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864 lines
36 KiB
Python
864 lines
36 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright 2014-2016 OpenMarket Ltd
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# Copyright 2018-2019 New Vector Ltd
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# Copyright 2019 The Matrix.org Foundation C.I.C.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import itertools
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import logging
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from collections import deque, namedtuple
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from typing import Dict, Iterable, List, Optional, Set, Tuple
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from prometheus_client import Counter, Histogram
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from twisted.internet import defer
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from synapse.api.constants import EventTypes, Membership
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from synapse.events import EventBase
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from synapse.events.snapshot import EventContext
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from synapse.logging.context import PreserveLoggingContext, make_deferred_yieldable
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from synapse.metrics.background_process_metrics import run_as_background_process
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from synapse.storage.databases import Databases
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from synapse.storage.databases.main.events import DeltaState
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from synapse.types import Collection, PersistedEventPosition, RoomStreamToken, StateMap
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from synapse.util.async_helpers import ObservableDeferred
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from synapse.util.metrics import Measure
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logger = logging.getLogger(__name__)
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# The number of times we are recalculating the current state
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state_delta_counter = Counter("synapse_storage_events_state_delta", "")
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# The number of times we are recalculating state when there is only a
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# single forward extremity
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state_delta_single_event_counter = Counter(
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"synapse_storage_events_state_delta_single_event", ""
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)
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# The number of times we are reculating state when we could have resonably
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# calculated the delta when we calculated the state for an event we were
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# persisting.
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state_delta_reuse_delta_counter = Counter(
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"synapse_storage_events_state_delta_reuse_delta", ""
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)
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# The number of forward extremities for each new event.
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forward_extremities_counter = Histogram(
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"synapse_storage_events_forward_extremities_persisted",
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"Number of forward extremities for each new event",
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buckets=(1, 2, 3, 5, 7, 10, 15, 20, 50, 100, 200, 500, "+Inf"),
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)
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# The number of stale forward extremities for each new event. Stale extremities
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# are those that were in the previous set of extremities as well as the new.
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stale_forward_extremities_counter = Histogram(
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"synapse_storage_events_stale_forward_extremities_persisted",
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"Number of unchanged forward extremities for each new event",
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buckets=(0, 1, 2, 3, 5, 7, 10, 15, 20, 50, 100, 200, 500, "+Inf"),
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)
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class _EventPeristenceQueue:
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"""Queues up events so that they can be persisted in bulk with only one
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concurrent transaction per room.
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"""
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_EventPersistQueueItem = namedtuple(
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"_EventPersistQueueItem", ("events_and_contexts", "backfilled", "deferred")
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)
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def __init__(self):
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self._event_persist_queues = {}
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self._currently_persisting_rooms = set()
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def add_to_queue(self, room_id, events_and_contexts, backfilled):
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"""Add events to the queue, with the given persist_event options.
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NB: due to the normal usage pattern of this method, it does *not*
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follow the synapse logcontext rules, and leaves the logcontext in
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place whether or not the returned deferred is ready.
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Args:
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room_id (str):
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events_and_contexts (list[(EventBase, EventContext)]):
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backfilled (bool):
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Returns:
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defer.Deferred: a deferred which will resolve once the events are
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persisted. Runs its callbacks *without* a logcontext. The result
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is the same as that returned by the callback passed to
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`handle_queue`.
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"""
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queue = self._event_persist_queues.setdefault(room_id, deque())
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if queue:
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# if the last item in the queue has the same `backfilled` setting,
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# we can just add these new events to that item.
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end_item = queue[-1]
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if end_item.backfilled == backfilled:
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end_item.events_and_contexts.extend(events_and_contexts)
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return end_item.deferred.observe()
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deferred = ObservableDeferred(defer.Deferred(), consumeErrors=True)
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queue.append(
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self._EventPersistQueueItem(
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events_and_contexts=events_and_contexts,
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backfilled=backfilled,
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deferred=deferred,
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)
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)
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return deferred.observe()
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def handle_queue(self, room_id, per_item_callback):
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"""Attempts to handle the queue for a room if not already being handled.
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The given callback will be invoked with for each item in the queue,
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of type _EventPersistQueueItem. The per_item_callback will continuously
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be called with new items, unless the queue becomnes empty. The return
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value of the function will be given to the deferreds waiting on the item,
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exceptions will be passed to the deferreds as well.
