603 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			603 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			Python
		
	
	
| # -*- coding: utf-8 -*-
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| # Copyright 2014-2016 OpenMarket Ltd
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| #
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| # Licensed under the Apache License, Version 2.0 (the "License");
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| # you may not use this file except in compliance with the License.
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| # You may obtain a copy of the License at
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| #
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| #     http://www.apache.org/licenses/LICENSE-2.0
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| #
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| # Unless required by applicable law or agreed to in writing, software
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| # distributed under the License is distributed on an "AS IS" BASIS,
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| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| # See the License for the specific language governing permissions and
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| # limitations under the License.
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| 
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| """ This module is responsible for getting events from the DB for pagination
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| and event streaming.
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| 
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| The order it returns events in depend on whether we are streaming forwards or
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| are paginating backwards. We do this because we want to handle out of order
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| messages nicely, while still returning them in the correct order when we
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| paginate bacwards.
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| 
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| This is implemented by keeping two ordering columns: stream_ordering and
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| topological_ordering. Stream ordering is basically insertion/received order
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| (except for events from backfill requests). The topological_ordering is a
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| weak ordering of events based on the pdu graph.
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| 
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| This means that we have to have two different types of tokens, depending on
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| what sort order was used:
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|     - stream tokens are of the form: "s%d", which maps directly to the column
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|     - topological tokems: "t%d-%d", where the integers map to the topological
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|       and stream ordering columns respectively.
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| """
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| 
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| from twisted.internet import defer
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| 
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| from ._base import SQLBaseStore
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| from synapse.util.caches.descriptors import cachedInlineCallbacks
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| from synapse.api.constants import EventTypes
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| from synapse.types import RoomStreamToken
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| from synapse.util.logutils import log_function
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| 
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| import logging
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| 
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| 
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| logger = logging.getLogger(__name__)
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| 
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| 
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| MAX_STREAM_SIZE = 1000
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| 
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| 
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| _STREAM_TOKEN = "stream"
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| _TOPOLOGICAL_TOKEN = "topological"
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| 
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| 
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| def lower_bound(token):
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|     if token.topological is None:
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|         return "(%d < %s)" % (token.stream, "stream_ordering")
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|     else:
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|         return "(%d < %s OR (%d = %s AND %d < %s))" % (
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|             token.topological, "topological_ordering",
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|             token.topological, "topological_ordering",
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|             token.stream, "stream_ordering",
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|         )
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| 
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| 
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| def upper_bound(token):
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|     if token.topological is None:
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|         return "(%d >= %s)" % (token.stream, "stream_ordering")
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|     else:
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|         return "(%d > %s OR (%d = %s AND %d >= %s))" % (
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|             token.topological, "topological_ordering",
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|             token.topological, "topological_ordering",
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|             token.stream, "stream_ordering",
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|         )
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| 
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| 
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| class StreamStore(SQLBaseStore):
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| 
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|     @defer.inlineCallbacks
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|     def get_appservice_room_stream(self, service, from_key, to_key, limit=0):
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|         # NB this lives here instead of appservice.py so we can reuse the
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|         # 'private' StreamToken class in this file.
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|         if limit:
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|             limit = max(limit, MAX_STREAM_SIZE)
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|         else:
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|             limit = MAX_STREAM_SIZE
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| 
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|         # From and to keys should be integers from ordering.
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|         from_id = RoomStreamToken.parse_stream_token(from_key)
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|         to_id = RoomStreamToken.parse_stream_token(to_key)
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| 
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|         if from_key == to_key:
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|             defer.returnValue(([], to_key))
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|             return
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| 
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|         # select all the events between from/to with a sensible limit
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|         sql = (
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|             "SELECT e.event_id, e.room_id, e.type, s.state_key, "
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|             "e.stream_ordering FROM events AS e "
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|             "LEFT JOIN state_events as s ON "
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|             "e.event_id = s.event_id "
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|             "WHERE e.stream_ordering > ? AND e.stream_ordering <= ? "
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|             "ORDER BY stream_ordering ASC LIMIT %(limit)d "
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|         ) % {
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|             "limit": limit
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|         }
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| 
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|         def f(txn):
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|             # pull out all the events between the tokens
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|             txn.execute(sql, (from_id.stream, to_id.stream,))
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|             rows = self.cursor_to_dict(txn)
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| 
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|             # Logic:
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|             #  - We want ALL events which match the AS room_id regex
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|             #  - We want ALL events which match the rooms represented by the AS
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|             #    room_alias regex
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|             #  - We want ALL events for rooms that AS users have joined.
