Problem migrate code from tokio 0.2 to 1.20

[ghost]

error[E0432]: unresolved import `tokio::net::udp::SendHalf`
 --> src\doh\udpserver.rs:5:18
  |
5 | use tokio::net::{udp::SendHalf, UdpSocket};
  |                  ^^^^^^^^^^^^^ no `SendHalf` in `net::udp`

error[E0425]: cannot find function `delay_for` in module `tokio::time`
   --> src\doh\proxy.rs:342:26
    |
342 |             tokio::time::delay_for(timer_duration).await;
    |                          ^^^^^^^^^ not found in `tokio::time`

error[E0603]: module `udp` is private
  --> src\doh\udpserver.rs:5:18
   |
5  | use tokio::net::{udp::SendHalf, UdpSocket};
   |                  ^^^ private module
   |
note: the module `udp` is defined here
  --> C:\Users\nomore\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\tokio-1.20.0\src\net\mod.rs:39:5
   |
39 |     mod udp;
   |     ^^^^^^^^

error[E0599]: no method named `bytes` found for struct `bytes::bytes::Bytes` in the current scope
   --> src\doh\client.rs:127:29
    |
127 |         let body_vec = body.bytes().to_vec();
    |                             ^^^^^ method not found in `bytes::bytes::Bytes`
    |
    = help: items from traits can only be used if the trait is in scope
help: the following trait is implemented but not in scope; perhaps add a `use` for it:
    |
1   | use std::io::Read;
    |

warning: variable does not need to be mutable
  --> src\doh\tcpserver.rs:77:13
   |
77 |         let mut listener = TcpListener::bind(self.server_configuration.listen_address()).await?;
   |             ----^^^^^^^^
   |             |
   |             help: remove this `mut`
   |
   = note: `#[warn(unused_mut)]` on by default

error[E0599]: no method named `split` found for struct `tokio::net::UdpSocket` in the current scope
  --> src\doh\udpserver.rs:95:63
   |
95 |         let (mut socket_recv_half, socket_send_half) = socket.split();
   |                                                               ^^^^^ method not found in `tokio::net::UdpSocket`

warning: variable does not need to be mutable
  --> src\doh\udpserver.rs:35:9
   |
35 |         mut response_sender: mpsc::Sender<UDPResponseMessage>,
   |         ----^^^^^^^^^^^^^^^
   |         |
   |         help: remove this `mut`

warning: unused import: `bytes::Buf`
 --> src\doh\client.rs:5:5
  |
5 | use bytes::Buf;
  |     ^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

Some errors have detailed explanations: E0425, E0432, E0599, E0603.
For more information about an error, try `rustc --explain E0425`.
warning: `rust-doh-proxy` (bin "rust-doh-proxy") generated 3 warnings
error: could not compile `rust-doh-proxy` due to 5 previous errors; 3 warnings emitted

[ghost]

source code is here:
https://github.com/cnmade/rust-doh

[Noah-Kennedy]

The Tokio APIs changed significantly between 0.2 and 1.0, as 1.0 was when the APIs were stabilized. Please read through the API docs.

The main issues I see here are that delay_for has been replaced by sleep and that UdpSocket no longer provides a splitting API (just put it in an Arc and clone it).