kern/
byte.rs

1//! Byte-level operations
2
3/// Split bytes at most n times
4pub fn splitn<D: AsRef<[u8]>>(n: usize, data: &D, seperator: impl AsRef<[u8]>) -> Vec<&[u8]> {
5    // as ref
6    let sep = seperator.as_ref();
7    let mut data = data.as_ref();
8
9    // scan for seperator position
10    let mut buf = Vec::with_capacity(n);
11    while let Some(pos) = scan(data, sep) {
12        // check if n-length reached
13        if buf.len() + 1 == n {
14            break;
15        }
16
17        // split and add to buf
18        let (split, rest) = data.split_at(pos);
19        buf.push(split);
20
21        // remove seperator
22        data = rest.split_at(sep.len()).1;
23    }
24
25    // add remaining bytes and return
26    buf.push(data);
27    buf
28}
29
30/// Split bytes
31pub fn split<D: AsRef<[u8]>>(data: &D, seperator: impl AsRef<[u8]>) -> Vec<&[u8]> {
32    // as ref
33    let sep = seperator.as_ref();
34    let mut data = data.as_ref();
35
36    // scan for seperator position
37    let mut buf = Vec::new();
38    while let Some(pos) = scan(data, sep) {
39        // split and add to buf
40        let (split, rest) = data.split_at(pos);
41        buf.push(split);
42
43        // remove seperator
44        data = rest.split_at(sep.len()).1;
45    }
46
47    // add remaining bytes and return
48    buf.push(data);
49    buf
50}
51
52/// Returns index of first byte in pattern
53pub fn scan(data: impl AsRef<[u8]>, pattern: impl AsRef<[u8]>) -> Option<usize> {
54    // as ref
55    let data: &[u8] = data.as_ref();
56    let pat: &[u8] = pattern.as_ref();
57
58    // checks
59    if pat.len() > data.len() {
60        return None;
61    }
62
63    // iterate through data bytes
64    let mut found = 0usize;
65    for (i, &d) in data.iter().enumerate() {
66        // check if pattern matches
67        if d == pat[found] {
68            // found another byte
69            found += 1;
70
71            // check if found all
72            if found == pat.len() {
73                // return index of first byte in pattern
74                return Some(i + 1 - pat.len());
75            }
76        } else {
77            // pattern interrupted
78            found = 0;
79        }
80    }
81
82    // not found
83    None
84}
kern/byte.rs

kern/
byte.rs
