sanic/sanic/asgi.py
2022-12-16 08:56:07 +02:00

255 lines
8.7 KiB
Python

from __future__ import annotations
import warnings
from typing import TYPE_CHECKING, Optional
from urllib.parse import quote
from sanic.compat import Header
from sanic.exceptions import ServerError
from sanic.helpers import Default
from sanic.http import Stage
from sanic.log import error_logger, logger
from sanic.models.asgi import ASGIReceive, ASGIScope, ASGISend, MockTransport
from sanic.request import Request
from sanic.response import BaseHTTPResponse
from sanic.server import ConnInfo
from sanic.server.websockets.connection import WebSocketConnection
if TYPE_CHECKING:
from sanic import Sanic
class Lifespan:
def __init__(self, asgi_app: ASGIApp) -> None:
self.asgi_app = asgi_app
if (
"server.init.before"
in self.asgi_app.sanic_app.signal_router.name_index
):
logger.debug(
'You have set a listener for "before_server_start" '
"in ASGI mode. "
"It will be executed as early as possible, but not before "
"the ASGI server is started.",
extra={"verbosity": 1},
)
if (
"server.shutdown.after"
in self.asgi_app.sanic_app.signal_router.name_index
):
logger.debug(
'You have set a listener for "after_server_stop" '
"in ASGI mode. "
"It will be executed as late as possible, but not after "
"the ASGI server is stopped.",
extra={"verbosity": 1},
)
async def startup(self) -> None:
"""
Gather the listeners to fire on server start.
Because we are using a third-party server and not Sanic server, we do
not have access to fire anything BEFORE the server starts.
Therefore, we fire before_server_start and after_server_start
in sequence since the ASGI lifespan protocol only supports a single
startup event.
"""
await self.asgi_app.sanic_app._startup()
await self.asgi_app.sanic_app._server_event("init", "before")
await self.asgi_app.sanic_app._server_event("init", "after")
if not isinstance(self.asgi_app.sanic_app.config.USE_UVLOOP, Default):
warnings.warn(
"You have set the USE_UVLOOP configuration option, but Sanic "
"cannot control the event loop when running in ASGI mode."
"This option will be ignored."
)
async def shutdown(self) -> None:
"""
Gather the listeners to fire on server stop.
Because we are using a third-party server and not Sanic server, we do
not have access to fire anything AFTER the server stops.
Therefore, we fire before_server_stop and after_server_stop
in sequence since the ASGI lifespan protocol only supports a single
shutdown event.
"""
await self.asgi_app.sanic_app._server_event("shutdown", "before")
await self.asgi_app.sanic_app._server_event("shutdown", "after")
async def __call__(
self, scope: ASGIScope, receive: ASGIReceive, send: ASGISend
) -> None:
message = await receive()
if message["type"] == "lifespan.startup":
try:
await self.startup()
except Exception as e:
error_logger.exception(e)
await send(
{"type": "lifespan.startup.failed", "message": str(e)}
)
else:
await send({"type": "lifespan.startup.complete"})
message = await receive()
if message["type"] == "lifespan.shutdown":
try:
await self.shutdown()
except Exception as e:
error_logger.exception(e)
await send(
{"type": "lifespan.shutdown.failed", "message": str(e)}
)
else:
await send({"type": "lifespan.shutdown.complete"})
class ASGIApp:
sanic_app: Sanic
request: Request
transport: MockTransport
lifespan: Lifespan
ws: Optional[WebSocketConnection]
stage: Stage
response: Optional[BaseHTTPResponse]
def __init__(self) -> None:
self.ws = None
@classmethod
async def create(
cls, sanic_app, scope: ASGIScope, receive: ASGIReceive, send: ASGISend
) -> "ASGIApp":
instance = cls()
instance.sanic_app = sanic_app
instance.transport = MockTransport(scope, receive, send)
instance.transport.loop = sanic_app.loop
instance.stage = Stage.IDLE
instance.response = None
setattr(instance.transport, "add_task", sanic_app.loop.create_task)
headers = Header(
[
(key.decode("latin-1"), value.decode("latin-1"))
for key, value in scope.get("headers", [])
]
)
instance.lifespan = Lifespan(instance)
if scope["type"] == "lifespan":
await instance.lifespan(scope, receive, send)
else:
path = (
scope["path"][1:]
if scope["path"].startswith("/")
else scope["path"]
)
url = "/".join([scope.get("root_path", ""), quote(path)])
url_bytes = url.encode("latin-1")
url_bytes += b"?" + scope["query_string"]
if scope["type"] == "http":
version = scope["http_version"]
method = scope["method"]
elif scope["type"] == "websocket":
version = "1.1"
method = "GET"
instance.ws = instance.transport.create_websocket_connection(
send, receive
)
else:
raise ServerError("Received unknown ASGI scope")
request_class = sanic_app.request_class or Request
instance.request = request_class(
url_bytes,
headers,
version,
method,
instance.transport,
sanic_app,
)
instance.request.stream = instance
instance.request_body = True
instance.request.conn_info = ConnInfo(instance.transport)
await sanic_app.dispatch(
"http.lifecycle.request",
inline=True,
context={"request": instance.request},
fail_not_found=False,
)
return instance
async def read(self) -> Optional[bytes]:
"""
Read and stream the body in chunks from an incoming ASGI message.
"""
if self.stage is Stage.IDLE:
self.stage = Stage.REQUEST
message = await self.transport.receive()
body = message.get("body", b"")
if not message.get("more_body", False):
self.request_body = False
if not body:
return None
return body
async def __aiter__(self):
while self.request_body:
data = await self.read()
if data:
yield data
def respond(self, response: BaseHTTPResponse):
if self.stage is not Stage.HANDLER:
self.stage = Stage.FAILED
raise RuntimeError("Response already started")
if self.response is not None:
self.response.stream = None
response.stream, self.response = self, response
return response
async def send(self, data, end_stream):
self.stage = Stage.IDLE if end_stream else Stage.RESPONSE
if self.response:
response, self.response = self.response, None
await self.transport.send(
{
"type": "http.response.start",
"status": response.status,
"headers": response.processed_headers,
}
)
response_body = getattr(response, "body", None)
if response_body:
data = response_body + data if data else response_body
await self.transport.send(
{
"type": "http.response.body",
"body": data.encode() if hasattr(data, "encode") else data,
"more_body": not end_stream,
}
)
_asgi_single_callable = True # We conform to ASGI 3.0 single-callable
async def __call__(self) -> None:
"""
Handle the incoming request.
"""
try:
self.stage = Stage.HANDLER
await self.sanic_app.handle_request(self.request)
except Exception as e:
try:
await self.sanic_app.handle_exception(self.request, e)
except Exception as exc:
await self.sanic_app.handle_exception(self.request, exc, False)