asyncutils.context

Contextual configuration system, inspired by the decimal module.

Attributes

all_contextual_consts

A frozenset of all contextual constant names, for use in validating that only valid contextual constants are accessed or modified.

Classes

Context
localcontext	Context manager that temporarily sets the context of the current thread to a modified version of the provided context. Non-reentrant, but reusable with the exact same new_ctx.
nonreusablelocalcontext	Version of localcontext that is not reusable. Use this to avoid subtle bugs, especially since it's not that expensive to instantiate a Context.

Functions

getcontext(→ Context)	Return the current context for the active thread.
setcontext(→ None)	Set the current context to for the active thread to ctx.

Module Contents

class asyncutils.context.Context

An object storing configuration for various functions and patterns in this library, for immutability and performance; that is, not loading

dataclasses for @dataclass, which loads inspect, triggering a cascade of imports.

collections.namedtuple() is also unsuitable for this use case, since it behaves like a sequence.

The order of the fields are kept in alphabetical order of submodule and in each submodule, and new fields may be added in the future.

For consistency, each field is named in all caps with words separated by underscores, and prefixed by the name of the utility it is used in,

followed by a concise description of what it configures.

Tip

If you need to use any of the settings, you can find the documentation under the API reference for the utilities that use that setting.

Note

Refer to config for the factory default values of each setting.

Note

It is possible, but discouraged, to access these fields with attribute names that are not all uppercase.

Note

This is only type annotated as a dataclass for convenience and to avoid even more code duplication than there is now.

__copy__() → Self

Alias for copy().

__eq__(other: object, /) → bool

Two contexts are considered equal if they are of the same type and all of their fields are equal.

__getitem__(name: str, /) → Any

Context’s also behave like mappings.

__setitem__(name: str, value: object, /) → None

Alias for __setattr__().

ascurctx(**k: Any) → nonreusablelocalcontext

Return a non-reusable context manager that sets the context to this context on entry. ctx.ascurctx() is syntactic sugar for nonreusablelocalcontext(ctx)

asdict() → dict[str, Any]

Return a dictionary representing the items within the context.

copy() → Self

Return a shallow copy of the context.

classmethod from_dct(dct: dict[str, Any], /) → Self

Build an instance from the keys of the dictionary.

pprint(

file: asyncutils._internal.types.CanWriteAndFlush[str] = ...,

*,

pp: pprint.PrettyPrinter | None = ...,

incl_newline: bool = ...,

) → None

Pretty print the context to the provided file-like object file with the pprint.PrettyPrinter instance pp, without a trailing newline if incl_newline=False is specified.

replace(/, **k: object) → Self

Return a new instance with the same values as this one besides the keyword arguments.

replace_from_dct(dct: dict[str, Any], /) → Self

Return a new instance with the same values as this one besides the keys of dct.

update(dct: dict[str, Any] = ..., /, **k: object) → None

Update the values of the instance with dct if passed, then the keyword arguments.

