551 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			551 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			Python
		
	
	
# Copyright 2015 OpenMarket Ltd
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# Copyright 2017 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 logging
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from typing import (
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    TYPE_CHECKING,
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    Any,
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    Collection,
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    Dict,
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    List,
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    Mapping,
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    Optional,
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    Sequence,
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    Tuple,
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    Union,
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)
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from prometheus_client import Counter
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from synapse.api.constants import (
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    MAIN_TIMELINE,
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    EventContentFields,
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    EventTypes,
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    Membership,
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    RelationTypes,
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)
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from synapse.api.room_versions import PushRuleRoomFlag
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from synapse.event_auth import auth_types_for_event, get_user_power_level
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from synapse.events import EventBase, relation_from_event
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from synapse.events.snapshot import EventContext
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from synapse.state import POWER_KEY
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from synapse.storage.databases.main.roommember import EventIdMembership
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from synapse.synapse_rust.push import FilteredPushRules, PushRuleEvaluator
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from synapse.types import JsonValue
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from synapse.types.state import StateFilter
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from synapse.util.caches import register_cache
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from synapse.util.metrics import measure_func
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from synapse.visibility import filter_event_for_clients_with_state
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if TYPE_CHECKING:
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    from synapse.server import HomeServer
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logger = logging.getLogger(__name__)
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push_rules_invalidation_counter = Counter(
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    "synapse_push_bulk_push_rule_evaluator_push_rules_invalidation_counter", ""
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)
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push_rules_state_size_counter = Counter(
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    "synapse_push_bulk_push_rule_evaluator_push_rules_state_size_counter", ""
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)
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STATE_EVENT_TYPES_TO_MARK_UNREAD = {
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    EventTypes.Topic,
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    EventTypes.Name,
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    EventTypes.RoomAvatar,
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    EventTypes.Tombstone,
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}
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SENTINEL = object()
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def _should_count_as_unread(event: EventBase, context: EventContext) -> bool:
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    # Exclude rejected and soft-failed events.
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    if context.rejected or event.internal_metadata.is_soft_failed():
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        return False
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    # Exclude notices.
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    if (
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        not event.is_state()
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        and event.type == EventTypes.Message
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        and event.content.get("msgtype") == "m.notice"
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    ):
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        return False
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    # Exclude edits.
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    relates_to = relation_from_event(event)
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    if relates_to and relates_to.rel_type == RelationTypes.REPLACE:
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        return False
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    # Mark events that have a non-empty string body as unread.
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    body = event.content.get("body")
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    if isinstance(body, str) and body:
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        return True
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    # Mark some state events as unread.
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    if event.is_state() and event.type in STATE_EVENT_TYPES_TO_MARK_UNREAD:
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        return True
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    # Mark encrypted events as unread.
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    if not event.is_state() and event.type == EventTypes.Encrypted:
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        return True
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    return False
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class BulkPushRuleEvaluator:
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    """Calculates the outcome of push rules for an event for all users in the
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    room at once.
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    """
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    def __init__(self, hs: "HomeServer"):
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        self.hs = hs
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        self.store = hs.get_datastores().main
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        self.clock = hs.get_clock()
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        self._event_auth_handler = hs.get_event_auth_handler()
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        self.should_calculate_push_rules = self.hs.config.push.enable_push
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        self._related_event_match_enabled = self.hs.config.experimental.msc3664_enabled
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        self.room_push_rule_cache_metrics = register_cache(
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            "cache",
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            "room_push_rule_cache",
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            cache=[],  # Meaningless size, as this isn't a cache that stores values,
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            resizable=False,
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        )
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    async def _get_rules_for_event(
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        self,
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        event: EventBase,
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    ) -> Mapping[str, FilteredPushRules]:
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        """Get the push rules for all users who may need to be notified about
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        the event.
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        Note: this does not check if the user is allowed to see the event.
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        Returns:
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            Mapping of user ID to their push rules.
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        """
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        # If this is a membership event, only calculate push rules for the target.
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        # While it's possible for users to configure push rules to respond to such an
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        # event, in practise nobody does this. At the cost of violating the spec a
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        # little, we can skip fetching a huge number of push rules in large rooms.
