mirror of
https://github.com/element-hq/synapse.git
synced 2024-11-23 18:15:53 +03:00
dab88a7b1f
This is so that we can cache it. We also move the sliding sync types to `synapse/types/handlers/sliding_sync.py`. This is mainly in-prep for The only change in behaviour is that `RoomSyncConfig.combine_sync_config(..)` now returns a new room sync config rather than mutating in-place. Reviewable commit-by-commit. --------- Co-authored-by: Eric Eastwood <eric.eastwood@beta.gouv.fr>
381 lines
13 KiB
Python
381 lines
13 KiB
Python
#
|
|
# This file is licensed under the Affero General Public License (AGPL) version 3.
|
|
#
|
|
# Copyright 2020 The Matrix.org Foundation C.I.C.
|
|
# Copyright (C) 2023 New Vector, Ltd
|
|
#
|
|
# This program is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU Affero General Public License as
|
|
# published by the Free Software Foundation, either version 3 of the
|
|
# License, or (at your option) any later version.
|
|
#
|
|
# See the GNU Affero General Public License for more details:
|
|
# <https://www.gnu.org/licenses/agpl-3.0.html>.
|
|
#
|
|
# Originally licensed under the Apache License, Version 2.0:
|
|
# <http://www.apache.org/licenses/LICENSE-2.0>.
|
|
#
|
|
# [This file includes modifications made by New Vector Limited]
|
|
#
|
|
#
|
|
|
|
"""This is a mypy plugin for Synpase to deal with some of the funky typing that
|
|
can crop up, e.g the cache descriptors.
|
|
"""
|
|
|
|
from typing import Callable, Optional, Tuple, Type, Union
|
|
|
|
import mypy.types
|
|
from mypy.erasetype import remove_instance_last_known_values
|
|
from mypy.errorcodes import ErrorCode
|
|
from mypy.nodes import ARG_NAMED_OPT, TempNode, Var
|
|
from mypy.plugin import FunctionSigContext, MethodSigContext, Plugin
|
|
from mypy.typeops import bind_self
|
|
from mypy.types import (
|
|
AnyType,
|
|
CallableType,
|
|
Instance,
|
|
NoneType,
|
|
TupleType,
|
|
TypeAliasType,
|
|
TypeVarType,
|
|
UninhabitedType,
|
|
UnionType,
|
|
)
|
|
|
|
|
|
class SynapsePlugin(Plugin):
|
|
def get_method_signature_hook(
|
|
self, fullname: str
|
|
) -> Optional[Callable[[MethodSigContext], CallableType]]:
|
|
if fullname.startswith(
|
|
(
|
|
"synapse.util.caches.descriptors.CachedFunction.__call__",
|
|
"synapse.util.caches.descriptors._LruCachedFunction.__call__",
|
|
)
|
|
):
|
|
return cached_function_method_signature
|
|
|
|
if fullname in (
|
|
"synapse.util.caches.descriptors._CachedFunctionDescriptor.__call__",
|
|
"synapse.util.caches.descriptors._CachedListFunctionDescriptor.__call__",
|
|
):
|
|
return check_is_cacheable_wrapper
|
|
|
|
return None
|
|
|
|
|
|
def _get_true_return_type(signature: CallableType) -> mypy.types.Type:
|
|
"""
|
|
Get the "final" return type of a callable which might return an Awaitable/Deferred.
|
|
"""
|
|
if isinstance(signature.ret_type, Instance):
|
|
# If a coroutine, unwrap the coroutine's return type.
|
|
if signature.ret_type.type.fullname == "typing.Coroutine":
|
|
return signature.ret_type.args[2]
|
|
|
|
# If an awaitable, unwrap the awaitable's final value.
|
|
elif signature.ret_type.type.fullname == "typing.Awaitable":
|
|
return signature.ret_type.args[0]
|
|
|
|
# If a Deferred, unwrap the Deferred's final value.
|
|
elif signature.ret_type.type.fullname == "twisted.internet.defer.Deferred":
|
|
return signature.ret_type.args[0]
|
|
|
|
# Otherwise, return the raw value of the function.
|
|
return signature.ret_type
|
|
|
|
|
|
def cached_function_method_signature(ctx: MethodSigContext) -> CallableType:
|
|
"""Fixes the `CachedFunction.__call__` signature to be correct.
