916 lines
		
	
	
		
			33 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			916 lines
		
	
	
		
			33 KiB
		
	
	
	
		
			Python
		
	
	
# Copyright 2014-2016 OpenMarket Ltd
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# Copyright 2018 New Vector Ltd
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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 heapq
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import logging
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from collections import ChainMap, defaultdict
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from typing import (
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    TYPE_CHECKING,
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    Any,
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    Awaitable,
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    Callable,
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    Collection,
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    DefaultDict,
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    Dict,
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    FrozenSet,
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    List,
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    Mapping,
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    Optional,
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    Sequence,
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    Set,
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    Tuple,
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)
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import attr
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from immutabledict import immutabledict
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from prometheus_client import Counter, Histogram
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from synapse.api.constants import EventTypes
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from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, StateResolutionVersions
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from synapse.events import EventBase
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from synapse.events.snapshot import (
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    EventContext,
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    UnpersistedEventContext,
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    UnpersistedEventContextBase,
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)
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from synapse.logging.context import ContextResourceUsage
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from synapse.replication.http.state import ReplicationUpdateCurrentStateRestServlet
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from synapse.state import v1, v2
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from synapse.storage.databases.main.events_worker import EventRedactBehaviour
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from synapse.types import StateMap
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from synapse.types.state import StateFilter
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from synapse.util.async_helpers import Linearizer
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from synapse.util.caches.expiringcache import ExpiringCache
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from synapse.util.metrics import Measure, measure_func
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if TYPE_CHECKING:
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    from synapse.server import HomeServer
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    from synapse.storage.controllers import StateStorageController
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    from synapse.storage.databases.main import DataStore
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logger = logging.getLogger(__name__)
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metrics_logger = logging.getLogger("synapse.state.metrics")
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# Metrics for number of state groups involved in a resolution.
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state_groups_histogram = Histogram(
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    "synapse_state_number_state_groups_in_resolution",
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    "Number of state groups used when performing a state resolution",
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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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EVICTION_TIMEOUT_SECONDS = 60 * 60
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_NEXT_STATE_ID = 1
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POWER_KEY = (EventTypes.PowerLevels, "")
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def _gen_state_id() -> str:
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    global _NEXT_STATE_ID
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    s = "X%d" % (_NEXT_STATE_ID,)
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    _NEXT_STATE_ID += 1
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    return s
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class _StateCacheEntry:
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    __slots__ = ["_state", "state_group", "prev_group", "delta_ids"]
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    def __init__(
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        self,
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        state: Optional[StateMap[str]],
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        state_group: Optional[int],
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        prev_group: Optional[int] = None,
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        delta_ids: Optional[StateMap[str]] = None,
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    ):
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        if state is None and state_group is None and prev_group is None:
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            raise Exception("One of state, state_group or prev_group must be not None")
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        if prev_group is not None and delta_ids is None:
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            raise Exception("If prev_group is set so must delta_ids")
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        # A map from (type, state_key) to event_id.
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        #
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        # This can be None if we have a `state_group` (as then we can fetch the
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        # state from the DB.)
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        self._state: Optional[StateMap[str]] = (
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            immutabledict(state) if state is not None else None
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        )
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        # the ID of a state group if one and only one is involved.
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        # otherwise, None otherwise?
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        self.state_group = state_group
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        self.prev_group = prev_group
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        self.delta_ids: Optional[StateMap[str]] = (
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            immutabledict(delta_ids) if delta_ids is not None else None
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        )
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    async def get_state(
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        self,
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        state_storage: "StateStorageController",
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        state_filter: Optional["StateFilter"] = None,
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    ) -> StateMap[str]:
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        """Get the state map for this entry, either from the in-memory state or
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        looking up the state group in the DB.
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        """
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        if self._state is not None:
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            return self._state
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        if self.state_group is not None:
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            return await state_storage.get_state_ids_for_group(
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                self.state_group, state_filter
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            )
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        assert self.prev_group is not None and self.delta_ids is not None
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        prev_state = await state_storage.get_state_ids_for_group(
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            self.prev_group, state_filter
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        )
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        # ChainMap expects MutableMapping, but since we're using it immutably
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        # its safe to give it immutable maps.
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        return ChainMap(self.delta_ids, prev_state)  # type: ignore[arg-type]
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    def set_state_group(self, state_group: int) -> None:
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        """Update the state group assigned to this state (e.g. after we've
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        persisted it).
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        Note: this will cause the cache entry to drop any stored state.
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        """
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        self.state_group = state_group
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        # We clear out the state as we know longer need to explicitly keep it in
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        # the `state_cache` (as the store state group cache will do that).
