summary refs log tree commit diff
path: root/synapse/storage/databases/main/room.py
blob: 127588ce4c4d72cd3ef3d5ebfad6cca099c55006 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
# -*- coding: utf-8 -*-
# Copyright 2014-2016 OpenMarket Ltd
# Copyright 2019 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import collections
import logging
import re
from abc import abstractmethod
from enum import Enum
from typing import Any, Dict, List, Optional, Tuple

from synapse.api.constants import EventTypes
from synapse.api.errors import StoreError
from synapse.api.room_versions import RoomVersion, RoomVersions
from synapse.storage._base import SQLBaseStore, db_to_json
from synapse.storage.database import DatabasePool, LoggingTransaction
from synapse.storage.databases.main.search import SearchStore
from synapse.types import JsonDict, ThirdPartyInstanceID
from synapse.util import json_encoder
from synapse.util.caches.descriptors import cached

logger = logging.getLogger(__name__)


RatelimitOverride = collections.namedtuple(
    "RatelimitOverride", ("messages_per_second", "burst_count")
)


class RoomSortOrder(Enum):
    """
    Enum to define the sorting method used when returning rooms with get_rooms_paginate

    NAME = sort rooms alphabetically by name
    JOINED_MEMBERS = sort rooms by membership size, highest to lowest
    """

    # ALPHABETICAL and SIZE are deprecated.
    # ALPHABETICAL is the same as NAME.
    ALPHABETICAL = "alphabetical"
    # SIZE is the same as JOINED_MEMBERS.
    SIZE = "size"
    NAME = "name"
    CANONICAL_ALIAS = "canonical_alias"
    JOINED_MEMBERS = "joined_members"
    JOINED_LOCAL_MEMBERS = "joined_local_members"
    VERSION = "version"
    CREATOR = "creator"
    ENCRYPTION = "encryption"
    FEDERATABLE = "federatable"
    PUBLIC = "public"
    JOIN_RULES = "join_rules"
    GUEST_ACCESS = "guest_access"
    HISTORY_VISIBILITY = "history_visibility"
    STATE_EVENTS = "state_events"


class RoomWorkerStore(SQLBaseStore):
    def __init__(self, database: DatabasePool, db_conn, hs):
        super(RoomWorkerStore, self).__init__(database, db_conn, hs)

        self.config = hs.config

    async def get_room(self, room_id: str) -> dict:
        """Retrieve a room.

        Args:
            room_id: The ID of the room to retrieve.
        Returns:
            A dict containing the room information, or None if the room is unknown.
        """
        return await self.db_pool.simple_select_one(
            table="rooms",
            keyvalues={"room_id": room_id},
            retcols=("room_id", "is_public", "creator"),
            desc="get_room",
            allow_none=True,
        )

    async def get_room_with_stats(self, room_id: str) -> Optional[Dict[str, Any]]:
        """Retrieve room with statistics.

        Args:
            room_id: The ID of the room to retrieve.
        Returns:
            A dict containing the room information, or None if the room is unknown.
        """

        def get_room_with_stats_txn(txn, room_id):
            sql = """
                SELECT room_id, state.name, state.canonical_alias, curr.joined_members,
                  curr.local_users_in_room AS joined_local_members, rooms.room_version AS version,
                  rooms.creator, state.encryption, state.is_federatable AS federatable,
                  rooms.is_public AS public, state.join_rules, state.guest_access,
                  state.history_visibility, curr.current_state_events AS state_events,
                  state.avatar, state.topic
                FROM rooms
                LEFT JOIN room_stats_state state USING (room_id)
                LEFT JOIN room_stats_current curr USING (room_id)
                WHERE room_id = ?
                """
            txn.execute(sql, [room_id])
            # Catch error if sql returns empty result to return "None" instead of an error
            try:
                res = self.db_pool.cursor_to_dict(txn)[0]
            except IndexError:
                return None

            res["federatable"] = bool(res["federatable"])
            res["public"] = bool(res["public"])
            return res

        return await self.db_pool.runInteraction(
            "get_room_with_stats", get_room_with_stats_txn, room_id
        )

    async def get_public_room_ids(self) -> List[str]:
        return await self.db_pool.simple_select_onecol(
            table="rooms",
            keyvalues={"is_public": True},
            retcol="room_id",
            desc="get_public_room_ids",
        )

    async def count_public_rooms(
        self,
        network_tuple: Optional[ThirdPartyInstanceID],
        ignore_non_federatable: bool,
    ) -> int:
        """Counts the number of public rooms as tracked in the room_stats_current
        and room_stats_state table.

