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authorErik Johnston <erik@matrix.org>2019-12-13 10:55:33 +0000
committerErik Johnston <erik@matrix.org>2019-12-13 10:55:33 +0000
commitbee1982d177234d92d06c352a303653eee9c1e98 (patch)
treea81fb4a2dc8bd176282ef33a26d04a9d52d4e3fd /synapse/handlers/federation.py
parentUpdate workers.md to make media_repository work (again) (#6519) (diff)
parentMore rewording of changelog. (diff)
downloadsynapse-bee1982d177234d92d06c352a303653eee9c1e98.tar.xz
Merge tag 'v1.7.0'
Synapse 1.7.0 (2019-12-13)
==========================

This release changes the default settings so that only local authenticated users can query the server's room directory. See the [upgrade notes](UPGRADE.rst#upgrading-to-v170) for details.

Support for SQLite versions before 3.11 is now deprecated. A future release will refuse to start if used with an SQLite version before 3.11.

Administrators are reminded that SQLite should not be used for production instances. Instructions for migrating to Postgres are available [here](docs/postgres.md). A future release of synapse will, by default, disable federation for servers using SQLite.

No significant changes since 1.7.0rc2.

Synapse 1.7.0rc2 (2019-12-11)
=============================

Bugfixes
--------

- Fix incorrect error message for invalid requests when setting user's avatar URL. ([\#6497](https://github.com/matrix-org/synapse/issues/6497))
- Fix support for SQLite 3.7. ([\#6499](https://github.com/matrix-org/synapse/issues/6499))
- Fix regression where sending email push would not work when using a pusher worker. ([\#6507](https://github.com/matrix-org/synapse/issues/6507), [\#6509](https://github.com/matrix-org/synapse/issues/6509))

Synapse 1.7.0rc1 (2019-12-09)
=============================

Features
--------

- Implement per-room message retention policies. ([\#5815](https://github.com/matrix-org/synapse/issues/5815), [\#6436](https://github.com/matrix-org/synapse/issues/6436))
- Add etag and count fields to key backup endpoints to help clients guess if there are new keys. ([\#5858](https://github.com/matrix-org/synapse/issues/5858))
- Add `/admin/v2/users` endpoint with pagination. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#5925](https://github.com/matrix-org/synapse/issues/5925))
- Require User-Interactive Authentication for `/account/3pid/add`, meaning the user's password will be required to add a third-party ID to their account. ([\#6119](https://github.com/matrix-org/synapse/issues/6119))
- Implement the `/_matrix/federation/unstable/net.atleastfornow/state/<context>` API as drafted in MSC2314. ([\#6176](https://github.com/matrix-org/synapse/issues/6176))
- Configure privacy-preserving settings by default for the room directory. ([\#6355](https://github.com/matrix-org/synapse/issues/6355))
- Add ephemeral messages support by partially implementing [MSC2228](https://github.com/matrix-org/matrix-doc/pull/2228). ([\#6409](https://github.com/matrix-org/synapse/issues/6409))
- Add support for [MSC 2367](https://github.com/matrix-org/matrix-doc/pull/2367), which allows specifying a reason on all membership events. ([\#6434](https://github.com/matrix-org/synapse/issues/6434))

