Fix up type hints for Twisted 21.7

changelog.d/10490.misc

@@ -0,0 +1 @@
+Fix up type annotations to work with Twisted 21.7.

synapse/http/client.py

@@ -847,7 +847,7 @@ def connectionLost(self, reason: Failure = connectionDone) -> None:
 
 def read_body_with_max_size(
  response: IResponse, stream: ByteWriteable, max_size: Optional[int]
-) -> defer.Deferred:
+) -> "defer.Deferred[int]":
  """
  Read a HTTP response body to a file-object. Optionally enforcing a maximum file size.
 
@@ -862,7 +862,7 @@ def read_body_with_max_size(
  Returns:
  A Deferred which resolves to the length of the read body.
  """
- d = defer.Deferred()
+ d: "defer.Deferred[int]" = defer.Deferred()
 
  # If the Content-Length header gives a size larger than the maximum allowed
  # size, do not bother downloading the body.

synapse/replication/tcp/client.py

@@ -285,7 +285,7 @@ async def wait_for_stream_position(
 
  # Create a new deferred that times out after N seconds, as we don't want
  # to wedge here forever.
- deferred = Deferred()
+ deferred: "Deferred[None]" = Deferred()
  deferred = timeout_deferred(
  deferred, _WAIT_FOR_REPLICATION_TIMEOUT_SECONDS, self._reactor
  )

synapse/util/async_helpers.py

@@ -49,6 +49,8 @@
 
 logger = logging.getLogger(__name__)
 
+_T = TypeVar("_T")
+
 
 class ObservableDeferred:
  """Wraps a deferred object so that we can add observer deferreds. These
@@ -121,7 +123,7 @@ def observe(self) -> defer.Deferred:
  effect the underlying deferred.
  """
  if not self._result:
- d = defer.Deferred()
+ d: "defer.Deferred[Any]" = defer.Deferred()
 
  def remove(r):
  self._observers.discard(d)
@@ -415,7 +417,7 @@ def __init__(self):
  self.key_to_current_writer: Dict[str, defer.Deferred] = {}
 
  async def read(self, key: str) -> ContextManager:
- new_defer = defer.Deferred()
+ new_defer: "defer.Deferred[None]" = defer.Deferred()
 
  curr_readers = self.key_to_current_readers.setdefault(key, set())
  curr_writer = self.key_to_current_writer.get(key, None)
@@ -438,7 +440,7 @@ def _ctx_manager():
  return _ctx_manager()
 
  async def write(self, key: str) -> ContextManager:
- new_defer = defer.Deferred()
+ new_defer: "defer.Deferred[None]" = defer.Deferred()
 
  curr_readers = self.key_to_current_readers.get(key, set())
  curr_writer = self.key_to_current_writer.get(key, None)
@@ -471,10 +473,8 @@ def _ctx_manager():
 
 
 def timeout_deferred(
- deferred: defer.Deferred,
- timeout: float,
- reactor: IReactorTime,
-) -> defer.Deferred:
+ deferred: "defer.Deferred[_T]", timeout: float, reactor: IReactorTime
+) -> "defer.Deferred[_T]":
  """The in built twisted `Deferred.addTimeout` fails to time out deferreds
  that have a canceller that throws exceptions. This method creates a new
  deferred that wraps and times out the given deferred, correctly handling
@@ -497,7 +497,7 @@ def timeout_deferred(
  Returns:
  A new Deferred, which will errback with defer.TimeoutError on timeout.
  """
- new_d = defer.Deferred()
+ new_d: "defer.Deferred[_T]" = defer.Deferred()
 
  timed_out = [False]
 

synapse/util/caches/deferred_cache.py

@@ -16,7 +16,16 @@
 
 import enum
 import threading
-from typing import Callable, Generic, Iterable, MutableMapping, Optional, TypeVar, Union
+from typing import (
+ Callable,
+ Generic,
+ Iterable,
+ MutableMapping,
+ Optional,
+ TypeVar,
+ Union,
+ cast,
+)
 
 from prometheus_client import Gauge
 
@@ -166,7 +175,7 @@ def get_immediate(
  def set(
  self,
  key: KT,
- value: defer.Deferred,
+ value: "defer.Deferred[VT]",
  callback: Optional[Callable[[], None]] = None,
  ) -> defer.Deferred:
  """Adds a new entry to the cache (or updates an existing one).
@@ -214,7 +223,7 @@ def set(
  if value.called:
  result = value.result
  if not isinstance(result, failure.Failure):
- self.cache.set(key, result, callbacks)
+ self.cache.set(key, cast(VT, result), callbacks)
  return value
 
  # otherwise, we'll add an entry to the _pending_deferred_cache for now,

synapse/util/caches/descriptors.py

@@ -413,7 +413,7 @@ def arg_to_cache_key(arg):
  # relevant result for that key.
  deferreds_map = {}
  for arg in missing:
- deferred = defer.Deferred()
+ deferred: "defer.Deferred[Any]" = defer.Deferred()
  deferreds_map[arg] = deferred
  key = arg_to_cache_key(arg)
  cache.set(key, deferred, callback=invalidate_callback)