synapse-old/synapse/storage/databases/main/events_bg_updates.py

931 lines
34 KiB
Python

# -*- coding: utf-8 -*-
# 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 logging
from typing import Dict, List, Optional, Tuple
import attr
from synapse.api.constants import EventContentFields
from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
from synapse.events import make_event_from_dict
from synapse.storage._base import SQLBaseStore, db_to_json, make_in_list_sql_clause
from synapse.storage.database import DatabasePool, make_tuple_comparison_clause
from synapse.storage.databases.main.events import PersistEventsStore
from synapse.storage.types import Cursor
from synapse.types import JsonDict
logger = logging.getLogger(__name__)
@attr.s(slots=True, frozen=True)
class _CalculateChainCover:
"""Return value for _calculate_chain_cover_txn.
"""
# The last room_id/depth/stream processed.
room_id = attr.ib(type=str)
depth = attr.ib(type=int)
stream = attr.ib(type=int)
# Number of rows processed
processed_count = attr.ib(type=int)
# Map from room_id to last depth/stream processed for each room that we have
# processed all events for (i.e. the rooms we can flip the
# `has_auth_chain_index` for)
finished_room_map = attr.ib(type=Dict[str, Tuple[int, int]])
class EventsBackgroundUpdatesStore(SQLBaseStore):
EVENT_ORIGIN_SERVER_TS_NAME = "event_origin_server_ts"
EVENT_FIELDS_SENDER_URL_UPDATE_NAME = "event_fields_sender_url"
DELETE_SOFT_FAILED_EXTREMITIES = "delete_soft_failed_extremities"
def __init__(self, database: DatabasePool, db_conn, hs):
super().__init__(database, db_conn, hs)
self.db_pool.updates.register_background_update_handler(
self.EVENT_ORIGIN_SERVER_TS_NAME, self._background_reindex_origin_server_ts
)
self.db_pool.updates.register_background_update_handler(
self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME,
self._background_reindex_fields_sender,
)
self.db_pool.updates.register_background_index_update(
"event_contains_url_index",
index_name="event_contains_url_index",
table="events",
columns=["room_id", "topological_ordering", "stream_ordering"],
where_clause="contains_url = true AND outlier = false",
)
# an event_id index on event_search is useful for the purge_history
# api. Plus it means we get to enforce some integrity with a UNIQUE
# clause
self.db_pool.updates.register_background_index_update(
"event_search_event_id_idx",
index_name="event_search_event_id_idx",
table="event_search",
columns=["event_id"],
unique=True,
psql_only=True,
)
self.db_pool.updates.register_background_update_handler(
self.DELETE_SOFT_FAILED_EXTREMITIES, self._cleanup_extremities_bg_update
)
self.db_pool.updates.register_background_update_handler(
"redactions_received_ts", self._redactions_received_ts
)
# This index gets deleted in `event_fix_redactions_bytes` update
self.db_pool.updates.register_background_index_update(
"event_fix_redactions_bytes_create_index",
index_name="redactions_censored_redacts",
table="redactions",
columns=["redacts"],
where_clause="have_censored",
)
self.db_pool.updates.register_background_update_handler(
"event_fix_redactions_bytes", self._event_fix_redactions_bytes
)
self.db_pool.updates.register_background_update_handler(
"event_store_labels", self._event_store_labels
)
self.db_pool.updates.register_background_index_update(
"redactions_have_censored_ts_idx",
index_name="redactions_have_censored_ts",
table="redactions",
columns=["received_ts"],
where_clause="NOT have_censored",
)
self.db_pool.updates.register_background_index_update(
"users_have_local_media",
index_name="users_have_local_media",
table="local_media_repository",
columns=["user_id", "created_ts"],
)
self.db_pool.updates.register_background_update_handler(
"rejected_events_metadata", self._rejected_events_metadata,
)
self.db_pool.updates.register_background_update_handler(
"chain_cover", self._chain_cover_index,
)
async def _background_reindex_fields_sender(self, progress, batch_size):
target_min_stream_id = progress["target_min_stream_id_inclusive"]
max_stream_id = progress["max_stream_id_exclusive"]
rows_inserted = progress.get("rows_inserted", 0)
INSERT_CLUMP_SIZE = 1000
def reindex_txn(txn):
sql = (
"SELECT stream_ordering, event_id, json FROM events"
" INNER JOIN event_json USING (event_id)"
" WHERE ? <= stream_ordering AND stream_ordering < ?"
