|
- # Copyright 2014-2016 OpenMarket Ltd
- # Copyright 2018-2019 New Vector Ltd
- # Copyright 2019-2021 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.
- import itertools
- import logging
- from collections import OrderedDict
- from typing import (
- TYPE_CHECKING,
- Any,
- Collection,
- Dict,
- Generator,
- Iterable,
- List,
- Optional,
- Set,
- Tuple,
- cast,
- )
-
- import attr
- from prometheus_client import Counter
-
- import synapse.metrics
- from synapse.api.constants import EventContentFields, EventTypes, RelationTypes
- from synapse.api.errors import PartialStateConflictError
- from synapse.api.room_versions import RoomVersions
- from synapse.events import EventBase, relation_from_event
- from synapse.events.snapshot import EventContext
- from synapse.logging.opentracing import trace
- from synapse.storage._base import db_to_json, make_in_list_sql_clause
- from synapse.storage.database import (
- DatabasePool,
- LoggingDatabaseConnection,
- LoggingTransaction,
- )
- from synapse.storage.databases.main.events_worker import EventCacheEntry
- from synapse.storage.databases.main.search import SearchEntry
- from synapse.storage.engines import PostgresEngine
- from synapse.storage.util.id_generators import AbstractStreamIdGenerator
- from synapse.storage.util.sequence import SequenceGenerator
- from synapse.types import JsonDict, StateMap, StrCollection, get_domain_from_id
- from synapse.util import json_encoder
- from synapse.util.iterutils import batch_iter, sorted_topologically
- from synapse.util.stringutils import non_null_str_or_none
-
- if TYPE_CHECKING:
- from synapse.server import HomeServer
- from synapse.storage.databases.main import DataStore
-
-
- logger = logging.getLogger(__name__)
-
- persist_event_counter = Counter("synapse_storage_events_persisted_events", "")
- event_counter = Counter(
- "synapse_storage_events_persisted_events_sep",
- "",
- ["type", "origin_type", "origin_entity"],
- )
-
-
- @attr.s(slots=True, auto_attribs=True)
- class DeltaState:
- """Deltas to use to update the `current_state_events` table.
-
- Attributes:
- to_delete: List of type/state_keys to delete from current state
- to_insert: Map of state to upsert into current state
- no_longer_in_room: The server is not longer in the room, so the room
- should e.g. be removed from `current_state_events` table.
- """
-
- to_delete: List[Tuple[str, str]]
- to_insert: StateMap[str]
- no_longer_in_room: bool = False
-
-
- class PersistEventsStore:
- """Contains all the functions for writing events to the database.
-
- Should only be instantiated on one process (when using a worker mode setup).
-
- Note: This is not part of the `DataStore` mixin.
- """
-
- def __init__(
- self,
- hs: "HomeServer",
- db: DatabasePool,
- main_data_store: "DataStore",
- db_conn: LoggingDatabaseConnection,
- ):
- self.hs = hs
- self.db_pool = db
- self.store = main_data_store
- self.database_engine = db.engine
- self._clock = hs.get_clock()
- self._instance_name = hs.get_instance_name()
-
- self._ephemeral_messages_enabled = hs.config.server.enable_ephemeral_messages
- self.is_mine_id = hs.is_mine_id
-
- # This should only exist on instances that are configured to write
- assert (
- hs.get_instance_name() in hs.config.worker.writers.events
- ), "Can only instantiate EventsStore on master"
-
- # Since we have been configured to write, we ought to have id generators,
- # rather than id trackers.
- assert isinstance(self.store._backfill_id_gen, AbstractStreamIdGenerator)
- assert isinstance(self.store._stream_id_gen, AbstractStreamIdGenerator)
-
- # Ideally we'd move these ID gens here, unfortunately some other ID
- # generators are chained off them so doing so is a bit of a PITA.
- self._backfill_id_gen: AbstractStreamIdGenerator = self.store._backfill_id_gen
- self._stream_id_gen: AbstractStreamIdGenerator = self.store._stream_id_gen
-
- @trace
- async def _persist_events_and_state_updates(
- self,
- events_and_contexts: List[Tuple[EventBase, EventContext]],
- *,
- state_delta_for_room: Dict[str, DeltaState],
- new_forward_extremities: Dict[str, Set[str]],
- use_negative_stream_ordering: bool = False,
- inhibit_local_membership_updates: bool = False,
- ) -> None:
- """Persist a set of events alongside updates to the current state and
- forward extremities tables.
-
- Args:
- events_and_contexts:
- state_delta_for_room: Map from room_id to the delta to apply to
- room state
- new_forward_extremities: Map from room_id to set of event IDs
- that are the new forward extremities of the room.
- use_negative_stream_ordering: Whether to start stream_ordering on
- the negative side and decrement. This should be set as True
- for backfilled events because backfilled events get a negative
- stream ordering so they don't come down incremental `/sync`.
- inhibit_local_membership_updates: Stop the local_current_membership
- from being updated by these events. This should be set to True
- for backfilled events because backfilled events in the past do
- not affect the current local state.
-
- Returns:
- Resolves when the events have been persisted
-
- Raises:
- PartialStateConflictError: if attempting to persist a partial state event in
- a room that has been un-partial stated.
- """
-
- # We want to calculate the stream orderings as late as possible, as
- # we only notify after all events with a lesser stream ordering have
- # been persisted. I.e. if we spend 10s inside the with block then
- # that will delay all subsequent events from being notified about.
- # Hence why we do it down here rather than wrapping the entire
- # function.
- #
- # Its safe to do this after calculating the state deltas etc as we
- # only need to protect the *persistence* of the events. This is to
- # ensure that queries of the form "fetch events since X" don't
- # return events and stream positions after events that are still in
- # flight, as otherwise subsequent requests "fetch event since Y"
- # will not return those events.
- #
- # Note: Multiple instances of this function cannot be in flight at
- # the same time for the same room.
- if use_negative_stream_ordering:
- stream_ordering_manager = self._backfill_id_gen.get_next_mult(
- len(events_and_contexts)
- )
- else:
- stream_ordering_manager = self._stream_id_gen.get_next_mult(
- len(events_and_contexts)
- )
-
- async with stream_ordering_manager as stream_orderings:
- for (event, _), stream in zip(events_and_contexts, stream_orderings):
- event.internal_metadata.stream_ordering = stream
-
- await self.db_pool.runInteraction(
- "persist_events",
- self._persist_events_txn,
- events_and_contexts=events_and_contexts,
- inhibit_local_membership_updates=inhibit_local_membership_updates,
- state_delta_for_room=state_delta_for_room,
- new_forward_extremities=new_forward_extremities,
- )
- persist_event_counter.inc(len(events_and_contexts))
-
- if not use_negative_stream_ordering:
- # we don't want to set the event_persisted_position to a negative
- # stream_ordering.
- synapse.metrics.event_persisted_position.set(stream)
-
- for event, context in events_and_contexts:
- if context.app_service:
- origin_type = "local"
- origin_entity = context.app_service.id
- elif self.hs.is_mine_id(event.sender):
- origin_type = "local"
- origin_entity = "*client*"
- else:
- origin_type = "remote"
- origin_entity = get_domain_from_id(event.sender)
-
- event_counter.labels(event.type, origin_type, origin_entity).inc()
-
- for room_id, latest_event_ids in new_forward_extremities.items():
- self.store.get_latest_event_ids_in_room.prefill(
- (room_id,), list(latest_event_ids)
- )
-
- async def _get_events_which_are_prevs(self, event_ids: Iterable[str]) -> List[str]:
- """Filter the supplied list of event_ids to get those which are prev_events of
- existing (non-outlier/rejected) events.
-
- Args:
- event_ids: event ids to filter
-
- Returns:
- Filtered event ids
- """
- results: List[str] = []
-
- def _get_events_which_are_prevs_txn(
- txn: LoggingTransaction, batch: Collection[str]
- ) -> None:
- sql = """
- SELECT prev_event_id, internal_metadata
- FROM event_edges
- INNER JOIN events USING (event_id)
- LEFT JOIN rejections USING (event_id)
- LEFT JOIN event_json USING (event_id)
- WHERE
- NOT events.outlier
- AND rejections.event_id IS NULL
- AND
- """
-
- clause, args = make_in_list_sql_clause(
- self.database_engine, "prev_event_id", batch
- )
-
- txn.execute(sql + clause, args)
- results.extend(r[0] for r in txn if not db_to_json(r[1]).get("soft_failed"))
-
- for chunk in batch_iter(event_ids, 100):
- await self.db_pool.runInteraction(
- "_get_events_which_are_prevs", _get_events_which_are_prevs_txn, chunk
- )
-
- return results
-
- async def _get_prevs_before_rejected(self, event_ids: Iterable[str]) -> Set[str]:
- """Get soft-failed ancestors to remove from the extremities.
-
- Given a set of events, find all those that have been soft-failed or
- rejected. Returns those soft failed/rejected events and their prev
- events (whether soft-failed/rejected or not), and recurses up the
- prev-event graph until it finds no more soft-failed/rejected events.
-
- This is used to find extremities that are ancestors of new events, but
- are separated by soft failed events.
-
- Args:
- event_ids: Events to find prev events for. Note that these must have
- already been persisted.
-
- Returns:
- The previous events.
- """
-
- # The set of event_ids to return. This includes all soft-failed events
- # and their prev events.
