weavatrix-git 0.3.1

Fast, bounded, evidence-carrying Git reader with an optional read-only MCP server
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

use std::{
    env,
    path::Path,
    process::Command,
    time::{Duration, Instant},
};

use weavatrix_git::{HistoryOptions, Repository};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let args = env::args().skip(1).collect::<Vec<_>>();
    let path = args.first().map_or(".", String::as_str);
    let max_count = parse(&args, 1, 500)?;
    let iterations = parse(&args, 2, 20)?;
    let expected = git_ids(path, max_count)?;
    let repository = Repository::open(path)?;
    let start = repository.resolve("HEAD")?;
    let options = HistoryOptions {
        max_commits: max_count,
        first_parent: true,
        ..HistoryOptions::default()
    };
    let actual = repository
        .history_ids(start, options)?
        .into_iter()
        .map(|id| id.to_string())
        .collect::<Vec<_>>();
    if actual != expected {
        return Err("history identifiers differ from git rev-list".into());
    }

    let warm = measure(iterations, || {
        repository
            .history_ids(start, options)
            .map(|identifiers| identifiers.len())
    })?;
    let reopen = measure(iterations, || {
        let repo = Repository::open(path)?;
        repo.history_ids(repo.resolve("HEAD")?, options)
            .map(|identifiers| identifiers.len())
    })?;
    let git = measure(iterations, || git_ids(path, max_count).map(|ids| ids.len()))?;
    println!("engine,mode,p50_ms,p95_ms,commits");
    print_row("weavatrix-git", "warm", &warm, actual.len());
    print_row("weavatrix-git", "reopen", &reopen, actual.len());
    print_row("git.exe", "process", &git, expected.len());
    Ok(())
}

fn parse(
    args: &[String],
    index: usize,
    fallback: usize,
) -> Result<usize, Box<dyn std::error::Error>> {
    Ok(args
        .get(index)
        .map(|value| value.parse())
        .transpose()?
        .unwrap_or(fallback))
}

fn git_ids(path: impl AsRef<Path>, max: usize) -> Result<Vec<String>, Box<dyn std::error::Error>> {
    let output = Command::new("git")
        .arg("-C")
        .arg(path.as_ref())
        .args(["rev-list", "--first-parent", "--max-count"])
        .arg(max.to_string())
        .arg("HEAD")
        .output()?;
    if !output.status.success() {
        return Err(String::from_utf8_lossy(&output.stderr).into_owned().into());
    }
    Ok(String::from_utf8(output.stdout)?
        .lines()
        .map(str::to_owned)
        .collect())
}

fn measure<T, E>(
    iterations: usize,
    mut operation: impl FnMut() -> Result<T, E>,
) -> Result<Vec<Duration>, E> {
    for _ in 0..3 {
        let _ = operation()?;
    }
    let mut values = Vec::with_capacity(iterations);
    for _ in 0..iterations {
        let start = Instant::now();
        let _ = operation()?;
        values.push(start.elapsed());
    }
    values.sort_unstable();
    Ok(values)
}

fn print_row(engine: &str, mode: &str, values: &[Duration], commits: usize) {
    let p50 = values[values.len() / 2].as_secs_f64() * 1_000.0;
    let p95 = values[(values.len() * 95 / 100).min(values.len() - 1)].as_secs_f64() * 1_000.0;
    println!("{engine},{mode},{p50:.3},{p95:.3},{commits}");
}