure we don't fall under any edge case
         # due to our marker being the latest forward extremity in the room.
@@ -921,7 +923,11 @@ class RoomMessageListTestCase(RoomBase):
         request, channel = self.make_request(
             "GET",
             "/rooms/%s/messages?access_token=x&from=%s&dir=b&filter=%s"
-            % (self.room_id, second_token, json.dumps({"types": [EventTypes.Message]})),
+            % (
+                self.room_id,
+                second_token_str,
+                json.dumps({"types": [EventTypes.Message]}),
+            ),
         )
         self.render(request)
         self.assertEqual(channel.code, 200, channel.json_body)
@@ -936,7 +942,7 @@ class RoomMessageListTestCase(RoomBase):
             pagination_handler._purge_history(
                 purge_id=purge_id,
                 room_id=self.room_id,
-                token=second_token,
+                token=second_token_str,
                 delete_local_events=True,
             )
         )
@@ -946,7 +952,11 @@ class RoomMessageListTestCase(RoomBase):
         request, channel = self.make_request(
             "GET",
             "/rooms/%s/messages?access_token=x&from=%s&dir=b&filter=%s"
-            % (self.room_id, second_token, json.dumps({"types": [EventTypes.Message]})),
+            % (
+                self.room_id,
+                second_token_str,
+                json.dumps({"types": [EventTypes.Message]}),
+            ),
         )
         self.render(request)
         self.assertEqual(channel.code, 200, channel.json_body)
@@ -960,7 +970,11 @@ class RoomMessageListTestCase(RoomBase):
         request, channel = self.make_request(
             "GET",
             "/rooms/%s/messages?access_token=x&from=%s&dir=b&filter=%s"
-            % (self.room_id, first_token, json.dumps({"types": [EventTypes.Message]})),
+            % (
+                self.room_id,
+                first_token_str,
+                json.dumps({"types": [EventTypes.Message]}),
+            ),
         )
         self.render(request)
         self.assertEqual(channel.code, 200, channel.json_body)
diff --git a/tests/storage/test_purge.py b/tests/storage/test_purge.py
index 723cd28933..cc1f3c53c5 100644
--- a/tests/storage/test_purge.py
+++ b/tests/storage/test_purge.py
@@ -47,12 +47,15 @@ class PurgeTests(HomeserverTestCase):
         storage = self.hs.get_storage()
 
         # Get the topological token
-        event = str(
-            self.get_success(store.get_topological_token_for_event(last["event_id"]))
+        token = self.get_success(
+            store.get_topological_token_for_event(last["event_id"])
         )
+        token_str = self.get_success(token.to_string(self.hs.get_datastore()))
 
         # Purge everything before this topological token
-        self.get_success(storage.purge_events.purge_history(self.room_id, event, True))
+        self.get_success(
+            storage.purge_events.purge_history(self.room_id, token_str, True)
+        )
 
         # 1-3 should fail and last will succeed, meaning that 1-3 are deleted
         # and last is not.