" ORDER BY stream_ordering DESC"
" LIMIT ?"
)
txn.execute(sql, (target_min_stream_id, max_stream_id, batch_size))
rows = txn.fetchall()
if not rows:
return 0
min_stream_id = rows[-1][0]
update_rows = []
for row in rows:
try:
event_id = row[1]
event_json = db_to_json(row[2])
sender = event_json["sender"]
content = event_json["content"]
contains_url = "url" in content
if contains_url:
contains_url &= isinstance(content["url"], str)
except (KeyError, AttributeError):
# If the event is missing a necessary field then
# skip over it.
continue
update_rows.append((sender, contains_url, event_id))
sql = "UPDATE events SET sender = ?, contains_url = ? WHERE event_id = ?"
for index in range(0, len(update_rows), INSERT_CLUMP_SIZE):
clump = update_rows[index : index + INSERT_CLUMP_SIZE]
txn.executemany(sql, clump)
progress = {
"target_min_stream_id_inclusive": target_min_stream_id,
"max_stream_id_exclusive": min_stream_id,
"rows_inserted": rows_inserted + len(rows),
}
self.db_pool.updates._background_update_progress_txn(
txn, self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME, progress
)
return len(rows)
result = await self.db_pool.runInteraction(
self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME, reindex_txn
)
if not result:
await self.db_pool.updates._end_background_update(
self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME
)
return result
async def _background_reindex_origin_server_ts(self, progress, batch_size):
target_min_stream_id = progress["target_min_stream_id_inclusive"]
max_stream_id = progress["max_stream_id_exclusive"]
rows_inserted = progress.get("rows_inserted", 0)
INSERT_CLUMP_SIZE = 1000
def reindex_search_txn(txn):
sql = (
"SELECT stream_ordering, event_id FROM events"
" WHERE ? <= stream_ordering AND stream_ordering < ?"
" ORDER BY stream_ordering DESC"
" LIMIT ?"
)
txn.execute(sql, (target_min_stream_id, max_stream_id, batch_size))
rows = txn.fetchall()
if not rows:
return 0
min_stream_id = rows[-1][0]
event_ids = [row[1] for row in rows]
rows_to_update = []
chunks = [event_ids[i : i + 100] for i in range(0, len(event_ids), 100)]
for chunk in chunks:
ev_rows = self.db_pool.simple_select_many_txn(
txn,
table="event_json",
column="event_id",
iterable=chunk,
retcols=["event_id", "json"],
keyvalues={},
)
for row in ev_rows:
event_id = row["event_id"]
event_json = db_to_json(row["json"])
try:
origin_server_ts = event_json["origin_server_ts"]
except (KeyError, AttributeError):
# If the event is missing a necessary field then
# skip over it.
continue
rows_to_update.append((origin_server_ts, event_id))
sql = "UPDATE events SET origin_server_ts = ? WHERE event_id = ?"
for index in range(0, len(rows_to_update), INSERT_CLUMP_SIZE):
clump = rows_to_update[index : index + INSERT_CLUMP_SIZE]
txn.executemany(sql, clump)
progress = {
"target_min_stream_id_inclusive": target_min_stream_id,
"max_stream_id_exclusive": min_stream_id,
"rows_inserted": rows_inserted + len(rows_to_update),
}
self.db_pool.updates._background_update_progress_txn(
txn, self.EVENT_ORIGIN_SERVER_TS_NAME, progress
)
return len(rows_to_update)
result = await self.db_pool.runInteraction(
self.EVENT_ORIGIN_SERVER_TS_NAME, reindex_search_txn
)
if not result:
await self.db_pool.updates._end_background_update(
self.EVENT_ORIGIN_SERVER_TS_NAME
)
return result
async def _cleanup_extremities_bg_update(self, progress, batch_size):
"""Background update to clean out extremities that should have been
deleted previously.
Mainly used to deal with the aftermath of #5269.
