import 'dart:io' as io; import 'dart:typed_data'; import 'package:benchmark_harness/benchmark_harness.dart'; /// Benchmark for creating a [Uint8List] from a list of bytes. /// /// Shows that [Uint8List.new] is ~10x faster than [Uint8List.fromList]. void main() { _Uint8ListFromList().report(); _Uint8ListWithLength().report(); } final class _Uint8ListFromList extends BenchmarkBase { _Uint8ListFromList() : super('Uint8List.fromList'); late Uint8List _list; @override void run() { _list = Uint8List.fromList([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]); } @override void teardown() { // Use the list so it is not optimized away. _writeBytesAvoidDeopt(_list); } } final class _Uint8ListWithLength extends BenchmarkBase { _Uint8ListWithLength() : super('Uint8List.withLength'); late Uint8List _list; @override void run() { final list = Uint8List(10); list[0] = 0; list[1] = 1; list[2] = 2; list[3] = 3; list[4] = 4; list[5] = 5; list[6] = 6; list[7] = 7; list[8] = 8; list[9] = 9; _list = list; } @override void teardown() { // Use the list so it is not optimized away. _writeBytesAvoidDeopt(_list); } } void _writeBytesAvoidDeopt(Uint8List list) { final tmpDir = io.Directory.systemTemp.createTempSync('nox.benchmark'); final file = io.File( '${tmpDir.path}${io.Platform.pathSeparator}nox.benchmark', ); file.writeAsBytesSync(list); file.deleteSync(); tmpDir.deleteSync(); }