Convert directory handler to async/await (#7727)

3 files changed, 33 insertions, 40 deletions

diff --git a/changelog.d/7727.misc b/changelog.d/7727.misc
new file mode 100644
index 0000000000..4d12d10fda
--- /dev/null
+++ b/changelog.d/7727.misc
@@ -0,0 +1 @@
+Convert directory handler to async/await.
diff --git a/synapse/handlers/directory.py b/synapse/handlers/directory.py
index f2f16b1e43..79a2df6201 100644
--- a/synapse/handlers/directory.py
+++ b/synapse/handlers/directory.py
@@ -17,8 +17,6 @@ import logging
 import string
 from typing import Iterable, List, Optional
 
-from twisted.internet import defer
-
 from synapse.api.constants import MAX_ALIAS_LENGTH, EventTypes
 from synapse.api.errors import (
     AuthError,
@@ -55,8 +53,7 @@ class DirectoryHandler(BaseHandler):
 
         self.spam_checker = hs.get_spam_checker()
 
-    @defer.inlineCallbacks
-    def _create_association(
+    async def _create_association(
         self,
         room_alias: RoomAlias,
         room_id: str,
@@ -76,13 +73,13 @@ class DirectoryHandler(BaseHandler):
         # TODO(erikj): Add transactions.
         # TODO(erikj): Check if there is a current association.
         if not servers:
-            users = yield self.state.get_current_users_in_room(room_id)
+            users = await self.state.get_current_users_in_room(room_id)
             servers = {get_domain_from_id(u) for u in users}
 
         if not servers:
             raise SynapseError(400, "Failed to get server list")
 
-        yield self.store.create_room_alias_association(
+        await self.store.create_room_alias_association(
             room_alias, room_id, servers, creator=creator
         )
 
@@ -93,7 +90,7 @@ class DirectoryHandler(BaseHandler):
         room_id: str,
         servers: Optional[List[str]] = None,
         check_membership: bool = True,
-    ):
+    ) -> None:
         """Attempt to create a new alias
 
         Args:
@@ -103,9 +100,6 @@ class DirectoryHandler(BaseHandler):
             servers: Iterable of servers that others servers should try and join via
             check_membership: Whether to check if the user is in the room
                 before the alias can be set (if the server's config requires it).
-
-        Returns:
-            Deferred
         """
 
         user_id = requester.user.to_string()
@@ -148,7 +142,7 @@ class DirectoryHandler(BaseHandler):
                 # per alias creation rule?
                 raise SynapseError(403, "Not allowed to create alias")
 
-            can_create = await self.can_modify_alias(room_alias, user_id=user_id)
+            can_create = self.can_modify_alias(room_alias, user_id=user_id)
             if not can_create:
                 raise AuthError(
                     400,
@@ -158,7 +152,9 @@ class DirectoryHandler(BaseHandler):
 
         await self._create_association(room_alias, room_id, servers, creator=user_id)
 
-    async def delete_association(self, requester: Requester, room_alias: RoomAlias):
+    async def delete_association(
+        self, requester: Requester, room_alias: RoomAlias
+    ) -> str:
         """Remove an alias from the directory
 
         (this is only meant for human users; AS users should call
@@ -169,7 +165,7 @@ class DirectoryHandler(BaseHandler):
             room_alias
 
         Returns:
-            Deferred[unicode]: room id that the alias used to point to
+            room id that the alias used to point to
 
         Raises:
             NotFoundError: if the alias doesn't exist
@@ -191,7 +187,7 @@ class DirectoryHandler(BaseHandler):
         if not can_delete:
             raise AuthError(403, "You don't have permission to delete the alias.")
 
-        can_delete = await self.can_modify_alias(room_alias, user_id=user_id)
+        can_delete = self.can_modify_alias(room_alias, user_id=user_id)
         if not can_delete:
             raise SynapseError(
                 400,
@@ -208,8 +204,7 @@ class DirectoryHandler(BaseHandler):
 
         return room_id
 
-    @defer.inlineCallbacks
-    def delete_appservice_association(
+    async def delete_appservice_association(
         self, service: ApplicationService, room_alias: RoomAlias
     ):
         if not service.is_interested_in_alias(room_alias.to_string()):
@@ -218,29 +213,27 @@ class DirectoryHandler(BaseHandler):
                 "This application service has not reserved this kind of alias",
                 errcode=Codes.EXCLUSIVE,
             )
-        yield self._delete_association(room_alias)
+        await self._delete_association(room_alias)
 
-    @defer.inlineCallbacks
-    def _delete_association(self, room_alias: RoomAlias):
+    async def _delete_association(self, room_alias: RoomAlias):
         if not self.hs.is_mine(room_alias):
             raise SynapseError(400, "Room alias must be local")
 