        Args:
            network_tuple
            ignore_non_federatable: If true filters out non-federatable rooms
        """

        def _count_public_rooms_txn(txn):
            query_args = []

            if network_tuple:
                if network_tuple.appservice_id:
                    published_sql = """
                        SELECT room_id from appservice_room_list
                        WHERE appservice_id = ? AND network_id = ?
                    """
                    query_args.append(network_tuple.appservice_id)
                    query_args.append(network_tuple.network_id)
                else:
                    published_sql = """
                        SELECT room_id FROM rooms WHERE is_public
                    """
            else:
                published_sql = """
                    SELECT room_id FROM rooms WHERE is_public
                    UNION SELECT room_id from appservice_room_list
            """

            sql = """
                SELECT
                    COALESCE(COUNT(*), 0)
                FROM (
                    %(published_sql)s
                ) published
                INNER JOIN room_stats_state USING (room_id)
                INNER JOIN room_stats_current USING (room_id)
                WHERE
                    (
                        join_rules = 'public' OR history_visibility = 'world_readable'
                    )
                    AND joined_members > 0
            """ % {
                "published_sql": published_sql
            }

            txn.execute(sql, query_args)
            return txn.fetchone()[0]

        return await self.db_pool.runInteraction(
            "count_public_rooms", _count_public_rooms_txn
        )

    async def get_largest_public_rooms(
        self,
        network_tuple: Optional[ThirdPartyInstanceID],
        search_filter: Optional[dict],
        limit: Optional[int],
        bounds: Optional[Tuple[int, str]],
        forwards: bool,
        ignore_non_federatable: bool = False,
    ):
        """Gets the largest public rooms (where largest is in terms of joined
        members, as tracked in the statistics table).

        Args:
            network_tuple
            search_filter
            limit: Maxmimum number of rows to return, unlimited otherwise.
            bounds: An uppoer or lower bound to apply to result set if given,
                consists of a joined member count and room_id (these are
                excluded from result set).
            forwards: true iff going forwards, going backwards otherwise
            ignore_non_federatable: If true filters out non-federatable rooms.

        Returns:
            Rooms in order: biggest number of joined users first.
            We then arbitrarily use the room_id as a tie breaker.

        """

        where_clauses = []
        query_args = []

        if network_tuple:
            if network_tuple.appservice_id:
                published_sql = """
                    SELECT room_id from appservice_room_list
                    WHERE appservice_id = ? AND network_id = ?
                """
                query_args.append(network_tuple.appservice_id)
                query_args.append(network_tuple.network_id)
            else:
                published_sql = """
                    SELECT room_id FROM rooms WHERE is_public
                """
        else:
            published_sql = """
                SELECT room_id FROM rooms WHERE is_public
                UNION SELECT room_id from appservice_room_list
            """

        # Work out the bounds if we're given them, these bounds look slightly
        # odd, but are designed to help query planner use indices by pulling
        # out a common bound.
        if bounds:
            last_joined_members, last_room_id = bounds
            if forwards:
                where_clauses.append(
                    """
                        joined_members <= ? AND (
                            joined_members < ? OR room_id < ?
                        )
                    """
                )
            else:
                where_clauses.append(
                    """
                        joined_members >= ? AND (
                            joined_members > ? OR room_id > ?
                        )
                    """
                )

            query_args += [last_joined_members, last_joined_members, last_room_id]

        if ignore_non_federatable:
            where_clauses.append("is_federatable")

        if search_filter and search_filter.get("generic_search_term", None):
            search_term = "%" + search_filter["generic_search_term"] + "%"

            where_clauses.append(
                """
                    (
                        LOWER(name) LIKE ?
                        OR LOWER(topic) LIKE ?
                        OR LOWER(canonical_alias) LIKE ?
                    )
                """
            )
            query_args += [
                search_term.lower(),
                search_term.lower(),
                search_term.lower(),
            ]

        where_clause = ""
        if where_clauses:
            where_clause = " AND " + " AND ".join(where_clauses)

        sql = """
            SELECT
                room_id, name, topic, canonical_alias, joined_members,
                avatar, history_visibility, joined_members, guest_access
            FROM (
                %(published_sql)s
            ) published
            INNER JOIN room_stats_state USING (room_id)
            INNER JOIN room_stats_current USING (room_id)
            WHERE
                (
                    join_rules = 'public' OR history_visibility = 'world_readable'
                )
                AND joined_members > 0
                %(where_clause)s
            ORDER BY joined_members %(dir)s, room_id %(dir)s
        """ % {
            "published_sql": published_sql,
            "where_clause": where_clause,
            "dir": "DESC" if forwards else "ASC",
        }

        if limit is not None:
            query_args.append(limit)

            sql += """
                LIMIT ?
            """

        def _get_largest_public_rooms_txn(txn):
            txn.execute(sql, query_args)

            results = self.db_pool.cursor_to_dict(txn)

            if not forwards:
                results.reverse()

            return results

        ret_val = await self.db_pool.runInteraction(
            "get_largest_public_rooms", _get_largest_public_rooms_txn
        )
        return ret_val

    @cached(max_entries=10000)
    async def is_room_blocked(self, room_id: str) -> Optional[bool]:
        return await self.db_pool.simple_select_one_onecol(
            table="blocked_rooms",
            keyvalues={"room_id": room_id},
            retcol="1",
            allow_none=True,
            desc="is_room_blocked",
        )

    async def get_rooms_paginate(
        self,
        start: int,
        limit: int,
        order_by: RoomSortOrder,
        reverse_order: bool,
        search_term: Optional[str],
    ) -> Tuple[List[Dict[str, Any]], int]:
        """Function to retrieve a paginated list of rooms as json.

        Args:
            start: offset in the list
            limit: maximum amount of rooms to retrieve
            order_by: the sort order of the returned list
            reverse_order: whether to reverse the room list
            search_term: a string to filter room names by
        Returns:
            A list of room dicts and an integer representing the total number of
            rooms that exist given this query
        """
        # Filter room names by a string
        where_statement = ""
        if search_term:
            where_statement = "WHERE state.name LIKE ?"