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        self._state = None
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    def __len__(self) -> int:
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        # The len should be used to estimate how large this cache entry is, for
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        # cache eviction purposes. This is why it's fine to return 1 if we're
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        # not storing any state.
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        length = 0
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        if self._state:
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            length += len(self._state)
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        if self.delta_ids:
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            length += len(self.delta_ids)
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        return length or 1  # Make sure its not 0.
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class StateHandler:
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    """Fetches bits of state from the stores, and does state resolution
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    where necessary
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    """
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    def __init__(self, hs: "HomeServer"):
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        self.clock = hs.get_clock()
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        self.store = hs.get_datastores().main
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        self._state_storage_controller = hs.get_storage_controllers().state
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        self.hs = hs
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        self._state_resolution_handler = hs.get_state_resolution_handler()
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        self._storage_controllers = hs.get_storage_controllers()
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        self._events_shard_config = hs.config.worker.events_shard_config
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        self._instance_name = hs.get_instance_name()
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        self._update_current_state_client = (
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            ReplicationUpdateCurrentStateRestServlet.make_client(hs)
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        )
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    async def compute_state_after_events(
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        self,
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        room_id: str,
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        event_ids: Collection[str],
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        state_filter: Optional[StateFilter] = None,
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        await_full_state: bool = True,
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    ) -> StateMap[str]:
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        """Fetch the state after each of the given event IDs. Resolve them and return.
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        This is typically used where `event_ids` is a collection of forward extremities
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        in a room, intended to become the `prev_events` of a new event E. If so, the
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        return value of this function represents the state before E.
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        Args:
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            room_id: the room_id containing the given events.
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            event_ids: the events whose state should be fetched and resolved.
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            await_full_state: if `True`, will block if we do not yet have complete state
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                at these events and `state_filter` is not satisfied by partial state.
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                Defaults to `True`.
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        Returns:
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            the state dict (a mapping from (event_type, state_key) -> event_id) which
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            holds the resolution of the states after the given event IDs.
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        """
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        logger.debug("calling resolve_state_groups from compute_state_after_events")
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        if (
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            await_full_state
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            and state_filter
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            and not state_filter.must_await_full_state(self.hs.is_mine_id)
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        ):
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            await_full_state = False
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        ret = await self.resolve_state_groups_for_events(
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            room_id, event_ids, await_full_state
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        )
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        return await ret.get_state(self._state_storage_controller, state_filter)
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    async def get_current_user_ids_in_room(
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        self, room_id: str, latest_event_ids: Collection[str]
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    ) -> Set[str]:
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        """
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        Get the users IDs who are currently in a room.
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        Note: This is much slower than using the equivalent method
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        `DataStore.get_users_in_room` or `DataStore.get_users_in_room_with_profiles`,
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        so this should only be used when wanting the users at a particular point
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        in the room.
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        Args:
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            room_id: The ID of the room.
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            latest_event_ids: Precomputed list of latest event IDs. Will be computed if None.
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        Returns:
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            Set of user IDs in the room.
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        """
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        assert latest_event_ids is not None
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        logger.debug("calling resolve_state_groups from get_current_user_ids_in_room")
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        entry = await self.resolve_state_groups_for_events(room_id, latest_event_ids)
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        state = await entry.get_state(self._state_storage_controller, StateFilter.all())
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        return await self.store.get_joined_user_ids_from_state(room_id, state)
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    async def get_hosts_in_room_at_events(
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        self, room_id: str, event_ids: Collection[str]
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    ) -> FrozenSet[str]:
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        """Get the hosts that were in a room at the given event ids
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        Args:
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            room_id:
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            event_ids:
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        Returns:
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            The hosts in the room at the given events
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        """
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        entry = await self.resolve_state_groups_for_events(room_id, event_ids)
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        state = await entry.get_state(self._state_storage_controller, StateFilter.all())
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        return await self.store.get_joined_hosts(room_id, state, entry)
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    async def calculate_context_info(
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        self,
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        event: EventBase,
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        state_ids_before_event: Optional[StateMap[str]] = None,
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        partial_state: Optional[bool] = None,
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        state_group_before_event: Optional[int] = None,
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    ) -> UnpersistedEventContextBase:
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        """
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        Calulates the contents of an unpersisted event context, other than the current
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        state group (which is either provided or calculated when the event context is persisted)
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        state_ids_before_event:
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            The event ids of the full state before the event if
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            it can't be calculated from existing events. This is normally
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            only specified when receiving an event from federation where we
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            don't have the prev events, e.g. when backfilling or when the event
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            is being created for batch persisting.
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        partial_state:
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            `True` if `state_ids_before_event` is partial and omits non-critical
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            membership events.
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            `False` if `state_ids_before_event` is the full state.
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            `None` when `state_ids_before_event` is not provided. In this case, the
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            flag will be calculated based on `event`'s prev events.