Bugfixes
--------

- Transfer non-standard power levels on room upgrade. ([\#6237](https://github.com/matrix-org/synapse/issues/6237))
- Fix error from the Pillow library when uploading RGBA images. ([\#6241](https://github.com/matrix-org/synapse/issues/6241))
- Correctly apply the event filter to the `state`, `events_before` and `events_after` fields in the response to `/context` requests. ([\#6329](https://github.com/matrix-org/synapse/issues/6329))
- Fix caching devices for remote users when using workers, so that we don't attempt to refetch (and potentially fail) each time a user requests devices. ([\#6332](https://github.com/matrix-org/synapse/issues/6332))
- Prevent account data syncs getting lost across TCP replication. ([\#6333](https://github.com/matrix-org/synapse/issues/6333))
- Fix bug: TypeError in `register_user()` while using LDAP auth module. ([\#6406](https://github.com/matrix-org/synapse/issues/6406))
- Fix an intermittent exception when handling read-receipts. ([\#6408](https://github.com/matrix-org/synapse/issues/6408))
- Fix broken guest registration when there are existing blocks of numeric user IDs. ([\#6420](https://github.com/matrix-org/synapse/issues/6420))
- Fix startup error when http proxy is defined. ([\#6421](https://github.com/matrix-org/synapse/issues/6421))
- Fix error when using synapse_port_db on a vanilla synapse db. ([\#6449](https://github.com/matrix-org/synapse/issues/6449))
- Fix uploading multiple cross signing signatures for the same user. ([\#6451](https://github.com/matrix-org/synapse/issues/6451))
- Fix bug which lead to exceptions being thrown in a loop when a cross-signed device is deleted. ([\#6462](https://github.com/matrix-org/synapse/issues/6462))
- Fix `synapse_port_db` not exiting with a 0 code if something went wrong during the port process. ([\#6470](https://github.com/matrix-org/synapse/issues/6470))
- Improve sanity-checking when receiving events over federation. ([\#6472](https://github.com/matrix-org/synapse/issues/6472))
- Fix inaccurate per-block Prometheus metrics. ([\#6491](https://github.com/matrix-org/synapse/issues/6491))
- Fix small performance regression for sending invites. ([\#6493](https://github.com/matrix-org/synapse/issues/6493))
- Back out cross-signing code added in Synapse 1.5.0, which caused a performance regression. ([\#6494](https://github.com/matrix-org/synapse/issues/6494))

Improved Documentation
----------------------

- Update documentation and variables in user contributed systemd reference file. ([\#6369](https://github.com/matrix-org/synapse/issues/6369), [\#6490](https://github.com/matrix-org/synapse/issues/6490))
- Fix link in the user directory documentation. ([\#6388](https://github.com/matrix-org/synapse/issues/6388))
- Add build instructions to the docker readme. ([\#6390](https://github.com/matrix-org/synapse/issues/6390))
- Switch Ubuntu package install recommendation to use python3 packages in INSTALL.md. ([\#6443](https://github.com/matrix-org/synapse/issues/6443))
- Write some docs for the quarantine_media api. ([\#6458](https://github.com/matrix-org/synapse/issues/6458))
- Convert CONTRIBUTING.rst to markdown (among other small fixes). ([\#6461](https://github.com/matrix-org/synapse/issues/6461))

Deprecations and Removals
-------------------------

- Remove admin/v1/users_paginate endpoint. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#5925](https://github.com/matrix-org/synapse/issues/5925))
- Remove fallback for federation with old servers which lack the /federation/v1/state_ids API. ([\#6488](https://github.com/matrix-org/synapse/issues/6488))

Internal Changes
----------------

- Add benchmarks for structured logging and improve output performance. ([\#6266](https://github.com/matrix-org/synapse/issues/6266))
- Improve the performance of outputting structured logging. ([\#6322](https://github.com/matrix-org/synapse/issues/6322))
- Refactor some code in the event authentication path for clarity. ([\#6343](https://github.com/matrix-org/synapse/issues/6343), [\#6468](https://github.com/matrix-org/synapse/issues/6468), [\#6480](https://github.com/matrix-org/synapse/issues/6480))
- Clean up some unnecessary quotation marks around the codebase. ([\#6362](https://github.com/matrix-org/synapse/issues/6362))
- Complain on startup instead of 500'ing during runtime when `public_baseurl` isn't set when necessary. ([\#6379](https://github.com/matrix-org/synapse/issues/6379))
- Add a test scenario to make sure room history purges don't break `/messages` in the future. ([\#6392](https://github.com/matrix-org/synapse/issues/6392))
- Clarifications for the email configuration settings. ([\#6423](https://github.com/matrix-org/synapse/issues/6423))
- Add more tests to the blacklist when running in worker mode. ([\#6429](https://github.com/matrix-org/synapse/issues/6429))
- Refactor data store layer to support multiple databases in the future. ([\#6454](https://github.com/matrix-org/synapse/issues/6454), [\#6464](https://github.com/matrix-org/synapse/issues/6464), [\#6469](https://github.com/matrix-org/synapse/issues/6469), [\#6487](https://github.com/matrix-org/synapse/issues/6487))
- Port synapse.rest.client.v1 to async/await. ([\#6482](https://github.com/matrix-org/synapse/issues/6482))
- Port synapse.rest.client.v2_alpha to async/await. ([\#6483](https://github.com/matrix-org/synapse/issues/6483))
- Port SyncHandler to async/await. ([\#6484](https://github.com/matrix-org/synapse/issues/6484))
Diffstat (limited to 'synapse/handlers/federation.py')
-rw-r--r--synapse/handlers/federation.py238
1 files changed, 144 insertions, 94 deletions
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 0e904f2da0..bc26921768 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -19,11 +19,13 @@
 
 import itertools
 import logging
+from typing import Dict, Iterable, Optional, Sequence, Tuple
 
 import six
 from six import iteritems, itervalues
 from six.moves import http_client, zip
 
+import attr
 from signedjson.key import decode_verify_key_bytes
 from signedjson.sign import verify_signed_json
 from unpaddedbase64 import decode_base64
@@ -45,6 +47,7 @@ from synapse.api.errors import (
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersions
 from synapse.crypto.event_signing import compute_event_signature
 from synapse.event_auth import auth_types_for_event
+from synapse.events import EventBase
 from synapse.events.snapshot import EventContext
 from synapse.events.validator import EventValidator
 from synapse.logging.context import (
@@ -72,6 +75,23 @@ from ._base import BaseHandler
 logger = logging.getLogger(__name__)
 
 
+@attr.s
+class _NewEventInfo:
+    """Holds information about a received event, ready for passing to _handle_new_events
+
+    Attributes:
+        event: the received event
+
+        state: the state at that event
+
+        auth_events: the auth_event map for that event
+    """
+
+    event = attr.ib(type=EventBase)
+    state = attr.ib(type=Optional[Sequence[EventBase]], default=None)
+    auth_events = attr.ib(type=Optional[Dict[Tuple[str, str], EventBase]], default=None)
+
+
 def shortstr(iterable, maxitems=5):
     """If iterable has maxitems or fewer, return the stringification of a list
     containing those items.
@@ -121,6 +141,7 @@ class FederationHandler(BaseHandler):
         self.pusher_pool = hs.get_pusherpool()
         self.spam_checker = hs.get_spam_checker()
         self.event_creation_handler = hs.get_event_creation_handler()
+        self._message_handler = hs.get_message_handler()
         self._server_notices_mxid = hs.config.server_notices_mxid
         self.config = hs.config
         self.http_client = hs.get_simple_http_client()
@@ -141,6 +162,8 @@ class FederationHandler(BaseHandler):
 
         self.third_party_event_rules = hs.get_third_party_event_rules()
 
+        self._ephemeral_messages_enabled = hs.config.enable_ephemeral_messages
+
     @defer.inlineCallbacks
     def on_receive_pdu(self, origin, pdu, sent_to_us_directly=False):
         """ Process a PDU received via a federation /send/ transaction, or
@@ -594,14 +617,14 @@ class FederationHandler(BaseHandler):
                     for e in auth_chain
                     if e.event_id in auth_ids or e.type == EventTypes.Create
                 }
-                event_infos.append({"event": e, "auth_events": auth})
+                event_infos.append(_NewEventInfo(event=e, auth_events=auth))
                 seen_ids.add(e.event_id)
 
             logger.info(
                 "[%s %s] persisting newly-received auth/state events %s",
                 room_id,
                 event_id,
-                [e["event"].event_id for e in event_infos],
+                [e.event.event_id for e in event_infos],
             )
             yield self._handle_new_events(origin, event_infos)
 
@@ -792,9 +815,9 @@ class FederationHandler(BaseHandler):
 
             a.internal_metadata.outlier = True
             ev_infos.append(
-                {
-                    "event": a,
-                    "auth_events": {
+                _NewEventInfo(
+                    event=a,
+                    auth_events={
                         (
                             auth_events[a_id].type,
                             auth_events[a_id].state_key,
@@ -802,7 +825,7 @@ class FederationHandler(BaseHandler):
                         for a_id in a.auth_event_ids()
                         if a_id in auth_events
                     },
-                }
+                )
             )
 
