summary refs log tree commit diff
path: root/synapse/storage/databases/main/state.py
blob: eba35f37000d471fdcc57510841c8ca7616ed005 (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
# Copyright 2014-2016 OpenMarket Ltd
# Copyright 2020 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 logging
from typing import TYPE_CHECKING, Collection, Dict, Iterable, Optional, Set, Tuple

from frozendict import frozendict

from synapse.api.constants import EventTypes, Membership
from synapse.api.errors import NotFoundError, UnsupportedRoomVersionError
from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersion
from synapse.events import EventBase
from synapse.events.snapshot import EventContext
from synapse.storage._base import SQLBaseStore
from synapse.storage.database import (
    DatabasePool,
    LoggingDatabaseConnection,
    LoggingTransaction,
)
from synapse.storage.databases.main.events_worker import EventsWorkerStore
from synapse.storage.databases.main.roommember import RoomMemberWorkerStore
from synapse.storage.state import StateFilter
from synapse.types import JsonDict, JsonMapping, StateMap
from synapse.util.caches import intern_string
from synapse.util.caches.descriptors import cached, cachedList

if TYPE_CHECKING:
    from synapse.server import HomeServer

logger = logging.getLogger(__name__)


MAX_STATE_DELTA_HOPS = 100


def _retrieve_and_check_room_version(room_id: str, room_version_id: str) -> RoomVersion:
    v = KNOWN_ROOM_VERSIONS.get(room_version_id)
    if not v:
        raise UnsupportedRoomVersionError(
            "Room %s uses a room version %s which is no longer supported"
            % (room_id, room_version_id)
        )
    return v


# this inherits from EventsWorkerStore because it calls self.get_events
class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
    """The parts of StateGroupStore that can be called from workers."""

    def __init__(
        self,
        database: DatabasePool,
        db_conn: LoggingDatabaseConnection,
        hs: "HomeServer",
    ):
        super().__init__(database, db_conn, hs)

    async def get_room_version(self, room_id: str) -> RoomVersion:
        """Get the room_version of a given room
        Raises:
            NotFoundError: if the room is unknown
            UnsupportedRoomVersionError: if the room uses an unknown room version.
                Typically this happens if support for the room's version has been
                removed from Synapse.
        """
        room_version_id = await self.get_room_version_id(room_id)
        return _retrieve_and_check_room_version(room_id, room_version_id)

    def get_room_version_txn(
        self, txn: LoggingTransaction, room_id: str
    ) -> RoomVersion:
        """Get the room_version of a given room
        Args:
            txn: Transaction object
            room_id: The room_id of the room you are trying to get the version for
        Raises:
            NotFoundError: if the room is unknown
            UnsupportedRoomVersionError: if the room uses an unknown room version.
                Typically this happens if support for the room's version has been
                removed from Synapse.
        """
        room_version_id = self.get_room_version_id_txn(txn, room_id)
        return _retrieve_and_check_room_version(room_id, room_version_id)

    @cached(max_entries=10000)
    async def get_room_version_id(self, room_id: str) -> str:
        """Get the room_version of a given room
        Raises:
            NotFoundError: if the room is unknown
        """
        return await self.db_pool.runInteraction(
            "get_room_version_id_txn",
            self.get_room_version_id_txn,
            room_id,
        )

    def get_room_version_id_txn(self, txn: LoggingTransaction, room_id: str) -> str:
        """Get the room_version of a given room
        Args:
            txn: Transaction object
            room_id: The room_id of the room you are trying to get the version for
        Raises:
            NotFoundError: if the room is unknown
        """

        # First we try looking up room version from the database, but for old
        # rooms we might not have added the room version to it yet so we fall
        # back to previous behaviour and look in current state events.
        #
        # We really should have an entry in the rooms table for every room we
        # care about, but let's be a bit paranoid (at least while the background
        # update is happening) to avoid breaking existing rooms.
        room_version = self.db_pool.simple_select_one_onecol_txn(
            txn,
            table="rooms",
            keyvalues={"room_id": room_id},
            retcol="room_version",
            allow_none=True,
        )

        if room_version is None:
            raise NotFoundError("Could not room_version for %s" % (room_id,))

        return room_version

    async def get_room_predecessor(self, room_id: str) -> Optional[JsonMapping]:
        """Get the predecessor of an upgraded room if it exists.
        Otherwise return None.

        Args:
            room_id: The room ID.

