<h1 align="center">Calliper</h1>
Calliper is a Callgrind-based benchmarking harness with few-too-many knobs sticking out.
[![Docs](https://docs.rs/calliper/badge.svg)](https://docs.rs/calliper)
**State**: There's still a lot to do, but Calliper should be usable now. Note that I plan to break API prior to 1.0.0 arbitrarily in minor versions.
## Table of contents
- [Table of contents](#table-of-contents)
- [Usage](#usage)
- [Examples](#examples)
- [License](#license)
- [Acknowledgmenets](#acknowledgements)
## Usage
To use Calliper, you must have [Valgrind](https://valgrind.org/) installed.
To write your first benchmark with Calliper, add the following to your `Cargo.toml`:
```toml
[dev-dependencies]
calliper = "0.1.4"
[[bench]]
name = "my_first_calliper_benchmark"
harness = false
```
Then, create a file at `$PROJECT/benches/my_first_calliper_benchmark.rs` with the following contents:
```rust
use calliper::utils::black_box;
use calliper::{Runner, Scenario};
#[inline(never)]
#[no_mangle]
fn binary_search_impl(haystack: &[u8], needle: u8) -> Result<usize, usize> {
haystack.binary_search(&needle)
}
fn bench_binary_search() {
let range = (0..255).collect::<Vec<_>>();
let _ = black_box(binary_search_impl(black_box(&range), black_box(253)));
}
#[inline(never)]
#[no_mangle]
fn linear_search_impl(haystack: &[u8], needle: u8) -> Option<usize> {
haystack.iter().position(|n| *n == needle)
}
fn bench_linear_search() {
let range = (0..255).collect::<Vec<_>>();
black_box(linear_search_impl(black_box(&range), black_box(253)));
}
fn main() -> Result<(), Box<dyn std::error::Error>> {
let runner = Runner::default();
let benches = [
Scenario::new(bench_linear_search),
Scenario::new(bench_binary_search),
];
if let Some(results) = runner.run(&benches)? {
for res in results.into_iter() {
println!("{}", res.parse());
}
}
Ok(())
}
```
Now the benchmark can be executed with `cargo bench`.
More sophisticated examples can be found in benches folder of this repository.
## License
This project is licensed under either of
* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
https://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) or
https://opensource.org/licenses/MIT)
at your option.
## Acknowledgements
Calliper is inspired by [Iai benchmarking harness](https://github.com/bheisler/iai).