diff options
Diffstat (limited to 'venv/lib/python3.11/site-packages/anyio/lowlevel.py')
-rw-r--r-- | venv/lib/python3.11/site-packages/anyio/lowlevel.py | 163 |
1 files changed, 0 insertions, 163 deletions
diff --git a/venv/lib/python3.11/site-packages/anyio/lowlevel.py b/venv/lib/python3.11/site-packages/anyio/lowlevel.py deleted file mode 100644 index a9e10f4..0000000 --- a/venv/lib/python3.11/site-packages/anyio/lowlevel.py +++ /dev/null @@ -1,163 +0,0 @@ -from __future__ import annotations - -import enum -from dataclasses import dataclass -from typing import Any, Generic, Literal, TypeVar, overload -from weakref import WeakKeyDictionary - -from ._core._eventloop import get_async_backend - -T = TypeVar("T") -D = TypeVar("D") - - -async def checkpoint() -> None: - """ - Check for cancellation and allow the scheduler to switch to another task. - - Equivalent to (but more efficient than):: - - await checkpoint_if_cancelled() - await cancel_shielded_checkpoint() - - - .. versionadded:: 3.0 - - """ - await get_async_backend().checkpoint() - - -async def checkpoint_if_cancelled() -> None: - """ - Enter a checkpoint if the enclosing cancel scope has been cancelled. - - This does not allow the scheduler to switch to a different task. - - .. versionadded:: 3.0 - - """ - await get_async_backend().checkpoint_if_cancelled() - - -async def cancel_shielded_checkpoint() -> None: - """ - Allow the scheduler to switch to another task but without checking for cancellation. - - Equivalent to (but potentially more efficient than):: - - with CancelScope(shield=True): - await checkpoint() - - - .. versionadded:: 3.0 - - """ - await get_async_backend().cancel_shielded_checkpoint() - - -def current_token() -> object: - """ - Return a backend specific token object that can be used to get back to the event - loop. - - """ - return get_async_backend().current_token() - - -_run_vars: WeakKeyDictionary[Any, dict[str, Any]] = WeakKeyDictionary() -_token_wrappers: dict[Any, _TokenWrapper] = {} - - -@dataclass(frozen=True) -class _TokenWrapper: - __slots__ = "_token", "__weakref__" - _token: object - - -class _NoValueSet(enum.Enum): - NO_VALUE_SET = enum.auto() - - -class RunvarToken(Generic[T]): - __slots__ = "_var", "_value", "_redeemed" - - def __init__(self, var: RunVar[T], value: T | Literal[_NoValueSet.NO_VALUE_SET]): - self._var = var - self._value: T | Literal[_NoValueSet.NO_VALUE_SET] = value - self._redeemed = False - - -class RunVar(Generic[T]): - """ - Like a :class:`~contextvars.ContextVar`, except scoped to the running event loop. - """ - - __slots__ = "_name", "_default" - - NO_VALUE_SET: Literal[_NoValueSet.NO_VALUE_SET] = _NoValueSet.NO_VALUE_SET - - _token_wrappers: set[_TokenWrapper] = set() - - def __init__( - self, name: str, default: T | Literal[_NoValueSet.NO_VALUE_SET] = NO_VALUE_SET - ): - self._name = name - self._default = default - - @property - def _current_vars(self) -> dict[str, T]: - token = current_token() - try: - return _run_vars[token] - except KeyError: - run_vars = _run_vars[token] = {} - return run_vars - - @overload - def get(self, default: D) -> T | D: - ... - - @overload - def get(self) -> T: - ... - - def get( - self, default: D | Literal[_NoValueSet.NO_VALUE_SET] = NO_VALUE_SET - ) -> T | D: - try: - return self._current_vars[self._name] - except KeyError: - if default is not RunVar.NO_VALUE_SET: - return default - elif self._default is not RunVar.NO_VALUE_SET: - return self._default - - raise LookupError( - f'Run variable "{self._name}" has no value and no default set' - ) - - def set(self, value: T) -> RunvarToken[T]: - current_vars = self._current_vars - token = RunvarToken(self, current_vars.get(self._name, RunVar.NO_VALUE_SET)) - current_vars[self._name] = value - return token - - def reset(self, token: RunvarToken[T]) -> None: - if token._var is not self: - raise ValueError("This token does not belong to this RunVar") - - if token._redeemed: - raise ValueError("This token has already been used") - - if token._value is _NoValueSet.NO_VALUE_SET: - try: - del self._current_vars[self._name] - except KeyError: - pass - else: - self._current_vars[self._name] = token._value - - token._redeemed = True - - def __repr__(self) -> str: - return f"<RunVar name={self._name!r}>" |