1081 lines
		
	
	
		
			43 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			1081 lines
		
	
	
		
			43 KiB
		
	
	
	
		
			Python
		
	
	
| # 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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| #     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
 | |
| import logging
 | |
| from collections import deque
 | |
| from typing import (
 | |
|     Any,
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|     Awaitable,
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|     Callable,
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|     Collection,
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|     Deque,
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|     Dict,
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|     Generic,
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|     Iterable,
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|     List,
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|     Optional,
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|     Set,
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|     Tuple,
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|     TypeVar,
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| )
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| 
 | |
| import attr
 | |
| 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
 | |
| from synapse.events import EventBase
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| from synapse.events.snapshot import EventContext
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| from synapse.logging import opentracing
 | |
| from synapse.logging.context import PreserveLoggingContext, make_deferred_yieldable
 | |
| from synapse.metrics.background_process_metrics import run_as_background_process
 | |
| from synapse.storage.databases import Databases
 | |
| from synapse.storage.databases.main.events import DeltaState
 | |
| from synapse.storage.databases.main.events_worker import EventRedactBehaviour
 | |
| from synapse.types import (
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|     PersistedEventPosition,
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|     RoomStreamToken,
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|     StateMap,
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|     get_domain_from_id,
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| )
 | |
| from synapse.util.async_helpers import ObservableDeferred, yieldable_gather_results
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| from synapse.util.metrics import Measure
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| 
 | |
| logger = logging.getLogger(__name__)
 | |
| 
 | |
| # 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
 | |
| # single forward extremity
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| state_delta_single_event_counter = Counter(
 | |
|     "synapse_storage_events_state_delta_single_event", ""
 | |
| )
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| 
 | |
| # The number of times we are reculating state when we could have resonably
 | |
| # 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(
 | |
|     "synapse_storage_events_state_delta_reuse_delta", ""
 | |
| )
 | |
| 
 | |
| # 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",
 | |
|     "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"),
 | |
| )
 | |
| 
 | |
| # The number of stale forward extremities for each new event. Stale extremities
 | |
| # are those that were in the previous set of extremities as well as the new.
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| stale_forward_extremities_counter = Histogram(
 | |
|     "synapse_storage_events_stale_forward_extremities_persisted",
 | |
|     "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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| 
 | |
| state_resolutions_during_persistence = Counter(
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|     "synapse_storage_events_state_resolutions_during_persistence",
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|     "Number of times we had to do state res to calculate new current state",
 | |
| )
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| 
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| potential_times_prune_extremities = Counter(
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|     "synapse_storage_events_potential_times_prune_extremities",
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|     "Number of times we might be able to prune extremities",
 | |
| )
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| 
 | |
| times_pruned_extremities = Counter(
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|     "synapse_storage_events_times_pruned_extremities",
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|     "Number of times we were actually be able to prune extremities",
 | |
| )
 | |
| 
 | |
| 
 | |
| @attr.s(auto_attribs=True, slots=True)
 | |
| class _EventPersistQueueItem:
 | |
|     events_and_contexts: List[Tuple[EventBase, EventContext]]
 | |
|     backfilled: bool
 | |
|     deferred: ObservableDeferred
 | |
| 
 | |
|     parent_opentracing_span_contexts: List = attr.ib(factory=list)
 | |
|     """A list of opentracing spans waiting for this batch"""
 | |
| 
 | |
|     opentracing_span_context: Any = None
 | |
|     """The opentracing span under which the persistence actually happened"""
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| 
 | |
| 
 | |
| _PersistResult = TypeVar("_PersistResult")
 | |
| 
 | |
| 
 | |
| class _EventPeristenceQueue(Generic[_PersistResult]):
 | |
|     """Queues up events so that they can be persisted in bulk with only one
 | |
|     concurrent transaction per room.
 | |
|     """
 | |
| 
 | |
|     def __init__(
 | |
|         self,
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|         per_item_callback: Callable[
 | |
|             [List[Tuple[EventBase, EventContext]], bool],
 | |
|             Awaitable[_PersistResult],
 | |
|         ],
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|     ):
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|         """Create a new event persistence queue
 | |
| 
 | |
|         The per_item_callback will be called for each item added via add_to_queue,
 | |
|         and its result will be returned via the Deferreds returned from add_to_queue.
