sark-core 0.29.3

Fiber-free request, route, dispatch, and lifecycle core for Sark
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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154

//! Affine carrier admission proofs for one duplex turn.
use core::marker;

use o3::{
    base::marker::ThreadBound,
    buffer::{resident, segments},
};

use crate::duplex::machine;

type Owner<'turn, D> = marker::PhantomData<(
    D,
    ThreadBound,
    fn(D) -> D,
    fn(&'turn mut ()) -> &'turn mut (),
)>;

/// Session output and terminal state bound to one machine turn.
#[must_use = "classify this emitted duplex turn"]
pub struct Emission<'turn, 'd, D> {
    pub(in crate::duplex) payload: Payload<'turn, 'd, D>,
    pub(in crate::duplex) end: machine::End,
    pub(in crate::duplex) after: machine::After,
}

impl<'turn, 'd, D> Emission<'turn, 'd, D> {
    pub fn into_parts(self) -> (Payload<'turn, 'd, D>, machine::End, machine::After) {
        (self.payload, self.end, self.after)
    }
}

/// Exact ownership state of the session output for this turn.
#[must_use = "consume the payload and its admission permission"]
pub enum Payload<'turn, 'd, D> {
    Present {
        output: segments::Nonempty<resident::Shared<'d>>,
        permit: Permit<'turn, Present, D>,
    },
    Vacant(Permit<'turn, Vacant, D>),
}

/// Proof that this turn owns an output chunk.
pub enum Present {}

/// Proof that this turn has no output chunk.
pub enum Vacant {}

/// Affine permission to classify one carrier admission attempt.
#[must_use = "classify this carrier admission attempt"]
pub struct Permit<'turn, M, D> {
    pub(in crate::duplex) owner: Owner<'turn, D>,
    pub(in crate::duplex) mode: marker::PhantomData<M>,
}

impl<'turn, M, D> Permit<'turn, M, D> {
    pub fn commit<'d, R, E>(self, receipt: R) -> Admission<'turn, 'd, D, R, E> {
        Admission::new(self.owner, Decision::Committed { receipt })
    }
}

impl<'turn, D> Permit<'turn, Present, D> {
    pub fn pending<'d, R, E>(
        self,
        rest: segments::Nonempty<resident::Shared<'d>>,
        receipt: R,
    ) -> Admission<'turn, 'd, D, R, E> {
        Admission::new(
            self.owner,
            Decision::Pending {
                remainder: rest,
                receipt,
            },
        )
    }

    pub fn returned<'d, R, E>(
        self,
        error: E,
        rest: segments::Nonempty<resident::Shared<'d>>,
    ) -> Admission<'turn, 'd, D, R, E> {
        Admission::new(
            self.owner,
            Decision::Returned {
                error,
                remainder: rest,
            },
        )
    }
}

impl<'turn, D> Permit<'turn, Vacant, D> {
    pub fn blocked<'d, R, E>(self, receipt: R) -> Admission<'turn, 'd, D, R, E> {
        Admission::new(self.owner, Decision::Blocked { receipt })
    }

    pub fn reject<'d, R, E>(self, error: E) -> Admission<'turn, 'd, D, R, E> {
        Admission::new(self.owner, Decision::Rejected { error })
    }
}

/// Exact carrier disposition joined to its originating machine turn.
#[must_use = "return this disposition to the duplex machine"]
#[repr(transparent)]
pub struct Admission<'turn, 'd, D, R, E> {
    pub(in crate::duplex) decision: Decision<'d, R, E>,
    pub(in crate::duplex) owner: Owner<'turn, D>,
}

impl<'turn, 'd, D, R, E> Admission<'turn, 'd, D, R, E> {
    fn new(owner: Owner<'turn, D>, decision: Decision<'d, R, E>) -> Self {
        Self { decision, owner }
    }
}

pub(in crate::duplex) enum Decision<'d, R, E> {
    Committed {
        receipt: R,
    },
    Pending {
        remainder: segments::Nonempty<resident::Shared<'d>>,
        receipt: R,
    },
    Blocked {
        receipt: R,
    },
    Rejected {
        error: E,
    },
    Returned {
        error: E,
        remainder: segments::Nonempty<resident::Shared<'d>>,
    },
}

const _: () = {
    assert!(core::mem::size_of::<Permit<'static, Present, crate::duplex::Never>>() == 0);
    assert!(core::mem::align_of::<Permit<'static, Present, crate::duplex::Never>>() == 1);
    assert!(
        core::mem::size_of::<Payload<'static, 'static, crate::duplex::Never>>()
            == core::mem::size_of::<Option<segments::Nonempty<resident::Shared<'static>>>>()
    );
    assert!(
        core::mem::align_of::<Payload<'static, 'static, crate::duplex::Never>>()
            == core::mem::align_of::<Option<segments::Nonempty<resident::Shared<'static>>>>()
    );
    assert!(
        core::mem::size_of::<Admission<'static, 'static, crate::duplex::Never, usize, usize>>()
            == core::mem::size_of::<Decision<'static, usize, usize>>()
    );
    assert!(
        core::mem::align_of::<Admission<'static, 'static, crate::duplex::Never, usize, usize>>()
            == core::mem::align_of::<Decision<'static, usize, usize>>()
    );
};