- existing_prevs: Set[str] = set()
-
- def _get_prevs_before_rejected_txn(
- txn: LoggingTransaction, batch: Collection[str]
- ) -> None:
- to_recursively_check = batch
-
- while to_recursively_check:
- sql = """
- SELECT
- event_id, prev_event_id, internal_metadata,
- rejections.event_id IS NOT NULL
- FROM event_edges
- INNER JOIN events USING (event_id)
- LEFT JOIN rejections USING (event_id)
- LEFT JOIN event_json USING (event_id)
- WHERE
- NOT events.outlier
- AND
- """
-
- clause, args = make_in_list_sql_clause(
- self.database_engine, "event_id", to_recursively_check
- )
-
- txn.execute(sql + clause, args)
- to_recursively_check = []
-
- for _, prev_event_id, metadata, rejected in txn:
- if prev_event_id in existing_prevs:
- continue
-
- soft_failed = db_to_json(metadata).get("soft_failed")
- if soft_failed or rejected:
- to_recursively_check.append(prev_event_id)
- existing_prevs.add(prev_event_id)
-
- for chunk in batch_iter(event_ids, 100):
- await self.db_pool.runInteraction(
- "_get_prevs_before_rejected", _get_prevs_before_rejected_txn, chunk
- )
-
- return existing_prevs
-
- def _persist_events_txn(
- self,
- txn: LoggingTransaction,
- *,
- events_and_contexts: List[Tuple[EventBase, EventContext]],
- inhibit_local_membership_updates: bool,
- state_delta_for_room: Dict[str, DeltaState],
- new_forward_extremities: Dict[str, Set[str]],
- ) -> None:
- """Insert some number of room events into the necessary database tables.
-
- Rejected events are only inserted into the events table, the events_json table,
- and the rejections table. Things reading from those table will need to check
- whether the event was rejected.
-
- Args:
- txn
- events_and_contexts: events to persist
- inhibit_local_membership_updates: Stop the local_current_membership
- from being updated by these events. This should be set to True
- for backfilled events because backfilled events in the past do
- not affect the current local state.
- delete_existing True to purge existing table rows for the events
- from the database. This is useful when retrying due to
- IntegrityError.
- state_delta_for_room: The current-state delta for each room.
- new_forward_extremities: The new forward extremities for each room.
- For each room, a list of the event ids which are the forward
- extremities.
-
- Raises:
- PartialStateConflictError: if attempting to persist a partial state event in
- a room that has been un-partial stated.
- """
- all_events_and_contexts = events_and_contexts
-
- min_stream_order = events_and_contexts[0][0].internal_metadata.stream_ordering
- max_stream_order = events_and_contexts[-1][0].internal_metadata.stream_ordering
-
- # We check that the room still exists for events we're trying to
- # persist. This is to protect against races with deleting a room.
- #
- # Annoyingly SQLite doesn't support row level locking.
- if isinstance(self.database_engine, PostgresEngine):
- for room_id in {e.room_id for e, _ in events_and_contexts}:
- txn.execute(
- "SELECT room_version FROM rooms WHERE room_id = ? FOR SHARE",
- (room_id,),
- )
- row = txn.fetchone()
- if row is None:
- raise Exception(f"Room does not exist {room_id}")
-
- # stream orderings should have been assigned by now
- assert min_stream_order
- assert max_stream_order
-
- # Once the txn completes, invalidate all of the relevant caches. Note that we do this
- # up here because it captures all the events_and_contexts before any are removed.
- for event, _ in events_and_contexts:
- self.store.invalidate_get_event_cache_after_txn(txn, event.event_id)
- if event.redacts:
- self.store.invalidate_get_event_cache_after_txn(txn, event.redacts)
-
- relates_to = None
- relation = relation_from_event(event)
- if relation:
- relates_to = relation.parent_id
-
- assert event.internal_metadata.stream_ordering is not None
- txn.call_after(
- self.store._invalidate_caches_for_event,
- event.internal_metadata.stream_ordering,
- event.event_id,
- event.room_id,
- event.type,
- getattr(event, "state_key", None),
- event.redacts,
- relates_to,
- backfilled=False,
- )
-
- # Ensure that we don't have the same event twice.
- events_and_contexts = self._filter_events_and_contexts_for_duplicates(
- events_and_contexts
- )
-
- self._update_room_depths_txn(txn, events_and_contexts=events_and_contexts)
-
- # _update_outliers_txn filters out any events which have already been
- # persisted, and returns the filtered list.
- events_and_contexts = self._update_outliers_txn(
- txn, events_and_contexts=events_and_contexts
- )
-
- # From this point onwards the events are only events that we haven't
- # seen before.
-
- self._store_event_txn(txn, events_and_contexts=events_and_contexts)
-
- self._update_forward_extremities_txn(
- txn,
- new_forward_extremities=new_forward_extremities,
- max_stream_order=max_stream_order,
- )
-
- self._persist_transaction_ids_txn(txn, events_and_contexts)
-
- # Insert into event_to_state_groups.
- self._store_event_state_mappings_txn(txn, events_and_contexts)
-
- self._persist_event_auth_chain_txn(txn, [e for e, _ in events_and_contexts])
-
- # _store_rejected_events_txn filters out any events which were
- # rejected, and returns the filtered list.
- events_and_contexts = self._store_rejected_events_txn(
- txn, events_and_contexts=events_and_contexts
- )
-
- # From this point onwards the events are only ones that weren't
- # rejected.
-
- self._update_metadata_tables_txn(
- txn,
- events_and_contexts=events_and_contexts,
- all_events_and_contexts=all_events_and_contexts,
- inhibit_local_membership_updates=inhibit_local_membership_updates,
- )
-
- # We call this last as it assumes we've inserted the events into
- # room_memberships, where applicable.
- # NB: This function invalidates all state related caches
- self._update_current_state_txn(txn, state_delta_for_room, min_stream_order)
-
- def _persist_event_auth_chain_txn(
- self,
- txn: LoggingTransaction,
- events: List[EventBase],
- ) -> None:
- # We only care about state events, so this if there are no state events.
- if not any(e.is_state() for e in events):
- return
-
- # We want to store event_auth mappings for rejected events, as they're
- # used in state res v2.
- # This is only necessary if the rejected event appears in an accepted
- # event's auth chain, but its easier for now just to store them (and
- # it doesn't take much storage compared to storing the entire event
- # anyway).
- self.db_pool.simple_insert_many_txn(
- txn,
- table="event_auth",
- keys=("event_id", "room_id", "auth_id"),
- values=[
- (event.event_id, event.room_id, auth_id)
- for event in events
- for auth_id in event.auth_event_ids()
- if event.is_state()
- ],
- )
-
- # We now calculate chain ID/sequence numbers for any state events we're
- # persisting. We ignore out of band memberships as we're not in the room
- # and won't have their auth chain (we'll fix it up later if we join the
- # room).
- #
- # See: docs/auth_chain_difference_algorithm.md
-
- # We ignore legacy rooms that we aren't filling the chain cover index
- # for.
- rows = self.db_pool.simple_select_many_txn(
- txn,
- table="rooms",
- column="room_id",
- iterable={event.room_id for event in events if event.is_state()},
- keyvalues={},
- retcols=("room_id", "has_auth_chain_index"),
- )
- rooms_using_chain_index = {
- row["room_id"] for row in rows if row["has_auth_chain_index"]
- }
-
- state_events = {
- event.event_id: event
- for event in events
- if event.is_state() and event.room_id in rooms_using_chain_index
- }
-
- if not state_events:
- return
-
- # We need to know the type/state_key and auth events of the events we're
- # calculating chain IDs for. We don't rely on having the full Event
- # instances as we'll potentially be pulling more events from the DB and
- # we don't need the overhead of fetching/parsing the full event JSON.
- event_to_types = {
- e.event_id: (e.type, e.state_key) for e in state_events.values()
- }
- event_to_auth_chain = {
- e.event_id: e.auth_event_ids() for e in state_events.values()
- }
- event_to_room_id = {e.event_id: e.room_id for e in state_events.values()}
-
- self._add_chain_cover_index(
- txn,
- self.db_pool,
- self.store.event_chain_id_gen,
- event_to_room_id,
- event_to_types,
- event_to_auth_chain,
- )
-
- @classmethod
- def _add_chain_cover_index(
- cls,
- txn: LoggingTransaction,
- db_pool: DatabasePool,
- event_chain_id_gen: SequenceGenerator,
- event_to_room_id: Dict[str, str],
- event_to_types: Dict[str, Tuple[str, str]],
- event_to_auth_chain: Dict[str, StrCollection],
- ) -> None:
- """Calculate the chain cover index for the given events.
-
- Args:
- event_to_room_id: Event ID to the room ID of the event
- event_to_types: Event ID to type and state_key of the event
- event_to_auth_chain: Event ID to list of auth event IDs of the
- event (events with no auth events can be excluded).
- """
-
- # Map from event ID to chain ID/sequence number.
- chain_map: Dict[str, Tuple[int, int]] = {}
-
- # Set of event IDs to calculate chain ID/seq numbers for.
- events_to_calc_chain_id_for = set(event_to_room_id)
-
- # We check if there are any events that need to be handled in the rooms
- # we're looking at. These should just be out of band memberships, where
- # we didn't have the auth chain when we first persisted.
- rows = db_pool.simple_select_many_txn(
- txn,
- table="event_auth_chain_to_calculate",
- keyvalues={},
- column="room_id",
- iterable=set(event_to_room_id.values()),
- retcols=("event_id", "type", "state_key"),
- )
- for row in rows:
- event_id = row["event_id"]
- event_type = row["type"]
- state_key = row["state_key"]
-
- # (We could pull out the auth events for all rows at once using
- # simple_select_many, but this case happens rarely and almost always
- # with a single row.)
- auth_events = db_pool.simple_select_onecol_txn(
- txn,
- "event_auth",
- keyvalues={"event_id": event_id},
- retcol="auth_id",
- )
-
- events_to_calc_chain_id_for.add(event_id)
- event_to_types[event_id] = (event_type, state_key)
- event_to_auth_chain[event_id] = auth_events
-
- # First we get the chain ID and sequence numbers for the events'
- # auth events (that aren't also currently being persisted).