 | |
|         """
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|         self._event_persist_queues: Dict[str, Deque[_EventPersistQueueItem]] = {}
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|         self._currently_persisting_rooms: Set[str] = set()
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|         self._per_item_callback = per_item_callback
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| 
 | |
|     async def add_to_queue(
 | |
|         self,
 | |
|         room_id: str,
 | |
|         events_and_contexts: Iterable[Tuple[EventBase, EventContext]],
 | |
|         backfilled: bool,
 | |
|     ) -> _PersistResult:
 | |
|         """Add events to the queue, with the given persist_event options.
 | |
| 
 | |
|         If we are not already processing events in this room, starts off a background
 | |
|         process to to so, calling the per_item_callback for each item.
 | |
| 
 | |
|         Args:
 | |
|             room_id (str):
 | |
|             events_and_contexts (list[(EventBase, EventContext)]):
 | |
|             backfilled (bool):
 | |
| 
 | |
|         Returns:
 | |
|             the result returned by the `_per_item_callback` passed to
 | |
|             `__init__`.
 | |
|         """
 | |
|         queue = self._event_persist_queues.setdefault(room_id, deque())
 | |
| 
 | |
|         # 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.
 | |
|         if queue and queue[-1].backfilled == backfilled:
 | |
|             end_item = queue[-1]
 | |
|         else:
 | |
|             # need to make a new queue item
 | |
|             deferred: ObservableDeferred[_PersistResult] = ObservableDeferred(
 | |
|                 defer.Deferred(), consumeErrors=True
 | |
|             )
 | |
| 
 | |
|             end_item = _EventPersistQueueItem(
 | |
|                 events_and_contexts=[],
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|                 backfilled=backfilled,
 | |
|                 deferred=deferred,
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|             )
 | |
|             queue.append(end_item)
 | |
| 
 | |
|         # add our events to the queue item
 | |
|         end_item.events_and_contexts.extend(events_and_contexts)
 | |
| 
 | |
|         # also add our active opentracing span to the item so that we get a link back
 | |
|         span = opentracing.active_span()
 | |
|         if span:
 | |
|             end_item.parent_opentracing_span_contexts.append(span.context)
 | |
| 
 | |
|         # start a processor for the queue, if there isn't one already
 | |
|         self._handle_queue(room_id)
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| 
 | |
|         # wait for the queue item to complete
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|         res = await make_deferred_yieldable(end_item.deferred.observe())
 | |
| 
 | |
|         # add another opentracing span which links to the persist trace.
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|         with opentracing.start_active_span_follows_from(
 | |
|             "persist_event_batch_complete", (end_item.opentracing_span_context,)
 | |
|         ):
 | |
|             pass
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| 
 | |
|         return res
 | |
| 
 | |
|     def _handle_queue(self, room_id):
 | |
|         """Attempts to handle the queue for a room if not already being handled.
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| 
 | |
|         The queue's callback will be invoked with for each item in the queue,
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|         of type _EventPersistQueueItem. The per_item_callback will continuously
 | |
|         be called with new items, unless the queue becomes empty. The return
 | |
|         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.
 | |
| 
 | |
|         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
 | |
|         invoked.
 | |
|         """
 | |
|         if room_id in self._currently_persisting_rooms:
 | |
|             return
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| 
 | |
|         self._currently_persisting_rooms.add(room_id)
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| 
 | |
|         async def handle_queue_loop():
 | |
|             try:
 | |
|                 queue = self._get_drainining_queue(room_id)
 | |
|                 for item in queue:
 | |
|                     try:
 | |
|                         with opentracing.start_active_span_follows_from(
 | |
|                             "persist_event_batch",
 | |
|                             item.parent_opentracing_span_contexts,
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|                             inherit_force_tracing=True,
 | |
|                         ) as scope:
 | |
|                             if scope:
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|                                 item.opentracing_span_context = scope.span.context
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| 
 | |
|                             ret = await self._per_item_callback(
 | |
|                                 item.events_and_contexts, item.backfilled
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|                             )
 | |
|                     except Exception:
 | |
|                         with PreserveLoggingContext():
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|                             item.deferred.errback()
 | |
|                     else:
 | |
|                         with PreserveLoggingContext():
 | |
|                             item.deferred.callback(ret)
 | |
|             finally:
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|                 queue = self._event_persist_queues.pop(room_id, None)
 | |
|                 if queue:
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|                     self._event_persist_queues[room_id] = queue
 | |
|                 self._currently_persisting_rooms.discard(room_id)
 | |
| 
 | |
|         # set handle_queue_loop off in the background
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|         run_as_background_process("persist_events", handle_queue_loop)
 | |
| 
 | |
|     def _get_drainining_queue(self, room_id):
 | |
|         queue = self._event_persist_queues.setdefault(room_id, deque())
 | |
| 
 | |
|         try:
 | |
|             while True:
 | |
|                 yield queue.popleft()
 | |
|         except IndexError:
 | |
|             # Queue has been drained.