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        state_group_before_event:
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            the current state group at the time of event, if known
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        Returns:
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            The event context.
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        Raises:
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            RuntimeError if `state_ids_before_event` is not provided and one or more
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                prev events are missing or outliers.
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        """
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        assert not event.internal_metadata.is_outlier()
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        #
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        # first of all, figure out the state before the event, unless we
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        # already have it.
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        #
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        if state_ids_before_event:
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            # if we're given the state before the event, then we use that
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            state_group_before_event_prev_group = None
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            deltas_to_state_group_before_event = None
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            # the partial_state flag must be provided
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            assert partial_state is not None
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        else:
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            # otherwise, we'll need to resolve the state across the prev_events.
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            # partial_state should not be set explicitly in this case:
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            # we work it out dynamically
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            assert partial_state is None
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            # if any of the prev-events have partial state, so do we.
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            # (This is slightly racy - the prev-events might get fixed up before we use
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            # their states - but I don't think that really matters; it just means we
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            # might redundantly recalculate the state for this event later.)
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            prev_event_ids = event.prev_event_ids()
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            incomplete_prev_events = await self.store.get_partial_state_events(
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                prev_event_ids
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            )
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            partial_state = any(incomplete_prev_events.values())
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            if partial_state:
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                logger.debug(
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                    "New/incoming event %s refers to prev_events %s with partial state",
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                    event.event_id,
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                    [k for (k, v) in incomplete_prev_events.items() if v],
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                )
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            logger.debug("calling resolve_state_groups from compute_event_context")
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            # we've already taken into account partial state, so no need to wait for
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            # complete state here.
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            entry = await self.resolve_state_groups_for_events(
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                event.room_id,
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                event.prev_event_ids(),
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                await_full_state=False,
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            )
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            state_group_before_event_prev_group = entry.prev_group
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            deltas_to_state_group_before_event = entry.delta_ids
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            state_ids_before_event = None
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            # We make sure that we have a state group assigned to the state.
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            if entry.state_group is None:
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                # store_state_group requires us to have either a previous state group
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                # (with deltas) or the complete state map. So, if we don't have a
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                # previous state group, load the complete state map now.
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                if state_group_before_event_prev_group is None:
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                    state_ids_before_event = await entry.get_state(
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                        self._state_storage_controller, StateFilter.all()
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                    )
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                state_group_before_event = (
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                    await self._state_storage_controller.store_state_group(
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						|
                        event.event_id,
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                        event.room_id,
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                        prev_group=state_group_before_event_prev_group,
 | 
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                        delta_ids=deltas_to_state_group_before_event,
 | 
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                        current_state_ids=state_ids_before_event,
 | 
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                    )
 | 
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                )
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                entry.set_state_group(state_group_before_event)
 | 
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            else:
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                state_group_before_event = entry.state_group
 | 
						|
 | 
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        #
 | 
						|
        # now if it's not a state event, we're done
 | 
						|
        #
 | 
						|
 | 
						|
        if not event.is_state():
 | 
						|
            return UnpersistedEventContext(
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                storage=self._storage_controllers,
 | 
						|
                state_group_before_event=state_group_before_event,
 | 
						|
                state_group_after_event=state_group_before_event,
 | 
						|
                state_delta_due_to_event={},
 | 
						|
                prev_group_for_state_group_before_event=state_group_before_event_prev_group,
 | 
						|
                delta_ids_to_state_group_before_event=deltas_to_state_group_before_event,
 | 
						|
                partial_state=partial_state,
 | 
						|
                state_map_before_event=state_ids_before_event,
 | 
						|
            )
 | 
						|
 | 
						|
        #
 | 
						|
        # otherwise, we'll need to set up creating a new state group for after the event
 | 
						|
        #
 | 
						|
 | 
						|
        key = (event.type, event.state_key)
 | 
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						|
        if state_ids_before_event is not None:
 | 
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            replaces = state_ids_before_event.get(key)
 | 
						|
        else:
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            replaces_state_map = await entry.get_state(
 | 
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                self._state_storage_controller, StateFilter.from_types([key])
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            )
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						|
            replaces = replaces_state_map.get(key)
 | 
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 | 
						|
        if replaces and replaces != event.event_id:
 | 
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            event.unsigned["replaces_state"] = replaces
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        delta_ids = {key: event.event_id}
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						|
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						|
        return UnpersistedEventContext(
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            storage=self._storage_controllers,
 | 
						|
            state_group_before_event=state_group_before_event,
 | 
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            state_group_after_event=None,
 | 
						|
            state_delta_due_to_event=delta_ids,
 | 
						|
            prev_group_for_state_group_before_event=state_group_before_event_prev_group,
 | 
						|
            delta_ids_to_state_group_before_event=deltas_to_state_group_before_event,
 | 
						|
            partial_state=partial_state,
 | 
						|
            state_map_before_event=state_ids_before_event,
 | 
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        )
 | 
						|
 | 
						|
    async def compute_event_context(
 | 
						|
        self,
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        event: EventBase,
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        state_ids_before_event: Optional[StateMap[str]] = None,
 | 
						|
        partial_state: Optional[bool] = None,
 | 
						|
    ) -> EventContext:
 | 
						|
        """Build an EventContext structure for a non-outlier event.