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This function should therefore be called whenever anything is added
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to the queue.
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If another callback is currently handling the queue then it will not be
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invoked.
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"""
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if room_id in self._currently_persisting_rooms:
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return
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self._currently_persisting_rooms.add(room_id)
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async def handle_queue_loop():
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try:
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queue = self._get_drainining_queue(room_id)
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for item in queue:
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try:
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ret = await per_item_callback(item)
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except Exception:
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with PreserveLoggingContext():
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item.deferred.errback()
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else:
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with PreserveLoggingContext():
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item.deferred.callback(ret)
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finally:
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queue = self._event_persist_queues.pop(room_id, None)
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if queue:
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self._event_persist_queues[room_id] = queue
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self._currently_persisting_rooms.discard(room_id)
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# set handle_queue_loop off in the background
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run_as_background_process("persist_events", handle_queue_loop)
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def _get_drainining_queue(self, room_id):
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queue = self._event_persist_queues.setdefault(room_id, deque())
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try:
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while True:
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yield queue.popleft()
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except IndexError:
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# Queue has been drained.
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pass
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class EventsPersistenceStorage:
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"""High level interface for handling persisting newly received events.
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Takes care of batching up events by room, and calculating the necessary
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current state and forward extremity changes.
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"""
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def __init__(self, hs, stores: Databases):
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# We ultimately want to split out the state store from the main store,
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# so we use separate variables here even though they point to the same
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# store for now.
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self.main_store = stores.main
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self.state_store = stores.state
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assert stores.persist_events
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self.persist_events_store = stores.persist_events
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self._clock = hs.get_clock()
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self._instance_name = hs.get_instance_name()
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self.is_mine_id = hs.is_mine_id
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self._event_persist_queue = _EventPeristenceQueue()
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self._state_resolution_handler = hs.get_state_resolution_handler()
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async def persist_events(
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self,
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events_and_contexts: Iterable[Tuple[EventBase, EventContext]],
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backfilled: bool = False,
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) -> Tuple[List[EventBase], RoomStreamToken]:
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"""
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Write events to the database
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Args:
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events_and_contexts: list of tuples of (event, context)
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backfilled: Whether the results are retrieved from federation
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via backfill or not. Used to determine if they're "new" events
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which might update the current state etc.
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Returns:
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List of events persisted, the current position room stream position.
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The list of events persisted may not be the same as those passed in
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if they were deduplicated due to an event already existing that
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matched the transcation ID; the existing event is returned in such
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a case.
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"""
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partitioned = {} # type: Dict[str, List[Tuple[EventBase, EventContext]]]
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for event, ctx in events_and_contexts:
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partitioned.setdefault(event.room_id, []).append((event, ctx))
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deferreds = []
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for room_id, evs_ctxs in partitioned.items():
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d = self._event_persist_queue.add_to_queue(
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room_id, evs_ctxs, backfilled=backfilled
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)
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deferreds.append(d)
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for room_id in partitioned:
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self._maybe_start_persisting(room_id)
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# Each deferred returns a map from event ID to existing event ID if the
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# event was deduplicated. (The dict may also include other entries if
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# the event was persisted in a batch with other events).
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#
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# Since we use `defer.gatherResults` we need to merge the returned list
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# of dicts into one.
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ret_vals = await make_deferred_yieldable(
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defer.gatherResults(deferreds, consumeErrors=True)
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)
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replaced_events = {}
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for d in ret_vals:
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replaced_events.update(d)
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events = []
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for event, _ in events_and_contexts:
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existing_event_id = replaced_events.get(event.event_id)
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if existing_event_id:
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events.append(await self.main_store.get_event(existing_event_id))
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else:
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events.append(event)
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return (
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events,
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self.main_store.get_room_max_token(),
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)
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async def persist_event(
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self, event: EventBase, context: EventContext, backfilled: bool = False
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) -> Tuple[EventBase, PersistedEventPosition, RoomStreamToken]:
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"""
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Returns:
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The event, stream ordering of `event`, and the stream ordering of the
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latest persisted event. The returned event may not match the given
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event if it was deduplicated due to an existing event matching the
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transaction ID.