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|             # This is currently supported via get_app_service_rooms (which is
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|             # used for the Notifier listener rooms). We can't reasonably make a
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|             # SQL query for these room IDs, so we'll pull all the events between
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|             # from/to and filter in python.
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|             rooms_for_as = self._get_app_service_rooms_txn(txn, service)
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|             room_ids_for_as = [r.room_id for r in rooms_for_as]
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| 
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|             def app_service_interested(row):
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|                 if row["room_id"] in room_ids_for_as:
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|                     return True
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| 
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|                 if row["type"] == EventTypes.Member:
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|                     if service.is_interested_in_user(row.get("state_key")):
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|                         return True
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|                 return False
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| 
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|             ret = self._get_events_txn(
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|                 txn,
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|                 # apply the filter on the room id list
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|                 [
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|                     r["event_id"] for r in rows
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|                     if app_service_interested(r)
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|                 ],
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|                 get_prev_content=True
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|             )
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| 
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|             self._set_before_and_after(ret, rows)
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| 
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|             if rows:
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|                 key = "s%d" % max(r["stream_ordering"] for r in rows)
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|             else:
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|                 # Assume we didn't get anything because there was nothing to
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|                 # get.
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|                 key = to_key
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| 
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|             return ret, key
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| 
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|         results = yield self.runInteraction("get_appservice_room_stream", f)
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|         defer.returnValue(results)
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| 
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|     @log_function
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|     def get_room_events_stream(
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|         self,
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|         user_id,
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|         from_key,
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|         to_key,
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|         limit=0,
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|         is_guest=False,
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|         room_ids=None
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|     ):
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|         room_ids = room_ids or []
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|         room_ids = [r for r in room_ids]
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|         if is_guest:
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|             current_room_membership_sql = (
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|                 "SELECT c.room_id FROM history_visibility AS h"
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|                 " INNER JOIN current_state_events AS c"
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|                 " ON h.event_id = c.event_id"
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|                 " WHERE c.room_id IN (%s) AND h.history_visibility = 'world_readable'" % (
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|                     ",".join(map(lambda _: "?", room_ids))
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|                 )
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|             )
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|             current_room_membership_args = room_ids
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|         else:
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|             current_room_membership_sql = (
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|                 "SELECT m.room_id FROM room_memberships as m "
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|                 " INNER JOIN current_state_events as c"
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|                 " ON m.event_id = c.event_id AND c.state_key = m.user_id"
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|                 " WHERE m.user_id = ? AND m.membership = 'join'"
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|             )
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|             current_room_membership_args = [user_id]
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|             if room_ids:
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|                 current_room_membership_sql += " AND m.room_id in (%s)" % (
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|                     ",".join(map(lambda _: "?", room_ids))
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|                 )
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|                 current_room_membership_args = [user_id] + room_ids
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| 
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|         # We also want to get any membership events about that user, e.g.
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|         # invites or leave notifications.
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|         membership_sql = (
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|             "SELECT m.event_id FROM room_memberships as m "
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|             "INNER JOIN current_state_events as c ON m.event_id = c.event_id "
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|             "WHERE m.user_id = ? "
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|         )
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|         membership_args = [user_id]
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| 
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|         if limit:
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|             limit = max(limit, MAX_STREAM_SIZE)
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|         else:
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|             limit = MAX_STREAM_SIZE
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| 
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|         # From and to keys should be integers from ordering.
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|         from_id = RoomStreamToken.parse_stream_token(from_key)
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|         to_id = RoomStreamToken.parse_stream_token(to_key)
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| 
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|         if from_key == to_key:
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|             return defer.succeed(([], to_key))
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| 
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|         sql = (
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|             "SELECT e.event_id, e.stream_ordering FROM events AS e WHERE "
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|             "(e.outlier = ? AND (room_id IN (%(current)s)) OR "
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|             "(event_id IN (%(invites)s))) "
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|             "AND e.stream_ordering > ? AND e.stream_ordering <= ? "
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|             "ORDER BY stream_ordering ASC LIMIT %(limit)d "
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|         ) % {
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|             "current": current_room_membership_sql,
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|             "invites": membership_sql,
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|             "limit": limit
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|         }
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| 
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|         def f(txn):
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|             args = ([False] + current_room_membership_args + membership_args +
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|                     [from_id.stream, to_id.stream])
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|             txn.execute(sql, args)
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| 
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|             rows = self.cursor_to_dict(txn)
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| 
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|             ret = self._get_events_txn(
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|                 txn,
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|                 [r["event_id"] for r in rows],
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|                 get_prev_content=True
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|             )
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| 
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|             self._set_before_and_after(ret, rows)
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| 
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|             if rows:
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|                 key = "s%d" % max(r["stream_ordering"] for r in rows)
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|             else:
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|                 # Assume we didn't get anything because there was nothing to
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|                 # get.