- #
- # Note that there there is an edge case here where we might not have
- # calculated chains and sequence numbers for events that were "out
- # of band". We handle this case by fetching the necessary info and
- # adding it to the set of events to calculate chain IDs for.
-
- missing_auth_chains = {
- a_id
- for auth_events in event_to_auth_chain.values()
- for a_id in auth_events
- if a_id not in events_to_calc_chain_id_for
- }
-
- # We loop here in case we find an out of band membership and need to
- # fetch their auth event info.
- while missing_auth_chains:
- sql = """
- SELECT event_id, events.type, se.state_key, chain_id, sequence_number
- FROM events
- INNER JOIN state_events AS se USING (event_id)
- LEFT JOIN event_auth_chains USING (event_id)
- WHERE
- """
- clause, args = make_in_list_sql_clause(
- txn.database_engine,
- "event_id",
- missing_auth_chains,
- )
- txn.execute(sql + clause, args)
-
- missing_auth_chains.clear()
-
- for (
- auth_id,
- event_type,
- state_key,
- chain_id,
- sequence_number,
- ) in txn.fetchall():
- event_to_types[auth_id] = (event_type, state_key)
-
- if chain_id is None:
- # No chain ID, so the event was persisted out of band.
- # We add to list of events to calculate auth chains for.
-
- events_to_calc_chain_id_for.add(auth_id)
-
- event_to_auth_chain[auth_id] = db_pool.simple_select_onecol_txn(
- txn,
- "event_auth",
- keyvalues={"event_id": auth_id},
- retcol="auth_id",
- )
-
- missing_auth_chains.update(
- e
- for e in event_to_auth_chain[auth_id]
- if e not in event_to_types
- )
- else:
- chain_map[auth_id] = (chain_id, sequence_number)
-
- # Now we check if we have any events where we don't have auth chain,
- # this should only be out of band memberships.
- for event_id in sorted_topologically(event_to_auth_chain, event_to_auth_chain):
- for auth_id in event_to_auth_chain[event_id]:
- if (
- auth_id not in chain_map
- and auth_id not in events_to_calc_chain_id_for
- ):
- events_to_calc_chain_id_for.discard(event_id)
-
- # If this is an event we're trying to persist we add it to
- # the list of events to calculate chain IDs for next time
- # around. (Otherwise we will have already added it to the
- # table).
- room_id = event_to_room_id.get(event_id)
- if room_id:
- e_type, state_key = event_to_types[event_id]
- db_pool.simple_insert_txn(
- txn,
- table="event_auth_chain_to_calculate",
- values={
- "event_id": event_id,
- "room_id": room_id,
- "type": e_type,
- "state_key": state_key,
- },
- )
-
- # We stop checking the event's auth events since we've
- # discarded it.
- break
-
- if not events_to_calc_chain_id_for:
- return
-
- # Allocate chain ID/sequence numbers to each new event.
- new_chain_tuples = cls._allocate_chain_ids(
- txn,
- db_pool,
- event_chain_id_gen,
- event_to_room_id,
- event_to_types,
- event_to_auth_chain,
- events_to_calc_chain_id_for,
- chain_map,
- )
- chain_map.update(new_chain_tuples)
-
- db_pool.simple_insert_many_txn(
- txn,
- table="event_auth_chains",
- keys=("event_id", "chain_id", "sequence_number"),
- values=[
- (event_id, c_id, seq)
- for event_id, (c_id, seq) in new_chain_tuples.items()
- ],
- )
-
- db_pool.simple_delete_many_txn(
- txn,
- table="event_auth_chain_to_calculate",
- keyvalues={},
- column="event_id",
- values=new_chain_tuples,
- )
-
- # Now we need to calculate any new links between chains caused by
- # the new events.
- #
- # Links are pairs of chain ID/sequence numbers such that for any
- # event A (CA, SA) and any event B (CB, SB), B is in A's auth chain
- # if and only if there is at least one link (CA, S1) -> (CB, S2)
- # where SA >= S1 and S2 >= SB.
- #
- # We try and avoid adding redundant links to the table, e.g. if we
- # have two links between two chains which both start/end at the
- # sequence number event (or cross) then one can be safely dropped.
- #
- # To calculate new links we look at every new event and:
- # 1. Fetch the chain ID/sequence numbers of its auth events,
- # discarding any that are reachable by other auth events, or
- # that have the same chain ID as the event.
- # 2. For each retained auth event we:
- # a. Add a link from the event's to the auth event's chain
- # ID/sequence number; and
- # b. Add a link from the event to every chain reachable by the
- # auth event.
-
- # Step 1, fetch all existing links from all the chains we've seen
- # referenced.
- chain_links = _LinkMap()
- rows = db_pool.simple_select_many_txn(
- txn,
- table="event_auth_chain_links",
- column="origin_chain_id",
- iterable={chain_id for chain_id, _ in chain_map.values()},
- keyvalues={},
- retcols=(
- "origin_chain_id",
- "origin_sequence_number",
- "target_chain_id",
- "target_sequence_number",
- ),
- )
- for row in rows:
- chain_links.add_link(
- (row["origin_chain_id"], row["origin_sequence_number"]),
- (row["target_chain_id"], row["target_sequence_number"]),
- new=False,
- )
-
- # We do this in toplogical order to avoid adding redundant links.
- for event_id in sorted_topologically(
- events_to_calc_chain_id_for, event_to_auth_chain
- ):
- chain_id, sequence_number = chain_map[event_id]
-
- # Filter out auth events that are reachable by other auth
- # events. We do this by looking at every permutation of pairs of
- # auth events (A, B) to check if B is reachable from A.
- reduction = {
- a_id
- for a_id in event_to_auth_chain.get(event_id, [])
- if chain_map[a_id][0] != chain_id
- }
- for start_auth_id, end_auth_id in itertools.permutations(
- event_to_auth_chain.get(event_id, []),
- r=2,
- ):
- if chain_links.exists_path_from(
- chain_map[start_auth_id], chain_map[end_auth_id]
- ):
- reduction.discard(end_auth_id)
-
- # Step 2, figure out what the new links are from the reduced
- # list of auth events.
- for auth_id in reduction:
- auth_chain_id, auth_sequence_number = chain_map[auth_id]
-
- # Step 2a, add link between the event and auth event
- chain_links.add_link(
- (chain_id, sequence_number), (auth_chain_id, auth_sequence_number)
- )
-
- # Step 2b, add a link to chains reachable from the auth
- # event.
- for target_id, target_seq in chain_links.get_links_from(
- (auth_chain_id, auth_sequence_number)
- ):
- if target_id == chain_id:
- continue
-
- chain_links.add_link(
- (chain_id, sequence_number), (target_id, target_seq)
- )
-
- db_pool.simple_insert_many_txn(
- txn,
- table="event_auth_chain_links",
- keys=(
- "origin_chain_id",
- "origin_sequence_number",
- "target_chain_id",
- "target_sequence_number",
- ),
- values=[
- (source_id, source_seq, target_id, target_seq)
- for (
- source_id,
- source_seq,
- target_id,
- target_seq,
- ) in chain_links.get_additions()
- ],
- )
-
- @staticmethod
- def _allocate_chain_ids(
- txn: LoggingTransaction,
- db_pool: DatabasePool,
- event_chain_id_gen: SequenceGenerator,
- event_to_room_id: Dict[str, str],
- event_to_types: Dict[str, Tuple[str, str]],
- event_to_auth_chain: Dict[str, StrCollection],
- events_to_calc_chain_id_for: Set[str],
- chain_map: Dict[str, Tuple[int, int]],
- ) -> Dict[str, Tuple[int, int]]:
- """Allocates, but does not persist, chain ID/sequence numbers for the
- events in `events_to_calc_chain_id_for`. (c.f. _add_chain_cover_index
- for info on args)
- """
-
- # We now calculate the chain IDs/sequence numbers for the events. We do
- # this by looking at the chain ID and sequence number of any auth event
- # with the same type/state_key and incrementing the sequence number by
- # one. If there was no match or the chain ID/sequence number is already
- # taken we generate a new chain.
- #
- # We try to reduce the number of times that we hit the database by
- # batching up calls, to make this more efficient when persisting large
- # numbers of state events (e.g. during joins).
- #
- # We do this by:
- # 1. Calculating for each event which auth event will be used to
- # inherit the chain ID, i.e. converting the auth chain graph to a
- # tree that we can allocate chains on. We also keep track of which
- # existing chain IDs have been referenced.
- # 2. Fetching the max allocated sequence number for each referenced
- # existing chain ID, generating a map from chain ID to the max
- # allocated sequence number.
- # 3. Iterating over the tree and allocating a chain ID/seq no. to the
- # new event, by incrementing the sequence number from the
- # referenced event's chain ID/seq no. and checking that the
- # incremented sequence number hasn't already been allocated (by
- # looking in the map generated in the previous step). We generate a
- # new chain if the sequence number has already been allocated.
- #
-
- existing_chains: Set[int] = set()
- tree: List[Tuple[str, Optional[str]]] = []
-
- # We need to do this in a topologically sorted order as we want to
- # generate chain IDs/sequence numbers of an event's auth events before
- # the event itself.
- for event_id in sorted_topologically(
- events_to_calc_chain_id_for, event_to_auth_chain
- ):
- for auth_id in event_to_auth_chain.get(event_id, []):
- if event_to_types.get(event_id) == event_to_types.get(auth_id):
- existing_chain_id = chain_map.get(auth_id)
- if existing_chain_id:
- existing_chains.add(existing_chain_id[0])
-
- tree.append((event_id, auth_id))
- break
- else:
- tree.append((event_id, None))
-
- # Fetch the current max sequence number for each existing referenced chain.
