# benchman
[](https://crates.io/crates/benchman)
[](https://docs.rs/benchman)
## Features
- Focus on one-shot benchmark
- RAII-style
- Statistics (Average, Median, 95% and 99% percentile)
- Colored output
- Tagging
- Nesting
## Motivation
I guess there are two types of benchmarks.
One is a benchmark of a small and fast function in which we want the statistics
from a million of iterations. For this type of benchmark, [Criterion.rs](https://github.com/bheisler/criterion.rs) is a good fit.
Another type is what I call one-shot benchmark.
You may have wanted to write a benchmark program like this.
```rust
let mut db = DB::new();
let t = Instant::now();
db.write(...);
println!("write: {:?}", t.elapsed());
let t = Instant::now();
db.read(...);
println!("read: {:?}", t.elapsed());
```
According to [Criterion.rs #531](https://github.com/bheisler/criterion.rs/issues/531), this type of benchmark is infeasible with Criterion.rs because Criterion is focusing on the first type.
That's why I started to create benchman.
## RAII-style measurement
RAII is a good technique to manage resource access.
My idea behind designing benchman is that stopwatch is like a resource
because it is like a producer of a benchmark result that sends the result to the
single central consumer and there is a strict rule that stopwatch shouldn't send the result twice.
With this idea, the library is designed like this.
```rust
let stopwatch = benchman.get_stopwatch("some_tag");
do_something();
drop(stopwatch);
// or
{
let _sw = benchman.get_stopwatch("some_tag");
do_something();
}
```
When the stopwatch is dropped, the measurement result is sent to the central database.
## Author
Akira Hayakawa (@akiradeveloper)