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"""
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deferred = self._event_persist_queue.add_to_queue(
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event.room_id, [(event, context)], backfilled=backfilled
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)
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self._maybe_start_persisting(event.room_id)
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# The deferred returns a map from event ID to existing event ID if the
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# event was deduplicated. (The dict may also include other entries if
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# the event was persisted in a batch with other events.)
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replaced_events = await make_deferred_yieldable(deferred)
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replaced_event = replaced_events.get(event.event_id)
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if replaced_event:
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event = await self.main_store.get_event(replaced_event)
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event_stream_id = event.internal_metadata.stream_ordering
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# stream ordering should have been assigned by now
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assert event_stream_id
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pos = PersistedEventPosition(self._instance_name, event_stream_id)
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return event, pos, self.main_store.get_room_max_token()
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def _maybe_start_persisting(self, room_id: str):
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"""Pokes the `_event_persist_queue` to start handling new items in the
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queue, if not already in progress.
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Causes the deferreds returned by `add_to_queue` to resolve with: a
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dictionary of event ID to event ID we didn't persist as we already had
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another event persisted with the same TXN ID.
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"""
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async def persisting_queue(item):
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with Measure(self._clock, "persist_events"):
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return await self._persist_events(
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item.events_and_contexts, backfilled=item.backfilled
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)
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self._event_persist_queue.handle_queue(room_id, persisting_queue)
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async def _persist_events(
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self,
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events_and_contexts: List[Tuple[EventBase, EventContext]],
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backfilled: bool = False,
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) -> Dict[str, str]:
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"""Calculates the change to current state and forward extremities, and
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persists the given events and with those updates.
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Returns:
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A dictionary of event ID to event ID we didn't persist as we already
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had another event persisted with the same TXN ID.
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"""
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replaced_events = {} # type: Dict[str, str]
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if not events_and_contexts:
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return replaced_events
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# Check if any of the events have a transaction ID that has already been
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# persisted, and if so we don't persist it again.
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#
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# We should have checked this a long time before we get here, but it's
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# possible that different send event requests race in such a way that
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# they both pass the earlier checks. Checking here isn't racey as we can
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# have only one `_persist_events` per room being called at a time.
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replaced_events = await self.main_store.get_already_persisted_events(
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(event for event, _ in events_and_contexts)
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)
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if replaced_events:
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events_and_contexts = [
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(e, ctx)
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for e, ctx in events_and_contexts
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if e.event_id not in replaced_events
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]
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if not events_and_contexts:
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return replaced_events
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chunks = [
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events_and_contexts[x : x + 100]
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for x in range(0, len(events_and_contexts), 100)
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]
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for chunk in chunks:
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# We can't easily parallelize these since different chunks
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# might contain the same event. :(
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# NB: Assumes that we are only persisting events for one room
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# at a time.
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# map room_id->list[event_ids] giving the new forward
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# extremities in each room
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new_forward_extremeties = {}
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# map room_id->(type,state_key)->event_id tracking the full
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# state in each room after adding these events.
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# This is simply used to prefill the get_current_state_ids
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# cache
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current_state_for_room = {}
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# map room_id->(to_delete, to_insert) where to_delete is a list
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# of type/state keys to remove from current state, and to_insert
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# is a map (type,key)->event_id giving the state delta in each
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# room
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state_delta_for_room = {}
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# Set of remote users which were in rooms the server has left. We
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# should check if we still share any rooms and if not we mark their
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# device lists as stale.
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potentially_left_users = set() # type: Set[str]
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if not backfilled:
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with Measure(self._clock, "_calculate_state_and_extrem"):
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# Work out the new "current state" for each room.
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# We do this by working out what the new extremities are and then
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# calculating the state from that.
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events_by_room = (
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{}
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) # type: Dict[str, List[Tuple[EventBase, EventContext]]]
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for event, context in chunk:
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events_by_room.setdefault(event.room_id, []).append(
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(event, context)
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)
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for room_id, ev_ctx_rm in events_by_room.items():
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latest_event_ids = await self.main_store.get_latest_event_ids_in_room(
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room_id
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)
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new_latest_event_ids = await self._calculate_new_extremities(
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room_id, ev_ctx_rm, latest_event_ids
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)
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latest_event_ids = set(latest_event_ids)
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if new_latest_event_ids == latest_event_ids:
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# No change in extremities, so no change in state
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continue
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# there should always be at least one forward extremity.
