1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
#![warn(rust_2018_idioms)]
use tokio::io::{AsyncWrite, AsyncWriteExt};
use tokio_test::assert_ok;
use bytes::BytesMut;
use std::io;
use std::pin::Pin;
use std::task::{Context, Poll};
#[tokio::test]
async fn write() {
struct Wr {
buf: BytesMut,
cnt: usize,
}
impl AsyncWrite for Wr {
fn poll_write(
mut self: Pin<&mut Self>,
_cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<io::Result<usize>> {
assert_eq!(self.cnt, 0);
self.buf.extend(&buf[0..4]);
Ok(4).into()
}
fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
Ok(()).into()
}
fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
Ok(()).into()
}
}
let mut wr = Wr {
buf: BytesMut::with_capacity(64),
cnt: 0,
};
let n = assert_ok!(wr.write(b"hello world").await);
assert_eq!(n, 4);
assert_eq!(wr.buf, b"hell"[..]);
}
|
