commonware-consensus 2026.10.0

Order opaque messages in a Byzantine environment.
Documentation 
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
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134

//! Reporter implementations for various standard types.

use crate::Reporter;
use commonware_actor::Feedback;

/// An implementation of [Reporter] for an optional [Reporter].
///
/// This is useful for reporting activity to a [Reporter] that may not be present.
/// Reporting is ignored if the [Reporter] is `None`.
impl<R: Reporter> Reporter for Option<R> {
    type Activity = R::Activity;

    fn report(&mut self, activity: Self::Activity) -> Feedback {
        let Some(reporter) = self else {
            return Feedback::Ok;
        };
        reporter.report(activity)
    }
}

/// A struct used to report activity to multiple [Reporter]s (which may or may not be present).
#[derive(Clone)]
pub struct Reporters<R1, R2> {
    r1: Option<R1>,
    r2: Option<R2>,
}

impl<R1, R2> Reporter for Reporters<R1, R2>
where
    R1: Reporter,
    R2: Reporter<Activity = R1::Activity>,
    R1::Activity: Clone,
{
    type Activity = R1::Activity;

    fn report(&mut self, activity: Self::Activity) -> Feedback {
        // This approach avoids cloning activity, if possible.
        match (&mut self.r1, &mut self.r2) {
            (Some(r1), Some(r2)) => combine(r1.report(activity.clone()), r2.report(activity)),
            (Some(r1), None) => r1.report(activity),
            (None, Some(r2)) => r2.report(activity),
            (None, None) => Feedback::Ok,
        }
    }
}

const fn combine(a: Feedback, b: Feedback) -> Feedback {
    match (a, b) {
        (Feedback::Closed, _) | (_, Feedback::Closed) => Feedback::Closed,
        (Feedback::Backoff, _) | (_, Feedback::Backoff) => Feedback::Backoff,
        (Feedback::Ok, Feedback::Ok) => Feedback::Ok,
    }
}

impl<R1, R2> From<(Option<R1>, Option<R2>)> for Reporters<R1, R2> {
    fn from((r1, r2): (Option<R1>, Option<R2>)) -> Self {
        Self { r1, r2 }
    }
}

impl<R1, R2> From<(Option<R1>, R2)> for Reporters<R1, R2> {
    fn from((r1, r2): (Option<R1>, R2)) -> Self {
        Self { r1, r2: Some(r2) }
    }
}

impl<R1, R2> From<(R1, Option<R2>)> for Reporters<R1, R2> {
    fn from((r1, r2): (R1, Option<R2>)) -> Self {
        Self { r1: Some(r1), r2 }
    }
}

impl<R1, R2> From<(R1, R2)> for Reporters<R1, R2> {
    fn from((r1, r2): (R1, R2)) -> Self {
        Self {
            r1: Some(r1),
            r2: Some(r2),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use commonware_actor::Feedback;
    use commonware_utils::acknowledgement::{Acknowledgement, Exact};
    use futures::FutureExt;

    #[derive(Clone, Debug)]
    struct SimpleAcknowledger;

    impl crate::Reporter for SimpleAcknowledger {
        type Activity = Exact;

        fn report(&mut self, activity: Self::Activity) -> Feedback {
            activity.acknowledge();
            Feedback::Ok
        }
    }

    #[test]
    fn optional_branch_acknowledges() {
        let mut reporters = Reporters::<SimpleAcknowledger, SimpleAcknowledger>::from((
            Some(SimpleAcknowledger),
            None,
        ));

        let (ack, waiter) = Exact::handle();
        assert_eq!(reporters.report(ack), Feedback::Ok);

        assert!(
            waiter.now_or_never().unwrap().is_ok(),
            "Waiter did not resolve successfully"
        );
    }

    #[test]
    fn absent_reporter_ignores_activity() {
        let mut reporter = Option::<SimpleAcknowledger>::None;
        let (ack, waiter) = Exact::handle();
        assert_eq!(reporter.report(ack), Feedback::Ok);
        assert!(waiter.now_or_never().unwrap().is_err());
    }

    #[test]
    fn combine_returns_worst_feedback() {
        assert_eq!(
            combine(Feedback::Closed, Feedback::Backoff),
            Feedback::Closed
        );
        assert_eq!(combine(Feedback::Backoff, Feedback::Ok), Feedback::Backoff);
        assert_eq!(combine(Feedback::Ok, Feedback::Ok), Feedback::Ok);
    }
}