import logging
import asyncio
import json
import socket
import random
from time import perf_counter
from collections import defaultdict
from typing import Dict, Optional, Tuple
import aiohttp
import grpc
from lbry.schema.types.v2 import hub_pb2_grpc
from lbry.schema.types.v2.hub_pb2 import SearchRequest
from lbry import __version__
from lbry.utils import resolve_host
from lbry.error import IncompatibleWalletServerError
from lbry.wallet.rpc import RPCSession as BaseClientSession, Connector, RPCError, ProtocolError
from lbry.wallet.stream import StreamController
from lbry.wallet.server.udp import SPVStatusClientProtocol, SPVPong
from lbry.conf import KnownHubsList
log = logging.getLogger(__name__)
class ClientSession(BaseClientSession):
def __init__(self, *args, network: 'Network', server, timeout=30, concurrency=32, **kwargs):
self.network = network
self.server = server
super().__init__(*args, **kwargs)
self.framer.max_size = self.max_errors = 1 << 32
self.timeout = timeout
self.max_seconds_idle = timeout * 2
self.response_time: Optional[float] = None
self.connection_latency: Optional[float] = None
self._response_samples = 0
self._concurrency = asyncio.Semaphore(concurrency)
@property
def concurrency(self):
return self._concurrency._value
@property
def available(self):
return not self.is_closing() and self.response_time is not None
@property
def server_address_and_port(self) -> Optional[Tuple[str, int]]:
if not self.transport:
return None
return self.transport.get_extra_info('peername')
async def send_timed_server_version_request(self, args=(), timeout=None):
timeout = timeout or self.timeout
log.debug("send version request to %s:%i", *self.server)
start = perf_counter()
result = await asyncio.wait_for(
super().send_request('server.version', args), timeout=timeout
)
current_response_time = perf_counter() - start
response_sum = (self.response_time or 0) * self._response_samples + current_response_time
self.response_time = response_sum / (self._response_samples + 1)
self._response_samples += 1
return result
async def send_request(self, method, args=()):
log.debug("send %s%s to %s:%i (%i timeout)", method, tuple(args), self.server[0], self.server[1], self.timeout)
try:
await self._concurrency.acquire()
if method == 'server.version':
return await self.send_timed_server_version_request(args, self.timeout)
request = asyncio.ensure_future(super().send_request(method, args))
while not request.done():
done, pending = await asyncio.wait([request], timeout=self.timeout)
if pending:
log.debug("Time since last packet: %s", perf_counter() - self.last_packet_received)
if (perf_counter() - self.last_packet_received) < self.timeout:
continue
log.warning("timeout sending %s to %s:%i", method, *self.server)
raise asyncio.TimeoutError
if done:
try:
return request.result()
except ConnectionResetError:
log.error(
"wallet server (%s) reset connection upon our %s request, json of %i args is %i bytes",
self.server[0], method, len(args), len(json.dumps(args))
)
raise
except (RPCError, ProtocolError) as e:
log.warning("Wallet server (%s:%i) returned an error. Code: %s Message: %s",
*self.server, *e.args)
raise e
except ConnectionError:
log.warning("connection to %s:%i lost", *self.server)
self.synchronous_close()
raise
except asyncio.CancelledError:
log.warning("cancelled sending %s to %s:%i", method, *self.server)
# self.synchronous_close()
raise
finally:
self._concurrency.release()
async def ensure_server_version(self, required=None, timeout=3):
required = required or self.network.PROTOCOL_VERSION
response = await asyncio.wait_for(
self.send_request('server.version', [__version__, required]), timeout=timeout
)
if tuple(int(piece) for piece in response[0].split(".")) < self.network.MINIMUM_REQUIRED:
raise IncompatibleWalletServerError(*self.server)
return response
async def keepalive_loop(self, timeout=3, max_idle=60):
try:
while True:
now = perf_counter()
if min(self.last_send, self.last_packet_received) + max_idle < now:
await asyncio.wait_for(
self.send_request('server.ping', []), timeout=timeout
)
else:
await asyncio.sleep(max(0, max_idle - (now - self.last_send)))
except Exception as err:
if isinstance(err, asyncio.CancelledError):
log.warning("closing connection to %s:%i", *self.server)
else:
log.exception("lost connection to spv")
finally:
if not self.is_closing():
self._close()
async def create_connection(self, timeout=6):
connector = Connector(lambda: self, *self.server)
start = perf_counter()
await asyncio.wait_for(connector.create_connection(), timeout=timeout)
self.connection_latency = perf_counter() - start
async def handle_request(self, request):
controller = self.network.subscription_controllers[request.method]
controller.add(request.args)
def connection_lost(self, exc):
log.warning("Connection lost: %s:%d", *self.server)
super().connection_lost(exc)
self.response_time = None
self.connection_latency = None
self._response_samples = 0
# self._on_disconnect_controller.add(True)
if self.network:
self.network.disconnect()
class Network:
PROTOCOL_VERSION = __version__
MINIMUM_REQUIRED = (0, 65, 0)
def __init__(self, ledger):
self.ledger = ledger
self.client: Optional[ClientSession] = None
self.server_features = None
# self._switch_task: Optional[asyncio.Task] = None
self.running = False
self.remote_height: int = 0
self._on_connected_controller = StreamController()
self.on_connected = self._on_connected_controller.stream
self._on_header_controller = StreamController(merge_repeated_events=True)
self.on_header = self._on_header_controller.stream
self._on_status_controller = StreamController(merge_repeated_events=True)
self.on_status = self._on_status_controller.stream
self._on_hub_controller = StreamController(merge_repeated_events=True)
self.on_hub = self._on_hub_controller.stream
self.subscription_controllers = {
'blockchain.headers.subscribe': self._on_header_controller,
'blockchain.address.subscribe': self._on_status_controller,
'blockchain.peers.subscribe': self._on_hub_controller,
}
self.aiohttp_session: Optional[aiohttp.ClientSession] = None
self._urgent_need_reconnect = asyncio.Event()
self._loop_task: Optional[asyncio.Task] = None
self._keepalive_task: Optional[asyncio.Task] = None
@property
def config(self):
return self.ledger.config
@property
def known_hubs(self):
if 'known_hubs' not in self.config:
return KnownHubsList()
return self.config['known_hubs']
@property
def jurisdiction(self):
return self.config.get("jurisdiction")
def disconnect(self):
if self._keepalive_task and not self._keepalive_task.done():
self._keepalive_task.cancel()
self._keepalive_task = None
async def start(self):
if not self.running:
self.running = True
self.aiohttp_session = aiohttp.ClientSession()
self.on_header.listen(self._update_remote_height)
self.on_hub.listen(self._update_hubs)
self._loop_task = asyncio.create_task(self.network_loop())
self._urgent_need_reconnect.set()
def loop_task_done_callback(f):
try:
f.result()
except Exception:
if self.running:
log.exception("wallet server connection loop crashed")
self._loop_task.add_done_callback(loop_task_done_callback)
async def resolve_spv_dns(self):
hostname_to_ip = {}
ip_to_hostnames = defaultdict(list)
async def resolve_spv(server, port):
try:
server_addr = await resolve_host(server, port, 'udp')
hostname_to_ip[server] = (server_addr, port)
ip_to_hostnames[(server_addr, port)].append(server)
except socket.error:
log.warning("error looking up dns for spv server %s:%i", server, port)
except Exception:
log.exception("error looking up dns for spv server %s:%i", server, port)
# accumulate the dns results
if self.config['explicit_servers']:
hubs = self.config['explicit_servers']
elif self.known_hubs:
hubs = self.known_hubs
else:
hubs = self.config['default_servers']
await asyncio.gather(*(resolve_spv(server, port) for (server, port) in hubs))
return hostname_to_ip, ip_to_hostnames
async def get_n_fastest_spvs(self, timeout=3.0) -> Dict[Tuple[str, int], Optional[SPVPong]]:
loop = asyncio.get_event_loop()
pong_responses = asyncio.Queue()
connection = SPVStatusClientProtocol(pong_responses)
sent_ping_timestamps = {}
_, ip_to_hostnames = await self.resolve_spv_dns()
n = len(ip_to_hostnames)
log.info("%i possible spv servers to try (%i urls in config)", n, len(self.config['explicit_servers']))
pongs = {}
known_hubs = self.known_hubs
try:
await loop.create_datagram_endpoint(lambda: connection, ('0.0.0.0', 0))
# could raise OSError if it cant bind
start = perf_counter()
for server in ip_to_hostnames:
connection.ping(server)
sent_ping_timestamps[server] = perf_counter()
while len(pongs) < n:
(remote, ts), pong = await asyncio.wait_for(pong_responses.get(), timeout - (perf_counter() - start))
latency = ts - start
log.info("%s:%i has latency of %sms (available: %s, height: %i)",
'/'.join(ip_to_hostnames[remote]), remote[1], round(latency * 1000, 2),
pong.available, pong.height)
known_hubs.hubs.setdefault((ip_to_hostnames[remote][0], remote[1]), {}).update(
{"country": pong.country_name}
)
if pong.available:
pongs[(ip_to_hostnames[remote][0], remote[1])] = pong
return pongs
except asyncio.TimeoutError:
if pongs:
log.info("%i/%i probed spv servers are accepting connections", len(pongs), len(ip_to_hostnames))
return pongs
else:
log.warning("%i spv status probes failed, retrying later. servers tried: %s",
len(sent_ping_timestamps),
', '.join('/'.join(hosts) + f' ({ip})' for ip, hosts in ip_to_hostnames.items()))
random_server = random.choice(list(ip_to_hostnames.keys()))
host, port = random_server
log.warning("trying fallback to randomly selected spv: %s:%i", host, port)
known_hubs.hubs.setdefault((host, port), {})
return {(host, port): None}
finally:
connection.close()
async def connect_to_fastest(self) -> Optional[ClientSession]:
fastest_spvs = await self.get_n_fastest_spvs()
for (host, port), pong in fastest_spvs.items():
if (pong is not None and self.jurisdiction is not None) and \
(pong.country_name != self.jurisdiction):
continue
client = ClientSession(network=self, server=(host, port), timeout=self.config['hub_timeout'],
concurrency=self.config['concurrent_hub_requests'])
try:
await client.create_connection()
log.warning("Connected to spv server %s:%i", host, port)
await client.ensure_server_version()
return client
except (asyncio.TimeoutError, ConnectionError, OSError, IncompatibleWalletServerError, RPCError):
log.warning("Connecting to %s:%d failed", host, port)
client._close()
return
async def network_loop(self):
sleep_delay = 30
while self.running:
await asyncio.wait(
[asyncio.sleep(30), self._urgent_need_reconnect.wait()], return_when=asyncio.FIRST_COMPLETED
)
if self._urgent_need_reconnect.is_set():
sleep_delay = 30
self._urgent_need_reconnect.clear()
if not self.is_connected:
client = await self.connect_to_fastest()
if not client:
log.warning("failed to connect to any spv servers, retrying later")
sleep_delay *= 2
sleep_delay = min(sleep_delay, 300)
continue
log.debug("get spv server features %s:%i", *client.server)
features = await client.send_request('server.features', [])
self.client, self.server_features = client, features
log.debug("discover other hubs %s:%i", *client.server)
await self._update_hubs(await client.send_request('server.peers.subscribe', []))
log.info("subscribe to headers %s:%i", *client.server)
self._update_remote_height((await self.subscribe_headers(),))
self._on_connected_controller.add(True)
server_str = "%s:%i" % client.server
log.info("maintaining connection to spv server %s", server_str)
self._keepalive_task = asyncio.create_task(self.client.keepalive_loop())
try:
if not self._urgent_need_reconnect.is_set():
await asyncio.wait(
[self._keepalive_task, self._urgent_need_reconnect.wait()],
return_when=asyncio.FIRST_COMPLETED
)
else:
await self._keepalive_task
if self._urgent_need_reconnect.is_set():
log.warning("urgent reconnect needed")
self._urgent_need_reconnect.clear()
if self._keepalive_task and not self._keepalive_task.done():
self._keepalive_task.cancel()
except asyncio.CancelledError:
pass
finally:
self._keepalive_task = None
self.client = None
self.server_features = None
log.warning("connection lost to %s", server_str)
log.info("network loop finished")
async def stop(self):
self.running = False
self.disconnect()
if self._loop_task and not self._loop_task.done():
self._loop_task.cancel()
self._loop_task = None
if self.aiohttp_session:
await self.aiohttp_session.close()
self.aiohttp_session = None
@property
def is_connected(self):
return self.client and not self.client.is_closing()
def rpc(self, list_or_method, args, restricted=True, session: Optional[ClientSession] = None):
if session or self.is_connected:
session = session or self.client
return session.send_request(list_or_method, args)
else:
self._urgent_need_reconnect.set()
raise ConnectionError("Attempting to send rpc request when connection is not available.")