- sql = """
- SELECT chain_id, MAX(sequence_number) FROM event_auth_chains
- WHERE %s
- GROUP BY chain_id
- """
- clause, args = make_in_list_sql_clause(
- db_pool.engine, "chain_id", existing_chains
- )
- txn.execute(sql % (clause,), args)
-
- chain_to_max_seq_no: Dict[Any, int] = {row[0]: row[1] for row in txn}
-
- # Allocate the new events chain ID/sequence numbers.
- #
- # To reduce the number of calls to the database we don't allocate a
- # chain ID number in the loop, instead we use a temporary `object()` for
- # each new chain ID. Once we've done the loop we generate the necessary
- # number of new chain IDs in one call, replacing all temporary
- # objects with real allocated chain IDs.
-
- unallocated_chain_ids: Set[object] = set()
- new_chain_tuples: Dict[str, Tuple[Any, int]] = {}
- for event_id, auth_event_id in tree:
- # If we reference an auth_event_id we fetch the allocated chain ID,
- # either from the existing `chain_map` or the newly generated
- # `new_chain_tuples` map.
- existing_chain_id = None
- if auth_event_id:
- existing_chain_id = new_chain_tuples.get(auth_event_id)
- if not existing_chain_id:
- existing_chain_id = chain_map[auth_event_id]
-
- new_chain_tuple: Optional[Tuple[Any, int]] = None
- if existing_chain_id:
- # We found a chain ID/sequence number candidate, check its
- # not already taken.
- proposed_new_id = existing_chain_id[0]
- proposed_new_seq = existing_chain_id[1] + 1
-
- if chain_to_max_seq_no[proposed_new_id] < proposed_new_seq:
- new_chain_tuple = (
- proposed_new_id,
- proposed_new_seq,
- )
-
- # If we need to start a new chain we allocate a temporary chain ID.
- if not new_chain_tuple:
- new_chain_tuple = (object(), 1)
- unallocated_chain_ids.add(new_chain_tuple[0])
-
- new_chain_tuples[event_id] = new_chain_tuple
- chain_to_max_seq_no[new_chain_tuple[0]] = new_chain_tuple[1]
-
- # Generate new chain IDs for all unallocated chain IDs.
- newly_allocated_chain_ids = event_chain_id_gen.get_next_mult_txn(
- txn, len(unallocated_chain_ids)
- )
-
- # Map from potentially temporary chain ID to real chain ID
- chain_id_to_allocated_map: Dict[Any, int] = dict(
- zip(unallocated_chain_ids, newly_allocated_chain_ids)
- )
- chain_id_to_allocated_map.update((c, c) for c in existing_chains)
-
- return {
- event_id: (chain_id_to_allocated_map[chain_id], seq)
- for event_id, (chain_id, seq) in new_chain_tuples.items()
- }
-
- def _persist_transaction_ids_txn(
- self,
- txn: LoggingTransaction,
- events_and_contexts: List[Tuple[EventBase, EventContext]],
- ) -> None:
- """Persist the mapping from transaction IDs to event IDs (if defined)."""
-
- inserted_ts = self._clock.time_msec()
- to_insert_token_id: List[Tuple[str, str, str, int, str, int]] = []
- to_insert_device_id: List[Tuple[str, str, str, str, str, int]] = []
- for event, _ in events_and_contexts:
- txn_id = getattr(event.internal_metadata, "txn_id", None)
- token_id = getattr(event.internal_metadata, "token_id", None)
- device_id = getattr(event.internal_metadata, "device_id", None)
-
- if txn_id is not None:
- if token_id is not None:
- to_insert_token_id.append(
- (
- event.event_id,
- event.room_id,
- event.sender,
- token_id,
- txn_id,
- inserted_ts,
- )
- )
-
- if device_id is not None:
- to_insert_device_id.append(
- (
- event.event_id,
- event.room_id,
- event.sender,
- device_id,
- txn_id,
- inserted_ts,
- )
- )
-
- # Synapse usually relies on the device_id to scope transactions for events,
- # except for users without device IDs (appservice, guests, and access
- # tokens minted with the admin API) which use the access token ID instead.
- #
- # TODO https://github.com/matrix-org/synapse/issues/16042
- if to_insert_token_id:
- self.db_pool.simple_insert_many_txn(
- txn,
- table="event_txn_id",
- keys=(
- "event_id",
- "room_id",
- "user_id",
- "token_id",
- "txn_id",
- "inserted_ts",
- ),
- values=to_insert_token_id,
- )
-
- if to_insert_device_id:
- self.db_pool.simple_insert_many_txn(
- txn,
- table="event_txn_id_device_id",
- keys=(
- "event_id",
- "room_id",
- "user_id",
- "device_id",
- "txn_id",
- "inserted_ts",
- ),
- values=to_insert_device_id,
- )
-
- async def update_current_state(
- self,
- room_id: str,
- state_delta: DeltaState,
- ) -> None:
- """Update the current state stored in the datatabase for the given room"""
-
- async with self._stream_id_gen.get_next() as stream_ordering:
- await self.db_pool.runInteraction(
- "update_current_state",
- self._update_current_state_txn,
- state_delta_by_room={room_id: state_delta},
- stream_id=stream_ordering,
- )
-
- def _update_current_state_txn(
- self,
- txn: LoggingTransaction,
- state_delta_by_room: Dict[str, DeltaState],
- stream_id: int,
- ) -> None:
- for room_id, delta_state in state_delta_by_room.items():
- to_delete = delta_state.to_delete
- to_insert = delta_state.to_insert
-
- # Figure out the changes of membership to invalidate the
- # `get_rooms_for_user` cache.
- # We find out which membership events we may have deleted
- # and which we have added, then we invalidate the caches for all
- # those users.
- members_changed = {
- state_key
- for ev_type, state_key in itertools.chain(to_delete, to_insert)
- if ev_type == EventTypes.Member
- }
-
- if delta_state.no_longer_in_room:
- # Server is no longer in the room so we delete the room from
- # current_state_events, being careful we've already updated the
- # rooms.room_version column (which gets populated in a
- # background task).
- self._upsert_room_version_txn(txn, room_id)
-
- # Before deleting we populate the current_state_delta_stream
- # so that async background tasks get told what happened.
- sql = """
- INSERT INTO current_state_delta_stream
- (stream_id, instance_name, room_id, type, state_key, event_id, prev_event_id)
- SELECT ?, ?, room_id, type, state_key, null, event_id
- FROM current_state_events
- WHERE room_id = ?
- """
- txn.execute(sql, (stream_id, self._instance_name, room_id))
-
- # We also want to invalidate the membership caches for users
- # that were in the room.
- users_in_room = self.store.get_users_in_room_txn(txn, room_id)
- members_changed.update(users_in_room)
-
- self.db_pool.simple_delete_txn(
- txn,
- table="current_state_events",
- keyvalues={"room_id": room_id},
- )
- else:
- # We're still in the room, so we update the current state as normal.
-
- # First we add entries to the current_state_delta_stream. We
- # do this before updating the current_state_events table so
- # that we can use it to calculate the `prev_event_id`. (This
- # allows us to not have to pull out the existing state
- # unnecessarily).
- #
- # The stream_id for the update is chosen to be the minimum of the stream_ids
- # for the batch of the events that we are persisting; that means we do not
- # end up in a situation where workers see events before the
- # current_state_delta updates.
- #
- sql = """
- INSERT INTO current_state_delta_stream
- (stream_id, instance_name, room_id, type, state_key, event_id, prev_event_id)
- SELECT ?, ?, ?, ?, ?, ?, (
- SELECT event_id FROM current_state_events
- WHERE room_id = ? AND type = ? AND state_key = ?
- )
- """
- txn.execute_batch(
- sql,
- (
- (
- stream_id,
- self._instance_name,
- room_id,
- etype,
- state_key,
- to_insert.get((etype, state_key)),
- room_id,
- etype,
- state_key,
- )
- for etype, state_key in itertools.chain(to_delete, to_insert)
- ),
- )
- # Now we actually update the current_state_events table
-
- txn.execute_batch(
- "DELETE FROM current_state_events"
- " WHERE room_id = ? AND type = ? AND state_key = ?",
- (
- (room_id, etype, state_key)
- for etype, state_key in itertools.chain(to_delete, to_insert)
- ),
- )
-
- # We include the membership in the current state table, hence we do
- # a lookup when we insert. This assumes that all events have already
- # been inserted into room_memberships.
- txn.execute_batch(
- """INSERT INTO current_state_events
- (room_id, type, state_key, event_id, membership, event_stream_ordering)
- VALUES (
- ?, ?, ?, ?,
- (SELECT membership FROM room_memberships WHERE event_id = ?),
- (SELECT stream_ordering FROM events WHERE event_id = ?)
- )
- """,
- [
- (room_id, key[0], key[1], ev_id, ev_id, ev_id)
- for key, ev_id in to_insert.items()
- ],
- )
-
- # We now update `local_current_membership`. We do this regardless
- # of whether we're still in the room or not to handle the case where
- # e.g. we just got banned (where we need to record that fact here).
-
- # Note: Do we really want to delete rows here (that we do not
- # subsequently reinsert below)? While technically correct it means
- # we have no record of the fact the user *was* a member of the
- # room but got, say, state reset out of it.
- if to_delete or to_insert:
- txn.execute_batch(
- "DELETE FROM local_current_membership"
- " WHERE room_id = ? AND user_id = ?",
- (
- (room_id, state_key)
- for etype, state_key in itertools.chain(to_delete, to_insert)
- if etype == EventTypes.Member and self.is_mine_id(state_key)
- ),
- )
-
- if to_insert:
- txn.execute_batch(
- """INSERT INTO local_current_membership
- (room_id, user_id, event_id, membership, event_stream_ordering)
- VALUES (
- ?, ?, ?,
- (SELECT membership FROM room_memberships WHERE event_id = ?),
- (SELECT stream_ordering FROM events WHERE event_id = ?)
