diff options
Diffstat (limited to 'synapse/util/caches/deferred_cache.py')
| -rw-r--r-- | synapse/util/caches/deferred_cache.py | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/synapse/util/caches/deferred_cache.py b/synapse/util/caches/deferred_cache.py index 3c4cc093af..377c9a282a 100644 --- a/synapse/util/caches/deferred_cache.py +++ b/synapse/util/caches/deferred_cache.py @@ -22,6 +22,7 @@ from typing import ( Iterable, MutableMapping, Optional, + Sized, TypeVar, Union, cast, @@ -104,7 +105,13 @@ class DeferredCache(Generic[KT, VT]): max_size=max_entries, cache_name=name, cache_type=cache_type, - size_callback=(lambda d: len(d) or 1) if iterable else None, + size_callback=( + (lambda d: len(cast(Sized, d)) or 1) + # Argument 1 to "len" has incompatible type "VT"; expected "Sized" + # We trust that `VT` is `Sized` when `iterable` is `True` + if iterable + else None + ), metrics_collection_callback=metrics_cb, apply_cache_factor_from_config=apply_cache_factor_from_config, prune_unread_entries=prune_unread_entries, |