Insert to-device messages into the new to-device part of AS txns

synapse/appservice/scheduler.py

@@ -71,6 +71,9 @@ MAX_PERSISTENT_EVENTS_PER_TRANSACTION = 100
 # Maximum number of ephemeral events to provide in an AS transaction.
 MAX_EPHEMERAL_EVENTS_PER_TRANSACTION = 100
 
+# Maximum number of to-device messages to provide in an AS transaction.
+MAX_TO_DEVICE_MESSAGES_PER_TRANSACTION = 100
+
 
 class ApplicationServiceScheduler:
     """Public facing API for this module. Does the required DI to tie the
@@ -102,6 +105,7 @@ class ApplicationServiceScheduler:
         appservice: ApplicationService,
         events: Optional[Iterable[EventBase]] = None,
         ephemeral: Optional[Iterable[JsonDict]] = None,
+        to_device_messages: Optional[Iterable[JsonDict]] = None,
     ) -> None:
         """
         Enqueue some data to be sent off to an application service.
@@ -109,6 +113,9 @@ class ApplicationServiceScheduler:
             appservice: The application service to create and send a transaction to.
             events: The persistent room events to send.
             ephemeral: The ephemeral events to send.
+            to_device_messages: The to-device messages to send. These differ from normal
+                to-device messages sent to clients, as they have 'to_device_id' and
+                'to_user_id' fields.
         """
         # We purposefully allow this method to run with empty events/ephemeral
         # iterables, so that callers do not need to check iterable size themselves.
@@ -119,6 +126,10 @@ class ApplicationServiceScheduler:
             self.queuer.queued_events.setdefault(appservice.id, []).extend(events)
         if ephemeral:
             self.queuer.queued_ephemeral.setdefault(appservice.id, []).extend(ephemeral)
+        if to_device_messages:
+            self.queuer.queued_to_device_messages.setdefault(appservice.id, []).extend(
+                to_device_messages
+            )
 
         # Kick off a new application service transaction
         self.queuer.start_background_request(appservice)
@@ -137,7 +148,8 @@ class _ServiceQueuer:
         self.queued_events: Dict[str, List[EventBase]] = {}
         # dict of {service_id: [event_json]}
         self.queued_ephemeral: Dict[str, List[JsonDict]] = {}
-        self.queued_ephemeral: Dict[str, List[JsonDict]] = {}
+        # dict of {service_id: [to_device_message_json]}
+        self.queued_to_device_messages: Dict[str, List[JsonDict]] = {}
 
         # the appservices which currently have a transaction in flight
         self.requests_in_flight: Set[str] = set()
@@ -169,11 +181,21 @@ class _ServiceQueuer:
                 ephemeral = all_events_ephemeral[:MAX_EPHEMERAL_EVENTS_PER_TRANSACTION]
                 del all_events_ephemeral[:MAX_EPHEMERAL_EVENTS_PER_TRANSACTION]
 
-                if not events and not ephemeral:
+                all_to_device_messages = self.queued_to_device_messages.get(
+                    service.id, []
+                )
+                to_device_messages_to_send = all_to_device_messages[
+                    :MAX_TO_DEVICE_MESSAGES_PER_TRANSACTION
+                ]
+                del all_to_device_messages[:MAX_TO_DEVICE_MESSAGES_PER_TRANSACTION]
+
+                if not events and not ephemeral and not to_device_messages_to_send:
                     return
 
                 try:
-                    await self.txn_ctrl.send(service, events, ephemeral)
+                    await self.txn_ctrl.send(
+                        service, events, ephemeral, to_device_messages_to_send
+                    )
                 except Exception:
                     logger.exception("AS request failed")
         finally:
@@ -205,6 +227,7 @@ class _TransactionController:
         service: ApplicationService,
         events: List[EventBase],
         ephemeral: Optional[List[JsonDict]] = None,
+        to_device_messages: Optional[List[JsonDict]] = None,
     ) -> None:
         """
         Create a transaction with the given data and send to the provided
@@ -214,10 +237,14 @@ class _TransactionController:
             service: The application service to send the transaction to.
             events: The persistent events to include in the transaction.
             ephemeral: The ephemeral events to include in the transaction.
+            to_device_messages: The to-device messages to include in the transaction.
         """
         try:
             txn = await self.store.create_appservice_txn(
-                service=service, events=events, ephemeral=ephemeral or []
+                service=service,
+                events=events,
+                ephemeral=ephemeral or [],
+                to_device_messages=to_device_messages or [],
             )
             service_is_up = await self._is_service_up(service)
             if service_is_up:

synapse/handlers/appservice.py

@@ -327,10 +327,8 @@ class ApplicationServicesHandler:
                         to_device_messages = await self._get_to_device_messages(
                             service, new_token, users
                         )
-                        # REVIEW: In a subsequent commit, we'll move this to a to-device-specific
-                        #  key in the AS transaction.
                         self.scheduler.enqueue_for_appservice(
-                            service, ephemeral=to_device_messages
+                            service, to_device_messages=to_device_messages
                         )
 
                         # Persist the latest handled stream token for this appservice