WIP

sanic/app.py

@@ -60,7 +60,7 @@ from sanic.exceptions import (
     ServerError,
     URLBuildError,
 )
-from sanic.handlers import ErrorHandler
+from sanic.handlers import ErrorHandler, RequestManager
 from sanic.helpers import _default
 from sanic.http import Stage
 from sanic.log import (
@@ -705,6 +705,14 @@ class Sanic(BaseSanic, RunnerMixin, metaclass=TouchUpMeta):
         request: Request,
         exception: BaseException,
         run_middleware: bool = True,
+    ):  # no cov
+        raise NotImplementedError
+
+    async def _handle_exception(
+        self,
+        request: Request,
+        exception: BaseException,
+        run_middleware: bool = True,
     ):  # no cov
         """
         A handler that catches specific exceptions and outputs a response.
@@ -830,6 +838,8 @@ class Sanic(BaseSanic, RunnerMixin, metaclass=TouchUpMeta):
         :param request: HTTP Request object
         :return: Nothing
         """
+
+    async def _handle_request(self, request: Request):  # no cov
         await self.dispatch(
             "http.lifecycle.handle",
             inline=True,

sanic/asgi.py

@@ -7,6 +7,7 @@ from urllib.parse import quote
 
 from sanic.compat import Header
 from sanic.exceptions import ServerError
+from sanic.handlers import RequestManager
 from sanic.helpers import _default
 from sanic.http import Stage
 from sanic.log import logger
@@ -230,8 +231,9 @@ class ASGIApp:
         """
         Handle the incoming request.
         """
+        manager = RequestManager.create(self.request)
         try:
             self.stage = Stage.HANDLER
-            await self.sanic_app.handle_request(self.request)
+            await manager.handle()
         except Exception as e:
-            await self.sanic_app.handle_exception(self.request, e)
+            await manager.error(e)

sanic/handlers.py

@@ -1,16 +1,319 @@
 from __future__ import annotations
 
+from functools import partial
+from inspect import isawaitable
+from traceback import format_exc
 from typing import Dict, List, Optional, Tuple, Type
 
