1 | /// A wrapper around a slice that exposes no functions that can panic. |
2 | /// |
3 | /// Intentionally avoids implementing `Debug`, `Eq`, and `PartialEq` to avoid |
4 | /// creating a side channel that would leak information about the value. |
5 | #[derive (Clone, Copy)] |
6 | pub struct Slice<'a> { |
7 | bytes: &'a [u8], |
8 | } |
9 | |
10 | impl<'a> Slice<'a> { |
11 | #[inline ] |
12 | pub const fn new(bytes: &'a [u8]) -> Self { |
13 | Self { bytes } |
14 | } |
15 | |
16 | #[inline ] |
17 | pub fn get(&self, i: usize) -> Option<&u8> { |
18 | self.bytes.get(i) |
19 | } |
20 | |
21 | #[inline ] |
22 | pub fn subslice(&self, r: core::ops::Range<usize>) -> Option<Self> { |
23 | self.bytes.get(r).map(|bytes| Self { bytes }) |
24 | } |
25 | |
26 | #[inline ] |
27 | pub fn is_empty(&self) -> bool { |
28 | self.bytes.is_empty() |
29 | } |
30 | |
31 | #[inline ] |
32 | pub fn len(&self) -> usize { |
33 | self.bytes.len() |
34 | } |
35 | |
36 | #[inline ] |
37 | pub fn as_slice_less_safe(&self) -> &'a [u8] { |
38 | self.bytes |
39 | } |
40 | } |
41 | |