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Diffstat (limited to '.venv/lib/python3.12/site-packages/anyio/streams/memory.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/anyio/streams/memory.py | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/anyio/streams/memory.py b/.venv/lib/python3.12/site-packages/anyio/streams/memory.py new file mode 100644 index 00000000..83bf1d97 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/anyio/streams/memory.py @@ -0,0 +1,317 @@ +from __future__ import annotations + +import warnings +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, +) +from .._core._testing import TaskInfo, get_current_task +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 + #: number of tasks blocked on :meth:`MemoryObjectSendStream.send` + tasks_waiting_send: int + #: number of tasks blocked on :meth:`MemoryObjectReceiveStream.receive` + tasks_waiting_receive: int + + +@dataclass(eq=False) +class MemoryObjectItemReceiver(Generic[T_Item]): + task_info: TaskInfo = field(init=False, default_factory=get_current_task) + item: T_Item = field(init=False) + + def __repr__(self) -> str: + # When item is not defined, we get following error with default __repr__: + # AttributeError: 'MemoryObjectItemReceiver' object has no attribute 'item' + item = getattr(self, "item", None) + return f"{self.__class__.__name__}(task_info={self.task_info}, item={item!r})" + + +@dataclass(eq=False) +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, MemoryObjectItemReceiver[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), + ) + + +@dataclass(eq=False) +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() + receiver = MemoryObjectItemReceiver[T_co]() + self._state.waiting_receivers[receive_event] = receiver + + try: + await receive_event.wait() + finally: + self._state.waiting_receivers.pop(receive_event, None) + + try: + return receiver.item + except AttributeError: + raise EndOfStream from None + + 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() + + def __del__(self) -> None: + if not self._closed: + warnings.warn( + f"Unclosed <{self.__class__.__name__} at {id(self):x}>", + ResourceWarning, + source=self, + ) + + +@dataclass(eq=False) +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) -> None: + """ + 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 + + while self._state.waiting_receivers: + receive_event, receiver = self._state.waiting_receivers.popitem(last=False) + if not receiver.task_info.has_pending_cancellation(): + receiver.item = item + receive_event.set() + return + + if len(self._state.buffer) < self._state.max_buffer_size: + self._state.buffer.append(item) + else: + raise WouldBlock + + async def send(self, item: T_contra) -> None: + """ + Send an item to the stream. + + If the buffer is full, this method blocks until there is again room in the + buffer or the item can be sent directly to a receiver. + + :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 + + """ + 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) + raise + + if send_event in self._state.waiting_senders: + del self._state.waiting_senders[send_event] + raise BrokenResourceError from None + + 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() + + def __del__(self) -> None: + if not self._closed: + warnings.warn( + f"Unclosed <{self.__class__.__name__} at {id(self):x}>", + ResourceWarning, + source=self, + ) |