wot_network/
trust_depth.rs

1use std::cmp::Ordering;
2
3/// The "trust depth" of a delegating certification.
4///
5/// See <https://www.rfc-editor.org/rfc/rfc9580.html#name-trust-signature>
6#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
7pub enum TrustDepth {
8    /// Encoded as 0 on the wire
9    None,
10    /// Can only be 1..=254
11    Limited(u8),
12    /// encoded as 255 on the wire
13    Unlimited,
14}
15
16impl From<u8> for TrustDepth {
17    fn from(value: u8) -> Self {
18        match value {
19            0 => Self::None,
20            u8::MAX => Self::Unlimited,
21            i => Self::Limited(i),
22        }
23    }
24}
25
26impl PartialEq<u8> for TrustDepth {
27    fn eq(&self, other: &u8) -> bool {
28        let other = TrustDepth::from(*other);
29        *self == other
30    }
31}
32
33impl PartialOrd<u8> for TrustDepth {
34    fn partial_cmp(&self, other: &u8) -> Option<Ordering> {
35        let other = TrustDepth::from(*other);
36        Some(self.cmp(&other))
37    }
38}
39
40impl PartialOrd<Self> for TrustDepth {
41    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
42        Some(self.cmp(other))
43    }
44}
45
46impl Ord for TrustDepth {
47    fn cmp(&self, other: &TrustDepth) -> Ordering {
48        match (*self, other) {
49            (Self::Unlimited, Self::Unlimited) => Ordering::Equal,
50            (Self::Unlimited, Self::Limited(_) | Self::None) => Ordering::Greater,
51            (Self::Limited(_) | Self::None, Self::Unlimited) => Ordering::Less,
52            (Self::None, Self::None) => Ordering::Equal,
53            (Self::None, Self::Limited(_)) => Ordering::Less,
54            (Self::Limited(_), Self::None) => Ordering::Greater,
55            (Self::Limited(value), Self::Limited(other)) => value.cmp(other),
56        }
57    }
58}
59
60impl From<TrustDepth> for u8 {
61    fn from(value: TrustDepth) -> Self {
62        match value {
63            TrustDepth::None => 0,
64            TrustDepth::Limited(i) => i,
65            TrustDepth::Unlimited => u8::MAX,
66        }
67    }
68}
69
70#[cfg(test)]
71mod tests {
72    use crate::TrustDepth;
73
74    #[test]
75    fn trust_depth() {
76        let depth1 = TrustDepth::Limited(0);
77        let depth2 = TrustDepth::Limited(1);
78        let depth3 = TrustDepth::Unlimited;
79
80        assert!(depth1 < depth2);
81        assert!(depth1 < depth3);
82        assert!(depth2 < depth3);
83
84        assert_eq!(depth1, depth1);
85        assert_eq!(depth2, depth2);
86        assert_eq!(depth3, depth3);
87    }
88}
wot_network/trust_depth.rs

wot_network/
trust_depth.rs