 | 
						|
 | 
						|
        (for an outlier, call EventContext.for_outlier directly)
 | 
						|
 | 
						|
        This works out what the current state should be for the event, and
 | 
						|
        generates a new state group if necessary.
 | 
						|
 | 
						|
        Args:
 | 
						|
            event:
 | 
						|
            state_ids_before_event: The event ids of the state before the event if
 | 
						|
                it can't be calculated from existing events. This is normally
 | 
						|
                only specified when receiving an event from federation where we
 | 
						|
                don't have the prev events, e.g. when backfilling.
 | 
						|
            partial_state:
 | 
						|
                `True` if `state_ids_before_event` is partial and omits non-critical
 | 
						|
                membership events.
 | 
						|
                `False` if `state_ids_before_event` is the full state.
 | 
						|
                `None` when `state_ids_before_event` is not provided. In this case, the
 | 
						|
                flag will be calculated based on `event`'s prev events.
 | 
						|
            entry:
 | 
						|
                A state cache entry for the resolved state across the prev events. We may
 | 
						|
                have already calculated this, so if it's available pass it in
 | 
						|
        Returns:
 | 
						|
            The event context.
 | 
						|
 | 
						|
        Raises:
 | 
						|
            RuntimeError if `state_ids_before_event` is not provided and one or more
 | 
						|
                prev events are missing or outliers.
 | 
						|
        """
 | 
						|
 | 
						|
        unpersisted_context = await self.calculate_context_info(
 | 
						|
            event=event,
 | 
						|
            state_ids_before_event=state_ids_before_event,
 | 
						|
            partial_state=partial_state,
 | 
						|
        )
 | 
						|
 | 
						|
        return await unpersisted_context.persist(event)
 | 
						|
 | 
						|
    @measure_func()
 | 
						|
    async def resolve_state_groups_for_events(
 | 
						|
        self, room_id: str, event_ids: Collection[str], await_full_state: bool = True
 | 
						|
    ) -> _StateCacheEntry:
 | 
						|
        """Given a list of event_ids this method fetches the state at each
 | 
						|
        event, resolves conflicts between them and returns them.
 | 
						|
 | 
						|
        Args:
 | 
						|
            room_id
 | 
						|
            event_ids
 | 
						|
            await_full_state: if true, will block if we do not yet have complete
 | 
						|
               state at these events.
 | 
						|
 | 
						|
        Returns:
 | 
						|
            The resolved state
 | 
						|
 | 
						|
        Raises:
 | 
						|
            RuntimeError if we don't have a state group for one or more of the events
 | 
						|
               (ie. they are outliers or unknown)
 | 
						|
        """
 | 
						|
        logger.debug("resolve_state_groups event_ids %s", event_ids)
 | 
						|
 | 
						|
        state_groups = await self._state_storage_controller.get_state_group_for_events(
 | 
						|
            event_ids, await_full_state=await_full_state
 | 
						|
        )
 | 
						|
 | 
						|
        state_group_ids = state_groups.values()
 | 
						|
 | 
						|
        # check if each event has same state group id, if so there's no state to resolve
 | 
						|
        state_group_ids_set = set(state_group_ids)
 | 
						|
        if len(state_group_ids_set) == 1:
 | 
						|
            (state_group_id,) = state_group_ids_set
 | 
						|
            (
 | 
						|
                prev_group,
 | 
						|
                delta_ids,
 | 
						|
            ) = await self._state_storage_controller.get_state_group_delta(
 | 
						|
                state_group_id
 | 
						|
            )
 | 
						|
            return _StateCacheEntry(
 | 
						|
                state=None,
 | 
						|
                state_group=state_group_id,
 | 
						|
                prev_group=prev_group,
 | 
						|
                delta_ids=delta_ids,
 | 
						|
            )
 | 
						|
        elif len(state_group_ids_set) == 0:
 | 
						|
            return _StateCacheEntry(state={}, state_group=None)
 | 
						|
 | 
						|
        room_version = await self.store.get_room_version_id(room_id)
 | 
						|
 | 
						|
        state_to_resolve = await self._state_storage_controller.get_state_for_groups(
 | 
						|
            state_group_ids_set
 | 
						|
        )
 | 
						|
 | 
						|
        result = await self._state_resolution_handler.resolve_state_groups(
 | 
						|
            room_id,
 | 
						|
            room_version,
 | 
						|
            state_to_resolve,
 | 
						|
            None,
 | 
						|
            state_res_store=StateResolutionStore(self.store),
 | 
						|
        )
 | 
						|
        return result
 | 
						|
 | 
						|
    async def update_current_state(self, room_id: str) -> None:
 | 
						|
        """Recalculates the current state for a room, and persists it.
 | 
						|
 | 
						|
        Raises:
 | 
						|
            SynapseError(502): if all attempts to connect to the event persister worker
 | 
						|
                fail
 | 
						|
        """
 | 
						|
        writer_instance = self._events_shard_config.get_instance(room_id)
 | 
						|
        if writer_instance != self._instance_name:
 | 
						|
            await self._update_current_state_client(
 | 
						|
                instance_name=writer_instance,
 | 
						|
                room_id=room_id,
 | 
						|
            )
 | 
						|
            return
 | 
						|
 | 
						|
        assert self._storage_controllers.persistence is not None
 | 
						|
        await self._storage_controllers.persistence.update_current_state(room_id)
 | 
						|
 | 
						|
 | 
						|
@attr.s(slots=True, auto_attribs=True)
 | 
						|
class _StateResMetrics:
 | 
						|
    """Keeps track of some usage metrics about state res."""
 | 
						|
 | 
						|
    # System and User CPU time, in seconds
 | 
						|
    cpu_time: float = 0.0
 | 
						|
 | 
						|
    # time spent on database transactions (excluding scheduling time). This roughly
 | 
						|
    # corresponds to the amount of work done on the db server, excluding event fetches.
 | 
						|
    db_time: float = 0.0
 | 
						|
 | 
						|
    # number of events fetched from the db.
 | 
						|
    db_events: int = 0
 | 
						|
 | 
						|
 | 
						|
_biggest_room_by_cpu_counter = Counter(
 | 
						|
    "synapse_state_res_cpu_for_biggest_room_seconds",
 | 
						|
    "CPU time spent performing state resolution for the single most expensive "
 | 
						|
    "room for state resolution",
 | 
						|
)
 | 
						|
_biggest_room_by_db_counter = Counter(
 | 
						|
    "synapse_state_res_db_for_biggest_room_seconds",
 | 
						|
    "Database time spent performing state resolution for the single most "
 | 
						|
    "expensive room for state resolution",
 | 
						|
)
 | 
						|
 | 
						|
_cpu_times = Histogram(
 | 
						|
    "synapse_state_res_cpu_for_all_rooms_seconds",
 | 
						|
    "CPU time (utime+stime) spent computing a single state resolution",
 | 
						|
)
 | 
						|
_db_times = Histogram(
 | 
						|
    "synapse_state_res_db_for_all_rooms_seconds",
 | 
						|
    "Database time spent computing a single state resolution",
 | 
						|
)
 | 
						|
 | 
						|
 | 
						|
class StateResolutionHandler:
 | 
						|
    """Responsible for doing state conflict resolution.
 | 
						|
 | 
						|
    Note that the storage layer depends on this handler, so all functions must
 | 
						|
    be storage-independent.
 | 
						|
    """
 | 
						|
 | 
						|
    def __init__(self, hs: "HomeServer"):
 | 
						|
        self.clock = hs.get_clock()
 | 
						|
 | 
						|
        self.resolve_linearizer = Linearizer(name="state_resolve_lock")
