Загрузить файлы в «venv/Lib/site-packages/anyio»

venv/Lib/site-packages/anyio/__init__.py

@@ -0,0 +1,115 @@
+from __future__ import annotations
+
+from ._core._contextmanagers import AsyncContextManagerMixin as AsyncContextManagerMixin
+from ._core._contextmanagers import ContextManagerMixin as ContextManagerMixin
+from ._core._eventloop import current_time as current_time
+from ._core._eventloop import get_all_backends as get_all_backends
+from ._core._eventloop import get_available_backends as get_available_backends
+from ._core._eventloop import get_cancelled_exc_class as get_cancelled_exc_class
+from ._core._eventloop import run as run
+from ._core._eventloop import sleep as sleep
+from ._core._eventloop import sleep_forever as sleep_forever
+from ._core._eventloop import sleep_until as sleep_until
+from ._core._exceptions import BrokenResourceError as BrokenResourceError
+from ._core._exceptions import BrokenWorkerInterpreter as BrokenWorkerInterpreter
+from ._core._exceptions import BrokenWorkerProcess as BrokenWorkerProcess
+from ._core._exceptions import BusyResourceError as BusyResourceError
+from ._core._exceptions import ClosedResourceError as ClosedResourceError
+from ._core._exceptions import ConnectionFailed as ConnectionFailed
+from ._core._exceptions import DelimiterNotFound as DelimiterNotFound
+from ._core._exceptions import EndOfStream as EndOfStream
+from ._core._exceptions import IncompleteRead as IncompleteRead
+from ._core._exceptions import NoEventLoopError as NoEventLoopError
+from ._core._exceptions import RunFinishedError as RunFinishedError
+from ._core._exceptions import TaskCancelled as TaskCancelled
+from ._core._exceptions import TaskFailed as TaskFailed
+from ._core._exceptions import TaskNotFinished as TaskNotFinished
+from ._core._exceptions import TypedAttributeLookupError as TypedAttributeLookupError
+from ._core._exceptions import WouldBlock as WouldBlock
+from ._core._fileio import AsyncFile as AsyncFile
+from ._core._fileio import Path as Path
+from ._core._fileio import open_file as open_file
+from ._core._fileio import wrap_file as wrap_file
+from ._core._resources import aclose_forcefully as aclose_forcefully
+from ._core._signals import open_signal_receiver as open_signal_receiver
+from ._core._sockets import TCPConnectable as TCPConnectable
+from ._core._sockets import UNIXConnectable as UNIXConnectable
+from ._core._sockets import as_connectable as as_connectable
+from ._core._sockets import connect_tcp as connect_tcp
+from ._core._sockets import connect_unix as connect_unix
+from ._core._sockets import create_connected_udp_socket as create_connected_udp_socket
+from ._core._sockets import (
+    create_connected_unix_datagram_socket as create_connected_unix_datagram_socket,
+)
+from ._core._sockets import create_tcp_listener as create_tcp_listener
+from ._core._sockets import create_udp_socket as create_udp_socket
+from ._core._sockets import create_unix_datagram_socket as create_unix_datagram_socket
+from ._core._sockets import create_unix_listener as create_unix_listener
+from ._core._sockets import getaddrinfo as getaddrinfo
+from ._core._sockets import getnameinfo as getnameinfo
+from ._core._sockets import notify_closing as notify_closing
+from ._core._sockets import wait_readable as wait_readable
+from ._core._sockets import wait_socket_readable as wait_socket_readable
+from ._core._sockets import wait_socket_writable as wait_socket_writable
+from ._core._sockets import wait_writable as wait_writable
+from ._core._streams import create_memory_object_stream as create_memory_object_stream
+from ._core._subprocesses import open_process as open_process
+from ._core._subprocesses import run_process as run_process
+from ._core._synchronization import CapacityLimiter as CapacityLimiter
+from ._core._synchronization import (
+    CapacityLimiterStatistics as CapacityLimiterStatistics,
+)
+from ._core._synchronization import Condition as Condition
+from ._core._synchronization import ConditionStatistics as ConditionStatistics
+from ._core._synchronization import Event as Event
+from ._core._synchronization import EventStatistics as EventStatistics
+from ._core._synchronization import Lock as Lock
+from ._core._synchronization import LockStatistics as LockStatistics
+from ._core._synchronization import ResourceGuard as ResourceGuard
+from ._core._synchronization import Semaphore as Semaphore
+from ._core._synchronization import SemaphoreStatistics as SemaphoreStatistics
+from ._core._tasks import TASK_STATUS_IGNORED as TASK_STATUS_IGNORED
+from ._core._tasks import CancelScope as CancelScope
+from ._core._tasks import TaskHandle as TaskHandle
+from ._core._tasks import create_task_group as create_task_group
+from ._core._tasks import current_effective_deadline as current_effective_deadline
+from ._core._tasks import fail_after as fail_after
+from ._core._tasks import move_on_after as move_on_after
+from ._core._tempfile import NamedTemporaryFile as NamedTemporaryFile
+from ._core._tempfile import SpooledTemporaryFile as SpooledTemporaryFile
+from ._core._tempfile import TemporaryDirectory as TemporaryDirectory
+from ._core._tempfile import TemporaryFile as TemporaryFile
+from ._core._tempfile import gettempdir as gettempdir
+from ._core._tempfile import gettempdirb as gettempdirb
+from ._core._tempfile import mkdtemp as mkdtemp
+from ._core._tempfile import mkstemp as mkstemp
+from ._core._testing import TaskInfo as TaskInfo
+from ._core._testing import get_current_task as get_current_task
+from ._core._testing import get_running_tasks as get_running_tasks
+from ._core._testing import wait_all_tasks_blocked as wait_all_tasks_blocked
+from ._core._typedattr import TypedAttributeProvider as TypedAttributeProvider
+from ._core._typedattr import TypedAttributeSet as TypedAttributeSet
+from ._core._typedattr import typed_attribute as typed_attribute
+
+# Re-export imports so they look like they live directly in this package
+for __value in list(locals().values()):
+    if getattr(__value, "__module__", "").startswith("anyio."):
+        __value.__module__ = __name__
+
+
+del __value
+
+
+def __getattr__(attr: str) -> type[BrokenWorkerInterpreter]:
+    """Support deprecated aliases."""