ADVANCED_POOL_DEFAULT_MAX_WORKERS: int = Ellipsis

ADVANCED_POOL_DEFAULT_MIN_WORKERS: int = Ellipsis

ADVANCED_POOL_FACTOR: float = Ellipsis

ADVANCED_POOL_THRESHOLD_HI: float = Ellipsis

ADVANCED_POOL_THRESHOLD_LO: float = Ellipsis

ADVANCED_RATE_LIMIT_DEFAULT_TOKENS: float = Ellipsis

AFRIEVALDS_DEFAULT_K: int = Ellipsis

AGING_RWLOCK_DEFAULT_READ_PRIORITY_FACTOR: float = Ellipsis

AGING_RWLOCK_DEFAULT_WRITE_PRIORITY_FACTOR: float = Ellipsis

AITER_TO_GEN_DEFAULT_ALLOW_FUTURES: bool = Ellipsis

AITER_TO_GEN_DEFAULT_STRICT: bool = Ellipsis

AONLINESORTER_DEFAULT_SLOW: bool = Ellipsis

AUNZIP_DEFAULT_MAX_QSIZE: int = Ellipsis

AUNZIP_DEFAULT_PUT_BATCH: int = Ellipsis

BACKGROUND_REFRESH_CACHE_DEFAULT_REFRESH: float = Ellipsis

BACKGROUND_REFRESH_CACHE_DEFAULT_TTL: float = Ellipsis

BATCH_PROCESSOR_DEFAULT_MAX_SIZE: int = Ellipsis

BATCH_PROCESSOR_DEFAULT_MAX_TIME: float = Ellipsis

BENCHMARK_DEFAULT_SEQUENTIAL: bool = Ellipsis

BENCHMARK_DEFAULT_TIMES: int = Ellipsis

BENCHMARK_DEFAULT_WARMUP: int = Ellipsis

BOUNDED_BATCH_PROCESSOR_DEFAULT_BATCH_SIZE: int = Ellipsis

BOUNDED_BATCH_PROCESSOR_DEFAULT_MAX_CONCURRENT: int = Ellipsis

BULKHEAD_DEFAULT_MAX_QUEUE: int = Ellipsis

BULKHEAD_DEFAULT_MAX_REJ: int = Ellipsis

CIRCUIT_BREAKER_DEFAULT_MAX_FAILS: int = Ellipsis

CIRCUIT_BREAKER_DEFAULT_MAX_HALF_OPEN_CALLS: int = Ellipsis

CIRCUIT_BREAKER_DEFAULT_RESET: float = Ellipsis

CONNECTION_POOL_DEFAULT_MAX_LIFE: float = Ellipsis

CONNECTION_POOL_DEFAULT_MAX_SIZE: int = Ellipsis

CONNECTION_POOL_DEFAULT_MIN_SIZE: int = Ellipsis

CONNECTION_POOL_MAINTENANCE_INTERVAL: float = Ellipsis

CONVERT_TO_CORO_ITER_DEFAULT_SKIP_INVALID: bool = Ellipsis

DUAL_CONTEXT_MANAGER_DEFAULT_MAY_CREATE_EXECUTOR: bool = Ellipsis

DUAL_CONTEXT_MANAGER_DEFAULT_STRICT: bool = Ellipsis

DUAL_CONTEXT_MANAGER_DEFAULT_USE_EXISTING_EXECUTOR: bool = Ellipsis

DYNAMIC_BOUNDED_SEMAPHORE_DEFAULT_VALUE: int = Ellipsis

DYNAMIC_THROTTLE_DEFAULT_JITTER: float = Ellipsis

DYNAMIC_THROTTLE_DEFAULT_LBOUND: float = Ellipsis

DYNAMIC_THROTTLE_DEFAULT_LFACTOR: float = Ellipsis

DYNAMIC_THROTTLE_DEFAULT_MAX_RATE: float = Ellipsis

DYNAMIC_THROTTLE_DEFAULT_MIN_RATE: float = Ellipsis

DYNAMIC_THROTTLE_DEFAULT_UBOUND: float = Ellipsis

DYNAMIC_THROTTLE_DEFAULT_UFACTOR: float = Ellipsis

DYNAMIC_THROTTLE_DEFAULT_WINDOW: int = Ellipsis

EVENT_BUS_DEFAULT_MAX_CONCURRENT: int = Ellipsis

EVENT_BUS_PUBLISH_DEFAULT_SAFE: bool = Ellipsis

EVENT_BUS_STREAM_DEFAULT_BUFFER_SIZE: int = Ellipsis

EVENT_BUS_STREAM_DEFAULT_ITEM_TIMEOUT: float | None = Ellipsis

EVENT_BUS_STREAM_DEFAULT_TIMEOUT: float | None = Ellipsis

EVENT_LOOP_BASE_FLAGS: int = Ellipsis

EVENT_WITH_VALUE_DEFAULT_MAX_HIST: int = Ellipsis

EVENT_WITH_VALUE_DEFAULT_RECENT: float = Ellipsis

GATHER_WITH_LIMITED_CONCURRENCY_DEFAULT_MAX_CONCURRENT: int = Ellipsis

ITER_TO_AGEN_DEFAULT_MAY_CREATE_EXECUTOR: bool = Ellipsis

ITER_TO_AGEN_DEFAULT_STRICT: bool = Ellipsis

ITER_TO_AGEN_DEFAULT_USE_EXISTING_EXECUTOR: bool = Ellipsis

LEAKY_BUCKET_ADJMAP: collections.abc.Sequence[tuple[float, tuple[float, float, float, float]]] = Ellipsis