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|                 key = to_key
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| 
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|             return ret, key
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| 
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|         return self.runInteraction("get_room_events_stream", f)
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| 
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|     @defer.inlineCallbacks
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|     def paginate_room_events(self, room_id, from_key, to_key=None,
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|                              direction='b', limit=-1):
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|         # Tokens really represent positions between elements, but we use
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|         # the convention of pointing to the event before the gap. Hence
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|         # we have a bit of asymmetry when it comes to equalities.
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|         args = [False, room_id]
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|         if direction == 'b':
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|             order = "DESC"
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|             bounds = upper_bound(RoomStreamToken.parse(from_key))
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|             if to_key:
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|                 bounds = "%s AND %s" % (
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|                     bounds, lower_bound(RoomStreamToken.parse(to_key))
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|                 )
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|         else:
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|             order = "ASC"
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|             bounds = lower_bound(RoomStreamToken.parse(from_key))
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|             if to_key:
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|                 bounds = "%s AND %s" % (
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|                     bounds, upper_bound(RoomStreamToken.parse(to_key))
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|                 )
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| 
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|         if int(limit) > 0:
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|             args.append(int(limit))
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|             limit_str = " LIMIT ?"
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|         else:
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|             limit_str = ""
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| 
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|         sql = (
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|             "SELECT * FROM events"
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|             " WHERE outlier = ? AND room_id = ? AND %(bounds)s"
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|             " ORDER BY topological_ordering %(order)s,"
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|             " stream_ordering %(order)s %(limit)s"
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|         ) % {
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|             "bounds": bounds,
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|             "order": order,
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|             "limit": limit_str
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|         }
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| 
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|         def f(txn):
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|             txn.execute(sql, args)
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| 
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|             rows = self.cursor_to_dict(txn)
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| 
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|             if rows:
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|                 topo = rows[-1]["topological_ordering"]
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|                 toke = rows[-1]["stream_ordering"]
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|                 if direction == 'b':
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|                     # Tokens are positions between events.
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|                     # This token points *after* the last event in the chunk.
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|                     # We need it to point to the event before it in the chunk
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|                     # when we are going backwards so we subtract one from the
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|                     # stream part.
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|                     toke -= 1
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|                 next_token = str(RoomStreamToken(topo, toke))
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|             else:
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|                 # TODO (erikj): We should work out what to do here instead.
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|                 next_token = to_key if to_key else from_key
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| 
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|             return rows, next_token,
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| 
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|         rows, token = yield self.runInteraction("paginate_room_events", f)
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| 
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|         events = yield self._get_events(
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|             [r["event_id"] for r in rows],
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|             get_prev_content=True
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|         )
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| 
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|         self._set_before_and_after(events, rows)
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| 
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|         defer.returnValue((events, token))
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| 
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|     @cachedInlineCallbacks(num_args=4)
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|     def get_recent_events_for_room(self, room_id, limit, end_token, from_token=None):
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| 
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|         end_token = RoomStreamToken.parse_stream_token(end_token)
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| 
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|         if from_token is None:
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|             sql = (
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|                 "SELECT stream_ordering, topological_ordering, event_id"
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|                 " FROM events"
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|                 " WHERE room_id = ? AND stream_ordering <= ? AND outlier = ?"
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|                 " ORDER BY topological_ordering DESC, stream_ordering DESC"
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|                 " LIMIT ?"
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|             )
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|         else:
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|             from_token = RoomStreamToken.parse_stream_token(from_token)
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|             sql = (
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|                 "SELECT stream_ordering, topological_ordering, event_id"
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|                 " FROM events"
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|                 " WHERE room_id = ? AND stream_ordering > ?"