|
|
|
|
It already has *almost* the correct signature, except:
|
|
|
|
1. the `self` argument needs to be marked as "bound";
|
|
2. any `cache_context` argument should be removed;
|
|
3. an optional keyword argument `on_invalidated` should be added.
|
|
4. Wrap the return type to always be a Deferred.
|
|
"""
|
|
|
|
# 1. Mark this as a bound function signature.
|
|
signature: CallableType = bind_self(ctx.default_signature)
|
|
|
|
# 2. Remove any "cache_context" args.
|
|
#
|
|
# Note: We should be only doing this if `cache_context=True` is set, but if
|
|
# it isn't then the code will raise an exception when its called anyway, so
|
|
# it's not the end of the world.
|
|
context_arg_index = None
|
|
for idx, name in enumerate(signature.arg_names):
|
|
if name == "cache_context":
|
|
context_arg_index = idx
|
|
break
|
|
|
|
arg_types = list(signature.arg_types)
|
|
arg_names = list(signature.arg_names)
|
|
arg_kinds = list(signature.arg_kinds)
|
|
|
|
if context_arg_index:
|
|
arg_types.pop(context_arg_index)
|
|
arg_names.pop(context_arg_index)
|
|
arg_kinds.pop(context_arg_index)
|
|
|
|
# 3. Add an optional "on_invalidate" argument.
|
|
#
|
|
# This is a either
|
|
# - a callable which accepts no input and returns nothing, or
|
|
# - None.
|
|
calltyp = UnionType(
|
|
[
|
|
NoneType(),
|
|
CallableType(
|
|
arg_types=[],
|
|
arg_kinds=[],
|
|
arg_names=[],
|
|
ret_type=NoneType(),
|
|
fallback=ctx.api.named_generic_type("builtins.function", []),
|
|
),
|
|
]
|
|
)
|
|
|
|
arg_types.append(calltyp)
|
|
arg_names.append("on_invalidate")
|
|
arg_kinds.append(ARG_NAMED_OPT) # Arg is an optional kwarg.
|
|
|
|
# 4. Ensure the return type is a Deferred.
|
|
ret_arg = _get_true_return_type(signature)
|
|
|
|
# This should be able to use ctx.api.named_generic_type, but that doesn't seem
|
|
# to find the correct symbol for anything more than 1 module deep.
|
|
#
|
|
# modules is not part of CheckerPluginInterface. The following is a combination
|
|
# of TypeChecker.named_generic_type and TypeChecker.lookup_typeinfo.
|
|
sym = ctx.api.modules["twisted.internet.defer"].names.get("Deferred") # type: ignore[attr-defined]
|
|
ret_type = Instance(sym.node, [remove_instance_last_known_values(ret_arg)])
|
|
|
|
signature = signature.copy_modified(
|
|
arg_types=arg_types,
|
|
arg_names=arg_names,
|
|
arg_kinds=arg_kinds,
|
|
ret_type=ret_type,
|
|
)
|
|
|
|
return signature
|
|
|
|
|
|
def check_is_cacheable_wrapper(ctx: MethodSigContext) -> CallableType:
|
|
"""Asserts that the signature of a method returns a value which can be cached.
|
|
|
|
Makes no changes to the provided method signature.
|
|
"""
|
|
# The true signature, this isn't being modified so this is what will be returned.
|
|
signature: CallableType = ctx.default_signature
|
|
|
|
if not isinstance(ctx.args[0][0], TempNode):
|
|
ctx.api.note("Cached function is not a TempNode?!", ctx.context) # type: ignore[attr-defined]
|
|
return signature
|
|
|
|
orig_sig = ctx.args[0][0].type
|
|
if not isinstance(orig_sig, CallableType):
|
|
ctx.api.fail("Cached 'function' is not a callable", ctx.context)
|
|
return signature
|
|
|
|
check_is_cacheable(orig_sig, ctx)
|
|
|
|
return signature
|
|
|
|
|
|
def check_is_cacheable(
|
|
signature: CallableType,
|
|
ctx: Union[MethodSigContext, FunctionSigContext],
|
|
) -> None:
|
|
"""
|
|
Check if a callable returns a type which can be cached.