+    if attr == "BrokenWorkerIntepreter":
+        import warnings
+
+        warnings.warn(
+            "The 'BrokenWorkerIntepreter' alias is deprecated, use 'BrokenWorkerInterpreter' instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return BrokenWorkerInterpreter
+
+    raise AttributeError(f"module {__name__!r} has no attribute {attr!r}")

venv/Lib/site-packages/anyio/from_thread.py

@@ -0,0 +1,582 @@
+from __future__ import annotations
+
+__all__ = (
+    "BlockingPortal",
+    "BlockingPortalProvider",
+    "check_cancelled",
+    "run",
+    "run_sync",
+    "start_blocking_portal",
+)
+
+import sys
+from collections.abc import Awaitable, Callable, Coroutine, Generator
+from concurrent.futures import Future
+from contextlib import (
+    AbstractAsyncContextManager,
+    AbstractContextManager,
+    contextmanager,
+)
+from dataclasses import dataclass, field
+from functools import partial
+from inspect import isawaitable
+from threading import Lock, Thread, current_thread, get_ident
+from types import TracebackType
+from typing import (
+    Any,
+    Generic,
+    TypeVar,
+    cast,
+    overload,
+)
+
+from ._core._eventloop import (
+    get_cancelled_exc_class,
+    threadlocals,
+)
+from ._core._eventloop import run as run_eventloop
+from ._core._exceptions import NoEventLoopError
+from ._core._synchronization import Event
+from ._core._tasks import CancelScope, create_task_group
+from .abc._tasks import TaskStatus
+from .lowlevel import EventLoopToken, current_token
+
+if sys.version_info >= (3, 11):
+    from typing import TypeVarTuple, Unpack
+else:
+    from typing_extensions import TypeVarTuple, Unpack
+
+T_Retval = TypeVar("T_Retval")
+T_co = TypeVar("T_co", covariant=True)
+PosArgsT = TypeVarTuple("PosArgsT")
+
+
+def _token_or_error(token: EventLoopToken | None) -> EventLoopToken:
+    if token is not None:
+        return token
+
+    try:
+        return threadlocals.current_token
+    except AttributeError:
+        raise NoEventLoopError(
+            "Not running inside an AnyIO worker thread, and no event loop token was "
+            "provided"
+        ) from None
+
+
+def run(
+    func: Callable[[Unpack[PosArgsT]], Coroutine[Any, Any, T_co]],
+    *args: Unpack[PosArgsT],
+    token: EventLoopToken | None = None,
+) -> T_co:
+    """
+    Call a coroutine function from a worker thread.
+
+    :param func: a coroutine function
+    :param args: positional arguments for the callable
+    :param token: an event loop token to use to get back to the event loop thread
+        (required if calling this function from outside an AnyIO worker thread)
+    :return: the return value of the coroutine function
+    :raises MissingTokenError: if no token was provided and called from outside an
+        AnyIO worker thread
+    :raises RunFinishedError: if the event loop tied to ``token`` is no longer running
+
+    .. versionchanged:: 4.11.0
+        Added the ``token`` parameter.
+
+    """
+    explicit_token = token is not None
+    token = _token_or_error(token)
+    return token.backend_class.run_async_from_thread(
+        func, args, token=token.native_token if explicit_token else None
+    )
+
+
+def run_sync(
+    func: Callable[[Unpack[PosArgsT]], T_Retval],
+    *args: Unpack[PosArgsT],
+    token: EventLoopToken | None = None,
+) -> T_Retval:
+    """
+    Call a function in the event loop thread from a worker thread.
+
+    :param func: a callable
+    :param args: positional arguments for the callable
+    :param token: an event loop token to use to get back to the event loop thread
+        (required if calling this function from outside an AnyIO worker thread)
+    :return: the return value of the callable
+    :raises MissingTokenError: if no token was provided and called from outside an
+        AnyIO worker thread
+    :raises RunFinishedError: if the event loop tied to ``token`` is no longer running
+
+    .. versionchanged:: 4.11.0
+        Added the ``token`` parameter.
+
+    """
+    explicit_token = token is not None
+    token = _token_or_error(token)
+    return token.backend_class.run_sync_from_thread(
+        func, args, token=token.native_token if explicit_token else None
+    )
+
+
+class _BlockingAsyncContextManager(Generic[T_co], AbstractContextManager):
+    _enter_future: Future[T_co]
+    _exit_future: Future[bool | None]
+    _exit_event: Event
+    _exit_exc_info: tuple[
+        type[BaseException] | None, BaseException | None, TracebackType | None
+    ] = (None, None, None)
+
+    def __init__(
+        self, async_cm: AbstractAsyncContextManager[T_co], portal: BlockingPortal
+    ):
+        self._async_cm = async_cm
+        self._portal = portal
+
+    async def run_async_cm(self) -> bool | None:
+        try:
+            self._exit_event = Event()
+            value = await self._async_cm.__aenter__()
+        except BaseException as exc:
+            self._enter_future.set_exception(exc)
+            raise
+        else:
+            self._enter_future.set_result(value)
+
+        try:
+            # Wait for the sync context manager to exit.
+            # This next statement can raise `get_cancelled_exc_class()` if
+            # something went wrong in a task group in this async context
+            # manager.
+            await self._exit_event.wait()
+        finally:
+            # In case of cancellation, it could be that we end up here before
+            # `_BlockingAsyncContextManager.__exit__` is called, and an
+            # `_exit_exc_info` has been set.
+            result = await self._async_cm.__aexit__(*self._exit_exc_info)
+
+        return result
+
+    def __enter__(self) -> T_co:
+        self._enter_future = Future()
+        self._exit_future = self._portal.start_task_soon(self.run_async_cm)
+        return self._enter_future.result()
+
+    def __exit__(
+        self,
+        __exc_type: type[BaseException] | None,
+        __exc_value: BaseException | None,
+        __traceback: TracebackType | None,
+    ) -> bool | None:
+        self._exit_exc_info = __exc_type, __exc_value, __traceback
+        self._portal.call(self._exit_event.set)
+        return self._exit_future.result()
+
+
+class _BlockingPortalTaskStatus(TaskStatus):
+    def __init__(self, future: Future):
+        self._future = future
+
+    def started(self, value: object = None) -> None:
+        self._future.set_result(value)
+
+
+class BlockingPortal:
+    """
+    An object that lets external threads run code in an asynchronous event loop.
+
+    :raises NoEventLoopError: if no supported asynchronous event loop is running in the
+        current thread
+    """
+
+    def __init__(self) -> None:
+        self._token = current_token()
+        self._event_loop_thread_id: int | None = get_ident()
+        self._stop_event = Event()
+        self._task_group = create_task_group()
+
+    async def __aenter__(self) -> BlockingPortal:
+        await self._task_group.__aenter__()
+        return self
+
+    async def __aexit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
+    ) -> bool:
+        await self.stop()
+        return await self._task_group.__aexit__(exc_type, exc_val, exc_tb)
+
+    def _check_running(self) -> None:
+        if self._event_loop_thread_id is None:
+            raise RuntimeError("This portal is not running")
+        if self._event_loop_thread_id == get_ident():
+            raise RuntimeError(
+                "This method cannot be called from the event loop thread"
+            )
+
+    async def sleep_until_stopped(self) -> None:
+        """Sleep until :meth:`stop` is called."""
+        await self._stop_event.wait()
+
+    async def stop(self, cancel_remaining: bool = False) -> None:
+        """
+        Signal the portal to shut down.
+
+        This marks the portal as no longer accepting new calls and exits from
+        :meth:`sleep_until_stopped`.
