tokio_udp/
send_dgram.rs

1use super::socket::UdpSocket;
2
3use std::io;
4use std::net::SocketAddr;
5
6use futures::{Async, Future, Poll};
7
8/// A future used to write the entire contents of some data to a UDP socket.
9///
10/// This is created by the `UdpSocket::send_dgram` method.
11#[must_use = "futures do nothing unless polled"]
12#[derive(Debug)]
13pub struct SendDgram<T> {
14    /// None means future was completed
15    state: Option<SendDgramInner<T>>,
16}
17
18/// A struct is used to represent the full info of SendDgram.
19#[derive(Debug)]
20struct SendDgramInner<T> {
21    /// Tx socket
22    socket: UdpSocket,
23    /// The whole buffer will be sent
24    buffer: T,
25    /// Destination addr
26    addr: SocketAddr,
27}
28
29impl<T> SendDgram<T> {
30    /// Create a new future to send UDP Datagram
31    pub(crate) fn new(socket: UdpSocket, buffer: T, addr: SocketAddr) -> SendDgram<T> {
32        let inner = SendDgramInner {
33            socket: socket,
34            buffer: buffer,
35            addr: addr,
36        };
37        SendDgram { state: Some(inner) }
38    }
39}
40
41fn incomplete_write(reason: &str) -> io::Error {
42    io::Error::new(io::ErrorKind::Other, reason)
43}
44
45impl<T> Future for SendDgram<T>
46where
47    T: AsRef<[u8]>,
48{
49    type Item = (UdpSocket, T);
50    type Error = io::Error;
51
52    fn poll(&mut self) -> Poll<(UdpSocket, T), io::Error> {
53        {
54            let ref mut inner = self
55                .state
56                .as_mut()
57                .expect("SendDgram polled after completion");
58            let n = try_ready!(inner
59                .socket
60                .poll_send_to(inner.buffer.as_ref(), &inner.addr));
61            if n != inner.buffer.as_ref().len() {
62                return Err(incomplete_write(
63                    "failed to send entire message \
64                     in datagram",
65                ));
66            }
67        }
68
69        let inner = self.state.take().unwrap();
70        Ok(Async::Ready((inner.socket, inner.buffer)))
71    }
72}
tokio_udp/send_dgram.rs

tokio_udp/
send_dgram.rs