"""
# This works by first copying all existing forward extremities into the
# `_extremities_to_check` table at start up, and then checking each
# event in that table whether we have any descendants that are not
# soft-failed/rejected. If that is the case then we delete that event
# from the forward extremities table.
#
# For efficiency, we do this in batches by recursively pulling out all
# descendants of a batch until we find the non soft-failed/rejected
# events, i.e. the set of descendants whose chain of prev events back
# to the batch of extremities are all soft-failed or rejected.
# Typically, we won't find any such events as extremities will rarely
# have any descendants, but if they do then we should delete those
# extremities.
def _cleanup_extremities_bg_update_txn(txn):
# The set of extremity event IDs that we're checking this round
original_set = set()
# A dict[str, set[str]] of event ID to their prev events.
graph = {}
# The set of descendants of the original set that are not rejected
# nor soft-failed. Ancestors of these events should be removed
# from the forward extremities table.
non_rejected_leaves = set()
# Set of event IDs that have been soft failed, and for which we
# should check if they have descendants which haven't been soft
# failed.
soft_failed_events_to_lookup = set()
# First, we get `batch_size` events from the table, pulling out
# their successor events, if any, and the successor events'
# rejection status.
txn.execute(
"""SELECT prev_event_id, event_id, internal_metadata,
rejections.event_id IS NOT NULL, events.outlier
FROM (
SELECT event_id AS prev_event_id
FROM _extremities_to_check
LIMIT ?
) AS f
LEFT JOIN event_edges USING (prev_event_id)
LEFT JOIN events USING (event_id)
LEFT JOIN event_json USING (event_id)
LEFT JOIN rejections USING (event_id)
""",
(batch_size,),
)
for prev_event_id, event_id, metadata, rejected, outlier in txn:
original_set.add(prev_event_id)
if not event_id or outlier:
# Common case where the forward extremity doesn't have any
# descendants.
continue
graph.setdefault(event_id, set()).add(prev_event_id)
soft_failed = False
if metadata:
soft_failed = db_to_json(metadata).get("soft_failed")
if soft_failed or rejected:
soft_failed_events_to_lookup.add(event_id)
else:
non_rejected_leaves.add(event_id)
# Now we recursively check all the soft-failed descendants we
# found above in the same way, until we have nothing left to
# check.
while soft_failed_events_to_lookup:
# We only want to do 100 at a time, so we split given list
# into two.
batch = list(soft_failed_events_to_lookup)
to_check, to_defer = batch[:100], batch[100:]
soft_failed_events_to_lookup = set(to_defer)
sql = """SELECT prev_event_id, event_id, internal_metadata,
rejections.event_id IS NOT NULL
FROM event_edges
INNER JOIN events USING (event_id)
INNER JOIN event_json USING (event_id)
LEFT JOIN rejections USING (event_id)
WHERE
NOT events.outlier
AND
"""
clause, args = make_in_list_sql_clause(
self.database_engine, "prev_event_id", to_check
)
txn.execute(sql + clause, list(args))
for prev_event_id, event_id, metadata, rejected in txn:
if event_id in graph:
# Already handled this event previously, but we still
# want to record the edge.
graph[event_id].add(prev_event_id)
continue
graph[event_id] = {prev_event_id}
soft_failed = db_to_json(metadata).get("soft_failed")
if soft_failed or rejected:
soft_failed_events_to_lookup.add(event_id)
else:
non_rejected_leaves.add(event_id)
# We have a set of non-soft-failed descendants, so we recurse up
# the graph to find all ancestors and add them to the set of event
# IDs that we can delete from forward extremities table.
to_delete = set()
while non_rejected_leaves:
event_id = non_rejected_leaves.pop()
prev_event_ids = graph.get(event_id, set())
non_rejected_leaves.update(prev_event_ids)
to_delete.update(prev_event_ids)
to_delete.intersection_update(original_set)
deleted = self.db_pool.simple_delete_many_txn(
txn=txn,
table="event_forward_extremities",
column="event_id",
iterable=to_delete,
keyvalues={},
)
logger.info(
"Deleted %d forward extremities of %d checked, to clean up #5269",
deleted,
len(original_set),
)
if deleted:
# We now need to invalidate the caches of these rooms
rows = self.db_pool.simple_select_many_txn(
txn,
table="events",
column="event_id",
iterable=to_delete,
keyvalues={},
retcols=("room_id",),
)
room_ids = {row["room_id"] for row in rows}
for room_id in room_ids:
txn.call_after(
self.get_latest_event_ids_in_room.invalidate, (room_id,)
)
self.db_pool.simple_delete_many_txn(
txn=txn,
table="_extremities_to_check",
column="event_id",
iterable=original_set,
keyvalues={},
)
return len(original_set)
num_handled = await self.db_pool.runInteraction(
"_cleanup_extremities_bg_update", _cleanup_extremities_bg_update_txn
)
if not num_handled:
await self.db_pool.updates._end_background_update(
self.DELETE_SOFT_FAILED_EXTREMITIES
)
def _drop_table_txn(txn):
txn.execute("DROP TABLE _extremities_to_check")
await self.db_pool.runInteraction(
"_cleanup_extremities_bg_update_drop_table", _drop_table_txn
)
return num_handled
async def _redactions_received_ts(self, progress, batch_size):
"""Handles filling out the `received_ts` column in redactions.