        Returns:
            A dictionary containing the structure of the predecessor
            field from the room's create event. The structure is subject to other servers,
            but it is expected to be:
                * room_id (str): The room ID of the predecessor room
                * event_id (str): The ID of the tombstone event in the predecessor room

            None if a predecessor key is not found, or is not a dictionary.

        Raises:
            NotFoundError if the given room is unknown
        """
        # Retrieve the room's create event
        create_event = await self.get_create_event_for_room(room_id)

        # Retrieve the predecessor key of the create event
        predecessor = create_event.content.get("predecessor", None)

        # Ensure the key is a dictionary
        if not isinstance(predecessor, (dict, frozendict)):
            return None

        # The keys must be strings since the data is JSON.
        return predecessor

    async def get_create_event_for_room(self, room_id: str) -> EventBase:
        """Get the create state event for a room.

        Args:
            room_id: The room ID.

        Returns:
            The room creation event.

        Raises:
            NotFoundError if the room is unknown
        """
        state_ids = await self.get_current_state_ids(room_id)

        if not state_ids:
            raise NotFoundError(f"Current state for room {room_id} is empty")

        create_id = state_ids.get((EventTypes.Create, ""))

        # If we can't find the create event, assume we've hit a dead end
        if not create_id:
            raise NotFoundError(f"No create event in current state for room {room_id}")

        # Retrieve the room's create event and return
        create_event = await self.get_event(create_id)
        return create_event

    @cached(max_entries=100000, iterable=True)
    async def get_current_state_ids(self, room_id: str) -> StateMap[str]:
        """Get the current state event ids for a room based on the
        current_state_events table.

        Args:
            room_id: The room to get the state IDs of.

        Returns:
            The current state of the room.
        """

        def _get_current_state_ids_txn(txn: LoggingTransaction) -> StateMap[str]:
            txn.execute(
                """SELECT type, state_key, event_id FROM current_state_events
                WHERE room_id = ?
                """,
                (room_id,),
            )

            return {(intern_string(r[0]), intern_string(r[1])): r[2] for r in txn}

        return await self.db_pool.runInteraction(
            "get_current_state_ids", _get_current_state_ids_txn
        )

    # FIXME: how should this be cached?
    async def get_filtered_current_state_ids(
        self, room_id: str, state_filter: Optional[StateFilter] = None
    ) -> StateMap[str]:
        """Get the current state event of a given type for a room based on the
        current_state_events table.  This may not be as up-to-date as the result
        of doing a fresh state resolution as per state_handler.get_current_state

        Args:
            room_id
            state_filter: The state filter used to fetch state
                from the database.

        Returns:
            Map from type/state_key to event ID.
        """

        where_clause, where_args = (
            state_filter or StateFilter.all()
        ).make_sql_filter_clause()

        if not where_clause:
            # We delegate to the cached version
            return await self.get_current_state_ids(room_id)

        def _get_filtered_current_state_ids_txn(
            txn: LoggingTransaction,
        ) -> StateMap[str]:
            results = {}
            sql = """
                SELECT type, state_key, event_id FROM current_state_events
                WHERE room_id = ?
            """

            if where_clause:
                sql += " AND (%s)" % (where_clause,)

            args = [room_id]
            args.extend(where_args)
            txn.execute(sql, args)
            for row in txn:
                typ, state_key, event_id = row
                key = (intern_string(typ), intern_string(state_key))
                results[key] = event_id

            return results

        return await self.db_pool.runInteraction(
            "get_filtered_current_state_ids", _get_filtered_current_state_ids_txn
        )

    async def get_canonical_alias_for_room(self, room_id: str) -> Optional[str]:
        """Get canonical alias for room, if any

        Args:
            room_id: The room ID

        Returns:
            The canonical alias, if any
        """

        state = await self.get_filtered_current_state_ids(
            room_id, StateFilter.from_types([(EventTypes.CanonicalAlias, "")])
        )

        event_id = state.get((EventTypes.CanonicalAlias, ""))
        if not event_id:
            return None

        event = await self.get_event(event_id, allow_none=True)
        if not event:
            return None

        return event.content.get("canonical_alias")

    @cached(max_entries=50000)
    async def _get_state_group_for_event(self, event_id: str) -> Optional[int]:
        return await self.db_pool.simple_select_one_onecol(
            table="event_to_state_groups",
            keyvalues={"event_id": event_id},
            retcol="state_group",
            allow_none=True,
            desc="_get_state_group_for_event",
        )

    @cachedList(
        cached_method_name="_get_state_group_for_event",
        list_name="event_ids",
        num_args=1,
    )
    async def _get_state_group_for_events(
        self, event_ids: Collection[str]
    ) -> Dict[str, int]:
        """Returns mapping event_id -> state_group.

