moka 0.3.0

A fast and concurrent cache library inspired by Caffeine (Java) and Ristretto (Go)
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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176

//! Provides a *not* thread-safe, blocking cache implementation.

pub(crate) mod builder;
pub(crate) mod cache;
mod deques;

use std::{ptr::NonNull, rc::Rc};

pub use builder::CacheBuilder;
pub use cache::Cache;
use quanta::Instant;

use crate::common::{deque::DeqNode, AccessTime};

pub(crate) struct KeyDate<K> {
    pub(crate) key: Rc<K>,
    pub(crate) timestamp: Option<Instant>,
}

impl<K> KeyDate<K> {
    pub(crate) fn new(key: Rc<K>, timestamp: Option<Instant>) -> Self {
        Self { key, timestamp }
    }
}

pub(crate) struct KeyHashDate<K> {
    pub(crate) key: Rc<K>,
    pub(crate) hash: u64,
    pub(crate) timestamp: Option<Instant>,
}

impl<K> KeyHashDate<K> {
    pub(crate) fn new(key: Rc<K>, hash: u64, timestamp: Option<Instant>) -> Self {
        Self {
            key,
            hash,
            timestamp,
        }
    }
}

// DeqNode for an access order queue.
type KeyDeqNodeAo<K> = NonNull<DeqNode<KeyHashDate<K>>>;

// DeqNode for the write order queue.
type KeyDeqNodeWo<K> = NonNull<DeqNode<KeyDate<K>>>;

struct DeqNodes<K> {
    access_order_q_node: Option<KeyDeqNodeAo<K>>,
    write_order_q_node: Option<KeyDeqNodeWo<K>>,
}

pub(crate) struct ValueEntry<K, V> {
    pub(crate) value: V,
    deq_nodes: DeqNodes<K>,
}

impl<K, V> ValueEntry<K, V> {
    pub(crate) fn new(value: V) -> Self {
        Self {
            value,
            deq_nodes: DeqNodes {
                access_order_q_node: None,
                write_order_q_node: None,
            },
        }
    }

    #[inline]
    pub(crate) fn replace_deq_nodes_with(&mut self, mut other: Self) {
        self.deq_nodes.access_order_q_node = other.deq_nodes.access_order_q_node.take();
        self.deq_nodes.write_order_q_node = other.deq_nodes.write_order_q_node.take();
    }

    #[inline]
    pub(crate) fn access_order_q_node(&self) -> Option<KeyDeqNodeAo<K>> {
        self.deq_nodes.access_order_q_node
    }

    #[inline]
    pub(crate) fn set_access_order_q_node(&mut self, node: Option<KeyDeqNodeAo<K>>) {
        self.deq_nodes.access_order_q_node = node;
    }

    #[inline]
    pub(crate) fn take_access_order_q_node(&mut self) -> Option<KeyDeqNodeAo<K>> {
        self.deq_nodes.access_order_q_node.take()
    }

    #[inline]
    pub(crate) fn write_order_q_node(&self) -> Option<KeyDeqNodeWo<K>> {
        self.deq_nodes.write_order_q_node
    }

    #[inline]
    pub(crate) fn set_write_order_q_node(&mut self, node: Option<KeyDeqNodeWo<K>>) {
        self.deq_nodes.write_order_q_node = node;
    }

    #[inline]
    pub(crate) fn take_write_order_q_node(&mut self) -> Option<KeyDeqNodeWo<K>> {
        self.deq_nodes.write_order_q_node.take()
    }
}

impl<K, V> AccessTime for ValueEntry<K, V> {
    #[inline]
    fn last_accessed(&self) -> Option<Instant> {
        self.access_order_q_node()
            .and_then(|node| unsafe { node.as_ref() }.element.timestamp)
    }

    #[inline]
    fn set_last_accessed(&mut self, timestamp: Instant) {
        if let Some(mut node) = self.deq_nodes.access_order_q_node {
            unsafe { node.as_mut() }.set_last_accessed(timestamp);
        }
    }

    #[inline]
    fn last_modified(&self) -> Option<Instant> {
        self.write_order_q_node()
            .and_then(|node| unsafe { node.as_ref() }.element.timestamp)
    }

    #[inline]
    fn set_last_modified(&mut self, timestamp: Instant) {
        if let Some(mut node) = self.deq_nodes.write_order_q_node {
            unsafe { node.as_mut() }.set_last_modified(timestamp);
        }
    }
}

impl<K> AccessTime for DeqNode<KeyDate<K>> {
    #[inline]
    fn last_accessed(&self) -> Option<Instant> {
        None
    }

    #[inline]
    fn set_last_accessed(&mut self, _timestamp: Instant) {
        unreachable!();
    }

    #[inline]
    fn last_modified(&self) -> Option<Instant> {
        self.element.timestamp
    }

    #[inline]
    fn set_last_modified(&mut self, timestamp: Instant) {
        self.element.timestamp = Some(timestamp);
    }
}

impl<K> AccessTime for DeqNode<KeyHashDate<K>> {
    #[inline]
    fn last_accessed(&self) -> Option<Instant> {
        self.element.timestamp
    }

    #[inline]
    fn set_last_accessed(&mut self, timestamp: Instant) {
        self.element.timestamp = Some(timestamp);
    }

    #[inline]
    fn last_modified(&self) -> Option<Instant> {
        None
    }

    #[inline]
    fn set_last_modified(&mut self, _timestamp: Instant) {
        unreachable!();
    }
}