+
+        :param cancel_remaining: ``True`` to cancel all the remaining tasks, ``False``
+            to let them finish before returning
+
+        """
+        self._event_loop_thread_id = None
+        self._stop_event.set()
+        if cancel_remaining:
+            self._task_group.cancel_scope.cancel("the blocking portal is shutting down")
+
+    async def _call_func(
+        self,
+        func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval] | T_Retval],
+        args: tuple[Unpack[PosArgsT]],
+        kwargs: dict[str, Any],
+        future: Future[T_Retval],
+    ) -> None:
+        event_loop_thread_id = self._event_loop_thread_id
+
+        def callback(f: Future[T_Retval]) -> None:
+            if f.cancelled():
+                if event_loop_thread_id == get_ident():
+                    scope.cancel("the future was cancelled")
+                elif event_loop_thread_id is not None:
+                    run_sync(
+                        scope.cancel, "the future was cancelled", token=self._token
+                    )
+
+        try:
+            retval_or_awaitable = func(*args, **kwargs)
+            if isawaitable(retval_or_awaitable):
+                with CancelScope() as scope:
+                    future.add_done_callback(callback)
+                    retval = await retval_or_awaitable
+            else:
+                retval = retval_or_awaitable
+        except get_cancelled_exc_class():
+            future.cancel()
+            future.set_running_or_notify_cancel()
+        except BaseException as exc:
+            if not future.cancelled():
+                future.set_exception(exc)
+
+            # Let base exceptions fall through
+            if not isinstance(exc, Exception):
+                raise
+        else:
+            if not future.cancelled():
+                future.set_result(retval)
+        finally:
+            scope = None  # type: ignore[assignment]
+
+    def _spawn_task_from_thread(
+        self,
+        func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval] | T_Retval],
+        args: tuple[Unpack[PosArgsT]],
+        kwargs: dict[str, Any],
+        name: object,
+        future: Future[T_Retval],
+    ) -> None:
+        """
+        Spawn a new task using the given callable.
+
+        :param func: a callable
+        :param args: positional arguments to be passed to the callable
+        :param kwargs: keyword arguments to be passed to the callable
+        :param name: name of the task (will be coerced to a string if not ``None``)
+        :param future: a future that will resolve to the return value of the callable,
+            or the exception raised during its execution
+
+        """
+        run_sync(
+            partial(self._task_group.start_soon, name=name),
+            self._call_func,
+            func,
+            args,
+            kwargs,
+            future,
+            token=self._token,
+        )
+
+    @overload
+    def call(
+        self,
+        func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval]],
+        *args: Unpack[PosArgsT],
+    ) -> T_Retval: ...
+
+    @overload
+    def call(
+        self, func: Callable[[Unpack[PosArgsT]], T_Retval], *args: Unpack[PosArgsT]
+    ) -> T_Retval: ...
+
+    def call(
+        self,
+        func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval] | T_Retval],
+        *args: Unpack[PosArgsT],
+    ) -> T_Retval:
+        """
+        Call the given function in the event loop thread.
+
+        If the callable returns a coroutine object, it is awaited on.
+
+        :param func: any callable
+        :raises RuntimeError: if the portal is not running or if this method is called
+            from within the event loop thread
+
+        """
+        return cast(T_Retval, self.start_task_soon(func, *args).result())
+
+    @overload
+    def start_task_soon(
+        self,
+        func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval]],
+        *args: Unpack[PosArgsT],
+        name: object = None,
+    ) -> Future[T_Retval]: ...
+
+    @overload
+    def start_task_soon(
+        self,
+        func: Callable[[Unpack[PosArgsT]], T_Retval],
+        *args: Unpack[PosArgsT],
+        name: object = None,
+    ) -> Future[T_Retval]: ...
+
+    def start_task_soon(
+        self,
+        func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval] | T_Retval],
+        *args: Unpack[PosArgsT],
+        name: object = None,
+    ) -> Future[T_Retval]:
+        """
+        Start a task in the portal's task group.
+
+        The task will be run inside a cancel scope which can be cancelled by cancelling
+        the returned future.
+
+        :param func: the target function
+        :param args: positional arguments passed to ``func``
+        :param name: name of the task (will be coerced to a string if not ``None``)
+        :return: a future that resolves with the return value of the callable if the
+            task completes successfully, or with the exception raised in the task
+        :raises RuntimeError: if the portal is not running or if this method is called
+            from within the event loop thread
+        :rtype: concurrent.futures.Future[T_Retval]
+
+        .. versionadded:: 3.0
+
+        """
+        self._check_running()
+        f: Future[T_Retval] = Future()
+        self._spawn_task_from_thread(func, args, {}, name, f)
+        return f
+
+    def start_task(
+        self,
+        func: Callable[..., Awaitable[T_Retval]],
+        *args: object,
+        name: object = None,
+    ) -> tuple[Future[T_Retval], Any]:
+        """
+        Start a task in the portal's task group and wait until it signals for readiness.
+
+        This method works the same way as :meth:`.abc.TaskGroup.start`.
+
+        :param func: the target function
+        :param args: positional arguments passed to ``func``
+        :param name: name of the task (will be coerced to a string if not ``None``)
+        :return: a tuple of (future, task_status_value) where the ``task_status_value``
+            is the value passed to ``task_status.started()`` from within the target
+            function
+        :rtype: tuple[concurrent.futures.Future[T_Retval], Any]
+
+        .. versionadded:: 3.0
+
+        """
+
+        def task_done(future: Future[T_Retval]) -> None:
+            if not task_status_future.done():
+                if future.cancelled():
+                    task_status_future.cancel()
+                elif future.exception():
+                    task_status_future.set_exception(future.exception())
+                else:
+                    exc = RuntimeError(
+                        "Task exited without calling task_status.started()"
+                    )
+                    task_status_future.set_exception(exc)
+
+        self._check_running()
+        task_status_future: Future = Future()
+        task_status = _BlockingPortalTaskStatus(task_status_future)
+        f: Future = Future()
+        f.add_done_callback(task_done)
+        self._spawn_task_from_thread(func, args, {"task_status": task_status}, name, f)
+        return f, task_status_future.result()
+
+    def wrap_async_context_manager(
+        self, cm: AbstractAsyncContextManager[T_co]
+    ) -> AbstractContextManager[T_co]:
+        """
+        Wrap an async context manager as a synchronous context manager via this portal.
+
+        Spawns a task that will call both ``__aenter__()`` and ``__aexit__()``, stopping
+        in the middle until the synchronous context manager exits.
+
+        :param cm: an asynchronous context manager
+        :return: a synchronous context manager
+
+        .. versionadded:: 2.1
+
+        """
+        return _BlockingAsyncContextManager(cm, self)
+
+
+@dataclass
+class BlockingPortalProvider:
+    """
+    A manager for a blocking portal. Used as a context manager. The first thread to
+    enter this context manager causes a blocking portal to be started with the specific
+    parameters, and the last thread to exit causes the portal to be shut down. Thus,
+    there will be exactly one blocking portal running in this context as long as at
+    least one thread has entered this context manager.
+
+    The parameters are the same as for :func:`~anyio.run`.
+
+    :param backend: name of the backend
+    :param backend_options: backend options
+
+    .. versionadded:: 4.4
+    """
+
+    backend: str = "asyncio"
+    backend_options: dict[str, Any] | None = None
+    _lock: Lock = field(init=False, default_factory=Lock)
+    _leases: int = field(init=False, default=0)
+    _portal: BlockingPortal = field(init=False)
+    _portal_cm: AbstractContextManager[BlockingPortal] | None = field(
+        init=False, default=None
+    )
+
+    def __enter__(self) -> BlockingPortal:
+        with self._lock:
+            if self._portal_cm is None:
+                self._portal_cm = start_blocking_portal(
+                    self.backend, self.backend_options
+                )
+                self._portal = self._portal_cm.__enter__()
+
+            self._leases += 1
+            return self._portal
+
+    def __exit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
+    ) -> None:
+        portal_cm: AbstractContextManager[BlockingPortal] | None = None
+        with self._lock:
+            assert self._portal_cm
+            assert self._leases > 0
+            self._leases -= 1
+            if not self._leases:
+                portal_cm = self._portal_cm
+                self._portal_cm = None
+                del self._portal
+
+        if portal_cm:
+            portal_cm.__exit__(None, None, None)
+
+
+@contextmanager
+def start_blocking_portal(
+    backend: str = "asyncio",
+    backend_options: dict[str, Any] | None = None,
+    *,
+    name: str | None = None,
+) -> Generator[BlockingPortal, Any, None]:
+    """
+    Start a new event loop in a new thread and run a blocking portal in its main task.
+
+    The parameters are the same as for :func:`~anyio.run`.
+
+    :param backend: name of the backend
+    :param backend_options: backend options
+    :param name: name of the thread
+    :return: a context manager that yields a blocking portal
+
+    .. versionchanged:: 3.0
+        Usage as a context manager is now required.
+
+    """
+
+    async def run_portal() -> None:
+        async with BlockingPortal() as portal_:
+            if name is None:
+                current_thread().name = f"{backend}-portal-{id(portal_):x}"
+
+            future.set_result(portal_)
+            await portal_.sleep_until_stopped()
+
+    def run_blocking_portal() -> None:
+        if future.set_running_or_notify_cancel():
+            try:
+                run_eventloop(
+                    run_portal, backend=backend, backend_options=backend_options
+                )
+            except BaseException as exc:
+                if not future.done():
+                    future.set_exception(exc)
+
+    future: Future[BlockingPortal] = Future()
+    thread = Thread(target=run_blocking_portal, daemon=True, name=name)
+    thread.start()
+    try:
+        cancel_remaining_tasks = False
+        portal = future.result()
+        try:
+            yield portal
+        except BaseException:
+            cancel_remaining_tasks = True
+            raise
+        finally:
+            try:
+                portal.call(portal.stop, cancel_remaining_tasks)
+            except RuntimeError:
+                pass
+    finally:
+        thread.join()
+
+
+def check_cancelled() -> None:
+    """
+    Check if the cancel scope of the host task's running the current worker thread has
+    been cancelled.
+
+    If the host task's current cancel scope has indeed been cancelled, the
+    backend-specific cancellation exception will be raised.
+
+    :raises RuntimeError: if the current thread was not spawned by
+        :func:`.to_thread.run_sync`
+
+    """
+    try:
+        token: EventLoopToken = threadlocals.current_token
+    except AttributeError:
+        raise NoEventLoopError(
+            "This function can only be called inside an AnyIO worker thread"
+        ) from None
+
+    token.backend_class.check_cancelled()

venv/Lib/site-packages/anyio/functools.py

@@ -0,0 +1,400 @@
+from __future__ import annotations
+
+__all__ = (
+    "AsyncCacheInfo",
+    "AsyncCacheParameters",
+    "AsyncLRUCacheWrapper",
+    "cache",
+    "lru_cache",
+    "reduce",
+)
+
+import functools
+from collections import OrderedDict
+from collections.abc import (
+    AsyncIterable,
+    Awaitable,
+    Callable,
+    Coroutine,
+    Hashable,
+    Iterable,
+)
+from functools import update_wrapper
+from inspect import iscoroutinefunction
+from typing import (
+    Any,
+    Generic,
+    NamedTuple,
+    ParamSpec,
+    TypedDict,
+    TypeVar,
+    cast,
+    final,
+    overload,
+)
+from weakref import WeakKeyDictionary
+
+from ._core._eventloop import current_time
+from ._core._synchronization import Lock
+from .lowlevel import RunVar, checkpoint
+
+T = TypeVar("T")
+S = TypeVar("S")
+P = ParamSpec("P")
+lru_cache_items: RunVar[
+    WeakKeyDictionary[
+        AsyncLRUCacheWrapper[Any, Any],
+        OrderedDict[
+            Hashable,
+            tuple[_InitialMissingType, Lock, float | None]
+            | tuple[Any, None, float | None],
+        ],
+    ]
+] = RunVar("lru_cache_items")
+
+
+class _InitialMissingType:
+    pass
+
+
+initial_missing: _InitialMissingType = _InitialMissingType()
+
+
+class AsyncCacheInfo(NamedTuple):
+    hits: int
+    misses: int
+    maxsize: int | None
+    currsize: int
+    ttl: int | None
+
+
+class AsyncCacheParameters(TypedDict):
+    maxsize: int | None
+    typed: bool
+    always_checkpoint: bool
+    ttl: int | None
+
+
+class _LRUMethodWrapper(Generic[T]):
+    def __init__(self, wrapper: AsyncLRUCacheWrapper[..., T], instance: object):
+        self.__wrapper = wrapper
+        self.__instance = instance
+
+    def cache_info(self) -> AsyncCacheInfo:
+        return self.__wrapper.cache_info()
+
+    def cache_parameters(self) -> AsyncCacheParameters:
+        return self.__wrapper.cache_parameters()
+
+    def cache_clear(self) -> None:
+        self.__wrapper.cache_clear()
+
+    async def __call__(self, *args: Any, **kwargs: Any) -> T:
+        if self.__instance is None:
+            return await self.__wrapper(*args, **kwargs)
+
+        return await self.__wrapper(self.__instance, *args, **kwargs)
+
+
+@final
+class AsyncLRUCacheWrapper(Generic[P, T]):
+    def __init__(
+        self,
+        func: Callable[P, Awaitable[T]],
+        maxsize: int | None,
+        typed: bool,
+        always_checkpoint: bool,
+        ttl: int | None,
+    ):
+        self.__wrapped__ = func
+        self._hits: int = 0
+        self._misses: int = 0
+        self._maxsize = max(maxsize, 0) if maxsize is not None else None
+        self._currsize: int = 0
+        self._typed = typed
+        self._always_checkpoint = always_checkpoint
+        self._ttl = ttl
+        update_wrapper(self, func)
+
+    def cache_info(self) -> AsyncCacheInfo:
+        return AsyncCacheInfo(
+            self._hits, self._misses, self._maxsize, self._currsize, self._ttl
+        )
+
+    def cache_parameters(self) -> AsyncCacheParameters:
+        return {
+            "maxsize": self._maxsize,
+            "typed": self._typed,
+            "always_checkpoint": self._always_checkpoint,
+            "ttl": self._ttl,
+        }
+
+    def cache_clear(self) -> None:
+        if cache := lru_cache_items.get(None):
+            cache.pop(self, None)
+            self._hits = self._misses = self._currsize = 0
+
+    async def __call__(self, *args: P.args, **kwargs: P.kwargs) -> T:
+        # Easy case first: if maxsize == 0, no caching is done
+        if self._maxsize == 0:
+            value = await self.__wrapped__(*args, **kwargs)
+            self._misses += 1
+            return value
+
+        # The key is constructed as a flat tuple to avoid memory overhead
+        key: tuple[Any, ...] = args
+        if kwargs:
+            # initial_missing is used as a separator
+            key += (initial_missing,) + sum(kwargs.items(), ())
+
+        if self._typed:
+            key += tuple(type(arg) for arg in args)
+            if kwargs:
+                key += (initial_missing,) + tuple(type(val) for val in kwargs.values())
+
+        try:
+            cache = lru_cache_items.get()
+        except LookupError:
+            cache = WeakKeyDictionary()
+            lru_cache_items.set(cache)
+
+        try:
+            cache_entry = cache[self]
+        except KeyError:
+            cache_entry = cache[self] = OrderedDict()
+
+        cached_value: T | _InitialMissingType
+        try:
+            cached_value, lock, expires_at = cache_entry[key]
+        except KeyError:
+            # We're the first task to call this function
+            cached_value, lock, expires_at = (
+                initial_missing,
+                Lock(fast_acquire=not self._always_checkpoint),
+                None,
+            )
+            cache_entry[key] = cached_value, lock, expires_at
+
+        if lock is None:
+            if expires_at is not None and current_time() >= expires_at:
+                self._currsize -= 1
+                cached_value, lock, expires_at = (
+                    initial_missing,
+                    Lock(fast_acquire=not self._always_checkpoint),
+                    None,
+                )
+                cache_entry[key] = cached_value, lock, expires_at
+            else:
+                # The value was already cached
+                self._hits += 1
+                cache_entry.move_to_end(key)
+                if self._always_checkpoint:
+                    await checkpoint()
+
+                return cast(T, cached_value)
+
+        async with lock:
+            # Check if another task filled the cache while we acquired the lock
+            if (cached_value := cache_entry[key][0]) is initial_missing:
+                self._misses += 1
+                if self._maxsize is not None and self._currsize >= self._maxsize:
+                    cache_entry.popitem(last=False)
+                else:
+                    self._currsize += 1
+
+                value = await self.__wrapped__(*args, **kwargs)
+                expires_at = (
+                    current_time() + self._ttl if self._ttl is not None else None
+                )
+                cache_entry[key] = value, None, expires_at
+            else:
+                # Another task filled the cache while we were waiting for the lock
+                self._hits += 1
+                cache_entry.move_to_end(key)
+                value = cast(T, cached_value)
+
+        return value
+
+    def __get__(
+        self, instance: object, owner: type | None = None
+    ) -> _LRUMethodWrapper[T]:
+        wrapper = _LRUMethodWrapper(self, instance)
+        update_wrapper(wrapper, self.__wrapped__)
+        return wrapper
+
+
+class _LRUCacheWrapper:
+    def __init__(
+        self, maxsize: int | None, typed: bool, always_checkpoint: bool, ttl: int | None
+    ):
+        self._maxsize = maxsize
+        self._typed = typed
+        self._always_checkpoint = always_checkpoint
+        self._ttl = ttl
+
+    @overload
+    def __call__(  # type: ignore[overload-overlap]
+        self, func: Callable[P, Coroutine[Any, Any, T]], /
+    ) -> AsyncLRUCacheWrapper[P, T]: ...
+
+    @overload
+    def __call__(
+        self, func: Callable[..., T], /
+    ) -> functools._lru_cache_wrapper[T]: ...
+
+    def __call__(
+        self, f: Callable[P, Coroutine[Any, Any, T]] | Callable[..., T], /
+    ) -> AsyncLRUCacheWrapper[P, T] | functools._lru_cache_wrapper[T]:
+        if iscoroutinefunction(f):
+            return AsyncLRUCacheWrapper(
+                f, self._maxsize, self._typed, self._always_checkpoint, self._ttl
+            )
+
+        return functools.lru_cache(maxsize=self._maxsize, typed=self._typed)(f)  # type: ignore[arg-type]
+
+
+@overload
+def cache(  # type: ignore[overload-overlap]
+    func: Callable[P, Coroutine[Any, Any, T]], /
+) -> AsyncLRUCacheWrapper[P, T]: ...
+
+
+@overload
+def cache(func: Callable[..., T], /) -> functools._lru_cache_wrapper[T]: ...
+
+
+def cache(func: Callable[..., Any] | Callable[P, Coroutine[Any, Any, Any]], /) -> Any:
+    """
+    A convenient shortcut for :func:`lru_cache` with ``maxsize=None``.
+
+    This is the asynchronous equivalent to :func:`functools.cache`.
+
+    """
+    return lru_cache(maxsize=None)(func)
+
+
+@overload
+def lru_cache(
+    *,
+    maxsize: int | None = ...,
+    typed: bool = ...,
+    always_checkpoint: bool = ...,
+    ttl: int | None = ...,
+) -> _LRUCacheWrapper: ...
+
+
+@overload
+def lru_cache(  # type: ignore[overload-overlap]
+    func: Callable[P, Coroutine[Any, Any, T]], /
+) -> AsyncLRUCacheWrapper[P, T]: ...
+
+
+@overload
+def lru_cache(func: Callable[..., T], /) -> functools._lru_cache_wrapper[T]: ...
+
+
+def lru_cache(
+    func: Callable[..., Coroutine[Any, Any, Any]] | Callable[..., Any] | None = None,
+    /,
+    *,
+    maxsize: int | None = 128,
+    typed: bool = False,
+    always_checkpoint: bool = False,
+    ttl: int | None = None,
+) -> Any:
+    """
+    An asynchronous version of :func:`functools.lru_cache`.
+
+    If a synchronous function is passed, the standard library
+    :func:`functools.lru_cache` is applied instead.
+
+    :param always_checkpoint: if ``True``, every call to the cached function will be
+        guaranteed to yield control to the event loop at least once
+    :param ttl: time in seconds after which to invalidate cache entries
+
+    .. note:: Caches and locks are managed on a per-event loop basis.
+
+    """
+    if func is None:
+        return _LRUCacheWrapper(maxsize, typed, always_checkpoint, ttl)
+
+    if not callable(func):
+        raise TypeError("the first argument must be callable")
+
+    return _LRUCacheWrapper(maxsize, typed, always_checkpoint, ttl)(func)
+
+
+@overload
+async def reduce(
+    function: Callable[[T, S], Awaitable[T]],
+    iterable: Iterable[S] | AsyncIterable[S],
+    /,
+    initial: T,
+) -> T: ...
+
+
+@overload
+async def reduce(
+    function: Callable[[T, T], Awaitable[T]],
+    iterable: Iterable[T] | AsyncIterable[T],
+    /,
+) -> T: ...
+
+
+async def reduce(  # type: ignore[misc]
+    function: Callable[[T, T], Awaitable[T]] | Callable[[T, S], Awaitable[T]],
+    iterable: Iterable[T] | Iterable[S] | AsyncIterable[T] | AsyncIterable[S],
+    /,
+    initial: T | _InitialMissingType = initial_missing,
+) -> T:
+    """
+    Asynchronous version of :func:`functools.reduce`.
+
+    :param function: a coroutine function that takes two arguments: the accumulated
+        value and the next element from the iterable
+    :param iterable: an iterable or async iterable
+    :param initial: the initial value (if missing, the first element of the iterable is
+        used as the initial value)
+
+    """
+    element: Any
+    function_called = False
+    if isinstance(iterable, AsyncIterable):
+        async_it = iterable.__aiter__()
+        if initial is initial_missing:
+            try:
+                value = cast(T, await async_it.__anext__())
+            except StopAsyncIteration:
+                raise TypeError(
+                    "reduce() of empty sequence with no initial value"
+                ) from None
+        else:
+            value = cast(T, initial)
+
+        async for element in async_it:
+            value = await function(value, element)
+            function_called = True
+    elif isinstance(iterable, Iterable):
+        it = iter(iterable)
+        if initial is initial_missing:
+            try:
+                value = cast(T, next(it))
+            except StopIteration:
+                raise TypeError(
+                    "reduce() of empty sequence with no initial value"
+                ) from None
+        else:
+            value = cast(T, initial)
+
+        for element in it:
+            value = await function(value, element)
+            function_called = True
+    else:
+        raise TypeError("reduce() argument 2 must be an iterable or async iterable")
+
+    # Make sure there is at least one checkpoint, even if an empty iterable and an
+    # initial value were given
+    if not function_called:
+        await checkpoint()
+
+    return value

venv/Lib/site-packages/anyio/itertools.py

@@ -0,0 +1,626 @@
+from __future__ import annotations
+
+__all__ = (
+    "accumulate",
+    "batched",
+    "Chain",
+    "combinations",
+    "combinations_with_replacement",
+    "compress",
+    "count",
+    "cycle",
+    "dropwhile",
+    "filterfalse",
+    "groupby",
+    "islice",
+    "pairwise",
+    "permutations",
+    "product",
+    "repeat",
+    "starmap",
+    "tee",
+    "takewhile",
+    "zip_longest",
+)
+
+import itertools
+import operator
+import sys
+from collections.abc import (
+    AsyncGenerator,
+    AsyncIterable,
+    AsyncIterator,
+    Awaitable,
+    Callable,
+    Iterable,
+    Iterator,
+)
+from dataclasses import dataclass, field
+from typing import Any, Generic, TypeVar, cast, overload
+
+from ._core._synchronization import Lock
+from ._core._tasks import CancelScope
+from .lowlevel import cancel_shielded_checkpoint, checkpoint, checkpoint_if_cancelled
+
+T = TypeVar("T")
+R = TypeVar("R")
+_tee_end = object()
+
+
+@dataclass(eq=False)
+class _IterableAsyncIterator(AsyncIterator[T]):
+    iterator: Iterator[T]
+
+    async def __anext__(self) -> T:
+        await checkpoint_if_cancelled()
+        try:
+            result = next(self.iterator)
+        except StopIteration:
+            await cancel_shielded_checkpoint()
+            raise StopAsyncIteration from None
+
+        await cancel_shielded_checkpoint()
+        return result
+
+
+def _iterate(iterable: Iterable[T] | AsyncIterable[T]) -> AsyncIterator[T]:
+    if isinstance(iterable, AsyncIterator):
+        return iterable
+
+    if isinstance(iterable, AsyncIterable):
+        return iterable.__aiter__()
+
+    return _IterableAsyncIterator(iter(iterable))
+
+
+@dataclass(eq=False)
+class _TeeLink(Generic[T]):
+    value: object | None = None
+    next: _TeeLink[T] | None = None
+    filled: bool = False
+
+
+@dataclass(eq=False)
+class _TeeState(Generic[T]):
+    iterator: AsyncIterator[T]
+    lock: Lock = field(default_factory=Lock)
+
+    async def fill(self, link: _TeeLink[T]) -> bool:
+        if link.filled:
+            return False
+
+        async with self.lock:
+            if link.filled:
+                return True
+
+            link.value = await anext(self.iterator, _tee_end)
+            if link.value is not _tee_end:
+                link.next = _TeeLink()
+
+            link.filled = True
+            return True
+
+
+class _TeeAsyncIterator(AsyncIterator[T]):
+    _state: _TeeState[T]
+    _link: _TeeLink[T]
+    _element_yielded: bool
+
+    def __init__(
+        self, iterable: Iterable[T] | AsyncIterable[T] | _TeeAsyncIterator[T]
+    ) -> None:
+        if isinstance(iterable, _TeeAsyncIterator):
+            self._state = iterable._state
+            self._link = iterable._link
+        else:
+            self._state = _TeeState(_iterate(iterable))
+            self._link = _TeeLink()
+
+        self._element_yielded = False
+
+    async def __anext__(self) -> T:
+        had_yieldpoint = await self._state.fill(self._link)
+        if self._link.value is _tee_end:
+            if not self._element_yielded:
+                await checkpoint()
+
+            raise StopAsyncIteration
+
+        if not had_yieldpoint:
+            await checkpoint_if_cancelled()
+
+        self._element_yielded = True
+        value = cast(T, self._link.value)
+        next_link = self._link.next
+        assert next_link is not None
+        self._link = next_link
+        if not had_yieldpoint:
+            await cancel_shielded_checkpoint()
+
+        return value
+
+
+async def _operator_add(x: T, y: T) -> T:
+    return operator.add(x, y)
+
+
+async def accumulate(
+    iterable: Iterable[T] | AsyncIterable[T],
+    function: Callable[[T, T], Awaitable[T]] = _operator_add,
+    *,
+    initial: T | None = None,
+) -> AsyncGenerator[T, None]:
+    iterator = _iterate(iterable)
+    if initial is None:
+        try:
+            total = await anext(iterator)
+        except StopAsyncIteration:
+            await checkpoint()
+            return
+    else:
+        await checkpoint_if_cancelled()
+        total = initial
+        await cancel_shielded_checkpoint()
+
+    yield total
+
+    async for element in iterator:
+        total = await function(total, element)
+        yield total
+
+
+async def batched(
+    iterable: Iterable[T] | AsyncIterable[T], n: int, *, strict: bool = False
+) -> AsyncGenerator[tuple[T, ...], None]:
+    if n < 1:
+        raise ValueError("n must be at least one")
+
+    iterator = _iterate(iterable)
+
+    while True:
+        batch: list[T] = []
+        for _ in range(n):
+            try:
+                batch.append(await anext(iterator))
+            except StopAsyncIteration:
+                if not batch:
+                    await checkpoint()
+                    return
+                if strict:
+                    raise ValueError("batched(): incomplete batch") from None
+
+                yield tuple(batch)
+                return
+
+        yield tuple(batch)
+
+
+class Chain:
+    def __call__(
+        self, *iterables: Iterable[T] | AsyncIterable[T]
+    ) -> AsyncGenerator[T, None]:
+        return self.from_iterable(iterables)
+
+    async def from_iterable(
+        self,
+        iterables: (
+            Iterable[Iterable[T] | AsyncIterable[T]]
+            | AsyncIterable[Iterable[T] | AsyncIterable[T]]
+        ),
+    ) -> AsyncGenerator[T, None]:
+        element_yielded = False
+        outer_iter = _iterate(iterables)
+
+        try:
+            async for iterable in outer_iter:
+                async for element in _iterate(iterable):
+                    element_yielded = True
+                    yield element
+        finally:
+            aclose = getattr(outer_iter, "aclose", None)
+            if aclose is not None:
+                with CancelScope(shield=True):
+                    await aclose()
+
+        if not element_yielded:
+            await checkpoint()
+
+
+chain: Chain = Chain()
+
+
+async def combinations(
+    iterable: Iterable[T] | AsyncIterable[T], r: int
+) -> AsyncGenerator[tuple[T, ...], None]:
+    pool: list[T] = [element async for element in _iterate(iterable)]
+    async for combination in _iterate(itertools.combinations(pool, r)):
+        yield combination
+
+
+async def combinations_with_replacement(
+    iterable: Iterable[T] | AsyncIterable[T], r: int
+) -> AsyncGenerator[tuple[T, ...], None]:
+    pool: list[T] = [element async for element in _iterate(iterable)]
+    async for combination in _iterate(itertools.combinations_with_replacement(pool, r)):
+        yield combination
+
+
+async def compress(
+    data: Iterable[T] | AsyncIterable[T],
+    selectors: Iterable[object] | AsyncIterable[object],
+) -> AsyncGenerator[T, None]:
+    data_iterator = _iterate(data)
+    selector_iterator = _iterate(selectors)
+    element_yielded = False
+
+    while True:
+        try:
+            datum = await anext(data_iterator)
+            selector = await anext(selector_iterator)
+        except StopAsyncIteration:
+            if not element_yielded:
+                await checkpoint()
+
+            return
+
+        if selector:
+            element_yielded = True
+            yield datum
+
+
+async def count(start: int = 0, step: int = 1) -> AsyncGenerator[int, None]:
+    n = start
+    while True:
+        await checkpoint_if_cancelled()
+        value = n
+        n += step
+        await cancel_shielded_checkpoint()
+        yield value
+
+
+async def cycle(
+    iterable: Iterable[T] | AsyncIterable[T],
+) -> AsyncGenerator[T, None]:
+    saved: list[T] = []
+    async for element in _iterate(iterable):
+        saved.append(element)
+        yield element
+
+    if not saved:
+        await checkpoint()
+        return
+
+    while True:
+        for element in saved:
+            await checkpoint()
+            yield element
+
+
+async def dropwhile(
+    predicate: Callable[[T], Awaitable[object]],
+    iterable: Iterable[T] | AsyncIterable[T],
+) -> AsyncGenerator[T, None]:
+    element_yielded = False
+    dropping = True
+
+    async for element in _iterate(iterable):
+        if dropping and await predicate(element):
+            continue
+
+        dropping = False
+        element_yielded = True
+        yield element
+
+    if not element_yielded:
+        await checkpoint()
+
+
+async def filterfalse(
+    predicate: Callable[[T], Awaitable[object]],
+    iterable: Iterable[T] | AsyncIterable[T],
+) -> AsyncGenerator[T, None]:
+    element_yielded = False
+
+    async for element in _iterate(iterable):
+        if not await predicate(element):
+            element_yielded = True
+            yield element
+
+    if not element_yielded:
+        await checkpoint()
+
+
+@overload
+def groupby(
+    iterable: Iterable[T] | AsyncIterable[T],
+) -> AsyncGenerator[tuple[T, list[T]], None]: ...
+
+
+@overload
+def groupby(
+    iterable: Iterable[T] | AsyncIterable[T],
+    key: Callable[[T], Awaitable[R]],
+) -> AsyncGenerator[tuple[R, list[T]], None]: ...
+
+
+async def groupby(
+    iterable: Iterable[T] | AsyncIterable[T],
+    key: Callable[[T], Awaitable[object]] | None = None,
+) -> AsyncGenerator[tuple[object, list[T]], None]:
+    iterator = _iterate(iterable)
+    try:
+        element = await anext(iterator)
+    except StopAsyncIteration:
+        await checkpoint()
+        return
+
+    group_key = element if key is None else await key(element)
+    values = [element]
+
+    async for element in iterator:
+        next_key = element if key is None else await key(element)
+        if next_key != group_key:
+            completed_group = group_key, values
+            group_key = next_key
+            values = [element]
+            yield completed_group
+        else:
+            values.append(element)
+
+    yield group_key, values
+
+
+@overload
+def islice(
+    iterable: Iterable[T] | AsyncIterable[T],
+    stop: int | None,
+    /,
+) -> AsyncGenerator[T, None]: ...
+
+
+@overload
+def islice(
+    iterable: Iterable[T] | AsyncIterable[T],
+    start: int | None,
+    stop: int | None,
+    step: int | None = 1,
+    /,
+) -> AsyncGenerator[T, None]: ...
+
+
+async def islice(
+    iterable: Iterable[T] | AsyncIterable[T],
+    *args: int | None,
+) -> AsyncGenerator[T, None]:
+    if not args:
+        raise TypeError("islice expected at least 2 arguments, got 1")
+    if len(args) > 3:
+        raise TypeError(f"islice expected at most 4 arguments, got {len(args) + 1}")
+
+    slice_args = slice(*args)
+
+    start_message = (
+        "Indices for islice() must be None or an integer: 0 <= x <= sys.maxsize."
+    )
+    stop_message = (
+        "Stop argument for islice() must be None or an integer: 0 <= x <= sys.maxsize."
+    )
+    step_message = "Step for islice() must be a positive integer or None."
+
+    def normalize_index(value: object, message: str) -> int:
+        try:
+            index = operator.index(cast(Any, value))
+        except TypeError:
+            raise ValueError(message) from None
+
+        if index < 0 or index > sys.maxsize:
+            raise ValueError(message)
+
+        return index
+
+    start = (
+        0
+        if slice_args.start is None
+        else normalize_index(slice_args.start, start_message)
+    )
+    stop = (
+        None
+        if slice_args.stop is None
+        else normalize_index(slice_args.stop, stop_message)
+    )
+    step = (
+        1 if slice_args.step is None else normalize_index(slice_args.step, step_message)
+    )
+
+    if step <= 0:
+        raise ValueError(step_message)
+
+    if stop == 0 or start == stop:
+        await checkpoint()
+        return
+
+    iterator = _iterate(iterable)
+    index = 0
+    element_yielded = False
+
+    while stop is None or index < stop:
+        try:
+            element = await anext(iterator)
+        except StopAsyncIteration:
+            if not element_yielded:
+                await checkpoint()
+
+            return
+
+        if index >= start and (index - start) % step == 0:
+            index += 1
+            element_yielded = True
+            yield element
+        else:
+            index += 1
+
+    if not element_yielded:
+        await checkpoint()
+
+
+async def pairwise(
+    iterable: Iterable[T] | AsyncIterable[T],
+) -> AsyncGenerator[tuple[T, T], None]:
+    iterator = _iterate(iterable)
+    try:
+        previous = await anext(iterator)
+    except StopAsyncIteration:
+        await checkpoint()
+        return
+
+    element_yielded = False
+    async for element in iterator:
+        element_yielded = True
+        pair = (previous, element)
+        previous = element
+        yield pair
+
+    if not element_yielded:
+        await checkpoint()
+
+
+async def permutations(
+    iterable: Iterable[T] | AsyncIterable[T], r: int | None = None
+) -> AsyncGenerator[tuple[T, ...], None]:
+    pool: list[T] = [element async for element in _iterate(iterable)]
+    n = len(pool)
+    if r is None:
+        r = n
+    elif not isinstance(r, int):
+        raise TypeError("Expected int as r")
+    elif r < 0:
+        raise ValueError("r must be non-negative")
+
+    async for permutation in _iterate(itertools.permutations(pool, r)):
+        yield permutation
+
+
+async def product(
+    *iterables: Iterable[T] | AsyncIterable[T], repeat: int = 1
+) -> AsyncGenerator[tuple[T, ...], None]:
+    repeat = operator.index(repeat)
+    if repeat < 0:
+        raise ValueError("repeat argument cannot be negative")
+
+    pools: list[tuple[T, ...]] = []
+    for iterable in iterables:
+        pool: list[T] = [element async for element in _iterate(iterable)]
+        pools.append(tuple(pool))
+
+    async for value in _iterate(itertools.product(*pools, repeat=repeat)):
+        yield value
+
+
+async def repeat(element: T, times: int | None = None) -> AsyncGenerator[T, None]:
+    if times is None:
+        while True:
+            await checkpoint()
+            yield element
+
+    remaining = operator.index(cast(Any, times))
+    if remaining <= 0:
+        await checkpoint()
+        return
+
+    while remaining > 0:
+        await checkpoint_if_cancelled()
+        remaining -= 1
+        await cancel_shielded_checkpoint()
+        yield element
+
+
+async def starmap(
+    function: Callable[..., Awaitable[R]],
+    iterable: (
+        Iterable[Iterable[object] | AsyncIterable[object]]
+        | AsyncIterable[Iterable[object] | AsyncIterable[object]]
+    ),
+) -> AsyncGenerator[R, None]:
+    result_yielded = False
+
+    async for args_iterable in _iterate(iterable):
+        args = [element async for element in _iterate(args_iterable)]
+        result_yielded = True
+        yield await function(*args)
+
+    if not result_yielded:
+        await checkpoint()
+
+
+def tee(
+    iterable: Iterable[T] | AsyncIterable[T], n: int = 2
+) -> tuple[AsyncIterator[T], ...]:
+    n = operator.index(cast(Any, n))
+    if n < 0:
+        raise ValueError("n must be >= 0")
+    if n == 0:
+        return ()
+
+    iterator = _TeeAsyncIterator(iterable)
+    iterators: list[AsyncIterator[T]] = [iterator]
+    iterators.extend(_TeeAsyncIterator(iterator) for _ in range(n - 1))
+    return tuple(iterators)
+
+
+async def takewhile(
+    predicate: Callable[[T], Awaitable[object]],
+    iterable: Iterable[T] | AsyncIterable[T],
+) -> AsyncGenerator[T, None]:
+    element_yielded = False
+
+    async for element in _iterate(iterable):
+        if not await predicate(element):
+            if not element_yielded:
+                await checkpoint()
+
+            return
+
+        element_yielded = True
+        yield element
+
+    if not element_yielded:
+        await checkpoint()
+
+
+async def zip_longest(
+    *iterables: Iterable[object] | AsyncIterable[object],
+    fillvalue: object = None,
+) -> AsyncGenerator[tuple[object, ...], None]:
+    iterators = [_iterate(iterable) for iterable in iterables]
+    num_active = len(iterators)
+    if not num_active:
+        await checkpoint()
+        return
+
+    active = [True] * num_active
+    tuple_yielded = False
+
+    while True:
+        values: list[object] = []
+        for index, iterator in enumerate(iterators):
+            if not active[index]:
+                values.append(fillvalue)
+                continue
+
+            try:
+                value = await anext(iterator)
+            except StopAsyncIteration:
+                active[index] = False
+                num_active -= 1
+                if not num_active:
+                    if not tuple_yielded:
+                        await checkpoint()
+
+                    return
+
+                value = fillvalue
+
+            values.append(value)
+
+        tuple_yielded = True
+        yield tuple(values)

venv/Lib/site-packages/anyio/lowlevel.py

@@ -0,0 +1,226 @@
+from __future__ import annotations
+
+__all__ = (
+    "EventLoopToken",
+    "RunvarToken",
+    "RunVar",
+    "checkpoint",
+    "checkpoint_if_cancelled",
+    "cancel_shielded_checkpoint",
+    "current_token",
+)
+
+import enum
+from dataclasses import dataclass
+from types import TracebackType
+from typing import Any, Generic, Literal, TypeVar, final, overload
+from weakref import WeakKeyDictionary
+
+from ._core._eventloop import get_async_backend
+from .abc import AsyncBackend
+
+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()
+
+
+@final
+@dataclass(frozen=True, repr=False)
+class EventLoopToken:
+    """
+    An opaque object that holds a reference to an event loop.
+
+    .. versionadded:: 4.11.0
+    """
+
+    backend_class: type[AsyncBackend]
+    native_token: object
+
+
+def current_token() -> EventLoopToken:
+    """
+    Return a token object that can be used to call code in the current event loop from
+    another thread.
+
+    :raises NoEventLoopError: if no supported asynchronous event loop is running in the
+        current thread
+
+    .. versionadded:: 4.11.0
+
+    """
+    backend_class = get_async_backend()
+    raw_token = backend_class.current_token()
+    return EventLoopToken(backend_class, raw_token)
+
+
+_run_vars: WeakKeyDictionary[object, dict[RunVar[Any], Any]] = WeakKeyDictionary()
+
+
+class _NoValueSet(enum.Enum):
+    NO_VALUE_SET = enum.auto()
+
+
+class RunvarToken(Generic[T]):
+    """
+    A token that can be used to restore a :class:`RunVar` to its previous value.
+
+    Returned by :meth:`RunVar.set`. Can be used as a context manager to automatically
+    reset the variable on exit, or passed directly to :meth:`RunVar.reset`.
+    """
+
+    __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
+
+    def __enter__(self) -> RunvarToken[T]:
+        return self
+
+    def __exit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
+    ) -> None:
+        self._var.reset(self)
+
+
+class RunVar(Generic[T]):
+    """
+    Like a :class:`~contextvars.ContextVar`, except scoped to the running event loop.
+
+    Can be used as a context manager, Just like :class:`~contextvars.ContextVar`, that
+    will reset the variable to its previous value when the context block is exited.
+    """
+
+    __slots__ = "_name", "_default"
+
+    NO_VALUE_SET: Literal[_NoValueSet.NO_VALUE_SET] = _NoValueSet.NO_VALUE_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[RunVar[T], T]:
+        native_token = current_token().native_token
+        try:
+            return _run_vars[native_token]
+        except KeyError:
+            run_vars = _run_vars[native_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:
+        """
+        Return the current value of this run variable.
+
+        :param default: a fallback value to return if no value has been set
+        :return: the current value, the provided default, or the variable's own default
+        :raises LookupError: if no value is set and no default is available
+
+        """
+        try:
+            return self._current_vars[self]
+        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]:
+        """
+        Set the value of this run variable for the current event loop.
+
+        :param value: the new value
+        :return: a token that can be used to restore the previous value
+
+        """
+        current_vars = self._current_vars
+        token = RunvarToken(self, current_vars.get(self, RunVar.NO_VALUE_SET))
+        current_vars[self] = value
+        return token
+
+    def reset(self, token: RunvarToken[T]) -> None:
+        """
+        Restore this run variable to the value it held before the matching :meth:`set`.
+
+        :param token: the token returned by :meth:`set`
+        :raises ValueError: if the token belongs to a different :class:`RunVar` or the token
+            has already been used
+
+        """
+        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]
+            except KeyError:
+                pass
+        else:
+            self._current_vars[self] = token._value
+
+        token._redeemed = True
+
+    def __repr__(self) -> str:
+        return f"<RunVar name={self._name!r}>"