Source code for httk.core.datastream.bytestream_bytes

import io
from typing import Any, Self

from .bytestream_backend import BytestreamBackend
from .bytestream_common import BytestreamCommon
from .compression import open_compressed, validate_compression




class BytestreamBytes(BytestreamCommon, BytestreamBackend):
    r"""
    Backend for streaming byte data backed by an actual bytes object.
    Compressed content is transparently decompressed according to the compression hint.

    :param content: Bytes to expose as a stream.
    :param \**hints: Backend-selection and compression hints.
    :raises ValueError: If the compression hint is unknown.
    """



    b: bytes

    _compression: str
    _f: io.IOBase | None
    _underlying: io.IOBase | None
    _closed: bool

    @classmethod
    def _backend_adopt(cls, obj: Any, **hints: Any) -> Self | None:
        r"""Adopt byte content when it matches this backend.

        :param obj: The object to adopt.
        :param \**hints: Backend-selection and compression hints.
        :return: An initialized backend, or ``None`` when ``obj`` is not accepted.
        """
        if not isinstance(obj, bytes | bytearray):
            return None
        if hints and hints.get("kind", "content") != "content":
            return None
        return cls(obj, **hints)

    def __init__(self, content: bytes | bytearray, **hints: Any) -> None:
        self.b = bytes(content)
        self._compression = hints.get("compression", "auto")
        validate_compression(self._compression)
        self._f = None
        self._underlying = None
        self._closed = False

    def _ensure_f(self) -> io.IOBase:
        if self._closed:
            raise ValueError("I/O operation on closed stream")
        if self._f is None:
            raw: io.IOBase = io.BytesIO(self.b)
            opened = open_compressed(raw, compression=self._compression, name=None)
            self._underlying = raw if opened is not raw else None
            self._f = opened
        return self._f

    @property


    def name(self) -> str | None:
        """Report that an in-memory stream has no source name."""
        return None


    @property


    def closed(self) -> bool:
        """Report whether the in-memory stream is closed."""
        return self._closed