diff options
Diffstat (limited to 'synapse/storage/stream.py')
| -rw-r--r-- | synapse/storage/stream.py | 683 |
1 files changed, 328 insertions, 355 deletions
diff --git a/synapse/storage/stream.py b/synapse/storage/stream.py index dddd5fc0e7..66856342f0 100644 --- a/synapse/storage/stream.py +++ b/synapse/storage/stream.py @@ -33,17 +33,20 @@ what sort order was used: and stream ordering columns respectively. """ -from twisted.internet import defer +import abc +import logging +from collections import namedtuple -from ._base import SQLBaseStore -from synapse.util.caches.descriptors import cached -from synapse.api.constants import EventTypes -from synapse.types import RoomStreamToken -from synapse.util.logcontext import preserve_fn, preserve_context_over_deferred -from synapse.storage.engines import PostgresEngine, Sqlite3Engine +from six.moves import range -import logging +from twisted.internet import defer +from synapse.storage._base import SQLBaseStore +from synapse.storage.engines import PostgresEngine +from synapse.storage.events import EventsWorkerStore +from synapse.types import RoomStreamToken +from synapse.util.caches.stream_change_cache import StreamChangeCache +from synapse.util.logcontext import make_deferred_yieldable, run_in_background logger = logging.getLogger(__name__) @@ -55,6 +58,12 @@ _STREAM_TOKEN = "stream" _TOPOLOGICAL_TOKEN = "topological" +# Used as return values for pagination APIs +_EventDictReturn = namedtuple("_EventDictReturn", ( + "event_id", "topological_ordering", "stream_ordering", +)) + + def lower_bound(token, engine, inclusive=False): inclusive = "=" if inclusive else "" if token.topological is None: @@ -143,81 +152,41 @@ def filter_to_clause(event_filter): return " AND ".join(clauses), args -class StreamStore(SQLBaseStore): - @defer.inlineCallbacks - def get_appservice_room_stream(self, service, from_key, to_key, limit=0): - # NB this lives here instead of appservice.py so we can reuse the - # 'private' StreamToken class in this file. - if limit: - limit = max(limit, MAX_STREAM_SIZE) - else: - limit = MAX_STREAM_SIZE - - # From and to keys should be integers from ordering. - from_id = RoomStreamToken.parse_stream_token(from_key) - to_id = RoomStreamToken.parse_stream_token(to_key) - - if from_key == to_key: - defer.returnValue(([], to_key)) - return +class StreamWorkerStore(EventsWorkerStore, SQLBaseStore): + """This is an abstract base class where subclasses must implement + `get_room_max_stream_ordering` and `get_room_min_stream_ordering` + which can be called in the initializer. + """ - # select all the events between from/to with a sensible limit - sql = ( - "SELECT e.event_id, e.room_id, e.type, s.state_key, " - "e.stream_ordering FROM events AS e " - "LEFT JOIN state_events as s ON " - "e.event_id = s.event_id " - "WHERE e.stream_ordering > ? AND e.stream_ordering <= ? " - "ORDER BY stream_ordering ASC LIMIT %(limit)d " - ) % { - "limit": limit - } + __metaclass__ = abc.ABCMeta - def f(txn): - # pull out all the events between the tokens - txn.execute(sql, (from_id.stream, to_id.stream,)) - rows = self.cursor_to_dict(txn) - - # Logic: - # - We want ALL events which match the AS room_id regex - # - We want ALL events which match the rooms represented by the AS - # room_alias regex - # - We want ALL events for rooms that AS users have joined. - # This is currently supported via get_app_service_rooms (which is - # used for the Notifier listener rooms). We can't reasonably make a - # SQL query for these room IDs, so we'll pull all the events between - # from/to and filter in python. - rooms_for_as = self._get_app_service_rooms_txn(txn, service) - room_ids_for_as = [r.room_id for r in rooms_for_as] - - def app_service_interested(row): - if row["room_id"] in room_ids_for_as: - return True - - if row["type"] == EventTypes.Member: - if service.is_interested_in_user(row.get("state_key")): - return True - return False - - return [r for r in rows if app_service_interested(r)] - - rows = yield self.runInteraction("get_appservice_room_stream", f) + def __init__(self, db_conn, hs): + super(StreamWorkerStore, self).