            # Our postgres db driver converts ? -> %s in SQL strings as that's the
            # placeholder for postgres.
            # HOWEVER, if you put a % into your SQL then everything goes wibbly.
            # To get around this, we're going to surround search_term with %'s
            # before giving it to the database in python instead
            search_term = "%" + search_term + "%"

        # Set ordering
        if RoomSortOrder(order_by) == RoomSortOrder.SIZE:
            # Deprecated in favour of RoomSortOrder.JOINED_MEMBERS
            order_by_column = "curr.joined_members"
            order_by_asc = False
        elif RoomSortOrder(order_by) == RoomSortOrder.ALPHABETICAL:
            # Deprecated in favour of RoomSortOrder.NAME
            order_by_column = "state.name"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.NAME:
            order_by_column = "state.name"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.CANONICAL_ALIAS:
            order_by_column = "state.canonical_alias"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.JOINED_MEMBERS:
            order_by_column = "curr.joined_members"
            order_by_asc = False
        elif RoomSortOrder(order_by) == RoomSortOrder.JOINED_LOCAL_MEMBERS:
            order_by_column = "curr.local_users_in_room"
            order_by_asc = False
        elif RoomSortOrder(order_by) == RoomSortOrder.VERSION:
            order_by_column = "rooms.room_version"
            order_by_asc = False
        elif RoomSortOrder(order_by) == RoomSortOrder.CREATOR:
            order_by_column = "rooms.creator"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.ENCRYPTION:
            order_by_column = "state.encryption"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.FEDERATABLE:
            order_by_column = "state.is_federatable"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.PUBLIC:
            order_by_column = "rooms.is_public"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.JOIN_RULES:
            order_by_column = "state.join_rules"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.GUEST_ACCESS:
            order_by_column = "state.guest_access"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.HISTORY_VISIBILITY:
            order_by_column = "state.history_visibility"
            order_by_asc = True
        elif RoomSortOrder(order_by) == RoomSortOrder.STATE_EVENTS:
            order_by_column = "curr.current_state_events"
            order_by_asc = False
        else:
            raise StoreError(
                500, "Incorrect value for order_by provided: %s" % order_by
            )

        # Whether to return the list in reverse order
        if reverse_order:
            # Flip the boolean
            order_by_asc = not order_by_asc

        # Create one query for getting the limited number of events that the user asked
        # for, and another query for getting the total number of events that could be
        # returned. Thus allowing us to see if there are more events to paginate through
        info_sql = """
            SELECT state.room_id, state.name, state.canonical_alias, curr.joined_members,
              curr.local_users_in_room, rooms.room_version, rooms.creator,
              state.encryption, state.is_federatable, rooms.is_public, state.join_rules,
              state.guest_access, state.history_visibility, curr.current_state_events
            FROM room_stats_state state
            INNER JOIN room_stats_current curr USING (room_id)
            INNER JOIN rooms USING (room_id)
            %s
            ORDER BY %s %s
            LIMIT ?
            OFFSET ?
        """ % (
            where_statement,
            order_by_column,
            "ASC" if order_by_asc else "DESC",
        )

        # Use a nested SELECT statement as SQL can't count(*) with an OFFSET
        count_sql = """
            SELECT count(*) FROM (
              SELECT room_id FROM room_stats_state state
              %s
            ) AS get_room_ids
        """ % (
            where_statement,
        )

        def _get_rooms_paginate_txn(txn):
            # Execute the data query
            sql_values = (limit, start)
            if search_term:
                # Add the search term into the WHERE clause
                sql_values = (search_term,) + sql_values
            txn.execute(info_sql, sql_values)

            # Refactor room query data into a structured dictionary
            rooms = []
            for room in txn:
                rooms.append(
                    {
                        "room_id": room[0],
                        "name": room[1],
                        "canonical_alias": room[2],
                        "joined_members": room[3],
                        "joined_local_members": room[4],
                        "version": room[5],
                        "creator": room[6],
                        "encryption": room[7],
                        "federatable": room[8],
                        "public": room[9],
                        "join_rules": room[10],
                        "guest_access": room[11],
                        "history_visibility": room[12],
                        "state_events": room[13],
                    }
                )

            # Execute the count query

            # Add the search term into the WHERE clause if present
            sql_values = (search_term,) if search_term else ()
            txn.execute(count_sql, sql_values)

            room_count = txn.fetchone()
            return rooms, room_count[0]

        return await self.db_pool.runInteraction(
            "get_rooms_paginate", _get_rooms_paginate_txn,
        )

    @cached(max_entries=10000)
    async def get_ratelimit_for_user(self, user_id):
        """Check if there are any overrides for ratelimiting for the given
        user

        Args:
            user_id (str)

        Returns:
            RatelimitOverride if there is an override, else None. If the contents
            of RatelimitOverride are None or 0 then ratelimitng has been
            disabled for that user entirely.
        """
        row = await self.db_pool.simple_select_one(
            table="ratelimit_override",
            keyvalues={"user_id": user_id},
            retcols=("messages_per_second", "burst_count"),
            allow_none=True,
            desc="get_ratelimit_for_user",
        )

        if row:
            return RatelimitOverride(
                messages_per_second=row["messages_per_second"],
                burst_count=row["burst_count"],
            )
        else:
            return None

    @cached()
    async def get_retention_policy_for_room(self, room_id):
        """Get the retention policy for a given room.

