diff --git a/synapse/storage/stream.py b/synapse/storage/stream.py
deleted file mode 100644
index 490454f19a..0000000000
--- a/synapse/storage/stream.py
+++ /dev/null
@@ -1,948 +0,0 @@
-# -*- coding: utf-8 -*-
-# Copyright 2014-2016 OpenMarket Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-# http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-""" This module is responsible for getting events from the DB for pagination
-and event streaming.
-
-The order it returns events in depend on whether we are streaming forwards or
-are paginating backwards. We do this because we want to handle out of order
-messages nicely, while still returning them in the correct order when we
-paginate bacwards.
-
-This is implemented by keeping two ordering columns: stream_ordering and
-topological_ordering. Stream ordering is basically insertion/received order
-(except for events from backfill requests). The topological_ordering is a
-weak ordering of events based on the pdu graph.
-
-This means that we have to have two different types of tokens, depending on
-what sort order was used:
- - stream tokens are of the form: "s%d", which maps directly to the column
- - topological tokems: "t%d-%d", where the integers map to the topological
- and stream ordering columns respectively.
-"""
-
-import abc
-import logging
-from collections import namedtuple
-
-from six.moves import range
-
-from twisted.internet import defer
-
-from synapse.logging.context import make_deferred_yieldable, run_in_background
-from synapse.storage._base import SQLBaseStore
-from synapse.storage.engines import PostgresEngine
-from synapse.storage.events_worker import EventsWorkerStore
-from synapse.types import RoomStreamToken
-from synapse.util.caches.stream_change_cache import StreamChangeCache
-
-logger = logging.getLogger(__name__)
-
-
-MAX_STREAM_SIZE = 1000
-
-
-_STREAM_TOKEN = "stream"
-_TOPOLOGICAL_TOKEN = "topological"
-
-
-# Used as return values for pagination APIs
-_EventDictReturn = namedtuple(
- "_EventDictReturn", ("event_id", "topological_ordering", "stream_ordering")
-)
-
-
-def generate_pagination_where_clause(
- direction, column_names, from_token, to_token, engine
-):
- """Creates an SQL expression to bound the columns by the pagination
- tokens.
-
- For example creates an SQL expression like:
-
- (6, 7) >= (topological_ordering, stream_ordering)
- AND (5, 3) < (topological_ordering, stream_ordering)
-
- would be generated for dir=b, from_token=(6, 7) and to_token=(5, 3).
-
- Note that tokens are considered to be after the row they are in, e.g. if
- a row A has a token T, then we consider A to be before T. This convention
- is important when figuring out inequalities for the generated SQL, and
- produces the following result:
- - If paginating forwards then we exclude any rows matching the from
- token, but include those that match the to token.
- - If paginating backwards then we include any rows matching the from
- token, but include those that match the to token.
-
- Args:
- direction (str): Whether we're paginating backwards("b") or
- forwards ("f").
- column_names (tuple[str, str]): The column names to bound. Must *not*
- be user defined as these get inserted directly into the SQL
- statement without escapes.
- from_token (tuple[int, int]|None): The start point for the pagination.
- This is an exclusive minimum bound if direction is "f", and an
- inclusive maximum bound if direction is "b".
- to_token (tuple[int, int]|None): The endpoint point for the pagination.
- This is an inclusive maximum bound if direction is "f", and an
- exclusive minimum bound if direction is "b".
- engine: The database engine to generate the clauses for
-
- Returns:
- str: The sql expression
- """
- assert direction in ("b", "f")
-
- where_clause = []
- if from_token:
- where_clause.append(
- _make_generic_sql_bound(
- bound=">=" if direction == "b" else "<",
- column_names=column_names,
- values=from_token,
- engine=engine,
- )
- )
-
- if to_token:
- where_clause.append(
- _make_generic_sql_bound(
- bound="<" if direction == "b" else ">=",
- column_names=column_names,
- values=to_token,
- engine=engine,
- )
- )
-
- return " AND ".join(where_clause)
-
-
-def _make_generic_sql_bound(bound, column_names, values, engine):
- """Create an SQL expression that bounds the given column names by the
- values, e.g. create the equivalent of `(1, 2) < (col1, col2)`.
-
- Only works with two columns.
-
- Older versions of SQLite don't support that syntax so we have to expand it
- out manually.
-
- Args:
- bound (str): The comparison operator to use. One of ">", "<", ">=",
- "<=", where the values are on the left and columns on the right.
- names (tuple[str, str]): The column names. Must *not* be user defined
- as these get inserted directly into the SQL statement without
- escapes.
- values (tuple[int|None, int]): The values to bound the columns by. If
- the first value is None then only creates a bound on the second
- column.