        Raises:
             RuntimeError if the state is unknown at any of the given events
        """
        rows = await self.db_pool.simple_select_many_batch(
            table="event_to_state_groups",
            column="event_id",
            iterable=event_ids,
            keyvalues={},
            retcols=("event_id", "state_group"),
            desc="_get_state_group_for_events",
        )

        res = {row["event_id"]: row["state_group"] for row in rows}
        for e in event_ids:
            if e not in res:
                raise RuntimeError("No state group for unknown or outlier event %s" % e)
        return res

    async def get_referenced_state_groups(
        self, state_groups: Iterable[int]
    ) -> Set[int]:
        """Check if the state groups are referenced by events.

        Args:
            state_groups

        Returns:
            The subset of state groups that are referenced.
        """

        rows = await self.db_pool.simple_select_many_batch(
            table="event_to_state_groups",
            column="state_group",
            iterable=state_groups,
            keyvalues={},
            retcols=("DISTINCT state_group",),
            desc="get_referenced_state_groups",
        )

        return {row["state_group"] for row in rows}

    async def update_state_for_partial_state_event(
        self,
        event: EventBase,
        context: EventContext,
    ) -> None:
        """Update the state group for a partial state event"""
        await self.db_pool.runInteraction(
            "update_state_for_partial_state_event",
            self._update_state_for_partial_state_event_txn,
            event,
            context,
        )

    def _update_state_for_partial_state_event_txn(
        self,
        txn,
        event: EventBase,
        context: EventContext,
    ):
        # we shouldn't have any outliers here
        assert not event.internal_metadata.is_outlier()

        # anything that was rejected should have the same state as its
        # predecessor.
        if context.rejected:
            assert context.state_group == context.state_group_before_event

        self.db_pool.simple_update_txn(
            txn,
            table="event_to_state_groups",
            keyvalues={"event_id": event.event_id},
            updatevalues={"state_group": context.state_group},
        )

        self.db_pool.simple_delete_one_txn(
            txn,
            table="partial_state_events",
            keyvalues={"event_id": event.event_id},
        )

        # TODO(faster_joins): need to do something about workers here
        txn.call_after(
            self._get_state_group_for_event.prefill,
            (event.event_id,),
            context.state_group,
        )


class MainStateBackgroundUpdateStore(RoomMemberWorkerStore):

    CURRENT_STATE_INDEX_UPDATE_NAME = "current_state_members_idx"
    EVENT_STATE_GROUP_INDEX_UPDATE_NAME = "event_to_state_groups_sg_index"
    DELETE_CURRENT_STATE_UPDATE_NAME = "delete_old_current_state_events"

    def __init__(
        self,
        database: DatabasePool,
        db_conn: LoggingDatabaseConnection,
        hs: "HomeServer",
    ):
        super().__init__(database, db_conn, hs)

        self.server_name: str = hs.hostname

        self.db_pool.updates.register_background_index_update(
            self.CURRENT_STATE_INDEX_UPDATE_NAME,
            index_name="current_state_events_member_index",
            table="current_state_events",
            columns=["state_key"],
            where_clause="type='m.room.member'",
        )
        self.db_pool.updates.register_background_index_update(
            self.EVENT_STATE_GROUP_INDEX_UPDATE_NAME,
            index_name="event_to_state_groups_sg_index",
            table="event_to_state_groups",
            columns=["state_group"],
        )
        self.db_pool.updates.register_background_update_handler(
            self.DELETE_CURRENT_STATE_UPDATE_NAME,
            self._background_remove_left_rooms,
        )

    async def _background_remove_left_rooms(
        self, progress: JsonDict, batch_size: int
    ) -> int:
        """Background update to delete rows from `current_state_events` and
        `event_forward_extremities` tables of rooms that the server is no
        longer joined to.
        """

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

        def _background_remove_left_rooms_txn(
            txn: LoggingTransaction,
        ) -> Tuple[bool, Set[str]]:
            # get a batch of room ids to consider
            sql = """
                SELECT DISTINCT room_id FROM current_state_events
                WHERE room_id > ? ORDER BY room_id LIMIT ?
            """

            txn.execute(sql, (last_room_id, batch_size))
            room_ids = [row[0] for row in txn]
            if not room_ids:
                return True, set()

            ###########################################################################
            #
            # exclude rooms where we have active members

            sql = """
                SELECT room_id
                FROM local_current_membership
                WHERE
                    room_id > ? AND room_id <= ?
                    AND membership = 'join'
                GROUP BY room_id
            """

            txn.execute(sql, (last_room_id, room_ids[-1]))
            joined_room_ids = {row[0] for row in txn}
            to_delete = set(room_ids) - joined_room_ids

            ###########################################################################
            #
            # exclude rooms which we are in the process of constructing; these otherwise
            # qualify as "rooms with no local users", and would have their
            # forward extremities cleaned up.

