diff --git a/changelog.d/10498.feature b/changelog.d/10498.feature new file mode 100644 index 0000000000..5df896572d --- /dev/null +++ b/changelog.d/10498.feature @@ -0,0 +1 @@ +Add support for "marker" events which makes historical events discoverable for servers that already have all of the scrollback history (part of MSC2716). diff --git a/scripts-dev/complement.sh b/scripts-dev/complement.sh index cba015d942..5d0ef8dd3a 100755 --- a/scripts-dev/complement.sh +++ b/scripts-dev/complement.sh @@ -65,4 +65,4 @@ if [[ -n "$1" ]]; then fi # Run the tests! -go test -v -tags synapse_blacklist,msc2946,msc3083,msc2403 -count=1 $EXTRA_COMPLEMENT_ARGS ./tests/... +go test -v -tags synapse_blacklist,msc2946,msc3083,msc2403,msc2716 -count=1 $EXTRA_COMPLEMENT_ARGS ./tests/... diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 8197b60b76..8b602e3813 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -42,6 +42,7 @@ from twisted.internet import defer from synapse import event_auth from synapse.api.constants import ( + EventContentFields, EventTypes, Membership, RejectedReason, @@ -262,7 +263,12 @@ class FederationHandler(BaseHandler): state = None - # Get missing pdus if necessary. + # Check that the event passes auth based on the state at the event. This is + # done for events that are to be added to the timeline (non-outliers). + # + # Get missing pdus if necessary: + # - Fetching any missing prev events to fill in gaps in the graph + # - Fetching state if we have a hole in the graph if not pdu.internal_metadata.is_outlier(): # We only backfill backwards to the min depth. min_depth = await self.get_min_depth_for_context(pdu.room_id) @@ -432,6 +438,13 @@ class FederationHandler(BaseHandler): affected=event_id, ) + # A second round of checks for all events. Check that the event passes auth + # based on `auth_events`, this allows us to assert that the event would + # have been allowed at some point. If an event passes this check its OK + # for it to be used as part of a returned `/state` request, as either + # a) we received the event as part of the original join and so trust it, or + # b) we'll do a state resolution with existing state before it becomes + # part of the "current state", which adds more protection. await self._process_received_pdu(origin, pdu, state=state) async def _get_missing_events_for_pdu( @@ -889,6 +902,79 @@ class FederationHandler(BaseHandler): "resync_device_due_to_pdu", self._resync_device, event.sender ) + await self._handle_marker_event(origin, event) + + async def _handle_marker_event(self, origin: str, marker_event: EventBase): + """Handles backfilling the insertion event when we receive a marker + event that points to one. + + Args: + origin: Origin of the event. Will be called to get the insertion event + marker_event: The event to process + """ + + if marker_event.type != EventTypes.MSC2716_MARKER: + # Not a marker event + return + + if marker_event.rejected_reason is not None: + # Rejected event + return + + # Skip processing a marker event if the room version doesn't + # support it. + room_version = await self.store.get_room_version(marker_event.room_id) + if not room_version.msc2716_historical: + return + + logger.debug("_handle_marker_event: received %s", marker_event) + + insertion_event_id = marker_event.content.get( + EventContentFields.MSC2716_MARKER_INSERTION + ) + + if insertion_event_id is None: + # Nothing to retrieve then (invalid marker) + return + + logger.debug( + "_handle_marker_event: backfilling insertion event %s", insertion_event_id + ) + + await self._get_events_and_persist( + origin, + marker_event.room_id, + [insertion_event_id], + ) + + insertion_event = await self.store.get_event( + insertion_event_id, allow_none=True + ) + if insertion_event is None: + logger.warning( + "_handle_marker_event: server %s didn't return insertion event %s for marker %s", + origin, + insertion_event_id, + marker_event.event_id, + ) + return + + logger.debug( + "_handle_marker_event: succesfully backfilled insertion event %s from marker event %s", + insertion_event, + marker_event, + ) + + await self.store.insert_insertion_extremity( + insertion_event_id, marker_event.room_id + ) + + logger.debug( + "_handle_marker_event: insertion extremity added for %s from marker event %s", + insertion_event, + marker_event, + ) + async def _resync_device(self, sender: str) -> None: """We have detected that the device list for the given user may be out of sync, so we try and resync them. @@ -1057,9 +1143,19 @@ class FederationHandler(BaseHandler): async def _maybe_backfill_inner( self, room_id: str, current_depth: int, limit: int ) -> bool: - extremities = await self.store.get_oldest_events_with_depth_in_room(room_id) + oldest_events_with_depth = ( + await self.store.get_oldest_event_ids_with_depth_in_room(room_id) + ) + insertion_events_to_be_backfilled = ( + await self.store.get_insertion_event_backwards_extremities_in_room(room_id) + ) + logger.debug( + "_maybe_backfill_inner: extremities oldest_events_with_depth=%s insertion_events_to_be_backfilled=%s", + oldest_events_with_depth, + insertion_events_to_be_backfilled, + ) - if not extremities: + if not oldest_events_with_depth and not insertion_events_to_be_backfilled: logger.debug("Not backfilling as no extremeties found.") return False @@ -1089,10 +1185,12 @@ class FederationHandler(BaseHandler): # state *before* the event, ignoring the special casing certain event # types have. - forward_events = await self.store.get_successor_events(list(extremities)) + forward_event_ids = await self.store.get_successor_events( + list(oldest_events_with_depth) + ) extremities_events = await self.store.get_events( - forward_events, + forward_event_ids, redact_behaviour=EventRedactBehaviour.AS_IS, get_prev_content=False, ) @@ -1106,10 +1204,19 @@ class FederationHandler(BaseHandler): redact=False, check_history_visibility_only=True, ) + logger.debug( + "_maybe_backfill_inner: filtered_extremities %s", filtered_extremities + ) - if not filtered_extremities: + if not filtered_extremities and not insertion_events_to_be_backfilled: return False + extremities = { + **oldest_events_with_depth, + # TODO: insertion_events_to_be_backfilled is currently skipping the filtered_extremities checks + **insertion_events_to_be_backfilled, + } + # Check if we reached a point where we should start backfilling. sorted_extremeties_tuple = sorted(extremities.items(), key=lambda e: -int(e[1])) max_depth = sorted_extremeties_tuple[0][1] diff --git a/synapse/storage/database.py b/synapse/storage/database.py index c8015a3848..95d2caff62 100644 --- a/synapse/storage/database.py +++ b/synapse/storage/database.py @@ -941,13 +941,13 @@ class DatabasePool: `lock` should generally be set to True (the default), but can be set to False if either of the following are true: - - * there is a UNIQUE INDEX on the key columns. In this case a conflict - will cause an IntegrityError in which case this function will retry - the update. - - * we somehow know that we are the only thread which will be updating - this table. + 1. there is a UNIQUE INDEX on the key columns. In this case a conflict + will cause an IntegrityError in which case this function will retry + the update. + 2. we somehow know that we are the only thread which will be updating + this table. + As an additional note, this parameter only matters for old SQLite versions + because we will use native upserts otherwise. Args: table: The table to upsert into diff --git a/synapse/storage/databases/main/event_federation.py b/synapse/storage/databases/main/event_federation.py index 44018c1c31..bddf5ef192 100644 --- a/synapse/storage/databases/main/event_federation.py +++ b/synapse/storage/databases/main/event_federation.py @@ -671,28 +671,98 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, SQLBas # Return all events where not all sets can reach them. return {eid for eid, n in event_to_missing_sets.items() if