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|                 " AND stream_ordering <= ? AND outlier = ?"
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|                 " ORDER BY topological_ordering DESC, stream_ordering DESC"
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|                 " LIMIT ?"
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|             )
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| 
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|         def get_recent_events_for_room_txn(txn):
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|             if from_token is None:
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|                 txn.execute(sql, (room_id, end_token.stream, False, limit,))
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|             else:
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|                 txn.execute(sql, (
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|                     room_id, from_token.stream, end_token.stream, False, limit
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|                 ))
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| 
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|             rows = self.cursor_to_dict(txn)
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| 
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|             rows.reverse()  # As we selected with reverse ordering
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| 
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|             if rows:
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|                 # Tokens are positions between events.
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|                 # This token points *after* the last event in the chunk.
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|                 # We need it to point to the event before it in the chunk
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|                 # since we are going backwards so we subtract one from the
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|                 # stream part.
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|                 topo = rows[0]["topological_ordering"]
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|                 toke = rows[0]["stream_ordering"] - 1
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|                 start_token = str(RoomStreamToken(topo, toke))
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| 
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|                 token = (start_token, str(end_token))
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|             else:
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|                 token = (str(end_token), str(end_token))
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| 
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|             return rows, token
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| 
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|         rows, token = yield self.runInteraction(
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|             "get_recent_events_for_room", get_recent_events_for_room_txn
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|         )
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| 
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|         logger.debug("stream before")
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|         events = yield self._get_events(
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|             [r["event_id"] for r in rows],
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|             get_prev_content=True
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|         )
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|         logger.debug("stream after")
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| 
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|         self._set_before_and_after(events, rows)
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| 
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|         defer.returnValue((events, token))
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| 
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|     @defer.inlineCallbacks
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|     def get_room_events_max_id(self, direction='f'):
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|         token = yield self._stream_id_gen.get_max_token(self)
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|         if direction != 'b':
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|             defer.returnValue("s%d" % (token,))
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|         else:
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|             topo = yield self.runInteraction(
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|                 "_get_max_topological_txn", self._get_max_topological_txn
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|             )
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|             defer.returnValue("t%d-%d" % (topo, token))
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| 
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|     def get_stream_token_for_event(self, event_id):
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|         """The stream token for an event
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|         Args:
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|             event_id(str): The id of the event to look up a stream token for.
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|         Raises:
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|             StoreError if the event wasn't in the database.
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|         Returns:
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|             A deferred "s%d" stream token.
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|         """
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|         return self._simple_select_one_onecol(
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|             table="events",
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|             keyvalues={"event_id": event_id},
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|             retcol="stream_ordering",
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|         ).addCallback(lambda row: "s%d" % (row,))
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| 
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|     def get_topological_token_for_event(self, event_id):
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|         """The stream token for an event
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|         Args:
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|             event_id(str): The id of the event to look up a stream token for.
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|         Raises:
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|             StoreError if the event wasn't in the database.
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|         Returns:
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|             A deferred "t%d-%d" topological token.
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|         """
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|         return self._simple_select_one(
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|             table="events",
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|             keyvalues={"event_id": event_id},
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|             retcols=("stream_ordering", "topological_ordering"),
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|         ).addCallback(lambda row: "t%d-%d" % (
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|             row["topological_ordering"], row["stream_ordering"],)
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|         )
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| 
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|     def _get_max_topological_txn(self, txn):
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|         txn.execute(
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|             "SELECT MAX(topological_ordering) FROM events"
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|             " WHERE outlier = ?",
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|             (False,)
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|         )
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| 
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|         rows = txn.fetchall()
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|         return rows[0][0] if rows else 0
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| 
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|     @defer.inlineCallbacks
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|     def _get_min_token(self):
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|         row = yield self._execute(
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|             "_get_min_token", None, "SELECT MIN(stream_ordering) FROM events"
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|         )
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| 
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|         self.min_token = row[0][0] if row and row[0] and row[0][0] else -1
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|         self.min_token = min(self.min_token, -1)
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| 
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|         logger.debug("min_token is: %s", self.min_token)
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| 
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|         defer.returnValue(self.min_token)
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| 
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|     @staticmethod
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|     def _set_before_and_after(events, rows):
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|         for event, row in zip(events, rows):
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|             stream = row["stream_ordering"]
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|             topo = event.depth
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|             internal = event.internal_metadata
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|             internal.before = str(RoomStreamToken(topo, stream - 1))
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|             internal.after = str(RoomStreamToken(topo, stream))
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| 
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|     @defer.inlineCallbacks
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|     def get_events_around(self, room_id, event_id, before_limit, after_limit):
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|         """Retrieve events and pagination tokens around a given event in a
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|         room.
