sanic/sanic/asgi.py
2022-06-27 11:19:26 +03:00

238 lines
8.1 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 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 self.asgi_app.sanic_app.config.USE_UVLOOP is not _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":
await self.startup()
await send({"type": "lifespan.startup.complete"})
message = await receive()
if message["type"] == "lifespan.shutdown":
await self.shutdown()
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:
await self.sanic_app.handle_exception(self.request, e)