 | |
|             pass
 | |
| 
 | |
| 
 | |
| class EventsPersistenceStorage:
 | |
|     """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.
 | |
|     """
 | |
| 
 | |
|     def __init__(self, hs, stores: Databases):
 | |
|         # We ultimately want to split out the state store from the main store,
 | |
|         # so we use separate variables here even though they point to the same
 | |
|         # store for now.
 | |
|         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
 | |
| 
 | |
|         self._clock = hs.get_clock()
 | |
|         self._instance_name = hs.get_instance_name()
 | |
|         self.is_mine_id = hs.is_mine_id
 | |
|         self._event_persist_queue = _EventPeristenceQueue(self._persist_event_batch)
 | |
|         self._state_resolution_handler = hs.get_state_resolution_handler()
 | |
| 
 | |
|     @opentracing.trace
 | |
|     async def persist_events(
 | |
|         self,
 | |
|         events_and_contexts: Iterable[Tuple[EventBase, EventContext]],
 | |
|         backfilled: bool = False,
 | |
|     ) -> Tuple[List[EventBase], RoomStreamToken]:
 | |
|         """
 | |
|         Write events to the database
 | |
|         Args:
 | |
|             events_and_contexts: list of tuples of (event, context)
 | |
|             backfilled: Whether the results are retrieved from federation
 | |
|                 via backfill or not. Used to determine if they're "new" events
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|                 which might update the current state etc.
 | |
| 
 | |
|         Returns:
 | |
|             List of events persisted, the current position room stream position.
 | |
|             The list of events persisted may not be the same as those passed in
 | |
|             if they were deduplicated due to an event already existing that
 | |
|             matched the transcation ID; the existing event is returned in such
 | |
|             a case.
 | |
|         """
 | |
|         partitioned: Dict[str, List[Tuple[EventBase, EventContext]]] = {}
 | |
|         for event, ctx in events_and_contexts:
 | |
|             partitioned.setdefault(event.room_id, []).append((event, ctx))
 | |
| 
 | |
|         async def enqueue(item):
 | |
|             room_id, evs_ctxs = item
 | |
|             return await self._event_persist_queue.add_to_queue(
 | |
|                 room_id, evs_ctxs, backfilled=backfilled
 | |
|             )
 | |
| 
 | |
|         ret_vals = await yieldable_gather_results(enqueue, partitioned.items())
 | |
| 
 | |
|         # Each call to add_to_queue returns a map from event ID to existing event ID if
 | |
|         # the event was deduplicated. (The dict may also include other entries if
 | |
|         # the event was persisted in a batch with other events).
 | |
|         #
 | |
|         # Since we use `yieldable_gather_results` we need to merge the returned list
 | |
|         # of dicts into one.
 | |
|         replaced_events: Dict[str, str] = {}
 | |
|         for d in ret_vals:
 | |
|             replaced_events.update(d)
 | |
| 
 | |
|         events = []
 | |
|         for event, _ in events_and_contexts:
 | |
|             existing_event_id = replaced_events.get(event.event_id)
 | |
|             if existing_event_id:
 | |
|                 events.append(await self.main_store.get_event(existing_event_id))
 | |
|             else:
 | |
|                 events.append(event)
 | |
| 
 | |
|         return (
 | |
|             events,
 | |
|             self.main_store.get_room_max_token(),
 | |
|         )
 | |
| 
 | |
|     @opentracing.trace
 | |
|     async def persist_event(
 | |
|         self, event: EventBase, context: EventContext, backfilled: bool = False
 | |
|     ) -> Tuple[EventBase, PersistedEventPosition, RoomStreamToken]:
 | |
|         """
 | |
|         Returns:
 | |
|             The event, stream ordering of `event`, and the stream ordering of the
 | |
|             latest persisted event. The returned event may not match the given
 | |
|             event if it was deduplicated due to an existing event matching the
 | |
|             transaction ID.