- )
- """,
- [
- (room_id, key[1], ev_id, ev_id, ev_id)
- for key, ev_id in to_insert.items()
- if key[0] == EventTypes.Member and self.is_mine_id(key[1])
- ],
- )
-
- txn.call_after(
- self.store._curr_state_delta_stream_cache.entity_has_changed,
- room_id,
- stream_id,
- )
-
- # Invalidate the various caches
- self.store._invalidate_state_caches_and_stream(
- txn, room_id, members_changed
- )
-
- # Check if any of the remote membership changes requires us to
- # unsubscribe from their device lists.
- self.store.handle_potentially_left_users_txn(
- txn, {m for m in members_changed if not self.hs.is_mine_id(m)}
- )
-
- def _upsert_room_version_txn(self, txn: LoggingTransaction, room_id: str) -> None:
- """Update the room version in the database based off current state
- events.
-
- This is used when we're about to delete current state and we want to
- ensure that the `rooms.room_version` column is up to date.
- """
-
- sql = """
- SELECT json FROM event_json
- INNER JOIN current_state_events USING (room_id, event_id)
- WHERE room_id = ? AND type = ? AND state_key = ?
- """
- txn.execute(sql, (room_id, EventTypes.Create, ""))
- row = txn.fetchone()
- if row:
- event_json = db_to_json(row[0])
- content = event_json.get("content", {})
- creator = content.get("creator")
- room_version_id = content.get("room_version", RoomVersions.V1.identifier)
-
- self.db_pool.simple_upsert_txn(
- txn,
- table="rooms",
- keyvalues={"room_id": room_id},
- values={"room_version": room_version_id},
- insertion_values={"is_public": False, "creator": creator},
- )
-
- def _update_forward_extremities_txn(
- self,
- txn: LoggingTransaction,
- new_forward_extremities: Dict[str, Set[str]],
- max_stream_order: int,
- ) -> None:
- for room_id in new_forward_extremities.keys():
- self.db_pool.simple_delete_txn(
- txn, table="event_forward_extremities", keyvalues={"room_id": room_id}
- )
-
- self.db_pool.simple_insert_many_txn(
- txn,
- table="event_forward_extremities",
- keys=("event_id", "room_id"),
- values=[
- (ev_id, room_id)
- for room_id, new_extrem in new_forward_extremities.items()
- for ev_id in new_extrem
- ],
- )
- # We now insert into stream_ordering_to_exterm a mapping from room_id,
- # new stream_ordering to new forward extremeties in the room.
- # This allows us to later efficiently look up the forward extremeties
- # for a room before a given stream_ordering
- self.db_pool.simple_insert_many_txn(
- txn,
- table="stream_ordering_to_exterm",
- keys=("room_id", "event_id", "stream_ordering"),
- values=[
- (room_id, event_id, max_stream_order)
- for room_id, new_extrem in new_forward_extremities.items()
- for event_id in new_extrem
- ],
- )
-
- @classmethod
- def _filter_events_and_contexts_for_duplicates(
- cls, events_and_contexts: List[Tuple[EventBase, EventContext]]
- ) -> List[Tuple[EventBase, EventContext]]:
- """Ensure that we don't have the same event twice.
-
- Pick the earliest non-outlier if there is one, else the earliest one.
-
- Args:
- events_and_contexts:
-
- Returns:
- filtered list
- """
- new_events_and_contexts: OrderedDict[
- str, Tuple[EventBase, EventContext]
- ] = OrderedDict()
- for event, context in events_and_contexts:
- prev_event_context = new_events_and_contexts.get(event.event_id)
- if prev_event_context:
- if not event.internal_metadata.is_outlier():
- if prev_event_context[0].internal_metadata.is_outlier():
- # To ensure correct ordering we pop, as OrderedDict is
- # ordered by first insertion.
- new_events_and_contexts.pop(event.event_id, None)
- new_events_and_contexts[event.event_id] = (event, context)
- else:
- new_events_and_contexts[event.event_id] = (event, context)
- return list(new_events_and_contexts.values())
-
- def _update_room_depths_txn(
- self,
- txn: LoggingTransaction,
- events_and_contexts: List[Tuple[EventBase, EventContext]],
- ) -> None:
- """Update min_depth for each room
-
- Args:
- txn: db connection
- events_and_contexts: events we are persisting
- """
- depth_updates: Dict[str, int] = {}
- for event, context in events_and_contexts:
- # Then update the `stream_ordering` position to mark the latest
- # event as the front of the room. This should not be done for
- # backfilled events because backfilled events have negative
- # stream_ordering and happened in the past so we know that we don't
- # need to update the stream_ordering tip/front for the room.
- assert event.internal_metadata.stream_ordering is not None
- if event.internal_metadata.stream_ordering >= 0:
- txn.call_after(
- self.store._events_stream_cache.entity_has_changed,
- event.room_id,
- event.internal_metadata.stream_ordering,
- )
-
- if not event.internal_metadata.is_outlier() and not context.rejected:
- depth_updates[event.room_id] = max(
- event.depth, depth_updates.get(event.room_id, event.depth)
- )
-
- for room_id, depth in depth_updates.items():
- self._update_min_depth_for_room_txn(txn, room_id, depth)
-
- def _update_outliers_txn(
- self,
- txn: LoggingTransaction,
- events_and_contexts: List[Tuple[EventBase, EventContext]],
- ) -> List[Tuple[EventBase, EventContext]]:
- """Update any outliers with new event info.
-
- This turns outliers into ex-outliers (unless the new event was rejected), and
- also removes any other events we have already seen from the list.
-
- Args:
- txn: db connection
- events_and_contexts: events we are persisting
-
- Returns:
- new list, without events which are already in the events table.
-
- Raises:
- PartialStateConflictError: if attempting to persist a partial state event in
- a room that has been un-partial stated.
- """
- txn.execute(
- "SELECT event_id, outlier FROM events WHERE event_id in (%s)"
- % (",".join(["?"] * len(events_and_contexts)),),
- [event.event_id for event, _ in events_and_contexts],
- )
-
- have_persisted = dict(cast(Iterable[Tuple[str, bool]], txn))
-
- logger.debug(
- "_update_outliers_txn: events=%s have_persisted=%s",
- [ev.event_id for ev, _ in events_and_contexts],
- have_persisted,
- )
-
- to_remove = set()
- for event, context in events_and_contexts:
- outlier_persisted = have_persisted.get(event.event_id)
- logger.debug(
- "_update_outliers_txn: event=%s outlier=%s outlier_persisted=%s",
- event.event_id,
- event.internal_metadata.is_outlier(),
- outlier_persisted,
- )
-
- # Ignore events which we haven't persisted at all
- if outlier_persisted is None:
- continue
-
- to_remove.add(event)
-
- if context.rejected:
- # If the incoming event is rejected then we don't care if the event
- # was an outlier or not - what we have is at least as good.
- continue
-
- if not event.internal_metadata.is_outlier() and outlier_persisted:
- # We received a copy of an event that we had already stored as
- # an outlier in the database. We now have some state at that event
- # so we need to update the state_groups table with that state.
- #
- # Note that we do not update the stream_ordering of the event in this
- # scenario. XXX: does this cause bugs? It will mean we won't send such
- # events down /sync. In general they will be historical events, so that
- # doesn't matter too much, but that is not always the case.
-
- logger.info(
- "_update_outliers_txn: Updating state for ex-outlier event %s",
- event.event_id,
- )
-
- # insert into event_to_state_groups.
- try:
- self._store_event_state_mappings_txn(txn, ((event, context),))
- except Exception:
- logger.exception("")
- raise
-
- # Add an entry to the ex_outlier_stream table to replicate the
- # change in outlier status to our workers.
- stream_order = event.internal_metadata.stream_ordering
- state_group_id = context.state_group
- self.db_pool.simple_insert_txn(
- txn,
- table="ex_outlier_stream",
- values={
- "event_stream_ordering": stream_order,
- "event_id": event.event_id,
- "state_group": state_group_id,
- "instance_name": self._instance_name,
- },
- )
-
- sql = "UPDATE events SET outlier = FALSE WHERE event_id = ?"
- txn.execute(sql, (event.event_id,))
-
- # Update the event_backward_extremities table now that this
- # event isn't an outlier any more.
- self._update_backward_extremeties(txn, [event])
-
- return [ec for ec in events_and_contexts if ec[0] not in to_remove]
-
- def _store_event_txn(
- self,
- txn: LoggingTransaction,
- events_and_contexts: Collection[Tuple[EventBase, EventContext]],
- ) -> None:
- """Insert new events into the event, event_json, redaction and
- state_events tables.
- """
-
- if not events_and_contexts:
- # nothing to do here
- return
-
- def event_dict(event: EventBase) -> JsonDict:
- d = event.get_dict()
- d.pop("redacted", None)
- d.pop("redacted_because", None)
- return d
-
- self.db_pool.simple_insert_many_txn(
- txn,
- table="event_json",
- keys=("event_id", "room_id", "internal_metadata", "json", "format_version"),
- values=(
- (
- event.event_id,
- event.room_id,
- json_encoder.encode(event.internal_metadata.get_dict()),
- json_encoder.encode(event_dict(event)),
- event.format_version,
- )
- for event, _ in events_and_contexts
- ),
- )
-
- self.db_pool.simple_insert_many_txn(
- txn,
- table="events",
- keys=(
- "instance_name",
- "stream_ordering",
- "topological_ordering",
- "depth",
- "event_id",
- "room_id",
- "type",
- "processed",
- "outlier",
- "origin_server_ts",
- "received_ts",
- "sender",
- "contains_url",
- "state_key",
- "rejection_reason",
- ),
- values=(
- (
- self._instance_name,
- event.internal_metadata.stream_ordering,
- event.depth, # topological_ordering
- event.depth, # depth
- event.event_id,
- event.room_id,
- event.type,
- True, # processed
- event.internal_metadata.is_outlier(),
- int(event.origin_server_ts),
- self._clock.time_msec(),
- event.sender,
- "url" in event.content and isinstance(event.content["url"], str),
- event.get_state_key(),
- context.rejected,
- )
- for event, context in events_and_contexts
- ),
- )
-
- # If we're persisting an unredacted event we go and ensure
- # that we mark any redactions that reference this event as
- # requiring censoring.
