diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 96f37e9f42..bcd10cbb30 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -1662,20 +1662,20 @@ class SyncHandler:
) -> _RoomChanges:
"""Determine the changes in rooms to report to the user.
- Ideally, we want to report all events whose stream ordering `s` lies in the
- range `since_token < s <= now_token`, where the two tokens are read from the
- sync_result_builder.
+ This function is a first pass at generating the rooms part of the sync response.
+ It determines which rooms have changed during the sync period, and categorises
+ them into four buckets: "knock", "invite", "join" and "leave".
- If there are too many events in that range to report, things get complicated.
- In this situation we return a truncated list of the most recent events, and
- indicate in the response that there is a "gap" of omitted events. Additionally:
+ 1. Finds all membership changes for the user in the sync period (from
+ `since_token` up to `now_token`).
+ 2. Uses those to place the room in one of the four categories above.
+ 3. Builds a `_RoomChanges` struct to record this, and return that struct.
- - we include a "state_delta", to describe the changes in state over the gap,
- - we include all membership events applying to the user making the request,
- even those in the gap.
-
- See the spec for the rationale:
- https://spec.matrix.org/v1.1/client-server-api/#syncing
+ For rooms classified as "knock", "invite" or "leave", we just need to report
+ a single membership event in the eventual /sync response. For "join" we need
+ to fetch additional non-membership events, e.g. messages in the room. That is
+ more complicated, so instead we report an intermediary `RoomSyncResultBuilder`
+ struct, and leave the additional work to `_generate_room_entry`.
The sync_result_builder is not modified by this function.
"""
@@ -1686,16 +1686,6 @@ class SyncHandler:
assert since_token
- # The spec
- # https://spec.matrix.org/v1.1/client-server-api/#get_matrixclientv3sync
- # notes that membership events need special consideration:
- #
- # > When a sync is limited, the server MUST return membership events for events
- # > in the gap (between since and the start of the returned timeline), regardless
- # > as to whether or not they are redundant.
- #
- # We fetch such events here, but we only seem to use them for categorising rooms
- # as newly joined, newly left, invited or knocked.
# TODO: we've already called this function and ran this query in
# _have_rooms_changed. We could keep the results in memory to avoid a
# second query, at the cost of more complicated source code.
@@ -2009,6 +1999,23 @@ class SyncHandler:
"""Populates the `joined` and `archived` section of `sync_result_builder`
based on the `room_builder`.
+ Ideally, we want to report all events whose stream ordering `s` lies in the
+ range `since_token < s <= now_token`, where the two tokens are read from the
+ sync_result_builder.
+
+ If there are too many events in that range to report, things get complicated.
+ In this situation we return a truncated list of the most recent events, and
+ indicate in the response that there is a "gap" of omitted events. Lots of this
+ is handled in `_load_filtered_recents`, but some of is handled in this method.
+
+ Additionally:
+ - we include a "state_delta", to describe the changes in state over the gap,
+ - we include all membership events applying to the user making the request,
+ even those in the gap.
+
+ See the spec for the rationale:
+ https://spec.matrix.org/v1.1/client-server-api/#syncing
+
Args:
sync_result_builder
ignored_users: Set of users ignored by user.
|
