from fastapi import WebSocket from typing import List import json import logging logger = logging.getLogger(__name__) class ConnectionManager: def __init__(self): # Store active websocket connections self.active_connections: List[WebSocket] = [] async def connect(self, websocket: WebSocket): await websocket.accept() self.active_connections.append(websocket) logger.info(f"WebSocket connected. Total connections: {len(self.active_connections)}") def disconnect(self, websocket: WebSocket): if websocket in self.active_connections: self.active_connections.remove(websocket) logger.info(f"WebSocket disconnected. Total connections: {len(self.active_connections)}") async def broadcast(self, message: dict): """ Broadcast a JSON message to all connected clients. If a connection is dropped, catch the exception and remove it. """ if not self.active_connections: return json_msg = json.dumps(message) dead_connections = [] for connection in self.active_connections: try: await connection.send_text(json_msg) except Exception as e: logger.error(f"Error broadcasting to a client: {e}") dead_connections.append(connection) # Clean up any connections that failed for dead in dead_connections: self.disconnect(dead) # Singleton instance to be used across the app manager = ConnectionManager()