- unredacted_events = [
- event.event_id
- for event, _ in events_and_contexts
- if not event.internal_metadata.is_redacted()
- ]
- sql = "UPDATE redactions SET have_censored = FALSE WHERE "
- clause, args = make_in_list_sql_clause(
- self.database_engine,
- "redacts",
- unredacted_events,
- )
- txn.execute(sql + clause, args)
-
- self.db_pool.simple_insert_many_txn(
- txn,
- table="state_events",
- keys=("event_id", "room_id", "type", "state_key"),
- values=(
- (event.event_id, event.room_id, event.type, event.state_key)
- for event, _ in events_and_contexts
- if event.is_state()
- ),
- )
-
- def _store_rejected_events_txn(
- self,
- txn: LoggingTransaction,
- events_and_contexts: List[Tuple[EventBase, EventContext]],
- ) -> List[Tuple[EventBase, EventContext]]:
- """Add rows to the 'rejections' table for received events which were
- rejected
-
- Args:
- txn: db connection
- events_and_contexts: events we are persisting
-
- Returns:
- new list, without the rejected events.
- """
- # Remove the rejected events from the list now that we've added them
- # to the events table and the events_json table.
- to_remove = set()
- for event, context in events_and_contexts:
- if context.rejected:
- # Insert the event_id into the rejections table
- # (events.rejection_reason has already been done)
- self._store_rejections_txn(txn, event.event_id, context.rejected)
- to_remove.add(event)
-
- return [ec for ec in events_and_contexts if ec[0] not in to_remove]
-
- def _update_metadata_tables_txn(
- self,
- txn: LoggingTransaction,
- *,
- events_and_contexts: List[Tuple[EventBase, EventContext]],
- all_events_and_contexts: List[Tuple[EventBase, EventContext]],
- inhibit_local_membership_updates: bool = False,
- ) -> None:
- """Update all the miscellaneous tables for new events
-
- Args:
- txn: db connection
- events_and_contexts: events we are persisting
- all_events_and_contexts: all events that we were going to persist.
- This includes events we've already persisted, etc, that wouldn't
- appear in events_and_context.
- inhibit_local_membership_updates: Stop the local_current_membership
- from being updated by these events. This should be set to True
- for backfilled events because backfilled events in the past do
- not affect the current local state.
- """
-
- # Insert all the push actions into the event_push_actions table.
- self._set_push_actions_for_event_and_users_txn(
- txn,
- events_and_contexts=events_and_contexts,
- all_events_and_contexts=all_events_and_contexts,
- )
-
- if not events_and_contexts:
- # nothing to do here
- return
-
- for event, _ in events_and_contexts:
- if event.type == EventTypes.Redaction and event.redacts is not None:
- # Remove the entries in the event_push_actions table for the
- # redacted event.
- self._remove_push_actions_for_event_id_txn(
- txn, event.room_id, event.redacts
- )
-
- # Remove from relations table.
- self._handle_redact_relations(txn, event.room_id, event.redacts)
-
- # Update the event_forward_extremities, event_backward_extremities and
- # event_edges tables.
- self._handle_mult_prev_events(
- txn, events=[event for event, _ in events_and_contexts]
- )
-
- for event, _ in events_and_contexts:
- if event.type == EventTypes.Name:
- # Insert into the event_search table.
- self._store_room_name_txn(txn, event)
- elif event.type == EventTypes.Topic:
- # Insert into the event_search table.
- self._store_room_topic_txn(txn, event)
- elif event.type == EventTypes.Message:
- # Insert into the event_search table.
- self._store_room_message_txn(txn, event)
- elif event.type == EventTypes.Redaction and event.redacts is not None:
- # Insert into the redactions table.
- self._store_redaction(txn, event)
- elif event.type == EventTypes.Retention:
- # Update the room_retention table.
- self._store_retention_policy_for_room_txn(txn, event)
-
- self._handle_event_relations(txn, event)
-
- # Store the labels for this event.
- labels = event.content.get(EventContentFields.LABELS)
- if labels:
- self.insert_labels_for_event_txn(
- txn, event.event_id, labels, event.room_id, event.depth
- )
-
- if self._ephemeral_messages_enabled:
- # If there's an expiry timestamp on the event, store it.
- expiry_ts = event.content.get(EventContentFields.SELF_DESTRUCT_AFTER)
- if type(expiry_ts) is int and not event.is_state(): # noqa: E721
- self._insert_event_expiry_txn(txn, event.event_id, expiry_ts)
-
- # Insert into the room_memberships table.
- self._store_room_members_txn(
- txn,
- [
- event
- for event, _ in events_and_contexts
- if event.type == EventTypes.Member
- ],
- inhibit_local_membership_updates=inhibit_local_membership_updates,
- )
-
- # Prefill the event cache
- self._add_to_cache(txn, events_and_contexts)
-
- def _add_to_cache(
- self,
- txn: LoggingTransaction,
- events_and_contexts: List[Tuple[EventBase, EventContext]],
- ) -> None:
- to_prefill = []
-
- rows = []
-
- ev_map = {e.event_id: e for e, _ in events_and_contexts}
- if not ev_map:
- return
-
- sql = (
- "SELECT "
- " e.event_id as event_id, "
- " r.redacts as redacts,"
- " rej.event_id as rejects "
- " FROM events as e"
- " LEFT JOIN rejections as rej USING (event_id)"
- " LEFT JOIN redactions as r ON e.event_id = r.redacts"
- " WHERE "
- )
-
- clause, args = make_in_list_sql_clause(
- self.database_engine, "e.event_id", list(ev_map)
- )
-
- txn.execute(sql + clause, args)
- rows = self.db_pool.cursor_to_dict(txn)
- for row in rows:
- event = ev_map[row["event_id"]]
- if not row["rejects"] and not row["redacts"]:
- to_prefill.append(EventCacheEntry(event=event, redacted_event=None))
-
- async def external_prefill() -> None:
- for cache_entry in to_prefill:
- await self.store._get_event_cache.set_external(
- (cache_entry.event.event_id,), cache_entry
- )
-
- def local_prefill() -> None:
- for cache_entry in to_prefill:
- self.store._get_event_cache.set_local(
- (cache_entry.event.event_id,), cache_entry
- )
-
- # The order these are called here is not as important as knowing that after the
- # transaction is finished, the async_call_after will run before the call_after.
- txn.async_call_after(external_prefill)
- txn.call_after(local_prefill)
-
- def _store_redaction(self, txn: LoggingTransaction, event: EventBase) -> None:
- assert event.redacts is not None
- self.db_pool.simple_upsert_txn(
- txn,
- table="redactions",
- keyvalues={"event_id": event.event_id},
- values={
- "redacts": event.redacts,
- "received_ts": self._clock.time_msec(),
- },
- )
-
- def insert_labels_for_event_txn(
- self,
- txn: LoggingTransaction,
- event_id: str,
- labels: List[str],
- room_id: str,
- topological_ordering: int,
- ) -> None:
- """Store the mapping between an event's ID and its labels, with one row per
- (event_id, label) tuple.
-
- Args:
- txn: The transaction to execute.
- event_id: The event's ID.
- labels: A list of text labels.
- room_id: The ID of the room the event was sent to.
- topological_ordering: The position of the event in the room's topology.
- """
- self.db_pool.simple_insert_many_txn(
- txn=txn,
- table="event_labels",
- keys=("event_id", "label", "room_id", "topological_ordering"),
- values=[
- (event_id, label, room_id, topological_ordering) for label in labels
- ],
- )
-
- def _insert_event_expiry_txn(
- self, txn: LoggingTransaction, event_id: str, expiry_ts: int
- ) -> None:
- """Save the expiry timestamp associated with a given event ID.
-
- Args:
- txn: The database transaction to use.
- event_id: The event ID the expiry timestamp is associated with.
- expiry_ts: The timestamp at which to expire (delete) the event.
- """
- self.db_pool.simple_insert_txn(
- txn=txn,
- table="event_expiry",
- values={"event_id": event_id, "expiry_ts": expiry_ts},
- )
-
- def _store_room_members_txn(
- self,
- txn: LoggingTransaction,
- events: List[EventBase],
- *,
- inhibit_local_membership_updates: bool = False,
- ) -> None:
- """
- Store a room member in the database.
-
- Args:
- txn: The transaction to use.
- events: List of events to store.
- inhibit_local_membership_updates: Stop the local_current_membership
- from being updated by these events. This should be set to True
- for backfilled events because backfilled events in the past do
- not affect the current local state.
- """
-
- self.db_pool.simple_insert_many_txn(
- txn,
- table="room_memberships",
- keys=(
- "event_id",
- "event_stream_ordering",
- "user_id",
- "sender",
- "room_id",
- "membership",
- "display_name",
- "avatar_url",
- ),
- values=[
- (
- event.event_id,
- event.internal_metadata.stream_ordering,
- event.state_key,
- event.user_id,
- event.room_id,
- event.membership,
- non_null_str_or_none(event.content.get("displayname")),
- non_null_str_or_none(event.content.get("avatar_url")),
- )
- for event in events
- ],
- )
-
- for event in events:
- assert event.internal_metadata.stream_ordering is not None
-
- # We update the local_current_membership table only if the event is
- # "current", i.e., its something that has just happened.