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        # This helps make joins and leaves faster.
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        if event.type == EventTypes.Member:
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            local_users: Sequence[str] = []
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            # We never notify a user about their own actions. This is enforced in
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            # `_action_for_event_by_user` in the loop over `rules_by_user`, but we
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            # do the same check here to avoid unnecessary DB queries.
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            if event.sender != event.state_key and self.hs.is_mine_id(event.state_key):
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                # Check the target is in the room, to avoid notifying them of
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                # e.g. a pre-emptive ban.
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                target_already_in_room = await self.store.check_local_user_in_room(
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                    event.state_key, event.room_id
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                )
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                if target_already_in_room:
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                    local_users = [event.state_key]
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        else:
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            # We get the users who may need to be notified by first fetching the
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            # local users currently in the room, finding those that have push rules,
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            # and *then* checking which users are actually allowed to see the event.
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            #
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            # The alternative is to first fetch all users that were joined at the
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            # event, but that requires fetching the full state at the event, which
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            # may be expensive for large rooms with few local users.
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            local_users = await self.store.get_local_users_in_room(event.room_id)
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        # Filter out appservice users.
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        local_users = [
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            u
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            for u in local_users
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            if not self.store.get_if_app_services_interested_in_user(u)
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        ]
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        # if this event is an invite event, we may need to run rules for the user
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        # who's been invited, otherwise they won't get told they've been invited
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        if event.type == EventTypes.Member and event.membership == Membership.INVITE:
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            invited = event.state_key
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            if invited and self.hs.is_mine_id(invited) and invited not in local_users:
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                local_users.append(invited)
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        if not local_users:
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            return {}
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        rules_by_user = await self.store.bulk_get_push_rules(local_users)
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        logger.debug("Users in room: %s", local_users)
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        if logger.isEnabledFor(logging.DEBUG):
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            logger.debug(
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                "Returning push rules for %r %r",
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                event.room_id,
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                list(rules_by_user.keys()),
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            )
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        return rules_by_user
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    async def _get_power_levels_and_sender_level(
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        self,
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        event: EventBase,
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        context: EventContext,
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        event_id_to_event: Mapping[str, EventBase],
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    ) -> Tuple[dict, Optional[int]]:
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        """
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        Given an event and an event context, get the power level event relevant to the event
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        and the power level of the sender of the event.
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        Args:
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            event: event to check
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            context: context of event to check
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            event_id_to_event: a mapping of event_id to event for a set of events being
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            batch persisted. This is needed as the sought-after power level event may
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            be in this batch rather than the DB
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        """
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        # There are no power levels and sender levels possible to get from outlier
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        if event.internal_metadata.is_outlier():
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            return {}, None
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        event_types = auth_types_for_event(event.room_version, event)
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        prev_state_ids = await context.get_prev_state_ids(
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            StateFilter.from_types(event_types)
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        )
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        pl_event_id = prev_state_ids.get(POWER_KEY)
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        # fastpath: if there's a power level event, that's all we need, and
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        # not having a power level event is an extreme edge case
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        if pl_event_id:
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            # Get the power level event from the batch, or fall back to the database.
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            pl_event = event_id_to_event.get(pl_event_id)
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            if pl_event:
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                auth_events = {POWER_KEY: pl_event}
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            else:
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                auth_events = {POWER_KEY: await self.store.get_event(pl_event_id)}
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        else:
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            auth_events_ids = self._event_auth_handler.compute_auth_events(
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                event, prev_state_ids, for_verification=False
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            )
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            auth_events_dict = await self.store.get_events(auth_events_ids)
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            # Some needed auth events might be in the batch, combine them with those
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            # fetched from the database.
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            for auth_event_id in auth_events_ids:
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                auth_event = event_id_to_event.get(auth_event_id)
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                if auth_event:
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                    auth_events_dict[auth_event_id] = auth_event
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            auth_events = {(e.type, e.state_key): e for e in auth_events_dict.values()}
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        sender_level = get_user_power_level(event.sender, auth_events)
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        pl_event = auth_events.get(POWER_KEY)
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        return pl_event.content if pl_event else {}, sender_level
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    async def _related_events(
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        self, event: EventBase
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    ) -> Dict[str, Dict[str, JsonValue]]:
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        """Fetches the related events for 'event'. Sets the im.vector.is_falling_back key if the event is from a fallback relation
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        Returns:
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            Mapping of relation type to flattened events.
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        """
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        related_events: Dict[str, Dict[str, JsonValue]] = {}
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        if self._related_event_match_enabled:
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            related_event_id = event.content.get("m.relates_to", {}).get("event_id")
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            relation_type = event.content.get("m.relates_to", {}).get("rel_type")
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            if related_event_id is not None and relation_type is not None:
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                related_event = await self.store.get_event(
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                    related_event_id, allow_none=True
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                )
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                if related_event is not None:
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                    related_events[relation_type] = _flatten_dict(related_event)
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            reply_event_id = (
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                event.content.get("m.relates_to", {})
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                .get("m.in_reply_to", {})
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                .get("event_id")
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            )
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            # convert replies to pseudo relations
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            if reply_event_id is not None:
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                related_event = await self.store.get_event(
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                    reply_event_id, allow_none=True
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                )
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                if related_event is not None:
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                    related_events["m.in_reply_to"] = _flatten_dict(related_event)
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                    # indicate that this is from a fallback relation.
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                    if relation_type == "m.thread" and event.content.get(
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                        "m.relates_to", {}
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                    ).get("is_falling_back", False):
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                        related_events["m.in_reply_to"][
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                            "im.vector.is_falling_back"
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                        ] = ""
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        return related_events
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    async def action_for_events_by_user(
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        self, events_and_context: List[Tuple[EventBase, EventContext]]
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    ) -> None:
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        """Given a list of events and their associated contexts, evaluate the push rules
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        for each event, check if the message should increment the unread count, and
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        insert the results into the event_push_actions_staging table.
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        """
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        if not self.should_calculate_push_rules:
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            return
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        # For batched events the power level events may not have been persisted yet,
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        # so we pass in the batched events. Thus if the event cannot be found in the
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        # database we can check in the batch.
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        event_id_to_event = {e.event_id: e for e, _ in events_and_context}
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        for event, context in events_and_context:
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            await self._action_for_event_by_user(event, context, event_id_to_event)
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    @measure_func("action_for_event_by_user")
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    async def _action_for_event_by_user(
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        self,
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        event: EventBase,
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        context: EventContext,
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        event_id_to_event: Mapping[str, EventBase],
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    ) -> None:
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        if (
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            not event.internal_metadata.is_notifiable()
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            or event.room_id in self.hs.config.server.rooms_to_exclude_from_sync
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        ):
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            # Push rules for events that aren't notifiable can't be processed by this and
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            # we want to skip push notification actions for historical messages
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            # because we don't want to notify people about old history back in time.
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            # The historical messages also do not have the proper `context.current_state_ids`
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            # and `state_groups` because they have `prev_events` that aren't persisted yet
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            # (historical messages persisted in reverse-chronological order).
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            return
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        # Disable counting as unread unless the experimental configuration is
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        # enabled, as it can cause additional (unwanted) rows to be added to the
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        # event_push_actions table.
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        count_as_unread = False
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        if self.hs.config.experimental.msc2654_enabled:
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            count_as_unread = _should_count_as_unread(event, context)
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        rules_by_user = await self._get_rules_for_event(event)
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        actions_by_user: Dict[str, Collection[Union[Mapping, str]]] = {}
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        room_member_count = await self.store.get_number_joined_users_in_room(
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            event.room_id
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        )
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        (
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            power_levels,
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            sender_power_level,
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        ) = await self._get_power_levels_and_sender_level(
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            event, context, event_id_to_event
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        )
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        # Find the event's thread ID.
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        relation = relation_from_event(event)
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        # If the event does not have a relation, then it cannot have a thread ID.
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        thread_id = MAIN_TIMELINE
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        if relation:
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            # Recursively attempt to find the thread this event relates to.
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            if relation.rel_type == RelationTypes.THREAD:
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                thread_id = relation.parent_id
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            else:
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                # Since the event has not yet been persisted we check whether
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                # the parent is part of a thread.
