diff --git a/synapse/util/caches/descriptors.py b/synapse/util/caches/descriptors.py
index cd48262420..98b34f2223 100644
--- a/synapse/util/caches/descriptors.py
+++ b/synapse/util/caches/descriptors.py
@@ -18,13 +18,10 @@ import functools
import inspect
import logging
import threading
-from typing import Any, Tuple, Union, cast
+from typing import Any, Callable, Generic, Optional, Tuple, TypeVar, Union, cast
from weakref import WeakValueDictionary
-from six import itervalues
-
from prometheus_client import Gauge
-from typing_extensions import Protocol
from twisted.internet import defer
@@ -40,8 +37,10 @@ logger = logging.getLogger(__name__)
CacheKey = Union[Tuple, Any]
+F = TypeVar("F", bound=Callable[..., Any])
+
-class _CachedFunction(Protocol):
+class _CachedFunction(Generic[F]):
invalidate = None # type: Any
invalidate_all = None # type: Any
invalidate_many = None # type: Any
@@ -49,8 +48,11 @@ class _CachedFunction(Protocol):
cache = None # type: Any
num_args = None # type: Any
- def __name__(self):
- ...
+ __name__ = None # type: str
+
+ # Note: This function signature is actually fiddled with by the synapse mypy
+ # plugin to a) make it a bound method, and b) remove any `cache_context` arg.
+ __call__ = None # type: F
cache_pending_metric = Gauge(
@@ -62,7 +64,7 @@ cache_pending_metric = Gauge(
_CacheSentinel = object()
-class CacheEntry(object):
+class CacheEntry:
__slots__ = ["deferred", "callbacks", "invalidated"]
def __init__(self, deferred, callbacks):
@@ -78,7 +80,7 @@ class CacheEntry(object):
self.callbacks.clear()
-class Cache(object):
+class Cache:
__slots__ = (
"cache",
"name",
@@ -125,7 +127,7 @@ class Cache(object):
self.name = name
self.keylen = keylen
- self.thread = None
+ self.thread = None # type: Optional[threading.Thread]
self.metrics = register_cache(
"cache",
name,
@@ -194,7 +196,7 @@ class Cache(object):
callbacks = [callback] if callback else []
self.check_thread()
observable = ObservableDeferred(value, consumeErrors=True)
- observer = defer.maybeDeferred(observable.observe)
+ observer = observable.observe()
entry = CacheEntry(deferred=observable, callbacks=callbacks)
existing_entry = self._pending_deferred_cache.pop(key, None)
@@ -281,22 +283,15 @@ class Cache(object):
def invalidate_all(self):
self.check_thread()
self.cache.clear()
- for entry in itervalues(self._pending_deferred_cache):
+ for entry in self._pending_deferred_cache.values():
entry.invalidate()
self._pending_deferred_cache.clear()
-class _CacheDescriptorBase(object):
- def __init__(
- self, orig: _CachedFunction, num_args, inlineCallbacks, cache_context=False
- ):
+class _CacheDescriptorBase:
+ def __init__(self, orig: _CachedFunction, num_args, cache_context=False):
self.orig = orig
- if inlineCallbacks:
- self.function_to_call = defer.inlineCallbacks(orig)
- else:
- self.function_to_call = orig
-
arg_spec = inspect.getfullargspec(orig)
all_args = arg_spec.args
@@ -366,7 +361,7 @@ class CacheDescriptor(_CacheDescriptorBase):
invalidated) by adding a special "cache_context" argument to the function
and passing that as a kwarg to all caches called. For example::
- @cachedInlineCallbacks(cache_context=True)
+ @cached(cache_context=True)
def foo(self, key, cache_context):
r1 = yield self.bar1(key, on_invalidate=cache_context.invalidate)
r2 = yield self.bar2(key, on_invalidate=cache_context.invalidate)
@@ -384,17 +379,11 @@ class CacheDescriptor(_CacheDescriptorBase):
max_entries=1000,
num_args=None,
tree=False,
- inlineCallbacks=False,
cache_context=False,
iterable=False,
):
- super(CacheDescriptor, self).__init__(
- orig,
- num_args=num_args,
- inlineCallbacks=inlineCallbacks,
- cache_context=cache_context,
- )
+ super().__init__(orig, num_args=num_args, cache_context=cache_context)
self.max_entries = max_entries
self.tree = tree
@@ -467,9 +456,7 @@ class CacheDescriptor(_CacheDescriptorBase):
observer = defer.succeed(cached_result_d)
except KeyError:
- ret = defer.maybeDeferred(
- preserve_fn(self.function_to_call), obj, *args, **kwargs
- )
+ ret = defer.maybeDeferred(preserve_fn(self.orig), obj, *args, **kwargs)
def onErr(f):
cache.invalidate(cache_key)
@@ -512,23 +499,17 @@ class CacheListDescriptor(_CacheDescriptorBase):
of results.
