diff options
| -rw-r--r-- | changelog.d/14663.feature | 1 | ||||
| -rw-r--r-- | synapse/module_api/__init__.py | 40 |
2 files changed, 40 insertions, 1 deletions
diff --git a/changelog.d/14663.feature b/changelog.d/14663.feature new file mode 100644 index 0000000000..b03f3ee54e --- /dev/null +++ b/changelog.d/14663.feature @@ -0,0 +1 @@ +Add a `cached` function to `synapse.module_api` that returns a decorator to cache return values of functions. diff --git a/synapse/module_api/__init__.py b/synapse/module_api/__init__.py index 0092a03c59..6f4a934b05 100644 --- a/synapse/module_api/__init__.py +++ b/synapse/module_api/__init__.py @@ -18,6 +18,7 @@ from typing import ( TYPE_CHECKING, Any, Callable, + Collection, Dict, Generator, Iterable, @@ -126,7 +127,7 @@ from synapse.types import ( from synapse.types.state import StateFilter from synapse.util import Clock from synapse.util.async_helpers import maybe_awaitable -from synapse.util.caches.descriptors import CachedFunction, cached +from synapse.util.caches.descriptors import CachedFunction, cached as _cached from synapse.util.frozenutils import freeze if TYPE_CHECKING: @@ -136,6 +137,7 @@ if TYPE_CHECKING: T = TypeVar("T") P = ParamSpec("P") +F = TypeVar("F", bound=Callable[..., Any]) """ This package defines the 'stable' API which can be used by extension modules which @@ -185,6 +187,42 @@ class UserIpAndAgent: last_seen: int +def cached( + *, + max_entries: int = 1000, + num_args: Optional[int] = None, + uncached_args: Optional[Collection[str]] = None, +) -> Callable[[F], CachedFunction[F]]: + """Returns a decorator that applies a memoizing cache around the function. This + decorator behaves similarly to functools.lru_cache. + + Example: + + @cached() + def foo('a', 'b'): + ... + + Added in Synapse v1.74.0. + + Args: + max_entries: The maximum number of entries in the cache. If the cache is full + and a new entry is added, the least recently accessed entry will be evicted + from the cache. + num_args: The number of positional arguments (excluding `self`) to use as cache + keys. Defaults to all named args of the function. + uncached_args: A list of argument names to not use as the cache key. (`self` is + always ignored.) Cannot be used with num_args. + + Returns: + A decorator that applies a memoizing cache around the function. + """ + return _cached( + max_entries=max_entries, + num_args=num_args, + uncached_args=uncached_args, + ) + + class ModuleApi: """A proxy object that gets passed to various plugin modules so they can register new users etc if necessary. |