- engine: The database engine to generate the SQL for
-
- Returns:
- str
- """
-
- assert bound in (">", "<", ">=", "<=")
-
- name1, name2 = column_names
- val1, val2 = values
-
- if val1 is None:
- val2 = int(val2)
- return "(%d %s %s)" % (val2, bound, name2)
-
- val1 = int(val1)
- val2 = int(val2)
-
- if isinstance(engine, PostgresEngine):
- # Postgres doesn't optimise ``(x < a) OR (x=a AND y<b)`` as well
- # as it optimises ``(x,y) < (a,b)`` on multicolumn indexes. So we
- # use the later form when running against postgres.
- return "((%d,%d) %s (%s,%s))" % (val1, val2, bound, name1, name2)
-
- # We want to generate queries of e.g. the form:
- #
- # (val1 < name1 OR (val1 = name1 AND val2 <= name2))
- #
- # which is equivalent to (val1, val2) < (name1, name2)
-
- return """(
- {val1:d} {strict_bound} {name1}
- OR ({val1:d} = {name1} AND {val2:d} {bound} {name2})
- )""".format(
- name1=name1,
- val1=val1,
- name2=name2,
- val2=val2,
- strict_bound=bound[0], # The first bound must always be strict equality here
- bound=bound,
- )
-
-
-def filter_to_clause(event_filter):
- # NB: This may create SQL clauses that don't optimise well (and we don't
- # have indices on all possible clauses). E.g. it may create
- # "room_id == X AND room_id != X", which postgres doesn't optimise.
-
- if not event_filter:
- return "", []
-
- clauses = []
- args = []
-
- if event_filter.types:
- clauses.append("(%s)" % " OR ".join("type = ?" for _ in event_filter.types))
- args.extend(event_filter.types)
-
- for typ in event_filter.not_types:
- clauses.append("type != ?")
- args.append(typ)
-
- if event_filter.senders:
- clauses.append("(%s)" % " OR ".join("sender = ?" for _ in event_filter.senders))
- args.extend(event_filter.senders)
-
- for sender in event_filter.not_senders:
- clauses.append("sender != ?")
- args.append(sender)
-
- if event_filter.rooms:
- clauses.append("(%s)" % " OR ".join("room_id = ?" for _ in event_filter.rooms))
- args.extend(event_filter.rooms)
-
- for room_id in event_filter.not_rooms:
- clauses.append("room_id != ?")
- args.append(room_id)
-
- if event_filter.contains_url:
- clauses.append("contains_url = ?")
- args.append(event_filter.contains_url)
-
- return " AND ".join(clauses), args
-
-
-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.
- """
-
- __metaclass__ = abc.ABCMeta
-
- def __init__(self, db_conn, hs):
- super(StreamWorkerStore, self).__init__(db_conn, hs)
-
- 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._stream_order_on_start = self.get_room_max_stream_ordering()
-
- @abc.abstractmethod
- def get_room_max_stream_ordering(self):
- raise NotImplementedError()
-
- @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, order="DESC"
- ):
- """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[dict[str,tuple[list[FrozenEvent], str]]]
- A map from room id to a tuple containing:
- - list of recent events in the room
- - stream ordering key for the start of the chunk of events returned.
- """
- from_id = RoomStreamToken.parse_stream_token(from_key).stream
-
- room_ids = yield self._events_stream_cache.get_entities_changed(
- room_ids, from_id
- )
-
- if not room_ids:
- return {}
-
- results = {}
- room_ids = list(room_ids)
- 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)))
-
- return results
-
- def get_rooms_that_changed(self, room_ids, from_key):
- """Given a list of rooms and a token, return rooms where there may have
- been changes.
-
- Args:
- room_ids (list)
- from_key (str): The room_key portion of a StreamToken
- """
- from_key = RoomStreamToken.parse_stream_token(from_key).stream
- return set(
- room_id
- for room_id in room_ids
- if self._events_stream_cache.has_entity_changed(room_id, from_key)
- )
-
- @defer.inlineCallbacks
- def get_room_events_stream_for_room(
- self, room_id, from_key, to_key, limit=0, order="DESC"
- ):
-
- """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:
- return [], from_key
-
- from_id = RoomStreamToken.parse_stream_token(from_key).stream
- to_id = RoomStreamToken.parse_stream_token(to_key).stream
-
- has_changed = yield self._events_stream_cache.has_entity_changed(
- room_id, from_id
- )
-
- if not has_changed:
- return [], 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_as_list(
- [r.event_id for r in rows], get_prev_content=True
- )
-
- self._set_before_and_after(ret, rows, topo_order=from_id is None)
-
- if order.lower() == "desc":
- ret.reverse()
-
- if 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.