- #
- # This will usually get updated by the `current_state_events` handling,
- # unless its an outlier, and an outlier is only "current" if it's an "out of
- # band membership", like a remote invite or a rejection of a remote invite.
- if (
- self.is_mine_id(event.state_key)
- and not inhibit_local_membership_updates
- and event.internal_metadata.is_outlier()
- and event.internal_metadata.is_out_of_band_membership()
- ):
- self.db_pool.simple_upsert_txn(
- txn,
- table="local_current_membership",
- keyvalues={"room_id": event.room_id, "user_id": event.state_key},
- values={
- "event_id": event.event_id,
- "event_stream_ordering": event.internal_metadata.stream_ordering,
- "membership": event.membership,
- },
- )
-
- def _handle_event_relations(
- self, txn: LoggingTransaction, event: EventBase
- ) -> None:
- """Handles inserting relation data during persistence of events
-
- Args:
- txn: The current database transaction.
- event: The event which might have relations.
- """
- relation = relation_from_event(event)
- if not relation:
- # No relation, nothing to do.
- return
-
- self.db_pool.simple_insert_txn(
- txn,
- table="event_relations",
- values={
- "event_id": event.event_id,
- "relates_to_id": relation.parent_id,
- "relation_type": relation.rel_type,
- "aggregation_key": relation.aggregation_key,
- },
- )
-
- if relation.rel_type == RelationTypes.THREAD:
- # Upsert into the threads table, but only overwrite the value if the
- # new event is of a later topological order OR if the topological
- # ordering is equal, but the stream ordering is later.
- sql = """
- INSERT INTO threads (room_id, thread_id, latest_event_id, topological_ordering, stream_ordering)
- VALUES (?, ?, ?, ?, ?)
- ON CONFLICT (room_id, thread_id)
- DO UPDATE SET
- latest_event_id = excluded.latest_event_id,
- topological_ordering = excluded.topological_ordering,
- stream_ordering = excluded.stream_ordering
- WHERE
- threads.topological_ordering <= excluded.topological_ordering AND
- threads.stream_ordering < excluded.stream_ordering
- """
-
- txn.execute(
- sql,
- (
- event.room_id,
- relation.parent_id,
- event.event_id,
- event.depth,
- event.internal_metadata.stream_ordering,
- ),
- )
-
- def _handle_redact_relations(
- self, txn: LoggingTransaction, room_id: str, redacted_event_id: str
- ) -> None:
- """Handles receiving a redaction and checking whether the redacted event
- has any relations which must be removed from the database.
-
- Args:
- txn
- room_id: The room ID of the event that was redacted.
- redacted_event_id: The event that was redacted.
- """
-
- # Fetch the relation of the event being redacted.
- row = self.db_pool.simple_select_one_txn(
- txn,
- table="event_relations",
- keyvalues={"event_id": redacted_event_id},
- retcols=("relates_to_id", "relation_type"),
- allow_none=True,
- )
- # Nothing to do if no relation is found.
- if row is None:
- return
-
- redacted_relates_to = row["relates_to_id"]
- rel_type = row["relation_type"]
- self.db_pool.simple_delete_txn(
- txn, table="event_relations", keyvalues={"event_id": redacted_event_id}
- )
-
- # Any relation information for the related event must be cleared.
- self.store._invalidate_cache_and_stream(
- txn, self.store.get_relations_for_event, (redacted_relates_to,)
- )
- if rel_type == RelationTypes.REFERENCE:
- self.store._invalidate_cache_and_stream(
- txn, self.store.get_references_for_event, (redacted_relates_to,)
- )
- if rel_type == RelationTypes.REPLACE:
- self.store._invalidate_cache_and_stream(
- txn, self.store.get_applicable_edit, (redacted_relates_to,)
- )
- if rel_type == RelationTypes.THREAD:
- self.store._invalidate_cache_and_stream(
- txn, self.store.get_thread_summary, (redacted_relates_to,)
- )
- self.store._invalidate_cache_and_stream(
- txn, self.store.get_thread_participated, (redacted_relates_to,)
- )
- self.store._invalidate_cache_and_stream(
- txn, self.store.get_threads, (room_id,)
- )
-
- # Find the new latest event in the thread.
- sql = """
- SELECT event_id, topological_ordering, stream_ordering
- FROM event_relations
- INNER JOIN events USING (event_id)
- WHERE relates_to_id = ? AND relation_type = ?
- ORDER BY topological_ordering DESC, stream_ordering DESC
- LIMIT 1
- """
- txn.execute(sql, (redacted_relates_to, RelationTypes.THREAD))
-
- # If a latest event is found, update the threads table, this might
- # be the same current latest event (if an earlier event in the thread
- # was redacted).
- latest_event_row = txn.fetchone()
- if latest_event_row:
- self.db_pool.simple_upsert_txn(
- txn,
- table="threads",
- keyvalues={"room_id": room_id, "thread_id": redacted_relates_to},
- values={
- "latest_event_id": latest_event_row[0],
- "topological_ordering": latest_event_row[1],
- "stream_ordering": latest_event_row[2],
- },
- )
-
- # Otherwise, delete the thread: it no longer exists.
- else:
- self.db_pool.simple_delete_one_txn(
- txn, table="threads", keyvalues={"thread_id": redacted_relates_to}
- )
-
- def _store_room_topic_txn(self, txn: LoggingTransaction, event: EventBase) -> None:
- if isinstance(event.content.get("topic"), str):
- self.store_event_search_txn(
- txn, event, "content.topic", event.content["topic"]
- )
-
- def _store_room_name_txn(self, txn: LoggingTransaction, event: EventBase) -> None:
- if isinstance(event.content.get("name"), str):
- self.store_event_search_txn(
- txn, event, "content.name", event.content["name"]
- )
-
- def _store_room_message_txn(
- self, txn: LoggingTransaction, event: EventBase
- ) -> None:
- if isinstance(event.content.get("body"), str):
- self.store_event_search_txn(
- txn, event, "content.body", event.content["body"]
- )
-
- def _store_retention_policy_for_room_txn(
- self, txn: LoggingTransaction, event: EventBase
- ) -> None:
- if not event.is_state():
- logger.debug("Ignoring non-state m.room.retention event")
- return
-
- if hasattr(event, "content") and (
- "min_lifetime" in event.content or "max_lifetime" in event.content
- ):
- if (
- "min_lifetime" in event.content
- and type(event.content["min_lifetime"]) is not int # noqa: E721
- ) or (
- "max_lifetime" in event.content
- and type(event.content["max_lifetime"]) is not int # noqa: E721
- ):
- # Ignore the event if one of the value isn't an integer.
- return
-
- self.db_pool.simple_insert_txn(
- txn=txn,
- table="room_retention",
- values={
- "room_id": event.room_id,
- "event_id": event.event_id,
- "min_lifetime": event.content.get("min_lifetime"),
- "max_lifetime": event.content.get("max_lifetime"),
- },
- )
-
- self.store._invalidate_cache_and_stream(
- txn, self.store.get_retention_policy_for_room, (event.room_id,)
- )
-
- def store_event_search_txn(
- self, txn: LoggingTransaction, event: EventBase, key: str, value: str
- ) -> None:
- """Add event to the search table
-
- Args:
- txn: The database transaction.
- event: The event being added to the search table.
- key: A key describing the search value (one of "content.name",
- "content.topic", or "content.body")
- value: The value from the event's content.
- """
- self.store.store_search_entries_txn(
- txn,
- (
- SearchEntry(
- key=key,
- value=value,
- event_id=event.event_id,
- room_id=event.room_id,
- stream_ordering=event.internal_metadata.stream_ordering,
- origin_server_ts=event.origin_server_ts,
- ),
- ),
- )
-
- def _set_push_actions_for_event_and_users_txn(
- self,
- txn: LoggingTransaction,
- events_and_contexts: List[Tuple[EventBase, EventContext]],
- all_events_and_contexts: List[Tuple[EventBase, EventContext]],
- ) -> None:
- """Handles moving push actions from staging table to main
- event_push_actions table for all events in `events_and_contexts`.
-
- Also ensures that all events in `all_events_and_contexts` are removed
- from the push action staging area.
-
- Args:
- events_and_contexts: events we are persisting
- all_events_and_contexts: all events that we were going to persist.
- This includes events we've already persisted, etc, that wouldn't
- appear in events_and_context.
- """
-
- # Only notifiable events will have push actions associated with them,
- # so let's filter them out. (This makes joining large rooms faster, as
- # these queries took seconds to process all the state events).
- notifiable_events = [
- event
- for event, _ in events_and_contexts
- if event.internal_metadata.is_notifiable()
- ]
-
- sql = """
- INSERT INTO event_push_actions (
- room_id, event_id, user_id, actions, stream_ordering,
- topological_ordering, notif, highlight, unread, thread_id
- )
- SELECT ?, event_id, user_id, actions, ?, ?, notif, highlight, unread, thread_id
- FROM event_push_actions_staging
- WHERE event_id = ?
- """
-
- if notifiable_events:
- txn.execute_batch(
- sql,
- (
- (
- event.room_id,
- event.internal_metadata.stream_ordering,
- event.depth,
- event.event_id,
- )
- for event in notifiable_events
- ),
- )
-
- # Now we delete the staging area for *all* events that were being
- # persisted.
