37172-vm/algo_trader/core/data_feed.py
2025-12-27 04:12:50 +00:00

90 lines
3.4 KiB
Python

"""Core: WebSocket market data feed."""
import asyncio
from typing import Awaitable, Callable
from fyers_api_sdk.fyers_async import FyersAsync
from loguru import logger
class FyersDataFeed:
"""Handles WebSocket connection for real-time data."""
def __init__(
self,
fyers: FyersAsync,
on_connect: Callable[[], Awaitable[None]],
on_tick: Callable[[dict], Awaitable[None]],
on_close: Callable[[], Awaitable[None]] | None = None,
on_error: Callable[[str], Awaitable[None]] | None = None,
):
"""
Initializes the FyersDataFeed.
Args:
fyers: An authenticated FyersAsync instance.
on_connect: Async callback to run on successful connection.
on_tick: Async callback to process each incoming tick.
on_close: Async callback for when the connection closes.
on_error: Async callback to handle errors.
"""
self._fyers = fyers
self._on_connect = on_connect
self._on_tick = on_tick
self._on_close = on_close
self._on_error = on_error
self.websocket = None
async def connect(self, access_token: str, data_type: str = "symbolData"):
"""Establishes a WebSocket connection."""
logger.info("Connecting to Fyers WebSocket...")
try:
self.websocket = self._fyers.fyers_market_socket(
access_token=access_token,
log_path="", # Disable log file generation
on_connect=lambda: asyncio.create_task(self._on_connect()),
on_close=lambda: asyncio.create_task(self._handle_close()),
on_error=lambda msg: asyncio.create_task(self._handle_error(msg)),
on_message=lambda msg: asyncio.create_task(self._on_tick(msg)),
)
await asyncio.to_thread(self.websocket.connect)
logger.success("Fyers WebSocket connected.")
except Exception as e:
logger.error(f"Failed to connect to WebSocket: {e}")
if self._on_error:
await self._on_error(str(e))
async def subscribe(self, symbols: list[str]):
"""Subscribes to a list of symbols."""
if self.websocket:
logger.info(f"Subscribing to symbols: {symbols}")
request = {"T": "SUB_L2", "L2_T": "T", "V": symbols}
self.websocket.send_message(request)
else:
logger.warning("WebSocket not connected. Cannot subscribe.")
async def unsubscribe(self, symbols: list[str]):
"""Unsubscribes from a list of symbols."""
if self.websocket:
logger.info(f"Unsubscribing from symbols: {symbols}")
request = {"T": "UNSUB_L2", "V": symbols}
self.websocket.send_message(request)
else:
logger.warning("WebSocket not connected. Cannot unsubscribe.")
async def close(self):
"""Closes the WebSocket connection."""
if self.websocket:
logger.info("Closing WebSocket connection.")
self.websocket.close()
async def _handle_close(self):
"""Internal handler for close events."""
logger.info("WebSocket connection closed.")
if self._on_close:
await self._on_close()
async def _handle_error(self, message: str):
"""Internal handler for error events."""
logger.error(f"WebSocket error: {message}")
if self._on_error:
await self._on_error(message)