def decode_frame(data_in):
    """Receives raw socket data and attempts to turn it into a frame.
    Returns bytes used to make the frame and the frame

    :param str data_in: The raw data stream
    :rtype: tuple(bytes consumed, frame)
    :raises: pika.exceptions.InvalidFrameError

    """
    # Look to see if it's a protocol header frame
    try:
        if data_in[0:4] == b'AMQP':
            major, minor, revision = struct.unpack_from('BBB', data_in, 5)
            return 8, ProtocolHeader(major, minor, revision)
    except (IndexError, struct.error):
        return 0, None

    # Get the Frame Type, Channel Number and Frame Size
    try:
        (frame_type, channel_number,
         frame_size) = struct.unpack('>BHL', data_in[0:7])
    except struct.error:
        return 0, None

    # Get the frame data
    frame_end = spec.FRAME_HEADER_SIZE + frame_size + spec.FRAME_END_SIZE

    # We don't have all of the frame yet
    if frame_end > len(data_in):
        return 0, None

    # The Frame termination chr is wrong
    if data_in[frame_end - 1:frame_end] != byte(spec.FRAME_END):
        raise exceptions.InvalidFrameError("Invalid FRAME_END marker")

    # Get the raw frame data
    frame_data = data_in[spec.FRAME_HEADER_SIZE:frame_end - 1]

    if frame_type == spec.FRAME_METHOD:

        # Get the Method ID from the frame data
        method_id = struct.unpack_from('>I', frame_data)[0]

        # Get a Method object for this method_id
        method = spec.methods[method_id]()

        # Decode the content
        method.decode(frame_data, 4)

        # Return the amount of data consumed and the Method object
        return frame_end, Method(channel_number, method)

    elif frame_type == spec.FRAME_HEADER:

        # Return the header class and body size
        class_id, weight, body_size = struct.unpack_from('>HHQ', frame_data)

        # Get the Properties type
        properties = spec.props[class_id]()

        # Decode the properties
        out = properties.decode(frame_data[12:])

        # Return a Header frame
        return frame_end, Header(channel_number, body_size, properties)

    elif frame_type == spec.FRAME_BODY:

        # Return the amount of data consumed and the Body frame w/ data
        return frame_end, Body(channel_number, frame_data)

    elif frame_type == spec.FRAME_HEARTBEAT:

        # Return the amount of data and a Heartbeat frame
        return frame_end, Heartbeat()

    raise exceptions.InvalidFrameError("Unknown frame type: %i" % frame_type)
dataset/ETHPy150Open pika/pika/pika/frame.py/decode_frame/original