<div align="center">
<h1>codspeed-criterion-compat</h1>
[](https://github.com/CodSpeedHQ/codspeed-rust/actions/workflows/ci.yml)
[](https://crates.io/crates/codspeed-criterion-compat)
[](https://discord.com/invite/MxpaCfKSqF)
[](https://codspeed.io/CodSpeedHQ/codspeed-rust)
Criterion.rs compatibility layer for CodSpeed
</div>
## Installation
```sh
cargo add --dev codspeed-criterion-compat --rename criterion
```
> [!NOTE]
> This will install the `codspeed-criterion-compat` crate and rename it to `criterion` in your `Cargo.toml`.
> This way, you can keep your existing imports and the compatibility layer will take care of the rest.
>
> Using the compatibility layer won't change the behavior of your benchmark suite and Criterion.rs will still run it as usual.
>
> If you prefer, you can also install `codspeed-criterion-compat` as is and change your imports to use this new crate name.
## Usage
Let's start with the example from the [Criterion.rs documentation](https://bheisler.github.io/criterion.rs/book/getting_started.html),
creating a benchmark suite for the Fibonacci function (in `benches/my_benchmark.rs`):
```rust
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),
}
}
pub 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);
```
The last step in creating the Criterion benchmark is to add the new benchmark target in your `Cargo.toml`:
```toml title="Cargo.toml"
[[bench]]
name = "my_benchmark"
harness = false
```
And that's it! You can now run your benchmark suite with `cargo-codspeed`:
```
$ cargo codspeed build
Finished release [optimized] target(s) in 0.12s
Finished built 1 benchmark suite(s)
$ cargo codspeed run
Collected 1 benchmark suite(s) to run
Running my_benchmark
Using codspeed-criterion-compat v1.0.0 compatibility layer
NOTICE: codspeed is enabled, but no performance measurement will be made since it's running in an unknown environment.
Checked: benches/bencher_example.rs::fib_20 (group: benches)
Done running bencher_example
Finished running 1 benchmark suite(s)
```
### Not supported:
- `iter_custom`
- `with_filter`