 | |
|         """
 | |
|         # add_to_queue returns a map from event ID to existing event ID if the
 | |
|         # event was deduplicated. (The dict may also include other entries if
 | |
|         # the event was persisted in a batch with other events.)
 | |
|         replaced_events = await self._event_persist_queue.add_to_queue(
 | |
|             event.room_id, [(event, context)], backfilled=backfilled
 | |
|         )
 | |
|         replaced_event = replaced_events.get(event.event_id)
 | |
|         if replaced_event:
 | |
|             event = await self.main_store.get_event(replaced_event)
 | |
| 
 | |
|         event_stream_id = event.internal_metadata.stream_ordering
 | |
|         # stream ordering should have been assigned by now
 | |
|         assert event_stream_id
 | |
| 
 | |
|         pos = PersistedEventPosition(self._instance_name, event_stream_id)
 | |
|         return event, pos, self.main_store.get_room_max_token()
 | |
| 
 | |
|     async def _persist_event_batch(
 | |
|         self,
 | |
|         events_and_contexts: List[Tuple[EventBase, EventContext]],
 | |
|         backfilled: bool = False,
 | |
|     ) -> Dict[str, str]:
 | |
|         """Callback for the _event_persist_queue
 | |
| 
 | |
|         Calculates the change to current state and forward extremities, and
 | |
|         persists the given events and with those updates.
 | |
| 
 | |
|         Returns:
 | |
|             A dictionary of event ID to event ID we didn't persist as we already
 | |
|             had another event persisted with the same TXN ID.
 | |
|         """
 | |
|         replaced_events: Dict[str, str] = {}
 | |
|         if not events_and_contexts:
 | |
|             return replaced_events
 | |
| 
 | |
|         # Check if any of the events have a transaction ID that has already been
 | |
|         # persisted, and if so we don't persist it again.
 | |
|         #
 | |
|         # We should have checked this a long time before we get here, but it's
 | |
|         # possible that different send event requests race in such a way that
 | |
|         # they both pass the earlier checks. Checking here isn't racey as we can
 | |
|         # have only one `_persist_events` per room being called at a time.
 | |
|         replaced_events = await self.main_store.get_already_persisted_events(
 | |
|             (event for event, _ in events_and_contexts)
 | |
|         )
 | |
| 
 | |
|         if replaced_events:
 | |
|             events_and_contexts = [
 | |
|                 (e, ctx)
 | |
|                 for e, ctx in events_and_contexts
 | |
|                 if e.event_id not in replaced_events
 | |
|             ]
 | |
| 
 | |
|             if not events_and_contexts:
 | |
|                 return replaced_events
 | |
| 
 | |
|         chunks = [
 | |
|             events_and_contexts[x : x + 100]
 | |
|             for x in range(0, len(events_and_contexts), 100)
 | |
|         ]
 | |
| 
 | |
|         for chunk in chunks:
 | |
|             # We can't easily parallelize these since different chunks
 | |
|             # might contain the same event. :(
 | |
| 
 | |
|             # NB: Assumes that we are only persisting events for one room
 | |
|             # at a time.
 | |
| 
 | |
|             # map room_id->list[event_ids] giving the new forward
 | |
|             # extremities in each room
 | |
|             new_forward_extremeties = {}
 | |
| 
 | |
|             # map room_id->(type,state_key)->event_id tracking the full
 | |
|             # state in each room after adding these events.
 | |
|             # This is simply used to prefill the get_current_state_ids
 | |
|             # cache
 | |
|             current_state_for_room = {}
 | |
| 
 | |
|             # map room_id->(to_delete, to_insert) where to_delete is a list
 | |
|             # of type/state keys to remove from current state, and to_insert
 | |
|             # is a map (type,key)->event_id giving the state delta in each
 | |
|             # room
 | |
|             state_delta_for_room = {}
 | |
| 
 | |
|             # Set of remote users which were in rooms the server has left. We
 | |
|             # should check if we still share any rooms and if not we mark their
 | |
|             # device lists as stale.
 | |
|             potentially_left_users: Set[str] = set()
 | |
| 
 | |
|             if not backfilled:
 | |
|                 with Measure(self._clock, "_calculate_state_and_extrem"):
 | |
|                     # Work out the new "current state" for each room.
 | |
|                     # We do this by working out what the new extremities are and then
 | |
|                     # calculating the state from that.
 | |
|                     events_by_room: Dict[str, List[Tuple[EventBase, EventContext]]] = {}
 | |
|                     for event, context in chunk:
 | |
|                         events_by_room.setdefault(event.room_id, []).append(
 | |
|                             (event, context)
 | |
|                         )
 | |
| 
 | |
|                     for room_id, ev_ctx_rm in events_by_room.items():
 | |
|                         latest_event_ids = (
 | |
|                             await self.main_store.get_latest_event_ids_in_room(room_id)
 | |
|                         )
 | |
|                         new_latest_event_ids = await self._calculate_new_extremities(
 | |
|                             room_id, ev_ctx_rm, latest_event_ids
 | |
|                         )
 | |
| 
 | |
|                         latest_event_ids = set(latest_event_ids)
 | |
|                         if new_latest_event_ids == latest_event_ids:
 | |
|                             # No change in extremities, so no change in state
 | |
|                             continue
 | |
| 
 | |
|                         # there should always be at least one forward extremity.
 | |
|                         # (except during the initial persistence of the send_join
 | |
|                         # results, in which case there will be no existing
 | |
|                         # extremities, so we'll `continue` above and skip this bit.)
 | |
|                         assert new_latest_event_ids, "No forward extremities left!"
 | |
| 
 | |
|                         new_forward_extremeties[room_id] = new_latest_event_ids
 | |
| 
 | |
|                         len_1 = (
 | |
|                             len(latest_event_ids) == 1
 | |
|                             and len(new_latest_event_ids) == 1
 | |
|                         )
 | |
|                         if len_1:
 | |
|                             all_single_prev_not_state = all(
 | |
|                                 len(event.prev_event_ids()) == 1
 | |
|                                 and not event.is_state()
 | |
|                                 for event, ctx in ev_ctx_rm
 | |
|                             )
 | |
|                             # Don't bother calculating state if they're just
 | |
|                             # a long chain of single ancestor non-state events.
 | |
|                             if all_single_prev_not_state:
 | |
|                                 continue
 | |
| 
 | |
|                         state_delta_counter.inc()
 | |
|                         if len(new_latest_event_ids) == 1:
 | |
|                             state_delta_single_event_counter.inc()
 | |
| 
 | |
|                             # This is a fairly handwavey check to see if we could
 | |
|                             # have guessed what the delta would have been when
 | |
|                             # processing one of these events.
 | |
|                             # What we're interested in is if the latest extremities
 | |
|                             # were the same when we created the event as they are
 | |
|                             # now. When this server creates a new event (as opposed
 | |
|                             # to receiving it over federation) it will use the
 | |
|                             # forward extremities as the prev_events, so we can
 | |
|                             # guess this by looking at the prev_events and checking
 | |
|                             # if they match the current forward extremities.
 | |
|                             for ev, _ in ev_ctx_rm:
 | |
|                                 prev_event_ids = set(ev.prev_event_ids())
 | |
|                                 if latest_event_ids == prev_event_ids:
 | |
|                                     state_delta_reuse_delta_counter.inc()
 | |
|                                     break
 | |
| 
 | |
|                         logger.debug("Calculating state delta for room %s", room_id)
 | |
|                         with Measure(
 | |
|                             self._clock, "persist_events.get_new_state_after_events"
 | |
|                         ):
 | |
|                             res = await self._get_new_state_after_events(
 | |
|                                 room_id,
 | |
|                                 ev_ctx_rm,
 | |
|                                 latest_event_ids,
 | |
|                                 new_latest_event_ids,
 | |
|                             )
 | |
|                             current_state, delta_ids, new_latest_event_ids = res
 | |
| 
 | |
|                             # there should always be at least one forward extremity.
 | |
|                             # (except during the initial persistence of the send_join
 | |
|                             # results, in which case there will be no existing
 | |
|                             # extremities, so we'll `continue` above and skip this bit.)
 | |
|                             assert new_latest_event_ids, "No forward extremities left!"
 | |
| 
 | |
|                             new_forward_extremeties[room_id] = new_latest_event_ids
 | |
| 
 | |
|                         # If either are not None then there has been a change,
 | |
|                         # and we need to work out the delta (or use that
 | |
|                         # given)
 | |
|                         delta = None
 | |
|                         if delta_ids is not None:
 | |
|                             # If there is a delta we know that we've
 | |
|                             # only added or replaced state, never
 | |
|                             # removed keys entirely.