async def retriable_call(self, function, *args, **kwargs):
while self.running:
if not self.is_connected:
log.warning("Wallet server unavailable, waiting for it to come back and retry.")
self._urgent_need_reconnect.set()
await self.on_connected.first
try:
return await function(*args, **kwargs)
except asyncio.TimeoutError:
log.warning("Wallet server call timed out, retrying.")
except ConnectionError:
log.warning("connection error")
raise asyncio.CancelledError() # if we got here, we are shutting down
def _update_remote_height(self, header_args):
self.remote_height = header_args[0]["height"]
async def _update_hubs(self, hubs):
if hubs and hubs != ['']:
try:
if self.known_hubs.add_hubs(hubs):
self.known_hubs.save()
except Exception:
log.exception("could not add hubs: %s", hubs)
def get_transaction(self, tx_hash, known_height=None):
# use any server if its old, otherwise restrict to who gave us the history
restricted = known_height in (None, -1, 0) or 0 > known_height > self.remote_height - 10
return self.rpc('blockchain.transaction.get', [tx_hash], restricted)
def get_transaction_batch(self, txids, restricted=True):
# use any server if its old, otherwise restrict to who gave us the history
return self.rpc('blockchain.transaction.get_batch', txids, restricted)
def get_transaction_and_merkle(self, tx_hash, known_height=None):
# use any server if its old, otherwise restrict to who gave us the history
restricted = known_height in (None, -1, 0) or 0 > known_height > self.remote_height - 10
return self.rpc('blockchain.transaction.info', [tx_hash], restricted)
def get_transaction_height(self, tx_hash, known_height=None):
restricted = not known_height or 0 > known_height > self.remote_height - 10
return self.rpc('blockchain.transaction.get_height', [tx_hash], restricted)
def get_merkle(self, tx_hash, height):
restricted = 0 > height > self.remote_height - 10
return self.rpc('blockchain.transaction.get_merkle', [tx_hash, height], restricted)
def get_headers(self, height, count=10000, b64=False):
restricted = height >= self.remote_height - 100
return self.rpc('blockchain.block.headers', [height, count, 0, b64], restricted)
# --- Subscribes, history and broadcasts are always aimed towards the master client directly
def get_history(self, address):
return self.rpc('blockchain.address.get_history', [address], True)
def broadcast(self, raw_transaction):
return self.rpc('blockchain.transaction.broadcast', [raw_transaction], True)
def subscribe_headers(self):
return self.rpc('blockchain.headers.subscribe', [True], True)
async def subscribe_address(self, address, *addresses):
addresses = list((address, ) + addresses)
server_addr_and_port = self.client.server_address_and_port # on disconnect client will be None
try:
return await self.rpc('blockchain.address.subscribe', addresses, True)
except asyncio.TimeoutError:
log.warning(
"timed out subscribing to addresses from %s:%i",
*server_addr_and_port
)
# abort and cancel, we can't lose a subscription, it will happen again on reconnect
if self.client:
self.client.abort()
raise asyncio.CancelledError()
def unsubscribe_address(self, address):
return self.rpc('blockchain.address.unsubscribe', [address], True)
def get_server_features(self):
return self.rpc('server.features', (), restricted=True)
# def get_claims_by_ids(self, claim_ids):
# return self.rpc('blockchain.claimtrie.getclaimsbyids', claim_ids)
def get_claim_by_id(self, claim_id):
return self.rpc('blockchain.claimtrie.getclaimbyid', [claim_id])
def resolve(self, urls, session_override=None):
return self.rpc('blockchain.claimtrie.resolve', urls, False, session_override)
def claim_search(self, session_override=None, **kwargs):
return self.rpc('blockchain.claimtrie.search', kwargs, False, session_override)
async def new_resolve(self, server, urls):
message = {"method": "resolve", "params": {"urls": urls, "protobuf": True}}
async with self.aiohttp_session.post(server, json=message) as r:
result = await r.json()
return result['result']
async def new_claim_search(self, server, **kwargs):
async with grpc.aio.insecure_channel(server) as channel:
stub = hub_pb2_grpc.HubStub(channel)
try:
response = await stub.Search(SearchRequest(**kwargs))
except grpc.aio.AioRpcError as error:
raise RPCError(error.code(), error.details())
return response
async def sum_supports(self, server, **kwargs):
message = {"method": "support_sum", "params": kwargs}
async with self.aiohttp_session.post(server, json=message) as r:
result = await r.json()
return result['result']