Files
bitfinex-api-py/bfxapi/websocket/_client/bfx_websocket_client.py

287 lines
12 KiB
Python

from collections import namedtuple
from datetime import datetime
import traceback, json, asyncio, hmac, hashlib, time, socket, random, websockets
from pyee.asyncio import AsyncIOEventEmitter
from .bfx_websocket_bucket import require_websocket_connection, BfxWebSocketBucket
from .bfx_websocket_inputs import BfxWebSocketInputs
from .._handlers import PublicChannelsHandler, AuthEventsHandler
from ..exceptions import ActionRequiresAuthentication, InvalidAuthenticationCredentials, EventNotSupported, \
ZeroConnectionsError, ReconnectionTimeoutError, OutdatedClientVersion
from ...utils.json_encoder import JSONEncoder
from ...utils.logger import ColorLogger, FileLogger
def require_websocket_authentication(function):
async def wrapper(self, *args, **kwargs):
if hasattr(self, "authentication") and not self.authentication:
raise ActionRequiresAuthentication("To perform this action you need to " \
"authenticate using your API_KEY and API_SECRET.")
await require_websocket_connection(function) \
(self, *args, **kwargs)
return wrapper
class _Delay:
BACKOFF_MIN, BACKOFF_MAX = 1.92, 60.0
BACKOFF_INITIAL = 5.0
def __init__(self, backoff_factor):
self.__backoff_factor = backoff_factor
self.__backoff_delay = _Delay.BACKOFF_MIN
self.__initial_delay = random.random() * _Delay.BACKOFF_INITIAL
def next(self):
backoff_delay = self.peek()
__backoff_delay = self.__backoff_delay * self.__backoff_factor
self.__backoff_delay = min(__backoff_delay, _Delay.BACKOFF_MAX)
return backoff_delay
def peek(self):
return (self.__backoff_delay == _Delay.BACKOFF_MIN) \
and self.__initial_delay or self.__backoff_delay
class BfxWebSocketClient:
VERSION = BfxWebSocketBucket.VERSION
MAXIMUM_CONNECTIONS_AMOUNT = 20
ONCE_EVENTS = [
"open", "authenticated", "disconnection",
*AuthEventsHandler.ONCE_EVENTS
]
EVENTS = [
"subscribed", "wss-error",
*ONCE_EVENTS,
*PublicChannelsHandler.EVENTS,
*AuthEventsHandler.ON_EVENTS
]
def __init__(self, host, credentials, *, wss_timeout = 60 * 15, log_filename = None, log_level = "INFO"):
self.websocket, self.authentication, self.buckets = None, False, []
self.host, self.credentials, self.wss_timeout = host, credentials, wss_timeout
self.event_emitter = AsyncIOEventEmitter()
self.handler = AuthEventsHandler(event_emitter=self.event_emitter)
self.inputs = BfxWebSocketInputs(handle_websocket_input=self.__handle_websocket_input)
if log_filename is None:
self.logger = ColorLogger("BfxWebSocketClient", level=log_level)
else: self.logger = FileLogger("BfxWebSocketClient", level=log_level, filename=log_filename)
self.event_emitter.add_listener("error",
lambda exception: self.logger.error(f"{type(exception).__name__}: {str(exception)}" + "\n" +
str().join(traceback.format_exception(type(exception), exception, exception.__traceback__))[:-1])
)
def run(self, connections = 5):
return asyncio.run(self.start(connections))
async def start(self, connections = 5):
if connections == 0:
self.logger.info("With connections set to 0 it will not be possible to subscribe to any public channel. " \
"Attempting a subscription will cause a ZeroConnectionsError to be thrown.")
if connections > BfxWebSocketClient.MAXIMUM_CONNECTIONS_AMOUNT:
self.logger.warning(f"It is not safe to use more than {BfxWebSocketClient.MAXIMUM_CONNECTIONS_AMOUNT} " \
f"buckets from the same connection ({connections} in use), the server could momentarily " \
"block the client with <429 Too Many Requests>.")
for _ in range(connections):
self.buckets += [BfxWebSocketBucket(self.host, self.event_emitter)]
await self.__connect()
#pylint: disable-next=too-many-statements,too-many-branches
async def __connect(self):
Reconnection = namedtuple("Reconnection", ["status", "attempts", "timestamp"])
reconnection = Reconnection(status=False, attempts=0, timestamp=None)
timer, tasks, on_timeout_event = None, [], asyncio.locks.Event()
delay = None
def _on_wss_timeout():
on_timeout_event.set()
#pylint: disable-next=too-many-branches
async def _connection():
nonlocal reconnection, timer, tasks
async with websockets.connect(self.host, ping_interval=None) as websocket:
if reconnection.status:
self.logger.info(f"Reconnection attempt successful (no.{reconnection.attempts}): The " \
f"client has been offline for a total of {datetime.now() - reconnection.timestamp} " \
f"(connection lost on: {reconnection.timestamp:%d-%m-%Y at %H:%M:%S}).")
