commit
3c76a3e03d
|
@ -0,0 +1,309 @@
|
|||
"""
|
||||
Kraken backend.
|
||||
"""
|
||||
from contextlib import asynccontextmanager
|
||||
from dataclasses import dataclass, asdict, field
|
||||
from itertools import starmap
|
||||
from typing import List, Dict, Any, Callable
|
||||
import json
|
||||
import time
|
||||
|
||||
import trio_websocket
|
||||
from trio_websocket._impl import ConnectionClosed, DisconnectionTimeout
|
||||
import arrow
|
||||
import asks
|
||||
import numpy as np
|
||||
import trio
|
||||
import tractor
|
||||
|
||||
from ._util import resproc, SymbolNotFound, BrokerError
|
||||
from ..log import get_logger, get_console_log
|
||||
|
||||
log = get_logger(__name__)
|
||||
|
||||
|
||||
# <uri>/<version>/
|
||||
_url = 'https://api.kraken.com/0'
|
||||
|
||||
|
||||
# conversion to numpy worthy types
|
||||
_ohlc_dtype = [
|
||||
('index', int),
|
||||
('time', int),
|
||||
('open', float),
|
||||
('high', float),
|
||||
('low', float),
|
||||
('close', float),
|
||||
('vwap', float),
|
||||
('volume', float),
|
||||
('count', int)
|
||||
]
|
||||
|
||||
# UI components allow this to be declared such that additional
|
||||
# (historical) fields can be exposed.
|
||||
ohlc_dtype = np.dtype(_ohlc_dtype)
|
||||
|
||||
|
||||
class Client:
|
||||
|
||||
def __init__(self) -> None:
|
||||
self._sesh = asks.Session(connections=4)
|
||||
self._sesh.base_location = _url
|
||||
self._sesh.headers.update({
|
||||
'User-Agent':
|
||||
'krakenex/2.1.0 (+https://github.com/veox/python3-krakenex)'
|
||||
})
|
||||
|
||||
async def _public(
|
||||
self,
|
||||
method: str,
|
||||
data: dict,
|
||||
) -> Dict[str, Any]:
|
||||
resp = await self._sesh.post(
|
||||
path=f'/public/{method}',
|
||||
json=data,
|
||||
timeout=float('inf')
|
||||
)
|
||||
return resproc(resp, log)
|
||||
|
||||
async def symbol_info(
|
||||
self,
|
||||
pair: str = 'all',
|
||||
):
|
||||
resp = await self._public('AssetPairs', {'pair': pair})
|
||||
err = resp['error']
|
||||
if err:
|
||||
raise BrokerError(err)
|
||||
true_pair_key, data = next(iter(resp['result'].items()))
|
||||
return data
|
||||
|
||||
async def bars(
|
||||
self,
|
||||
symbol: str = 'XBTUSD',
|
||||
# UTC 2017-07-02 12:53:20
|
||||
since: int = None,
|
||||
count: int = 720, # <- max allowed per query
|
||||
as_np: bool = True,
|
||||
) -> dict:
|
||||
if since is None:
|
||||
since = arrow.utcnow().floor('minute').shift(
|
||||
minutes=-count).timestamp
|
||||
# UTC 2017-07-02 12:53:20 is oldest seconds value
|
||||
since = str(max(1499000000, since))
|
||||
json = await self._public(
|
||||
'OHLC',
|
||||
data={
|
||||
'pair': symbol,
|
||||
'since': since,
|
||||
},
|
||||
)
|
||||
try:
|
||||
res = json['result']
|
||||
res.pop('last')
|
||||
bars = next(iter(res.values()))
|
||||
|
||||
# convert all fields to native types
|
||||
new_bars = []
|
||||
last_nz_vwap = None
|
||||
for i, bar in enumerate(bars):
