Convert streams to async.

changelog.d/8014.misc

@@ -0,0 +1 @@
+Convert various parts of the codebase to async/await.

synapse/streams/events.py

@@ -15,8 +15,6 @@
 
 from typing import Any, Dict
 
-from twisted.internet import defer
-
 from synapse.handlers.account_data import AccountDataEventSource
 from synapse.handlers.presence import PresenceEventSource
 from synapse.handlers.receipts import ReceiptEventSource
@@ -40,39 +38,37 @@ def __init__(self, hs):
         }  # type: Dict[str, Any]
         self.store = hs.get_datastore()
 
-    @defer.inlineCallbacks
-    def get_current_token(self):
+    async def get_current_token(self) -> StreamToken:
         push_rules_key, _ = self.store.get_push_rules_stream_token()
         to_device_key = self.store.get_to_device_stream_token()
         device_list_key = self.store.get_device_stream_token()
         groups_key = self.store.get_group_stream_token()
 
         token = StreamToken(
-            room_key=(yield self.sources["room"].get_current_key()),
-            presence_key=(yield self.sources["presence"].get_current_key()),
-            typing_key=(yield self.sources["typing"].get_current_key()),
-            receipt_key=(yield self.sources["receipt"].get_current_key()),
-            account_data_key=(yield self.sources["account_data"].get_current_key()),
+            room_key=await self.sources["room"].get_current_key(),
+            presence_key=self.sources["presence"].get_current_key(),
+            typing_key=self.sources["typing"].get_current_key(),
+            receipt_key=self.sources["receipt"].get_current_key(),
+            account_data_key=self.sources["account_data"].get_current_key(),
             push_rules_key=push_rules_key,
             to_device_key=to_device_key,
             device_list_key=device_list_key,
             groups_key=groups_key,
         )
         return token
 
-    @defer.inlineCallbacks
-    def get_current_token_for_pagination(self):
+    async def get_current_token_for_pagination(self) -> StreamToken:
         """Get the current token for a given room to be used to paginate
         events.
 
         The returned token does not have the current values for fields other
         than `room`, since they are not used during pagination.
 
         Returns:
-            Deferred[StreamToken]
+            The current token for pagination.
         """
         token = StreamToken(
-            room_key=(yield self.sources["room"].get_current_key()),
+            room_key=await self.sources["room"].get_current_key(),
             presence_key=0,
             typing_key=0,
             receipt_key=0,