+from sanic_routing import Route
+
 from sanic.errorpages import BaseRenderer, TextRenderer, exception_response
 from sanic.exceptions import (
     HeaderNotFound,
     InvalidRangeType,
     RangeNotSatisfiable,
+    SanicException,
+    ServerError,
 )
-from sanic.log import deprecation, error_logger
+from sanic.http.constants import Stage
+from sanic.log import deprecation, error_logger, logger
 from sanic.models.handler_types import RouteHandler
-from sanic.response import text
+from sanic.request import Request
+from sanic.response import BaseHTTPResponse, HTTPResponse, ResponseStream, text
+
+
+class RequestHandler:
+    def __init__(self, func, request_middleware, response_middleware):
+        self.func = func
+        self.request_middleware = request_middleware
+        self.response_middleware = response_middleware
+
+    def __call__(self, *args, **kwargs):
+        return self.func(*args, **kwargs)
+
+
+class RequestManager:
+    request: Request
+
+    def __init__(self, request: Request):
+        self.request_middleware_run = False
+        self.response_middleware_run = False
+        self.handler = self._noop
+        self.set_request(request)
+
+    @classmethod
+    def create(cls, request: Request) -> RequestManager:
+        return cls(request)
+
+    def set_request(self, request: Request):
+        request._manager = self
+        self.request = request
+        self.request_middleware = request.app.request_middleware
+        self.response_middleware = request.app.response_middleware
+
+    async def handle(self):
+        route = self.resolve_route()
+
+        if self.handler is None:
+            await self.error(
+                ServerError(
+                    (
+                        "'None' was returned while requesting a "
+                        "handler from the router"
+                    )
+                )
+            )
+            return
+
+        if (
+            self.request.stream
+            and self.request.stream.request_body
+            and not route.ctx.ignore_body
+        ):
+            await self.receive_body()
+
+        await self.lifecycle(
+            partial(self.handler, self.request, **self.request.match_info)
+        )
+
+    async def lifecycle(self, handler):
+        response: Optional[BaseHTTPResponse] = None
+        if not self.request_middleware_run and self.request_middleware:
+            response = await self.run(self.run_request_middleware)
+
+        if not response:
+            # Run response handler
+            response = await self.run(handler)
+
+        if not self.response_middleware_run and self.response_middleware:
+            response = await self.run(
+                partial(self.run_response_middleware, response)
+            )
+
+        await self.cleanup(response)
+
+    async def run(self, operation) -> Optional[BaseHTTPResponse]:
+        try:
+            response = operation()
+            if isawaitable(response):
+                response = await response
+        except Exception as e:
+            response = await self.error(e)
+        return response
+
+    async def error(self, exception: Exception):
+        error_handler = self.request.app.error_handler
+        if (
+            self.request.stream is not None
+            and self.request.stream.stage is not Stage.HANDLER
+        ):
+            error_logger.exception(exception, exc_info=True)
+            logger.error(
+                "The error response will not be sent to the client for "
+                f'the following exception:"{exception}". A previous response '
+                "has at least partially been sent."
+            )
+
+            handler = error_handler._lookup(
+                exception, self.request.name if self.request else None
+            )
+            if handler:
+                logger.warning(
+                    "An error occurred while handling the request after at "
+                    "least some part of the response was sent to the client. "
+                    "The response from your custom exception handler "
+                    f"{handler.__name__} will not be sent to the client."
+                    "Exception handlers should only be used to generate the "
+                    "exception responses. If you would like to perform any "
+                    "other action on a raised exception, consider using a "
+                    "signal handler like "
+                    '`@app.signal("http.lifecycle.exception")`\n'
+                    "For further information, please see the docs: "
+                    "https://sanicframework.org/en/guide/advanced/"
+                    "signals.html",
+                )
+            return
+
+        try:
+            await self.lifecycle(
+                partial(error_handler.response, self.request, exception)
+            )
+        except Exception as e:
+            await self.lifecycle(
+                partial(error_handler.default, self.request, e)
+            )
+            if isinstance(e, SanicException):
+                response = error_handler.default(self.request, e)
+            elif self.request.app.debug:
+                response = HTTPResponse(
+                    (
+                        f"Error while handling error: {e}\n"
+                        f"Stack: {format_exc()}"
+                    ),
+                    status=500,
+                )
+            else:
+                response = HTTPResponse(
+                    "An error occurred while handling an error", status=500
+                )
+            return response
+        return None
+
+    async def cleanup(self, response: Optional[BaseHTTPResponse]):
+        if self.request.responded:
+            if response is not None:
+                error_logger.error(
+                    "The response object returned by the route handler "
+                    "will not be sent to client. The request has already "
+                    "been responded to."
+                )
+            if self.request.stream is not None:
+                response = self.request.stream.response
+        elif response is not None:
+            self.request.reset_response()
+            response = await self.request.respond(response)  # type: ignore
+        elif not hasattr(self.handler, "is_websocket"):
+            response = self.request.stream.response  # type: ignore
+
+        # Marked for cleanup and DRY with handle_request/handle_exception
+        # when ResponseStream is no longer supporder
+        if isinstance(response, BaseHTTPResponse):
+            # await self.dispatch(
+            #     "http.lifecycle.response",
+            #     inline=True,
+            #     context={
+            #         "request": self.request,
+            #         "response": response,
+            #     },
+            # )
+            ...
+            await response.send(end_stream=True)
+        elif isinstance(response, ResponseStream):
+            await response(self.request)  # type: ignore
+            # await self.dispatch(
+            #     "http.lifecycle.response",
+            #     inline=True,
+            #     context={
+            #         "request": self.request,
+            #         "response": resp,
+            #     },
+            # )
+            await response.eof()  # type: ignore
+        else:
+            if not hasattr(self.handler, "is_websocket"):
+                raise ServerError(
+                    f"Invalid response type {response!r} "
+                    "(need HTTPResponse)"
+                )
+
+    async def receive_body(self):
+        if hasattr(self.handler, "is_stream"):
+            # Streaming handler: lift the size limit
+            self.request.stream.request_max_size = float("inf")
+        else:
+            # Non-streaming handler: preload body
+            await self.request.receive_body()
+
+    async def run_request_middleware(self) -> Optional[BaseHTTPResponse]:
+        self.request._request_middleware_started = True
+        self.request_middleware_run = True
+
+        for middleware in self.request_middleware:
+            # await self.dispatch(
+            #     "http.middleware.before",
+            #     inline=True,
+            #     context={
+            #         "request": request,
+            #         "response": None,
+            #     },
+            #     condition={"attach_to": "request"},
+            # )
+
+            response = await self.run(partial(middleware, self.request))
+
+            # await self.dispatch(
+            #     "http.middleware.after",
+            #     inline=True,
+            #     context={
+            #         "request": request,
+            #         "response": None,
+            #     },
+            #     condition={"attach_to": "request"},
+            # )
+
+            if response:
+                return response
+        return None
+
+    async def run_response_middleware(
+        self, response: BaseHTTPResponse
+    ) -> BaseHTTPResponse:
+        self.response_middleware_run = True
+        for middleware in self.response_middleware:
+            # await self.dispatch(
+            #     "http.middleware.before",
+            #     inline=True,
+            #     context={
+            #         "request": request,
+            #         "response": None,
+            #     },
+            #     condition={"attach_to": "request"},
+            # )
+
+            resp = await self.run(partial(middleware, self.request, response))
+
+            # await self.dispatch(
+            #     "http.middleware.after",
+            #     inline=True,
+            #     context={
+            #         "request": request,
+            #         "response": None,
+            #     },
+            #     condition={"attach_to": "request"},
+            # )
+
+            if resp:
+                return resp
+        return response
+        # try:
+        #     middleware = (
+        #         self.route and self.route.extra.response_middleware
+        #     ) or self.app.response_middleware
+        #     if middleware:
+        #         response = await self.app._run_response_middleware(
+        #             self, response, middleware
+        #         )
+        # except CancelledErrors:
+        #     raise
+        # except Exception:
+        #     error_logger.exception(
+        #         "Exception occurred in one of response middleware handlers"
+        #     )
+        # return None
+
+    def resolve_route(self) -> Route:
+        # Fetch handler from router
+        route, handler, kwargs = self.request.app.router.get(
+            self.request.path,
+            self.request.method,
+            self.request.headers.getone("host", None),
+        )
+
+        self.request._match_info = {**kwargs}
+        self.request.route = route
+        self.handler = handler
+
+        if route.handler and route.handler.request_middleware:
+            self.request_middleware = route.handler.request_middleware
+
+        if route.handler and route.handler.response_middleware:
+            self.response_middleware = route.handler.response_middleware
+
+        return route
+
+    @staticmethod
+    def _noop(_):
+        ...
 
