arcache 0.0.2

Thread safe cache implementations with a shared trait to make caches interchangeable.
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

use arcache::{Cache, LRUCache};
use rand::rng;
use rand::{seq::SliceRandom, Rng};
use std::sync::Arc;
use std::thread;
use std::time::{Duration, Instant};

#[derive(Debug, Clone)]
struct UserData {
    _id: String,
    _name: String,
    _email: String,
}

/// Simulates fetching user data from a database.
fn fetch_user_data(user_id: &str) -> UserData {
    thread::sleep(Duration::from_millis(300)); // Simulate network delay
    UserData {
        _id: user_id.to_string(),
        _name: format!("User {}", user_id),
        _email: format!("user{}@example.com", user_id),
    }
}

/// Retrieves user data using a shared TTL cache.
fn get_user_data(user_id: &str, cache: &LRUCache<String, UserData>) -> UserData {
    if let Some(cached) = cache.get(&user_id.to_string()) {
        return cached.as_ref().clone();
    }
    let user_data = fetch_user_data(user_id);
    cache.set(user_id.to_string(), user_data.clone());
    user_data
}

fn main() {
    let mut user_ids: Vec<String> = vec![];
    let num_users = 20;
    let repetitions = 4;
    let num_threads = 10;
    let cache_capacity = 20;

    for _ in 0..repetitions {
        for i in 0..num_users {
            user_ids.push(format!("{}", i));
        }
    }

    let mut random = rng();
    user_ids.shuffle(&mut random);

    // --- Single-threaded execution using LRUCache ---
    let ttl_cache = LRUCache::<String, UserData>::new(cache_capacity);
    let start = Instant::now();
    for user_id in &user_ids {
        let data = get_user_data(user_id, &ttl_cache);
        println!("Single-threaded result: {:?}", data);
    }
    let single_duration = start.elapsed();
    println!("Single-threaded execution time: {:?}", single_duration);

    // --- Multithreaded execution ---
    let arc_cache = Arc::new(LRUCache::<String, UserData>::new(cache_capacity));
    let start = Instant::now();
    let mut handles = Vec::new();

    let chunk_size = user_ids.len().div_ceil(num_threads);
    for chunk in user_ids.chunks(chunk_size) {
        let cache_clone = Arc::clone(&arc_cache);
        let chunk: Vec<String> = chunk.to_vec();
        let handle = thread::spawn(move || {
            let mut local_rng = rng();
            for user_id in &chunk {
                let delay = local_rng.random_range(0..=3);
                thread::sleep(Duration::from_millis(delay));
                let data = get_user_data(user_id, &cache_clone);
                println!("Multithreaded result: {:?}", data);
            }
        });
        handles.push(handle);
    }

    for handle in handles {
        handle.join().unwrap();
    }

    let multi_duration = start.elapsed();
    println!("Multithreaded execution time: {:?}", multi_duration);

    let speedup = single_duration.as_secs_f64() / multi_duration.as_secs_f64();
    println!("Multithreading speedup: {:.2}x", speedup);

    // Optionally, if your LRUCache has stats:
    println!("Cache stats: {:?}", arc_cache.stats());
}