 | 
						|
 | 
						|
        # dict of set of event_ids -> _StateCacheEntry.
 | 
						|
        self._state_cache: ExpiringCache[
 | 
						|
            FrozenSet[int], _StateCacheEntry
 | 
						|
        ] = ExpiringCache(
 | 
						|
            cache_name="state_cache",
 | 
						|
            clock=self.clock,
 | 
						|
            max_len=100000,
 | 
						|
            expiry_ms=EVICTION_TIMEOUT_SECONDS * 1000,
 | 
						|
            iterable=True,
 | 
						|
            reset_expiry_on_get=True,
 | 
						|
        )
 | 
						|
 | 
						|
        #
 | 
						|
        # stuff for tracking time spent on state-res by room
 | 
						|
        #
 | 
						|
 | 
						|
        # tracks the amount of work done on state res per room
 | 
						|
        self._state_res_metrics: DefaultDict[str, _StateResMetrics] = defaultdict(
 | 
						|
            _StateResMetrics
 | 
						|
        )
 | 
						|
 | 
						|
        self.clock.looping_call(self._report_metrics, 120 * 1000)
 | 
						|
 | 
						|
    async def resolve_state_groups(
 | 
						|
        self,
 | 
						|
        room_id: str,
 | 
						|
        room_version: str,
 | 
						|
        state_groups_ids: Mapping[int, StateMap[str]],
 | 
						|
        event_map: Optional[Dict[str, EventBase]],
 | 
						|
        state_res_store: "StateResolutionStore",
 | 
						|
    ) -> _StateCacheEntry:
 | 
						|
        """Resolves conflicts between a set of state groups
 | 
						|
 | 
						|
        Always generates a new state group (unless we hit the cache), so should
 | 
						|
        not be called for a single state group
 | 
						|
 | 
						|
        Args:
 | 
						|
            room_id: room we are resolving for (used for logging and sanity checks)
 | 
						|
            room_version: version of the room
 | 
						|
            state_groups_ids:
 | 
						|
                A map from state group id to the state in that state group
 | 
						|
                (where 'state' is a map from state key to event id)
 | 
						|
 | 
						|
            event_map:
 | 
						|
                a dict from event_id to event, for any events that we happen to
 | 
						|
                have in flight (eg, those currently being persisted). This will be
 | 
						|
                used as a starting point for finding the state we need; any missing
 | 
						|
                events will be requested via state_res_store.
 | 
						|
 | 
						|
                If None, all events will be fetched via state_res_store.
 | 
						|
 | 
						|
            state_res_store
 | 
						|
 | 
						|
        Returns:
 | 
						|
            The resolved state
 | 
						|
        """
 | 
						|
        group_names = frozenset(state_groups_ids.keys())
 | 
						|
 | 
						|
        async with self.resolve_linearizer.queue(group_names):
 | 
						|
            cache = self._state_cache.get(group_names, None)
 | 
						|
            if cache:
 | 
						|
                return cache
 | 
						|
 | 
						|
            logger.info(
 | 
						|
                "Resolving state for %s with groups %s",
 | 
						|
                room_id,
 | 
						|
                list(group_names),
 | 
						|
            )
 | 
						|
 | 
						|
            state_groups_histogram.observe(len(state_groups_ids))
 | 
						|
 | 
						|
            new_state = await self.resolve_events_with_store(
 | 
						|
                room_id,
 | 
						|
                room_version,
 | 
						|
                list(state_groups_ids.values()),
 | 
						|
                event_map=event_map,
 | 
						|
                state_res_store=state_res_store,
 | 
						|
            )
 | 
						|
 | 
						|
            # if the new state matches any of the input state groups, we can
 | 
						|
            # use that state group again. Otherwise we will generate a state_id
 | 
						|
            # which will be used as a cache key for future resolutions, but
 | 
						|
            # not get persisted.
 | 
						|
 | 
						|
            with Measure(self.clock, "state.create_group_ids"):
 | 
						|
                cache = _make_state_cache_entry(new_state, state_groups_ids)
 | 
						|
 | 
						|
            self._state_cache[group_names] = cache
 | 
						|
 | 
						|
            return cache
 | 
						|
 | 
						|
    async def resolve_events_with_store(
 | 
						|
        self,
 | 
						|
        room_id: str,
 | 
						|
        room_version: str,
 | 
						|
        state_sets: Sequence[StateMap[str]],
 | 
						|
        event_map: Optional[Dict[str, EventBase]],
 | 
						|
        state_res_store: "StateResolutionStore",
 | 
						|
    ) -> StateMap[str]:
 | 
						|
        """
 | 
						|
        Args:
 | 
						|
            room_id: the room we are working in
 | 
						|
 | 
						|
            room_version: Version of the room
 | 
						|
 | 
						|
            state_sets: List of dicts of (type, state_key) -> event_id,
 | 
						|
                which are the different state groups to resolve.
 | 
						|
 | 
						|
            event_map:
 | 
						|
                a dict from event_id to event, for any events that we happen to
 | 
						|
                have in flight (eg, those currently being persisted). This will be
 | 
						|
                used as a starting point for finding the state we need; any missing
 | 
						|
                events will be requested via state_map_factory.
 | 
						|
 | 
						|
                If None, all events will be fetched via state_res_store.
 | 
						|
 | 
						|
            state_res_store: a place to fetch events from
 | 
						|
 | 
						|
        Returns:
 | 
						|
            a map from (type, state_key) to event_id.
