/rust/registry/src/index.crates.io-6f17d22bba15001f/der-0.7.10/src/str_ref.rs
Line | Count | Source (jump to first uncovered line) |
1 | | //! Common handling for types backed by `str` slices with enforcement of a |
2 | | //! library-level length limitation i.e. `Length::max()`. |
3 | | |
4 | | use crate::{BytesRef, DecodeValue, EncodeValue, Header, Length, Reader, Result, Writer}; |
5 | | use core::str; |
6 | | |
7 | | /// String slice newtype which respects the [`Length::max`] limit. |
8 | | #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)] |
9 | | pub struct StrRef<'a> { |
10 | | /// Inner value |
11 | | pub(crate) inner: &'a str, |
12 | | |
13 | | /// Precomputed `Length` (avoids possible panicking conversions) |
14 | | pub(crate) length: Length, |
15 | | } |
16 | | |
17 | | impl<'a> StrRef<'a> { |
18 | | /// Create a new [`StrRef`], ensuring that the byte representation of |
19 | | /// the provided `str` value is shorter than `Length::max()`. |
20 | 0 | pub fn new(s: &'a str) -> Result<Self> { |
21 | 0 | Ok(Self { |
22 | 0 | inner: s, |
23 | 0 | length: Length::try_from(s.as_bytes().len())?, |
24 | | }) |
25 | 0 | } |
26 | | |
27 | | /// Parse a [`StrRef`] from UTF-8 encoded bytes. |
28 | 0 | pub fn from_bytes(bytes: &'a [u8]) -> Result<Self> { |
29 | 0 | Self::new(str::from_utf8(bytes)?) |
30 | 0 | } |
31 | | |
32 | | /// Borrow the inner `str` |
33 | 0 | pub fn as_str(&self) -> &'a str { |
34 | 0 | self.inner |
35 | 0 | } |
36 | | |
37 | | /// Borrow the inner byte slice |
38 | 0 | pub fn as_bytes(&self) -> &'a [u8] { |
39 | 0 | self.inner.as_bytes() |
40 | 0 | } |
41 | | |
42 | | /// Get the [`Length`] of this [`StrRef`] |
43 | 0 | pub fn len(self) -> Length { |
44 | 0 | self.length |
45 | 0 | } |
46 | | |
47 | | /// Is this [`StrRef`] empty? |
48 | 0 | pub fn is_empty(self) -> bool { |
49 | 0 | self.len() == Length::ZERO |
50 | 0 | } |
51 | | } |
52 | | |
53 | | impl AsRef<str> for StrRef<'_> { |
54 | 0 | fn as_ref(&self) -> &str { |
55 | 0 | self.as_str() |
56 | 0 | } |
57 | | } |
58 | | |
59 | | impl AsRef<[u8]> for StrRef<'_> { |
60 | 0 | fn as_ref(&self) -> &[u8] { |
61 | 0 | self.as_bytes() |
62 | 0 | } |
63 | | } |
64 | | |
65 | | impl<'a> DecodeValue<'a> for StrRef<'a> { |
66 | 0 | fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self> { |
67 | 0 | Self::from_bytes(BytesRef::decode_value(reader, header)?.as_slice()) |
68 | 0 | } |
69 | | } |
70 | | |
71 | | impl<'a> EncodeValue for StrRef<'a> { |
72 | 0 | fn value_len(&self) -> Result<Length> { |
73 | 0 | Ok(self.length) |
74 | 0 | } |
75 | | |
76 | 0 | fn encode_value(&self, writer: &mut impl Writer) -> Result<()> { |
77 | 0 | writer.write(self.as_ref()) |
78 | 0 | } |
79 | | } |
80 | | |
81 | | #[cfg(feature = "alloc")] |
82 | | mod allocating { |
83 | | use super::StrRef; |
84 | | use crate::{referenced::RefToOwned, StrOwned}; |
85 | | |
86 | | impl<'a> RefToOwned<'a> for StrRef<'a> { |
87 | | type Owned = StrOwned; |
88 | 0 | fn ref_to_owned(&self) -> Self::Owned { |
89 | 0 | StrOwned::from(*self) |
90 | 0 | } |
91 | | } |
92 | | } |