Review comments

synapse/server.py

@@ -226,7 +226,6 @@ class HomeServer(object):
         self.admin_redaction_ratelimiter = Ratelimiter()
         self.registration_ratelimiter = Ratelimiter()
 
-        self.datastore = None
         self.datastores = None
 
         # Other kwargs are explicit dependencies
@@ -236,8 +235,8 @@ class HomeServer(object):
     def setup(self):
         logger.info("Setting up.")
         with self.get_db_conn() as conn:
-            self.datastore = self.DATASTORE_CLASS(conn, self)
-            self.datastores = DataStores(self.datastore, conn, self)
+            datastore = self.DATASTORE_CLASS(conn, self)
+            self.datastores = DataStores(datastore, conn, self)
             conn.commit()
         logger.info("Finished setting up.")
 

synapse/storage/__init__.py

@@ -29,7 +29,7 @@ stored in `synapse.storage.schema`.
 
 from synapse.storage.data_stores import DataStores
 from synapse.storage.data_stores.main import DataStore
-from synapse.storage.persist_events import EventsPersistenceStore
+from synapse.storage.persist_events import EventsPersistenceStorage
 
 __all__ = ["DataStores", "DataStore"]
 
@@ -44,7 +44,7 @@ class Storage(object):
         # interfaces.
         self.main = stores.main
 
-        self.persistence = EventsPersistenceStore(hs, stores)
+        self.persistence = EventsPersistenceStorage(hs, stores)
 
 
 def are_all_users_on_domain(txn, database_engine, domain):

synapse/storage/data_stores/main/events.py

@@ -146,7 +146,7 @@ class EventsStore(
 
     @_retry_on_integrity_error
     @defer.inlineCallbacks
-    def _persist_events(
+    def _persist_events_and_state_updates(
         self,
         events_and_contexts,
         current_state_for_room,
@@ -155,18 +155,27 @@ class EventsStore(
         backfilled=False,
         delete_existing=False,
     ):
-        """Persist events to db
+        """Persist a set of events alongside updates to the current state and
+        forward extremities tables.
 
         Args:
             events_and_contexts (list[(EventBase, EventContext)]):
-            backfilled (bool):
+            current_state_for_room (dict[str, dict]): Map from room_id to the
+                current state of the room based on forward extremities
+            state_delta_for_room (dict[str, tuple]): Map from room_id to tuple
+                of `(to_delete, to_insert)` where to_delete is a list
+                of type/state keys to remove from current state, and to_insert
+                is a map (type,key)->event_id giving the state delta in each
+                room.
+            new_forward_extremities (dict[str, list[str]]): Map from room_id
+                to list of event IDs that are the new forward extremities of
+                the room.
+            backfilled (bool)
             delete_existing (bool):
 
         Returns:
             Deferred: resolves when the events have been persisted
         """
-        if not events_and_contexts:
-            return
 
         # We want to calculate the stream orderings as late as possible, as
         # we only notify after all events with a lesser stream ordering have

synapse/storage/persist_events.py

@@ -171,7 +171,13 @@ class _EventPeristenceQueue(object):
             pass
 
 
-class EventsPersistenceStore(object):
+class EventsPersistenceStorage(object):
+    """High level interface for handling persisting newly received events.
+
+    Takes care of batching up events by room, and calculating the necessary
+    current state and forward extremity changes.
+    """
+
     def __init__(self, hs, stores: DataStores):
         # We ultimately want to split out the state store from the main store,
         # so we use separate variables here even though they point to the same
@@ -257,7 +263,8 @@ class EventsPersistenceStore(object):
     def _persist_events(
         self, events_and_contexts, backfilled=False, delete_existing=False
     ):
-        """Persist events to db
+        """Calculates the change to current state and forward extremities, and
+        persists the given events and with those updates.
 
         Args:
             events_and_contexts (list[(EventBase, EventContext)]):
@@ -399,7 +406,7 @@ class EventsPersistenceStore(object):
                         if current_state is not None:
                             current_state_for_room[room_id] = current_state
 
-            yield self.main_store._persist_events(
+            yield self.main_store._persist_events_and_state_updates(
                 chunk,
                 current_state_for_room=current_state_for_room,
                 state_delta_for_room=state_delta_for_room,

tests/crypto/test_keyring.py

@@ -178,7 +178,7 @@ class KeyringTestCase(unittest.HomeserverTestCase):
         kr = keyring.Keyring(self.hs)
 
         key1 = signedjson.key.generate_signing_key(1)
-        r = self.hs.datastore.store_server_verify_keys(
+        r = self.hs.get_datastore().store_server_verify_keys(
             "server9",
             time.time() * 1000,
             [("server9", get_key_id(key1), FetchKeyResult(get_verify_key(key1), 1000))],
@@ -209,7 +209,7 @@ class KeyringTestCase(unittest.HomeserverTestCase):
         )
 
         key1 = signedjson.key.generate_signing_key(1)
-        r = self.hs.datastore.store_server_verify_keys(
+        r = self.hs.get_datastore().store_server_verify_keys(
             "server9",
             time.time() * 1000,
             [("server9", get_key_id(key1), FetchKeyResult(get_verify_key(key1), None))],

tests/test_federation.py

@@ -36,7 +36,8 @@ class MessageAcceptTests(unittest.TestCase):
         # Figure out what the most recent event is
         most_recent = self.successResultOf(
             maybeDeferred(
-                self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+                self.homeserver.get_datastore().get_latest_event_ids_in_room,
+                self.room_id,
             )
         )[0]
 
@@ -75,7 +76,8 @@ class MessageAcceptTests(unittest.TestCase):
         self.assertEqual(
             self.successResultOf(
                 maybeDeferred(
-                    self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+                    self.homeserver.get_datastore().get_latest_event_ids_in_room,
+                    self.room_id,
                 )
             )[0],
             "$join:test.serv",
@@ -97,7 +99,8 @@ class MessageAcceptTests(unittest.TestCase):
         # Figure out what the most recent event is
         most_recent = self.successResultOf(
             maybeDeferred(
-                self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+                self.homeserver.get_datastore().get_latest_event_ids_in_room,
+                self.room_id,
             )
         )[0]
 
@@ -137,6 +140,6 @@ class MessageAcceptTests(unittest.TestCase):
 
         # Make sure the invalid event isn't there
         extrem = maybeDeferred(
-            self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+            self.homeserver.get_datastore().get_latest_event_ids_in_room, self.room_id
         )
         self.assertEqual(self.successResultOf(extrem)[0], "$join:test.serv")