 | 
						|
        """
 | 
						|
        try:
 | 
						|
            with Measure(self.clock, "state._resolve_events") as m:
 | 
						|
                room_version_obj = KNOWN_ROOM_VERSIONS[room_version]
 | 
						|
                if room_version_obj.state_res == StateResolutionVersions.V1:
 | 
						|
                    return await v1.resolve_events_with_store(
 | 
						|
                        room_id,
 | 
						|
                        room_version_obj,
 | 
						|
                        state_sets,
 | 
						|
                        event_map,
 | 
						|
                        state_res_store.get_events,
 | 
						|
                    )
 | 
						|
                else:
 | 
						|
                    return await v2.resolve_events_with_store(
 | 
						|
                        self.clock,
 | 
						|
                        room_id,
 | 
						|
                        room_version_obj,
 | 
						|
                        state_sets,
 | 
						|
                        event_map,
 | 
						|
                        state_res_store,
 | 
						|
                    )
 | 
						|
        finally:
 | 
						|
            self._record_state_res_metrics(room_id, m.get_resource_usage())
 | 
						|
 | 
						|
    def _record_state_res_metrics(
 | 
						|
        self, room_id: str, rusage: ContextResourceUsage
 | 
						|
    ) -> None:
 | 
						|
        room_metrics = self._state_res_metrics[room_id]
 | 
						|
        room_metrics.cpu_time += rusage.ru_utime + rusage.ru_stime
 | 
						|
        room_metrics.db_time += rusage.db_txn_duration_sec
 | 
						|
        room_metrics.db_events += rusage.evt_db_fetch_count
 | 
						|
 | 
						|
        _cpu_times.observe(rusage.ru_utime + rusage.ru_stime)
 | 
						|
        _db_times.observe(rusage.db_txn_duration_sec)
 | 
						|
 | 
						|
    def _report_metrics(self) -> None:
 | 
						|
        if not self._state_res_metrics:
 | 
						|
            # no state res has happened since the last iteration: don't bother logging.
 | 
						|
            return
 | 
						|
 | 
						|
        self._report_biggest(
 | 
						|
            lambda i: i.cpu_time,
 | 
						|
            "CPU time",
 | 
						|
            _biggest_room_by_cpu_counter,
 | 
						|
        )
 | 
						|
 | 
						|
        self._report_biggest(
 | 
						|
            lambda i: i.db_time,
 | 
						|
            "DB time",
 | 
						|
            _biggest_room_by_db_counter,
 | 
						|
        )
 | 
						|
 | 
						|
        self._state_res_metrics.clear()
 | 
						|
 | 
						|
    def _report_biggest(
 | 
						|
        self,
 | 
						|
        extract_key: Callable[[_StateResMetrics], Any],
 | 
						|
        metric_name: str,
 | 
						|
        prometheus_counter_metric: Counter,
 | 
						|
    ) -> None:
 | 
						|
        """Report metrics on the biggest rooms for state res
 | 
						|
 | 
						|
        Args:
 | 
						|
            extract_key: a callable which, given a _StateResMetrics, extracts a single
 | 
						|
                metric to sort by.
 | 
						|
            metric_name: the name of the metric we have extracted, for the log line
 | 
						|
            prometheus_counter_metric: a prometheus metric recording the sum of the
 | 
						|
                the extracted metric
 | 
						|
        """
 | 
						|
        n_to_log = 10
 | 
						|
        if not metrics_logger.isEnabledFor(logging.DEBUG):
 | 
						|
            # only need the most expensive if we don't have debug logging, which
 | 
						|
            # allows nlargest() to degrade to max()
 | 
						|
            n_to_log = 1
 | 
						|
 | 
						|
        items = self._state_res_metrics.items()
 | 
						|
 | 
						|
        # log the N biggest rooms
 | 
						|
        biggest: List[Tuple[str, _StateResMetrics]] = heapq.nlargest(
 | 
						|
            n_to_log, items, key=lambda i: extract_key(i[1])
 | 
						|
        )
 | 
						|
        metrics_logger.debug(
 | 
						|
            "%i biggest rooms for state-res by %s: %s",
 | 
						|
            len(biggest),
 | 
						|
            metric_name,
 | 
						|
            ["%s (%gs)" % (r, extract_key(m)) for (r, m) in biggest],
 | 
						|
        )
 | 
						|
 | 
						|
        # report info on the single biggest to prometheus
 | 
						|
        _, biggest_metrics = biggest[0]
 | 
						|
        prometheus_counter_metric.inc(extract_key(biggest_metrics))
 | 
						|
 | 
						|
 | 
						|
def _make_state_cache_entry(
 | 
						|
    new_state: StateMap[str], state_groups_ids: Mapping[int, StateMap[str]]
 | 
						|
) -> _StateCacheEntry:
 | 
						|
    """Given a resolved state, and a set of input state groups, pick one to base
 | 
						|
    a new state group on (if any), and return an appropriately-constructed
 | 
						|
    _StateCacheEntry.
