Source code for pcapkit.protocols.misc.no_payload

# -*- coding: utf-8 -*-
"""No-Payload Packet
=======================

.. module:: pcapkit.protocols.misc.no_payload

:mod:`pcapkit.protocols.misc.no_payload` contains
:class:`~pcapkit.protocols.misc.no_payload.NoPayload` only, which
implements a :class:`~pcapkit.protocols.protocol.Protocol` like
object whose payload is
:class:`~pcapkit.protocols.misc.no_payload.NoPayload` itself.

.. versionadded:: 1.6.0

   Moved here from ``pcapkit.protocols.misc.null``, with its data model and
   header schema, since a protocol class is named after its module
   (:issue:`2529`).

.. versionremoved:: 1.6.0

   ``pcapkit.protocols.misc.null``, ``pcapkit.protocols.data.misc.null`` and
   ``pcapkit.protocols.schema.misc.null``, with no alias (:issue:`2529`).

"""
import io
from typing import TYPE_CHECKING, overload

from pcapkit.protocols.data.misc.no_payload import NoPayload as Data_NoPayload
from pcapkit.protocols.protocol import ProtocolBase
from pcapkit.protocols.schema.misc.no_payload import NoPayload as Schema_NoPayload
from pcapkit.utilities.exceptions import UnsupportedCall

if TYPE_CHECKING:
    from typing import IO, Any, NoReturn, Optional

    from typing_extensions import Literal

__all__ = ['NoPayload']




class NoPayload(ProtocolBase[Data_NoPayload, Schema_NoPayload],
                schema=Schema_NoPayload, data=Data_NoPayload):
    """This class implements no-payload protocol.

    Its ``payload`` is the instance itself, so a ``.payload`` walk over it
    never terminates; bound any such loop, or walk the protocol chain of
    the enclosing packet instead.

    """

    ##########################################################################
    # Properties.
    ##########################################################################

    # name of current protocol
    @property
    def name(self) -> 'Literal["Null"]':
        """Name of current protocol."""
        return 'Null'

    # header length of current protocol
    @property
    def length(self) -> 'Literal[0]':
        """Header length of current protocol."""
        return 0

    # name of next layer protocol
    @property
    def protocol(self) -> 'NoReturn':
        """Name of next layer protocol.

        Raises:
            UnsupportedCall: This protocol doesn't support :attr:`protocol`.

        """
        raise UnsupportedCall(f"'{self.__class__.__name__}' object has no attribute 'protocol'")

    # protocol chain of current instance
    @property
    def protochain(self) -> 'None':  # type: ignore[override]
        """Protocol chain of current instance, which an empty payload does not
        have.

        .. versionchanged:: 1.5.0

           Narrows :attr:`Protocol.protochain
           <pcapkit.protocols.protocol.Protocol.protochain>`'s declared
           type from :class:`~pcapkit.corekit.protochain.ProtoChain` to
           :obj:`None`, the value ``self._protos`` already held here; the fix
           is to the declaration, not the runtime value (:issue:`2317`).

        """
        return None

    ##########################################################################
    # Methods.
    ##########################################################################



    def read(self, length: 'Optional[int]' = None, **kwargs: 'Any') -> 'Data_NoPayload':  # pylint: disable=unused-argument
        """Read (parse) packet data.

        Args:
            length: Length of packet data.
            **kwargs: Arbitrary keyword arguments.

        Returns:
            Parsed packet data.

        """
        return Data_NoPayload()




    def make(self, **kwargs: 'Any') -> 'Schema_NoPayload':
        """Make (construct) packet data.

        Args:
            **kwargs: Arbitrary keyword arguments.

        Returns:
            Constructed packet schema.

        """
        return Schema_NoPayload()


    ##########################################################################
    # Data models.
    ##########################################################################

    @overload
    def __post_init__(self, file: 'IO[bytes] | bytes', length: 'Optional[int]' = ..., **kwargs: 'Any') -> 'None': ...
    @overload
    def __post_init__(self, **kwargs: 'Any') -> 'None': ...  # pylint: disable=arguments-differ



    def __post_init__(self, file: 'Optional[IO[bytes] | bytes]' = None,  # pylint: disable=unused-argument
                      length: 'Optional[int]' = None, **kwargs: 'Any') -> 'None':
        """Post initialisation hook.

        Args:
            file: Source packet stream.
            length: Length of packet data.
            **kwargs: Arbitrary keyword arguments.

        """
        #: bytes: Raw packet data.
        self._data = b''
        #: io.BytesIO: Source data stream.
        self._file = io.BytesIO()
        #: pcapkit.protocols.data.misc.no_payload.NoPayload: Data model of current instance.
        self._info = Data_NoPayload()

        #: pcapkit.protocols.misc.no_payload.NoPayload: Payload of current instance.
        self._next = self
        #: None: Protocol chain of current instance, which an empty payload
        #: does not have.
        self._protos = None  # type: ignore[assignment]




    @classmethod
    def __index__(cls) -> 'NoReturn':
        """Numeral registry index of the protocol.

        Raises:
            UnsupportedCall: This protocol has no registry entry.

        """
        raise UnsupportedCall(f'{cls.__name__!r} object cannot be interpreted as an integer')