criterion.rs

Criterion.rs: A Comprehensive Guide to Microbenchmarking in Rust

Introduction

Criterion.rs is a powerful and easy-to-use library designed to assist developers in measuring the precise performance of their Rust code. It helps in identifying small performance improvements or regressions quickly and accurately, allowing developers to optimize their code with confidence. By leveraging statistical analysis, Criterion.rs stands out as a reliable tool for microbenchmarking, making it indispensable for anyone keen on performance tuning in Rust.

Features

Criterion.rs boasts a range of features that make it a popular choice for developers:

• Statistics: It employs rigorous statistical analysis to detect performance changes since the last benchmark run. This ensures that developers have a clear and accurate view of their code's performance.
• Charts: The use of gnuplot enables the generation of detailed graphs of benchmark results, providing visual insight into performance metrics.
• Stable-compatible: One of its standout features is the ability to benchmark code without requiring the nightly version of Rust, making it suitable for stabilized environments.

Quickstart Guide

Getting started with Criterion.rs is straightforward. Developers need to ensure they have gnuplot installed, which is essential for generating plots. Here’s a concise setup guide:

1. Add Criterion.rs to your project: Insert the following into your Cargo.toml:

   [dev-dependencies]
   criterion = { version = "0.5", features = ["html_reports"] }
   
   [[bench]]
   name = "my_benchmark"
   harness = false
   

2. Define a Benchmark: Create a file at $PROJECT/benches/my_benchmark.rs with the desired benchmark code. Here's a sample:

   use std::hint::black_box;
   use criterion::{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);
   

3. Run the Benchmark: Execute the benchmark with cargo bench. The output will provide detailed performance metrics, indicating any variances and outliers in the measurements.

Goals

The primary goal of Criterion.rs is to offer a statistically rigorous tool for measuring code performance. It aims to prevent performance regressions while accurately measuring optimizations. The library is designed to be user-friendly, allowing even those without advanced statistical knowledge to create effective benchmarks.

Contribution and Community

Criterion.rs thrives on community contributions. Users are encouraged to report their experiences, suggest enhancements, and contribute to code or documentation. Not sure where to begin? The Beginner label on GitHub is an excellent starting point for newcomers eager to contribute.

Compatibility and Maintenance

Criterion.rs supports the last three stable minor releases of Rust, ensuring it remains accessible and functional with newer developments in the language. The library was initially created by Jorge Aparicio and is currently maintained by Brook Heisler.

Licensing

The library is dual-licensed under the Apache 2.0 and MIT licenses, providing flexibility in how it can be used within projects.

Related Projects and Extensions

Criterion.rs is part of a larger ecosystem of benchmarking tools and extensions:

• Related Projects:

  • Bencher: A port that enables benchmark running on stable Rust.
  • Criterion (Haskell): The library that inspired Criterion.rs’s development.

• Extensions:

  • criterion-cycles-per-byte: A plugin to count CPU cycles used during benchmarks.
  • criterion-perf-events: Tracks performance events generated by benchmarks.

Criterion.rs embodies a robust solution for Rust developers focused on performance optimization, offering a thorough approach to microbenchmarking with statistical precision and ease of use.