- key = from_key
-
- return ret, key
-
- @defer.inlineCallbacks
- def get_membership_changes_for_user(self, user_id, from_key, to_key):
- from_id = RoomStreamToken.parse_stream_token(from_key).stream
- to_id = RoomStreamToken.parse_stream_token(to_key).stream
-
- if from_key == to_key:
- return []
-
- if from_id:
- has_changed = self._membership_stream_cache.has_entity_changed(
- user_id, int(from_id)
- )
- if not has_changed:
- return []
-
- def f(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_as_list(
- [r.event_id for r in rows], get_prev_content=True
- )
-
- self._set_before_and_after(ret, rows, topo_order=False)
-
- return ret
-
- @defer.inlineCallbacks
- def get_recent_events_for_room(self, room_id, limit, end_token):
- """Get the most recent events in the room in topological ordering.
-
- Args:
- room_id (str)
- limit (int)
- end_token (str): The stream token representing now.
-
- 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.
- """
-
- rows, token = yield self.get_recent_event_ids_for_room(
- room_id, limit, end_token
- )
-
- logger.debug("stream before")
- events = yield self.get_events_as_list(
- [r.event_id for r in rows], get_prev_content=True
- )
- logger.debug("stream after")
-
- self._set_before_and_after(events, rows)
-
- return (events, 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.
-
- Args:
- room_id (str)
- limit (int)
- end_token (str): The stream token representing now.
-
- 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:
- return [], end_token
-
- end_token = RoomStreamToken.parse(end_token)
-
- rows, token = yield self.runInteraction(
- "get_recent_event_ids_for_room",
- self._paginate_room_events_txn,
- room_id,
- from_token=end_token,
- limit=limit,
- )
-
- # We want to return the results in ascending order.
- rows.reverse()
-
- return 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):
-
- 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_room_event_after_stream_ordering", _f)
-
- @defer.inlineCallbacks
- def get_room_events_max_id(self, room_id=None):
- """Returns the current token for rooms stream.
-
- By default, it returns the current global stream token. Specifying a
- `room_id` causes it to return the current room specific topological
- token.
- """
- token = yield self.get_room_max_stream_ordering()
- if room_id is None:
- return "s%d" % (token,)
- else:
- topo = yield self.runInteraction(
- "_get_max_topological_txn", self._get_max_topological_txn, room_id
- )
- return "t%d-%d" % (topo, token)
-
- def get_stream_token_for_event(self, event_id):
- """The stream token for an event
- Args:
- event_id(str): The id of the event to look up a stream token for.
- Raises:
- StoreError if the event wasn't in the database.
- Returns:
- A deferred "s%d" stream token.
- """
- return self._simple_select_one_onecol(
- table="events", keyvalues={"event_id": event_id}, retcol="stream_ordering"
- ).addCallback(lambda row: "s%d" % (row,))
-
- def get_topological_token_for_event(self, event_id):
- """The stream token for an event
- Args:
- event_id(str): The id of the event to look up a stream token for.
- Raises:
- StoreError if the event wasn't in the database.
- Returns:
- A deferred "t%d-%d" topological token.
- """
- return self._simple_select_one(
- table="events",
- keyvalues={"event_id": event_id},
- retcols=("stream_ordering", "topological_ordering"),
- desc="get_topological_token_for_event",
- ).addCallback(
- lambda row: "t%d-%d" % (row["topological_ordering"], row["stream_ordering"])
- )
-
- def get_max_topological_token(self, room_id, stream_key):
- """Get the max topological token in a room before the given stream
- ordering.
-
- Args:
- room_id (str)
- stream_key (int)
-
- Returns:
- Deferred[int]
- """
- sql = (
- "SELECT coalesce(max(topological_ordering), 0) FROM events"
- " WHERE room_id = ? AND stream_ordering < ?"
- )
- return self._execute(
- "get_max_topological_token", None, sql, room_id, stream_key
- ).addCallback(lambda r: r[0][0] if r else 0)
-
- def _get_max_topological_txn(self, txn, room_id):
- txn.execute(
- "SELECT MAX(topological_ordering) FROM events" " WHERE room_id = ?",
- (room_id,),
- )
-
- rows = txn.fetchall()
- return rows[0][0] if rows else 0
-
- @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 and row.topological_ordering:
- topo = row.topological_ordering
- else:
- topo = None
- internal = event.internal_metadata
- internal.before = str(RoomStreamToken(topo, stream - 1))
- internal.after = str(RoomStreamToken(topo, stream))
- internal.order = (int(topo) if topo else 0, int(stream))
-
- @defer.inlineCallbacks
- def get_events_around(
- self, room_id, event_id, before_limit, after_limit, event_filter=None
- ):
- """Retrieve events and pagination tokens around a given event in a
- room.