__init__(db_conn, hs) - ret = yield self._get_events( - [r["event_id"] for r in rows], - get_prev_content=True + events_max = self.get_room_max_stream_ordering() + event_cache_prefill, min_event_val = self._get_cache_dict( + db_conn, "events", + entity_column="room_id", + stream_column="stream_ordering", + max_value=events_max, + ) + self._events_stream_cache = StreamChangeCache( + "EventsRoomStreamChangeCache", min_event_val, + prefilled_cache=event_cache_prefill, + ) + self._membership_stream_cache = StreamChangeCache( + "MembershipStreamChangeCache", events_max, ) - self._set_before_and_after(ret, rows, topo_order=from_id is None) + self._stream_order_on_start = self.get_room_max_stream_ordering() - if rows: - key = "s%d" % max(r["stream_ordering"] for r in rows) - else: - # Assume we didn't get anything because there was nothing to - # get. - key = to_key + @abc.abstractmethod + def get_room_max_stream_ordering(self): + raise NotImplementedError() - defer.returnValue((ret, key)) + @abc.abstractmethod + def get_room_min_stream_ordering(self): + raise NotImplementedError() @defer.inlineCallbacks def get_room_events_stream_for_rooms(self, room_ids, from_key, to_key, limit=0, @@ -233,13 +202,14 @@ class StreamStore(SQLBaseStore): results = {} room_ids = list(room_ids) - for rm_ids in (room_ids[i:i + 20] for i in xrange(0, len(room_ids), 20)): - res = yield preserve_context_over_deferred(defer.gatherResults([ - preserve_fn(self.get_room_events_stream_for_room)( + for rm_ids in (room_ids[i:i + 20] for i in range(0, len(room_ids), 20)): + res = yield make_deferred_yieldable(defer.gatherResults([ + run_in_background( + self.get_room_events_stream_for_room, room_id, from_key, to_key, limit, order=order, ) for room_id in rm_ids - ])) + ], consumeErrors=True)) results.update(dict(zip(rm_ids, res))) defer.returnValue(results) @@ -261,54 +231,55 @@ class StreamStore(SQLBaseStore): @defer.inlineCallbacks def get_room_events_stream_for_room(self, room_id, from_key, to_key, limit=0, order='DESC'): - # Note: If from_key is None then we return in topological order. This - # is because in that case we're using this as a "get the last few messages - # in a room" function, rather than "get new messages since last sync" - if from_key is not None: - from_id = RoomStreamToken.parse_stream_token(from_key).stream - else: - from_id = None - to_id = RoomStreamToken.parse_stream_token(to_key).stream + """Get new room events in stream ordering since `from_key`. + + Args: + room_id (str) + from_key (str): Token from which no events are returned before + to_key (str): Token from which no events are returned after. (This + is typically the current stream token) + limit (int): Maximum number of events to return + order (str): Either "DESC" or "ASC". Determines which events are + returned when the result is limited. If "DESC" then the most + recent `limit` events are returned, otherwise returns the + oldest `limit` events. + + Returns: + Deferred[tuple[list[FrozenEvent], str]]: Returns the list of + events (in ascending order) and the token from the start of + the chunk of events returned. + """ if from_key == to_key: defer.returnValue(([], from_key)) - if from_id: - has_changed = yield self._events_stream_cache.has_entity_changed( - room_id, from_id - ) - - if not has_changed: - defer.returnValue(([], from_key)) + from_id = RoomStreamToken.parse_stream_token(from_key).stream + to_id = RoomStreamToken.parse_stream_token(to_key).stream - def f(txn): - if from_id is not None: - sql = ( - "SELECT event_id, stream_ordering FROM events WHERE" - " room_id = ?" - " AND not outlier" - " AND stream_ordering > ? AND stream_ordering <= ?" - " ORDER BY stream_ordering %s LIMIT ?" - ) % (order,) - txn.execute(sql, (room_id, from_id, to_id, limit)) - else: - sql = ( - "SELECT event_id, stream_ordering FROM events WHERE" - " room_id = ?" - " AND not outlier" - " AND stream_ordering <= ?" - " ORDER BY topological_ordering %s, stream_ordering %s LIMIT ?" - ) % (order, order,) - txn.execute(sql, (room_id, to_id, limit)) + has_changed = yield self._events_stream_cache.has_entity_changed( + room_id, from_id + ) - rows = self.cursor_to_dict(txn) + if not has_changed: + defer.returnValue(([], from_key)) + def f(txn): + sql = ( + "SELECT event_id, stream_ordering FROM events WHERE" + " room_id = ?" + " AND not outlier" + " AND stream_ordering > ? AND stream_ordering <= ?" + " ORDER BY stream_ordering %s LIMIT ?" + ) % (order,) + txn.execute(sql, (room_id, from_id, to_id, limit)) + + rows = [_EventDictReturn(row[0], None, row[1]) for row in txn] return rows rows = yield self.runInteraction("get_room_events_stream_for_room", f) ret = yield self._get_events( - [r["event_id"] for r in rows], + [r.event_id for r in rows], get_prev_content=True ) @@ -318,7 +289,7 @@ class StreamStore(SQLBaseStore): ret.reverse() if rows: - key = "s%d" % min(r["stream_ordering"] for r in rows) + key = "s%d" % min(r.stream_ordering for r in rows) else: # Assume we didn't get anything because there was nothing to # get. @@ -328,10 +299,7 @@ class StreamStore(SQLBaseStore): @defer.inlineCallbacks def get_membership_changes_for_user(self, user_id, from_key, to_key): - if from_key is not None: - from_id = RoomStreamToken.parse_stream_token(from_key).stream - else: - from_id = None + from_id = RoomStreamToken.parse_stream_token(from_key).stream to_id = RoomStreamToken.parse_stream_token(to_key).stream if from_key == to_key: @@ -345,34 +313,24 @@ class StreamStore(SQLBaseStore): defer.returnValue([]) def f(txn): - if from_id is not None: - sql = ( - "SELECT m.event_id, stream_ordering FROM events AS e," - " room_memberships AS m" - " WHERE e.event_id = m.event_id" - " AND m.user_id = ?" - " AND e.stream_ordering > ? AND e.stream_ordering <= ?" - " ORDER BY e.stream_ordering ASC" - ) - txn.execute(sql, (user_id, from_id, to_id,)) - else: - sql = ( - "SELECT m.event_id, stream_ordering FROM events AS e," - " room_memberships AS m" - " WHERE e.event_id = m.event_id" - " AND m.user_id = ?" - " AND stream_ordering <= ?" - " ORDER BY stream_ordering ASC" - ) - txn.execute(sql, (user_id, to_id,)) - rows = self.cursor_to_dict(txn) + sql = ( + "SELECT m.event_id, stream_ordering FROM events AS e," + " room_memberships AS m" + " WHERE e.event_id = m.event_id" + " AND m.user_id = ?" + " AND e.stream_ordering > ? AND e.stream_ordering <= ?" + " ORDER BY e.stream_ordering ASC" + ) + txn.execute(sql, (user_id, from_id, to_id,)) + + rows = [_EventDictReturn(row[0], None, row[1]) for row in txn] return rows rows = yield self.runInteraction("get_membership_changes_for_user", f) ret = yield self._get_events( - [r["event_id"] for r in rows], + [r.event_id for r in rows], get_prev_content=True ) @@ -381,96 +339,28 @@ class StreamStore(SQLBaseStore): defer.returnValue(ret) @defer.inlineCallbacks - def paginate_room_events(self, room_id, from_key, to_key=None, - direction='b', limit=-1, event_filter=None): - # Tokens really represent positions between elements, but we use - # the convention of pointing to the event before the gap. Hence - # we have a bit of asymmetry when it comes to equalities. - args = [False, room_id] - if direction == 'b': - order = "DESC" - bounds = upper_bound( - RoomStreamToken.parse(from_key), self.database_engine - ) - if to_key: - bounds = "%s AND %s" % (bounds, lower_bound( - RoomStreamToken.parse(to_key), self.database_engine - )) - else: - order = "ASC" - bounds = lower_bound( - RoomStreamToken.parse(from_key), self.database_engine - ) - if to_key: - bounds = "%s AND %s" % (bounds, upper_bound( - RoomStreamToken.parse(to_key), self.database_engine - )) - - filter_clause, filter_args = filter_to_clause(event_filter) - - if filter_clause: - bounds += " AND " + filter_clause - args.extend(filter_args) - - if int(limit) > 0: - args.append(int(limit)) - limit_str = " LIMIT ?" - else: - limit_str = "" - - sql = ( - "SELECT * FROM events" - " WHERE outlier = ? AND room_id = ? AND %(bounds)s" - " ORDER BY topological_ordering %(order)s," - " stream_ordering %(order)s %(limit)s" - ) % { - "bounds": bounds, - "order": order, - "limit": limit_str - } - - def f(txn): - txn.execute(sql, args) - - rows = self.cursor_to_dict(txn) - - if rows: - topo = rows[-1]["topological_ordering"] - toke = rows[-1]["stream_ordering"] - if direction == 'b': - # Tokens are positions between events. - # This token points *after* the last event in the chunk. - # We need it to point to the event before it in the chunk - # when we are going backwards so we subtract one from the - # stream part. - toke -= 1 - next_token = str(RoomStreamToken(topo, toke)) - else: - # TODO (erikj): We should work out what to do here instead. - next_token = to_key if to_key else from_key + def get_recent_events_for_room(self, room_id, limit, end_token): + """Get the most recent events in the room in