msy 0.4.2

Modern musl rsync alternative - Fast, parallel file synchronization
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

use clap::Parser;
use rayon::prelude::*;
use std::fs::{self, File};
use std::io::{BufWriter, Write};
use std::path::{Path, PathBuf};
use std::sync::atomic::{AtomicUsize, Ordering};
use std::time::Instant;

#[derive(Parser, Debug)]
#[command(name = "sy-bench-gen")]
#[command(about = "Generates massive file trees for sy benchmarking")]
struct Args {
    /// Root directory for the dataset
    #[arg(short, long, default_value = "bench_data")]
    root: PathBuf,

    /// Total number of files to generate
    #[arg(short, long, default_value_t = 100_000)]
    count: usize,

    /// Directory depth (creates nested structure)
    #[arg(short, long, default_value_t = 5)]
    depth: usize,

    /// Max files per directory
    #[arg(short, long, default_value_t = 100)]
    width: usize,

    /// Min file size in bytes
    #[arg(long, default_value_t = 100)]
    min_size: usize,

    /// Max file size in bytes
    #[arg(long, default_value_t = 10_000)]
    max_size: usize,

    /// Verification mode (verifies files exist instead of creating)
    #[arg(long)]
    verify: bool,
}

fn main() -> anyhow::Result<()> {
    let args = Args::parse();
    let start = Instant::now();

    if args.verify {
        println!("Verifying dataset at {:?}...", args.root);
        // Verification logic could go here
        return Ok(());
    }

    println!("Generating dataset at {:?}", args.root);
    println!("  Files: {}", args.count);
    println!("  Depth: {}", args.depth);
    println!("  Width: {}", args.width);
    println!("  Size:  {}-{} bytes", args.min_size, args.max_size);

    if args.root.exists() {
        println!("Cleaning up existing directory...");
        fs::remove_dir_all(&args.root)?;
    }
    fs::create_dir_all(&args.root)?;

    let files_created = AtomicUsize::new(0);
    let bytes_written = AtomicUsize::new(0);

    // Calculate directory structure
    // We want a tree that roughly balances files
    // For simplicity, we'll just map index -> path

    (0..args.count).into_par_iter().for_each(|i| {
        let path = generate_path(&args.root, i, args.depth, args.width);
        if let Some(parent) = path.parent() {
            let _ = fs::create_dir_all(parent);
        }

        let size = pseudo_random(i, args.min_size, args.max_size);
        let content = generate_content(i, size);

        if let Ok(file) = File::create(&path) {
            let mut writer = BufWriter::new(file);
            if writer.write_all(&content).is_ok() {
                files_created.fetch_add(1, Ordering::Relaxed);
                bytes_written.fetch_add(size, Ordering::Relaxed);
            }
        }
    });

    let duration = start.elapsed();
    let files = files_created.load(Ordering::Relaxed);
    let bytes = bytes_written.load(Ordering::Relaxed);

    println!("\nDone!");
    println!("  Time:    {:.2?}", duration);
    println!("  Files:   {}", files);
    println!("  Bytes:   {:.2} MB", bytes as f64 / 1_000_000.0);
    println!(
        "  Rate:    {:.2} files/sec",
        files as f64 / duration.as_secs_f64()
    );

    Ok(())
}

fn generate_path(root: &Path, index: usize, depth: usize, width: usize) -> PathBuf {
    let mut path = root.to_path_buf();
    let mut current = index;

    // Create deeper structure by modulo division
    for _ in 0..depth {
        let dir_idx = current % width;
        current /= width;
        path.push(format!("dir_{:03}", dir_idx));
        if current == 0 {
            break;
        }
    }

    path.push(format!("file_{:06}.dat", index));
    path
}

// Simple LCG for deterministic pseudo-random numbers
fn pseudo_random(seed: usize, min: usize, max: usize) -> usize {
    let mut x = seed as u64;
    x = x.wrapping_mul(6364136223846793005).wrapping_add(1);
    let r = (x >> 33) as usize; // Use upper bits
    min + (r % (max - min + 1))
}

fn generate_content(seed: usize, size: usize) -> Vec<u8> {
    let mut content = Vec::with_capacity(size);
    let mut x = seed as u64;

    // Fill with some pattern that isn't purely repeating (to test rolling hash/compression)
    for _ in 0..size {
        x = x.wrapping_mul(6364136223846793005).wrapping_add(1);
        content.push((x >> 33) as u8);
    }
    content
}