piker/piker/data/_normalize.py

83 lines
2.3 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/>.
'''
Stream format enforcement.
'''
from itertools import chain
from typing import AsyncIterator
def iterticks(
quote: dict,
types: tuple[str] = (
'trade',
'dark_trade',
),
deduplicate_darks: bool = False,
) -> AsyncIterator:
'''
Iterate through ticks delivered per quote cycle.
'''
if deduplicate_darks:
assert 'dark_trade' in types
# print(f"{quote}\n\n")
ticks = quote.get('ticks', ())
trades = {}
darks = {}
if ticks:
# do a first pass and attempt to remove duplicate dark
# trades with the same tick signature.
if deduplicate_darks:
for tick in ticks:
ttype = tick.get('type')
time = tick.get('time', None)
if time:
sig = (
time,
tick['price'],
tick['size']
)
if ttype == 'dark_trade':
darks[sig] = tick
elif ttype == 'trade':
trades[sig] = tick
# filter duplicates
for sig, tick in trades.items():
tick = darks.pop(sig, None)
if tick:
ticks.remove(tick)
# print(f'DUPLICATE {tick}')
# re-insert ticks
ticks.extend(list(chain(trades.values(), darks.values())))
for tick in ticks:
# print(f"{quote['symbol']}: {tick}")
ttype = tick.get('type')
if ttype in types:
yield tick