diff --git a/synapse/events/snapshot.py b/synapse/events/snapshot.py
index 87e3fe7b97..7b80444f73 100644
--- a/synapse/events/snapshot.py
+++ b/synapse/events/snapshot.py
@@ -14,6 +14,9 @@
# limitations under the License.
+from frozendict import frozendict
+
+
class EventContext(object):
"""
Attributes:
@@ -73,3 +76,72 @@ class EventContext(object):
self.prev_state_events = None
self.app_service = None
+
+ def serialize(self):
+ """Converts self to a type that can be serialized as JSON, and then
+ deserialized by `deserialize`
+
+ Returns:
+ dict
+ """
+ return {
+ "current_state_ids": _encode_state_dict(self.current_state_ids),
+ "prev_state_ids": _encode_state_dict(self.prev_state_ids),
+ "state_group": self.state_group,
+ "rejected": self.rejected,
+ "push_actions": self.push_actions,
+ "prev_group": self.prev_group,
+ "delta_ids": _encode_state_dict(self.delta_ids),
+ "prev_state_events": self.prev_state_events,
+ "app_service_id": self.app_service.id if self.app_service else None
+ }
+
+ @staticmethod
+ def deserialize(store, input):
+ """Converts a dict that was produced by `serialize` back into a
+ EventContext.
+
+ Args:
+ store (DataStore): Used to convert AS ID to AS object
+ input (dict): A dict produced by `serialize`
+
+ Returns:
+ EventContext
+ """
+ context = EventContext()
+ context.current_state_ids = _decode_state_dict(input["current_state_ids"])
+ context.prev_state_ids = _decode_state_dict(input["prev_state_ids"])
+ context.state_group = input["state_group"]
+ context.rejected = input["rejected"]
+ context.push_actions = input["push_actions"]
+ context.prev_group = input["prev_group"]
+ context.delta_ids = _decode_state_dict(input["delta_ids"])
+ context.prev_state_events = input["prev_state_events"]
+
+ app_service_id = input["app_service_id"]
+ if app_service_id:
+ context.app_service = store.get_app_service_by_id(app_service_id)
+
+ return context
+
+
+def _encode_state_dict(state_dict):
+ """Since dicts of (type, state_key) -> event_id cannot be serialized in
+ JSON we need to convert them to a form that can.
+ """
+ if state_dict is None:
+ return None
+
+ return [
+ (etype, state_key, v)
+ for (etype, state_key), v in state_dict.iteritems()
+ ]
+
+
+def _decode_state_dict(input):
+ """Decodes a state dict encoded using `_encode_state_dict` above
+ """
+ if input is None:
+ return None
+
+ return frozendict({(etype, state_key,): v for etype, state_key, v in input})
|
