diff --git a/synapse/util/async_helpers.py b/synapse/util/async_helpers.py
index 60c03a66fd..a9f67dcbac 100644
--- a/synapse/util/async_helpers.py
+++ b/synapse/util/async_helpers.py
@@ -40,7 +40,7 @@ from typing import (
)
import attr
-from typing_extensions import ContextManager
+from typing_extensions import ContextManager, Literal
from twisted.internet import defer
from twisted.internet.defer import CancelledError
@@ -96,6 +96,10 @@ class ObservableDeferred(Generic[_T], AbstractObservableDeferred[_T]):
__slots__ = ["_deferred", "_observers", "_result"]
+ _deferred: "defer.Deferred[_T]"
+ _observers: Union[List["defer.Deferred[_T]"], Tuple[()]]
+ _result: Union[None, Tuple[Literal[True], _T], Tuple[Literal[False], Failure]]
+
def __init__(self, deferred: "defer.Deferred[_T]", consumeErrors: bool = False):
object.__setattr__(self, "_deferred", deferred)
object.__setattr__(self, "_result", None)
@@ -158,12 +162,14 @@ class ObservableDeferred(Generic[_T], AbstractObservableDeferred[_T]):
effect the underlying deferred.
"""
if not self._result:
+ assert isinstance(self._observers, list)
d: "defer.Deferred[_T]" = defer.Deferred()
self._observers.append(d)
return d
+ elif self._result[0]:
+ return defer.succeed(self._result[1])
else:
- success, res = self._result
- return defer.succeed(res) if success else defer.fail(res)
+ return defer.fail(self._result[1])
def observers(self) -> "Collection[defer.Deferred[_T]]":
return self._observers
@@ -175,6 +181,8 @@ class ObservableDeferred(Generic[_T], AbstractObservableDeferred[_T]):
return self._result is not None and self._result[0] is True
def get_result(self) -> Union[_T, Failure]:
+ if self._result is None:
+ raise ValueError(f"{self!r} has no result yet")
return self._result[1]
def __getattr__(self, name: str) -> Any:
|
