/rust/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.42.0/src/util/memchr.rs
Line | Count | Source (jump to first uncovered line) |
1 | | //! Search for a byte in a byte array using libc. |
2 | | //! |
3 | | //! When nothing pulls in libc, then just use a trivial implementation. Note |
4 | | //! that we only depend on libc on unix. |
5 | | |
6 | | #[cfg(not(all(unix, feature = "libc")))] |
7 | | pub(crate) fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> { |
8 | | haystack.iter().position(|val| needle == *val) |
9 | | } |
10 | | |
11 | | #[cfg(all(unix, feature = "libc"))] |
12 | 0 | pub(crate) fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> { |
13 | 0 | let start = haystack.as_ptr(); |
14 | 0 |
|
15 | 0 | // SAFETY: `start` is valid for `haystack.len()` bytes. |
16 | 0 | let ptr = unsafe { libc::memchr(start.cast(), needle as _, haystack.len()) }; |
17 | 0 |
|
18 | 0 | if ptr.is_null() { |
19 | 0 | None |
20 | | } else { |
21 | 0 | Some(ptr as usize - start as usize) |
22 | | } |
23 | 0 | } Unexecuted instantiation: tokio::util::memchr::memchr Unexecuted instantiation: tokio::util::memchr::memchr Unexecuted instantiation: tokio::util::memchr::memchr Unexecuted instantiation: tokio::util::memchr::memchr Unexecuted instantiation: tokio::util::memchr::memchr |
24 | | |
25 | | #[cfg(test)] |
26 | | mod tests { |
27 | | use super::memchr; |
28 | | |
29 | | #[test] |
30 | | fn memchr_test() { |
31 | | let haystack = b"123abc456\0\xffabc\n"; |
32 | | |
33 | | assert_eq!(memchr(b'1', haystack), Some(0)); |
34 | | assert_eq!(memchr(b'2', haystack), Some(1)); |
35 | | assert_eq!(memchr(b'3', haystack), Some(2)); |
36 | | assert_eq!(memchr(b'4', haystack), Some(6)); |
37 | | assert_eq!(memchr(b'5', haystack), Some(7)); |
38 | | assert_eq!(memchr(b'6', haystack), Some(8)); |
39 | | assert_eq!(memchr(b'7', haystack), None); |
40 | | assert_eq!(memchr(b'a', haystack), Some(3)); |
41 | | assert_eq!(memchr(b'b', haystack), Some(4)); |
42 | | assert_eq!(memchr(b'c', haystack), Some(5)); |
43 | | assert_eq!(memchr(b'd', haystack), None); |
44 | | assert_eq!(memchr(b'A', haystack), None); |
45 | | assert_eq!(memchr(0, haystack), Some(9)); |
46 | | assert_eq!(memchr(0xff, haystack), Some(10)); |
47 | | assert_eq!(memchr(0xfe, haystack), None); |
48 | | assert_eq!(memchr(1, haystack), None); |
49 | | assert_eq!(memchr(b'\n', haystack), Some(14)); |
50 | | assert_eq!(memchr(b'\r', haystack), None); |
51 | | } |
52 | | |
53 | | #[test] |
54 | | fn memchr_all() { |
55 | | let mut arr = Vec::new(); |
56 | | for b in 0..=255 { |
57 | | arr.push(b); |
58 | | } |
59 | | for b in 0..=255 { |
60 | | assert_eq!(memchr(b, &arr), Some(b as usize)); |
61 | | } |
62 | | arr.reverse(); |
63 | | for b in 0..=255 { |
64 | | assert_eq!(memchr(b, &arr), Some(255 - b as usize)); |
65 | | } |
66 | | } |
67 | | |
68 | | #[test] |
69 | | fn memchr_empty() { |
70 | | for b in 0..=255 { |
71 | | assert_eq!(memchr(b, b""), None); |
72 | | } |
73 | | } |
74 | | } |