        If no retention policy has been found for this room, returns a policy defined
        by the configured default policy (which has None as both the 'min_lifetime' and
        the 'max_lifetime' if no default policy has been defined in the server's
        configuration).

        Args:
            room_id (str): The ID of the room to get the retention policy of.

        Returns:
            dict[int, int]: "min_lifetime" and "max_lifetime" for this room.
        """

        def get_retention_policy_for_room_txn(txn):
            txn.execute(
                """
                SELECT min_lifetime, max_lifetime FROM room_retention
                INNER JOIN current_state_events USING (event_id, room_id)
                WHERE room_id = ?;
                """,
                (room_id,),
            )

            return self.db_pool.cursor_to_dict(txn)

        ret = await self.db_pool.runInteraction(
            "get_retention_policy_for_room", get_retention_policy_for_room_txn,
        )

        # If we don't know this room ID, ret will be None, in this case return the default
        # policy.
        if not ret:
            return {
                "min_lifetime": self.config.retention_default_min_lifetime,
                "max_lifetime": self.config.retention_default_max_lifetime,
            }

        row = ret[0]

        # If one of the room's policy's attributes isn't defined, use the matching
        # attribute from the default policy.
        # The default values will be None if no default policy has been defined, or if one
        # of the attributes is missing from the default policy.
        if row["min_lifetime"] is None:
            row["min_lifetime"] = self.config.retention_default_min_lifetime

        if row["max_lifetime"] is None:
            row["max_lifetime"] = self.config.retention_default_max_lifetime

        return row

    async def get_media_mxcs_in_room(self, room_id: str) -> Tuple[List[str], List[str]]:
        """Retrieves all the local and remote media MXC URIs in a given room

        Args:
            room_id

        Returns:
            The local and remote media as a lists of the media IDs.
        """

        def _get_media_mxcs_in_room_txn(txn):
            local_mxcs, remote_mxcs = self._get_media_mxcs_in_room_txn(txn, room_id)
            local_media_mxcs = []
            remote_media_mxcs = []

            # Convert the IDs to MXC URIs
            for media_id in local_mxcs:
                local_media_mxcs.append("mxc://%s/%s" % (self.hs.hostname, media_id))
            for hostname, media_id in remote_mxcs:
                remote_media_mxcs.append("mxc://%s/%s" % (hostname, media_id))

            return local_media_mxcs, remote_media_mxcs

        return await self.db_pool.runInteraction(
            "get_media_ids_in_room", _get_media_mxcs_in_room_txn
        )

    async def quarantine_media_ids_in_room(
        self, room_id: str, quarantined_by: str
    ) -> int:
        """For a room loops through all events with media and quarantines
        the associated media
        """

        logger.info("Quarantining media in room: %s", room_id)

        def _quarantine_media_in_room_txn(txn):
            local_mxcs, remote_mxcs = self._get_media_mxcs_in_room_txn(txn, room_id)
            return self._quarantine_media_txn(
                txn, local_mxcs, remote_mxcs, quarantined_by
            )

        return await self.db_pool.runInteraction(
            "quarantine_media_in_room", _quarantine_media_in_room_txn
        )

    def _get_media_mxcs_in_room_txn(self, txn, room_id):
        """Retrieves all the local and remote media MXC URIs in a given room

        Args:
            txn (cursor)
            room_id (str)

        Returns:
            The local and remote media as a lists of tuples where the key is
            the hostname and the value is the media ID.
        """
        mxc_re = re.compile("^mxc://([^/]+)/([^/#?]+)")

        sql = """
            SELECT stream_ordering, json FROM events
            JOIN event_json USING (room_id, event_id)
            WHERE room_id = ?
                %(where_clause)s
                AND contains_url = ? AND outlier = ?
            ORDER BY stream_ordering DESC
            LIMIT ?
        """
        txn.execute(sql % {"where_clause": ""}, (room_id, True, False, 100))

        local_media_mxcs = []
        remote_media_mxcs = []

        while True:
            next_token = None
            for stream_ordering, content_json in txn:
                next_token = stream_ordering
                event_json = db_to_json(content_json)
                content = event_json["content"]
                content_url = content.get("url")
                thumbnail_url = content.get("info", {}).get("thumbnail_url")

                for url in (content_url, thumbnail_url):
                    if not url:
                        continue
                    matches = mxc_re.match(url)
                    if matches:
                        hostname = matches.group(1)
                        media_id = matches.group(2)
                        if hostname == self.hs.hostname:
                            local_media_mxcs.append(media_id)
                        else:
                            remote_media_mxcs.append((hostname, media_id))

            if next_token is None:
                # We've gone through the whole room, so we're finished.
                break

            txn.execute(
                sql % {"where_clause": "AND stream_ordering < ?"},
                (room_id, next_token, True, False, 100),
            )

        return local_media_mxcs, remote_media_mxcs

    async def quarantine_media_by_id(
        self, server_name: str, media_id: str, quarantined_by: str,
    ) -> int:
        """quarantines a single local or remote media id

