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dope_core/driver/
token.rs

1use core::marker::PhantomData;
2use core::num::NonZeroU64;
3
4use o3::collections::{CellSlab, Slab, SlabKey, SlabKeyParts};
5
6pub const ROUTE_FRAMEWORK: u8 = 255;
7
8pub const ROUTE_SHIFT: u32 = 56;
9pub const KIND_SHIFT: u32 = 48;
10const EPOCH_SHIFT: u32 = 24;
11const ROUTE_MASK: u64 = 0xFF << ROUTE_SHIFT;
12const KIND_MASK: u64 = 0xFF << KIND_SHIFT;
13pub const SLOT_BITS: u32 = 24;
14const EPOCH_BITS: u32 = 24;
15pub const SLOT_MASK: u64 = (1 << SLOT_BITS) - 1;
16pub const EPOCH_MASK: u64 = (1 << EPOCH_BITS) - 1;
17
18pub type Key<Tag> = SlabKey<Tag, { EPOCH_MASK as u32 }>;
19pub type TokenCellSlab<T, Tag> = CellSlab<T, Tag, { EPOCH_MASK as u32 }>;
20pub type TokenSlab<T, Tag> = Slab<T, Tag, { EPOCH_MASK as u32 }>;
21
22#[repr(transparent)]
23pub struct KeyParts<Tag> {
24    parts: SlabKeyParts<{ EPOCH_MASK as u32 }>,
25    tag: PhantomData<*mut Tag>,
26}
27
28impl<Tag> Clone for KeyParts<Tag> {
29    fn clone(&self) -> Self {
30        *self
31    }
32}
33
34impl<Tag> Copy for KeyParts<Tag> {}
35
36impl<Tag> KeyParts<Tag> {
37    pub const fn index(self) -> u32 {
38        self.parts.index()
39    }
40
41    pub const fn slab(self) -> SlabKeyParts<{ EPOCH_MASK as u32 }> {
42        self.parts
43    }
44}
45
46pub struct KeyTag<const ROUTE: u8, const KIND: u8 = 0>;
47
48pub trait TokenTag {
49    const ROUTE: u8;
50    const KIND: u8;
51    const MASK: u64;
52    const VALUE: u64;
53}
54
55impl<const ROUTE: u8, const KIND: u8> TokenTag for KeyTag<ROUTE, KIND> {
56    const ROUTE: u8 = ROUTE;
57    const KIND: u8 = KIND;
58    const MASK: u64 = ROUTE_MASK | if KIND == 0 { 0 } else { KIND_MASK };
59    const VALUE: u64 = (ROUTE as u64) << ROUTE_SHIFT | (KIND as u64) << KIND_SHIFT;
60}
61
62pub mod kind {
63    pub const ACCEPT: u8 = 1;
64    pub const RECV: u8 = 2;
65    pub const SEND: u8 = 3;
66    pub const TIMER: u8 = 4;
67    pub const SOCKET: u8 = 5;
68    pub const CONNECT: u8 = 6;
69    pub const SHUTDOWN: u8 = 7;
70    pub const SETSOCKOPT: u8 = 8;
71    pub const WRITE: u8 = 9;
72    pub const SYNC: u8 = 10;
73    pub const OPEN: u8 = 11;
74    pub const READ: u8 = 12;
75    pub const SPLICE: u8 = 13;
76    pub const RECV_DISCARD: u8 = 14;
77    pub const CREATE: u8 = 15;
78    pub const CLOSE_PREP: u8 = 16;
79    pub const CLOSE: u8 = 17;
80    pub const STAT: u8 = 18;
81    pub const ONE_SHOT: u8 = 19;
82    pub const READ_BLOCK: u8 = 20;
83    pub const TASK_QUEUE: u8 = 21;
84}
85
86#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash, Default)]
87#[repr(transparent)]
88pub struct SlotIndex(u32);
89
90impl SlotIndex {
91    pub const fn new(raw: u32) -> Self {
92        Self(raw)
93    }
94
95    pub const fn raw(self) -> u32 {
96        self.0
97    }
98}
99
100#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash, Default)]
101#[repr(transparent)]
102pub struct Epoch(u32);
103
104impl Epoch {
105    pub const INITIAL: Self = Self(1);
106    pub const MAX: Self = Self(EPOCH_MASK as u32);
107    pub const ZERO: Self = Self(0);
108
109    pub const fn new(raw: u32) -> Option<Self> {
110        if raw <= EPOCH_MASK as u32 {
111            Some(Self(raw))
112        } else {
113            None
114        }
115    }
116
117    pub const fn raw(self) -> u32 {
118        self.0
119    }
120
121    pub const fn next(self) -> Option<Self> {
122        if self.0 < EPOCH_MASK as u32 {
123            Some(Self(self.0 + 1))
124        } else {
125            None
126        }
127    }
128}
129
130#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
131#[repr(transparent)]
132pub struct Token(NonZeroU64, PhantomData<*mut ()>);
133
134impl Token {
135    pub const fn new(route: u8, slot: SlotIndex, epoch: Epoch) -> Self {
136        assert!((slot.0 as u64) <= SLOT_MASK, "dope: token slot overflow");
137        assert!((epoch.0 as u64) <= EPOCH_MASK, "dope: token epoch overflow");
138        let raw = ((route as u64) << ROUTE_SHIFT)
139            | ((epoch.0 as u64) << EPOCH_SHIFT)
140            | (slot.0 as u64 & SLOT_MASK);
141        Self::from_nonzero(raw)
142    }
143
144    pub const fn with_kind(self, kind: u8) -> Self {
145        let cleared = self.0.get() & !((0xFFu64) << KIND_SHIFT);
146        Self::from_nonzero(cleared | ((kind as u64) << KIND_SHIFT))
147    }
148
149    const fn from_nonzero(raw: u64) -> Self {
150        assert!(
151            raw != 0,
152            "dope: token requires a nonzero route, slot, or epoch"
153        );
154        Self(unsafe { NonZeroU64::new_unchecked(raw) }, PhantomData)
155    }
156
157    pub const fn try_from_raw(raw: u64) -> Option<Self> {
158        match NonZeroU64::new(raw) {
159            Some(v) => Some(Self(v, PhantomData)),
160            None => None,
161        }
162    }
163
164    pub const fn raw(self) -> u64 {
165        self.0.get()
166    }
167
168    pub const fn route(self) -> u8 {
169        (self.0.get() >> ROUTE_SHIFT) as u8
170    }
171
172    pub const fn kind(self) -> u8 {
173        ((self.0.get() & KIND_MASK) >> KIND_SHIFT) as u8
174    }
175
176    pub const fn slot(self) -> SlotIndex {
177        SlotIndex((self.0.get() & SLOT_MASK) as u32)
178    }
179
180    pub const fn epoch(self) -> Epoch {
181        Epoch(((self.0.get() >> EPOCH_SHIFT) & EPOCH_MASK) as u32)
182    }
183
184    pub const fn same_target(self, other: Self) -> bool {
185        self.0.get() & !KIND_MASK == other.0.get() & !KIND_MASK
186    }
187
188    #[allow(private_bounds)]
189    pub const fn parts<Tag: TokenTag>(self) -> Option<KeyParts<Tag>> {
190        if self.raw() & Tag::MASK != Tag::VALUE {
191            return None;
192        }
193        match SlabKeyParts::new(self.slot().raw(), self.epoch().raw()) {
194            Some(parts) => Some(KeyParts {
195                parts,
196                tag: PhantomData,
197            }),
198            None => None,
199        }
200    }
201
202    #[allow(private_bounds)]
203    pub const fn from_key<Tag: TokenTag>(key: Key<Tag>) -> Self {
204        Self::new(
205            Tag::ROUTE,
206            SlotIndex::new(key.index()),
207            Epoch(key.generation().get()),
208        )
209        .with_kind(Tag::KIND)
210    }
211}
212
213pub const SHUTDOWN: Token =
214    Token::new(ROUTE_FRAMEWORK, SlotIndex::new(0), Epoch::ZERO).with_kind(kind::SHUTDOWN);