         # Step 1b: persist the events in the chunk we fetched state for (i.e.
@@ -814,10 +837,10 @@ class FederationHandler(BaseHandler):
             assert not ev.internal_metadata.is_outlier()
 
             ev_infos.append(
-                {
-                    "event": ev,
-                    "state": events_to_state[e_id],
-                    "auth_events": {
+                _NewEventInfo(
+                    event=ev,
+                    state=events_to_state[e_id],
+                    auth_events={
                         (
                             auth_events[a_id].type,
                             auth_events[a_id].state_key,
@@ -825,7 +848,7 @@ class FederationHandler(BaseHandler):
                         for a_id in ev.auth_event_ids()
                         if a_id in auth_events
                     },
-                }
+                )
             )
 
         yield self._handle_new_events(dest, ev_infos, backfilled=True)
@@ -1428,9 +1451,9 @@ class FederationHandler(BaseHandler):
         return event
 
     @defer.inlineCallbacks
-    def do_remotely_reject_invite(self, target_hosts, room_id, user_id):
+    def do_remotely_reject_invite(self, target_hosts, room_id, user_id, content):
         origin, event, event_format_version = yield self._make_and_verify_event(
-            target_hosts, room_id, user_id, "leave"
+            target_hosts, room_id, user_id, "leave", content=content,
         )
         # Mark as outlier as we don't have any state for this event; we're not
         # even in the room.
@@ -1710,7 +1733,12 @@ class FederationHandler(BaseHandler):
         return context
 
     @defer.inlineCallbacks
-    def _handle_new_events(self, origin, event_infos, backfilled=False):
+    def _handle_new_events(
+        self,
+        origin: str,
+        event_infos: Iterable[_NewEventInfo],
+        backfilled: bool = False,
+    ):
         """Creates the appropriate contexts and persists events. The events
         should not depend on one another, e.g. this should be used to persist
         a bunch of outliers, but not a chunk of individual events that depend
@@ -1720,14 +1748,14 @@ class FederationHandler(BaseHandler):
         """
 
         @defer.inlineCallbacks
-        def prep(ev_info):
-            event = ev_info["event"]
+        def prep(ev_info: _NewEventInfo):
+            event = ev_info.event
             with nested_logging_context(suffix=event.event_id):
                 res = yield self._prep_event(
                     origin,
                     event,
-                    state=ev_info.get("state"),
-                    auth_events=ev_info.get("auth_events"),
+                    state=ev_info.state,
+                    auth_events=ev_info.auth_events,
                     backfilled=backfilled,
                 )
             return res
@@ -1741,7 +1769,7 @@ class FederationHandler(BaseHandler):
 
         yield self.persist_events_and_notify(
             [
-                (ev_info["event"], context)
+                (ev_info.event, context)
                 for ev_info, context in zip(event_infos, contexts)
             ],
             backfilled=backfilled,
@@ -1843,7 +1871,14 @@ class FederationHandler(BaseHandler):
         yield self.persist_events_and_notify([(event, new_event_context)])
 
     @defer.inlineCallbacks
-    def _prep_event(self, origin, event, state, auth_events, backfilled):
+    def _prep_event(
+        self,
+        origin: str,
+        event: EventBase,
+        state: Optional[Iterable[EventBase]],
+        auth_events: Optional[Dict[Tuple[str, str], EventBase]],
+        backfilled: bool,
+    ):
         """
 
         Args:
@@ -1851,7 +1886,7 @@ class FederationHandler(BaseHandler):
             event:
             state:
             auth_events:
-            backfilled (bool)
+            backfilled:
 
         Returns:
             Deferred, which resolves to synapse.events.snapshot.EventContext
@@ -1887,15 +1922,16 @@ class FederationHandler(BaseHandler):
         return context
 
     @defer.inlineCallbacks
-    def _check_for_soft_fail(self, event, state, backfilled):
+    def _check_for_soft_fail(
+        self, event: EventBase, state: Optional[Iterable[EventBase]], backfilled: bool
+    ):
         """Checks if we should soft fail the event, if so marks the event as
         such.
 
