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
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
extern crate tokio_codec;
extern crate tokio_io;
extern crate bytes;
extern crate futures;
use futures::{Stream, Future};
use std::io::{self, Read};
use tokio_codec::{Framed, FramedParts, Decoder, Encoder};
use tokio_io::AsyncRead;
use bytes::{BytesMut, Buf, BufMut, IntoBuf};
const INITIAL_CAPACITY: usize = 8 * 1024;
/// Encode and decode u32 values.
struct U32Codec;
impl Decoder for U32Codec {
type Item = u32;
type Error = io::Error;
fn decode(&mut self, buf: &mut BytesMut) -> io::Result<Option<u32>> {
if buf.len() < 4 {
return Ok(None);
}
let n = buf.split_to(4).into_buf().get_u32_be();
Ok(Some(n))
}
}
impl Encoder for U32Codec {
type Item = u32;
type Error = io::Error;
fn encode(&mut self, item: u32, dst: &mut BytesMut) -> io::Result<()> {
// Reserve space
dst.reserve(4);
dst.put_u32_be(item);
Ok(())
}
}
/// This value should never be used
struct DontReadIntoThis;
impl Read for DontReadIntoThis {
fn read(&mut self, _: &mut [u8]) -> io::Result<usize> {
Err(io::Error::new(io::ErrorKind::Other,
"Read into something you weren't supposed to."))
}
}
impl AsyncRead for DontReadIntoThis {}
#[test]
fn can_read_from_existing_buf() {
let mut parts = FramedParts::new(DontReadIntoThis, U32Codec);
parts.read_buf = vec![0, 0, 0, 42].into();
let framed = Framed::from_parts(parts);
let num = framed
.into_future()
.map(|(first_num, _)| {
first_num.unwrap()
})
.wait()
.map_err(|e| e.0)
.unwrap();
assert_eq!(num, 42);
}
#[test]
fn external_buf_grows_to_init() {
let mut parts = FramedParts::new(DontReadIntoThis, U32Codec);
parts.read_buf = vec![0, 0, 0, 42].into();
let framed = Framed::from_parts(parts);
let FramedParts { read_buf, .. } = framed.into_parts();
assert_eq!(read_buf.capacity(), INITIAL_CAPACITY);
}
#[test]
fn external_buf_does_not_shrink() {
let mut parts = FramedParts::new(DontReadIntoThis, U32Codec);
parts.read_buf = vec![0; INITIAL_CAPACITY * 2].into();
let framed = Framed::from_parts(parts);
let FramedParts { read_buf, .. } = framed.into_parts();
assert_eq!(read_buf.capacity(), INITIAL_CAPACITY * 2);
}
|
