Add base starting insertion event when no chunk ID is provided (MSC2716) (#10250)

* Add base starting insertion point when no chunk ID is provided

This is so we can have the marker event point to this initial
insertion event and be able to traverse the events in the first chunk.
This commit is contained in:
Eric Eastwood 2021-07-08 20:25:59 -05:00 committed by GitHub
parent 33ae301fee
commit d26094e92c
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 99 additions and 24 deletions

1
changelog.d/10250.bugfix Normal file
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@ -0,0 +1 @@
Add base starting insertion event when no chunk ID is specified in the historical batch send API.

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@ -518,6 +518,9 @@ class EventCreationHandler:
outlier: Indicates whether the event is an `outlier`, i.e. if
it's from an arbitrary point and floating in the DAG as
opposed to being inline with the current DAG.
historical: Indicates whether the message is being inserted
back in time around some existing events. This is used to skip
a few checks and mark the event as backfilled.
depth: Override the depth used to order the event in the DAG.
Should normally be set to None, which will cause the depth to be calculated
based on the prev_events.
@ -772,6 +775,7 @@ class EventCreationHandler:
txn_id: Optional[str] = None,
ignore_shadow_ban: bool = False,
outlier: bool = False,
historical: bool = False,
depth: Optional[int] = None,
) -> Tuple[EventBase, int]:
"""
@ -799,6 +803,9 @@ class EventCreationHandler:
outlier: Indicates whether the event is an `outlier`, i.e. if
it's from an arbitrary point and floating in the DAG as
opposed to being inline with the current DAG.
historical: Indicates whether the message is being inserted
back in time around some existing events. This is used to skip
a few checks and mark the event as backfilled.
depth: Override the depth used to order the event in the DAG.
Should normally be set to None, which will cause the depth to be calculated
based on the prev_events.
@ -847,6 +854,7 @@ class EventCreationHandler:
prev_event_ids=prev_event_ids,
auth_event_ids=auth_event_ids,
outlier=outlier,
historical=historical,
depth=depth,
)

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@ -349,6 +349,35 @@ class RoomBatchSendEventRestServlet(TransactionRestServlet):
return depth
def _create_insertion_event_dict(
self, sender: str, room_id: str, origin_server_ts: int
):
"""Creates an event dict for an "insertion" event with the proper fields
and a random chunk ID.
Args:
sender: The event author MXID
room_id: The room ID that the event belongs to
origin_server_ts: Timestamp when the event was sent
Returns:
Tuple of event ID and stream ordering position
"""
next_chunk_id = random_string(8)
insertion_event = {
"type": EventTypes.MSC2716_INSERTION,
"sender": sender,
"room_id": room_id,
"content": {
EventContentFields.MSC2716_NEXT_CHUNK_ID: next_chunk_id,
EventContentFields.MSC2716_HISTORICAL: True,
},
"origin_server_ts": origin_server_ts,
}
return insertion_event
async def on_POST(self, request, room_id):
requester = await self.auth.get_user_by_req(request, allow_guest=False)
@ -449,37 +478,68 @@ class RoomBatchSendEventRestServlet(TransactionRestServlet):
events_to_create = body["events"]
# If provided, connect the chunk to the last insertion point
# The chunk ID passed in comes from the chunk_id in the
# "insertion" event from the previous chunk.
if chunk_id_from_query:
last_event_in_chunk = events_to_create[-1]
last_event_in_chunk["content"][
EventContentFields.MSC2716_CHUNK_ID
] = chunk_id_from_query
prev_event_ids = prev_events_from_query
inherited_depth = await self.inherit_depth_from_prev_ids(prev_events_from_query)
# Add an "insertion" event to the start of each chunk (next to the oldest
# Figure out which chunk to connect to. If they passed in
# chunk_id_from_query let's use it. The chunk ID passed in comes
# from the chunk_id in the "insertion" event from the previous chunk.
last_event_in_chunk = events_to_create[-1]
chunk_id_to_connect_to = chunk_id_from_query
base_insertion_event = None
if chunk_id_from_query:
# TODO: Verify the chunk_id_from_query corresponds to an insertion event
pass
# Otherwise, create an insertion event to act as a starting point.
#
# We don't always have an insertion event to start hanging more history
# off of (ideally there would be one in the main DAG, but that's not the
# case if we're wanting to add history to e.g. existing rooms without
# an insertion event), in which case we just create a new insertion event
# that can then get pointed to by a "marker" event later.
else:
base_insertion_event_dict = self._create_insertion_event_dict(
sender=requester.user.to_string(),
room_id=room_id,
origin_server_ts=last_event_in_chunk["origin_server_ts"],
)
base_insertion_event_dict["prev_events"] = prev_event_ids.copy()
(
base_insertion_event,
_,
) = await self.event_creation_handler.create_and_send_nonmember_event(
requester,
base_insertion_event_dict,
prev_event_ids=base_insertion_event_dict.get("prev_events"),
auth_event_ids=auth_event_ids,
historical=True,
depth=inherited_depth,
)
chunk_id_to_connect_to = base_insertion_event["content"][
EventContentFields.MSC2716_NEXT_CHUNK_ID
]
# Connect this current chunk to the insertion event from the previous chunk
last_event_in_chunk["content"][
EventContentFields.MSC2716_CHUNK_ID
] = chunk_id_to_connect_to
# Add an "insertion" event to the start of each chunk (next to the oldest-in-time
# event in the chunk) so the next chunk can be connected to this one.
next_chunk_id = random_string(64)
insertion_event = {
"type": EventTypes.MSC2716_INSERTION,
"sender": requester.user.to_string(),
"content": {
EventContentFields.MSC2716_NEXT_CHUNK_ID: next_chunk_id,
EventContentFields.MSC2716_HISTORICAL: True,
},
insertion_event = self._create_insertion_event_dict(
sender=requester.user.to_string(),
room_id=room_id,
# Since the insertion event is put at the start of the chunk,
# where the oldest event is, copy the origin_server_ts from
# where the oldest-in-time event is, copy the origin_server_ts from
# the first event we're inserting
"origin_server_ts": events_to_create[0]["origin_server_ts"],
}
origin_server_ts=events_to_create[0]["origin_server_ts"],
)
# Prepend the insertion event to the start of the chunk
events_to_create = [insertion_event] + events_to_create
inherited_depth = await self.inherit_depth_from_prev_ids(prev_events_from_query)
event_ids = []
prev_event_ids = prev_events_from_query
events_to_persist = []
for ev in events_to_create:
assert_params_in_dict(ev, ["type", "origin_server_ts", "content", "sender"])
@ -533,10 +593,16 @@ class RoomBatchSendEventRestServlet(TransactionRestServlet):
context=context,
)
# Add the base_insertion_event to the bottom of the list we return
if base_insertion_event is not None:
event_ids.append(base_insertion_event.event_id)
return 200, {
"state_events": auth_event_ids,
"events": event_ids,
"next_chunk_id": next_chunk_id,
"next_chunk_id": insertion_event["content"][
EventContentFields.MSC2716_NEXT_CHUNK_ID
],
}
def on_GET(self, request, room_id):