topological ordering. - return rows, next_token, - - rows, token = yield self.runInteraction("paginate_room_events", f) - - events = yield self._get_events( - [r["event_id"] for r in rows], - get_prev_content=True - ) - - self._set_before_and_after(events, rows) + Args: + room_id (str) + limit (int) + end_token (str): The stream token representing now. - defer.returnValue((events, token)) + Returns: + Deferred[tuple[list[FrozenEvent], str]]: Returns a list of + events and a token pointing to the start of the returned + events. + The events returned are in ascending order. + """ - @defer.inlineCallbacks - def get_recent_events_for_room(self, room_id, limit, end_token, from_token=None): rows, token = yield self.get_recent_event_ids_for_room( - room_id, limit, end_token, from_token + room_id, limit, end_token, ) logger.debug("stream before") events = yield self._get_events( - [r["event_id"] for r in rows], + [r.event_id for r in rows], get_prev_content=True ) logger.debug("stream after") @@ -479,59 +369,62 @@ class StreamStore(SQLBaseStore): defer.returnValue((events, token)) - @cached(num_args=4) - def get_recent_event_ids_for_room(self, room_id, limit, end_token, from_token=None): - end_token = RoomStreamToken.parse_stream_token(end_token) + @defer.inlineCallbacks + def get_recent_event_ids_for_room(self, room_id, limit, end_token): + """Get the most recent events in the room in topological ordering. - if from_token is None: - sql = ( - "SELECT stream_ordering, topological_ordering, event_id" - " FROM events" - " WHERE room_id = ? AND stream_ordering <= ? AND outlier = ?" - " ORDER BY topological_ordering DESC, stream_ordering DESC" - " LIMIT ?" - ) - else: - from_token = RoomStreamToken.parse_stream_token(from_token) - sql = ( - "SELECT stream_ordering, topological_ordering, event_id" - " FROM events" - " WHERE room_id = ? AND stream_ordering > ?" - " AND stream_ordering <= ? AND outlier = ?" - " ORDER BY topological_ordering DESC, stream_ordering DESC" - " LIMIT ?" - ) + Args: + room_id (str) + limit (int) + end_token (str): The stream token representing now. - def get_recent_events_for_room_txn(txn): - if from_token is None: - txn.execute(sql, (room_id, end_token.stream, False, limit,)) - else: - txn.execute(sql, ( - room_id, from_token.stream, end_token.stream, False, limit - )) + Returns: + Deferred[tuple[list[_EventDictReturn], str]]: Returns a list of + _EventDictReturn and a token pointing to the start of the returned + events. + The events returned are in ascending order. + """ + # Allow a zero limit here, and no-op. + if limit == 0: + defer.returnValue(([], end_token)) - rows = self.cursor_to_dict(txn) + end_token = RoomStreamToken.parse(end_token) - rows.reverse() # As we selected with reverse ordering + rows, token = yield self.runInteraction( + "get_recent_event_ids_for_room", self._paginate_room_events_txn, + room_id, from_token=end_token, limit=limit, + ) - if rows: - # Tokens are positions between events. - # This token points *after* the last event in the chunk. - # We need it to point to the event before it in the chunk - # since we are going backwards so we subtract one from the - # stream part. - topo = rows[0]["topological_ordering"] - toke = rows[0]["stream_ordering"] - 1 - start_token = str(RoomStreamToken(topo, toke)) + # We want to return the results in ascending order. + rows.reverse() - token = (start_token, str(end_token)) - else: - token = (str(end_token), str(end_token)) + defer.returnValue((rows, token)) + + def get_room_event_after_stream_ordering(self, room_id, stream_ordering): + """Gets details of the first event in a room at or after a stream ordering + + Args: + room_id (str): + stream_ordering (int): - return rows, token + Returns: + Deferred[(int, int, str)]: + (stream ordering, topological ordering, event_id) + """ + def _f(txn): + sql = ( + "SELECT stream_ordering, topological_ordering, event_id" + " FROM events" + " WHERE room_id = ? AND stream_ordering >= ?" + " AND NOT outlier" + " ORDER BY stream_ordering" + " LIMIT 1" + ) + txn.execute(sql, (room_id, stream_ordering, )) + return txn.fetchone() return self.runInteraction( - "get_recent_events_for_room", get_recent_events_for_room_txn + "get_room_event_after_stream_ordering", _f, ) @defer.inlineCallbacks @@ -542,7 +435,7 @@ class StreamStore(SQLBaseStore): `room_id` causes