piker/piker/brokers/kraken.py

582 lines
17 KiB
Python

# piker: trading gear for hackers
# Copyright (C) Tyler Goodlet (in stewardship for piker0)
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
"""
Kraken backend.
"""
from contextlib import asynccontextmanager
from dataclasses import asdict, field
from typing import List, Dict, Any, Tuple, Optional
import time
from trio_typing import TaskStatus
import trio
import arrow
import asks
from fuzzywuzzy import process as fuzzy
import numpy as np
import tractor
from pydantic.dataclasses import dataclass
from pydantic import BaseModel
import wsproto
from .._cacheables import open_cached_client
from ._util import resproc, SymbolNotFound, BrokerError
from ..log import get_logger, get_console_log
from ..data import ShmArray
from ..data._web_bs import open_autorecon_ws
log = get_logger(__name__)
# <uri>/<version>/
_url = 'https://api.kraken.com/0'
# Broker specific ohlc schema which includes a vwap field
_ohlc_dtype = [
('index', int),
('time', int),
('open', float),
('high', float),
('low', float),
('close', float),
('volume', float),
('count', int),
('bar_wap', float),
]
# UI components allow this to be declared such that additional
# (historical) fields can be exposed.
ohlc_dtype = np.dtype(_ohlc_dtype)
_show_wap_in_history = True
_symbol_info_translation: Dict[str, str] = {
'tick_decimals': 'pair_decimals',
}
# https://www.kraken.com/features/api#get-tradable-pairs
class Pair(BaseModel):
altname: str # alternate pair name
wsname: str # WebSocket pair name (if available)
aclass_base: str # asset class of base component
base: str # asset id of base component
aclass_quote: str # asset class of quote component
quote: str # asset id of quote component
lot: str # volume lot size
pair_decimals: int # scaling decimal places for pair
lot_decimals: int # scaling decimal places for volume
# amount to multiply lot volume by to get currency volume
lot_multiplier: float
# array of leverage amounts available when buying
leverage_buy: List[int]
# array of leverage amounts available when selling
leverage_sell: List[int]
# fee schedule array in [volume, percent fee] tuples
fees: List[Tuple[int, float]]
# maker fee schedule array in [volume, percent fee] tuples (if on
# maker/taker)
fees_maker: List[Tuple[int, float]]
fee_volume_currency: str # volume discount currency
margin_call: str # margin call level
margin_stop: str # stop-out/liquidation margin level
ordermin: float # minimum order volume for pair
@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)
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)'
})
self._pairs: list[str] = []
@property
def pairs(self) -> Dict[str, Any]:
if self._pairs is None:
raise RuntimeError(
"Make sure to run `cache_symbols()` on startup!"
)
# retreive and cache all symbols
return self._pairs
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: Optional[str] = None,
):
if pair is not None:
pairs = {'pair': pair}
else:
pairs = None # get all pairs
resp = await self._public('AssetPairs', pairs)
err = resp['error']
if err:
symbolname = pairs['pair'] if pair else None
raise SymbolNotFound(f'{symbolname}.kraken')
pairs = resp['result']
if pair is not None:
_, data = next(iter(pairs.items()))
return data
else:
return pairs
async def cache_symbols(
self,
) -> dict:
if not self._pairs:
self._pairs = await self.symbol_info()
return self._pairs
async def search_symbols(
self,
pattern: str,
limit: int = None,
) -> Dict[str, Any]:
if self._pairs is not None:
data = self._pairs
else:
data = await self.symbol_info()
matches = fuzzy.extractBests(
pattern,
data,
score_cutoff=50,
)
# repack in dict form
return {item[0]['altname']: item[0] for item in matches}
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()))
new_bars = []
first = bars[0]
last_nz_vwap = first[-3]
if last_nz_vwap == 0:
# use close if vwap is zero
last_nz_vwap = first[-4]
# convert all fields to native types
for i, bar in enumerate(bars):
