lbry-sdk/lbry/extras/daemon/components.py

import math
import os
import asyncio
import logging
import binascii
import typing
from collections import deque

import base58

from aioupnp import __version__ as aioupnp_version
from aioupnp.upnp import UPnP
from aioupnp.fault import UPnPError

from lbry import utils
from lbry.dht.node import Node
from lbry.dht.peer import is_valid_public_ipv4
from lbry.dht.blob_announcer import BlobAnnouncer
from lbry.blob.blob_manager import BlobManager
from lbry.blob.disk_space_manager import DiskSpaceManager
from lbry.blob_exchange.server import BlobServer
from lbry.stream.downloader import StreamDownloader
from lbry.stream.stream_manager import StreamManager
from lbry.file.file_manager import FileManager
from lbry.extras.daemon.component import Component
from lbry.extras.daemon.exchange_rate_manager import ExchangeRateManager
from lbry.extras.daemon.storage import SQLiteStorage
from lbry.torrent.torrent_manager import TorrentManager
from lbry.wallet import WalletManager
from lbry.wallet.usage_payment import WalletServerPayer
try:
    from lbry.torrent.session import TorrentSession
except ImportError:
    TorrentSession = None

log = logging.getLogger(__name__)

# settings must be initialized before this file is imported

DATABASE_COMPONENT = "database"
BLOB_COMPONENT = "blob_manager"
WALLET_COMPONENT = "wallet"
WALLET_SERVER_PAYMENTS_COMPONENT = "wallet_server_payments"
DHT_COMPONENT = "dht"
HASH_ANNOUNCER_COMPONENT = "hash_announcer"
FILE_MANAGER_COMPONENT = "file_manager"
DISK_SPACE_COMPONENT = "disk_space"
BACKGROUND_DOWNLOADER_COMPONENT = "background_downloader"
PEER_PROTOCOL_SERVER_COMPONENT = "peer_protocol_server"
UPNP_COMPONENT = "upnp"
EXCHANGE_RATE_MANAGER_COMPONENT = "exchange_rate_manager"
LIBTORRENT_COMPONENT = "libtorrent_component"


class DatabaseComponent(Component):
    component_name = DATABASE_COMPONENT

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.storage = None

    @property
    def component(self):
        return self.storage

    @staticmethod
    def get_current_db_revision():
        return 15

    @property
    def revision_filename(self):
        return os.path.join(self.conf.data_dir, 'db_revision')

    def _write_db_revision_file(self, version_num):
        with open(self.revision_filename, mode='w') as db_revision:
            db_revision.write(str(version_num))

    async def start(self):
        # check directories exist, create them if they don't
        log.info("Loading databases")

        if not os.path.exists(self.revision_filename):
            log.info("db_revision file not found. Creating it")
            self._write_db_revision_file(self.get_current_db_revision())

        # check the db migration and run any needed migrations
        with open(self.revision_filename, "r") as revision_read_handle:
            old_revision = int(revision_read_handle.read().strip())

        if old_revision > self.get_current_db_revision():
            raise Exception('This version of lbrynet is not compatible with the database\n'
                            'Your database is revision %i, expected %i' %
                            (old_revision, self.get_current_db_revision()))
        if old_revision < self.get_current_db_revision():
            from lbry.extras.daemon.migrator import dbmigrator  # pylint: disable=import-outside-toplevel
            log.info("Upgrading your databases (revision %i to %i)", old_revision, self.get_current_db_revision())
            await asyncio.get_event_loop().run_in_executor(
                None, dbmigrator.migrate_db, self.conf, old_revision, self.get_current_db_revision()
            )
            self._write_db_revision_file(self.get_current_db_revision())
            log.info("Finished upgrading the databases.")

        self.storage = SQLiteStorage(
            self.conf, os.path.join(self.conf.data_dir, "lbrynet.sqlite")
        )
        await self.storage.open()

    async def stop(self):
        await self.storage.close()
        self.storage = None


class WalletComponent(Component):
    component_name = WALLET_COMPONENT
    depends_on = [DATABASE_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.wallet_manager = None

