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The official Dart project benchmark harness.

Dart CI pub package package publisher

The Dart project benchmark harness is the recommended starting point when building a benchmark for Dart.

Interpreting Results #

By default, the reported runtime in BenchmarkBase is not for a single call to run(), but for the average time it takes to call run() 10 times for legacy reasons. The benchmark harness executes a 10-call timing loop repeatedly until 2 seconds have elapsed; the reported result is the average of the runtimes for each loop. This behavior will change in a future major version.

Benchmarks extending BenchmarkBase can opt into the reporting the average time to call run() once by overriding the exercise method:

  void exercise() => run();

AsyncBenchmarkBase already reports the average time to call run() once.

Comparing Results #

If you are running the same benchmark, on the same machine, running the same OS, the reported run times can be carefully compared across runs. Carefully because there are a variety of factors which could cause error in the run time, for example, the load from other applications running on your machine could alter the result.

Comparing the run time of different benchmarks is not recommended. In other words, don't compare apples with oranges.

Features #

  • BenchmarkBase class that all new benchmarks should extend.
  • AsyncBenchmarkBase for asynchronous benchmarks.
  • Template benchmark that you can copy and paste when building new benchmarks.

Getting Started #

1. Add the following to your project's pubspec.yaml

    benchmark_harness: any

2. Install pub packages

dart pub install

3. Add the following import:

import 'package:benchmark_harness/benchmark_harness.dart';

4. Create a benchmark class which inherits from BenchmarkBase or AsyncBenchmarkBase.

Example #

Create a dart file in the benchmark/ folder of your package.

// Import BenchmarkBase class.
import 'package:benchmark_harness/benchmark_harness.dart';

// Create a new benchmark by extending BenchmarkBase
class TemplateBenchmark extends BenchmarkBase {
  const TemplateBenchmark() : super('Template');

  static void main() {
    const TemplateBenchmark().report();

  // The benchmark code.
  void run() {}

  // Not measured setup code executed prior to the benchmark runs.
  void setup() {}

  // Not measured teardown code executed after the benchmark runs.
  void teardown() {}

  // To opt into the reporting the time per run() instead of per 10 run() calls.
  //void exercise() => run();

void main() {
  // Run TemplateBenchmark

Output #

Template(RunTime): 0.1568472448997197 us.

This is the average amount of time it takes to run run() 10 times for BenchmarkBase and once for AsyncBenchmarkBase.

µs is an abbreviation for microseconds.

Contributions #

This package is carefully curated by the Dart team to exact specifications. Please open an issue with any proposed changes before submitting a pull request.

Publishing automation #

For information about our publishing automation and release process, see

pub points



The official Dart project benchmark harness.

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