Rust Programming By Example

Handling commands

To handle the commands received by the FTP server, we'll have a Client struct:

type Writer = SplitSink<Framed<TcpStream, FtpCodec>>;

struct Client {
    writer: Writer,
}

The client contains a Writer object that will be useful to send messages to the client. The Writer type represents a Sink that has been split, and uses the FtpCodec on a TcpStream. A Sink is the opposite of a Stream: instead of representing a sequence of values that are received, it represents a sequence of values that are sent.

We used two methods on Client, so let's write them:

use cmd::Command;

impl Client {
    fn new(writer: Writer) -> Client {
        Client {
            writer,
        }
    }

    #[async]
    fn handle_cmd(mut self, cmd: Command) -> Result<Self> {
        Ok(self)
    }
}

The constructor ...