// Copyright 2014 The Flutter Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. import 'dart:html' as html; import 'dart:typed_data'; import 'dart:ui' as ui; import 'recorder.dart'; // Measures the performance of image decoding. // // The benchmark measures the decoding latency and not impact on jank. It // cannot distinguish between blocking and non-blocking decoding. It naively // measures the total time it takes to decode image frames. For example, the // WASM codecs execute on the main thread and block the UI, leading to jank, // but the browser's WebCodecs API is asynchronous running on a separate thread // and does not jank. However, the benchmark result may be the same. // // This benchmark does not support the HTML renderer because the HTML renderer // cannot decode image frames (it always returns 1 dummy frame, even for // animated images). class BenchImageDecoding extends RawRecorder { BenchImageDecoding() : super( name: benchmarkName, useCustomWarmUp: true, ); static const String benchmarkName = 'bench_image_decoding'; // These test images are taken from https://github.com/flutter/flutter_gallery_assets/tree/master/lib/splash_effects static const List<String> _imageUrls = <String>[ 'assets/packages/flutter_gallery_assets/splash_effects/splash_effect_1.gif', 'assets/packages/flutter_gallery_assets/splash_effects/splash_effect_2.gif', 'assets/packages/flutter_gallery_assets/splash_effects/splash_effect_3.gif', ]; final List<Uint8List> _imageData = <Uint8List>[]; @override Future<void> setUpAll() async { if (_imageData.isNotEmpty) { return; } for (final String imageUrl in _imageUrls) { final html.Body image = await html.window.fetch(imageUrl) as html.Body; _imageData.add((await image.arrayBuffer() as ByteBuffer).asUint8List()); } } // The number of samples recorded so far. int _sampleCount = 0; // The number of samples used for warm-up. static const int _warmUpSampleCount = 5; // The number of samples used to measure performance after the warm-up. static const int _measuredSampleCount = 20; @override Future<void> body(Profile profile) async { await profile.recordAsync('recordImageDecode', () async { final List<Future<void>> allDecodes = <Future<void>>[ for (final Uint8List data in _imageData) _decodeImage(data), ]; await Future.wait(allDecodes); }, reported: true); _sampleCount += 1; if (_sampleCount == _warmUpSampleCount) { profile.stopWarmingUp(); } if (_sampleCount >= _warmUpSampleCount + _measuredSampleCount) { profile.stopBenchmark(); } } } Future<void> _decodeImage(Uint8List data) async { final ui.Codec codec = await ui.instantiateImageCodec(data); const int decodeFrameCount = 5; if (codec.frameCount < decodeFrameCount) { throw Exception( 'Test image contains too few frames for this benchmark (${codec.frameCount}). ' 'Choose a test image with at least $decodeFrameCount frames.' ); } for (int i = 0; i < decodeFrameCount; i++) { (await codec.getNextFrame()).image.dispose(); } codec.dispose(); }