            # the following query will return a list of rooms which have forward
            # extremities that are *not* also the create event in the room - ie
            # those that are not being created currently.

            sql = """
                SELECT DISTINCT efe.room_id
                FROM event_forward_extremities efe
                LEFT JOIN current_state_events cse ON
                    cse.event_id = efe.event_id
                    AND cse.type = 'm.room.create'
                    AND cse.state_key = ''
                WHERE
                    cse.event_id IS NULL
                    AND efe.room_id > ? AND efe.room_id <= ?
            """

            txn.execute(sql, (last_room_id, room_ids[-1]))

            # build a set of those rooms within `to_delete` that do not appear in
            # the above, leaving us with the rooms in `to_delete` that *are* being
            # created.
            creating_rooms = to_delete.difference(row[0] for row in txn)
            logger.info("skipping rooms which are being created: %s", creating_rooms)

            # now remove the rooms being created from the list of those to delete.
            #
            # (we could have just taken the intersection of `to_delete` with the result
            # of the sql query, but it's useful to be able to log `creating_rooms`; and
            # having done so, it's quicker to remove the (few) creating rooms from
            # `to_delete` than it is to form the intersection with the (larger) list of
            # not-creating-rooms)

            to_delete -= creating_rooms

            ###########################################################################
            #
            # now clear the state for the rooms

            logger.info("Deleting current state left rooms: %r", to_delete)

            # First we get all users that we still think were joined to the
            # room. This is so that we can mark those device lists as
            # potentially stale, since there may have been a period where the
            # server didn't share a room with the remote user and therefore may
            # have missed any device updates.
            rows = self.db_pool.simple_select_many_txn(
                txn,
                table="current_state_events",
                column="room_id",
                iterable=to_delete,
                keyvalues={"type": EventTypes.Member, "membership": Membership.JOIN},
                retcols=("state_key",),
            )

            potentially_left_users = {row["state_key"] for row in rows}

            # Now lets actually delete the rooms from the DB.
            self.db_pool.simple_delete_many_txn(
                txn,
                table="current_state_events",
                column="room_id",
                values=to_delete,
                keyvalues={},
            )

            self.db_pool.simple_delete_many_txn(
                txn,
                table="event_forward_extremities",
                column="room_id",
                values=to_delete,
                keyvalues={},
            )

            self.db_pool.updates._background_update_progress_txn(
                txn,
                self.DELETE_CURRENT_STATE_UPDATE_NAME,
                {"last_room_id": room_ids[-1]},
            )

            return False, potentially_left_users

        finished, potentially_left_users = await self.db_pool.runInteraction(
            "_background_remove_left_rooms", _background_remove_left_rooms_txn
        )

        if finished:
            await self.db_pool.updates._end_background_update(
                self.DELETE_CURRENT_STATE_UPDATE_NAME
            )

        # Now go and check if we still share a room with the remote users in
        # the deleted rooms. If not mark their device lists as stale.
        joined_users = await self.get_users_server_still_shares_room_with(
            potentially_left_users
        )

        for user_id in potentially_left_users - joined_users:
            await self.mark_remote_user_device_list_as_unsubscribed(user_id)  # type: ignore[attr-defined]

        return batch_size


class StateStore(StateGroupWorkerStore, MainStateBackgroundUpdateStore):
    """Keeps track of the state at a given event.

    This is done by the concept of `state groups`. Every event is a assigned
    a state group (identified by an arbitrary string), which references a
    collection of state events. The current state of an event is then the
    collection of state events referenced by the event's state group.

    Hence, every change in the current state causes a new state group to be
    generated. However, if no change happens (e.g., if we get a message event
    with only one parent it inherits the state group from its parent.)

    There are three tables:
      * `state_groups`: Stores group name, first event with in the group and
        room id.
      * `event_to_state_groups`: Maps events to state groups.
      * `state_groups_state`: Maps state group to state events.
    """

    def __init__(
        self,
        database: DatabasePool,
        db_conn: LoggingDatabaseConnection,
        hs: "HomeServer",
    ):
        super().__init__(database, db_conn, hs)