         Args:
-            event (FrozenEvent)
-            state (dict|None): The state at the event if we don't have all the
-                event's prev events
-            backfilled (bool): Whether the event is from backfill
+            event
+            state: The state at the event if we don't have all the event's prev events
+            backfilled: Whether the event is from backfill
 
         Returns:
             Deferred
@@ -2040,8 +2076,10 @@ class FederationHandler(BaseHandler):
             auth_events (dict[(str, str)->synapse.events.EventBase]):
                 Map from (event_type, state_key) to event
 
-                What we expect the event's auth_events to be, based on the event's
-                position in the dag. I think? maybe??
+                Normally, our calculated auth_events based on the state of the room
+                at the event's position in the DAG, though occasionally (eg if the
+                event is an outlier), may be the auth events claimed by the remote
+                server.
 
                 Also NB that this function adds entries to it.
         Returns:
@@ -2091,35 +2129,35 @@ class FederationHandler(BaseHandler):
             origin (str):
             event (synapse.events.EventBase):
             context (synapse.events.snapshot.EventContext):
+
             auth_events (dict[(str, str)->synapse.events.EventBase]):
+                Map from (event_type, state_key) to event
+
+                Normally, our calculated auth_events based on the state of the room
+                at the event's position in the DAG, though occasionally (eg if the
+                event is an outlier), may be the auth events claimed by the remote
+                server.
+
+                Also NB that this function adds entries to it.
 
         Returns:
             defer.Deferred[EventContext]: updated context
         """
         event_auth_events = set(event.auth_event_ids())
 
-        if event.is_state():
-            event_key = (event.type, event.state_key)
-        else:
-            event_key = None
-
-        # if the event's auth_events refers to events which are not in our
-        # calculated auth_events, we need to fetch those events from somewhere.
-        #
-        # we start by fetching them from the store, and then try calling /event_auth/.
+        # missing_auth is the set of the event's auth_events which we don't yet have
+        # in auth_events.
         missing_auth = event_auth_events.difference(
             e.event_id for e in auth_events.values()
         )
 
+        # if we have missing events, we need to fetch those events from somewhere.
+        #
+        # we start by checking if they are in the store, and then try calling /event_auth/.
         if missing_auth:
-            # TODO: can we use store.have_seen_events here instead?
-            have_events = yield self.store.get_seen_events_with_rejections(missing_auth)
-            logger.debug("Got events %s from store", have_events)
-            missing_auth.difference_update(have_events.keys())
-        else:
-            have_events = {}
-
-        have_events.update({e.event_id: "" for e in auth_events.values()})
+            have_events = yield self.store.have_seen_events(missing_auth)
+            logger.debug("Events %s are in the store", have_events)
+            missing_auth.difference_update(have_events)
 
         if missing_auth:
             # If we don't have all the auth events, we need to get them.
@@ -2165,19 +2203,18 @@ class FederationHandler(BaseHandler):
                     except AuthError:
                         pass
 
-                have_events = yield self.store.get_seen_events_with_rejections(
-                    event.auth_event_ids()
-                )
             except Exception:
-                # FIXME:
                 logger.exception("Failed to get auth chain")
 
         if event.internal_metadata.is_outlier():
+            # XXX: given that, for an outlier, we'll be working with the
+            # event's *claimed* auth events rather than those we calculated:
+            # (a) is there any point in this test, since different_auth below will
+            # obviously be empty
+            # (b) alternatively, why don't we do it earlier?
             logger.info("Skipping auth_event fetch for outlier")
             return context
 
-        # FIXME: Assumes we have and stored all the state for all the
-        # prev_events
         different_auth = event_auth_events.difference(
             e.event_id for e in auth_events.values()
         )
@@ -2191,53 +2228,58 @@ class FederationHandler(BaseHandler):
             different_auth,
         )
 
-        room_version = yield self.store.get_room_version(event.room_id)
+        # XXX: currently this checks for redactions but I'm not convinced that is
+        # necessary?
+        different_events = yield self.store.get_events_as_list(different_auth)
 
-        different_events = yield make_deferred_yieldable(
-            defer.gatherResults(
-                [
-                    run_in_background(
-                        self.store.get_event, d, allow_none=True, allow_rejected=False
-                    )
-                    for d in different_auth
-                    if d in have_events and not have_events[d]
-                ],
-                consumeErrors=True,
-            )
-        ).addErrback(unwrapFirstError)
+        for d in different_events:
+            if d.room_id != event.room_id:
+                logger.warning(
+                    "Event %s refers to auth_event %s which is in a different room",
+                    event.event_id,
+                    d.event_id,
+                )
 
