asyncio/streams/
match_cond.rs

1pub trait MatchCondition : Send + 'static {
2    fn match_cond(&mut self, buf: &[u8]) -> Result<usize, usize>;
3}
4
5impl MatchCondition for usize {
6    fn match_cond(&mut self, buf: &[u8]) -> Result<usize, usize> {
7        if buf.len() >= *self {
8            Ok(*self)
9        } else {
10            *self -= buf.len();
11            Err(buf.len())
12        }
13    }
14}
15
16impl MatchCondition for u8 {
17    fn match_cond(&mut self, buf: &[u8]) -> Result<usize, usize> {
18        if let Some(len) = buf.iter().position(|&x| x == *self) {
19            Ok(len+1)
20        } else {
21            Err(buf.len())
22        }
23    }
24}
25
26impl MatchCondition for &'static [u8] {
27    fn match_cond(&mut self, buf: &[u8]) -> Result<usize, usize> {
28        let mut cur = 0;
29        if !self.is_empty() {
30            let head = self[0];
31            let tail = &self[1..];
32            let mut it = buf.iter();
33            while let Some(mut len) = it.position(|&x| x == head) {
34                len += cur + 1;
35                let buf = &buf[len..];
36                if buf.len() < tail.len() {
37                    return Err(len - 1);
38                } else if buf.starts_with(tail) {
39                    return Ok(len + tail.len());
40                }
41                cur = len;
42                it = buf.iter();
43            }
44            cur = buf.len();
45        }
46        Err(cur)
47    }
48}
49
50impl MatchCondition for char {
51    fn match_cond(&mut self, buf: &[u8]) -> Result<usize, usize> {
52        (*self as u8).match_cond(buf)
53    }
54}
55
56impl MatchCondition for &'static str {
57    fn match_cond(&mut self, buf: &[u8]) -> Result<usize, usize> {
58        self.as_bytes().match_cond(buf)
59    }
60}
61
62#[test]
63fn test_match_cond() {
64    assert!((5 as usize).match_cond("hello".as_bytes()) == Ok(5));
65    assert!((5 as usize).match_cond("hello world".as_bytes()) == Ok(5));
66    assert!((10 as usize).match_cond("hello".as_bytes()) == Err(5));
67    assert!('l'.match_cond("hello".as_bytes()) == Ok(3));
68    assert!('w'.match_cond("hello".as_bytes()) == Err(5));
69    assert!("lo".match_cond("hello world".as_bytes()) == Ok(5));
70    assert!("world!".match_cond("hello world".as_bytes()) == Err(6));
71    assert!("".match_cond("hello".as_bytes()) == Err(0));
72    assert!("l".match_cond("hello".as_bytes()) == Ok(3));
73}
asyncio/streams/match_cond.rs

asyncio/streams/
match_cond.rs
