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Diffstat (limited to 'synapse/rest/client/room_batch.py')
| -rw-r--r-- | synapse/rest/client/room_batch.py | 441 |
1 files changed, 441 insertions, 0 deletions
diff --git a/synapse/rest/client/room_batch.py b/synapse/rest/client/room_batch.py new file mode 100644 index 0000000000..3172aba605 --- /dev/null +++ b/synapse/rest/client/room_batch.py @@ -0,0 +1,441 @@ +# Copyright 2016 OpenMarket Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# 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. + +import logging +import re + +from synapse.api.constants import EventContentFields, EventTypes +from synapse.api.errors import AuthError, Codes, SynapseError +from synapse.appservice import ApplicationService +from synapse.http.servlet import ( + RestServlet, + assert_params_in_dict, + parse_json_object_from_request, + parse_string, + parse_strings_from_args, +) +from synapse.rest.client.transactions import HttpTransactionCache +from synapse.types import Requester, UserID, create_requester +from synapse.util.stringutils import random_string + +logger = logging.getLogger(__name__) + + +class RoomBatchSendEventRestServlet(RestServlet): + """ + API endpoint which can insert a chunk of events historically back in time + next to the given `prev_event`. + + `chunk_id` comes from `next_chunk_id `in the response of the batch send + endpoint and is derived from the "insertion" events added to each chunk. + It's not required for the first batch send. + + `state_events_at_start` is used to define the historical state events + needed to auth the events like join events. These events will float + outside of the normal DAG as outlier's and won't be visible in the chat + history which also allows us to insert multiple chunks without having a bunch + of `@mxid joined the room` noise between each chunk. + + `events` is chronological chunk/list of events you want to insert. + There is a reverse-chronological constraint on chunks so once you insert + some messages, you can only insert older ones after that. + tldr; Insert chunks from your most recent history -> oldest history. + + POST /_matrix/client/unstable/org.matrix.msc2716/rooms/<roomID>/batch_send?prev_event=<eventID>&chunk_id=<chunkID> + { + "events": [ ... ], + "state_events_at_start": [ ... ] + } + """ + + PATTERNS = ( + re.compile( + "^/_matrix/client/unstable/org.matrix.msc2716" + "/rooms/(?P<room_id>[^/]*)/batch_send$" + ), + ) + + def __init__(self, hs): + super().__init__() + self.hs = hs + self.store = hs.get_datastore() + self.state_store = hs.get_storage().state + self.event_creation_handler = hs.get_event_creation_handler() + self.room_member_handler = hs.get_room_member_handler() + self.auth = hs.get_auth() + self.txns = HttpTransactionCache(hs) + + async def _inherit_depth_from_prev_ids(self, prev_event_ids) -> int: + ( + most_recent_prev_event_id, + most_recent_prev_event_depth, + ) = await self.store.get_max_depth_of(prev_event_ids) + + # We want to insert the historical event after the `prev_event` but before the successor event + # + # We inherit depth from the successor event instead of the `prev_event` + # because events returned from `/messages` are first sorted by `topological_ordering` + # which is just the `depth` and then tie-break with `stream_ordering`. + # + # We mark these inserted historical events as "backfilled" which gives them a + # negative `stream_ordering`. If we use the same depth as the `prev_event`, + # then our historical event will tie-break and be sorted before the `prev_event` + # when it should come after. + # + # We want to use the successor event depth so they appear after `prev_event` because + # it has a larger `depth` but before the successor event because the `stream_ordering` + # is negative before the successor event. + successor_event_ids = await self.store.get_successor_events( + [most_recent_prev_event_id] + ) + + # If we can't find any successor events, then it's a forward extremity of + # historical messages and we can just inherit from the previous historical + # event which we can already assume has the correct depth where we want + # to insert into. + if not successor_event_ids: + depth = most_recent_prev_event_depth + else: + ( + _, + oldest_successor_depth, + ) = await self.store.get_min_depth_of(successor_event_ids) + + depth = oldest_successor_depth + + 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 _create_requester_for_user_id_from_app_service( + self, user_id: str, app_service: ApplicationService + ) -> Requester: + """Creates a new requester for the given user_id + and validates that the app service is allowed to control + the given user. + + Args: + user_id: The author MXID that the app service is controlling + app_service: The app service that controls the user + + Returns: + Requester object + """ + + await self.auth.validate_appservice_can_control_user_id(app_service, user_id) + + return create_requester(user_id, app_service=app_service) + + async def on_POST(self, request, room_id): + requester = await self.auth.get_user_by_req(request, allow_guest=False) + + if not requester.app_service: + raise AuthError( + 403, + "Only application services can use the /batchsend endpoint", + ) + + body = parse_json_object_from_request(request) + assert_params_in_dict(body, ["state_events_at_start", "events"]) + + prev_events_from_query = parse_strings_from_args(request.args, "prev_event") + chunk_id_from_query = parse_string(request, "chunk_id") + + if prev_events_from_query is None: + raise SynapseError( + 400, + "prev_event query parameter is required when inserting historical messages back in time", + errcode=Codes.MISSING_PARAM, + ) + + # For the event we are inserting next to (`prev_events_from_query`), + # find the most recent auth events (derived from state events) that + # allowed that message to be sent. We will use that as a base + # to auth our historical messages against. + ( + most_recent_prev_event_id, + _, + ) = await self.store.get_max_depth_of(prev_events_from_query) + # mapping from (type, state_key) -> state_event_id + prev_state_map = await self.state_store.get_state_ids_for_event( + most_recent_prev_event_id + ) + # List of state event ID's + prev_state_ids = list(prev_state_map.values()) + auth_event_ids = prev_state_ids + + state_events_at_start = [] + for state_event in body["state_events_at_start"]: + assert_params_in_dict( + state_event, ["type", "origin_server_ts", "content", "sender"] + ) + + logger.debug( + "RoomBatchSendEventRestServlet inserting state_event=%s, auth_event_ids=%s", + state_event, + auth_event_ids, + ) + + event_dict = { + "type": state_event["type"], + "origin_server_ts": state_event["origin_server_ts"], + "content": state_event["content"], + "room_id": room_id, + "sender": state_event["sender"], + "state_key": state_event["state_key"], + } + + # Mark all events as historical + event_dict["content"][EventContentFields.MSC2716_HISTORICAL] = True + + # Make the state events float off on their own + fake_prev_event_id = "$" + random_string(43) + + # TODO: This is pretty much the same as some other code to handle inserting state in this file + if event_dict["type"] == EventTypes.Member: + membership = event_dict["content"].get("membership", None) + event_id, _ = await self.room_member_handler.update_membership( + await self._create_requester_for_user_id_from_app_service( + state_event["sender"], requester.app_service + ), + target=UserID.from_string(event_dict["state_key"]), + room_id=room_id, + action=membership, + content=event_dict["content"], + outlier=True, + prev_event_ids=[fake_prev_event_id], + # Make sure to use a copy of this list because we modify it + # later in the loop here. Otherwise it will be the same + # reference and also update in the event when we append later. + auth_event_ids=auth_event_ids.copy(), + ) + else: + # TODO: Add some complement tests that adds state that is not member joins + # and will use this code path. Maybe we only want to support join state events + # and can get rid of this `else`? + ( + event, + _, + ) = await self.event_creation_handler.create_and_send_nonmember_event( + await self._create_requester_for_user_id_from_app_service( + state_event["sender"], requester.app_service + ), + event_dict, + outlier=True, + prev_event_ids=[fake_prev_event_id], + # Make sure to use a copy of this list because we modify it + # later in the loop here. Otherwise it will be the same + # reference and also update in the event when we append later. + auth_event_ids=auth_event_ids.copy(), + ) + event_id = event.event_id + + state_events_at_start.append(event_id) + auth_event_ids.append(event_id) + + events_to_create = body["events"] + + inherited_depth = await self._inherit_depth_from_prev_ids( + prev_events_from_query + ) + + # 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: + # All but the first base insertion event should point at a fake + # event, which causes the HS to ask for the state at the start of + # the chunk later. + prev_event_ids = [fake_prev_event_id] + # 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: + prev_event_ids = prev_events_from_query + + 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( + await self._create_requester_for_user_id_from_app_service( + base_insertion_event_dict["sender"], + requester.app_service, + ), + 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 + chunk_event = { + "type": EventTypes.MSC2716_CHUNK, + "sender": requester.user.to_string(), + "room_id": room_id, + "content": { + EventContentFields.MSC2716_CHUNK_ID: chunk_id_to_connect_to, + EventContentFields.MSC2716_HISTORICAL: True, + }, + # Since the chunk event is put at the end of the chunk, + # where the newest-in-time event is, copy the origin_server_ts from + # the last event we're inserting + "origin_server_ts": last_event_in_chunk["origin_server_ts"], + } + # Add the chunk event to the end of the chunk (newest-in-time) + events_to_create.append(chunk_event) + + # 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. + 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-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"], + ) + # Prepend the insertion event to the start of the chunk (oldest-in-time) + events_to_create = [insertion_event] + events_to_create + + event_ids = [] + events_to_persist = [] + for ev in events_to_create: + assert_params_in_dict(ev, ["type", "origin_server_ts", "content", "sender"]) + + event_dict = { + "type": ev["type"], + "origin_server_ts": ev["origin_server_ts"], + "content": ev["content"], + "room_id": room_id, + "sender": ev["sender"], # requester.user.to_string(), + "prev_events": prev_event_ids.copy(), + } + + # Mark all events as historical + event_dict["content"][EventContentFields.MSC2716_HISTORICAL] = True + + event, context = await self.event_creation_handler.create_event( + await self._create_requester_for_user_id_from_app_service( + ev["sender"], requester.app_service + ), + event_dict, + prev_event_ids=event_dict.get("prev_events"), + auth_event_ids=auth_event_ids, + historical=True, + depth=inherited_depth, + ) + logger.debug( + "RoomBatchSendEventRestServlet inserting event=%s, prev_event_ids=%s, auth_event_ids=%s", + event, + prev_event_ids, + auth_event_ids, + ) + + assert self.hs.is_mine_id(event.sender), "User must be our own: %s" % ( + event.sender, + ) + + events_to_persist.append((event, context)) + event_id = event.event_id + + event_ids.append(event_id) + prev_event_ids = [event_id] + + # Persist events in reverse-chronological order so they have the + # correct stream_ordering as they are backfilled (which decrements). + # Events are sorted by (topological_ordering, stream_ordering) + # where topological_ordering is just depth. + for (event, context) in reversed(events_to_persist): + ev = await self.event_creation_handler.handle_new_client_event( + await self._create_requester_for_user_id_from_app_service( + event["sender"], requester.app_service + ), + event=event, + 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": state_events_at_start, + "events": event_ids, + "next_chunk_id": insertion_event["content"][ + EventContentFields.MSC2716_NEXT_CHUNK_ID + ], + } + + def on_GET(self, request, room_id): + return 501, "Not implemented" + + def on_PUT(self, request, room_id): + return self.txns.fetch_or_execute_request( + request, self.on_POST, request, room_id + ) + + +def register_servlets(hs, http_server): + msc2716_enabled = hs.config.experimental.msc2716_enabled + + if msc2716_enabled: + RoomBatchSendEventRestServlet(hs).register(http_server) |