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                thread_id = await self.store.get_thread_id(relation.parent_id)
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        related_events = await self._related_events(event)
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        # It's possible that old room versions have non-integer power levels (floats or
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        # strings; even the occasional `null`). For old rooms, we interpret these as if
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        # they were integers. Do this here for the `@room` power level threshold.
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        # Note that this is done automatically for the sender's power level by
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        # _get_power_levels_and_sender_level in its call to get_user_power_level
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        # (even for room V10.)
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        notification_levels = power_levels.get("notifications", {})
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        if not event.room_version.enforce_int_power_levels:
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            keys = list(notification_levels.keys())
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            for key in keys:
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                level = notification_levels.get(key, SENTINEL)
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                if level is not SENTINEL and type(level) is not int:  # noqa: E721
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                    try:
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                        notification_levels[key] = int(level)
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                    except (TypeError, ValueError):
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                        del notification_levels[key]
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        # Pull out any user and room mentions.
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        has_mentions = EventContentFields.MENTIONS in event.content
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        evaluator = PushRuleEvaluator(
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            _flatten_dict(event),
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            has_mentions,
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            room_member_count,
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            sender_power_level,
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            notification_levels,
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            related_events,
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            self._related_event_match_enabled,
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            event.room_version.msc3931_push_features,
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            self.hs.config.experimental.msc1767_enabled,  # MSC3931 flag
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        )
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        users = rules_by_user.keys()
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        profiles = await self.store.get_subset_users_in_room_with_profiles(
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            event.room_id, users
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        )
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        for uid, rules in rules_by_user.items():
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            if event.sender == uid:
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                continue
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            display_name = None
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            profile = profiles.get(uid)
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            if profile:
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                display_name = profile.display_name
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 | 
						|
            if not display_name:
 | 
						|
                # Handle the case where we are pushing a membership event to
 | 
						|
                # that user, as they might not be already joined.
 | 
						|
                if event.type == EventTypes.Member and event.state_key == uid:
 | 
						|
                    display_name = event.content.get("displayname", None)
 | 
						|
                    if not isinstance(display_name, str):
 | 
						|
                        display_name = None
 | 
						|
 | 
						|
            if count_as_unread:
 | 
						|
                # Add an element for the current user if the event needs to be marked as
 | 
						|
                # unread, so that add_push_actions_to_staging iterates over it.
 | 
						|
                # If the event shouldn't be marked as unread but should notify the
 | 
						|
                # current user, it'll be added to the dict later.
 | 
						|
                actions_by_user[uid] = []
 | 
						|
 | 
						|
            actions = evaluator.run(rules, uid, display_name)
 | 
						|
            if "notify" in actions:
 | 
						|
                # Push rules say we should notify the user of this event
 | 
						|
                actions_by_user[uid] = actions
 | 
						|
 | 
						|
        # If there aren't any actions then we can skip the rest of the
 | 
						|
        # processing.
 | 
						|
        if not actions_by_user:
 | 
						|
            return
 | 
						|
 | 
						|
        # This is a check for the case where user joins a room without being
 | 
						|
        # allowed to see history, and then the server receives a delayed event
 | 
						|
        # from before the user joined, which they should not be pushed for
 | 
						|
        #
 | 
						|
        # We do this *after* calculating the push actions as a) its unlikely
 | 
						|
        # that we'll filter anyone out and b) for large rooms its likely that
 | 
						|
        # most users will have push disabled and so the set of users to check is
 | 
						|
        # much smaller.
 | 
						|
        uids_with_visibility = await filter_event_for_clients_with_state(
 | 
						|
            self.store, actions_by_user.keys(), event, context
 | 
						|
        )
 | 
						|
 | 
						|
        for user_id in set(actions_by_user).difference(uids_with_visibility):
 | 
						|
            actions_by_user.pop(user_id, None)
 | 
						|
 | 
						|
        # Mark in the DB staging area the push actions for users who should be
 | 
						|
        # notified for this event. (This will then get handled when we persist
 | 
						|
        # the event)
 | 
						|
        await self.store.add_push_actions_to_staging(
 | 
						|
            event.event_id,
 | 
						|
            actions_by_user,
 | 
						|
            count_as_unread,
 | 
						|
            thread_id,
 | 
						|
        )
 | 
						|
 | 
						|
 | 
						|
MemberMap = Dict[str, Optional[EventIdMembership]]
 | 
						|
Rule = Dict[str, dict]
 | 
						|
RulesByUser = Dict[str, List[Rule]]
 | 
						|
StateGroup = Union[object, int]
 | 
						|
 | 
						|
 | 
						|
def _is_simple_value(value: Any) -> bool:
 | 
						|
    return (
 | 
						|
        isinstance(value, (bool, str))
 | 
						|
        or type(value) is int  # noqa: E721
 | 
						|
        or value is None
 | 
						|
    )
 | 
						|
 | 
						|
 | 
						|
def _flatten_dict(
 | 
						|
    d: Union[EventBase, Mapping[str, Any]],
 | 
						|
    prefix: Optional[List[str]] = None,
 | 
						|
    result: Optional[Dict[str, JsonValue]] = None,
 | 
						|
) -> Dict[str, JsonValue]:
 | 
						|
    """
 | 
						|
    Given a JSON dictionary (or event) which might contain sub dictionaries,
 | 
						|
    flatten it into a single layer dictionary by combining the keys & sub-keys.
 | 
						|
 | 
						|
    String, integer, boolean, null or lists of those values are kept. All others are dropped.
 | 
						|
 | 
						|
    Transforms:
 | 
						|
 | 
						|
        {"foo": {"bar": "test"}}
 | 
						|
 | 
						|
    To:
 | 
						|
 | 
						|
        {"foo.bar": "test"}
 | 
						|
 | 
						|
    Args:
 | 
						|
        d: The event or content to continue flattening.
 | 
						|
        prefix: The key prefix (from outer dictionaries).
 | 
						|
        result: The result to mutate.
 | 
						|
 | 
						|
    Returns:
 | 
						|
        The resulting dictionary.
 | 
						|
    """
 | 
						|
    if prefix is None:
 | 
						|
        prefix = []
 | 
						|
    if result is None:
 | 
						|
        result = {}
 | 
						|
    for key, value in d.items():
 | 
						|
        # Escape periods in the key with a backslash (and backslashes with an
 | 
						|
        # extra backslash). This is since a period is used as a separator between
 | 
						|
        # nested fields.
 | 
						|
        key = key.replace("\\", "\\\\").replace(".", "\\.")
 | 
						|
 | 
						|
        if _is_simple_value(value):
 | 
						|
            result[".".join(prefix + [key])] = value
 | 
						|
        elif isinstance(value, (list, tuple)):
 | 
						|
            result[".".join(prefix + [key])] = [v for v in value if _is_simple_value(v)]
 | 
						|
        elif isinstance(value, Mapping):
 | 
						|
            # do not set `room_version` due to recursion considerations below
 | 
						|
            _flatten_dict(value, prefix=(prefix + [key]), result=result)
 | 
						|
 | 
						|
    # `room_version` should only ever be set when looking at the top level of an event
 | 
						|
    if (
 | 
						|
        isinstance(d, EventBase)
 | 
						|
        and PushRuleRoomFlag.EXTENSIBLE_EVENTS in d.room_version.msc3931_push_features
 | 
						|
    ):
 | 
						|
        # Room supports extensible events: replace `content.body` with the plain text
 | 
						|
        # representation from `m.markup`, as per MSC1767.
 | 
						|
        markup = d.get("content").get("m.markup")
 | 
						|
        if d.room_version.identifier.startswith("org.matrix.msc1767."):
 | 
						|
            markup = d.get("content").get("org.matrix.msc1767.markup")
 | 
						|
        if markup is not None and isinstance(markup, list):
 | 
						|
            text = ""
 | 
						|
            for rep in markup:
 | 
						|
                if not isinstance(rep, dict):
 | 
						|
                    # invalid markup - skip all processing
 | 
						|
                    break
 | 
						|
                if rep.get("mimetype", "text/plain") == "text/plain":
 | 
						|
                    rep_text = rep.get("body")
 | 
						|
                    if rep_text is not None and isinstance(rep_text, str):
 | 
						|
                        text = rep_text.lower()
 | 
						|
                        break
 | 
						|
            result["content.body"] = text
 | 
						|
 | 
						|
    return result
 |