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# (except during the initial persistence of the send_join
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# results, in which case there will be no existing
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# extremities, so we'll `continue` above and skip this bit.)
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assert new_latest_event_ids, "No forward extremities left!"
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new_forward_extremeties[room_id] = new_latest_event_ids
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len_1 = (
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len(latest_event_ids) == 1
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and len(new_latest_event_ids) == 1
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)
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if len_1:
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all_single_prev_not_state = all(
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len(event.prev_event_ids()) == 1
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and not event.is_state()
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for event, ctx in ev_ctx_rm
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)
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# Don't bother calculating state if they're just
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# a long chain of single ancestor non-state events.
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if all_single_prev_not_state:
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continue
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state_delta_counter.inc()
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if len(new_latest_event_ids) == 1:
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state_delta_single_event_counter.inc()
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# This is a fairly handwavey check to see if we could
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# have guessed what the delta would have been when
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# processing one of these events.
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# What we're interested in is if the latest extremities
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# were the same when we created the event as they are
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# now. When this server creates a new event (as opposed
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# to receiving it over federation) it will use the
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# forward extremities as the prev_events, so we can
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# guess this by looking at the prev_events and checking
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# if they match the current forward extremities.
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for ev, _ in ev_ctx_rm:
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prev_event_ids = set(ev.prev_event_ids())
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if latest_event_ids == prev_event_ids:
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state_delta_reuse_delta_counter.inc()
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break
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logger.debug("Calculating state delta for room %s", room_id)
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with Measure(
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self._clock, "persist_events.get_new_state_after_events"
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):
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res = await self._get_new_state_after_events(
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room_id,
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ev_ctx_rm,
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latest_event_ids,
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new_latest_event_ids,
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)
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current_state, delta_ids = res
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# If either are not None then there has been a change,
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# and we need to work out the delta (or use that
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# given)
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delta = None
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if delta_ids is not None:
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# If there is a delta we know that we've
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# only added or replaced state, never
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# removed keys entirely.
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delta = DeltaState([], delta_ids)
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elif current_state is not None:
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with Measure(
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self._clock, "persist_events.calculate_state_delta"
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):
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delta = await self._calculate_state_delta(
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room_id, current_state
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)
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if delta:
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# If we have a change of state then lets check
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# whether we're actually still a member of the room,
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# or if our last user left. If we're no longer in
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# the room then we delete the current state and
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# extremities.
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is_still_joined = await self._is_server_still_joined(
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room_id,
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ev_ctx_rm,
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delta,
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current_state,
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potentially_left_users,
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)
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if not is_still_joined:
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logger.info("Server no longer in room %s", room_id)
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latest_event_ids = []
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current_state = {}
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delta.no_longer_in_room = True
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state_delta_for_room[room_id] = delta
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# If we have the current_state then lets prefill
|
|
# the cache with it.
|
|
if current_state is not None:
|
|
current_state_for_room[room_id] = current_state
|
|
|
|
await self.persist_events_store._persist_events_and_state_updates(
|
|
chunk,
|
|
current_state_for_room=current_state_for_room,
|
|
state_delta_for_room=state_delta_for_room,
|
|
new_forward_extremeties=new_forward_extremeties,
|
|
backfilled=backfilled,
|
|
)
|
|
|
|
await self._handle_potentially_left_users(potentially_left_users)
|
|
|
|
return replaced_events
|
|
|
|
async def _calculate_new_extremities(
|
|
self,
|
|
room_id: str,
|
|
event_contexts: List[Tuple[EventBase, EventContext]],
|
|
latest_event_ids: Collection[str],
|
|
):
|
|
"""Calculates the new forward extremities for a room given events to
|
|
persist.
|
|
|
|
Assumes that we are only persisting events for one room at a time.