-        room_id = yield self.store.delete_room_alias(room_alias)
+        room_id = await self.store.delete_room_alias(room_alias)
 
         return room_id
 
-    @defer.inlineCallbacks
-    def get_association(self, room_alias: RoomAlias):
+    async def get_association(self, room_alias: RoomAlias):
         room_id = None
         if self.hs.is_mine(room_alias):
-            result = yield self.get_association_from_room_alias(room_alias)
+            result = await self.get_association_from_room_alias(room_alias)
 
             if result:
                 room_id = result.room_id
                 servers = result.servers
         else:
             try:
-                result = yield self.federation.make_query(
+                result = await self.federation.make_query(
                     destination=room_alias.domain,
                     query_type="directory",
                     args={"room_alias": room_alias.to_string()},
@@ -265,7 +258,7 @@ class DirectoryHandler(BaseHandler):
                 Codes.NOT_FOUND,
             )
 
-        users = yield self.state.get_current_users_in_room(room_id)
+        users = await self.state.get_current_users_in_room(room_id)
         extra_servers = {get_domain_from_id(u) for u in users}
         servers = set(extra_servers) | set(servers)
 
@@ -277,13 +270,12 @@ class DirectoryHandler(BaseHandler):
 
         return {"room_id": room_id, "servers": servers}
 
-    @defer.inlineCallbacks
-    def on_directory_query(self, args):
+    async def on_directory_query(self, args):
         room_alias = RoomAlias.from_string(args["room_alias"])
         if not self.hs.is_mine(room_alias):
             raise SynapseError(400, "Room Alias is not hosted on this homeserver")
 
-        result = yield self.get_association_from_room_alias(room_alias)
+        result = await self.get_association_from_room_alias(room_alias)
 
         if result is not None:
             return {"room_id": result.room_id, "servers": result.servers}
@@ -344,16 +336,15 @@ class DirectoryHandler(BaseHandler):
                 ratelimit=False,
             )
 
-    @defer.inlineCallbacks
-    def get_association_from_room_alias(self, room_alias: RoomAlias):
-        result = yield self.store.get_association_from_room_alias(room_alias)
+    async def get_association_from_room_alias(self, room_alias: RoomAlias):
+        result = await self.store.get_association_from_room_alias(room_alias)
         if not result:
             # Query AS to see if it exists
             as_handler = self.appservice_handler
-            result = yield as_handler.query_room_alias_exists(room_alias)
+            result = await as_handler.query_room_alias_exists(room_alias)
         return result
 
-    def can_modify_alias(self, alias: RoomAlias, user_id: Optional[str] = None):
+    def can_modify_alias(self, alias: RoomAlias, user_id: Optional[str] = None) -> bool:
         # Any application service "interested" in an alias they are regexing on
         # can modify the alias.
         # Users can only modify the alias if ALL the interested services have
@@ -366,12 +357,12 @@ class DirectoryHandler(BaseHandler):
         for service in interested_services:
             if user_id == service.sender:
                 # this user IS the app service so they can do whatever they like
-                return defer.succeed(True)
+                return True
             elif service.is_exclusive_alias(alias.to_string()):
                 # another service has an exclusive lock on this alias.
-                return defer.succeed(False)
+                return False
         # either no interested services, or no service with an exclusive lock
-        return defer.succeed(True)
+        return True
 
     async def _user_can_delete_alias(self, alias: RoomAlias, user_id: str):
         """Determine whether a user can delete an alias.
@@ -459,8 +450,7 @@ class DirectoryHandler(BaseHandler):
 
         await self.store.set_room_is_public(room_id, making_public)
 
-    @defer.inlineCallbacks
-    def edit_published_appservice_room_list(
+    async def edit_published_appservice_room_list(
         self, appservice_id: str, network_id: str, room_id: str, visibility: str
     ):
         """Add or remove a room from the appservice/network specific public
@@ -475,7 +465,7 @@ class DirectoryHandler(BaseHandler):
         if visibility not in ["public", "private"]:
             raise SynapseError(400, "Invalid visibility setting")
 
-        yield self.store.set_room_is_public_appservice(
+        await self.store.set_room_is_public_appservice(
             room_id, appservice_id, network_id, visibility == "public"
         )
 
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 200127d291..665ad19b5d 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -879,7 +879,9 @@ class EventCreationHandler(object):
         """
         room_alias = RoomAlias.from_string(room_alias_str)
         try:
-            mapping = yield directory_handler.get_association(room_alias)
+            mapping = yield defer.ensureDeferred(
+                directory_handler.get_association(room_alias)
+            )
         except SynapseError as e:
             # Turn M_NOT_FOUND errors into M_BAD_ALIAS errors.
             if e.errcode == Codes.NOT_FOUND: