feat(benchmarks): add benchmark for the file loader

Cargo.toml

@@ -1,3 +1,3 @@
 [workspace]
-members = ["swiftide", "examples"]
+members = ["swiftide", "examples", "benchmarks"]
 resolver = "2"

benchmarks/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "benchmarks"
+version = "0.0.0"
+publish = false
+edition = "2021"
+
+[dev-dependencies]
+tokio = { version = "1.0", features = ["full"] }
+swiftide = { path = "../swiftide/", features = ["all"] }
+tracing-subscriber = "0.3"
+serde_json = "1.0"
+criterion = { version = "0.5.1", features = ["html_reports"] }
+anyhow = "1.0"
+futures-util = "0.3"
+
+[[bench]]
+name = "fileloader"
+path = "fileloader.rs"
+harness = false

benchmarks/fileloader.rs

@@ -0,0 +1,26 @@
+use anyhow::Result;
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use futures_util::stream::TryStreamExt;
+use swiftide::{ingestion::StreamExt, traits::Loader};
+
+async fn run_fileloader(num_files: usize) -> Result<usize> {
+    let mut total_nodes = 0;
+    let mut stream = swiftide::loaders::FileLoader::new(".")
+        .with_extensions(&["rs"])
+        .into_stream()
+        .take(num_files);
+
+    while stream.try_next().await?.is_some() {
+        total_nodes += 1;
+    }
+    assert!(total_nodes == num_files);
+    Ok(total_nodes)
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    c.bench_function("load_1", |b| b.iter(|| run_fileloader(black_box(1))));
+    c.bench_function("load_10", |b| b.iter(|| run_fileloader(black_box(10))));
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);