Begin middleware revamp (#2550)

sanic/mixins/middleware.py

@@ -1,11 +1,17 @@
+from collections import deque
 from functools import partial
+from operator import attrgetter
 from typing import List
 
 from sanic.base.meta import SanicMeta
+from sanic.middleware import Middleware, MiddlewareLocation
 from sanic.models.futures import FutureMiddleware
+from sanic.router import Router
 
 
 class MiddlewareMixin(metaclass=SanicMeta):
+    router: Router
+
     def __init__(self, *args, **kwargs) -> None:
         self._future_middleware: List[FutureMiddleware] = []
 
@@ -13,7 +19,12 @@ class MiddlewareMixin(metaclass=SanicMeta):
         raise NotImplementedError  # noqa
 
     def middleware(
-        self, middleware_or_request, attach_to="request", apply=True
+        self,
+        middleware_or_request,
+        attach_to="request",
+        apply=True,
+        *,
+        priority=0
     ):
         """
         Decorate and register middleware to be called before a request
@@ -30,6 +41,12 @@ class MiddlewareMixin(metaclass=SanicMeta):
         def register_middleware(middleware, attach_to="request"):
             nonlocal apply
 
+            location = (
+                MiddlewareLocation.REQUEST
+                if attach_to == "request"
+                else MiddlewareLocation.RESPONSE
+            )
+            middleware = Middleware(middleware, location, priority=priority)
             future_middleware = FutureMiddleware(middleware, attach_to)
             self._future_middleware.append(future_middleware)
             if apply:
@@ -46,7 +63,7 @@ class MiddlewareMixin(metaclass=SanicMeta):
                 register_middleware, attach_to=middleware_or_request
             )
 
-    def on_request(self, middleware=None):
+    def on_request(self, middleware=None, *, priority=0):
         """Register a middleware to be called before a request is handled.
 
         This is the same as *@app.middleware('request')*.
@@ -54,11 +71,13 @@ class MiddlewareMixin(metaclass=SanicMeta):
         :param: middleware: A callable that takes in request.
         """
         if callable(middleware):
-            return self.middleware(middleware, "request")
+            return self.middleware(middleware, "request", priority=priority)
         else:
-            return partial(self.middleware, attach_to="request")
+            return partial(
+                self.middleware, attach_to="request", priority=priority
+            )
 
-    def on_response(self, middleware=None):
+    def on_response(self, middleware=None, *, priority=0):
         """Register a middleware to be called after a response is created.
 
         This is the same as *@app.middleware('response')*.
@@ -67,6 +86,57 @@ class MiddlewareMixin(metaclass=SanicMeta):
             A callable that takes in a request and its response.
         """
         if callable(middleware):
-            return self.middleware(middleware, "response")
+            return self.middleware(middleware, "response", priority=priority)
         else:
-            return partial(self.middleware, attach_to="response")
+            return partial(
+                self.middleware, attach_to="response", priority=priority
+            )
+
+    def finalize_middleware(self):
+        for route in self.router.routes:
+            request_middleware = Middleware.convert(
+                self.request_middleware,
+                self.named_request_middleware.get(route.name, deque()),
+                location=MiddlewareLocation.REQUEST,
+            )
+            response_middleware = Middleware.convert(
+                self.response_middleware,
+                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]
+            )
+        request_middleware = Middleware.convert(
+            self.request_middleware,
+            location=MiddlewareLocation.REQUEST,
+        )
+        response_middleware = Middleware.convert(
+            self.response_middleware,
+            location=MiddlewareLocation.RESPONSE,
+        )
+        self.request_middleware = deque(
+            sorted(
+                request_middleware,
+                key=attrgetter("order"),
+                reverse=True,
+            )
+        )
+        self.response_middleware = deque(
+            sorted(
+                response_middleware,
+                key=attrgetter("order"),
+                reverse=True,
+            )[::-1]
+        )