change_notifier_vs_state_notifier.dart

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

import 'change_notifier.dart';

class MyChangeNotifier extends ChangeNotifier {
  int _value;
  int get value => _value;
  set value(int value) {
    _value = value;
    notifyListeners();
  }
}

// Create a new benchmark by extending BenchmarkBase
class ChangeNotifierBenchmark extends BenchmarkBase {
  ChangeNotifierBenchmark(this.listenerCount)
      : super('ValueNotifier(listenerCount: $listenerCount');

  final int listenerCount;

  MyChangeNotifier notifier;

  // The benchmark code.
  @override
  void run() {
    for (var i = 0; i < 100; i++) {
      notifier.value = i;
    }
  }

  // Not measured setup code executed prior to the benchmark runs.
  @override
  void setup() {
    notifier = MyChangeNotifier();
    for (var i = 0; i < listenerCount; i++) {
      notifier.addListener(() {});
    }
  }

  // Not measured teardown code executed after the benchmark runs.
  @override
  void teardown() {
    notifier.dispose();
    notifier = null;
  }
}

class StateNotifierBenchmark extends BenchmarkBase {
  StateNotifierBenchmark(this.listenerCount)
      : super('StateNotifier(listenerCount: $listenerCount');

  final int listenerCount;

  MyNotifier notifier;

  // The benchmark code.
  @override
  void run() {
    for (var i = 0; i < 100; i++) {
      notifier.state = i;
    }
  }

  // Not measured setup code executed prior to the benchmark runs.
  @override
  void setup() {
    notifier = MyNotifier();
    for (var i = 0; i < listenerCount; i++) {
      notifier.addListener((value) {});
    }
  }

  // Not measured teardown code executed after the benchmark runs.
  @override
  void teardown() {
    notifier.dispose();
    notifier = null;
  }
}

class MyNotifier extends StateNotifier<int> {
  MyNotifier() : super(0);
}

main() {
  ChangeNotifierBenchmark(0).report();
  ChangeNotifierBenchmark(1).report();
  ChangeNotifierBenchmark(2).report();
  ChangeNotifierBenchmark(3).report();
  ChangeNotifierBenchmark(4).report();
  ChangeNotifierBenchmark(5).report();

  print('');

  StateNotifierBenchmark(0).report();
  StateNotifierBenchmark(1).report();
  StateNotifierBenchmark(2).report();
  StateNotifierBenchmark(3).report();
  StateNotifierBenchmark(4).report();
  StateNotifierBenchmark(5).report();
}