-
- Args:
- room_id (str)
- event_id (str)
- before_limit (int)
- after_limit (int)
- event_filter (Filter|None)
-
- Returns:
- dict
- """
-
- results = yield self.runInteraction(
- "get_events_around",
- self._get_events_around_txn,
- room_id,
- event_id,
- before_limit,
- after_limit,
- event_filter,
- )
-
- events_before = yield self.get_events_as_list(
- [e for e in results["before"]["event_ids"]], get_prev_content=True
- )
-
- events_after = yield self.get_events_as_list(
- [e for e in results["after"]["event_ids"]], get_prev_content=True
- )
-
- return {
- "events_before": events_before,
- "events_after": events_after,
- "start": results["before"]["token"],
- "end": results["after"]["token"],
- }
-
- def _get_events_around_txn(
- self, txn, room_id, event_id, before_limit, after_limit, event_filter
- ):
- """Retrieves event_ids and pagination tokens around a given event in a
- room.
-
- Args:
- room_id (str)
- event_id (str)
- before_limit (int)
- after_limit (int)
- event_filter (Filter|None)
-
- Returns:
- dict
- """
-
- results = self._simple_select_one_txn(
- txn,
- "events",
- keyvalues={"event_id": event_id, "room_id": room_id},
- retcols=["stream_ordering", "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"]
- )
-
- after_token = RoomStreamToken(
- results["topological_ordering"], results["stream_ordering"]
- )
-
- rows, start_token = self._paginate_room_events_txn(
- txn,
- room_id,
- before_token,
- direction="b",
- limit=before_limit,
- event_filter=event_filter,
- )
- events_before = [r.event_id for r in rows]
-
- rows, end_token = self._paginate_room_events_txn(
- txn,
- room_id,
- after_token,
- direction="f",
- limit=after_limit,
- event_filter=event_filter,
- )
- events_after = [r.event_id for r in rows]
-
- return {
- "before": {"event_ids": events_before, "token": start_token},
- "after": {"event_ids": events_after, "token": end_token},
- }
-
- @defer.inlineCallbacks
- def get_all_new_events_stream(self, from_id, current_id, limit):
- """Get all new events
-
- Returns all events with from_id < stream_ordering <= current_id.
-
- Args:
- from_id (int): the stream_ordering of the last event we processed
- current_id (int): the stream_ordering of the most recently processed event
- limit (int): the maximum number of events to return
-
- Returns:
- Deferred[Tuple[int, list[FrozenEvent]]]: A tuple of (next_id, events), where
- `next_id` is the next value to pass as `from_id` (it will either be the
- stream_ordering of the last returned event, or, if fewer than `limit` events
- were found, `current_id`.
- """
-
- def get_all_new_events_stream_txn(txn):
- sql = (
- "SELECT e.stream_ordering, e.event_id"
- " FROM events AS e"
- " WHERE"
- " ? < e.stream_ordering AND e.stream_ordering <= ?"
- " ORDER BY e.stream_ordering ASC"
- " LIMIT ?"
- )
-
- txn.execute(sql, (from_id, current_id, limit))
- rows = txn.fetchall()
-
- upper_bound = current_id
- if len(rows) == limit:
- upper_bound = rows[-1][0]
-
- return upper_bound, [row[1] for row in rows]
-
- upper_bound, event_ids = yield self.runInteraction(
- "get_all_new_events_stream", get_all_new_events_stream_txn
- )
-
- events = yield self.get_events_as_list(event_ids)
-
- return upper_bound, events
-
- def get_federation_out_pos(self, typ):
- return self._simple_select_one_onecol(
- table="federation_stream_position",
- retcol="stream_id",
- keyvalues={"type": typ},
- desc="get_federation_out_pos",
- )
-
- def update_federation_out_pos(self, typ, stream_id):
- return self._simple_update_one(
- table="federation_stream_position",
- keyvalues={"type": typ},
- updatevalues={"stream_id": stream_id},
- desc="update_federation_out_pos",
- )
-
- 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. If no events are returned then the end of the
- stream has been reached (i.e. there are no events between
- `from_token` and `to_token`), or `limit` is zero.
- """
-
- 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"
- else:
- order = "ASC"
-
- bounds = generate_pagination_where_clause(
- direction=direction,
- column_names=("topological_ordering", "stream_ordering"),
- from_token=from_token,
- to_token=to_token,
- engine=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.
- event_filter (Filter|None): If provided filters the events to
- those that match the filter.
-
- Returns:
- tuple[list[FrozenEvent], str]: Returns the results as a list of
- events and a token that points to the end of the result set. If no
- events are returned then the end of the stream has been reached
- (i.e. there are no events between `from_key` and `to_key`).
- """
-
- 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_as_list(
- [r.event_id for r in rows], get_prev_content=True
- )
-
- self._set_before_and_after(events, rows)
-
- return (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()
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