583 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			583 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			Python
		
	
	
# -*- coding: utf-8 -*-
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# Copyright 2014-2016 OpenMarket Ltd
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# Copyright 2019 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 datetime
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import logging
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from typing import TYPE_CHECKING, Dict, Hashable, Iterable, List, Optional, Tuple, cast
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from prometheus_client import Counter
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from synapse.api.errors import (
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    FederationDeniedError,
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    HttpResponseException,
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    RequestSendFailed,
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)
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from synapse.api.presence import UserPresenceState
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from synapse.events import EventBase
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from synapse.federation.units import Edu
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from synapse.handlers.presence import format_user_presence_state
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from synapse.metrics import sent_transactions_counter
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from synapse.metrics.background_process_metrics import run_as_background_process
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from synapse.types import ReadReceipt
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from synapse.util.retryutils import NotRetryingDestination, get_retry_limiter
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if TYPE_CHECKING:
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    import synapse.server
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# This is defined in the Matrix spec and enforced by the receiver.
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MAX_EDUS_PER_TRANSACTION = 100
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logger = logging.getLogger(__name__)
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sent_edus_counter = Counter(
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    "synapse_federation_client_sent_edus", "Total number of EDUs successfully sent"
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)
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sent_edus_by_type = Counter(
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    "synapse_federation_client_sent_edus_by_type",
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    "Number of sent EDUs successfully sent, by event type",
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    ["type"],
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)
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class PerDestinationQueue:
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    """
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    Manages the per-destination transmission queues.
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    Args:
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        hs
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        transaction_sender
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        destination: the server_name of the destination that we are managing
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            transmission for.
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    """
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    def __init__(
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        self,
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        hs: "synapse.server.HomeServer",
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        transaction_manager: "synapse.federation.sender.TransactionManager",
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        destination: str,
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    ):
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        self._server_name = hs.hostname
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        self._clock = hs.get_clock()
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        self._store = hs.get_datastore()
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        self._transaction_manager = transaction_manager
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        self._instance_name = hs.get_instance_name()
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        self._federation_shard_config = hs.config.worker.federation_shard_config
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        self._should_send_on_this_instance = True
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        if not self._federation_shard_config.should_handle(
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            self._instance_name, destination
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        ):
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            # We don't raise an exception here to avoid taking out any other
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            # processing. We have a guard in `attempt_new_transaction` that
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            # ensure we don't start sending stuff.
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            logger.error(
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                "Create a per destination queue for %s on wrong worker", destination,
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            )
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            self._should_send_on_this_instance = False
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        self._destination = destination
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        self.transmission_loop_running = False
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        # True whilst we are sending events that the remote homeserver missed
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        # because it was unreachable. We start in this state so we can perform
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        # catch-up at startup.
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        # New events will only be sent once this is finished, at which point
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        # _catching_up is flipped to False.
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        self._catching_up = True  # type: bool
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        # The stream_ordering of the most recent PDU that was discarded due to
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        # being in catch-up mode.
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        self._catchup_last_skipped = 0  # type: int
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        # Cache of the last successfully-transmitted stream ordering for this
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        # destination (we are the only updater so this is safe)
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        self._last_successful_stream_ordering = None  # type: Optional[int]
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        # a list of pending PDUs
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        self._pending_pdus = []  # type: List[EventBase]
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        # XXX this is never actually used: see
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        # https://github.com/matrix-org/synapse/issues/7549
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        self._pending_edus = []  # type: List[Edu]
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        # Pending EDUs by their "key". Keyed EDUs are EDUs that get clobbered
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        # based on their key (e.g. typing events by room_id)
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        # Map of (edu_type, key) -> Edu
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        self._pending_edus_keyed = {}  # type: Dict[Tuple[str, Hashable], Edu]
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        # Map of user_id -> UserPresenceState of pending presence to be sent to this
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        # destination
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        self._pending_presence = {}  # type: Dict[str, UserPresenceState]
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        # room_id -> receipt_type -> user_id -> receipt_dict
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        self._pending_rrs = {}  # type: Dict[str, Dict[str, Dict[str, dict]]]
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        self._rrs_pending_flush = False
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        # stream_id of last successfully sent to-device message.
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        # NB: may be a long or an int.
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        self._last_device_stream_id = 0
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        # stream_id of last successfully sent device list update.
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        self._last_device_list_stream_id = 0
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    def __str__(self) -> str:
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        return "PerDestinationQueue[%s]" % self._destination
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    def pending_pdu_count(self) -> int:
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        return len(self._pending_pdus)
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    def pending_edu_count(self) -> int:
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        return (
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            len(self._pending_edus)
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            + len(self._pending_presence)
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            + len(self._pending_edus_keyed)
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        )
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    def send_pdu(self, pdu: EventBase) -> None:
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        """Add a PDU to the queue, and start the transmission loop if necessary
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        Args:
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            pdu: pdu to send
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        """
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        if not self._catching_up or self._last_successful_stream_ordering is None:
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            # only enqueue the PDU if we are not catching up (False) or do not
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            # yet know if we have anything to catch up (None)
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            self._pending_pdus.append(pdu)
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        else:
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            assert pdu.internal_metadata.stream_ordering
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            self._catchup_last_skipped = pdu.internal_metadata.stream_ordering
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        self.attempt_new_transaction()
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    def send_presence(self, states: Iterable[UserPresenceState]) -> None:
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        """Add presence updates to the queue. Start the transmission loop if necessary.
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        Args:
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            states: presence to send
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        """
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        self._pending_presence.update({state.user_id: state for state in states})
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        self.attempt_new_transaction()
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    def queue_read_receipt(self, receipt: ReadReceipt) -> None:
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        """Add a RR to the list to be sent. Doesn't start the transmission loop yet
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        (see flush_read_receipts_for_room)
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        Args:
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            receipt: receipt to be queued
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        """
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        self._pending_rrs.setdefault(receipt.room_id, {}).setdefault(
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            receipt.receipt_type, {}
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        )[receipt.user_id] = {"event_ids": receipt.event_ids, "data": receipt.data}
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    def flush_read_receipts_for_room(self, room_id: str) -> None:
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        # if we don't have any read-receipts for this room, it may be that we've already
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        # sent them out, so we don't need to flush.
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        if room_id not in self._pending_rrs:
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            return
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        self._rrs_pending_flush = True
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        self.attempt_new_transaction()
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    def send_keyed_edu(self, edu: Edu, key: Hashable) -> None:
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        self._pending_edus_keyed[(edu.edu_type, key)] = edu
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        self.attempt_new_transaction()
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    def send_edu(self, edu) -> None:
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        self._pending_edus.append(edu)
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        self.attempt_new_transaction()
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    def attempt_new_transaction(self) -> None:
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        """Try to start a new transaction to this destination
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        If there is already a transaction in progress to this destination,
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        returns immediately. Otherwise kicks off the process of sending a
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        transaction in the background.
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        """
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        if self.transmission_loop_running:
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            # XXX: this can get stuck on by a never-ending
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            # request at which point pending_pdus just keeps growing.
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            # we need application-layer timeouts of some flavour of these
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            # requests
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            logger.debug("TX [%s] Transaction already in progress", self._destination)
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            return
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        if not self._should_send_on_this_instance:
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            # We don't raise an exception here to avoid taking out any other
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            # processing.
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            logger.error(
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                "Trying to start a transaction to %s on wrong worker", self._destination
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            )
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            return
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        logger.debug("TX [%s] Starting transaction loop", self._destination)
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        run_as_background_process(
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            "federation_transaction_transmission_loop",
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            self._transaction_transmission_loop,
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        )
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    async def _transaction_transmission_loop(self) -> None:
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        pending_pdus = []  # type: List[EventBase]
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        try:
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            self.transmission_loop_running = True
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            # This will throw if we wouldn't retry. We do this here so we fail
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            # quickly, but we will later check this again in the http client,
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            # hence why we throw the result away.
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            await get_retry_limiter(self._destination, self._clock, self._store)
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            if self._catching_up:
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                # we potentially need to catch-up first
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                await self._catch_up_transmission_loop()
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                if self._catching_up:
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                    # not caught up yet
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                    return
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            pending_pdus = []
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            while True:
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                # We have to keep 2 free slots for presence and rr_edus
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                limit = MAX_EDUS_PER_TRANSACTION - 2
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                device_update_edus, dev_list_id = await self._get_device_update_edus(
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                    limit
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                )
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                limit -= len(device_update_edus)
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                (
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                    to_device_edus,
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                    device_stream_id,
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                ) = await self._get_to_device_message_edus(limit)
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                pending_edus = device_update_edus + to_device_edus
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                # BEGIN CRITICAL SECTION
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                #
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                # In order to avoid a race condition, we need to make sure that
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                # the following code (from popping the queues up to the point
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                # where we decide if we actually have any pending messages) is
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                # atomic - otherwise new PDUs or EDUs might arrive in the
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                # meantime, but not get sent because we hold the
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                # transmission_loop_running flag.