- txn.execute_batch(
- "DELETE FROM event_push_actions_staging WHERE event_id = ?",
- (
- (event.event_id,)
- for event, _ in all_events_and_contexts
- if event.internal_metadata.is_notifiable()
- ),
- )
-
- def _remove_push_actions_for_event_id_txn(
- self, txn: LoggingTransaction, room_id: str, event_id: str
- ) -> None:
- txn.execute(
- "DELETE FROM event_push_actions WHERE room_id = ? AND event_id = ?",
- (room_id, event_id),
- )
-
- def _store_rejections_txn(
- self, txn: LoggingTransaction, event_id: str, reason: str
- ) -> None:
- self.db_pool.simple_insert_txn(
- txn,
- table="rejections",
- values={
- "event_id": event_id,
- "reason": reason,
- "last_check": self._clock.time_msec(),
- },
- )
-
- def _store_event_state_mappings_txn(
- self,
- txn: LoggingTransaction,
- events_and_contexts: Collection[Tuple[EventBase, EventContext]],
- ) -> None:
- """
- Raises:
- PartialStateConflictError: if attempting to persist a partial state event in
- a room that has been un-partial stated.
- """
- state_groups = {}
- for event, context in events_and_contexts:
- if event.internal_metadata.is_outlier():
- # double-check that we don't have any events that claim to be outliers
- # *and* have partial state (which is meaningless: we should have no
- # state at all for an outlier)
- if context.partial_state:
- raise ValueError(
- "Outlier event %s claims to have partial state", event.event_id
- )
-
- continue
-
- # if the event was rejected, just give it the same state as its
- # predecessor.
- if context.rejected:
- state_groups[event.event_id] = context.state_group_before_event
- continue
-
- state_groups[event.event_id] = context.state_group
-
- # if we have partial state for these events, record the fact. (This happens
- # here rather than in _store_event_txn because it also needs to happen when
- # we de-outlier an event.)
- try:
- self.db_pool.simple_insert_many_txn(
- txn,
- table="partial_state_events",
- keys=("room_id", "event_id"),
- values=[
- (
- event.room_id,
- event.event_id,
- )
- for event, ctx in events_and_contexts
- if ctx.partial_state
- ],
- )
- except self.db_pool.engine.module.IntegrityError:
- logger.info(
- "Cannot persist events %s in rooms %s: room has been un-partial stated",
- [
- event.event_id
- for event, ctx in events_and_contexts
- if ctx.partial_state
- ],
- list(
- {
- event.room_id
- for event, ctx in events_and_contexts
- if ctx.partial_state
- }
- ),
- )
- raise PartialStateConflictError()
-
- self.db_pool.simple_upsert_many_txn(
- txn,
- table="event_to_state_groups",
- key_names=["event_id"],
- key_values=[[event_id] for event_id, _ in state_groups.items()],
- value_names=["state_group"],
- value_values=[
- [state_group_id] for _, state_group_id in state_groups.items()
- ],
- )
-
- for event_id, state_group_id in state_groups.items():
- txn.call_after(
- self.store._get_state_group_for_event.prefill,
- (event_id,),
- state_group_id,
- )
-
- def _update_min_depth_for_room_txn(
- self, txn: LoggingTransaction, room_id: str, depth: int
- ) -> None:
- min_depth = self.store._get_min_depth_interaction(txn, room_id)
-
- if min_depth is not None and depth >= min_depth:
- return
-
- self.db_pool.simple_upsert_txn(
- txn,
- table="room_depth",
- keyvalues={"room_id": room_id},
- values={"min_depth": depth},
- )
-
- def _handle_mult_prev_events(
- self, txn: LoggingTransaction, events: List[EventBase]
- ) -> None:
- """
- For the given event, update the event edges table and forward and
- backward extremities tables.
- """
- self.db_pool.simple_insert_many_txn(
- txn,
- table="event_edges",
- keys=("event_id", "prev_event_id"),
- values=[
- (ev.event_id, e_id) for ev in events for e_id in ev.prev_event_ids()
- ],
- )
-
- self._update_backward_extremeties(txn, events)
-
- def _update_backward_extremeties(
- self, txn: LoggingTransaction, events: List[EventBase]
- ) -> None:
- """Updates the event_backward_extremities tables based on the new/updated
- events being persisted.
-
- This is called for new events *and* for events that were outliers, but
- are now being persisted as non-outliers.
-
- 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 = ?"
- " )"
- # 1. Don't add an event as a extremity again if we already persisted it
- # as a non-outlier.
- # 2. Don't add an outlier as an extremity if it has no prev_events
- " AND NOT EXISTS ("
- " SELECT 1 FROM events"
- " LEFT JOIN event_edges edge"
- " ON edge.event_id = events.event_id"
- " WHERE events.event_id = ? AND events.room_id = ? AND (events.outlier = FALSE OR edge.event_id IS NULL)"
- " )"
- )
-
- txn.execute_batch(
- query,
- [
- (e_id, ev.room_id, e_id, ev.room_id, e_id, ev.room_id)
- for ev in events
- for e_id in ev.prev_event_ids()
- if not ev.internal_metadata.is_outlier()
- ],
- )
-
- # 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 = ?"
- )
- backward_extremity_tuples_to_remove = [
- (ev.event_id, ev.room_id)
- for ev in events
- if not ev.internal_metadata.is_outlier()
- # If we encountered an event with no prev_events, then we might
- # as well remove it now because it won't ever have anything else
- # to backfill from.
- or len(ev.prev_event_ids()) == 0
- ]
- txn.execute_batch(
- query,
- backward_extremity_tuples_to_remove,
- )
-
- # Clear out the failed backfill attempts after we successfully pulled
- # the event. Since we no longer need these events as backward
- # extremities, it also means that they won't be backfilled from again so
- # we no longer need to store the backfill attempts around it.
- query = """
- DELETE FROM event_failed_pull_attempts
- WHERE event_id = ? and room_id = ?
- """
- txn.execute_batch(
- query,
- backward_extremity_tuples_to_remove,
- )
-
-
- @attr.s(slots=True, auto_attribs=True)
- class _LinkMap:
- """A helper type for tracking links between chains."""
-
- # Stores the set of links as nested maps: source chain ID -> target chain ID
- # -> source sequence number -> target sequence number.
- maps: Dict[int, Dict[int, Dict[int, int]]] = attr.Factory(dict)
-
- # Stores the links that have been added (with new set to true), as tuples of
- # `(source chain ID, source sequence no, target chain ID, target sequence no.)`
- additions: Set[Tuple[int, int, int, int]] = attr.Factory(set)
-
- def add_link(
- self,
- src_tuple: Tuple[int, int],
- target_tuple: Tuple[int, int],
- new: bool = True,
- ) -> bool:
- """Add a new link between two chains, ensuring no redundant links are added.
-
- New links should be added in topological order.
-
- Args:
- src_tuple: The chain ID/sequence number of the source of the link.
- target_tuple: The chain ID/sequence number of the target of the link.
- new: Whether this is a "new" link, i.e. should it be returned
- by `get_additions`.
-
- Returns:
- True if a link was added, false if the given link was dropped as redundant
- """
- src_chain, src_seq = src_tuple
- target_chain, target_seq = target_tuple
-
- current_links = self.maps.setdefault(src_chain, {}).setdefault(target_chain, {})
-
- assert src_chain != target_chain
-
- if new:
- # Check if the new link is redundant
- for current_seq_src, current_seq_target in current_links.items():
- # If a link "crosses" another link then its redundant. For example
- # in the following link 1 (L1) is redundant, as any event reachable
- # via L1 is *also* reachable via L2.
- #
- # Chain A Chain B
- # | |
- # L1 |------ |
- # | | |
- # L2 |---- | -->|
- # | | |
- # | |--->|
- # | |
- # | |
- #
- # So we only need to keep links which *do not* cross, i.e. links
- # that both start and end above or below an existing link.
- #
- # Note, since we add links in topological ordering we should never
- # see `src_seq` less than `current_seq_src`.
-
- if current_seq_src <= src_seq and target_seq <= current_seq_target:
- # This new link is redundant, nothing to do.
- return False
-
- self.additions.add((src_chain, src_seq, target_chain, target_seq))
-
- current_links[src_seq] = target_seq
- return True
-
- def get_links_from(
- self, src_tuple: Tuple[int, int]
- ) -> Generator[Tuple[int, int], None, None]:
- """Gets the chains reachable from the given chain/sequence number.
-
- Yields:
- The chain ID and sequence number the link points to.
- """
- src_chain, src_seq = src_tuple
- for target_id, sequence_numbers in self.maps.get(src_chain, {}).items():
- for link_src_seq, target_seq in sequence_numbers.items():
- if link_src_seq <= src_seq:
- yield target_id, target_seq
-
- def get_links_between(
- self, source_chain: int, target_chain: int
- ) -> Generator[Tuple[int, int], None, None]:
- """Gets the links between two chains.
-
- Yields:
- The source and target sequence numbers.
- """
-
- yield from self.maps.get(source_chain, {}).get(target_chain, {}).items()
-
- def get_additions(self) -> Generator[Tuple[int, int, int, int], None, None]:
- """Gets any newly added links.
-
- Yields:
- The source chain ID/sequence number and target chain ID/sequence number
- """
-
- for src_chain, src_seq, target_chain, _ in self.additions:
- target_seq = self.maps.get(src_chain, {}).get(target_chain, {}).get(src_seq)
- if target_seq is not None:
- yield (src_chain, src_seq, target_chain, target_seq)
-
- def exists_path_from(
- self,
- src_tuple: Tuple[int, int],
- target_tuple: Tuple[int, int],
- ) -> bool:
- """Checks if there is a path between the source chain ID/sequence and
- target chain ID/sequence.
- """
- src_chain, src_seq = src_tuple
- target_chain, target_seq = target_tuple
-
- if src_chain == target_chain:
- return target_seq <= src_seq
-
- links = self.get_links_between(src_chain, target_chain)
- for link_start_seq, link_end_seq in links:
- if link_start_seq <= src_seq and target_seq <= link_end_seq:
- return True
-
- return False
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