Benchmarking

This package provides tools to measure performance of your code. Some features:

  • first-class support both sync and async code
  • a class-based interface (like package:benchmark_harness)
  • a functional interface (like package:test)
  • handles simple micro-benchmarks as well as more complex ones (with setup and teardown functions)

Writing your own bechmarks

To write a benchmark, you just write a run function. If your code needs it, you can also provide setup and teardown functions to prepare the benchmark before executing and clean up afterwards, respectively.

In the following example, we compare element access performance for HashMap and the default Map implementation. Note: if you actually run this benchmark, notice how changing the number of items influences the result.

void main () {
  final numbers = List.generate(10000, (i) => i);
  final map = {for (var n in numbers) n: n.toString()};
  final hashMap = HashMap<int, String>.fromEntries(map.entries);
  final randomizedKeys = numbers.toList()..shuffle();
  String? result; // so that the loop isn't optimized out

  // This is a "functional" benchmark definition.
  // Alternatively, you can define your benchmark as a class, by overriding either SyncBenchmark or AsyncBenchmark.
  syncBenchmark('Map[k]', () => randomizedKeys.forEach((key) => result = map[key]))
      .report(units: numbers.length); // report() takes an optional argument to report "per unit" performance
  syncBenchmark('HashMap[k]', () => randomizedKeys.forEach((key) => result = hashMap[key]))
      .report(units: numbers.length);
}

A result of running the benchmark would look something like:

$ dart run example/benchmarking.dart

Map[k]
          total runs:    8 384
          total time:   2.0002  s
         average run:      238 μs
         runs/second:  4 201.7
               units:   10 000
        units/second:  4 201.7
       time per unit:   0.0238 μs

HashMap[k]
          total runs:   16 459
          total time:   2.0000  s
         average run:      121 μs
         runs/second:  8 264.5
               units:   10 000
        units/second:  8 264.5
       time per unit:   0.0121 μs

Libraries

benchmarking