fncache 0.1.2

A zero-boilerplate Rust library for function-level caching with pluggable backends
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

// Only run these integration tests when the test-utils feature is enabled
// This is necessary because we need to reset the global cache between tests
#![cfg(feature = "test-utils")]

use fncache::{backends::memory::MemoryBackend, init_global_cache, FncacheError, Result};

// Only import reset_global_cache_for_testing when the test-utils feature is enabled
#[cfg(feature = "test-utils")]
use fncache::reset_global_cache_for_testing;
use serial_test::serial;
use std::time::Duration;
use tokio::time::sleep;

use bincode;
use futures::TryFutureExt;
use serde::{Deserialize, Serialize};

fn system_time_error_to_fncache_error(err: std::time::SystemTimeError) -> FncacheError {
    FncacheError::Backend(err.to_string())
}

fn setup_test_cache() -> Result<()> {
    #[cfg(feature = "test-utils")]
    reset_global_cache_for_testing();
    init_global_cache(MemoryBackend::new())
}

#[test]
#[serial]
fn test_sync_caching() -> Result<()> {
    setup_test_cache()?;

    #[fncache::fncache(ttl = 5)]
    fn add(a: i32, b: i32) -> i32 {
        a + b
    }

    let result1 = add(2, 3);
    assert_eq!(result1, 5);

    let result2 = add(2, 3);
    assert_eq!(result2, 5);

    let result3 = add(3, 4);
    assert_eq!(result3, 7);

    Ok(())
}

#[tokio::test]
#[serial]
async fn test_async_caching() -> Result<()> {
    setup_test_cache()?;

    #[fncache::fncache(ttl = 5)]
    async fn multiply(a: i32, b: i32) -> i32 {
        sleep(Duration::from_millis(100)).await;
        a * b
    }

    let result1 = multiply(2, 3).await;
    assert_eq!(result1, 6);

    let result2 = multiply(2, 3).await;
    assert_eq!(result2, 6);

    let result3 = multiply(3, 4).await;
    assert_eq!(result3, 12);

    Ok(())
}

#[tokio::test]
#[serial]
async fn test_ttl_expiration() -> Result<()> {
    setup_test_cache()?;

    #[fncache::fncache(ttl = 1)]
    async fn get_timestamp() -> u128 {
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_millis()
    }

    let timestamp1 = get_timestamp().await;
    let timestamp2 = get_timestamp().await;
    assert_eq!(timestamp1, timestamp2);

    sleep(Duration::from_secs(2)).await;

    let timestamp3 = get_timestamp().await;
    assert_ne!(timestamp1, timestamp3);

    Ok(())
}

#[test]
#[serial]
fn test_error_handling() -> Result<()> {
    setup_test_cache()?;

    #[fncache::fncache(ttl = 5)]
    fn might_fail(succeed: bool) -> Option<String> {
        if succeed {
            Some("success".to_string())
        } else {
            None
        }
    }

    let result = might_fail(true);
    assert_eq!(result, Some("success".to_string()));

    assert_eq!(might_fail(false), None);

    Ok(())
}

#[test]
#[serial]
fn test_different_argument_types() -> Result<()> {
    setup_test_cache()?;

    #[fncache::fncache(ttl = 5)]
    fn process_data(s: &str, nums: Vec<i32>) -> String {
        let sum: i32 = nums.iter().sum();
        format!("{}: {}", s, sum)
    }

    let result1 = process_data("test", vec![1, 2, 3]);
    assert_eq!(result1, "test: 6");

    let result2 = process_data("test", vec![1, 2, 3]);
    assert_eq!(result2, "test: 6");

    let result3 = process_data("sum", vec![4, 5, 6]);
    assert_eq!(result3, "sum: 15");

    Ok(())
}