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                pending_pdus = self._pending_pdus
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                # We can only include at most 50 PDUs per transactions
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                pending_pdus, self._pending_pdus = pending_pdus[:50], pending_pdus[50:]
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                pending_edus.extend(self._get_rr_edus(force_flush=False))
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                pending_presence = self._pending_presence
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                self._pending_presence = {}
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                if pending_presence:
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                    pending_edus.append(
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                        Edu(
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                            origin=self._server_name,
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                            destination=self._destination,
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                            edu_type="m.presence",
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                            content={
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                                "push": [
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                                    format_user_presence_state(
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                                        presence, self._clock.time_msec()
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                                    )
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                                    for presence in pending_presence.values()
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                                ]
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                            },
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                        )
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                    )
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                pending_edus.extend(
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                    self._pop_pending_edus(MAX_EDUS_PER_TRANSACTION - len(pending_edus))
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                )
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                while (
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                    len(pending_edus) < MAX_EDUS_PER_TRANSACTION
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                    and self._pending_edus_keyed
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                ):
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                    _, val = self._pending_edus_keyed.popitem()
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                    pending_edus.append(val)
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                if pending_pdus:
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                    logger.debug(
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                        "TX [%s] len(pending_pdus_by_dest[dest]) = %d",
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                        self._destination,
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                        len(pending_pdus),
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                    )
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                if not pending_pdus and not pending_edus:
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                    logger.debug("TX [%s] Nothing to send", self._destination)
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                    self._last_device_stream_id = device_stream_id
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                    return
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                # if we've decided to send a transaction anyway, and we have room, we
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                # may as well send any pending RRs
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                if len(pending_edus) < MAX_EDUS_PER_TRANSACTION:
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                    pending_edus.extend(self._get_rr_edus(force_flush=True))
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                # END CRITICAL SECTION
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                success = await self._transaction_manager.send_new_transaction(
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                    self._destination, pending_pdus, pending_edus
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                )
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                if success:
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                    sent_transactions_counter.inc()
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                    sent_edus_counter.inc(len(pending_edus))
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                    for edu in pending_edus:
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                        sent_edus_by_type.labels(edu.edu_type).inc()
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                    # Remove the acknowledged device messages from the database
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                    # Only bother if we actually sent some device messages
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                    if to_device_edus:
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                        await self._store.delete_device_msgs_for_remote(
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                            self._destination, device_stream_id
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                        )
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                    # also mark the device updates as sent
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                    if device_update_edus:
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                        logger.info(
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                            "Marking as sent %r %r", self._destination, dev_list_id
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                        )
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                        await self._store.mark_as_sent_devices_by_remote(
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                            self._destination, dev_list_id
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                        )
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                    self._last_device_stream_id = device_stream_id
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                    self._last_device_list_stream_id = dev_list_id
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                    if pending_pdus:
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                        # we sent some PDUs and it was successful, so update our
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                        # last_successful_stream_ordering in the destinations table.
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                        final_pdu = pending_pdus[-1]
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                        last_successful_stream_ordering = (
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                            final_pdu.internal_metadata.stream_ordering
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                        )
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                        assert last_successful_stream_ordering
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                        await self._store.set_destination_last_successful_stream_ordering(
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                            self._destination, last_successful_stream_ordering
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                        )
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                else:
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                    break
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						||
        except NotRetryingDestination as e:
 | 
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            logger.debug(
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                "TX [%s] not ready for retry yet (next retry at %s) - "
 | 
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                "dropping transaction for now",
 | 
						||
                self._destination,
 | 
						||
                datetime.datetime.fromtimestamp(
 | 
						||
                    (e.retry_last_ts + e.retry_interval) / 1000.0
 | 
						||
                ),
 | 
						||
            )
 | 
						||
 | 
						||
            if e.retry_interval > 60 * 60 * 1000:
 | 
						||
                # we won't retry for another hour!
 | 
						||
                # (this suggests a significant outage)
 | 
						||
                # We drop pending EDUs because otherwise they will
 | 
						||
                # rack up indefinitely.
 | 
						||
                # (Dropping PDUs is already performed by `_start_catching_up`.)
 | 
						||
                # Note that:
 | 
						||
                # - the EDUs that are being dropped here are those that we can
 | 
						||
                #   afford to drop (specifically, only typing notifications,
 | 
						||
                #   read receipts and presence updates are being dropped here)
 | 
						||
                # - Other EDUs such as to_device messages are queued with a
 | 
						||
                #   different mechanism
 | 
						||
                # - this is all volatile state that would be lost if the
 | 
						||
                #   federation sender restarted anyway
 | 
						||
 | 
						||
                # dropping read receipts is a bit sad but should be solved
 | 
						||
                # through another mechanism, because this is all volatile!
 | 
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                self._pending_edus = []
 | 
						||
                self._pending_edus_keyed = {}
 | 
						||
                self._pending_presence = {}
 | 
						||
                self._pending_rrs = {}
 | 
						||
 | 
						||
            self._start_catching_up()
 | 
						||
        except FederationDeniedError as e:
 | 
						||
            logger.info(e)
 | 
						||
        except HttpResponseException as e:
 | 
						||
            logger.warning(
 | 
						||
                "TX [%s] Received %d response to transaction: %s",
 | 
						||
                self._destination,
 | 
						||
                e.code,
 | 
						||
                e,
 | 
						||
            )
 | 
						||
 | 
						||
            self._start_catching_up()
 | 
						||
        except RequestSendFailed as e:
 | 
						||
            logger.warning(
 | 
						||
                "TX [%s] Failed to send transaction: %s", self._destination, e
 | 
						||
            )
 | 
						||
 | 
						||
            for p in pending_pdus:
 | 
						||
                logger.info(
 | 
						||
                    "Failed to send event %s to %s", p.event_id, self._destination
 | 
						||
                )
 | 
						||
 | 
						||
            self._start_catching_up()
 | 
						||
        except Exception:
 | 
						||
            logger.exception("TX [%s] Failed to send transaction", self._destination)
 | 
						||
            for p in pending_pdus:
 | 
						||
                logger.info(
 | 
						||
                    "Failed to send event %s to %s", p.event_id, self._destination
 | 
						||
                )
 | 
						||
 | 
						||
            self._start_catching_up()
 | 
						||
        finally:
 | 
						||
            # We want to be *very* sure we clear this after we stop processing
 | 
						||
            self.transmission_loop_running = False
 | 
						||
 | 
						||
    async def _catch_up_transmission_loop(self) -> None:
 | 
						||
        first_catch_up_check = self._last_successful_stream_ordering is None
 | 
						||
 | 
						||
        if first_catch_up_check:
 | 
						||
            # first catchup so get last_successful_stream_ordering from database
 | 
						||
            self._last_successful_stream_ordering = await self._store.get_destination_last_successful_stream_ordering(
 | 
						||
                self._destination
 | 
						||
            )
 | 
						||
 | 
						||
        if self._last_successful_stream_ordering is None:
 | 
						||
            # if it's still None, then this means we don't have the information
 | 
						||
            # in our database  we haven't successfully sent a PDU to this server
 | 
						||
            # (at least since the introduction of the feature tracking
 | 
						||
            # last_successful_stream_ordering).
 | 
						||
            # Sadly, this means we can't do anything here as we don't know what
 | 
						||
            # needs catching up — so catching up is futile; let's stop.
 | 
						||
            self._catching_up = False
 | 
						||
            return
 | 
						||
 | 
						||
        # get at most 50 catchup room/PDUs
 | 
						||
        while True:
 | 
						||
            event_ids = await self._store.get_catch_up_room_event_ids(
 | 
						||
                self._destination, self._last_successful_stream_ordering,
 | 
						||
            )
 | 
						||
 | 
						||
            if not event_ids:
 | 
						||
                # No more events to catch up on, but we can't ignore the chance
 | 
						||
                # of a race condition, so we check that no new events have been
 | 
						||
                # skipped due to us being in catch-up mode
 | 
						||
 | 
						||
                if self._catchup_last_skipped > self._last_successful_stream_ordering:
 | 
						||
                    # another event has been skipped because we were in catch-up mode
 | 
						||
                    continue
 | 
						||
 | 
						||
                # we are done catching up!
 | 
						||
                self._catching_up = False
 | 
						||
                break
 | 
						||
 | 
						||
            if first_catch_up_check:
 | 
						||
                # as this is our check for needing catch-up, we may have PDUs in
 | 
						||
                # the queue from before we *knew* we had to do catch-up, so
 | 
						||
                # clear those out now.
 | 
						||
                self._start_catching_up()