        Args:
            server_name: The name of the server that holds this media
            media_id: The ID of the media to be quarantined
            quarantined_by: The user ID that initiated the quarantine request
        """
        logger.info("Quarantining media: %s/%s", server_name, media_id)
        is_local = server_name == self.config.server_name

        def _quarantine_media_by_id_txn(txn):
            local_mxcs = [media_id] if is_local else []
            remote_mxcs = [(server_name, media_id)] if not is_local else []

            return self._quarantine_media_txn(
                txn, local_mxcs, remote_mxcs, quarantined_by
            )

        return await self.db_pool.runInteraction(
            "quarantine_media_by_user", _quarantine_media_by_id_txn
        )

    async def quarantine_media_ids_by_user(
        self, user_id: str, quarantined_by: str
    ) -> int:
        """quarantines all local media associated with a single user

        Args:
            user_id: The ID of the user to quarantine media of
            quarantined_by: The ID of the user who made the quarantine request
        """

        def _quarantine_media_by_user_txn(txn):
            local_media_ids = self._get_media_ids_by_user_txn(txn, user_id)
            return self._quarantine_media_txn(txn, local_media_ids, [], quarantined_by)

        return await self.db_pool.runInteraction(
            "quarantine_media_by_user", _quarantine_media_by_user_txn
        )

    def _get_media_ids_by_user_txn(self, txn, user_id: str, filter_quarantined=True):
        """Retrieves local media IDs by a given user

        Args:
            txn (cursor)
            user_id: The ID of the user to retrieve media IDs of

        Returns:
            The local and remote media as a lists of tuples where the key is
            the hostname and the value is the media ID.
        """
        # Local media
        sql = """
            SELECT media_id
            FROM local_media_repository
            WHERE user_id = ?
            """
        if filter_quarantined:
            sql += "AND quarantined_by IS NULL"
        txn.execute(sql, (user_id,))

        local_media_ids = [row[0] for row in txn]

        # TODO: Figure out all remote media a user has referenced in a message

        return local_media_ids

    def _quarantine_media_txn(
        self,
        txn,
        local_mxcs: List[str],
        remote_mxcs: List[Tuple[str, str]],
        quarantined_by: str,
    ) -> int:
        """Quarantine local and remote media items

        Args:
            txn (cursor)
            local_mxcs: A list of local mxc URLs
            remote_mxcs: A list of (remote server, media id) tuples representing
                remote mxc URLs
            quarantined_by: The ID of the user who initiated the quarantine request
        Returns:
            The total number of media items quarantined
        """
        # Update all the tables to set the quarantined_by flag
        txn.executemany(
            """
            UPDATE local_media_repository
            SET quarantined_by = ?
            WHERE media_id = ? AND safe_from_quarantine = ?
        """,
            ((quarantined_by, media_id, False) for media_id in local_mxcs),
        )
        # Note that a rowcount of -1 can be used to indicate no rows were affected.
        total_media_quarantined = txn.rowcount if txn.rowcount > 0 else 0

        txn.executemany(
            """
                UPDATE remote_media_cache
                SET quarantined_by = ?
                WHERE media_origin = ? AND media_id = ?
            """,
            ((quarantined_by, origin, media_id) for origin, media_id in remote_mxcs),
        )
        total_media_quarantined += txn.rowcount if txn.rowcount > 0 else 0

        return total_media_quarantined

    async def get_all_new_public_rooms(
        self, instance_name: str, last_id: int, current_id: int, limit: int
    ) -> Tuple[List[Tuple[int, tuple]], int, bool]:
        """Get updates for public rooms replication stream.

        Args:
            instance_name: The writer we want to fetch updates from. Unused
                here since there is only ever one writer.
            last_id: The token to fetch updates from. Exclusive.
            current_id: The token to fetch updates up to. Inclusive.
            limit: The requested limit for the number of rows to return. The
                function may return more or fewer rows.

        Returns:
            A tuple consisting of: the updates, a token to use to fetch
            subsequent updates, and whether we returned fewer rows than exists
            between the requested tokens due to the limit.

            The token returned can be used in a subsequent call to this
            function to get further updatees.

            The updates are a list of 2-tuples of stream ID and the row data
        """
        if last_id == current_id:
            return [], current_id, False

        def get_all_new_public_rooms(txn):
            sql = """
                SELECT stream_id, room_id, visibility, appservice_id, network_id
                FROM public_room_list_stream
                WHERE stream_id > ? AND stream_id <= ?
                ORDER BY stream_id ASC
                LIMIT ?
            """

            txn.execute(sql, (last_id, current_id, limit))
            updates = [(row[0], row[1:]) for row in txn]
            limited = False
            upto_token = current_id
            if len(updates) >= limit:
                upto_token = updates[-1][0]
                limited = True

            return updates, upto_token, limited

        return await self.db_pool.runInteraction(
            "get_all_new_public_rooms", get_all_new_public_rooms
        )


class RoomBackgroundUpdateStore(SQLBaseStore):
    REMOVE_TOMESTONED_ROOMS_BG_UPDATE = "remove_tombstoned_rooms_from_directory"
    ADD_ROOMS_ROOM_VERSION_COLUMN = "add_rooms_room_version_column"

    def __init__(self, database: DatabasePool, db_conn, hs):
        super(RoomBackgroundUpdateStore, self).__init__(database, db_conn, hs)

        self.config = hs.config

        self.db_pool.updates.register_background_update_handler(
            "insert_room_retention", self._background_insert_retention,
        )

        self.db_pool.updates.register_background_update_handler(
            self.REMOVE_TOMESTONED_ROOMS_BG_UPDATE,
            self._remove_tombstoned_rooms_from_directory,
        )