-        if different_events:
-            local_view = dict(auth_events)
-            remote_view = dict(auth_events)
-            remote_view.update(
-                {(d.type, d.state_key): d for d in different_events if d}
-            )
+                # don't attempt to resolve the claimed auth events against our own
+                # in this case: just use our own auth events.
+                #
+                # XXX: should we reject the event in this case? It feels like we should,
+                # but then shouldn't we also do so if we've failed to fetch any of the
+                # auth events?
+                return context
 
-            new_state = yield self.state_handler.resolve_events(
-                room_version,
-                [list(local_view.values()), list(remote_view.values())],
-                event,
-            )
+        # now we state-resolve between our own idea of the auth events, and the remote's
+        # idea of them.
 
-            logger.info(
-                "After state res: updating auth_events with new state %s",
-                {
-                    (d.type, d.state_key): d.event_id
-                    for d in new_state.values()
-                    if auth_events.get((d.type, d.state_key)) != d
-                },
-            )
+        local_state = auth_events.values()
+        remote_auth_events = dict(auth_events)
+        remote_auth_events.update({(d.type, d.state_key): d for d in different_events})
+        remote_state = remote_auth_events.values()
+
+        room_version = yield self.store.get_room_version(event.room_id)
+        new_state = yield self.state_handler.resolve_events(
+            room_version, (local_state, remote_state), event
+        )
+
+        logger.info(
+            "After state res: updating auth_events with new state %s",
+            {
+                (d.type, d.state_key): d.event_id
+                for d in new_state.values()
+                if auth_events.get((d.type, d.state_key)) != d
+            },
+        )
 
-            auth_events.update(new_state)
+        auth_events.update(new_state)
 
-            context = yield self._update_context_for_auth_events(
-                event, context, auth_events, event_key
-            )
+        context = yield self._update_context_for_auth_events(
+            event, context, auth_events
+        )
 
         return context
 
     @defer.inlineCallbacks
-    def _update_context_for_auth_events(self, event, context, auth_events, event_key):
+    def _update_context_for_auth_events(self, event, context, auth_events):
         """Update the state_ids in an event context after auth event resolution,
         storing the changes as a new state group.
 
@@ -2246,18 +2288,21 @@ class FederationHandler(BaseHandler):
 
             context (synapse.events.snapshot.EventContext): initial event context
 
-            auth_events (dict[(str, str)->str]): Events to update in the event
+            auth_events (dict[(str, str)->EventBase]): Events to update in the event
                 context.
 
-            event_key ((str, str)): (type, state_key) for the current event.
-                this will not be included in the current_state in the context.
-
         Returns:
             Deferred[EventContext]: new event context
         """
+        # exclude the state key of the new event from the current_state in the context.
+        if event.is_state():
+            event_key = (event.type, event.state_key)
+        else:
+            event_key = None
         state_updates = {
             k: a.event_id for k, a in iteritems(auth_events) if k != event_key
         }
+
         current_state_ids = yield context.get_current_state_ids(self.store)
         current_state_ids = dict(current_state_ids)
 
@@ -2459,7 +2504,7 @@ class FederationHandler(BaseHandler):
                 room_version, event_dict, event, context
             )
 
-            EventValidator().validate_new(event)
+            EventValidator().validate_new(event, self.config)
 
             # We need to tell the transaction queue to send this out, even
             # though the sender isn't a local user.
@@ -2574,7 +2619,7 @@ class FederationHandler(BaseHandler):
         event, context = yield self.event_creation_handler.create_new_client_event(
             builder=builder
         )
-        EventValidator().validate_new(event)
+        EventValidator().validate_new(event, self.config)
         return (event, context)
 
     @defer.inlineCallbacks
@@ -2708,6 +2753,11 @@ class FederationHandler(BaseHandler):
                 event_and_contexts, backfilled=backfilled
             )
 
+            if self._ephemeral_messages_enabled:
+                for (event, context) in event_and_contexts:
+                    # If there's an expiry timestamp on the event, schedule its expiry.
+                    self._message_handler.maybe_schedule_expiry(event)
+
             if not backfilled:  # Never notify for backfilled events
                 for event, _ in event_and_contexts:
                     yield self._notify_persisted_event(event, max_stream_id)