|
||||
# normalize weird zero-ed vwap values..cmon kraken..
|
||||
vwap = float(bar[-3])
|
||||
if vwap != 0:
|
||||
last_nz_vwap = vwap
|
||||
if vwap == 0:
|
||||
bar[-3] = last_nz_vwap
|
||||
|
||||
new_bars.append(
|
||||
(i,) + tuple(
|
||||
ftype(bar[j]) for j, (name, ftype) in enumerate(_ohlc_dtype[1:])
|
||||
)
|
||||
)
|
||||
return np.array(new_bars, dtype=_ohlc_dtype) if as_np else bars
|
||||
except KeyError:
|
||||
raise SymbolNotFound(json['error'][0] + f': {symbol}')
|
||||
|
||||
|
||||
@asynccontextmanager
|
||||
async def get_client() -> Client:
|
||||
yield Client()
|
||||
|
||||
|
||||
@dataclass
|
||||
class OHLC:
|
||||
"""Description of the flattened OHLC quote format.
|
||||
|
||||
For schema details see:
|
||||
https://docs.kraken.com/websockets/#message-ohlc
|
||||
"""
|
||||
chan_id: int # internal kraken id
|
||||
chan_name: str # eg. ohlc-1 (name-interval)
|
||||
pair: str # fx pair
|
||||
time: float # Begin time of interval, in seconds since epoch
|
||||
etime: float # End time of interval, in seconds since epoch
|
||||
open: float # Open price of interval
|
||||
high: float # High price within interval
|
||||
low: float # Low price within interval
|
||||
close: float # Close price of interval
|
||||
vwap: float # Volume weighted average price within interval
|
||||
volume: float # Accumulated volume **within interval**
|
||||
count: int # Number of trades within interval
|
||||
# (sampled) generated tick data
|
||||
ticks: List[Any] = field(default_factory=list)
|
||||
|
||||
# XXX: ugh, super hideous.. needs built-in converters.
|
||||
def __post_init__(self):
|
||||
for f, val in self.__dataclass_fields__.items():
|
||||
if f == 'ticks':
|
||||
continue
|
||||
setattr(self, f, val.type(getattr(self, f)))
|
||||
|
||||
|
||||
async def recv_ohlc(recv):
|
||||
too_slow_count = last_hb = 0
|
||||
while True:
|
||||
with trio.move_on_after(1.5) as cs:
|
||||
msg = await recv()
|
||||
|
||||
# trigger reconnection logic if too slow
|
||||
if cs.cancelled_caught:
|
||||
too_slow_count += 1
|
||||
if too_slow_count > 2:
|
||||
log.warning(
|
||||
"Heartbeat is to slow, "
|
||||
"resetting ws connection")
|
||||
raise trio_websocket._impl.ConnectionClosed(
|
||||
"Reset Connection")
|
||||
|
||||
if isinstance(msg, dict):
|
||||
if msg.get('event') == 'heartbeat':
|
||||
now = time.time()
|
||||
delay = now - last_hb
|
||||
last_hb = now
|
||||
log.trace(f"Heartbeat after {delay}")
|
||||
# TODO: hmm i guess we should use this
|
||||
# for determining when to do connection
|
||||
# resets eh?
|
||||
continue
|
||||
err = msg.get('errorMessage')
|
||||
if err:
|
||||
raise BrokerError(err)
|
||||
else:
|
||||
chan_id, ohlc_array, chan_name, pair = msg
|
||||
yield OHLC(chan_id, chan_name, pair, *ohlc_array)
|
||||
|
||||
|
||||
def normalize(
|
||||
ohlc: OHLC,
|
||||
) -> dict:
|
||||
quote = asdict(ohlc)
|
||||
quote['broker_ts'] = quote['time']
|
||||
quote['brokerd_ts'] = time.time()
|
||||
quote['pair'] = quote['pair'].replace('/', '')
|
||||
|
||||
# seriously eh? what's with this non-symmetry everywhere
|
||||
# in subscription systems...
|
||||
topic = quote['pair'].replace('/', '')
|
||||
|
||||
# print(quote)
|
||||
return topic, quote
|
||||
|
||||
|
||||
@tractor.msg.pub
|
||||
async def stream_quotes(
|
||||
get_topics: Callable,
|
||||
# These are the symbols not expected by the ws api
|
||||
# they are looked up inside this routine.
|
||||
symbols: List[str] = ['XBTUSD', 'XMRUSD'],
|
||||
sub_type: str = 'ohlc',
|
||||
loglevel: str = None,
|
||||
) -> None:
|
||||
"""Subscribe for ohlc stream of quotes for ``pairs``.
|
||||
|
||||
``pairs`` must be formatted <crypto_symbol>/<fiat_symbol>.
|
||||
"""
|
||||
# XXX: required to propagate ``tractor`` loglevel to piker logging
|
||||
get_console_log(loglevel or tractor.current_actor().loglevel)
|
||||
|
||||
ws_pairs = {}
|
||||
async with get_client() as client:
|
||||
for sym in symbols:
|
||||
ws_pairs[sym] = (await client.symbol_info(sym))['wsname']
|
||||
|
||||
while True:
|
||||
try:
|
||||
async with trio_websocket.open_websocket_url(
|
||||
'wss://ws.kraken.com',
|
||||
) as ws:
|
||||
# setup subs
|
||||
# see: https://docs.kraken.com/websockets/#message-subscribe
|
||||
subs = {
|
||||
'pair': list(ws_pairs.values()),
|
||||
'event': 'subscribe',
|
||||
'subscription': {
|
||||
'name': sub_type,
|
||||
'interval': 1, # 1 min
|
||||
# 'name': 'ticker',
|
||||
# 'name': 'openOrders',
|
||||
# 'depth': '25',
|
||||
},
|
||||
}
|
||||
# TODO: we want to eventually allow unsubs which should
|
||||
# be completely fine to request from a separate task
|
||||
# since internally the ws methods appear to be FIFO
|
||||
# locked.
|
||||
await ws.send_message(json.dumps(subs))
|
||||
|
||||
async def recv():
|
||||
return json.loads(await ws.get_message())
|
||||
|
||||
# pull a first quote and deliver
|
||||
ohlc_gen = recv_ohlc(recv)
|
||||
ohlc_last = await ohlc_gen.__anext__()
|
||||
|
||||
topic, quote = normalize(ohlc_last)
|
||||
|
||||
# packetize as {topic: quote}
|
||||
yield {topic: quote}
|
||||
|
||||
# keep start of last interval for volume tracking
|
||||
last_interval_start = ohlc_last.etime
|
||||
|
||||
# start streaming
|
||||
async for ohlc in ohlc_gen:
|
||||
|
||||
# generate tick values to match time & sales pane:
|
||||
# https://trade.kraken.com/charts/KRAKEN:BTC-USD?period=1m
|
||||
volume = ohlc.volume
|
||||
if ohlc.etime > last_interval_start: # new interval
|
||||
last_interval_start = ohlc.etime
|
||||
tick_volume = volume
|
||||
else:
|
||||
# this is the tick volume *within the interval*
|
||||
tick_volume = volume - ohlc_last.volume
|
||||
|
||||
if tick_volume:
|
||||
ohlc.ticks.append({
|
||||
'type': 'trade',
|
||||
'price': ohlc.close,
|
||||
'size': tick_volume,
|
||||
})
|
||||
|
||||
topic, quote = normalize(ohlc)
|
||||
|
||||
# XXX: format required by ``tractor.msg.pub``
|
||||
# requires a ``Dict[topic: str, quote: dict]``
|
||||
yield {topic: quote}
|
||||
|
||||
ohlc_last = ohlc
|
||||
|
||||
except (ConnectionClosed, DisconnectionTimeout):
|
||||
log.exception("Good job kraken...reconnecting")
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
|
||||
async def stream_ohlc():
|
||||
async for msg in stream_quotes():
|
||||
print(msg)
|
||||
|
||||
tractor.run(stream_ohlc)
|
|
@ -1164,10 +1164,10 @@ async def stream_quotes(
|
|||
packetizer=partial(
|
||||
packetizer,
|
||||
formatter=formatter,
|
||||
symboal_data=sd,
|
||||
symbol_data=sd,
|
||||
),
|
||||
|
||||
# actual func args
|
||||
# actual target "streaming func" args
|
||||
get_quotes=get_quotes,
|
||||
diff_cached=diff_cached,
|
||||
rate=rate,
|
||||
|
|
Loading…
Reference in New Issue