|
|
"""
|
|
|
|
# we're only interested in new events which aren't outliers and which aren't
|
|
# being rejected.
|
|
new_events = [
|
|
event
|
|
for event, ctx in event_contexts
|
|
if not event.internal_metadata.is_outlier()
|
|
and not ctx.rejected
|
|
and not event.internal_metadata.is_soft_failed()
|
|
]
|
|
|
|
latest_event_ids = set(latest_event_ids)
|
|
|
|
# start with the existing forward extremities
|
|
result = set(latest_event_ids)
|
|
|
|
# add all the new events to the list
|
|
result.update(event.event_id for event in new_events)
|
|
|
|
# Now remove all events which are prev_events of any of the new events
|
|
result.difference_update(
|
|
e_id for event in new_events for e_id in event.prev_event_ids()
|
|
)
|
|
|
|
# Remove any events which are prev_events of any existing events.
|
|
existing_prevs = await self.persist_events_store._get_events_which_are_prevs(
|
|
result
|
|
) # type: Collection[str]
|
|
result.difference_update(existing_prevs)
|
|
|
|
# Finally handle the case where the new events have soft-failed prev
|
|
# events. If they do we need to remove them and their prev events,
|
|
# otherwise we end up with dangling extremities.
|
|
existing_prevs = await self.persist_events_store._get_prevs_before_rejected(
|
|
e_id for event in new_events for e_id in event.prev_event_ids()
|
|
)
|
|
result.difference_update(existing_prevs)
|
|
|
|
# We only update metrics for events that change forward extremities
|
|
# (e.g. we ignore backfill/outliers/etc)
|
|
if result != latest_event_ids:
|
|
forward_extremities_counter.observe(len(result))
|
|
stale = latest_event_ids & result
|
|
stale_forward_extremities_counter.observe(len(stale))
|
|
|
|
return result
|
|
|
|
async def _get_new_state_after_events(
|
|
self,
|
|
room_id: str,
|
|
events_context: List[Tuple[EventBase, EventContext]],
|
|
old_latest_event_ids: Iterable[str],
|
|
new_latest_event_ids: Iterable[str],
|
|
) -> Tuple[Optional[StateMap[str]], Optional[StateMap[str]]]:
|
|
"""Calculate the current state dict after adding some new events to
|
|
a room
|
|
|
|
Args:
|
|
room_id (str):
|
|
room to which the events are being added. Used for logging etc
|
|
|
|
events_context (list[(EventBase, EventContext)]):
|
|
events and contexts which are being added to the room
|
|
|
|
old_latest_event_ids (iterable[str]):
|
|
the old forward extremities for the room.
|
|
|
|
new_latest_event_ids (iterable[str]):
|
|
the new forward extremities for the room.
|
|
|
|
Returns:
|
|
Returns a tuple of two state maps, the first being the full new current
|
|
state and the second being the delta to the existing current state.
|
|
If both are None then there has been no change.
|
|
|
|
If there has been a change then we only return the delta if its
|
|
already been calculated. Conversely if we do know the delta then
|
|
the new current state is only returned if we've already calculated
|
|
it.
|
|
"""
|
|
# map from state_group to ((type, key) -> event_id) state map
|
|
state_groups_map = {}
|
|
|
|
# Map from (prev state group, new state group) -> delta state dict
|
|
state_group_deltas = {}
|
|
|
|
for ev, ctx in events_context:
|
|
if ctx.state_group is None:
|
|
# This should only happen for outlier events.
|
|
if not ev.internal_metadata.is_outlier():
|
|
raise Exception(
|
|
"Context for new event %s has no state "
|
|
"group" % (ev.event_id,)
|
|
)
|
|
continue
|
|
|
|
if ctx.state_group in state_groups_map:
|
|
continue
|
|
|
|
# We're only interested in pulling out state that has already
|
|
# been cached in the context. We'll pull stuff out of the DB later
|
|
# if necessary.
|
|
current_state_ids = ctx.get_cached_current_state_ids()
|
|
if current_state_ids is not None:
|
|
state_groups_map[ctx.state_group] = current_state_ids
|
|
|
|
if ctx.prev_group:
|
|
state_group_deltas[(ctx.prev_group, ctx.state_group)] = ctx.delta_ids
|
|
|
|
# We need to map the event_ids to their state groups. First, let's
|
|
# check if the event is one we're persisting, in which case we can
|
|
# pull the state group from its context.
|
|
# Otherwise we need to pull the state group from the database.
|
|
|
|
# Set of events we need to fetch groups for. (We know none of the old
|
|
# extremities are going to be in events_context).
|
|
missing_event_ids = set(old_latest_event_ids)
|
|
|
|
event_id_to_state_group = {}
|
|
for event_id in new_latest_event_ids:
|
|
# First search in the list of new events we're adding.
|
|
for ev, ctx in events_context:
|
|
if event_id == ev.event_id and ctx.state_group is not None:
|
|
event_id_to_state_group[event_id] = ctx.state_group
|
|
break
|
|
else:
|
|
# If we couldn't find it, then we'll need to pull
|
|
# the state from the database
|
|
missing_event_ids.add(event_id)
|
|
|
|
if missing_event_ids:
|
|
# Now pull out the state groups for any missing events from DB
|
|
event_to_groups = await self.main_store._get_state_group_for_events(
|
|
missing_event_ids
|
|
)
|
|
event_id_to_state_group.update(event_to_groups)
|
|
|
|
# State groups of old_latest_event_ids
|
|
old_state_groups = {
|
|
event_id_to_state_group[evid] for evid in old_latest_event_ids
|
|
}
|
|
|
|
# State groups of new_latest_event_ids
|
|
new_state_groups = {
|
|
event_id_to_state_group[evid] for evid in new_latest_event_ids
|
|
}
|
|
|
|
# If they old and new groups are the same then we don't need to do
|
|
# anything.
|
|
if old_state_groups == new_state_groups:
|
|
return None, None
|
|
|
|
if len(new_state_groups) == 1 and len(old_state_groups) == 1:
|
|
# If we're going from one state group to another, lets check if
|
|
# we have a delta for that transition. If we do then we can just
|
|
# return that.
|
|
|
|
new_state_group = next(iter(new_state_groups))
|
|
old_state_group = next(iter(old_state_groups))
|
|
|
|
delta_ids = state_group_deltas.get((old_state_group, new_state_group), None)
|
|
if delta_ids is not None:
|
|
# We have a delta from the existing to new current state,
|
|
# so lets just return that. If we happen to already have
|
|
# the current state in memory then lets also return that,
|
|
# but it doesn't matter if we don't.
|
|
new_state = state_groups_map.get(new_state_group)
|
|
return new_state, delta_ids
|
|
|
|
# Now that we have calculated new_state_groups we need to get
|
|
# their state IDs so we can resolve to a single state set.
|
|
missing_state = new_state_groups - set(state_groups_map)
|
|
if missing_state:
|
|
group_to_state = await self.state_store._get_state_for_groups(missing_state)
|
|
state_groups_map.update(group_to_state)
|
|
|
|
if len(new_state_groups) == 1:
|
|
# If there is only one state group, then we know what the current
|
|
# state is.
|
|
return state_groups_map[new_state_groups.pop()], None
|
|
|
|
# Ok, we need to defer to the state handler to resolve our state sets.
|
|
|
|
state_groups = {sg: state_groups_map[sg] for sg in new_state_groups}
|
|
|
|
events_map = {ev.event_id: ev for ev, _ in events_context}
|
|
|
|
# We need to get the room version, which is in the create event.
|
|
# Normally that'd be in the database, but its also possible that we're
|
|
# currently trying to persist it.
|
|
room_version = None
|
|
for ev, _ in events_context:
|
|
if ev.type == EventTypes.Create and ev.state_key == "":
|
|
room_version = ev.content.get("room_version", "1")
|
|
break
|
|
|
|
if not room_version:
|
|
room_version = await self.main_store.get_room_version_id(room_id)
|
|
|
|
logger.debug("calling resolve_state_groups from preserve_events")
|
|
|
|
# Avoid a circular import.
|
|
from synapse.state import StateResolutionStore
|
|
|
|
res = await self._state_resolution_handler.resolve_state_groups(
|
|
room_id,
|
|
room_version,
|
|
state_groups,
|
|
events_map,
|
|
state_res_store=StateResolutionStore(self.main_store),
|
|
)
|
|
|
|
return res.state, None
|
|
|
|
async def _calculate_state_delta(
|
|
self, room_id: str, current_state: StateMap[str]
|
|
) -> DeltaState:
|
|
"""Calculate the new state deltas for a room.
|
|
|
|
Assumes that we are only persisting events for one room at a time.