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| 
 | |
|         Args:
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|             room_id (str)
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|             event_id (str)
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|             before_limit (int)
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|             after_limit (int)
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| 
 | |
|         Returns:
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|             dict
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|         """
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| 
 | |
|         results = yield self.runInteraction(
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|             "get_events_around", self._get_events_around_txn,
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|             room_id, event_id, before_limit, after_limit
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|         )
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| 
 | |
|         events_before = yield self._get_events(
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|             [e for e in results["before"]["event_ids"]],
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|             get_prev_content=True
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|         )
 | |
| 
 | |
|         events_after = yield self._get_events(
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|             [e for e in results["after"]["event_ids"]],
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|             get_prev_content=True
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|         )
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| 
 | |
|         defer.returnValue({
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|             "events_before": events_before,
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|             "events_after": events_after,
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|             "start": results["before"]["token"],
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|             "end": results["after"]["token"],
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|         })
 | |
| 
 | |
|     def _get_events_around_txn(self, txn, room_id, event_id, before_limit, after_limit):
 | |
|         """Retrieves event_ids and pagination tokens around a given event in a
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|         room.
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| 
 | |
|         Args:
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|             room_id (str)
 | |
|             event_id (str)
 | |
|             before_limit (int)
 | |
|             after_limit (int)
 | |
| 
 | |
|         Returns:
 | |
|             dict
 | |
|         """
 | |
| 
 | |
|         results = self._simple_select_one_txn(
 | |
|             txn,
 | |
|             "events",
 | |
|             keyvalues={
 | |
|                 "event_id": event_id,
 | |
|                 "room_id": room_id,
 | |
|             },
 | |
|             retcols=["stream_ordering", "topological_ordering"],
 | |
|         )
 | |
| 
 | |
|         stream_ordering = results["stream_ordering"]
 | |
|         topological_ordering = results["topological_ordering"]
 | |
| 
 | |
|         query_before = (
 | |
|             "SELECT topological_ordering, stream_ordering, event_id FROM events"
 | |
|             " WHERE room_id = ? AND (topological_ordering < ?"
 | |
|             " OR (topological_ordering = ? AND stream_ordering < ?))"
 | |
|             " ORDER BY topological_ordering DESC, stream_ordering DESC"
 | |
|             " LIMIT ?"
 | |
|         )
 | |
| 
 | |
|         query_after = (
 | |
|             "SELECT topological_ordering, stream_ordering, event_id FROM events"
 | |
|             " WHERE room_id = ? AND (topological_ordering > ?"
 | |
|             " OR (topological_ordering = ? AND stream_ordering > ?))"
 | |
|             " ORDER BY topological_ordering ASC, stream_ordering ASC"
 | |
|             " LIMIT ?"
 | |
|         )
 | |
| 
 | |
|         txn.execute(
 | |
|             query_before,
 | |
|             (
 | |
|                 room_id, topological_ordering, topological_ordering,
 | |
|                 stream_ordering, before_limit,
 | |
|             )
 | |
|         )
 | |
| 
 | |
|         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(
 | |
|                 topological_ordering,
 | |
|                 stream_ordering - 1,
 | |
|             ))
 | |
| 
 | |
|         txn.execute(
 | |
|             query_after,
 | |
|             (
 | |
|                 room_id, topological_ordering, topological_ordering,
 | |
|                 stream_ordering, after_limit,
 | |
|             )
 | |
|         )
 | |
| 
 | |
|         rows = self.cursor_to_dict(txn)
 | |
|         events_after = [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(RoomStreamToken(
 | |
|                 topological_ordering,
 | |
|                 stream_ordering,
 | |
|             ))
 | |
| 
 | |
|         return {
 | |
|             "before": {
 | |
|                 "event_ids": events_before,
 | |
|                 "token": start_token,
 | |
|             },
 | |
|             "after": {
 | |
|                 "event_ids": events_after,
 | |
|                 "token": end_token,
 | |
|             },
 | |
|         }
 |