    @property
    def component(self):
        return self.wallet_manager

    async def get_status(self):
        if self.wallet_manager is None:
            return
        is_connected = self.wallet_manager.ledger.network.is_connected
        sessions = []
        connected = None
        if is_connected:
            addr, port = self.wallet_manager.ledger.network.client.server
            connected = f"{addr}:{port}"
            sessions.append(self.wallet_manager.ledger.network.client)

        result = {
            'connected': connected,
            'connected_features': self.wallet_manager.ledger.network.server_features,
            'servers': [
                {
                    'host': session.server[0],
                    'port': session.server[1],
                    'latency': session.connection_latency,
                    'availability': session.available,
                } for session in sessions
            ],
            'known_servers': len(self.wallet_manager.ledger.network.known_hubs),
            'available_servers': 1 if is_connected else 0
        }

        if self.wallet_manager.ledger.network.remote_height:
            local_height = self.wallet_manager.ledger.local_height_including_downloaded_height
            disk_height = len(self.wallet_manager.ledger.headers)
            remote_height = self.wallet_manager.ledger.network.remote_height
            download_height, target_height = local_height - disk_height, remote_height - disk_height
            if target_height > 0:
                progress = min(max(math.ceil(float(download_height) / float(target_height) * 100), 0), 100)
            else:
                progress = 100
            best_hash = await self.wallet_manager.get_best_blockhash()
            result.update({
                'headers_synchronization_progress': progress,
                'blocks': max(local_height, 0),
                'blocks_behind': max(remote_height - local_height, 0),
                'best_blockhash': best_hash,
            })

        return result

    async def start(self):
        log.info("Starting wallet")
        self.wallet_manager = await WalletManager.from_lbrynet_config(self.conf)
        await self.wallet_manager.start()

    async def stop(self):
        await self.wallet_manager.stop()
        self.wallet_manager = None


class WalletServerPaymentsComponent(Component):
    component_name = WALLET_SERVER_PAYMENTS_COMPONENT
    depends_on = [WALLET_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.usage_payment_service = WalletServerPayer(
            max_fee=self.conf.max_wallet_server_fee, analytics_manager=self.component_manager.analytics_manager,
        )

    @property
    def component(self) -> typing.Optional[WalletServerPayer]:
        return self.usage_payment_service

    async def start(self):
        wallet_manager = self.component_manager.get_component(WALLET_COMPONENT)
        await self.usage_payment_service.start(wallet_manager.ledger, wallet_manager.default_wallet)

    async def stop(self):
        await self.usage_payment_service.stop()

    async def get_status(self):
        return {
            'max_fee': self.usage_payment_service.max_fee,
            'running': self.usage_payment_service.running
        }


class BlobComponent(Component):
    component_name = BLOB_COMPONENT
    depends_on = [DATABASE_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.blob_manager: typing.Optional[BlobManager] = None

    @property
    def component(self) -> typing.Optional[BlobManager]:
        return self.blob_manager

    async def start(self):
        storage = self.component_manager.get_component(DATABASE_COMPONENT)
        data_store = None
        if DHT_COMPONENT not in self.component_manager.skip_components:
            dht_node: Node = self.component_manager.get_component(DHT_COMPONENT)
            if dht_node:
                data_store = dht_node.protocol.data_store
        blob_dir = os.path.join(self.conf.data_dir, 'blobfiles')
        if not os.path.isdir(blob_dir):
            os.mkdir(blob_dir)
        self.blob_manager = BlobManager(self.component_manager.loop, blob_dir, storage, self.conf, data_store)
        return await self.blob_manager.setup()

    async def stop(self):
        self.blob_manager.stop()

    async def get_status(self):
        count = 0
        if self.blob_manager:
            count = len(self.blob_manager.completed_blob_hashes)
        return {
            'finished_blobs': count,
            'connections': {} if not self.blob_manager else self.blob_manager.connection_manager.status
        }


class DHTComponent(Component):
    component_name = DHT_COMPONENT
    depends_on = [UPNP_COMPONENT, DATABASE_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.dht_node: typing.Optional[Node] = None
        self.external_udp_port = None
        self.external_peer_port = None

    @property
    def component(self) -> typing.Optional[Node]:
        return self.dht_node

    async def get_status(self):
        return {
            'node_id': None if not self.dht_node else binascii.hexlify(self.dht_node.protocol.node_id),
            'peers_in_routing_table': 0 if not self.dht_node else len(self.dht_node.protocol.routing_table.get_peers())
        }

    def get_node_id(self):
        node_id_filename = os.path.join(self.conf.data_dir, "node_id")
        if os.path.isfile(node_id_filename):
            with open(node_id_filename, "r") as node_id_file:
                return base58.b58decode(str(node_id_file.read()).strip())
        node_id = utils.generate_id()
        with open(node_id_filename, "w") as node_id_file:
            node_id_file.write(base58.b58encode(node_id).decode())
        return node_id

    async def start(self):
        log.info("start the dht")
        upnp_component = self.component_manager.get_component(UPNP_COMPONENT)
        self.external_peer_port = upnp_component.upnp_redirects.get("TCP", self.conf.tcp_port)
        self.external_udp_port = upnp_component.upnp_redirects.get("UDP", self.conf.udp_port)
        external_ip = upnp_component.external_ip
        storage = self.component_manager.get_component(DATABASE_COMPONENT)
        if not external_ip:
            external_ip, _ = await utils.get_external_ip(self.conf.lbryum_servers)
            if not external_ip:
                log.warning("failed to get external ip")

        self.dht_node = Node(
            self.component_manager.loop,
            self.component_manager.peer_manager,
            node_id=self.get_node_id(),
            internal_udp_port=self.conf.udp_port,
            udp_port=self.external_udp_port,
            external_ip=external_ip,
            peer_port=self.external_peer_port,
            rpc_timeout=self.conf.node_rpc_timeout,
            split_buckets_under_index=self.conf.split_buckets_under_index,
            storage=storage
        )
        self.dht_node.start(self.conf.network_interface, self.conf.known_dht_nodes)
        log.info("Started the dht")

    async def stop(self):
        self.dht_node.stop()


class HashAnnouncerComponent(Component):
    component_name = HASH_ANNOUNCER_COMPONENT
    depends_on = [DHT_COMPONENT, DATABASE_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.hash_announcer: typing.Optional[BlobAnnouncer] = None

    @property
    def component(self) -> typing.Optional[BlobAnnouncer]:
        return self.hash_announcer

    async def start(self):
        storage = self.component_manager.get_component(DATABASE_COMPONENT)
        dht_node = self.component_manager.get_component(DHT_COMPONENT)
        self.hash_announcer = BlobAnnouncer(self.component_manager.loop, dht_node, storage)
        self.hash_announcer.start(self.conf.concurrent_blob_announcers)
        log.info("Started blob announcer")

    async def stop(self):
        self.hash_announcer.stop()
        log.info("Stopped blob announcer")

    async def get_status(self):
        return {
            'announce_queue_size': 0 if not self.hash_announcer else len(self.hash_announcer.announce_queue)
        }


class FileManagerComponent(Component):
    component_name = FILE_MANAGER_COMPONENT
    depends_on = [BLOB_COMPONENT, DATABASE_COMPONENT, WALLET_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.file_manager: typing.Optional[FileManager] = None

    @property
    def component(self) -> typing.Optional[FileManager]:
        return self.file_manager

    async def get_status(self):
        if not self.file_manager:
            return
        return {
            'managed_files': len(self.file_manager.get_filtered()),
        }

    async def start(self):
        blob_manager = self.component_manager.get_component(BLOB_COMPONENT)
        storage = self.component_manager.get_component(DATABASE_COMPONENT)
        wallet = self.component_manager.get_component(WALLET_COMPONENT)
        node = self.component_manager.get_component(DHT_COMPONENT) \
            if self.component_manager.has_component(DHT_COMPONENT) else None
        try:
            torrent = self.component_manager.get_component(LIBTORRENT_COMPONENT) if TorrentSession else None
        except NameError:
            torrent = None
        log.info('Starting the file manager')
        loop = asyncio.get_event_loop()
        self.file_manager = FileManager(
            loop, self.conf, wallet, storage, self.component_manager.analytics_manager
        )
        self.file_manager.source_managers['stream'] = StreamManager(
            loop, self.conf, blob_manager, wallet, storage, node,
        )
        if TorrentSession and LIBTORRENT_COMPONENT not in self.conf.components_to_skip:
            self.file_manager.source_managers['torrent'] = TorrentManager(
                loop, self.conf, torrent, storage, self.component_manager.analytics_manager
            )
        await self.file_manager.start()
        log.info('Done setting up file manager')

    async def stop(self):
        self.file_manager.stop()


class BackgroundDownloader(Component):
    component_name = BACKGROUND_DOWNLOADER_COMPONENT
    depends_on = [DATABASE_COMPONENT, BLOB_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.task: typing.Optional[asyncio.Task] = None
        self.download_loop_delay_seconds = 60
        self.finished_iteration = asyncio.Event()
        self.requested_blobs = deque(maxlen=10)
        self.ongoing_download: typing.Optional[asyncio.Task] = None

    @property
    def component(self) -> 'BackgroundDownloader':
        return self

    async def get_status(self):
        return {'running': self.task is not None and not self.task.done(), 'enqueued': len(self.requested_blobs)}

    async def loop(self):
        while True:
            if self.component_manager.has_component(DHT_COMPONENT):
                node = self.component_manager.get_component(DHT_COMPONENT)
                self.requested_blobs = node.protocol.data_store.requested_blobs
            if self.requested_blobs and (not self.ongoing_download or self.ongoing_download.done()):
                blob_hash = self.requested_blobs.pop()
                self.ongoing_download = asyncio.create_task(self.download_blobs(blob_hash))
                self.ongoing_download.add_done_callback(lambda _: self.finished_iteration.set())
            self.finished_iteration.clear()
            await asyncio.sleep(self.download_loop_delay_seconds)

    async def download_blobs(self, sd_hash):
        blob_manager = self.component_manager.get_component(BLOB_COMPONENT)
        downloader = StreamDownloader(asyncio.get_running_loop(), self.conf, blob_manager, sd_hash)
        node = None
        if self.component_manager.has_component(DHT_COMPONENT):
            node = self.component_manager.get_component(DHT_COMPONENT)
        try:
            await downloader.start(node, save_stream=False)
        except ValueError:
            return
        for blob_info in downloader.descriptor.blobs[:-1]:
            await downloader.download_stream_blob(blob_info)

    async def start(self):
        self.task = asyncio.create_task(self.loop())

    async def stop(self):
        if self.ongoing_download and not self.ongoing_download.done():
            self.ongoing_download.cancel()
        self.task.cancel()


class DiskSpaceComponent(Component):
    component_name = DISK_SPACE_COMPONENT
    depends_on = [DATABASE_COMPONENT, BLOB_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.disk_space_manager: typing.Optional[DiskSpaceManager] = None

    @property
    def component(self) -> typing.Optional[DiskSpaceManager]:
        return self.disk_space_manager

    async def get_status(self):
        if self.disk_space_manager:
            return {
                'space_used': str(await self.disk_space_manager.get_space_used_mb()),
                'running': self.disk_space_manager.running,
            }
        return {'space_used': '0', 'running': False}

    async def start(self):
        db = self.component_manager.get_component(DATABASE_COMPONENT)
        blob_manager = self.component_manager.get_component(BLOB_COMPONENT)
        self.disk_space_manager = DiskSpaceManager(
            self.conf, db, blob_manager,
            analytics=self.component_manager.analytics_manager
        )
        await self.disk_space_manager.start()

    async def stop(self):
        await self.disk_space_manager.stop()


class TorrentComponent(Component):
    component_name = LIBTORRENT_COMPONENT

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.torrent_session = None

    @property
    def component(self) -> typing.Optional[TorrentSession]:
        return self.torrent_session

    async def get_status(self):
        if not self.torrent_session:
            return
        return {
            'running': True,  # TODO: what to return here?
        }

    async def start(self):
        if TorrentSession:
            self.torrent_session = TorrentSession(asyncio.get_event_loop(), None)
            await self.torrent_session.bind()  # TODO: specify host/port

    async def stop(self):
        if self.torrent_session:
            await self.torrent_session.pause()


class PeerProtocolServerComponent(Component):
    component_name = PEER_PROTOCOL_SERVER_COMPONENT
    depends_on = [UPNP_COMPONENT, BLOB_COMPONENT, WALLET_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.blob_server: typing.Optional[BlobServer] = None