 
 class ErrorHandler:

sanic/http/http1.py

@@ -124,7 +124,8 @@ class Http(Stream, metaclass=TouchUpMeta):
 
                 self.stage = Stage.HANDLER
                 self.request.conn_info = self.protocol.conn_info
-                await self.protocol.request_handler(self.request)
+
+                await self.request.manager.handle()
 
                 # Handler finished, response should've been sent
                 if self.stage is Stage.HANDLER and not self.upgrade_websocket:
@@ -246,6 +247,7 @@ class Http(Stream, metaclass=TouchUpMeta):
             transport=self.protocol.transport,
             app=self.protocol.app,
         )
+        self.protocol.request_handler.create(request)
         self.protocol.request_class._current.set(request)
         await self.dispatch(
             "http.lifecycle.request",
@@ -419,12 +421,11 @@ class Http(Stream, metaclass=TouchUpMeta):
 
         # From request and handler states we can respond, otherwise be silent
         if self.stage is Stage.HANDLER:
-            app = self.protocol.app
-
             if self.request is None:
                 self.create_empty_request()
+                self.protocol.request_handler.create(self.request)
 
-            await app.handle_exception(self.request, exception)
+            await self.request.manager.error(exception)
 
     def create_empty_request(self) -> None:
         """

sanic/middleware.py

@@ -33,9 +33,10 @@ class Middleware:
         return self.func(*args, **kwargs)
 
     def __repr__(self) -> str:
+        name = getattr(self.func, "__name__", str(self.func))
         return (
             f"{self.__class__.__name__}("
-            f"func=<function {self.func.__name__}>, "
+            f"func=<function {name}>, "
             f"priority={self.priority}, "
             f"location={self.location.name})"
         )

