tcpclient.py 文件源码

def connect(self, host, port, af=socket.AF_UNSPEC, ssl_options=None,
                max_buffer_size=None):
        """Connect to the given host and port.

        Asynchronously returns an `.IOStream` (or `.SSLIOStream` if
        ``ssl_options`` is not None).
        """
        addrinfo = yield self.resolver.resolve(host, port, af)
        connector = _Connector(
            addrinfo, self.io_loop,
            functools.partial(self._create_stream, max_buffer_size))
        af, addr, stream = yield connector.start()
        # TODO: For better performance we could cache the (af, addr)
        # information here and re-use it on subsequent connections to
        # the same host. (http://tools.ietf.org/html/rfc6555#section-4.2)
        if ssl_options is not None:
            stream = yield stream.start_tls(False, ssl_options=ssl_options,
                                            server_hostname=host)
        raise gen.Return(stream)