 | |
|                             delta = DeltaState([], delta_ids)
 | |
|                         elif current_state is not None:
 | |
|                             with Measure(
 | |
|                                 self._clock, "persist_events.calculate_state_delta"
 | |
|                             ):
 | |
|                                 delta = await self._calculate_state_delta(
 | |
|                                     room_id, current_state
 | |
|                                 )
 | |
| 
 | |
|                         if delta:
 | |
|                             # If we have a change of state then lets check
 | |
|                             # whether we're actually still a member of the room,
 | |
|                             # or if our last user left. If we're no longer in
 | |
|                             # the room then we delete the current state and
 | |
|                             # extremities.
 | |
|                             is_still_joined = await self._is_server_still_joined(
 | |
|                                 room_id,
 | |
|                                 ev_ctx_rm,
 | |
|                                 delta,
 | |
|                                 current_state,
 | |
|                                 potentially_left_users,
 | |
|                             )
 | |
|                             if not is_still_joined:
 | |
|                                 logger.info("Server no longer in room %s", room_id)
 | |
|                                 latest_event_ids = []
 | |
|                                 current_state = {}
 | |
|                                 delta.no_longer_in_room = True
 | |
| 
 | |
|                             state_delta_for_room[room_id] = delta
 | |
| 
 | |
|                         # 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: Collection[
 | |
|             str
 | |
|         ] = await self.persist_events_store._get_events_which_are_prevs(result)
 | |
|         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: Set[str],
 | |
|         new_latest_event_ids: Set[str],
 | |
|     ) -> Tuple[Optional[StateMap[str]], Optional[StateMap[str]], Set[str]]:
 | |
|         """Calculate the current state dict after adding some new events to
 | |
|         a room
 | |
| 
 | |
|         Args:
 | |
|             room_id:
 | |
|                 room to which the events are being added. Used for logging etc
 | |
| 
 | |
|             events_context:
 | |
|                 events and contexts which are being added to the room
 | |
| 
 | |
|             old_latest_event_ids:
 | |
|                 the old forward extremities for the room.
 | |
| 
 | |
|             new_latest_event_ids :
 | |
|                 the new forward extremities for the room.
 | |
| 
 | |
|         Returns:
 | |
|             Returns a tuple of two state maps and a set of new forward
 | |
|             extremities.
 | |
| 
 | |
|             The first state map is the full new current state and the second
 | |
|             is the delta to the existing current state. If both are None then
 | |
|             there has been no change.
 | |
| 
 | |
|             The function may prune some old entries from the set of new
 | |
|             forward extremities if it's safe to do so.
 | |
| 
 | |
|             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, new_latest_event_ids
 | |
| 
 | |
|         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, new_latest_event_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, new_latest_event_ids
 | |
| 
 | |
|         # 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),
 | |
|         )
 | |
| 
 | |
|         state_resolutions_during_persistence.inc()
 | |
| 
 | |
|         # If the returned state matches the state group of one of the new
 | |
|         # forward extremities then we check if we are able to prune some state
 | |
|         # extremities.
 | |
|         if res.state_group and res.state_group in new_state_groups:
 | |
|             new_latest_event_ids = await self._prune_extremities(
 | |
|                 room_id,
 | |
|                 new_latest_event_ids,
 | |
|                 res.state_group,
 | |
|                 event_id_to_state_group,
 | |
|                 events_context,
 | |
|             )
 | |
| 
 | |
|         return res.state, None, new_latest_event_ids
 | |
| 
 | |
|     async def _prune_extremities(
 | |
|         self,
 | |
|         room_id: str,
 | |
|         new_latest_event_ids: Set[str],
 | |
|         resolved_state_group: int,
 | |
|         event_id_to_state_group: Dict[str, int],
 | |
|         events_context: List[Tuple[EventBase, EventContext]],
 | |
|     ) -> Set[str]:
 | |
|         """See if we can prune any of the extremities after calculating the
 | |
|         resolved state.
 | |
|         """
 | |
|         potential_times_prune_extremities.inc()
 | |
| 
 | |
|         # We keep all the extremities that have the same state group, and
 | |
|         # see if we can drop the others.
