Benchmarking with criterion

Cargo.toml

@@ -24,6 +24,13 @@ serde_derive = "1"
 serde_json = "1"
 tokio = { version = "1.23.0", features = ["full"] }
 
+[dev-dependencies]
+criterion = { version = "0.5.1", features = ["html_reports"] }
+
+[[bench]]
+name = "my_benchmark"
+harness = false
+
 [workspace]
 members = [
   "src/adder",

benches/my_benchmark.rs

@@ -0,0 +1,16 @@
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+
+fn fibonacci(n: u64) -> u64 {
+    match n {
+        0 => 1,
+        1 => 1,
+        n => fibonacci(n-1) + fibonacci(n-2),
+    }
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    c.bench_function("fib 20", |b| b.iter(|| fibonacci(black_box(20))));
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);