"""
- def __init__(
- self, orig, cached_method_name, list_name, num_args=None, inlineCallbacks=False
- ):
+ def __init__(self, orig, cached_method_name, list_name, num_args=None):
"""
Args:
orig (function)
- cached_method_name (str): The name of the chached method.
+ cached_method_name (str): The name of the cached method.
list_name (str): Name of the argument which is the bulk lookup list
num_args (int): number of positional arguments (excluding ``self``,
but including list_name) to use as cache keys. Defaults to all
named args of the function.
- inlineCallbacks (bool): Whether orig is a generator that should
- be wrapped by defer.inlineCallbacks
"""
- super(CacheListDescriptor, self).__init__(
- orig, num_args=num_args, inlineCallbacks=inlineCallbacks
- )
+ super().__init__(orig, num_args=num_args)
self.list_name = list_name
@@ -633,7 +614,7 @@ class CacheListDescriptor(_CacheDescriptorBase):
cached_defers.append(
defer.maybeDeferred(
- preserve_fn(self.function_to_call), **args_to_call
+ preserve_fn(self.orig), **args_to_call
).addCallbacks(complete_all, errback)
)
@@ -685,9 +666,13 @@ class _CacheContext:
def cached(
- max_entries=1000, num_args=None, tree=False, cache_context=False, iterable=False
-):
- return lambda orig: CacheDescriptor(
+ max_entries: int = 1000,
+ num_args: Optional[int] = None,
+ tree: bool = False,
+ cache_context: bool = False,
+ iterable: bool = False,
+) -> Callable[[F], _CachedFunction[F]]:
+ func = lambda orig: CacheDescriptor(
orig,
max_entries=max_entries,
num_args=num_args,
@@ -696,22 +681,12 @@ def cached(
iterable=iterable,
)
-
-def cachedInlineCallbacks(
- max_entries=1000, num_args=None, tree=False, cache_context=False, iterable=False
-):
- return lambda orig: CacheDescriptor(
- orig,
- max_entries=max_entries,
- num_args=num_args,
- tree=tree,
- inlineCallbacks=True,
- cache_context=cache_context,
- iterable=iterable,
- )
+ return cast(Callable[[F], _CachedFunction[F]], func)
-def cachedList(cached_method_name, list_name, num_args=None, inlineCallbacks=False):
+def cachedList(
+ cached_method_name: str, list_name: str, num_args: Optional[int] = None
+) -> Callable[[F], _CachedFunction[F]]:
"""Creates a descriptor that wraps a function in a `CacheListDescriptor`.
Used to do batch lookups for an already created cache. A single argument
@@ -721,18 +696,16 @@ def cachedList(cached_method_name, list_name, num_args=None, inlineCallbacks=Fal
cache.
Args:
- cached_method_name (str): The name of the single-item lookup method.
+ cached_method_name: The name of the single-item lookup method.
This is only used to find the cache to use.
- list_name (str): The name of the argument that is the list to use to
+ list_name: The name of the argument that is the list to use to
do batch lookups in the cache.
- num_args (int): Number of arguments to use as the key in the cache
+ num_args: Number of arguments to use as the key in the cache
(including list_name). Defaults to all named parameters.
- inlineCallbacks (bool): Should the function be wrapped in an
- `defer.inlineCallbacks`?
Example:
- class Example(object):
+ class Example:
@cached(num_args=2)
def do_something(self, first_arg):
...
@@ -741,10 +714,11 @@ def cachedList(cached_method_name, list_name, num_args=None, inlineCallbacks=Fal
def batch_do_something(self, first_arg, second_args):
...
"""
- return lambda orig: CacheListDescriptor(
+ func = lambda orig: CacheListDescriptor(
orig,
cached_method_name=cached_method_name,
list_name=list_name,
num_args=num_args,
- inlineCallbacks=inlineCallbacks,
)
+
+ return cast(Callable[[F], _CachedFunction[F]], func)
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