|
|
"""
|
|
existing_state = await self.main_store.get_current_state_ids(room_id)
|
|
|
|
to_delete = [key for key in existing_state if key not in current_state]
|
|
|
|
to_insert = {
|
|
key: ev_id
|
|
for key, ev_id in current_state.items()
|
|
if ev_id != existing_state.get(key)
|
|
}
|
|
|
|
return DeltaState(to_delete=to_delete, to_insert=to_insert)
|
|
|
|
async def _is_server_still_joined(
|
|
self,
|
|
room_id: str,
|
|
ev_ctx_rm: List[Tuple[EventBase, EventContext]],
|
|
delta: DeltaState,
|
|
current_state: Optional[StateMap[str]],
|
|
potentially_left_users: Set[str],
|
|
) -> bool:
|
|
"""Check if the server will still be joined after the given events have
|
|
been persised.
|
|
|
|
Args:
|
|
room_id
|
|
ev_ctx_rm
|
|
delta: The delta of current state between what is in the database
|
|
and what the new current state will be.
|
|
current_state: The new current state if it already been calculated,
|
|
otherwise None.
|
|
potentially_left_users: If the server has left the room, then joined
|
|
remote users will be added to this set to indicate that the
|
|
server may no longer be sharing a room with them.
|
|
"""
|
|
|
|
if not any(
|
|
self.is_mine_id(state_key)
|
|
for typ, state_key in itertools.chain(delta.to_delete, delta.to_insert)
|
|
if typ == EventTypes.Member
|
|
):
|
|
# There have been no changes to membership of our users, so nothing
|
|
# has changed and we assume we're still in the room.
|
|
return True
|
|
|
|
# Check if any of the given events are a local join that appear in the
|
|
# current state
|
|
events_to_check = [] # Event IDs that aren't an event we're persisting
|
|
for (typ, state_key), event_id in delta.to_insert.items():
|
|
if typ != EventTypes.Member or not self.is_mine_id(state_key):
|
|
continue
|
|
|
|
for event, _ in ev_ctx_rm:
|
|
if event_id == event.event_id:
|
|
if event.membership == Membership.JOIN:
|
|
return True
|
|
|
|
# The event is not in `ev_ctx_rm`, so we need to pull it out of
|
|
# the DB.
|
|
events_to_check.append(event_id)
|
|
|
|
# Check if any of the changes that we don't have events for are joins.
|
|
if events_to_check:
|
|
rows = await self.main_store.get_membership_from_event_ids(events_to_check)
|
|
is_still_joined = any(row["membership"] == Membership.JOIN for row in rows)
|
|
if is_still_joined:
|
|
return True
|
|
|
|
# None of the new state events are local joins, so we check the database
|
|
# to see if there are any other local users in the room. We ignore users
|
|
# whose state has changed as we've already their new state above.
|
|
users_to_ignore = [
|
|
state_key
|
|
for typ, state_key in itertools.chain(delta.to_insert, delta.to_delete)
|
|
if typ == EventTypes.Member and self.is_mine_id(state_key)
|
|
]
|
|
|
|
if await self.main_store.is_local_host_in_room_ignoring_users(
|
|
room_id, users_to_ignore
|
|
):
|
|
return True
|
|
|
|
# The server will leave the room, so we go and find out which remote
|
|
# users will still be joined when we leave.
|
|
if current_state is None:
|
|
current_state = await self.main_store.get_current_state_ids(room_id)
|
|
current_state = dict(current_state)
|
|
for key in delta.to_delete:
|
|
current_state.pop(key, None)
|
|
|
|
current_state.update(delta.to_insert)
|
|
|
|
remote_event_ids = [
|
|
event_id
|
|
for (typ, state_key,), event_id in current_state.items()
|
|
if typ == EventTypes.Member and not self.is_mine_id(state_key)
|
|
]
|
|
rows = await self.main_store.get_membership_from_event_ids(remote_event_ids)
|
|
potentially_left_users.update(
|
|
row["user_id"] for row in rows if row["membership"] == Membership.JOIN
|
|
)
|
|
|
|
return False
|
|
|
|
async def _handle_potentially_left_users(self, user_ids: Set[str]):
|
|
"""Given a set of remote users check if the server still shares a room with
|
|
them. If not then mark those users' device cache as stale.
|
|
"""
|
|
|
|
if not user_ids:
|
|
return
|
|
|
|
joined_users = await self.main_store.get_users_server_still_shares_room_with(
|
|
user_ids
|
|
)
|
|
left_users = user_ids - joined_users
|
|
|
|
for user_id in left_users:
|
|
await self.main_store.mark_remote_user_device_list_as_unsubscribed(user_id)
|