Add types to synapse.util. (#10601)

synapse/util/ratelimitutils.py

@@ -15,33 +15,36 @@
 import collections
 import contextlib
 import logging
+import typing
+from typing import Any, DefaultDict, Iterator, List, Set
 
 from twisted.internet import defer
 
 from synapse.api.errors import LimitExceededError
+from synapse.config.ratelimiting import FederationRateLimitConfig
 from synapse.logging.context import (
     PreserveLoggingContext,
     make_deferred_yieldable,
     run_in_background,
 )
+from synapse.util import Clock
+
+if typing.TYPE_CHECKING:
+    from contextlib import _GeneratorContextManager
 
 logger = logging.getLogger(__name__)
 
 
 class FederationRateLimiter:
-    def __init__(self, clock, config):
-        """
-        Args:
-            clock (Clock)
-            config (FederationRateLimitConfig)
-        """
-
-        def new_limiter():
+    def __init__(self, clock: Clock, config: FederationRateLimitConfig):
+        def new_limiter() -> "_PerHostRatelimiter":
             return _PerHostRatelimiter(clock=clock, config=config)
 
-        self.ratelimiters = collections.defaultdict(new_limiter)
+        self.ratelimiters: DefaultDict[
+            str, "_PerHostRatelimiter"
+        ] = collections.defaultdict(new_limiter)
 
-    def ratelimit(self, host):
+    def ratelimit(self, host: str) -> "_GeneratorContextManager[defer.Deferred[None]]":
         """Used to ratelimit an incoming request from a given host
 
         Example usage:
@@ -60,11 +63,11 @@ class FederationRateLimiter:
 
 
 class _PerHostRatelimiter:
-    def __init__(self, clock, config):
+    def __init__(self, clock: Clock, config: FederationRateLimitConfig):
         """
         Args:
-            clock (Clock)
-            config (FederationRateLimitConfig)
+            clock
+            config
         """
         self.clock = clock
 
@@ -75,21 +78,23 @@ class _PerHostRatelimiter:
         self.concurrent_requests = config.concurrent
 
         # request_id objects for requests which have been slept
-        self.sleeping_requests = set()
+        self.sleeping_requests: Set[object] = set()
 
         # map from request_id object to Deferred for requests which are ready
         # for processing but have been queued
-        self.ready_request_queue = collections.OrderedDict()
+        self.ready_request_queue: collections.OrderedDict[
+            object, defer.Deferred[None]
+        ] = collections.OrderedDict()
 
         # request id objects for requests which are in progress
-        self.current_processing = set()
+        self.current_processing: Set[object] = set()
 
         # times at which we have recently (within the last window_size ms)
         # received requests.
-        self.request_times = []
+        self.request_times: List[int] = []
 
     @contextlib.contextmanager
-    def ratelimit(self):
+    def ratelimit(self) -> "Iterator[defer.Deferred[None]]":
         # `contextlib.contextmanager` takes a generator and turns it into a
         # context manager. The generator should only yield once with a value
         # to be returned by manager.
@@ -102,7 +107,7 @@ class _PerHostRatelimiter:
         finally:
             self._on_exit(request_id)
 
-    def _on_enter(self, request_id):
+    def _on_enter(self, request_id: object) -> "defer.Deferred[None]":
         time_now = self.clock.time_msec()
 
         # remove any entries from request_times which aren't within the window
@@ -120,9 +125,9 @@ class _PerHostRatelimiter:
 
         self.request_times.append(time_now)
 
-        def queue_request():
+        def queue_request() -> "defer.Deferred[None]":
             if len(self.current_processing) >= self.concurrent_requests:
-                queue_defer = defer.Deferred()
+                queue_defer: defer.Deferred[None] = defer.Deferred()
                 self.ready_request_queue[request_id] = queue_defer
                 logger.info(
                     "Ratelimiter: queueing request (queue now %i items)",
@@ -145,7 +150,7 @@ class _PerHostRatelimiter:
 
             self.sleeping_requests.add(request_id)
 
-            def on_wait_finished(_):
+            def on_wait_finished(_: Any) -> "defer.Deferred[None]":
                 logger.debug("Ratelimit [%s]: Finished sleeping", id(request_id))
                 self.sleeping_requests.discard(request_id)
                 queue_defer = queue_request()
@@ -155,19 +160,19 @@ class _PerHostRatelimiter:
         else:
             ret_defer = queue_request()
 
-        def on_start(r):
+        def on_start(r: object) -> object:
             logger.debug("Ratelimit [%s]: Processing req", id(request_id))
             self.current_processing.add(request_id)
             return r
 
-        def on_err(r):
+        def on_err(r: object) -> object:
             # XXX: why is this necessary? this is called before we start
             # processing the request so why would the request be in
             # current_processing?
             self.current_processing.discard(request_id)
             return r
 
-        def on_both(r):
+        def on_both(r: object) -> object:
             # Ensure that we've properly cleaned up.
             self.sleeping_requests.discard(request_id)
             self.ready_request_queue.pop(request_id, None)
@@ -177,7 +182,7 @@ class _PerHostRatelimiter:
         ret_defer.addBoth(on_both)
         return make_deferred_yieldable(ret_defer)
 
-    def _on_exit(self, request_id):
+    def _on_exit(self, request_id: object) -> None:
         logger.debug("Ratelimit [%s]: Processed req", id(request_id))
         self.current_processing.discard(request_id)
         try: