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| from __future__ import annotations | |
| from collections import OrderedDict, deque | |
| from dataclasses import dataclass, field | |
| from types import TracebackType | |
| from typing import Generic, NamedTuple, TypeVar | |
| from .. import ( | |
| BrokenResourceError, | |
| ClosedResourceError, | |
| EndOfStream, | |
| WouldBlock, | |
| get_cancelled_exc_class, | |
| ) | |
| from .._core._compat import DeprecatedAwaitable | |
| from ..abc import Event, ObjectReceiveStream, ObjectSendStream | |
| from ..lowlevel import checkpoint | |
| T_Item = TypeVar("T_Item") | |
| T_co = TypeVar("T_co", covariant=True) | |
| T_contra = TypeVar("T_contra", contravariant=True) | |
| class MemoryObjectStreamStatistics(NamedTuple): | |
| current_buffer_used: int #: number of items stored in the buffer | |
| #: maximum number of items that can be stored on this stream (or :data:`math.inf`) | |
| max_buffer_size: float | |
| open_send_streams: int #: number of unclosed clones of the send stream | |
| open_receive_streams: int #: number of unclosed clones of the receive stream | |
| tasks_waiting_send: int #: number of tasks blocked on :meth:`MemoryObjectSendStream.send` | |
| #: number of tasks blocked on :meth:`MemoryObjectReceiveStream.receive` | |
| tasks_waiting_receive: int | |
| class MemoryObjectStreamState(Generic[T_Item]): | |
| max_buffer_size: float = field() | |
| buffer: deque[T_Item] = field(init=False, default_factory=deque) | |
| open_send_channels: int = field(init=False, default=0) | |
| open_receive_channels: int = field(init=False, default=0) | |
| waiting_receivers: OrderedDict[Event, list[T_Item]] = field( | |
| init=False, default_factory=OrderedDict | |
| ) | |
| waiting_senders: OrderedDict[Event, T_Item] = field( | |
| init=False, default_factory=OrderedDict | |
| ) | |
| def statistics(self) -> MemoryObjectStreamStatistics: | |
| return MemoryObjectStreamStatistics( | |
| len(self.buffer), | |
| self.max_buffer_size, | |
| self.open_send_channels, | |
| self.open_receive_channels, | |
| len(self.waiting_senders), | |
| len(self.waiting_receivers), | |
| ) | |
| class MemoryObjectReceiveStream(Generic[T_co], ObjectReceiveStream[T_co]): | |
| _state: MemoryObjectStreamState[T_co] | |
| _closed: bool = field(init=False, default=False) | |
| def __post_init__(self) -> None: | |
| self._state.open_receive_channels += 1 | |
| def receive_nowait(self) -> T_co: | |
| """ | |
| Receive the next item if it can be done without waiting. | |
| :return: the received item | |
| :raises ~anyio.ClosedResourceError: if this send stream has been closed | |
| :raises ~anyio.EndOfStream: if the buffer is empty and this stream has been | |
| closed from the sending end | |
| :raises ~anyio.WouldBlock: if there are no items in the buffer and no tasks | |
| waiting to send | |
| """ | |
| if self._closed: | |
| raise ClosedResourceError | |
| if self._state.waiting_senders: | |
| # Get the item from the next sender | |
| send_event, item = self._state.waiting_senders.popitem(last=False) | |
| self._state.buffer.append(item) | |
| send_event.set() | |
| if self._state.buffer: | |
| return self._state.buffer.popleft() | |
| elif not self._state.open_send_channels: | |
| raise EndOfStream | |
| raise WouldBlock | |
| async def receive(self) -> T_co: | |
| await checkpoint() | |
| try: | |
| return self.receive_nowait() | |
| except WouldBlock: | |
| # Add ourselves in the queue | |
| receive_event = Event() | |
| container: list[T_co] = [] | |
| self._state.waiting_receivers[receive_event] = container | |
| try: | |
| await receive_event.wait() | |
| except get_cancelled_exc_class(): | |
| # Ignore the immediate cancellation if we already received an item, so as not to | |
| # lose it | |
| if not container: | |
| raise | |
| finally: | |
| self._state.waiting_receivers.pop(receive_event, None) | |
| if container: | |
| return container[0] | |
| else: | |
| raise EndOfStream | |
| def clone(self) -> MemoryObjectReceiveStream[T_co]: | |
| """ | |
| Create a clone of this receive stream. | |
| Each clone can be closed separately. Only when all clones have been closed will the | |
| receiving end of the memory stream be considered closed by the sending ends. | |
| :return: the cloned stream | |
| """ | |
| if self._closed: | |
| raise ClosedResourceError | |
| return MemoryObjectReceiveStream(_state=self._state) | |
| def close(self) -> None: | |
| """ | |
| Close the stream. | |
| This works the exact same way as :meth:`aclose`, but is provided as a special case for the | |
| benefit of synchronous callbacks. | |
| """ | |
| if not self._closed: | |
| self._closed = True | |
| self._state.open_receive_channels -= 1 | |
| if self._state.open_receive_channels == 0: | |
| send_events = list(self._state.waiting_senders.keys()) | |
| for event in send_events: | |
| event.set() | |
| async def aclose(self) -> None: | |
| self.close() | |
| def statistics(self) -> MemoryObjectStreamStatistics: | |
| """ | |
| Return statistics about the current state of this stream. | |
| .. versionadded:: 3.0 | |
| """ | |
| return self._state.statistics() | |
| def __enter__(self) -> MemoryObjectReceiveStream[T_co]: | |
| return self | |
| def __exit__( | |
| self, | |
| exc_type: type[BaseException] | None, | |
| exc_val: BaseException | None, | |
| exc_tb: TracebackType | None, | |
| ) -> None: | |
| self.close() | |
| class MemoryObjectSendStream(Generic[T_contra], ObjectSendStream[T_contra]): | |
| _state: MemoryObjectStreamState[T_contra] | |
| _closed: bool = field(init=False, default=False) | |
| def __post_init__(self) -> None: | |
| self._state.open_send_channels += 1 | |
| def send_nowait(self, item: T_contra) -> DeprecatedAwaitable: | |
| """ | |
| Send an item immediately if it can be done without waiting. | |
| :param item: the item to send | |
| :raises ~anyio.ClosedResourceError: if this send stream has been closed | |
| :raises ~anyio.BrokenResourceError: if the stream has been closed from the | |
| receiving end | |
| :raises ~anyio.WouldBlock: if the buffer is full and there are no tasks waiting | |
| to receive | |
| """ | |
| if self._closed: | |
| raise ClosedResourceError | |
| if not self._state.open_receive_channels: | |
| raise BrokenResourceError | |
| if self._state.waiting_receivers: | |
| receive_event, container = self._state.waiting_receivers.popitem(last=False) | |
| container.append(item) | |
| receive_event.set() | |
| elif len(self._state.buffer) < self._state.max_buffer_size: | |
| self._state.buffer.append(item) | |
| else: | |
| raise WouldBlock | |
| return DeprecatedAwaitable(self.send_nowait) | |
| async def send(self, item: T_contra) -> None: | |
| await checkpoint() | |
| try: | |
| self.send_nowait(item) | |
| except WouldBlock: | |
| # Wait until there's someone on the receiving end | |
| send_event = Event() | |
| self._state.waiting_senders[send_event] = item | |
| try: | |
| await send_event.wait() | |
| except BaseException: | |
| self._state.waiting_senders.pop(send_event, None) # type: ignore[arg-type] | |
| raise | |
| if self._state.waiting_senders.pop(send_event, None): # type: ignore[arg-type] | |
| raise BrokenResourceError | |
| def clone(self) -> MemoryObjectSendStream[T_contra]: | |
| """ | |
| Create a clone of this send stream. | |
| Each clone can be closed separately. Only when all clones have been closed will the | |
| sending end of the memory stream be considered closed by the receiving ends. | |
| :return: the cloned stream | |
| """ | |
| if self._closed: | |
| raise ClosedResourceError | |
| return MemoryObjectSendStream(_state=self._state) | |
| def close(self) -> None: | |
| """ | |
| Close the stream. | |
| This works the exact same way as :meth:`aclose`, but is provided as a special case for the | |
| benefit of synchronous callbacks. | |
| """ | |
| if not self._closed: | |
| self._closed = True | |
| self._state.open_send_channels -= 1 | |
| if self._state.open_send_channels == 0: | |
| receive_events = list(self._state.waiting_receivers.keys()) | |
| self._state.waiting_receivers.clear() | |
| for event in receive_events: | |
| event.set() | |
| async def aclose(self) -> None: | |
| self.close() | |
| def statistics(self) -> MemoryObjectStreamStatistics: | |
| """ | |
| Return statistics about the current state of this stream. | |
| .. versionadded:: 3.0 | |
| """ | |
| return self._state.statistics() | |
| def __enter__(self) -> MemoryObjectSendStream[T_contra]: | |
| return self | |
| def __exit__( | |
| self, | |
| exc_type: type[BaseException] | None, | |
| exc_val: BaseException | None, | |
| exc_tb: TracebackType | None, | |
| ) -> None: | |
| self.close() | |