ruyi 0.1.6

An event-driven framework for non-blocking, asynchronous I/O in Rust
Documentation 
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
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135

use std::io;

use futures::{Async, Poll, Stream};

use buf::ByteBuf;
use buf::codec::u8;

enum State {
    More(usize),
    Pending,
    Done,
}

pub struct U8Prefix<S> {
    stream: S,
    state: State,
    data: ByteBuf,
}

impl<S> U8Prefix<S> {
    #[inline]
    fn new(stream: S) -> Self {
        U8Prefix {
            stream,
            state: State::Pending,
            data: ByteBuf::new(),
        }
    }

    #[inline]
    pub fn get_ref(&self) -> &S {
        &self.stream
    }

    #[inline]
    pub fn get_mut(&mut self) -> &mut S {
        &mut self.stream
    }

    #[inline]
    pub fn into_inner(self) -> S {
        self.stream
    }
}

impl<S> U8Prefix<S>
where
    S: Stream<Item = ByteBuf, Error = io::Error>,
{
    #[inline]
    fn poll_more(&mut self, n: usize) -> Poll<Option<ByteBuf>, io::Error> {
        match try_ready!(self.stream.poll()) {
            Some(pulled) => {
                self.data.extend(pulled);
                match self.data.drain_to(n) {
                    Ok(t) => {
                        self.state = State::Pending;
                        Ok(Async::Ready(Some(t)))
                    }
                    Err(..) => Ok(Async::NotReady),
                }
            }
            None => {
                self.state = State::Done;
                Ok(Async::Ready(None))
            }
        }
    }

    #[inline]
    fn poll_pending(&mut self) -> Poll<Option<ByteBuf>, io::Error> {
        match try_ready!(self.stream.poll()) {
            Some(pulled) => {
                self.data = pulled;
                match self.data.read(u8::read) {
                    Ok(n) => {
                        match self.data.drain_to(n as usize) {
                            Ok(t) => Ok(Async::Ready(Some(t))),
                            Err(..) => {
                                // data.len() < n
                                self.state = State::More(n as usize);
                                Ok(Async::NotReady)
                            }
                        }
                    }
                    Err(..) => Ok(Async::NotReady),
                }
            }
            None => {
                self.state = State::Done;
                Ok(Async::Ready(None))
            }
        }
    }
}

impl<S> Stream for U8Prefix<S>
where
    S: Stream<Item = ByteBuf, Error = io::Error>,
{
    type Item = ByteBuf;
    type Error = io::Error;

    fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
        match self.state {
            State::Pending => {
                match self.data.read(u8::read) {
                    Ok(n) => {
                        match self.data.drain_to(n as usize) {
                            Ok(t) => Ok(Async::Ready(Some(t))),
                            Err(..) => {
                                // data.len() < n
                                self.state = State::More(n as usize);
                                self.poll_more(n as usize)
                            }
                        }
                    }
                    Err(..) => self.poll_pending(),
                }
            }
            State::More(n) => self.poll_more(n),
            State::Done => Ok(Async::Ready(None)),
        }
    }
}

impl<S> From<S> for U8Prefix<S>
where
    S: Stream<Item = ByteBuf, Error = io::Error>,
{
    #[inline]
    fn from(stream: S) -> Self {
        Self::new(stream)
    }
}