    @property
    def component(self) -> typing.Optional[BlobServer]:
        return self.blob_server

    async def start(self):
        log.info("start blob server")
        blob_manager: BlobManager = self.component_manager.get_component(BLOB_COMPONENT)
        wallet: WalletManager = self.component_manager.get_component(WALLET_COMPONENT)
        peer_port = self.conf.tcp_port
        address = await wallet.get_unused_address()
        self.blob_server = BlobServer(asyncio.get_event_loop(), blob_manager, address)
        self.blob_server.start_server(peer_port, interface=self.conf.network_interface)
        await self.blob_server.started_listening.wait()

    async def stop(self):
        if self.blob_server:
            self.blob_server.stop_server()


class UPnPComponent(Component):
    component_name = UPNP_COMPONENT

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self._int_peer_port = self.conf.tcp_port
        self._int_dht_node_port = self.conf.udp_port
        self.use_upnp = self.conf.use_upnp
        self.upnp: typing.Optional[UPnP] = None
        self.upnp_redirects = {}
        self.external_ip: typing.Optional[str] = None
        self._maintain_redirects_task = None

    @property
    def component(self) -> 'UPnPComponent':
        return self

    async def _repeatedly_maintain_redirects(self, now=True):
        while True:
            if now:
                await self._maintain_redirects()
            await asyncio.sleep(360, loop=self.component_manager.loop)

    async def _maintain_redirects(self):
        # setup the gateway if necessary
        if not self.upnp:
            try:
                self.upnp = await UPnP.discover(loop=self.component_manager.loop)
                log.info("found upnp gateway: %s", self.upnp.gateway.manufacturer_string)
            except Exception as err:
                if isinstance(err, asyncio.CancelledError):  # TODO: remove when updated to 3.8
                    raise
                log.warning("upnp discovery failed: %s", err)
                self.upnp = None

        # update the external ip
        external_ip = None
        if self.upnp:
            try:
                external_ip = await self.upnp.get_external_ip()
                if external_ip != "0.0.0.0" and not self.external_ip:
                    log.info("got external ip from UPnP: %s", external_ip)
            except (asyncio.TimeoutError, UPnPError, NotImplementedError):
                pass
        if external_ip and not is_valid_public_ipv4(external_ip):
            log.warning("UPnP returned a private/reserved ip - %s, checking lbry.com fallback", external_ip)
            external_ip, _ = await utils.get_external_ip(self.conf.lbryum_servers)
        if self.external_ip and self.external_ip != external_ip:
            log.info("external ip changed from %s to %s", self.external_ip, external_ip)
        if external_ip:
            self.external_ip = external_ip
            dht_component = self.component_manager.get_component(DHT_COMPONENT)
            if dht_component:
                dht_node = dht_component.component
                dht_node.protocol.external_ip = external_ip
        # assert self.external_ip is not None   # TODO: handle going/starting offline

