paxakos 0.1.0

Rust implementation of Paxos consensus algorithm
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

use thiserror::Error;

use crate::append::AppendError;
use crate::error::{AcceptError, AffirmSnapshotError, CommitError, InstallSnapshotError};
use crate::error::{PrepareError, PrepareSnapshotError, ReadStaleError};
use crate::state::State;
use crate::{CoordNum, RoundNum};

#[derive(Debug)]
pub struct ShutDown;

impl ShutDown {
    pub(super) fn as_unit<T>(self) -> () {}

    pub(super) fn rule_out<T>(result: Result<T, ShutDown>) -> T {
        result.unwrap()
    }
}

impl From<ShutDown> for AppendError {
    fn from(_: ShutDown) -> Self {
        AppendError::ShutDown
    }
}

impl From<ShutDown> for ReadStaleError {
    fn from(_: ShutDown) -> Self {
        Self::ShutDown
    }
}

impl<S: State, C: CoordNum> From<ShutDown> for PrepareError<S, C> {
    fn from(_: ShutDown) -> Self {
        Self::ShutDown
    }
}

impl<S: State, C: CoordNum> From<ShutDown> for AcceptError<S, C> {
    fn from(_: ShutDown) -> Self {
        Self::ShutDown
    }
}

impl<S: State> From<ShutDown> for CommitError<S> {
    fn from(_: ShutDown) -> Self {
        Self::ShutDown
    }
}

impl From<ShutDown> for AcquireRoundNumError {
    fn from(_: ShutDown) -> Self {
        Self::ShutDown
    }
}

impl<R: RoundNum> From<ShutDown> for ClusterError<R> {
    fn from(_: ShutDown) -> Self {
        Self::ShutDown
    }
}

impl From<ShutDown> for PrepareSnapshotError {
    fn from(_: ShutDown) -> Self {
        Self::ShutDown
    }
}

impl From<ShutDown> for AffirmSnapshotError {
    fn from(_: ShutDown) -> Self {
        Self::ShutDown
    }
}

impl From<ShutDown> for InstallSnapshotError {
    fn from(_: ShutDown) -> Self {
        Self::ShutDown
    }
}

#[derive(Debug, Error)]
pub enum AcquireRoundNumError {
    #[error("the round has already converged")]
    Converged,

    #[error("node is disoriented")]
    Disoriented,

    #[error("node is shut down")]
    ShutDown,
}

impl From<AcquireRoundNumError> for AppendError {
    fn from(e: AcquireRoundNumError) -> Self {
        match e {
            AcquireRoundNumError::Converged => AppendError::Converged,
            AcquireRoundNumError::Disoriented => AppendError::Disoriented,
            AcquireRoundNumError::ShutDown => AppendError::ShutDown,
        }
    }
}

#[derive(Debug, Error)]
pub enum ClusterError<R: RoundNum> {
    #[error("the round has already converged")]
    Converged(R),

    #[error("node is disoriented")]
    Disoriented,

    #[error("node is shut down")]
    ShutDown,
}

impl<R: RoundNum> From<ClusterError<R>> for AppendError {
    fn from(e: ClusterError<R>) -> Self {
        match e {
            ClusterError::Disoriented => AppendError::Disoriented,
            ClusterError::Converged(_) => AppendError::Converged,
            ClusterError::ShutDown => AppendError::ShutDown,
        }
    }
}