 | 
						||
 | 
						||
            # fetch the relevant events from the event store
 | 
						||
            # - redacted behaviour of REDACT is fine, since we only send metadata
 | 
						||
            #   of redacted events to the destination.
 | 
						||
            # - don't need to worry about rejected events as we do not actively
 | 
						||
            #   forward received events over federation.
 | 
						||
            catchup_pdus = await self._store.get_events_as_list(event_ids)
 | 
						||
            if not catchup_pdus:
 | 
						||
                raise AssertionError(
 | 
						||
                    "No events retrieved when we asked for %r. "
 | 
						||
                    "This should not happen." % event_ids
 | 
						||
                )
 | 
						||
 | 
						||
            if logger.isEnabledFor(logging.INFO):
 | 
						||
                rooms = [p.room_id for p in catchup_pdus]
 | 
						||
                logger.info("Catching up rooms to %s: %r", self._destination, rooms)
 | 
						||
 | 
						||
            success = await self._transaction_manager.send_new_transaction(
 | 
						||
                self._destination, catchup_pdus, []
 | 
						||
            )
 | 
						||
 | 
						||
            if not success:
 | 
						||
                return
 | 
						||
 | 
						||
            sent_transactions_counter.inc()
 | 
						||
            final_pdu = catchup_pdus[-1]
 | 
						||
            self._last_successful_stream_ordering = cast(
 | 
						||
                int, final_pdu.internal_metadata.stream_ordering
 | 
						||
            )
 | 
						||
            await self._store.set_destination_last_successful_stream_ordering(
 | 
						||
                self._destination, self._last_successful_stream_ordering
 | 
						||
            )
 | 
						||
 | 
						||
    def _get_rr_edus(self, force_flush: bool) -> Iterable[Edu]:
 | 
						||
        if not self._pending_rrs:
 | 
						||
            return
 | 
						||
        if not force_flush and not self._rrs_pending_flush:
 | 
						||
            # not yet time for this lot
 | 
						||
            return
 | 
						||
 | 
						||
        edu = Edu(
 | 
						||
            origin=self._server_name,
 | 
						||
            destination=self._destination,
 | 
						||
            edu_type="m.receipt",
 | 
						||
            content=self._pending_rrs,
 | 
						||
        )
 | 
						||
        self._pending_rrs = {}
 | 
						||
        self._rrs_pending_flush = False
 | 
						||
        yield edu
 | 
						||
 | 
						||
    def _pop_pending_edus(self, limit: int) -> List[Edu]:
 | 
						||
        pending_edus = self._pending_edus
 | 
						||
        pending_edus, self._pending_edus = pending_edus[:limit], pending_edus[limit:]
 | 
						||
        return pending_edus
 | 
						||
 | 
						||
    async def _get_device_update_edus(self, limit: int) -> Tuple[List[Edu], int]:
 | 
						||
        last_device_list = self._last_device_list_stream_id
 | 
						||
 | 
						||
        # Retrieve list of new device updates to send to the destination
 | 
						||
        now_stream_id, results = await self._store.get_device_updates_by_remote(
 | 
						||
            self._destination, last_device_list, limit=limit
 | 
						||
        )
 | 
						||
        edus = [
 | 
						||
            Edu(
 | 
						||
                origin=self._server_name,
 | 
						||
                destination=self._destination,
 | 
						||
                edu_type=edu_type,
 | 
						||
                content=content,
 | 
						||
            )
 | 
						||
            for (edu_type, content) in results
 | 
						||
        ]
 | 
						||
 | 
						||
        assert len(edus) <= limit, "get_device_updates_by_remote returned too many EDUs"
 | 
						||
 | 
						||
        return (edus, now_stream_id)
 | 
						||
 | 
						||
    async def _get_to_device_message_edus(self, limit: int) -> Tuple[List[Edu], int]:
 | 
						||
        last_device_stream_id = self._last_device_stream_id
 | 
						||
        to_device_stream_id = self._store.get_to_device_stream_token()
 | 
						||
        contents, stream_id = await self._store.get_new_device_msgs_for_remote(
 | 
						||
            self._destination, last_device_stream_id, to_device_stream_id, limit
 | 
						||
        )
 | 
						||
        edus = [
 | 
						||
            Edu(
 | 
						||
                origin=self._server_name,
 | 
						||
                destination=self._destination,
 | 
						||
                edu_type="m.direct_to_device",
 | 
						||
                content=content,
 | 
						||
            )
 | 
						||
            for content in contents
 | 
						||
        ]
 | 
						||
 | 
						||
        return (edus, stream_id)
 | 
						||
 | 
						||
    def _start_catching_up(self) -> None:
 | 
						||
        """
 | 
						||
        Marks this destination as being in catch-up mode.
 | 
						||
 | 
						||
        This throws away the PDU queue.
 | 
						||
        """
 | 
						||
        self._catching_up = True
 | 
						||
        self._pending_pdus = []
 |