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
|
use regex_automata::util::prefilter::{self, Candidate, Prefilter};
#[derive(Clone, Debug)]
pub struct SubstringPrefilter(bstr::Finder<'static>);
impl SubstringPrefilter {
pub fn new<B: AsRef<[u8]>>(needle: B) -> SubstringPrefilter {
SubstringPrefilter(bstr::Finder::new(needle.as_ref()).into_owned())
}
}
impl Prefilter for SubstringPrefilter {
#[inline]
fn next_candidate(
&self,
state: &mut prefilter::State,
haystack: &[u8],
at: usize,
) -> Candidate {
self.0
.find(&haystack[at..])
.map(|i| Candidate::PossibleStartOfMatch(at + i))
.unwrap_or(Candidate::None)
}
fn heap_bytes(&self) -> usize {
self.0.needle().len()
}
}
/// A prefilter that always returns `Candidate::None`, even if it's a false
/// negative. This is useful for confirming that a prefilter is actually
/// active by asserting an incorrect result.
#[derive(Clone, Debug)]
pub struct BunkPrefilter(());
impl BunkPrefilter {
pub fn new() -> BunkPrefilter {
BunkPrefilter(())
}
}
impl Prefilter for BunkPrefilter {
#[inline]
fn next_candidate(
&self,
_state: &mut prefilter::State,
_haystack: &[u8],
_at: usize,
) -> Candidate {
Candidate::None
}
fn heap_bytes(&self) -> usize {
0
}
}
|
