Add most of the missing type hints to synapse.federation. (#11483)

This skips a few methods which are difficult to type.

synapse/federation/transport/server/_base.py

@@ -15,10 +15,13 @@
 import functools
 import logging
 import re
+from typing import Any, Awaitable, Callable, Optional, Tuple, cast
 
 from synapse.api.errors import Codes, FederationDeniedError, SynapseError
 from synapse.api.urls import FEDERATION_V1_PREFIX
+from synapse.http.server import HttpServer, ServletCallback
 from synapse.http.servlet import parse_json_object_from_request
+from synapse.http.site import SynapseRequest
 from synapse.logging import opentracing
 from synapse.logging.context import run_in_background
 from synapse.logging.opentracing import (
@@ -29,6 +32,7 @@ from synapse.logging.opentracing import (
     whitelisted_homeserver,
 )
 from synapse.server import HomeServer
+from synapse.types import JsonDict
 from synapse.util.ratelimitutils import FederationRateLimiter
 from synapse.util.stringutils import parse_and_validate_server_name
 
@@ -59,9 +63,11 @@ class Authenticator:
             self.replication_client = hs.get_tcp_replication()
 
     # A method just so we can pass 'self' as the authenticator to the Servlets
-    async def authenticate_request(self, request, content):
+    async def authenticate_request(
+        self, request: SynapseRequest, content: Optional[JsonDict]
+    ) -> str:
         now = self._clock.time_msec()
-        json_request = {
+        json_request: JsonDict = {
             "method": request.method.decode("ascii"),
             "uri": request.uri.decode("ascii"),
             "destination": self.server_name,
@@ -114,7 +120,7 @@ class Authenticator:
 
         return origin
 
-    async def _reset_retry_timings(self, origin):
+    async def _reset_retry_timings(self, origin: str) -> None:
         try:
             logger.info("Marking origin %r as up", origin)
             await self.store.set_destination_retry_timings(origin, None, 0, 0)
@@ -133,14 +139,14 @@ class Authenticator:
             logger.exception("Error resetting retry timings on %s", origin)
 
 
-def _parse_auth_header(header_bytes):
+def _parse_auth_header(header_bytes: bytes) -> Tuple[str, str, str]:
     """Parse an X-Matrix auth header
 
     Args:
-        header_bytes (bytes): header value
+        header_bytes: header value
 
     Returns:
-        Tuple[str, str, str]: origin, key id, signature.
+        origin, key id, signature.
 
     Raises:
         AuthenticationError if the header could not be parsed
@@ -148,9 +154,9 @@ def _parse_auth_header(header_bytes):
     try:
         header_str = header_bytes.decode("utf-8")
         params = header_str.split(" ")[1].split(",")
-        param_dict = dict(kv.split("=") for kv in params)
+        param_dict = {k: v for k, v in (kv.split("=", maxsplit=1) for kv in params)}
 
-        def strip_quotes(value):
+        def strip_quotes(value: str) -> str:
             if value.startswith('"'):
                 return value[1:-1]
             else:
@@ -233,23 +239,25 @@ class BaseFederationServlet:
         self.ratelimiter = ratelimiter
         self.server_name = server_name
 
-    def _wrap(self, func):
+    def _wrap(self, func: Callable[..., Awaitable[Tuple[int, Any]]]) -> ServletCallback:
         authenticator = self.authenticator
         ratelimiter = self.ratelimiter
 
         @functools.wraps(func)
-        async def new_func(request, *args, **kwargs):
+        async def new_func(
+            request: SynapseRequest, *args: Any, **kwargs: str
+        ) -> Optional[Tuple[int, Any]]:
             """A callback which can be passed to HttpServer.RegisterPaths
 
             Args:
-                request (twisted.web.http.Request):
+                request:
                 *args: unused?
-                **kwargs (dict[unicode, unicode]): the dict mapping keys to path
-                    components as specified in the path match regexp.
+                **kwargs: the dict mapping keys to path components as specified
+                    in the path match regexp.
 
             Returns:
-                Tuple[int, object]|None: (response code, response object) as returned by
-                    the callback method. None if the request has already been handled.
+                (response code, response object) as returned by the callback method.
+                None if the request has already been handled.
             """
             content = None
             if request.method in [b"PUT", b"POST"]:
@@ -257,7 +265,9 @@ class BaseFederationServlet:
                 content = parse_json_object_from_request(request)
 
             try:
-                origin = await authenticator.authenticate_request(request, content)
+                origin: Optional[str] = await authenticator.authenticate_request(
+                    request, content
+                )
             except NoAuthenticationError:
                 origin = None
                 if self.REQUIRE_AUTH:
@@ -301,7 +311,7 @@ class BaseFederationServlet:
                                 "client disconnected before we started processing "
                                 "request"
                             )
-                            return -1, None
+                            return None
                         response = await func(
                             origin, content, request.args, *args, **kwargs
                         )
@@ -312,9 +322,9 @@ class BaseFederationServlet:
 
             return response
 
-        return new_func
+        return cast(ServletCallback, new_func)
 
-    def register(self, server):
+    def register(self, server: HttpServer) -> None:
         pattern = re.compile("^" + self.PREFIX + self.PATH + "$")
 
         for method in ("GET", "PUT", "POST"):