Move get_state methods into FederationHandler (#6503)

* commit 'be294d6fd':
  Move get_state methods into FederationHandler (#6503)

synapse/federation/federation_client.py

@@ -39,7 +39,7 @@
 from synapse.federation.federation_base import FederationBase, event_from_pdu_json
 from synapse.logging.context import make_deferred_yieldable
 from synapse.logging.utils import log_function
-from synapse.util import batch_iter, unwrapFirstError
+from synapse.util import unwrapFirstError
 from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.util.retryutils import NotRetryingDestination
 
@@ -327,74 +327,7 @@ def get_room_state_ids(self, destination: str, room_id: str, event_id: str):
         ):
             raise Exception("invalid response from /state_ids")
 
-        desired_events = set(state_event_ids + auth_event_ids)
-        event_map = yield self.get_events_from_store_or_dest(
-            destination, room_id, desired_events
-        )
-
-        failed_to_fetch = desired_events - event_map.keys()
-        if failed_to_fetch:
-            logger.warning(
-                "Failed to fetch missing state/auth events for %s: %s",
-                room_id,
-                failed_to_fetch,
-            )
-
-        pdus = [event_map[e_id] for e_id in state_event_ids if e_id in event_map]
-        auth_chain = [event_map[e_id] for e_id in auth_event_ids if e_id in event_map]
-
-        auth_chain.sort(key=lambda e: e.depth)
-
-        return pdus, auth_chain
-
-    @defer.inlineCallbacks
-    def get_events_from_store_or_dest(self, destination, room_id, event_ids):
-        """Fetch events from a remote destination, checking if we already have them.
-
-        Args:
-            destination (str)
-            room_id (str)
-            event_ids (Iterable[str])
-
-        Returns:
-            Deferred[dict[str, EventBase]]: A deferred resolving to a map
-            from event_id to event
-        """
-        fetched_events = yield self.store.get_events(event_ids, allow_rejected=True)
-
-        missing_events = set(event_ids) - fetched_events.keys()
-
-        if not missing_events:
-            return fetched_events
-
-        logger.debug(
-            "Fetching unknown state/auth events %s for room %s",
-            missing_events,
-            event_ids,
-        )
-
-        room_version = yield self.store.get_room_version(room_id)
-
-        # XXX 20 requests at once? really?
-        for batch in batch_iter(missing_events, 20):
-            deferreds = [
-                run_in_background(
-                    self.get_pdu,
-                    destinations=[destination],
-                    event_id=e_id,
-                    room_version=room_version,
-                )
-                for e_id in batch
-            ]
-
-            res = yield make_deferred_yieldable(
-                defer.DeferredList(deferreds, consumeErrors=True)
-            )
-            for success, result in res:
-                if success and result:
-                    fetched_events[result.event_id] = result
-
-        return fetched_events
+        return state_event_ids, auth_event_ids
 
     @defer.inlineCallbacks
     @log_function