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|
use std::convert::Infallible;
use std::path::PathBuf;
use criterion::measurement::Measurement;
use criterion::{
black_box, criterion_group, criterion_main, BenchmarkGroup, BenchmarkId, Criterion,
};
use git_repository::object::tree::diff::{Action, Change};
use git_repository::Id;
use imara_diff::intern::InternedInput;
use imara_diff::sink::Counter;
use imara_diff::Algorithm;
fn extract_diff(change: &Change) -> Option<(Vec<u8>, Vec<u8>)> {
use git_repository::object::tree::diff::change::Event::Modification;
let (previous_id, id) = match change.event {
Modification {
previous_entry_mode,
previous_id,
entry_mode,
id,
} if previous_entry_mode.is_blob() && entry_mode.is_blob() => (previous_id, id),
_ => return None,
};
let old = previous_id.object().ok()?.detach().data;
let new = id.object().ok()?.detach().data;
Some((new, old))
}
fn git_tree_diff(from: Id, to: Id, diffs: &mut Vec<(Vec<u8>, Vec<u8>, usize)>) {
let from_tree = from.object().unwrap().peel_to_tree().unwrap();
let to_tree = to.object().unwrap().peel_to_tree().unwrap();
from_tree
.changes()
.track_filename()
.for_each_to_obtain_tree(&to_tree, |change| -> Result<_, Infallible> {
if let Some((old, new)) = extract_diff(&change) {
let input = InternedInput::new(&*old, &*new);
let changes =
imara_diff::diff(Algorithm::Myers, &input, Counter::default()).total();
let complexity = changes * (old.len() + new.len());
diffs.push((old, new, complexity));
}
Ok(Action::Continue)
})
.unwrap();
}
pub fn project_root() -> PathBuf {
let dir = env!("CARGO_MANIFEST_DIR");
let mut res = PathBuf::from(dir);
while !res.join("README.md").exists() {
res = res
.parent()
.expect("reached fs root without finding project root")
.to_owned()
}
res
}
fn bench_repo(c: &mut Criterion, name: &str, tag2: &str, tag1: &str, num_commits: usize) {
let path = project_root().join("bench_data").join("repos").join(name);
let repo = git_repository::open(path).unwrap();
let tag1 = repo
.find_reference(tag1)
.unwrap()
.into_fully_peeled_id()
.unwrap();
let tag2 = repo
.find_reference(tag2)
.unwrap()
.into_fully_peeled_id()
.unwrap();
let mut diffs = Vec::new();
git_tree_diff(tag1, tag2, &mut diffs);
let mut last_commit = tag2;
tag2.object()
.unwrap()
.into_commit()
.ancestors()
.all()
.unwrap()
.take(num_commits as usize)
.for_each(|parent| {
let parent = parent.unwrap();
git_tree_diff(last_commit, parent, &mut diffs);
last_commit = parent;
});
diffs.sort_unstable_by_key(|(_, _, complexity)| *complexity);
if std::env::var("PLOT").is_ok() {
let mut group = c.benchmark_group(format!("{name}_plot"));
group.sample_size(15);
bench_file_diffs(group, &diffs, 12, true);
} else {
bench_file_diffs(c.benchmark_group(name), &diffs, 2, false);
}
}
fn bench_file_diffs<M: Measurement>(
mut group: BenchmarkGroup<M>,
files: &[(Vec<u8>, Vec<u8>, usize)],
num_chunks: usize,
compare_to_similar: bool,
) {
let mut run = |name, f: fn(&[u8], &[u8]) -> usize| {
let mut i = 0;
for chunk in files.chunks((files.len() + num_chunks - 1) / num_chunks) {
let mut average_complexity: usize = chunk.iter().map(|(_, _, it)| *it).sum();
average_complexity /= chunk.len();
println!("benchmarking {i}..{}/{}", i + chunk.len(), files.len());
i += chunk.len();
group.bench_function(
BenchmarkId::new(name, format!("{average_complexity}::{}", chunk.len())),
|b| {
b.iter(|| {
for (old, new, _) in chunk {
// myers algorithm is O(ND) where D is the length of the (minimal) edit script and N the sum of file lengths
// we use that as an x axis to find a meaningful way to plot a
black_box(f(old, new));
}
});
},
);
}
};
run("imara_diff-histogram", |file1, file2| {
let input = InternedInput::new(file1, file2);
imara_diff::diff(Algorithm::Histogram, &input, Counter::default()).total()
});
run("imara_diff-myers", |file1, file2| {
let input = InternedInput::new(file1, file2);
imara_diff::diff(Algorithm::Myers, &input, Counter::default()).total()
});
if compare_to_similar {
run("similar", |file1, file2| {
let diff = similar::utils::diff_lines(similar::Algorithm::Myers, file1, file2);
diff.len()
});
}
group.finish();
}
fn rust(c: &mut Criterion) {
bench_repo(c, "rust", "1.64.0", "1.50.0", 30);
}
fn vscode(c: &mut Criterion) {
bench_repo(c, "vscode", "1.72.2", "1.41.0", 30);
}
fn linux(c: &mut Criterion) {
bench_repo(c, "linux", "v6.0", "v5.7", 30);
}
fn helix(c: &mut Criterion) {
bench_repo(c, "helix", "22.08.1", "v0.5.0", 30);
}
criterion_group!(realworld_repos, helix, rust, vscode, linux);
criterion_main!(realworld_repos);
|