LEAKY_BUCKET_DEFAULT_ACQUIRE_TOKENS: float = Ellipsis

LEAKY_BUCKET_DEFAULT_EXT_CAN_SET_FACTOR: bool = Ellipsis

LEAKY_BUCKET_DEFAULT_MAX_FACTOR: float = Ellipsis

LEAKY_BUCKET_DEFAULT_MIN_FACTOR: float = Ellipsis

LEAKY_BUCKET_DEFAULT_WAIT_FOR_TOKENS_TOKENS: float = Ellipsis

LEAKY_BUCKET_WAIT_FOR_TOKENS_TICK: float = Ellipsis

LINE_PROTOCOL_DEFAULT_BUFFER_SIZE: int = Ellipsis

LOCKSMITH_BASE_DEFAULT_TIMEOUTS: tuple[float | None, float | None, float | None] = Ellipsis

MEMORY_MAPPED_IO_MANAGER_DEFAULT_CHECKSUM_ALG: asyncutils._internal.types.HashAlgorithm = Ellipsis

MEMORY_MAPPED_IO_MANAGER_DEFAULT_MINIMIZE_WRITES: bool = Ellipsis

MERGE_DEFAULT_MAX_QSIZE: int = Ellipsis

OBSERVABLE_DEFAULT_NTIMES_N: int = Ellipsis

PASSWORD_QUEUE_DEFAULT_GET_FROM: str = Ellipsis

PASSWORD_QUEUE_DEFAULT_PUT_FROM: str = Ellipsis

PRIORITY_SEMAPHORE_DEFAULT_VALUE: int = Ellipsis

RENDEZVOUS_MAINTENANCE_INTERVAL: float = Ellipsis

RETRY_DEFAULT_BACKOFF: float = Ellipsis

RETRY_DEFAULT_DELAY: float = Ellipsis

RETRY_DEFAULT_JITTER: float = Ellipsis

RETRY_DEFAULT_MAX_DELAY: float = Ellipsis

RETRY_DEFAULT_TRIES: int = Ellipsis

RWLOCK_DEFAULT_PREFER_WRITERS: bool = Ellipsis

SEMAPHORE_DEFAULT_VALUE: int = Ellipsis

SOCKET_TRANSPORT_LIMITS: tuple[int, int] = Ellipsis

TEE_DEFAULT_MAX_QSIZE: int = Ellipsis

TEE_DEFAULT_PUT_EXC: bool = Ellipsis

TIMER_DEFAULT_PRECISION: int = Ellipsis

TOKEN_BUCKET_DEFAULT_CONSUME_TOKENS: float = Ellipsis

WAIT_FOR_SIGNAL_DEFAULT_SIGNALS: collections.abc.Sequence[int] = Ellipsis

__hash__: ClassVar[None]

Contexts are not hashable since they are mutable.

class asyncutils.context.localcontext(ctx: Context = ..., **k: object)

Context manager that temporarily sets the context of the current thread to a modified version of the provided context. Non-reentrant, but reusable with the exact same new_ctx.

Note that the context of the current thread is to be set to a shallow copy of ctx, defaulting to the current context, with replacements from the keyword arguments.

async __aenter__() → Context

Return the new context after setting it.

async __aexit__(exc_typ: asyncutils._internal.types.ExcType, exc_val: BaseException, exc_tb: types.TracebackType, /) → None

async __aexit__(exc_typ: None, exc_val: None, exc_tb: None, /) → None

Reset the context to the previous.

__enter__() → Context

Return the new context after setting it.

__exit__(exc_typ: asyncutils._internal.types.ExcType, exc_val: BaseException, exc_tb: types.TracebackType, /) → None

__exit__(exc_typ: None, exc_val: None, exc_tb: None, /) → None

Reset the context to the previous.

property new_ctx: Context

The new context to be set on context manager entry.

property saved_ctx: Context

The previous context to be restored on context manager exit.

class asyncutils.context.nonreusablelocalcontext(ctx: Context = ..., **k: object)

Bases: localcontext

Version of localcontext that is not reusable. Use this to avoid subtle bugs, especially since it’s not that expensive to instantiate a Context.

Note that the context of the current thread is to be set to a shallow copy of ctx, defaulting to the current context, with replacements from the keyword arguments.

asyncutils.context.getcontext() → Context

Return the current context for the active thread.

asyncutils.context.setcontext(ctx: Context, /) → None

Set the current context to for the active thread to ctx.

asyncutils.context.all_contextual_consts: frozenset[str]

A frozenset of all contextual constant names, for use in validating that only valid contextual constants are accessed or modified.

Note

These names are not listed by calling dir() on this submodule, since there are so many of them (87 as of now!) and more may be added in the future, and the recommended way to get their values is to query them on the actual context object anyway. However, they are still provided below to facilitate type checking.