sanic/mixins/middleware.py

@@ -4,6 +4,7 @@ from operator import attrgetter
 from typing import List
 
 from sanic.base.meta import SanicMeta
+from sanic.handlers import RequestHandler
 from sanic.middleware import Middleware, MiddlewareLocation
 from sanic.models.futures import FutureMiddleware
 from sanic.router import Router
@@ -104,19 +105,23 @@ class MiddlewareMixin(metaclass=SanicMeta):
                 self.named_response_middleware.get(route.name, deque()),
                 location=MiddlewareLocation.RESPONSE,
             )
-            route.extra.request_middleware = deque(
-                sorted(
-                    request_middleware,
-                    key=attrgetter("order"),
-                    reverse=True,
-                )
-            )
-            route.extra.response_middleware = deque(
-                sorted(
-                    response_middleware,
-                    key=attrgetter("order"),
-                    reverse=True,
-                )[::-1]
+
+            route.handler = RequestHandler(
+                route.handler,
+                deque(
+                    sorted(
+                        request_middleware,
+                        key=attrgetter("order"),
+                        reverse=True,
+                    )
+                ),
+                deque(
+                    sorted(
+                        response_middleware,
+                        key=attrgetter("order"),
+                        reverse=True,
+                    )[::-1]
+                ),
             )
         request_middleware = Middleware.convert(
             self.request_middleware,

sanic/request.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from contextvars import ContextVar
+from functools import partial
 from inspect import isawaitable
 from typing import (
     TYPE_CHECKING,
@@ -23,6 +24,7 @@ from sanic.models.http_types import Credentials
 
 
 if TYPE_CHECKING:
+    from sanic.handlers import RequestManager
     from sanic.server import ConnInfo
     from sanic.app import Sanic
 
@@ -37,7 +39,7 @@ from urllib.parse import parse_qs, parse_qsl, unquote, urlunparse
 from httptools import parse_url
 from httptools.parser.errors import HttpParserInvalidURLError
 
-from sanic.compat import CancelledErrors, Header
+from sanic.compat import Header
 from sanic.constants import (
     CACHEABLE_HTTP_METHODS,
     DEFAULT_HTTP_CONTENT_TYPE,
@@ -99,6 +101,7 @@ class Request:
         "_cookies",
         "_id",
         "_ip",
+        "_manager",
         "_parsed_url",
         "_port",
         "_protocol",
@@ -182,6 +185,7 @@ class Request:
         self.responded: bool = False
         self.route: Optional[Route] = None
         self.stream: Optional[Stream] = None
+        self._manager: Optional[RequestManager] = None
         self._cookies: Optional[Dict[str, str]] = None
         self._match_info: Dict[str, Any] = {}
         self._protocol = None
@@ -243,6 +247,10 @@ class Request:
             )
         return self._stream_id
 
+    @property
+    def manager(self):
+        return self._manager
+
     def reset_response(self):
         try:
             if (
@@ -333,19 +341,13 @@ class Request:
             if isawaitable(response):
                 response = await response  # type: ignore
         # Run response middleware
-        try:
-            middleware = (
-                self.route and self.route.extra.response_middleware
-            ) or self.app.response_middleware
-            if middleware:
-                response = await self.app._run_response_middleware(
-                    self, response, middleware
-                )
-        except CancelledErrors:
-            raise
-        except Exception:
-            error_logger.exception(
-                "Exception occurred in one of response middleware handlers"
+        if (
+            self._manager
+            and not self._manager.response_middleware_run
+            and self._manager.response_middleware
+        ):
+            response = await self._manager.run(
+                partial(self._manager.run_response_middleware, response)
             )
         self.responded = True
         return response

sanic/server/protocols/http_protocol.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING, Optional
 
+from sanic.handlers import RequestManager
 from sanic.http.constants import HTTP
 from sanic.http.http3 import Http3
 from sanic.touchup.meta import TouchUpMeta
@@ -53,7 +54,7 @@ class HttpProtocolMixin:
     def _setup(self):
         self.request: Optional[Request] = None
         self.access_log = self.app.config.ACCESS_LOG
-        self.request_handler = self.app.handle_request
+        self.request_handler = RequestManager
         self.error_handler = self.app.error_handler
         self.request_timeout = self.app.config.REQUEST_TIMEOUT
         self.response_timeout = self.app.config.RESPONSE_TIMEOUT

tests/test_app.py

@@ -150,8 +150,11 @@ def test_app_route_raise_value_error(app):
 
 
 def test_app_handle_request_handler_is_none(app, monkeypatch):
+    mock = Mock()
+    mock.handler = None
+
     def mockreturn(*args, **kwargs):
-        return Mock(), None, {}
+        return mock, None, {}
 
     # Not sure how to make app.router.get() return None, so use mock here.
     monkeypatch.setattr(app.router, "get", mockreturn)

tests/test_pipelining.py

@@ -1,4 +1,3 @@
-from httpx import AsyncByteStream
 from sanic_testing.reusable import ReusableClient
 
 from sanic.response import json, text