Benchmark Scratchpad

A quick scratchpad for benchmarking Rust code

Prerequisites

• cargo-make - cargo install --force cargo-make

Instructions

1. Edit benches/benchmark.rs
2. Run cargo make bench

benchmarks!

The benchmarks! macro accepts input with the following structure:

benchmarks! {
  benchmark_name { /* benchmark impl */ }
  other_benchmark_name { /* other benchmark impl */ }
}

The criterion.rs black_box function is included and usable within the macro.

criterion::black_box stops the compiler from constant-folding away the whole function and replacing it with a constant.

You can you the keyword @skip before a benchmark for it not to be run:

benchmarks! {
  @skip benchmark_name { /* benchmark impl */ }
}

Tasks

• cargo make bench - runs the benchmark via cargo-criterion
• cargo make bench-verbose - runs the benchmark via cargo-criterion with verbose output
• cargo make reset - resets the criterion data for earlier benchmarks
• cargo make new - returns benches/benchmark.rs to the initial state
• cargo make save [FILENAME] - saves the contents of benches/benchmark.rs to saved/[FILENAME].rs

Example

mod internals;

benchmarks! {
    collect_vec_string {
        let vector = black_box(vec!["hello", "world"]);
        let _output = vector
            .iter()
            .map(|item| item.to_uppercase())
            .collect::<Vec<String>>()
            .join("");
    }

    collect_string {
        let vector = black_box(vec!["hello", "world"]);
        let _output = vector
            .iter()
            .map(|item| item.to_uppercase())
            .collect::<String>();
    }
}

Uses

• cargo-make
• cargo-criterion
• criterion.rs