 | |
|         new_new_extrems = {
 | |
|             e
 | |
|             for e in new_latest_event_ids
 | |
|             if event_id_to_state_group[e] == resolved_state_group
 | |
|         }
 | |
| 
 | |
|         dropped_extrems = set(new_latest_event_ids) - new_new_extrems
 | |
| 
 | |
|         logger.debug("Might drop extremities: %s", dropped_extrems)
 | |
| 
 | |
|         # We only drop events from the extremities list if:
 | |
|         #   1. we're not currently persisting them;
 | |
|         #   2. they're not our own events (or are dummy events); and
 | |
|         #   3. they're either:
 | |
|         #       1. over N hours old and more than N events ago (we use depth to
 | |
|         #          calculate); or
 | |
|         #       2. we are persisting an event from the same domain and more than
 | |
|         #          M events ago.
 | |
|         #
 | |
|         # The idea is that we don't want to drop events that are "legitimate"
 | |
|         # extremities (that we would want to include as prev events), only
 | |
|         # "stuck" extremities that are e.g. due to a gap in the graph.
 | |
|         #
 | |
|         # Note that we either drop all of them or none of them. If we only drop
 | |
|         # some of the events we don't know if state res would come to the same
 | |
|         # conclusion.
 | |
| 
 | |
|         for ev, _ in events_context:
 | |
|             if ev.event_id in dropped_extrems:
 | |
|                 logger.debug(
 | |
|                     "Not dropping extremities: %s is being persisted", ev.event_id
 | |
|                 )
 | |
|                 return new_latest_event_ids
 | |
| 
 | |
|         dropped_events = await self.main_store.get_events(
 | |
|             dropped_extrems,
 | |
|             allow_rejected=True,
 | |
|             redact_behaviour=EventRedactBehaviour.AS_IS,
 | |
|         )
 | |
| 
 | |
|         new_senders = {get_domain_from_id(e.sender) for e, _ in events_context}
 | |
| 
 | |
|         one_day_ago = self._clock.time_msec() - 24 * 60 * 60 * 1000
 | |
|         current_depth = max(e.depth for e, _ in events_context)
 | |
|         for event in dropped_events.values():
 | |
|             # If the event is a local dummy event then we should check it
 | |
|             # doesn't reference any local events, as we want to reference those
 | |
|             # if we send any new events.
 | |
|             #
 | |
|             # Note we do this recursively to handle the case where a dummy event
 | |
|             # references a dummy event that only references remote events.
 | |
|             #
 | |
|             # Ideally we'd figure out a way of still being able to drop old
 | |
|             # dummy events that reference local events, but this is good enough
 | |
|             # as a first cut.
 | |
|             events_to_check = [event]
 | |
|             while events_to_check:
 | |
|                 new_events = set()
 | |
|                 for event_to_check in events_to_check:
 | |
|                     if self.is_mine_id(event_to_check.sender):
 | |
|                         if event_to_check.type != EventTypes.Dummy:
 | |
|                             logger.debug("Not dropping own event")
 | |
|                             return new_latest_event_ids
 | |
|                         new_events.update(event_to_check.prev_event_ids())
 | |
| 
 | |
|                 prev_events = await self.main_store.get_events(
 | |
|                     new_events,
 | |
|                     allow_rejected=True,
 | |
|                     redact_behaviour=EventRedactBehaviour.AS_IS,
 | |
|                 )
 | |
|                 events_to_check = prev_events.values()
 | |
| 
 | |
|             if (
 | |
|                 event.origin_server_ts < one_day_ago
 | |
|                 and event.depth < current_depth - 100
 | |
|             ):
 | |
|                 continue
 | |
| 
 | |
|             # We can be less conservative about dropping extremities from the
 | |
|             # same domain, though we do want to wait a little bit (otherwise
 | |
|             # we'll immediately remove all extremities from a given server).
 | |
|             if (
 | |
|                 get_domain_from_id(event.sender) in new_senders
 | |
|                 and event.depth < current_depth - 20
 | |
|             ):
 | |
|                 continue
 | |
| 
 | |
|             logger.debug(
 | |
|                 "Not dropping as too new and not in new_senders: %s",
 | |
|                 new_senders,
 | |
|             )
 | |
| 
 | |
|             return new_latest_event_ids
 | |
| 
 | |
|         times_pruned_extremities.inc()
 | |
| 
 | |
|         logger.info(
 | |
|             "Pruning forward extremities in room %s: from %s -> %s",
 | |
|             room_id,
 | |
|             new_latest_event_ids,
 | |
|             new_new_extrems,
 | |
|         )
 | |
|         return new_new_extrems
 | |
| 
 | |
|     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)
 |