ring/io/
positive.rs

1// Copyright 2018 Brian Smith.
2//
3// Permission to use, copy, modify, and/or distribute this software for any
4// purpose with or without fee is hereby granted, provided that the above
5// copyright notice and this permission notice appear in all copies.
6//
7// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
8// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
10// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
14
15//! Serialization and deserialization.
16
17/// A serialized positive integer.
18#[derive(Copy, Clone)]
19pub struct Positive<'a>(untrusted::Input<'a>);
20
21impl<'a> Positive<'a> {
22    #[inline]
23    pub(crate) fn new_non_empty_without_leading_zeros(input: untrusted::Input<'a>) -> Self {
24        debug_assert!(!input.is_empty());
25        debug_assert!(input.len() == 1 || input.as_slice_less_safe()[0] != 0);
26        Self(input)
27    }
28
29    /// Returns the value, ordered from significant byte to least significant
30    /// byte, without any leading zeros. The result is guaranteed to be
31    /// non-empty.
32    #[inline]
33    pub fn big_endian_without_leading_zero(&self) -> &'a [u8] {
34        self.big_endian_without_leading_zero_as_input()
35            .as_slice_less_safe()
36    }
37
38    #[inline]
39    pub(crate) fn big_endian_without_leading_zero_as_input(&self) -> untrusted::Input<'a> {
40        self.0
41    }
42}
43
44impl Positive<'_> {
45    /// Returns the first byte.
46    ///
47    /// Will not panic because the value is guaranteed to have at least one
48    /// byte.
49    pub fn first_byte(&self) -> u8 {
50        // This won't panic because
51        self.0.as_slice_less_safe()[0]
52    }
53}
ring/io/positive.rs

ring/io/
positive.rs
