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).

5 files changed, 22 insertions, 20 deletions

diff --git a/synapse/handlers/events.py b/synapse/handlers/events.py

index 0875b74ea8..539b4fc32e 100644
--- a/synapse/handlers/events.py
+++ b/synapse/handlers/events.py
@@ -133,8 +133,8 @@ class EventStreamHandler(BaseHandler):
 
             chunk = {
                 "chunk": chunks,
-                "start": tokens[0].to_string(),
-                "end": tokens[1].to_string(),
+                "start": await tokens[0].to_string(self.store),
+                "end": await tokens[1].to_string(self.store),
             }
 
             return chunk
diff --git a/synapse/handlers/initial_sync.py b/synapse/handlers/initial_sync.py

index 43f15435de..39a85801c1 100644
--- a/synapse/handlers/initial_sync.py
+++ b/synapse/handlers/initial_sync.py
@@ -203,8 +203,8 @@ class InitialSyncHandler(BaseHandler):
                             messages, time_now=time_now, as_client_event=as_client_event
                         )
                     ),
-                    "start": start_token.to_string(),
-                    "end": end_token.to_string(),
+                    "start": await start_token.to_string(self.store),
+                    "end": await end_token.to_string(self.store),
                 }
 
                 d["state"] = await self._event_serializer.serialize_events(
@@ -249,7 +249,7 @@ class InitialSyncHandler(BaseHandler):
             ],
             "account_data": account_data_events,
             "receipts": receipt,
-            "end": now_token.to_string(),
+            "end": await now_token.to_string(self.store),
         }
 
         return ret
@@ -348,8 +348,8 @@ class InitialSyncHandler(BaseHandler):
                 "chunk": (
                     await self._event_serializer.serialize_events(messages, time_now)
                 ),
-                "start": start_token.to_string(),
-                "end": end_token.to_string(),
+                "start": await start_token.to_string(self.store),
+                "end": await end_token.to_string(self.store),
             },
             "state": (
                 await self._event_serializer.serialize_events(
@@ -447,8 +447,8 @@ class InitialSyncHandler(BaseHandler):
                 "chunk": (
                     await self._event_serializer.serialize_events(messages, time_now)
                 ),
-                "start": start_token.to_string(),
-                "end": end_token.to_string(),
+                "start": await start_token.to_string(self.store),
+                "end": await end_token.to_string(self.store),
             },
             "state": state,
             "presence": presence,
diff --git a/synapse/handlers/pagination.py b/synapse/handlers/pagination.py

index d6779a4b44..2c2a633938 100644
--- a/synapse/handlers/pagination.py
+++ b/synapse/handlers/pagination.py
@@ -413,8 +413,8 @@ class PaginationHandler:
         if not events:
             return {
                 "chunk": [],
-                "start": from_token.to_string(),
-                "end": next_token.to_string(),
+                "start": await from_token.to_string(self.store),
+                "end": await next_token.to_string(self.store),
             }
 
         state = None
@@ -442,8 +442,8 @@ class PaginationHandler:
                     events, time_now, as_client_event=as_client_event
                 )
             ),
-            "start": from_token.to_string(),
-            "end": next_token.to_string(),
+            "start": await from_token.to_string(self.store),
+            "end": await next_token.to_string(self.store),
         }
 
         if state:
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py

index 836b3f381a..d5f7c78edf 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -1077,11 +1077,13 @@ class RoomContextHandler:
         # the token, which we replace.
         token = StreamToken.START
 
-        results["start"] = token.copy_and_replace(
+        results["start"] = await token.copy_and_replace(
             "room_key", results["start"]
-        ).to_string()
+        ).to_string(self.store)
 
-        results["end"] = token.copy_and_replace("room_key", results["end"]).to_string()
+        results["end"] = await token.copy_and_replace(
+            "room_key", results["end"]
+        ).to_string(self.store)
 
         return results
 
diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py

index 6a76c20d79..e9402e6e2e 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -362,13 +362,13 @@ class SearchHandler(BaseHandler):
                     self.storage, user.to_string(), res["events_after"]
                 )
 
-                res["start"] = now_token.copy_and_replace(
+                res["start"] = await now_token.copy_and_replace(
                     "room_key", res["start"]
-                ).to_string()
+                ).to_string(self.store)
 
-                res["end"] = now_token.copy_and_replace(
+                res["end"] = await now_token.copy_and_replace(
                     "room_key", res["end"]
-                ).to_string()
+                ).to_string(self.store)
 
                 if include_profile:
                     senders = {