reconnection = Reconnection(status=False, attempts=0, timestamp=None)
if isinstance(timer, asyncio.events.TimerHandle):
timer.cancel()
self.websocket = websocket
coroutines = [ BfxWebSocketBucket.connect(bucket) for bucket in self.buckets ]
tasks = [ asyncio.create_task(coroutine) for coroutine in coroutines ]
if len(self.buckets) == 0 or \
(await asyncio.gather(*[bucket.wait() for bucket in self.buckets])):
self.event_emitter.emit("open")
if self.credentials:
await self.__authenticate(**self.credentials)
async for message in websocket:
message = json.loads(message)
if isinstance(message, dict):
if message["event"] == "info" and "version" in message:
if BfxWebSocketClient.VERSION != message["version"]:
raise OutdatedClientVersion("Mismatch between the client version and the server " \
"version. Update the library to the latest version to continue (client version: " \
f"{BfxWebSocketClient.VERSION}, server version: {message['version']}).")
elif message["event"] == "info" and message["code"] == 20051:
rcvd = websockets.frames.Close(code=1012,
reason="Stop/Restart WebSocket Server (please reconnect).")
raise websockets.exceptions.ConnectionClosedError(rcvd=rcvd, sent=None)
elif message["event"] == "auth":
if message["status"] != "OK":
raise InvalidAuthenticationCredentials(
"Cannot authenticate with given API-KEY and API-SECRET.")
self.event_emitter.emit("authenticated", message)
self.authentication = True
elif message["event"] == "error":
self.event_emitter.emit("wss-error", message["code"], message["msg"])
if isinstance(message, list):
if message[0] == 0 and message[1] != "hb":
self.handler.handle(message[1], message[2])
while True:
if reconnection.status:
await asyncio.sleep(delay.next())
if on_timeout_event.is_set():
raise ReconnectionTimeoutError("Connection has been offline for too long " \
f"without being able to reconnect (wss_timeout: {self.wss_timeout}s).")
try:
await _connection()
except (websockets.exceptions.ConnectionClosedError, socket.gaierror) as error:
for task in tasks:
task.cancel()
if isinstance(error, websockets.exceptions.ConnectionClosedError) and error.code in (1006, 1012):
if error.code == 1006:
self.logger.error("Connection lost: no close frame received " \
"or sent (1006). Trying to reconnect...")
if error.code == 1012:
self.logger.info("WSS server is about to restart, clients need " \
"to reconnect (server sent 20051). Reconnection attempt in progress...")
reconnection = Reconnection(status=True, attempts=1, timestamp=datetime.now())
if self.wss_timeout is not None:
timer = asyncio.get_event_loop().call_later(self.wss_timeout, _on_wss_timeout)
delay = _Delay(backoff_factor=1.618)
self.authentication = False
elif isinstance(error, socket.gaierror) and reconnection.status:
self.logger.warning(f"Reconnection attempt was unsuccessful (no.{reconnection.attempts}). " \
f"Next reconnection attempt in {delay.peek():.2f} seconds. (at the moment " \
f"the client has been offline for {datetime.now() - reconnection.timestamp})")
reconnection = reconnection._replace(attempts=reconnection.attempts + 1)
else:
raise error
if not reconnection.status:
self.event_emitter.emit("disconnection",
self.websocket.close_code, self.websocket.close_reason)
break
async def __authenticate(self, api_key, api_secret, filters=None):
data = { "event": "auth", "filter": filters, "apiKey": api_key }
data["authNonce"] = str(round(time.time() * 1_000_000))
data["authPayload"] = "AUTH" + data["authNonce"]
data["authSig"] = hmac.new(
api_secret.encode("utf8"),
data["authPayload"].encode("utf8"),
hashlib.sha384
).hexdigest()
await self.websocket.send(json.dumps(data))
async def subscribe(self, channel, **kwargs):
if len(self.buckets) == 0:
raise ZeroConnectionsError("Unable to subscribe: the number of connections must be greater than 0.")
counters = [ len(bucket.pendings) + len(bucket.subscriptions) for bucket in self.buckets ]
index = counters.index(min(counters))
await self.buckets[index].subscribe(channel, **kwargs)
async def unsubscribe(self, sub_id):
for bucket in self.buckets:
if (chan_id := bucket.get_chan_id(sub_id)):
await bucket.unsubscribe(chan_id=chan_id)
async def close(self, code=1000, reason=str()):
for bucket in self.buckets:
await bucket.close(code=code, reason=reason)
if self.websocket is not None and self.websocket.open:
await self.websocket.close(code=code, reason=reason)
@require_websocket_authentication
async def notify(self, info, message_id=None, **kwargs):
await self.websocket.send(json.dumps([ 0, "n", message_id, { "type": "ucm-test", "info": info, **kwargs } ]))
@require_websocket_authentication
async def __handle_websocket_input(self, event, data):
await self.websocket.send(json.dumps([ 0, event, None, data], cls=JSONEncoder))
def on(self, *events, callback = None):
for event in events:
if event not in BfxWebSocketClient.EVENTS:
raise EventNotSupported(f"Event <{event}> is not supported. To get a list " \
"of available events print BfxWebSocketClient.EVENTS")
def _register_event(event, function):
if event in BfxWebSocketClient.ONCE_EVENTS:
self.event_emitter.once(event, function)
else: self.event_emitter.on(event, function)
if callback is not None:
for event in events:
_register_event(event, callback)
if callback is None:
def handler(function):
for event in events:
_register_event(event, function)
return handler