it to return the current room specific topological token. """ - token = yield self._stream_id_gen.get_current_token() + token = yield self.get_room_max_stream_ordering() if room_id is None: defer.returnValue("s%d" % (token,)) else: @@ -552,12 +445,6 @@ class StreamStore(SQLBaseStore): ) defer.returnValue("t%d-%d" % (topo, token)) - def get_room_max_stream_ordering(self): - return self._stream_id_gen.get_current_token() - - def get_room_min_stream_ordering(self): - return self._backfill_id_gen.get_current_token() - def get_stream_token_for_event(self, event_id): """The stream token for an event Args: @@ -615,10 +502,20 @@ class StreamStore(SQLBaseStore): @staticmethod def _set_before_and_after(events, rows, topo_order=True): + """Inserts ordering information to events' internal metadata from + the DB rows. + + Args: + events (list[FrozenEvent]) + rows (list[_EventDictReturn]) + topo_order (bool): Whether the events were ordered topologically + or by stream ordering. If true then all rows should have a non + null topological_ordering. + """ for event, row in zip(events, rows): - stream = row["stream_ordering"] - if topo_order: - topo = event.depth + stream = row.stream_ordering + if topo_order and row.topological_ordering: + topo = row.topological_ordering else: topo = None internal = event.internal_metadata @@ -690,87 +587,27 @@ class StreamStore(SQLBaseStore): retcols=["stream_ordering", "topological_ordering"], ) - token = RoomStreamToken( - results["topological_ordering"], + # Paginating backwards includes the event at the token, but paginating + # forward doesn't. + before_token = RoomStreamToken( + results["topological_ordering"] - 1, results["stream_ordering"], ) - if isinstance(self.database_engine, Sqlite3Engine): - # SQLite3 doesn't optimise ``(x < a) OR (x = a AND y < b)`` - # So we give pass it to SQLite3 as the UNION ALL of the two queries. - - query_before = ( - "SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND topological_ordering < ?" - " UNION ALL" - " SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND topological_ordering = ? AND stream_ordering < ?" - " ORDER BY topological_ordering DESC, stream_ordering DESC LIMIT ?" - ) - before_args = ( - room_id, token.topological, - room_id, token.topological, token.stream, - before_limit, - ) - - query_after = ( - "SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND topological_ordering > ?" - " UNION ALL" - " SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND topological_ordering = ? AND stream_ordering > ?" - " ORDER BY topological_ordering ASC, stream_ordering ASC LIMIT ?" - ) - after_args = ( - room_id, token.topological, - room_id, token.topological, token.stream, - after_limit, - ) - else: - query_before = ( - "SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND %s" - " ORDER BY topological_ordering DESC, stream_ordering DESC LIMIT ?" - ) % (upper_bound(token, self.database_engine, inclusive=False),) - - before_args = (room_id, before_limit) - - query_after = ( - "SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND %s" - " ORDER BY topological_ordering ASC, stream_ordering ASC LIMIT ?" - ) % (lower_bound(token, self.database_engine, inclusive=False),) - - after_args = (room_id, after_limit) - - txn.execute(query_before, before_args) - - rows = self.cursor_to_dict(txn) - events_before = [r["event_id"] for r in rows] - - if rows: - start_token = str(RoomStreamToken( - rows[0]["topological_ordering"], - rows[0]["stream_ordering"] - 1, - )) - else: - start_token = str(RoomStreamToken( - token.topological, - token.stream - 1, - )) - - txn.execute(query_after, after_args) + after_token = RoomStreamToken( + results["topological_ordering"], + results["stream_ordering"], + ) - rows = self.cursor_to_dict(txn) - events_after = [r["event_id"] for r in rows] + rows, start_token = self._paginate_room_events_txn( + txn, room_id, before_token, direction='b', limit=before_limit, + ) + events_before = [r.event_id for r in rows] - if rows: - end_token = str(RoomStreamToken( - rows[-1]["topological_ordering"], - rows[-1]["stream_ordering"], - )) - else: - end_token = str(token) + rows, end_token = self._paginate_room_events_txn( + txn, room_id, after_token, direction='f', limit=after_limit, + ) + events_after = [r.event_id for r in rows] return { "before": { @@ -832,3 +669,139 @@ class StreamStore(SQLBaseStore): def has_room_changed_since(self, room_id, stream_id): return self._events_stream_cache.has_entity_changed(room_id, stream_id) + + def _paginate_room_events_txn(self, txn, room_id, from_token, to_token=None, + direction='b', limit=-1, event_filter=None): + """Returns list of events before or after a given token. + + Args: + txn + room_id (str) + from_token (RoomStreamToken): The token used to stream from + to_token (RoomStreamToken|None): A token which if given limits the + results to only those before + direction(char): Either 'b' or 'f' to indicate whether we are + paginating forwards or backwards from `from_key`. + limit (int): The maximum number of events to return. + event_filter (Filter|None): If provided filters the events to + those that match the filter. + + Returns: + Deferred[tuple[list[_EventDictReturn], str]]: Returns the results + as a list of _EventDictReturn and a token that points to the end + of the result set. + """ + + assert int(limit) >= 0 + + # Tokens really represent positions between elements, but we use + # the convention of pointing to the event before the gap. Hence + # we have a bit of asymmetry when it comes to equalities. + args = [False, room_id] + if direction == 'b': + order = "DESC" + bounds = upper_bound( + from_token, self.database_engine + ) + if to_token: + bounds = "%s AND %s" % (bounds, lower_bound( + to_token, self.database_engine + )) + else: + order = "ASC" + bounds = lower_bound( + from_token, self.database_engine + ) + if to_token: + bounds = "%s AND %s" % (bounds, upper_bound( + to_token, self.database_engine + )) + + filter_clause, filter_args = filter_to_clause(event_filter) + + if filter_clause: + bounds += " AND " + filter_clause + args.extend(filter_args) + + args.append(int(limit)) + + sql = ( + "SELECT event_id, topological_ordering, stream_ordering" + " FROM events" + " WHERE outlier = ? AND room_id = ? AND %(bounds)s" + " ORDER BY topological_ordering %(order)s," + " stream_ordering %(order)s LIMIT ?" + ) % { + "bounds": bounds, + "order": order, + } + + txn.execute(sql, args) + + rows = [_EventDictReturn(row[0], row[1], row[2]) for row in txn] + + if rows: + topo = rows[-1].topological_ordering + toke = rows[-1].stream_ordering + if direction == 'b': + # Tokens are positions between events. + # This token points *after* the last event in the chunk. + # We need it to point to the event before it in the chunk + # when we are going backwards so we subtract one from the + # stream part. + toke -= 1 + next_token = RoomStreamToken(topo, toke) + else: + # TODO (erikj): We should work out what to do here instead. + next_token = to_token if to_token else from_token + + return rows, str(next_token), + + @defer.inlineCallbacks + def paginate_room_events(self, room_id, from_key, to_key=None, + direction='b', limit=-1, event_filter=None): + """Returns list of events before or after a given token. + + Args: + room_id (str) + from_key (str): The token used to stream from + to_key (str|None): A token which if given limits the results to + only those before + direction(char): Either 'b' or 'f' to indicate whether we are + paginating forwards or backwards from `from_key`. + limit (int): The maximum number of events to return. Zero or less + means no limit. + event_filter (Filter|None): If provided filters the events to + those that match the filter. + + Returns: + tuple[list[dict], str]: Returns the results as a list of dicts and + a token that points to the end of the result set. The dicts have + the keys "event_id", "topological_ordering" and "stream_orderign". + """ + + from_key = RoomStreamToken.parse(from_key) + if to_key: + to_key = RoomStreamToken.parse(to_key) + + rows, token = yield self.runInteraction( + "paginate_room_events", self._paginate_room_events_txn, + room_id, from_key, to_key, direction, limit, event_filter, + ) + + events = yield self._get_events( + [r.event_id for r in rows], + get_prev_content=True + ) + + self._set_before_and_after(events, rows) + + defer.returnValue((events, token)) + + +class StreamStore(StreamWorkerStore): + def get_room_max_stream_ordering(self): + return self._stream_id_gen.get_current_token() + + def get_room_min_stream_ordering(self): + return self._backfill_id_gen.get_current_token() |