Method from_bytes

exir/_serialize/_program.py:195–230

Tries to read an extended header from the provided data. Does not validate that the header is well-formed. Callers should use is_valid(). Args: data: The data to read from. Returns: The contents of the extended header. Raises:

(data: bytes)

    @staticmethod
    def from_bytes(data: bytes) -> "_ExtendedHeader":
        """Tries to read an extended header from the provided data.

        Does not validate that the header is well-formed. Callers should
        use is_valid().

        Args:
            data: The data to read from.
        Returns:
            The contents of the extended header.
        Raises:
            ValueError: If not enough data is provided.
        """
        if len(data) < _ExtendedHeader.EXPECTED_LENGTH:
            raise ValueError(
                f"Not enough data for extended header: {len(data)} "
                + f"< {_ExtendedHeader.EXPECTED_LENGTH}"
            )

        magic = data[0:4]
        length = int.from_bytes(data[4:8], byteorder=_HEADER_BYTEORDER)
        program_size = int.from_bytes(data[8:16], byteorder=_HEADER_BYTEORDER)
        segment_base_offset = int.from_bytes(data[16:24], byteorder=_HEADER_BYTEORDER)
        segment_data_size = (
            int.from_bytes(data[24:32], byteorder=_HEADER_BYTEORDER)
            if length > _ExtendedHeader.MINIMUM_LENGTH
            else 0
        )

        return _ExtendedHeader(
            magic=magic,
            length=length,
            program_size=program_size,
            segment_base_offset=segment_base_offset,
            segment_data_size=segment_data_size,
        )

    def is_valid(self) -> bool:
        """Returns true if the extended header appears to be well-formed."""