|
|
|
|
Args:
|
|
signature: The callable to check.
|
|
ctx: The signature context, used for error reporting.
|
|
"""
|
|
# Unwrap the true return type from the cached function.
|
|
return_type = _get_true_return_type(signature)
|
|
|
|
verbose = ctx.api.options.verbosity >= 1
|
|
# TODO Technically a cachedList only needs immutable values, but forcing them
|
|
# to return Mapping instead of Dict is fine.
|
|
ok, note = is_cacheable(return_type, signature, verbose)
|
|
|
|
if ok:
|
|
message = f"function {signature.name} is @cached, returning {return_type}"
|
|
else:
|
|
message = f"function {signature.name} is @cached, but has mutable return value {return_type}"
|
|
|
|
if note:
|
|
message += f" ({note})"
|
|
message = message.replace("builtins.", "").replace("typing.", "")
|
|
|
|
if ok and note:
|
|
ctx.api.note(message, ctx.context) # type: ignore[attr-defined]
|
|
elif not ok:
|
|
ctx.api.fail(message, ctx.context, code=AT_CACHED_MUTABLE_RETURN)
|
|
|
|
|
|
# Immutable simple values.
|
|
IMMUTABLE_VALUE_TYPES = {
|
|
"builtins.bool",
|
|
"builtins.int",
|
|
"builtins.float",
|
|
"builtins.str",
|
|
"builtins.bytes",
|
|
}
|
|
|
|
# Types defined in Synapse which are known to be immutable.
|
|
IMMUTABLE_CUSTOM_TYPES = {
|
|
"synapse.synapse_rust.acl.ServerAclEvaluator",
|
|
"synapse.synapse_rust.push.FilteredPushRules",
|
|
# This is technically not immutable, but close enough.
|
|
"signedjson.types.VerifyKey",
|
|
"synapse.types.StrCollection",
|
|
}
|
|
|
|
# Immutable containers only if the values are also immutable.
|
|
IMMUTABLE_CONTAINER_TYPES_REQUIRING_IMMUTABLE_ELEMENTS = {
|
|
"builtins.frozenset",
|
|
"builtins.tuple",
|
|
"typing.AbstractSet",
|
|
"typing.Sequence",
|
|
"immutabledict.immutabledict",
|
|
}
|
|
|
|
MUTABLE_CONTAINER_TYPES = {
|
|
"builtins.set",
|
|
"builtins.list",
|
|
"builtins.dict",
|
|
}
|
|
|
|
AT_CACHED_MUTABLE_RETURN = ErrorCode(
|
|
"synapse-@cached-mutable",
|
|
"@cached() should have an immutable return type",
|
|
"General",
|
|
)
|
|
|
|
|
|
def is_cacheable(
|
|
rt: mypy.types.Type, signature: CallableType, verbose: bool
|
|
) -> Tuple[bool, Optional[str]]:
|
|
"""
|
|
Check if a particular type is cachable.
|
|
|
|
A type is cachable if it is immutable; for complex types this recurses to
|
|
check each type parameter.
|
|
|
|
Returns: a 2-tuple (cacheable, message).
|
|
- cachable: False means the type is definitely not cacheable;
|
|
true means anything else.
|
|
- Optional message.