        self.db_pool.updates.register_background_update_handler(
            self.ADD_ROOMS_ROOM_VERSION_COLUMN,
            self._background_add_rooms_room_version_column,
        )

    async def _background_insert_retention(self, progress, batch_size):
        """Retrieves a list of all rooms within a range and inserts an entry for each of
        them into the room_retention table.
        NULLs the property's columns if missing from the retention event in the room's
        state (or NULLs all of them if there's no retention event in the room's state),
        so that we fall back to the server's retention policy.
        """

        last_room = progress.get("room_id", "")

        def _background_insert_retention_txn(txn):
            txn.execute(
                """
                SELECT state.room_id, state.event_id, events.json
                FROM current_state_events as state
                LEFT JOIN event_json AS events ON (state.event_id = events.event_id)
                WHERE state.room_id > ? AND state.type = '%s'
                ORDER BY state.room_id ASC
                LIMIT ?;
                """
                % EventTypes.Retention,
                (last_room, batch_size),
            )

            rows = self.db_pool.cursor_to_dict(txn)

            if not rows:
                return True

            for row in rows:
                if not row["json"]:
                    retention_policy = {}
                else:
                    ev = db_to_json(row["json"])
                    retention_policy = ev["content"]

                self.db_pool.simple_insert_txn(
                    txn=txn,
                    table="room_retention",
                    values={
                        "room_id": row["room_id"],
                        "event_id": row["event_id"],
                        "min_lifetime": retention_policy.get("min_lifetime"),
                        "max_lifetime": retention_policy.get("max_lifetime"),
                    },
                )

            logger.info("Inserted %d rows into room_retention", len(rows))

            self.db_pool.updates._background_update_progress_txn(
                txn, "insert_room_retention", {"room_id": rows[-1]["room_id"]}
            )

            if batch_size > len(rows):
                return True
            else:
                return False

        end = await self.db_pool.runInteraction(
            "insert_room_retention", _background_insert_retention_txn,
        )

        if end:
            await self.db_pool.updates._end_background_update("insert_room_retention")

        return batch_size

    async def _background_add_rooms_room_version_column(
        self, progress: dict, batch_size: int
    ):
        """Background update to go and add room version inforamtion to `rooms`
        table from `current_state_events` table.
        """

        last_room_id = progress.get("room_id", "")

        def _background_add_rooms_room_version_column_txn(txn: LoggingTransaction):
            sql = """
                SELECT room_id, json FROM current_state_events
                INNER JOIN event_json USING (room_id, event_id)
                WHERE room_id > ? AND type = 'm.room.create' AND state_key = ''
                ORDER BY room_id
                LIMIT ?
            """

            txn.execute(sql, (last_room_id, batch_size))

            updates = []
            for room_id, event_json in txn:
                event_dict = db_to_json(event_json)
                room_version_id = event_dict.get("content", {}).get(
                    "room_version", RoomVersions.V1.identifier
                )

                creator = event_dict.get("content").get("creator")

                updates.append((room_id, creator, room_version_id))

            if not updates:
                return True

            new_last_room_id = ""
            for room_id, creator, room_version_id in updates:
                # We upsert here just in case we don't already have a row,
                # mainly for paranoia as much badness would happen if we don't
                # insert the row and then try and get the room version for the
                # room.
                self.db_pool.simple_upsert_txn(
                    txn,
                    table="rooms",
                    keyvalues={"room_id": room_id},
                    values={"room_version": room_version_id},
                    insertion_values={"is_public": False, "creator": creator},
                )
                new_last_room_id = room_id

            self.db_pool.updates._background_update_progress_txn(
                txn, self.ADD_ROOMS_ROOM_VERSION_COLUMN, {"room_id": new_last_room_id}
            )

            return False

        end = await self.db_pool.runInteraction(
            "_background_add_rooms_room_version_column",
            _background_add_rooms_room_version_column_txn,
        )

        if end:
            await self.db_pool.updates._end_background_update(
                self.ADD_ROOMS_ROOM_VERSION_COLUMN
            )

        return batch_size

    async def _remove_tombstoned_rooms_from_directory(
        self, progress, batch_size
    ) -> int:
        """Removes any rooms with tombstone events from the room directory

        Nowadays this is handled by the room upgrade handler, but we may have some
        that got left behind
        """

        last_room = progress.get("room_id", "")

        def _get_rooms(txn):
            txn.execute(
                """
                SELECT room_id
                FROM rooms r
                INNER JOIN current_state_events cse USING (room_id)
                WHERE room_id > ? AND r.is_public
                AND cse.type = '%s' AND cse.state_key = ''
                ORDER BY room_id ASC
                LIMIT ?;
                """
                % EventTypes.Tombstone,
                (last_room, batch_size),
            )

            return [row[0] for row in txn]

        rooms = await self.db_pool.runInteraction(
            "get_tombstoned_directory_rooms", _get_rooms
        )

        if not rooms:
            await self.db_pool.updates._end_background_update(
                self.REMOVE_TOMESTONED_ROOMS_BG_UPDATE
            )
            return 0

        for room_id in rooms:
            logger.info("Removing tombstoned room %s from the directory", room_id)
            await self.set_room_is_public(room_id, False)

        await self.db_pool.updates._background_update_progress(
            self.REMOVE_TOMESTONED_ROOMS_BG_UPDATE, {"room_id": rooms[-1]}
        )

        return len(rooms)

    @abstractmethod
    def set_room_is_public(self, room_id, is_public):
        # this will need to be implemented if a background update is performed with
        # existing (tombstoned, public) rooms in the database.
        #
        # It's overridden by RoomStore for the synapse master.
        raise NotImplementedError()


class RoomStore(RoomBackgroundUpdateStore, RoomWorkerStore, SearchStore):
    def __init__(self, database: DatabasePool, db_conn, hs):
        super(RoomStore, self).__init__(database, db_conn, hs)

        self.config = hs.config

    async def upsert_room_on_join(self, room_id: str, room_version: RoomVersion):
        """Ensure that the room is stored in the table

        Called when we join a room over federation, and overwrites any room version
        currently in the table.
        """
        await self.db_pool.simple_upsert(
            desc="upsert_room_on_join",
            table="rooms",
            keyvalues={"room_id": room_id},
            values={"room_version": room_version.identifier},
            insertion_values={"is_public": False, "creator": ""},
            # rooms has a unique constraint on room_id, so no need to lock when doing an
            # emulated upsert.
            lock=False,
        )

    async def store_room(
        self,
        room_id: str,
        room_creator_user_id: str,
        is_public: bool,
        room_version: RoomVersion,
    ):
        """Stores a room.

        Args:
            room_id: The desired room ID, can be None.
            room_creator_user_id: The user ID of the room creator.
            is_public: True to indicate that this room should appear in
                public room lists.
            room_version: The version of the room
        Raises:
            StoreError if the room could not be stored.
        """
        try:

            def store_room_txn(txn, next_id):
                self.db_pool.simple_insert_txn(
                    txn,
                    "rooms",
                    {
                        "room_id": room_id,
                        "creator": room_creator_user_id,
                        "is_public": is_public,
                        "room_version": room_version.identifier,
                    },
                )
                if is_public:
                    self.db_pool.simple_insert_txn(
                        txn,
                        table="public_room_list_stream",
                        values={
                            "stream_id": next_id,
                            "room_id": room_id,
                            "visibility": is_public,
                        },
                    )

            with await self._public_room_id_gen.get_next() as next_id:
                await self.db_pool.runInteraction(
                    "store_room_txn", store_room_txn, next_id
                )
        except Exception as e:
            logger.error("store_room with room_id=%s failed: %s", room_id, e)
            raise StoreError(500, "Problem creating room.")

    async def maybe_store_room_on_invite(self, room_id: str, room_version: RoomVersion):
        """
        When we receive an invite over federation, store the version of the room if we
        don't already know the room version.
        """
        await self.db_pool.simple_upsert(
            desc="maybe_store_room_on_invite",
            table="rooms",
            keyvalues={"room_id": room_id},
            values={},
            insertion_values={
                "room_version": room_version.identifier,
                "is_public": False,
                "creator": "",
            },
            # rooms has a unique constraint on room_id, so no need to lock when doing an
            # emulated upsert.
            lock=False,
        )

    async def set_room_is_public(self, room_id, is_public):
        def set_room_is_public_txn(txn, next_id):
            self.db_pool.simple_update_one_txn(
                txn,
                table="rooms",
                keyvalues={"room_id": room_id},
                updatevalues={"is_public": is_public},
            )

            entries = self.db_pool.simple_select_list_txn(
                txn,
                table="public_room_list_stream",
                keyvalues={
                    "room_id": room_id,
                    "appservice_id": None,
                    "network_id": None,
                },
                retcols=("stream_id", "visibility"),
            )

            entries.sort(key=lambda r: r["stream_id"])

            add_to_stream = True
            if entries:
                add_to_stream = bool(entries[-1]["visibility"]) != is_public

            if add_to_stream:
                self.db_pool.simple_insert_txn(
                    txn,
                    table="public_room_list_stream",
                    values={
                        "stream_id": next_id,
                        "room_id": room_id,
                        "visibility": is_public,
                        "appservice_id": None,
                        "network_id": None,
                    },
                )

        with await self._public_room_id_gen.get_next() as next_id:
            await self.db_pool.runInteraction(
                "set_room_is_public", set_room_is_public_txn, next_id
            )
        self.hs.get_notifier().on_new_replication_data()

    async def set_room_is_public_appservice(
        self, room_id, appservice_id, network_id, is_public
    ):
        """Edit the appservice/network specific public room list.

        Each appservice can have a number of published room lists associated
        with them, keyed off of an appservice defined `network_id`, which
        basically represents a single instance of a bridge to a third party
        network.

