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Diffstat (limited to 'venv/lib/python3.11/site-packages/anyio/streams/file.py')
-rw-r--r-- | venv/lib/python3.11/site-packages/anyio/streams/file.py | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/venv/lib/python3.11/site-packages/anyio/streams/file.py b/venv/lib/python3.11/site-packages/anyio/streams/file.py new file mode 100644 index 0000000..f492464 --- /dev/null +++ b/venv/lib/python3.11/site-packages/anyio/streams/file.py @@ -0,0 +1,148 @@ +from __future__ import annotations + +from collections.abc import Callable, Mapping +from io import SEEK_SET, UnsupportedOperation +from os import PathLike +from pathlib import Path +from typing import Any, BinaryIO, cast + +from .. import ( + BrokenResourceError, + ClosedResourceError, + EndOfStream, + TypedAttributeSet, + to_thread, + typed_attribute, +) +from ..abc import ByteReceiveStream, ByteSendStream + + +class FileStreamAttribute(TypedAttributeSet): + #: the open file descriptor + file: BinaryIO = typed_attribute() + #: the path of the file on the file system, if available (file must be a real file) + path: Path = typed_attribute() + #: the file number, if available (file must be a real file or a TTY) + fileno: int = typed_attribute() + + +class _BaseFileStream: + def __init__(self, file: BinaryIO): + self._file = file + + async def aclose(self) -> None: + await to_thread.run_sync(self._file.close) + + @property + def extra_attributes(self) -> Mapping[Any, Callable[[], Any]]: + attributes: dict[Any, Callable[[], Any]] = { + FileStreamAttribute.file: lambda: self._file, + } + + if hasattr(self._file, "name"): + attributes[FileStreamAttribute.path] = lambda: Path(self._file.name) + + try: + self._file.fileno() + except UnsupportedOperation: + pass + else: + attributes[FileStreamAttribute.fileno] = lambda: self._file.fileno() + + return attributes + + +class FileReadStream(_BaseFileStream, ByteReceiveStream): + """ + A byte stream that reads from a file in the file system. + + :param file: a file that has been opened for reading in binary mode + + .. versionadded:: 3.0 + """ + + @classmethod + async def from_path(cls, path: str | PathLike[str]) -> FileReadStream: + """ + Create a file read stream by opening the given file. + + :param path: path of the file to read from + + """ + file = await to_thread.run_sync(Path(path).open, "rb") + return cls(cast(BinaryIO, file)) + + async def receive(self, max_bytes: int = 65536) -> bytes: + try: + data = await to_thread.run_sync(self._file.read, max_bytes) + except ValueError: + raise ClosedResourceError from None + except OSError as exc: + raise BrokenResourceError from exc + + if data: + return data + else: + raise EndOfStream + + async def seek(self, position: int, whence: int = SEEK_SET) -> int: + """ + Seek the file to the given position. + + .. seealso:: :meth:`io.IOBase.seek` + + .. note:: Not all file descriptors are seekable. + + :param position: position to seek the file to + :param whence: controls how ``position`` is interpreted + :return: the new absolute position + :raises OSError: if the file is not seekable + + """ + return await to_thread.run_sync(self._file.seek, position, whence) + + async def tell(self) -> int: + """ + Return the current stream position. + + .. note:: Not all file descriptors are seekable. + + :return: the current absolute position + :raises OSError: if the file is not seekable + + """ + return await to_thread.run_sync(self._file.tell) + + +class FileWriteStream(_BaseFileStream, ByteSendStream): + """ + A byte stream that writes to a file in the file system. + + :param file: a file that has been opened for writing in binary mode + + .. versionadded:: 3.0 + """ + + @classmethod + async def from_path( + cls, path: str | PathLike[str], append: bool = False + ) -> FileWriteStream: + """ + Create a file write stream by opening the given file for writing. + + :param path: path of the file to write to + :param append: if ``True``, open the file for appending; if ``False``, any + existing file at the given path will be truncated + + """ + mode = "ab" if append else "wb" + file = await to_thread.run_sync(Path(path).open, mode) + return cls(cast(BinaryIO, file)) + + async def send(self, item: bytes) -> None: + try: + await to_thread.run_sync(self._file.write, item) + except ValueError: + raise ClosedResourceError from None + except OSError as exc: + raise BrokenResourceError from exc |