n} - async def get_oldest_events_with_depth_in_room(self, room_id): + async def get_oldest_event_ids_with_depth_in_room(self, room_id) -> Dict[str, int]: + """Gets the oldest events(backwards extremities) in the room along with the + aproximate depth. + + We use this function so that we can compare and see if someones current + depth at their current scrollback is within pagination range of the + event extremeties. If the current depth is close to the depth of given + oldest event, we can trigger a backfill. + + Args: + room_id: Room where we want to find the oldest events + + Returns: + Map from event_id to depth + """ + + def get_oldest_event_ids_with_depth_in_room_txn(txn, room_id): + # Assemble a dictionary with event_id -> depth for the oldest events + # we know of in the room. Backwards extremeties are the oldest + # events we know of in the room but we only know of them because + # some other event referenced them by prev_event and aren't peristed + # in our database yet (meaning we don't know their depth + # specifically). So we need to look for the aproximate depth from + # the events connected to the current backwards extremeties. + sql = """ + SELECT b.event_id, MAX(e.depth) FROM events as e + /** + * Get the edge connections from the event_edges table + * so we can see whether this event's prev_events points + * to a backward extremity in the next join. + */ + INNER JOIN event_edges as g + ON g.event_id = e.event_id + /** + * We find the "oldest" events in the room by looking for + * events connected to backwards extremeties (oldest events + * in the room that we know of so far). + */ + INNER JOIN event_backward_extremities as b + ON g.prev_event_id = b.event_id + WHERE b.room_id = ? AND g.is_state is ? + GROUP BY b.event_id + """ + + txn.execute(sql, (room_id, False)) + + return dict(txn) + return await self.db_pool.runInteraction( - "get_oldest_events_with_depth_in_room", - self.get_oldest_events_with_depth_in_room_txn, + "get_oldest_event_ids_with_depth_in_room", + get_oldest_event_ids_with_depth_in_room_txn, room_id, ) - def get_oldest_events_with_depth_in_room_txn(self, txn, room_id): - sql = ( - "SELECT b.event_id, MAX(e.depth) FROM events as e" - " INNER JOIN event_edges as g" - " ON g.event_id = e.event_id" - " INNER JOIN event_backward_extremities as b" - " ON g.prev_event_id = b.event_id" - " WHERE b.room_id = ? AND g.is_state is ?" - " GROUP BY b.event_id" + async def get_insertion_event_backwards_extremities_in_room( + self, room_id + ) -> Dict[str, int]: + """Get the insertion events we know about that we haven't backfilled yet. + + We use this function so that we can compare and see if someones current + depth at their current scrollback is within pagination range of the + insertion event. If the current depth is close to the depth of given + insertion event, we can trigger a backfill. + + Args: + room_id: Room where we want to find the oldest events + + Returns: + Map from event_id to depth + """ + + def get_insertion_event_backwards_extremities_in_room_txn(txn, room_id): + sql = """ + SELECT b.event_id, MAX(e.depth) FROM insertion_events as i + /* We only want insertion events that are also marked as backwards extremities */ + INNER JOIN insertion_event_extremities as b USING (event_id) + /* Get the depth of the insertion event from the events table */ + INNER JOIN events AS e USING (event_id) + WHERE b.room_id = ? + GROUP BY b.event_id + """ + + txn.execute(sql, (room_id,)) + + return dict(txn) + + return await self.db_pool.runInteraction( + "get_insertion_event_backwards_extremities_in_room", + get_insertion_event_backwards_extremities_in_room_txn, + room_id, ) - txn.execute(sql, (room_id, False)) - - return dict(txn) - async def get_max_depth_of(self, event_ids: List[str]) -> Tuple[str, int]: """Returns the event ID and depth for the event that has the max depth from a set of event IDs @@ -1041,7 +1111,6 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, SQLBas