一处处理重复性错误案例

Question

I'm writing a function which writes a struct of multiple fields to a TCP connection. Is there a way to handle errors in one place like catching exception in Java?

My implementation looks like,

func writeFrame(frame *Frame, conn net.Conn) error {
    bo := binary.BigEndian
    if err := binary.Write(conn, bo, frame.ype); err != nil {
        return err
    }
    if err := binary.Write(conn, bo, frame.id); err != nil {
        return err
    }
    if err := binary.Write(conn, bo, frame.seq); err != nil {
        return err
    }

    if err := binary.Write(conn, bo, uint32(len(frame.arg1))); err != nil {
        return err
    }
    if err := binary.Write(conn, bo, uint32(len(frame.arg2))); err != nil {
        return err
    }
    if err := binary.Write(conn, bo, uint32(len(frame.arg3))); err != nil {
        return err
    }

    var csum uint32
    if err := binary.Write(conn, bo, csum); err != nil {
        return err
    }

    if _, err := conn.Write(frame.arg1); err != nil {
        return err
    }
    if _, err := conn.Write(frame.arg2); err != nil {
        return err
    }
    if _, err := conn.Write(frame.arg3); err != nil {
        return err
    }
    return nil
}

Answer 1

You can use a bufio.Writer for this. If any error occurs future Write's will simply return the same error and be ignored.

func writeFrame(frame *Frame, conn net.Conn) error {
    bo := binary.BigEndian

    w := bufio.NewWriter(conn)

    binary.Write(w, bo, frame.ype)
    binary.Write(w, bo, frame.id)
    binary.Write(w, bo, frame.seq)

    binary.Write(w, bo, uint32(len(frame.arg1)))
    binary.Write(w, bo, uint32(len(frame.arg2)))
    binary.Write(w, bo, uint32(len(frame.arg3)))

    var csum uint32
    binary.Write(w, bo, csum)

    w.Write(frame.arg1)
    w.Write(frame.arg2)
    w.Write(frame.arg3)

    // Write outstanding data to conn and return an error if any occured
    return w.Flush()
}