"""
last_event_id = progress.get("last_event_id", "")
def _redactions_received_ts_txn(txn):
# Fetch the set of event IDs that we want to update
sql = """
SELECT event_id FROM redactions
WHERE event_id > ?
ORDER BY event_id ASC
LIMIT ?
"""
txn.execute(sql, (last_event_id, batch_size))
rows = txn.fetchall()
if not rows:
return 0
(upper_event_id,) = rows[-1]
# Update the redactions with the received_ts.
#
# Note: Not all events have an associated received_ts, so we
# fallback to using origin_server_ts. If we for some reason don't
# have an origin_server_ts, lets just use the current timestamp.
#
# We don't want to leave it null, as then we'll never try and
# censor those redactions.
sql = """
UPDATE redactions
SET received_ts = (
SELECT COALESCE(received_ts, origin_server_ts, ?) FROM events
WHERE events.event_id = redactions.event_id
)
WHERE ? <= event_id AND event_id <= ?
"""
txn.execute(sql, (self._clock.time_msec(), last_event_id, upper_event_id))
self.db_pool.updates._background_update_progress_txn(
txn, "redactions_received_ts", {"last_event_id": upper_event_id}
)
return len(rows)
count = await self.db_pool.runInteraction(
"_redactions_received_ts", _redactions_received_ts_txn
)
if not count:
await self.db_pool.updates._end_background_update("redactions_received_ts")
return count
async def _event_fix_redactions_bytes(self, progress, batch_size):
"""Undoes hex encoded censored redacted event JSON.
"""
def _event_fix_redactions_bytes_txn(txn):
# This update is quite fast due to new index.
txn.execute(
"""
UPDATE event_json
SET
json = convert_from(json::bytea, 'utf8')
FROM redactions
WHERE
redactions.have_censored
AND event_json.event_id = redactions.redacts
AND json NOT LIKE '{%';
"""
)
txn.execute("DROP INDEX redactions_censored_redacts")
await self.db_pool.runInteraction(
"_event_fix_redactions_bytes", _event_fix_redactions_bytes_txn
)
await self.db_pool.updates._end_background_update("event_fix_redactions_bytes")
return 1
async def _event_store_labels(self, progress, batch_size):
"""Background update handler which will store labels for existing events."""
last_event_id = progress.get("last_event_id", "")
def _event_store_labels_txn(txn):
txn.execute(
"""
SELECT event_id, json FROM event_json
LEFT JOIN event_labels USING (event_id)
WHERE event_id > ? AND label IS NULL
ORDER BY event_id LIMIT ?
""",
(last_event_id, batch_size),
)
results = list(txn)
nbrows = 0
last_row_event_id = ""
for (event_id, event_json_raw) in results:
try:
event_json = db_to_json(event_json_raw)
self.db_pool.simple_insert_many_txn(
txn=txn,
table="event_labels",
values=[
{
"event_id": event_id,
"label": label,
"room_id": event_json["room_id"],
"topological_ordering": event_json["depth"],
}
for label in event_json["content"].get(
EventContentFields.LABELS, []
)
if isinstance(label, str)
],
)
except Exception as e:
logger.warning(
"Unable to load event %s (no labels will be imported): %s",
event_id,
e,
)
nbrows += 1
last_row_event_id = event_id
self.db_pool.updates._background_update_progress_txn(
txn, "event_store_labels", {"last_event_id": last_row_event_id}
)
return nbrows
num_rows = await self.db_pool.runInteraction(
desc="event_store_labels", func=_event_store_labels_txn
)
if not num_rows:
await self.db_pool.updates._end_background_update("event_store_labels")
return num_rows
async def _rejected_events_metadata(self, progress: dict, batch_size: int) -> int:
"""Adds rejected events to the `state_events` and `event_auth` metadata
tables.