        if not self.upnp_redirects and self.upnp:  # setup missing redirects
            log.info("add UPnP port mappings")
            upnp_redirects = {}
            if PEER_PROTOCOL_SERVER_COMPONENT not in self.component_manager.skip_components:
                try:
                    upnp_redirects["TCP"] = await self.upnp.get_next_mapping(
                        self._int_peer_port, "TCP", "LBRY peer port", self._int_peer_port
                    )
                except (UPnPError, asyncio.TimeoutError, NotImplementedError):
                    pass
            if DHT_COMPONENT not in self.component_manager.skip_components:
                try:
                    upnp_redirects["UDP"] = await self.upnp.get_next_mapping(
                        self._int_dht_node_port, "UDP", "LBRY DHT port", self._int_dht_node_port
                    )
                except (UPnPError, asyncio.TimeoutError, NotImplementedError):
                    pass
            if upnp_redirects:
                log.info("set up redirects: %s", upnp_redirects)
                self.upnp_redirects.update(upnp_redirects)
        elif self.upnp:  # check existing redirects are still active
            found = set()
            mappings = await self.upnp.get_redirects()
            for mapping in mappings:
                proto = mapping.protocol
                if proto in self.upnp_redirects and mapping.external_port == self.upnp_redirects[proto]:
                    if mapping.lan_address == self.upnp.lan_address:
                        found.add(proto)
            if 'UDP' not in found and DHT_COMPONENT not in self.component_manager.skip_components:
                try:
                    udp_port = await self.upnp.get_next_mapping(self._int_dht_node_port, "UDP", "LBRY DHT port")
                    self.upnp_redirects['UDP'] = udp_port
                    log.info("refreshed upnp redirect for dht port: %i", udp_port)
                except (asyncio.TimeoutError, UPnPError, NotImplementedError):
                    del self.upnp_redirects['UDP']
            if 'TCP' not in found and PEER_PROTOCOL_SERVER_COMPONENT not in self.component_manager.skip_components:
                try:
                    tcp_port = await self.upnp.get_next_mapping(self._int_peer_port, "TCP", "LBRY peer port")
                    self.upnp_redirects['TCP'] = tcp_port
                    log.info("refreshed upnp redirect for peer port: %i", tcp_port)
                except (asyncio.TimeoutError, UPnPError, NotImplementedError):
                    del self.upnp_redirects['TCP']
            if ('TCP' in self.upnp_redirects and
                    PEER_PROTOCOL_SERVER_COMPONENT not in self.component_manager.skip_components) and \
                    ('UDP' in self.upnp_redirects and DHT_COMPONENT not in self.component_manager.skip_components):
                if self.upnp_redirects:
                    log.debug("upnp redirects are still active")

    async def start(self):
        log.info("detecting external ip")
        if not self.use_upnp:
            self.external_ip, _ = await utils.get_external_ip(self.conf.lbryum_servers)
            return
        success = False
        await self._maintain_redirects()
        if self.upnp:
            if not self.upnp_redirects and not all(
                    x in self.component_manager.skip_components
                    for x in (DHT_COMPONENT, PEER_PROTOCOL_SERVER_COMPONENT)
            ):
                log.error("failed to setup upnp")
            else:
                success = True
                if self.upnp_redirects:
                    log.debug("set up upnp port redirects for gateway: %s", self.upnp.gateway.manufacturer_string)
        else:
            log.error("failed to setup upnp")
        if not self.external_ip:
            self.external_ip, probed_url = await utils.get_external_ip(self.conf.lbryum_servers)
            if self.external_ip:
                log.info("detected external ip using %s fallback", probed_url)
        if self.component_manager.analytics_manager:
            self.component_manager.loop.create_task(
                self.component_manager.analytics_manager.send_upnp_setup_success_fail(
                    success, await self.get_status()
                )
            )
        self._maintain_redirects_task = self.component_manager.loop.create_task(
            self._repeatedly_maintain_redirects(now=False)
        )

    async def stop(self):
        if self.upnp_redirects:
            log.info("Removing upnp redirects: %s", self.upnp_redirects)
            await asyncio.wait([
                self.upnp.delete_port_mapping(port, protocol) for protocol, port in self.upnp_redirects.items()
            ], loop=self.component_manager.loop)
        if self._maintain_redirects_task and not self._maintain_redirects_task.done():
            self._maintain_redirects_task.cancel()

    async def get_status(self):
        return {
            'aioupnp_version': aioupnp_version,
            'redirects': self.upnp_redirects,
            'gateway': 'No gateway found' if not self.upnp else self.upnp.gateway.manufacturer_string,
            'dht_redirect_set': 'UDP' in self.upnp_redirects,
            'peer_redirect_set': 'TCP' in self.upnp_redirects,
            'external_ip': self.external_ip
        }


class ExchangeRateManagerComponent(Component):
    component_name = EXCHANGE_RATE_MANAGER_COMPONENT

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.exchange_rate_manager = ExchangeRateManager()

    @property
    def component(self) -> ExchangeRateManager:
        return self.exchange_rate_manager

    async def start(self):
        self.exchange_rate_manager.start()

    async def stop(self):
        self.exchange_rate_manager.stop()