import asyncio
import ssl
import traceback
from collections.abc import Coroutine
from concurrent.futures import CancelledError
from functools import partial
from pathlib import Path
import aiohttp_cors
from aiohttp import web
from params_proto import Proto
[docs]async def default_handler(request, ws):
async for msg in ws:
print(msg)
[docs]async def websocket_handler(request, handler, **ws_kwargs):
ws = web.WebSocketResponse(**ws_kwargs)
await ws.prepare(request)
try:
await handler(request, ws)
except ConnectionResetError:
print("Connection reset")
except CancelledError:
print("WebSocket Canceled")
except Exception as exp:
print(f"Error:\n{exp}\n{traceback.print_exc()}")
finally:
await ws.close()
print("WebSocket connection closed")
[docs]async def handle_file_request(request, root, filename=None):
if filename is None:
filename = request.match_info["filename"]
filepath = Path(root) / filename
if not filepath.is_file():
raise web.HTTPNotFound()
response = web.FileResponse(filepath)
# Check if URL contains "hot" parameter for hot loading mode
# Hot assets are those that change frequently during development
# Parameter name is case-insensitive (hot, Hot, HOT all work)
# Parameter value must not equal "false" (case insensitive)
hot_key = None
for key in request.query.keys():
if key.lower() == "hot":
hot_key = key
break
if hot_key:
# Check if hot is explicitly set to false
hot_value = request.query.get(hot_key, "")
if hot_value.lower() != "false":
# Set Cache-Control to no-cache to force revalidation
# This allows 304 responses but prevents strong caching
response.headers["Cache-Control"] = "no-cache"
return response
[docs]class Server:
"""Base TCP server"""
host = Proto(env="HOST", default="localhost")
cors = Proto(help="Enable CORS", default="*")
port = Proto(env="PORT", default=8012)
cert = Proto(None, dtype=str, help="the path to the SSL certificate")
key = Proto(None, dtype=str, help="the path to the SSL key")
ca_cert = Proto(None, dtype=str, help="the trusted root CA certificates")
WEBSOCKET_MAX_SIZE: int = Proto(
2**28,
env="WEBSOCKET_MAX_SIZE",
help="maximum size for websocket requests.",
)
REQUEST_MAX_SIZE: int = Proto(
2**28,
env="REQUEST_MAX_SIZE",
help="maximum size for requests.",
)
[docs] def __post_init__(self):
self.app = web.Application(client_max_size=self.REQUEST_MAX_SIZE)
default = aiohttp_cors.ResourceOptions(
allow_credentials=True,
expose_headers="*",
allow_headers="*",
allow_methods="*",
)
cors_config = {k: default for k in self.cors.split(",")}
self.cors_context = aiohttp_cors.setup(self.app, defaults=cors_config)
[docs] def _add_route(
self,
path: str,
handler: callable,
method: str = "GET",
):
route = self.app.router.add_resource(path).add_route(method, handler)
self.cors_context.add(route)
[docs] def _socket(self, path: str, handler: callable):
ws_handler = partial(websocket_handler, handler=handler, max_msg_size=self.WEBSOCKET_MAX_SIZE)
self._add_route(path, ws_handler)
[docs] @staticmethod
def _add_task(fn: Coroutine, name=None):
loop = asyncio.get_running_loop()
loop.create_task(fn, name=name)
[docs] def _add_static(self, path, root):
_fn = partial(handle_file_request, root=root)
self._add_route(f"{path}/{{filename:.*}}", _fn, method="GET")
[docs] def _static_file(self, path, root, filename=None):
_fn = partial(handle_file_request, root=root, filename=filename)
self._add_route(f"{path}", _fn, method="GET")
[docs] def start(self):
async def init_server():
runner = web.AppRunner(self.app)
await runner.setup()
if not self.cert:
site = web.TCPSite(runner, self.host, self.port)
return await site.start()
ssl_context = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
ssl_context.load_cert_chain(certfile=self.cert, keyfile=self.key)
if self.ca_cert:
ssl_context.load_verify_locations(self.ca_cert)
ssl_context.verify_mode = ssl.CERT_REQUIRED
else:
ssl_context.verify_mode = ssl.CERT_OPTIONAL
site = web.TCPSite(runner, self.host, self.port, ssl_context=ssl_context)
return await site.start()
# Check if there's already a running event loop (e.g., in IPython/Jupyter)
try:
running_loop = asyncio.get_running_loop()
# If we're here, there's a running loop - schedule the server to start
asyncio.ensure_future(init_server(), loop=running_loop)
print("Server scheduled in existing event loop (IPython/Jupyter mode)")
return
except RuntimeError:
# No running loop, proceed with standard approach
pass
# Standard approach for scripts/CLI
try:
event_loop = asyncio.get_event_loop()
except RuntimeError:
# Python 3.10+ in some environments
event_loop = asyncio.new_event_loop()
asyncio.set_event_loop(event_loop)
event_loop.run_until_complete(init_server())
event_loop.run_forever()
if __name__ == "__main__":
app = Server()
app._add_route("", websocket_handler)
app._add_static("/static", ".")
app.start()