"""
last_event_id = progress.get("last_event_id", "")
def get_rejected_events(
txn: Cursor,
) -> List[Tuple[str, str, JsonDict, bool, bool]]:
# Fetch rejected event json, their room version and whether we have
# inserted them into the state_events or auth_events tables.
#
# Note we can assume that events that don't have a corresponding
# room version are V1 rooms.
sql = """
SELECT DISTINCT
event_id,
COALESCE(room_version, '1'),
json,
state_events.event_id IS NOT NULL,
event_auth.event_id IS NOT NULL
FROM rejections
INNER JOIN event_json USING (event_id)
LEFT JOIN rooms USING (room_id)
LEFT JOIN state_events USING (event_id)
LEFT JOIN event_auth USING (event_id)
WHERE event_id > ?
ORDER BY event_id
LIMIT ?
"""
txn.execute(sql, (last_event_id, batch_size,))
return [(row[0], row[1], db_to_json(row[2]), row[3], row[4]) for row in txn] # type: ignore
results = await self.db_pool.runInteraction(
desc="_rejected_events_metadata_get", func=get_rejected_events
)
if not results:
await self.db_pool.updates._end_background_update(
"rejected_events_metadata"
)
return 0
state_events = []
auth_events = []
for event_id, room_version, event_json, has_state, has_event_auth in results:
last_event_id = event_id
if has_state and has_event_auth:
continue
room_version_obj = KNOWN_ROOM_VERSIONS.get(room_version)
if not room_version_obj:
# We no longer support this room version, so we just ignore the
# events entirely.
logger.info(
"Ignoring event with unknown room version %r: %r",
room_version,
event_id,
)
continue
event = make_event_from_dict(event_json, room_version_obj)
if not event.is_state():
continue
if not has_state:
state_events.append(
{
"event_id": event.event_id,
"room_id": event.room_id,
"type": event.type,
"state_key": event.state_key,
}
)
if not has_event_auth:
for auth_id in event.auth_event_ids():
auth_events.append(
{
"room_id": event.room_id,
"event_id": event.event_id,
"auth_id": auth_id,
}
)
if state_events:
await self.db_pool.simple_insert_many(
table="state_events",
values=state_events,
desc="_rejected_events_metadata_state_events",
)
if auth_events:
await self.db_pool.simple_insert_many(
table="event_auth",
values=auth_events,
desc="_rejected_events_metadata_event_auth",
)
await self.db_pool.updates._background_update_progress(
"rejected_events_metadata", {"last_event_id": last_event_id}
)
if len(results) < batch_size:
await self.db_pool.updates._end_background_update(
"rejected_events_metadata"
)
return len(results)
async def _chain_cover_index(self, progress: dict, batch_size: int) -> int:
"""A background updates that iterates over all rooms and generates the
chain cover index for them.
"""
current_room_id = progress.get("current_room_id", "")
# Where we've processed up to in the room, defaults to the start of the
# room.
last_depth = progress.get("last_depth", -1)
last_stream = progress.get("last_stream", -1)
result = await self.db_pool.runInteraction(
"_chain_cover_index",
self._calculate_chain_cover_txn,
current_room_id,
last_depth,
last_stream,
batch_size,
single_room=False,
)
finished = result.processed_count == 0
total_rows_processed = result.processed_count
current_room_id = result.room_id
last_depth = result.depth
last_stream = result.stream
for room_id, (depth, stream) in result.finished_room_map.items():
# If we've done all the events in the room we flip the
# `has_auth_chain_index` in the DB. Note that its possible for
# further events to be persisted between the above and setting the
# flag without having the chain cover calculated for them. This is
# fine as a) the code gracefully handles these cases and b) we'll
# calculate them below.
await self.db_pool.simple_update(
table="rooms",
keyvalues={"room_id": room_id},
updatevalues={"has_auth_chain_index": True},
desc="_chain_cover_index",
)
