diff --git a/synapse/events/snapshot.py b/synapse/events/snapshot.py
index a269de5482..5f07f6fe4b 100644
--- a/synapse/events/snapshot.py
+++ b/synapse/events/snapshot.py
@@ -12,6 +12,8 @@
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
+from typing import Dict, Optional, Tuple, Union
+
from six import iteritems
import attr
@@ -19,45 +21,82 @@ from frozendict import frozendict
from twisted.internet import defer
+from synapse.appservice import ApplicationService
from synapse.logging.context import make_deferred_yieldable, run_in_background
@attr.s(slots=True)
class EventContext:
"""
+ Holds information relevant to persisting an event
+
Attributes:
- state_group (int|None): state group id, if the state has been stored
- as a state group. This is usually only None if e.g. the event is
- an outlier.
- rejected (bool|str): A rejection reason if the event was rejected, else
- False
-
- prev_group (int): Previously persisted state group. ``None`` for an
- outlier.
- delta_ids (dict[(str, str), str]): Delta from ``prev_group``.
- (type, state_key) -> event_id. ``None`` for an outlier.
-
- app_service: FIXME
-
- _current_state_ids (dict[(str, str), str]|None):
- The current state map including the current event. None if outlier
- or we haven't fetched the state from DB yet.
+ rejected: A rejection reason if the event was rejected, else False
+
+ state_group: The ID of the state group for this event. Note that state events
+ are persisted with a state group which includes the new event, so this is
+ effectively the state *after* the event in question.
+
+ For a *rejected* state event, where the state of the rejected event is
+ ignored, this state_group should never make it into the
+ event_to_state_groups table. Indeed, inspecting this value for a rejected
+ state event is almost certainly incorrect.
+
+ For an outlier, where we don't have the state at the event, this will be
+ None.
+
+ prev_group: If it is known, ``state_group``'s prev_group. Note that this being
+ None does not necessarily mean that ``state_group`` does not have
+ a prev_group!
+
+ If ``state_group`` is None (ie, the event is an outlier), ``prev_group``
+ will always also be ``None``.
+
+ Note that this *not* (necessarily) the state group associated with
+ ``_prev_state_ids``.
+
+ delta_ids: If ``prev_group`` is not None, the state delta between ``prev_group``
+ and ``state_group``.
+
+ app_service: If this event is being sent by a (local) application service, that
+ app service.
+
+ _current_state_ids: The room state map, including this event - ie, the state
+ in ``state_group``.
+
(type, state_key) -> event_id
- _prev_state_ids (dict[(str, str), str]|None):
- The current state map excluding the current event. None if outlier
- or we haven't fetched the state from DB yet.
+ FIXME: what is this for an outlier? it seems ill-defined. It seems like
+ it could be either {}, or the state we were given by the remote
+ server, depending on $THINGS
+
+ Note that this is a private attribute: it should be accessed via
+ ``get_current_state_ids``. _AsyncEventContext impl calculates this
+ on-demand: it will be None until that happens.
+
+ _prev_state_ids: The room state map, excluding this event. For a non-state
+ event, this will be the same as _current_state_events.
+
+ Note that it is a completely different thing to prev_group!
+
(type, state_key) -> event_id
+
+ FIXME: again, what is this for an outlier?
+
+ As with _current_state_ids, this is a private attribute. It should be
+ accessed via get_prev_state_ids.
"""
- state_group = attr.ib(default=None)
- rejected = attr.ib(default=False)
- prev_group = attr.ib(default=None)
- delta_ids = attr.ib(default=None)
- app_service = attr.ib(default=None)
+ rejected = attr.ib(default=False, type=Union[bool, str])
+ state_group = attr.ib(default=None, type=Optional[int])
+ prev_group = attr.ib(default=None, type=Optional[int])
+ delta_ids = attr.ib(default=None, type=Optional[Dict[Tuple[str, str], str]])
+ app_service = attr.ib(default=None, type=Optional[ApplicationService])
- _prev_state_ids = attr.ib(default=None)
- _current_state_ids = attr.ib(default=None)
+ _current_state_ids = attr.ib(
+ default=None, type=Optional[Dict[Tuple[str, str], str]]
+ )
+ _prev_state_ids = attr.ib(default=None, type=Optional[Dict[Tuple[str, str], str]])
@staticmethod
def with_state(
|
