Refactor getting replication updates from database. (#7636)

The aim here is to make it easier to reason about when streams are limited and when they're not, by moving the logic into the database functions themselves. This should mean we can kill of `db_query_to_update_function` function.

1 files changed, 8 insertions, 21 deletions

diff --git a/synapse/replication/tcp/streams/_base.py b/synapse/replication/tcp/streams/_base.py

index 4acefc8a96..f196eff072 100644
--- a/synapse/replication/tcp/streams/_base.py
+++ b/synapse/replication/tcp/streams/_base.py
@@ -264,7 +264,7 @@ class BackfillStream(Stream):
         super().__init__(
             hs.get_instance_name(),
             current_token_without_instance(store.get_current_backfill_token),
-            db_query_to_update_function(store.get_all_new_backfill_event_rows),
+            store.get_all_new_backfill_event_rows,
         )
 
 
@@ -291,9 +291,7 @@ class PresenceStream(Stream):
         if hs.config.worker_app is None:
             # on the master, query the presence handler
             presence_handler = hs.get_presence_handler()
-            update_function = db_query_to_update_function(
-                presence_handler.get_all_presence_updates
-            )
+            update_function = presence_handler.get_all_presence_updates
         else:
             # Query master process
             update_function = make_http_update_function(hs, self.NAME)
@@ -318,9 +316,7 @@ class TypingStream(Stream):
 
         if hs.config.worker_app is None:
             # on the master, query the typing handler
-            update_function = db_query_to_update_function(
-                typing_handler.get_all_typing_updates
-            )
+            update_function = typing_handler.get_all_typing_updates
         else:
             # Query master process
             update_function = make_http_update_function(hs, self.NAME)
@@ -352,7 +348,7 @@ class ReceiptsStream(Stream):
         super().__init__(
             hs.get_instance_name(),
             current_token_without_instance(store.get_max_receipt_stream_id),
-            db_query_to_update_function(store.get_all_updated_receipts),
+            store.get_all_updated_receipts,
         )
 
 
@@ -367,26 +363,17 @@ class PushRulesStream(Stream):
 
     def __init__(self, hs):
         self.store = hs.get_datastore()
+
         super(PushRulesStream, self).__init__(
-            hs.get_instance_name(), self._current_token, self._update_function
+            hs.get_instance_name(),
+            self._current_token,
+            self.store.get_all_push_rule_updates,
         )
 
     def _current_token(self, instance_name: str) -> int:
         push_rules_token, _ = self.store.get_push_rules_stream_token()
         return push_rules_token
 
-    async def _update_function(
-        self, instance_name: str, from_token: Token, to_token: Token, limit: int
-    ):
-        rows = await self.store.get_all_push_rule_updates(from_token, to_token, limit)
-
-        limited = False
-        if len(rows) == limit:
-            to_token = rows[-1][0]
-            limited = True
-
-        return [(row[0], (row[2],)) for row in rows], to_token, limited
-
 
 class PushersStream(Stream):
     """A user has added/changed/removed a pusher