 | 
						|
 | 
						|
    Args:
 | 
						|
        new_state: resolved state map (mapping from (type, state_key) to event_id)
 | 
						|
 | 
						|
        state_groups_ids:
 | 
						|
            map from state group id to the state in that state group (where
 | 
						|
            'state' is a map from state key to event id)
 | 
						|
 | 
						|
    Returns:
 | 
						|
        The cache entry.
 | 
						|
    """
 | 
						|
    # if the new state matches any of the input state groups, we can
 | 
						|
    # use that state group again. Otherwise we will generate a state_id
 | 
						|
    # which will be used as a cache key for future resolutions, but
 | 
						|
    # not get persisted.
 | 
						|
 | 
						|
    # first look for exact matches
 | 
						|
    new_state_event_ids = set(new_state.values())
 | 
						|
    for sg, state in state_groups_ids.items():
 | 
						|
        if len(new_state_event_ids) != len(state):
 | 
						|
            continue
 | 
						|
 | 
						|
        old_state_event_ids = set(state.values())
 | 
						|
        if new_state_event_ids == old_state_event_ids:
 | 
						|
            # got an exact match.
 | 
						|
            return _StateCacheEntry(state=None, state_group=sg)
 | 
						|
 | 
						|
    # TODO: We want to create a state group for this set of events, to
 | 
						|
    # increase cache hits, but we need to make sure that it doesn't
 | 
						|
    # end up as a prev_group without being added to the database
 | 
						|
 | 
						|
    # failing that, look for the closest match.
 | 
						|
    prev_group = None
 | 
						|
    delta_ids: Optional[StateMap[str]] = None
 | 
						|
 | 
						|
    for old_group, old_state in state_groups_ids.items():
 | 
						|
        if old_state.keys() - new_state.keys():
 | 
						|
            # Currently we don't support deltas that remove keys from the state
 | 
						|
            # map, so we have to ignore this group as a candidate to base the
 | 
						|
            # new group on.
 | 
						|
            continue
 | 
						|
 | 
						|
        n_delta_ids = {k: v for k, v in new_state.items() if old_state.get(k) != v}
 | 
						|
        if not delta_ids or len(n_delta_ids) < len(delta_ids):
 | 
						|
            prev_group = old_group
 | 
						|
            delta_ids = n_delta_ids
 | 
						|
 | 
						|
    if prev_group is not None:
 | 
						|
        # If we have a prev group and deltas then we can drop the new state from
 | 
						|
        # the cache (to reduce memory usage).
 | 
						|
        return _StateCacheEntry(
 | 
						|
            state=None, state_group=None, prev_group=prev_group, delta_ids=delta_ids
 | 
						|
        )
 | 
						|
    else:
 | 
						|
        return _StateCacheEntry(state=new_state, state_group=None)
 | 
						|
 | 
						|
 | 
						|
@attr.s(slots=True, auto_attribs=True)
 | 
						|
class StateResolutionStore:
 | 
						|
    """Interface that allows state resolution algorithms to access the database
 | 
						|
    in well defined way.
 | 
						|
    """
 | 
						|
 | 
						|
    store: "DataStore"
 | 
						|
 | 
						|
    def get_events(
 | 
						|
        self, event_ids: Collection[str], allow_rejected: bool = False
 | 
						|
    ) -> Awaitable[Dict[str, EventBase]]:
 | 
						|
        """Get events from the database
 | 
						|
 | 
						|
        Args:
 | 
						|
            event_ids: The event_ids of the events to fetch
 | 
						|
            allow_rejected: If True return rejected events.
 | 
						|
 | 
						|
        Returns:
 | 
						|
            An awaitable which resolves to a dict from event_id to event.
 | 
						|
        """
 | 
						|
 | 
						|
        return self.store.get_events(
 | 
						|
            event_ids,
 | 
						|
            redact_behaviour=EventRedactBehaviour.as_is,
 | 
						|
            get_prev_content=False,
 | 
						|
            allow_rejected=allow_rejected,
 | 
						|
        )
 | 
						|
 | 
						|
    def get_auth_chain_difference(
 | 
						|
        self, room_id: str, state_sets: List[Set[str]]
 | 
						|
    ) -> Awaitable[Set[str]]:
 | 
						|
        """Given sets of state events figure out the auth chain difference (as
 | 
						|
        per state res v2 algorithm).
 | 
						|
 | 
						|
        This equivalent to fetching the full auth chain for each set of state
 | 
						|
        and returning the events that don't appear in each and every auth
 | 
						|
        chain.
 | 
						|
 | 
						|
        Returns:
 | 
						|
            An awaitable that resolves to a set of event IDs.
 | 
						|
        """
 | 
						|
 | 
						|
        return self.store.get_auth_chain_difference(room_id, state_sets)
 |