if row[1] not in event_results: queue.put((-row[0], row[1])) - # Navigate up the DAG by prev_event txn.execute(query, (event_id, False, limit - len(event_results))) prev_event_id_results = txn.fetchall() logger.debug( @@ -1136,6 +1205,19 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, SQLBas _delete_old_forward_extrem_cache_txn, ) + async def insert_insertion_extremity(self, event_id: str, room_id: str) -> None: + await self.db_pool.simple_upsert( + table="insertion_event_extremities", + keyvalues={"event_id": event_id}, + values={ + "event_id": event_id, + "room_id": room_id, + }, + insertion_values={}, + desc="insert_insertion_extremity", + lock=False, + ) + async def insert_received_event_to_staging( self, origin: str, event: EventBase ) -> None: diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py index 86baf397fb..40b53274fb 100644 --- a/synapse/storage/databases/main/events.py +++ b/synapse/storage/databases/main/events.py @@ -1845,6 +1845,18 @@ class PersistEventsStore: }, ) + # When we receive an event with a `chunk_id` referencing the + # `next_chunk_id` of the insertion event, we can remove it from the + # `insertion_event_extremities` table. + sql = """ + DELETE FROM insertion_event_extremities WHERE event_id IN ( + SELECT event_id FROM insertion_events + WHERE next_chunk_id = ? + ) + """ + + txn.execute(sql, (chunk_id,)) + def _handle_redaction(self, txn, redacted_event_id): """Handles receiving a redaction and checking whether we need to remove any redacted relations from the database. @@ -2101,15 +2113,17 @@ class PersistEventsStore: Forward extremities are handled when we first start persisting the events. """ + # From the events passed in, add all of the prev events as backwards extremities. + # Ignore any events that are already backwards extrems or outliers. query = ( "INSERT INTO event_backward_extremities (event_id, room_id)" " SELECT ?, ? WHERE NOT EXISTS (" - " SELECT 1 FROM event_backward_extremities" - " WHERE event_id = ? AND room_id = ?" + " SELECT 1 FROM event_backward_extremities" + " WHERE event_id = ? AND room_id = ?" " )" " AND NOT EXISTS (" - " SELECT 1 FROM events WHERE event_id = ? AND room_id = ? " - " AND outlier = ?" + " SELECT 1 FROM events WHERE event_id = ? AND room_id = ? " + " AND outlier = ?" " )" ) @@ -2123,6 +2137,8 @@ class PersistEventsStore: ], ) + # Delete all these events that we've already fetched and now know that their + # prev events are the new backwards extremeties. query = ( "DELETE FROM event_backward_extremities" " WHERE event_id = ? AND room_id = ?" diff --git a/synapse/storage/schema/__init__.py b/synapse/storage/schema/__init__.py index 36340a652a..fd4dd67d91 100644 --- a/synapse/storage/schema/__init__.py +++ b/synapse/storage/schema/__init__.py @@ -12,7 +12,7 @@ # See the License for the specific language governing permissions and # limitations under the License. -SCHEMA_VERSION = 61 +SCHEMA_VERSION = 62 """Represents the expectations made by the codebase about the database schema This should be incremented whenever the codebase changes its requirements on the diff --git a/synapse/storage/schema/main/delta/62/01insertion_event_extremities.sql b/synapse/storage/schema/main/delta/62/01insertion_event_extremities.sql new file mode 100644 index 0000000000..b731ef284a --- /dev/null +++ b/synapse/storage/schema/main/delta/62/01insertion_event_extremities.sql @@ -0,0 +1,24 @@ +/* Copyright 2021 The Matrix.org Foundation C.I.C + * + * 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. + */ + + +-- Add a table that keeps track of which "insertion" events need to be backfilled +CREATE TABLE IF NOT EXISTS insertion_event_extremities( + event_id TEXT NOT NULL, + room_id TEXT NOT NULL +); + +CREATE UNIQUE INDEX IF NOT EXISTS insertion_event_extremities_event_id ON insertion_event_extremities(event_id); +CREATE INDEX IF NOT EXISTS insertion_event_extremities_room_id ON insertion_event_extremities(room_id);