# normalize weird zero-ed vwap values..cmon kraken..
# indicates vwap didn't change since last bar
vwap = float(bar.pop(-3))
if vwap != 0:
last_nz_vwap = vwap
if vwap == 0:
vwap = last_nz_vwap
# re-insert vwap as the last of the fields
bar.append(vwap)
new_bars.append(
(i,) + tuple(
ftype(bar[j]) for j, (name, ftype) in enumerate(
_ohlc_dtype[1:]
)
)
)
array = np.array(new_bars, dtype=_ohlc_dtype) if as_np else bars
return array
except KeyError:
raise SymbolNotFound(json['error'][0] + f': {symbol}')
@asynccontextmanager
async def get_client() -> Client:
client = Client()
# at startup, load all symbols locally for fast search
await client.cache_symbols()
yield client
async def stream_messages(ws):
too_slow_count = last_hb = 0
while True:
with trio.move_on_after(5) as cs:
msg = await ws.recv_msg()
# trigger reconnection if heartbeat is laggy
if cs.cancelled_caught:
too_slow_count += 1
if too_slow_count > 20:
log.warning(
"Heartbeat is too slow, resetting ws connection")
await ws._connect()
too_slow_count = 0
continue
if isinstance(msg, dict):
if msg.get('event') == 'heartbeat':
now = time.time()
delay = now - last_hb
last_hb = now
# XXX: why tf is this not printing without --tl flag?
log.debug(f"Heartbeat after {delay}")
# print(f"Heartbeat after {delay}")
continue
err = msg.get('errorMessage')
if err:
raise BrokerError(err)
else:
chan_id, *payload_array, chan_name, pair = msg
if 'ohlc' in chan_name:
yield 'ohlc', OHLC(chan_id, chan_name, pair, *payload_array[0])
elif 'spread' in chan_name:
bid, ask, ts, bsize, asize = map(float, payload_array[0])
# TODO: really makes you think IB has a horrible API...
quote = {
'symbol': pair.replace('/', ''),
'ticks': [
{'type': 'bid', 'price': bid, 'size': bsize},
{'type': 'bsize', 'price': bid, 'size': bsize},
{'type': 'ask', 'price': ask, 'size': asize},
{'type': 'asize', 'price': ask, 'size': asize},
],
}
yield 'l1', quote
# elif 'book' in msg[-2]:
# chan_id, *payload_array, chan_name, pair = msg
# print(msg)
else:
print(f'UNHANDLED MSG: {msg}')
def normalize(
ohlc: OHLC,
) -> dict:
quote = asdict(ohlc)
quote['broker_ts'] = quote['time']
quote['brokerd_ts'] = time.time()
quote['symbol'] = quote['pair'] = quote['pair'].replace('/', '')
quote['last'] = quote['close']
quote['bar_wap'] = ohlc.vwap
# seriously eh? what's with this non-symmetry everywhere
# in subscription systems...
# XXX: piker style is always lowercases symbols.
topic = quote['pair'].replace('/', '').lower()
# print(quote)
return topic, quote
def make_sub(pairs: List[str], data: Dict[str, Any]) -> Dict[str, str]:
"""Create a request subscription packet dict.
https://docs.kraken.com/websockets/#message-subscribe
"""
# eg. specific logic for this in kraken's sync client:
# https://github.com/krakenfx/kraken-wsclient-py/blob/master/kraken_wsclient_py/kraken_wsclient_py.py#L188
return {
'pair': pairs,
'event': 'subscribe',
'subscription': data,
}
async def backfill_bars(
sym: str,
shm: ShmArray, # type: ignore # noqa
count: int = 10, # NOTE: any more and we'll overrun the underlying buffer
task_status: TaskStatus[trio.CancelScope] = trio.TASK_STATUS_IGNORED,
) -> None:
"""Fill historical bars into shared mem / storage afap.
"""
with trio.CancelScope() as cs:
async with open_cached_client('kraken') as client:
bars = await client.bars(symbol=sym)
shm.push(bars)
task_status.started(cs)
async def stream_quotes(
send_chan: trio.abc.SendChannel,
symbols: List[str],
feed_is_live: trio.Event,
loglevel: str = None,
# backend specific
sub_type: str = 'ohlc',
# startup sync
task_status: TaskStatus[Tuple[Dict, Dict]] = trio.TASK_STATUS_IGNORED,
) -> 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 = {}
sym_infos = {}
async with open_cached_client('kraken') as client, send_chan as send_chan:
# keep client cached for real-time section
for sym in symbols:
# transform to upper since piker style is always lower
sym = sym.upper()
si = Pair(**await client.symbol_info(sym)) # validation
syminfo = si.dict()
syminfo['price_tick_size'] = 1 / 10**si.pair_decimals
syminfo['lot_tick_size'] = 1 / 10**si.lot_decimals
syminfo['asset_type'] = 'crypto'
sym_infos[sym] = syminfo
ws_pairs[sym] = si.wsname
symbol = symbols[0].lower()
init_msgs = {
# pass back token, and bool, signalling if we're the writer
# and that history has been written
symbol: {
'symbol_info': sym_infos[sym],
'shm_write_opts': {'sum_tick_vml': False},
},
}
@asynccontextmanager
async def subscribe(ws: wsproto.WSConnection):
# XXX: setup subs
# https://docs.kraken.com/websockets/#message-subscribe
# specific logic for this in kraken's shitty sync client:
# https://github.com/krakenfx/kraken-wsclient-py/blob/master/kraken_wsclient_py/kraken_wsclient_py.py#L188
ohlc_sub = make_sub(
list(ws_pairs.values()),
{'name': 'ohlc', 'interval': 1}
)
# 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_msg(ohlc_sub)
# trade data (aka L1)
l1_sub = make_sub(
list(ws_pairs.values()),
{'name': 'spread'} # 'depth': 10}
)
# pull a first quote and deliver
await ws.send_msg(l1_sub)
yield
# unsub from all pairs on teardown
await ws.send_msg({
'pair': list(ws_pairs.values()),
'event': 'unsubscribe',
'subscription': ['ohlc', 'spread'],
})
# XXX: do we need to ack the unsub?
# await ws.recv_msg()
# see the tips on reonnection logic:
# https://support.kraken.com/hc/en-us/articles/360044504011-WebSocket-API-unexpected-disconnections-from-market-data-feeds
async with open_autorecon_ws(
'wss://ws.kraken.com/',
fixture=subscribe,
) as ws:
# pull a first quote and deliver
msg_gen = stream_messages(ws)
# TODO: use ``anext()`` when it lands in 3.10!
typ, ohlc_last = await msg_gen.__anext__()
topic, quote = normalize(ohlc_last)
first_quote = {topic: quote}
task_status.started((init_msgs, first_quote))
# lol, only "closes" when they're margin squeezing clients ;P
feed_is_live.set()
# keep start of last interval for volume tracking
last_interval_start = ohlc_last.etime
# start streaming
async for typ, ohlc in msg_gen:
if typ == 'ohlc':
# TODO: can get rid of all this by using
# ``trades`` subscription...
# generate tick values to match time & sales pane:
# https://trade.kraken.com/charts/KRAKEN:BTC-USD?period=1m
volume = ohlc.volume
# new OHLC sample interval
if ohlc.etime > last_interval_start:
last_interval_start = ohlc.etime
tick_volume = volume
else:
# this is the tick volume *within the interval*
tick_volume = volume - ohlc_last.volume
ohlc_last = ohlc
last = ohlc.close
if tick_volume:
ohlc.ticks.append({
'type': 'trade',
'price': last,
'size': tick_volume,
})
topic, quote = normalize(ohlc)
elif typ == 'l1':
quote = ohlc
topic = quote['symbol'].lower()
await send_chan.send({topic: quote})
@tractor.context
async def open_symbol_search(
ctx: tractor.Context,
) -> Client:
async with open_cached_client('kraken') as client:
# load all symbols locally for fast search
cache = await client.cache_symbols()
await ctx.started(cache)
async with ctx.open_stream() as stream:
async for pattern in stream:
matches = fuzzy.extractBests(
pattern,
cache,
score_cutoff=50,
)
# repack in dict form
await stream.send(
{item[0]['altname']: item[0]
for item in matches}
)