Class IOStream

python/python3/tornado/iostream.py:1076–1338

r"""Socket-based `IOStream` implementation. This class supports the read and write methods from `BaseIOStream` plus a `connect` method. The ``socket`` parameter may either be connected or unconnected. For server operations the socket is the result of calling `socket.accept <soc

class IOStream(BaseIOStream):
    r"""Socket-based `IOStream` implementation.

    This class supports the read and write methods from `BaseIOStream`
    plus a `connect` method.

    The ``socket`` parameter may either be connected or unconnected.
    For server operations the socket is the result of calling
    `socket.accept <socket.socket.accept>`.  For client operations the
    socket is created with `socket.socket`, and may either be
    connected before passing it to the `IOStream` or connected with
    `IOStream.connect`.

    A very simple (and broken) HTTP client using this class:

    .. testcode::

        import tornado.ioloop
        import tornado.iostream
        import socket

        async def main():
            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
            stream = tornado.iostream.IOStream(s)
            await stream.connect(("friendfeed.com", 80))
            await stream.write(b"GET / HTTP/1.0\r\nHost: friendfeed.com\r\n\r\n")
            header_data = await stream.read_until(b"\r\n\r\n")
            headers = {}
            for line in header_data.split(b"\r\n"):
                parts = line.split(b":")
                if len(parts) == 2:
                    headers[parts[0].strip()] = parts[1].strip()
            body_data = await stream.read_bytes(int(headers[b"Content-Length"]))
            print(body_data)
            stream.close()

        if __name__ == '__main__':
            asyncio.run(main())

    .. testoutput::
       :hide:

    """

    def __init__(self, socket: socket.socket, *args: Any, **kwargs: Any) -> None:
        self.socket = socket
        self.socket.setblocking(False)
        super().__init__(*args, **kwargs)

    def fileno(self) -> Union[int, ioloop._Selectable]:
        return self.socket

    def close_fd(self) -> None:
        self.socket.close()
        self.socket = None  # type: ignore

    def get_fd_error(self) -> Optional[Exception]:
        errno = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)