1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
// Copyright 2018 Developers of the Rand project.
// Copyright 2013-2015 The Rust Project Developers.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use rand_core::Error;
use core::fmt;
/// Base code for all `JitterRng` errors
const ERROR_BASE: u32 = 0xAE53_0400;
/// An error that can occur when [`JitterRng::test_timer`] fails.
///
/// All variants have a value of 0xAE530400 = 2924676096 plus a small
/// increment (1 through 5).
///
/// [`JitterRng::test_timer`]: crate::JitterRng::test_timer
#[derive(Debug, Clone, PartialEq, Eq)]
#[repr(u32)]
pub enum TimerError {
/// No timer available.
NoTimer = ERROR_BASE + 1,
/// Timer too coarse to use as an entropy source.
CoarseTimer = ERROR_BASE + 2,
/// Timer is not monotonically increasing.
NotMonotonic = ERROR_BASE + 3,
/// Variations of deltas of time too small.
TinyVariantions = ERROR_BASE + 4,
/// Too many stuck results (indicating no added entropy).
TooManyStuck = ERROR_BASE + 5,
#[doc(hidden)]
__Nonexhaustive,
}
impl TimerError {
fn description(&self) -> &'static str {
match *self {
TimerError::NoTimer => "no timer available",
TimerError::CoarseTimer => "coarse timer",
TimerError::NotMonotonic => "timer not monotonic",
TimerError::TinyVariantions => "time delta variations too small",
TimerError::TooManyStuck => "too many stuck results",
TimerError::__Nonexhaustive => unreachable!(),
}
}
}
impl fmt::Display for TimerError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.description())
}
}
#[cfg(feature = "std")]
impl ::std::error::Error for TimerError {
fn description(&self) -> &str {
self.description()
}
}
impl From<TimerError> for Error {
fn from(err: TimerError) -> Error {
// Timer check is already quite permissive of failures so we don't
// expect false-positive failures, i.e. any error is irrecoverable.
#[cfg(feature = "std")] {
Error::new(err)
}
#[cfg(not(feature = "std"))] {
Error::from(core::num::NonZeroU32::new(err as u32).unwrap())
}
}
}
|