# Handle any events that might have raced with us flipping the
# bit above.
result = await self.db_pool.runInteraction(
"_chain_cover_index",
self._calculate_chain_cover_txn,
room_id,
depth,
stream,
batch_size=None,
single_room=True,
)
total_rows_processed += result.processed_count
if finished:
await self.db_pool.updates._end_background_update("chain_cover")
return total_rows_processed
await self.db_pool.updates._background_update_progress(
"chain_cover",
{
"current_room_id": current_room_id,
"last_depth": last_depth,
"last_stream": last_stream,
},
)
return total_rows_processed
def _calculate_chain_cover_txn(
self,
txn: Cursor,
last_room_id: str,
last_depth: int,
last_stream: int,
batch_size: Optional[int],
single_room: bool,
) -> _CalculateChainCover:
"""Calculate the chain cover for `batch_size` events, ordered by
`(room_id, depth, stream)`.
Args:
txn,
last_room_id, last_depth, last_stream: The `(room_id, depth, stream)`
tuple to fetch results after.
batch_size: The maximum number of events to process. If None then
no limit.
single_room: Whether to calculate the index for just the given
room.
"""
# Get the next set of events in the room (that we haven't already
# computed chain cover for). We do this in topological order.
# We want to do a `(topological_ordering, stream_ordering) > (?,?)`
# comparison, but that is not supported on older SQLite versions
tuple_clause, tuple_args = make_tuple_comparison_clause(
self.database_engine,
[
("events.room_id", last_room_id),
("topological_ordering", last_depth),
("stream_ordering", last_stream),
],
)
extra_clause = ""
if single_room:
extra_clause = "AND events.room_id = ?"
tuple_args.append(last_room_id)
sql = """
SELECT
event_id, state_events.type, state_events.state_key,
topological_ordering, stream_ordering,
events.room_id
FROM events
INNER JOIN state_events USING (event_id)
LEFT JOIN event_auth_chains USING (event_id)
LEFT JOIN event_auth_chain_to_calculate USING (event_id)
WHERE event_auth_chains.event_id IS NULL
AND event_auth_chain_to_calculate.event_id IS NULL
AND %(tuple_cmp)s
%(extra)s
ORDER BY events.room_id, topological_ordering, stream_ordering
%(limit)s
""" % {
"tuple_cmp": tuple_clause,
"limit": "LIMIT ?" if batch_size is not None else "",
"extra": extra_clause,
}
if batch_size is not None:
tuple_args.append(batch_size)
txn.execute(sql, tuple_args)
rows = txn.fetchall()
# Put the results in the necessary format for
# `_add_chain_cover_index`
event_to_room_id = {row[0]: row[5] for row in rows}
event_to_types = {row[0]: (row[1], row[2]) for row in rows}
# Calculate the new last position we've processed up to.
new_last_depth = rows[-1][3] if rows else last_depth # type: int
new_last_stream = rows[-1][4] if rows else last_stream # type: int
new_last_room_id = rows[-1][5] if rows else "" # type: str
# Map from room_id to last depth/stream_ordering processed for the room,
# excluding the last room (which we're likely still processing). We also
# need to include the room passed in if it's not included in the result
# set (as we then know we've processed all events in said room).
#
# This is the set of rooms that we can now safely flip the
# `has_auth_chain_index` bit for.
finished_rooms = {
row[5]: (row[3], row[4]) for row in rows if row[5] != new_last_room_id
}
if last_room_id not in finished_rooms and last_room_id != new_last_room_id:
finished_rooms[last_room_id] = (last_depth, last_stream)
count = len(rows)
# We also need to fetch the auth events for them.
auth_events = self.db_pool.simple_select_many_txn(
txn,
table="event_auth",
column="event_id",
iterable=event_to_room_id,
keyvalues={},
retcols=("event_id", "auth_id"),
)
event_to_auth_chain = {} # type: Dict[str, List[str]]
for row in auth_events:
event_to_auth_chain.setdefault(row["event_id"], []).append(row["auth_id"])
# Calculate and persist the chain cover index for this set of events.
#
# Annoyingly we need to gut wrench into the persit event store so that
# we can reuse the function to calculate the chain cover for rooms.
PersistEventsStore._add_chain_cover_index(
txn, self.db_pool, event_to_room_id, event_to_types, event_to_auth_chain,
)
return _CalculateChainCover(
room_id=new_last_room_id,
depth=new_last_depth,
stream=new_last_stream,
processed_count=count,
finished_room_map=finished_rooms,
)