uselesskey-core-cache 0.7.1

Identity-keyed typed cache primitives for uselesskey fixture factories.
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

use std::sync::{Arc, Barrier};
use std::thread;

use uselesskey_core_cache::ArtifactCache;
use uselesskey_core_id::{ArtifactId, DerivationVersion};

fn make_id(domain: &'static str, label: &str, variant: &str) -> ArtifactId {
    ArtifactId::new(domain, label, b"spec", variant, DerivationVersion::V1)
}

#[test]
fn concurrent_reads_same_key() {
    let cache = Arc::new(ArtifactCache::new());
    let id = make_id("domain:test", "shared", "good");
    let original = cache.insert_if_absent_typed(id.clone(), Arc::new(42u64));

    let barrier = Arc::new(Barrier::new(10));
    let handles: Vec<_> = (0..10)
        .map(|_| {
            let cache = Arc::clone(&cache);
            let id = id.clone();
            let barrier = Arc::clone(&barrier);
            let original = Arc::clone(&original);
            thread::spawn(move || {
                barrier.wait();
                let val = cache.get_typed::<u64>(&id).expect("should find value");
                assert_eq!(*val, 42);
                assert!(Arc::ptr_eq(&val, &original));
            })
        })
        .collect();

    for h in handles {
        h.join().expect("thread panicked");
    }
}

#[test]
fn concurrent_writes_different_keys() {
    let cache = Arc::new(ArtifactCache::new());
    let barrier = Arc::new(Barrier::new(10));

    let handles: Vec<_> = (0..10)
        .map(|i| {
            let cache = Arc::clone(&cache);
            let barrier = Arc::clone(&barrier);
            thread::spawn(move || {
                barrier.wait();
                let id = make_id("domain:test", &format!("key-{i}"), "good");
                let val = cache.insert_if_absent_typed(id.clone(), Arc::new(i as u64));
                assert_eq!(*val, i as u64);
            })
        })
        .collect();

    for h in handles {
        h.join().expect("thread panicked");
    }
    assert_eq!(cache.len(), 10);
}

#[test]
fn cache_identity_same_tuple_same_arc() {
    let cache = ArtifactCache::new();
    let id = make_id("domain:rsa", "issuer", "good");

    let first = cache.insert_if_absent_typed(id.clone(), Arc::new(100u32));
    let second = cache.insert_if_absent_typed(id.clone(), Arc::new(200u32));
    let fetched = cache.get_typed::<u32>(&id).unwrap();

    assert!(Arc::ptr_eq(&first, &second));
    assert!(Arc::ptr_eq(&first, &fetched));
    assert_eq!(*first, 100);
}

#[test]
fn cache_isolation_different_keys_different_arcs() {
    let cache = ArtifactCache::new();
    let id_a = make_id("domain:rsa", "alice", "good");
    let id_b = make_id("domain:rsa", "bob", "good");

    let a = cache.insert_if_absent_typed(id_a, Arc::new(1u32));
    let b = cache.insert_if_absent_typed(id_b, Arc::new(2u32));

    assert!(!Arc::ptr_eq(&a, &b));
    assert_eq!(*a, 1);
    assert_eq!(*b, 2);
}

#[test]
fn high_contention_reads_and_writes() {
    let cache = Arc::new(ArtifactCache::new());

    // Pre-populate some keys
    for i in 0..5 {
        let id = make_id("domain:test", &format!("pre-{i}"), "good");
        cache.insert_if_absent_typed(id, Arc::new(i as u64));
    }

    let barrier = Arc::new(Barrier::new(20));
    let handles: Vec<_> = (0..20)
        .map(|i| {
            let cache = Arc::clone(&cache);
            let barrier = Arc::clone(&barrier);
            thread::spawn(move || {
                barrier.wait();
                if i % 2 == 0 {
                    // Reader: read pre-populated key
                    let key_idx = i / 2 % 5;
                    let id = make_id("domain:test", &format!("pre-{key_idx}"), "good");
                    let val = cache.get_typed::<u64>(&id).expect("pre-populated key");
                    assert_eq!(*val, key_idx as u64);
                } else {
                    // Writer: insert new key
                    let id = make_id("domain:test", &format!("new-{i}"), "good");
                    let val = cache.insert_if_absent_typed(id, Arc::new(i as u64));
                    assert_eq!(*val, i as u64);
                }
            })
        })
        .collect();

    for h in handles {
        h.join().expect("thread panicked");
    }

    // All pre-populated + new writer keys present
    assert!(cache.len() >= 5);
}

#[test]
fn cache_does_not_leak_across_domains() {
    let cache = ArtifactCache::new();
    let id_rsa = make_id("domain:rsa", "key", "good");
    let id_ecdsa = make_id("domain:ecdsa", "key", "good");

    cache.insert_if_absent_typed(id_rsa.clone(), Arc::new(1u32));

    assert!(cache.get_typed::<u32>(&id_rsa).is_some());
    assert!(cache.get_typed::<u32>(&id_ecdsa).is_none());
}

#[test]
fn cache_is_send_and_sync() {
    fn assert_send<T: Send>() {}
    fn assert_sync<T: Sync>() {}

    assert_send::<ArtifactCache>();
    assert_sync::<ArtifactCache>();
}