|
|
"""
|
|
|
|
# This should probably be done via a TypeVisitor. Apologies to the reader!
|
|
if isinstance(rt, AnyType):
|
|
return True, ("may be mutable" if verbose else None)
|
|
|
|
elif isinstance(rt, Instance):
|
|
if (
|
|
rt.type.fullname in IMMUTABLE_VALUE_TYPES
|
|
or rt.type.fullname in IMMUTABLE_CUSTOM_TYPES
|
|
):
|
|
# "Simple" types are generally immutable.
|
|
return True, None
|
|
|
|
elif rt.type.fullname == "typing.Mapping":
|
|
# Generally mapping keys are immutable, but they only *have* to be
|
|
# hashable, which doesn't imply immutability. E.g. Mapping[K, V]
|
|
# is cachable iff K and V are cachable.
|
|
return is_cacheable(rt.args[0], signature, verbose) and is_cacheable(
|
|
rt.args[1], signature, verbose
|
|
)
|
|
|
|
elif rt.type.fullname in IMMUTABLE_CONTAINER_TYPES_REQUIRING_IMMUTABLE_ELEMENTS:
|
|
# E.g. Collection[T] is cachable iff T is cachable.
|
|
return is_cacheable(rt.args[0], signature, verbose)
|
|
|
|
elif rt.type.fullname in MUTABLE_CONTAINER_TYPES:
|
|
# Mutable containers are mutable regardless of their underlying type.
|
|
return False, f"container {rt.type.fullname} is mutable"
|
|
|
|
elif "attrs" in rt.type.metadata:
|
|
# attrs classes are only cachable iff it is frozen (immutable itself)
|
|
# and all attributes are cachable.
|
|
frozen = rt.type.metadata["attrs"]["frozen"]
|
|
if frozen:
|
|
for attribute in rt.type.metadata["attrs"]["attributes"]:
|
|
attribute_name = attribute["name"]
|
|
symbol_node = rt.type.names[attribute_name].node
|
|
assert isinstance(symbol_node, Var)
|
|
assert symbol_node.type is not None
|
|
ok, note = is_cacheable(symbol_node.type, signature, verbose)
|
|
if not ok:
|
|
return False, f"non-frozen attrs property: {attribute_name}"
|
|
# All attributes were frozen.
|
|
return True, None
|
|
else:
|
|
return False, "non-frozen attrs class"
|
|
|
|
elif rt.type.is_enum:
|
|
# We assume Enum values are immutable
|
|
return True, None
|
|
else:
|
|
# Ensure we fail for unknown types, these generally means that the
|
|
# above code is not complete.
|
|
return (
|
|
False,
|
|
f"Don't know how to handle {rt.type.fullname} return type instance",
|
|
)
|
|
|
|
elif isinstance(rt, TypeVarType):
|
|
# We consider TypeVars immutable if they are bound to a set of immutable
|
|
# types.
|
|
if rt.values:
|
|
for value in rt.values:
|
|
ok, note = is_cacheable(value, signature, verbose)
|
|
if not ok:
|
|
return False, f"TypeVar bound not cacheable {value}"
|
|
return True, None
|
|
|
|
return False, "TypeVar is unbound"
|
|
|
|
elif isinstance(rt, NoneType):
|
|
# None is cachable.
|
|
return True, None
|
|
|
|
elif isinstance(rt, (TupleType, UnionType)):
|
|
# Tuples and unions are cachable iff all their items are cachable.
|
|
for item in rt.items:
|
|
ok, note = is_cacheable(item, signature, verbose)
|
|
if not ok:
|
|
return False, note
|
|
# This discards notes but that's probably fine
|
|
return True, None
|
|
|
|
elif isinstance(rt, TypeAliasType):
|
|
# For a type alias, check if the underlying real type is cachable.
|
|
return is_cacheable(mypy.types.get_proper_type(rt), signature, verbose)
|
|
|
|
elif isinstance(rt, UninhabitedType) and rt.is_noreturn:
|
|
# There is no return value, just consider it cachable. This is only used
|
|
# in tests.
|
|
return True, None
|
|
|
|
else:
|
|
# Ensure we fail for unknown types, these generally means that the
|
|
# above code is not complete.
|
|
return False, f"Don't know how to handle {type(rt).__qualname__} return type"
|
|
|
|
|
|
def plugin(version: str) -> Type[SynapsePlugin]:
|
|
# This is the entry point of the plugin, and lets us deal with the fact
|
|
# that the mypy plugin interface is *not* stable by looking at the version
|
|
# string.
|
|
#
|
|
# However, since we pin the version of mypy Synapse uses in CI, we don't
|
|
# really care.
|
|
return SynapsePlugin
|