        Args:
            room_id (str)
            appservice_id (str)
            network_id (str)
            is_public (bool): Whether to publish or unpublish the room from the
                list.
        """

        def set_room_is_public_appservice_txn(txn, next_id):
            if is_public:
                try:
                    self.db_pool.simple_insert_txn(
                        txn,
                        table="appservice_room_list",
                        values={
                            "appservice_id": appservice_id,
                            "network_id": network_id,
                            "room_id": room_id,
                        },
                    )
                except self.database_engine.module.IntegrityError:
                    # We've already inserted, nothing to do.
                    return
            else:
                self.db_pool.simple_delete_txn(
                    txn,
                    table="appservice_room_list",
                    keyvalues={
                        "appservice_id": appservice_id,
                        "network_id": network_id,
                        "room_id": room_id,
                    },
                )

            entries = self.db_pool.simple_select_list_txn(
                txn,
                table="public_room_list_stream",
                keyvalues={
                    "room_id": room_id,
                    "appservice_id": appservice_id,
                    "network_id": network_id,
                },
                retcols=("stream_id", "visibility"),
            )

            entries.sort(key=lambda r: r["stream_id"])

            add_to_stream = True
            if entries:
                add_to_stream = bool(entries[-1]["visibility"]) != is_public

            if add_to_stream:
                self.db_pool.simple_insert_txn(
                    txn,
                    table="public_room_list_stream",
                    values={
                        "stream_id": next_id,
                        "room_id": room_id,
                        "visibility": is_public,
                        "appservice_id": appservice_id,
                        "network_id": network_id,
                    },
                )

        with await self._public_room_id_gen.get_next() as next_id:
            await self.db_pool.runInteraction(
                "set_room_is_public_appservice",
                set_room_is_public_appservice_txn,
                next_id,
            )
        self.hs.get_notifier().on_new_replication_data()

    async def get_room_count(self) -> int:
        """Retrieve the total number of rooms.
        """

        def f(txn):
            sql = "SELECT count(*)  FROM rooms"
            txn.execute(sql)
            row = txn.fetchone()
            return row[0] or 0

        return await self.db_pool.runInteraction("get_rooms", f)

    async def add_event_report(
        self,
        room_id: str,
        event_id: str,
        user_id: str,
        reason: str,
        content: JsonDict,
        received_ts: int,
    ) -> None:
        next_id = self._event_reports_id_gen.get_next()
        await self.db_pool.simple_insert(
            table="event_reports",
            values={
                "id": next_id,
                "received_ts": received_ts,
                "room_id": room_id,
                "event_id": event_id,
                "user_id": user_id,
                "reason": reason,
                "content": json_encoder.encode(content),
            },
            desc="add_event_report",
        )

    def get_current_public_room_stream_id(self):
        return self._public_room_id_gen.get_current_token()

    async def block_room(self, room_id: str, user_id: str) -> None:
        """Marks the room as blocked. Can be called multiple times.

        Args:
            room_id: Room to block
            user_id: Who blocked it
        """
        await self.db_pool.simple_upsert(
            table="blocked_rooms",
            keyvalues={"room_id": room_id},
            values={},
            insertion_values={"user_id": user_id},
            desc="block_room",
        )
        await self.db_pool.runInteraction(
            "block_room_invalidation",
            self._invalidate_cache_and_stream,
            self.is_room_blocked,
            (room_id,),
        )

    async def get_rooms_for_retention_period_in_range(
        self, min_ms: Optional[int], max_ms: Optional[int], include_null: bool = False
    ) -> Dict[str, dict]:
        """Retrieves all of the rooms within the given retention range.

        Optionally includes the rooms which don't have a retention policy.

        Args:
            min_ms: Duration in milliseconds that define the lower limit of
                the range to handle (exclusive). If None, doesn't set a lower limit.
            max_ms: Duration in milliseconds that define the upper limit of
                the range to handle (inclusive). If None, doesn't set an upper limit.
            include_null: Whether to include rooms which retention policy is NULL
                in the returned set.

        Returns:
            The rooms within this range, along with their retention
            policy. The key is "room_id", and maps to a dict describing the retention
            policy associated with this room ID. The keys for this nested dict are
            "min_lifetime" (int|None), and "max_lifetime" (int|None).
        """

        def get_rooms_for_retention_period_in_range_txn(txn):
            range_conditions = []
            args = []

            if min_ms is not None:
                range_conditions.append("max_lifetime > ?")
                args.append(min_ms)

            if max_ms is not None:
                range_conditions.append("max_lifetime <= ?")
                args.append(max_ms)

            # Do a first query which will retrieve the rooms that have a retention policy
            # in their current state.
            sql = """
                SELECT room_id, min_lifetime, max_lifetime FROM room_retention
                INNER JOIN current_state_events USING (event_id, room_id)
                """

            if len(range_conditions):
                sql += " WHERE (" + " AND ".join(range_conditions) + ")"

                if include_null:
                    sql += " OR max_lifetime IS NULL"

            txn.execute(sql, args)

            rows = self.db_pool.cursor_to_dict(txn)
            rooms_dict = {}

            for row in rows:
                rooms_dict[row["room_id"]] = {
                    "min_lifetime": row["min_lifetime"],
                    "max_lifetime": row["max_lifetime"],
                }

            if include_null:
                # If required, do a second query that retrieves all of the rooms we know
                # of so we can handle rooms with no retention policy.
                sql = "SELECT DISTINCT room_id FROM current_state_events"

                txn.execute(sql)

                rows = self.db_pool.cursor_to_dict(txn)

                # If a room isn't already in the dict (i.e. it doesn't have a retention
                # policy in its state), add it with a null policy.
                for row in rows:
                    if row["room_id"] not in rooms_dict:
                        rooms_dict[row["room_id"]] = {
                            "min_lifetime": None,
                            "max_lifetime": None,
                        }

            return rooms_dict

        rooms = await self.db_pool.runInteraction(
            "get_rooms_for_retention_period_in_range",
            get_rooms_for_retention_period_in_range_txn,
        )

        return rooms