[Epic] Performance improvements

[jeromelaban]

Unsorted

• Filter upri embedded using XAML trimmer linker hints #18610

• StatusBar.PhysicalToLogicalPixels() should cache density or use ViewHelper on Android
  

• Remove Json.NET in Lottie addin
  

• INITIAL_MEMORY emcc flag guidance

• Merge embedded resources (localization)

Sorted by order of priority

• Avoid hashing two times to insert in HashtableEx (See: CollectionsMarshal.GetValueRefOrAddDefault<TKey,TValue>)
• Fine tune DependencyPropertyDetails arraypool
• [WASM] Support for image of type "blob:" #10772
• Reduce ContentRoot enumerator allocations #15804
• [Performance] Avoid LINQ in TextBlock.UpdateHyperlinks #15805
• [Perf][Regression] Unnecessary boxing allocations when an element is added to visual tree #16814
• [Performance] Avoid unnecessary predicate allocations in RecyclePool.TryGetElementCore #15806
• perf: Avoid capturing lambdas for BindingPropertyHelper.Convert callsites #15803
• DependencyObjectStore.IsAncestor should use hash set pool #13108
• Unify MemoryManager on all platforms #13129
• Replace usages of Array.Clear(arr, 0, arr.Length) with Array.Clear(arr) #13136
• AncestorsDictionary should be pooled #13110
• Reduce allocations in XamlMember.ToString #13232
• XamlMember.GetHashCode allocates lots of strings #13228
• [Perf] Refactor the VisualTreeHelper.FindElementsInHostCoordinates #13281
• Lots of allocations from TextBlock rendering on Skia #13825
• Dopes sample appear to have a memory leak #13822
• Implement DebugSettings #13947
• [Android] ComboBox should initialize popup lazily #8925
• [Wasm] Remove XamlHandle in favor Id in DOM elements
• [Wasm] Remove XamlType (make it a feature flag)
• [Perf] [Android][Skia] ListView re-layouted multiple times #12081
• TextBlock rich layout uses Obtain and explicit managed builder invocations
• RemoteControl initialization should be done in the background (devloop improvement)
• [Skia] DataGrid VerticalScrollBar inverted, slow, and jerky when scrolling with mouse #9068
• TypeManager.CreateProxy does not cache constructor reflection dotnet/android#7479
• XAML Resource Trimming for net6 Mobile and Skia targets #9010
• Adjust CoreDispatcher scheduling method (front or back push, VBL batching?)
• [android] ViewHelper must use DisplayInformation
• [Android] FrameworkElement.TryCreateKeyRegistration is registering add_KeyPress (causing JNI interop) perf(paintpool): Avoid unnecessary managed/unmanaged transitions #8882
• Avoid RegisterPropertyChangedCallback in AssignAndObserveBrush and use override instead #8891
• Reduce accesses of TextBlock.Inlines #13824
• Migrate string based pieces to Span where appropriate
• Generate slim android bindings for UI APIs (Related perf(android): Use specialized code for layout interop #10429)
• Ensure that Ordinal based comparisons are used most of the time
• ConerRadiusFilter should not be created eagerly during fluent resources initialization
• [Android] TextBoxView.SetCursorColor is creating a BlendModeColorFilter (Could it be pooled ?)
• NativeInstanceHelper should delegate its initialization (particularly the GetFolderPath invocation)
• FrameworkElement.PerformOnLoaded uses get_Parent and be able to use a cached value?
• [Android] TextBlock uses View.ImportantForAccessibility and should be using a default value
• NumberBox should be able to use OnKeyDown override instead of registering to the KeyDown event?
• [Android] Investigate Glide performance #9007
• [Android] Changing TextBlock.Text is expensive
• [Android] Changing TextBlock.Foreground is expensive
• [Android][iOS] GridDeepResizeBenchmark is expensive

Done

• Refactor CoreDispatcher to internally use DispatcherQueue #10301
• reduce allocation
  

  uno/src/Uno.UI/UI/Xaml/DependencyObjectStore.cs

  Line 1561 in befbc54

  store.OnParentPropertyChangedCallback(instanceRef, prop, new DependencyPropertyChangedEventArgs(

• Use Array.fill instead of Copy (perf: Use Span CopyTo instead of Array CopyTo for better performance #13132)
• [Android] Reuse Paint instances #13258
• [Wasm] Improve performance using JSImport/JSExport net7.0 #10622
• Performance regression with Harfbuzz linux
• Wasm SetProperty should not allocate an array for single property changes
• Adjust converters to avoid using [DefaultConversionExtensions] (

  uno/src/Uno.UI/DataBinding/BindingPropertyHelper.cs

  Line 1094 in 96df4c1

  private static object ConvertWithConvertionExtension(object? value, Type? t)

  ) perf: Avoid using DefaultConversionExtensions #12700
• GetWinuiThemeResourceUri should not be formatting a string (perf: GetWinUIThemeResourceUrl shouldn't format a string #11991)
• Adjust regex usage in AndroidResourceNameEncoder (Use net7 generated regexes?) (perf: Avoid using Regex in AndroidResourceNameEncoder #11990)
• [iOS] Border recreate when nothing to draw
  
• [Android] Resource trimming
• [Wasm] Investigate potential perf improvement by using the CSS contain #8872
• iOS get_Scale
  
• [Perf] Generate the code code DrawableHelper.Drawables to avoid reflection on the Resources class #8923
• SelectorItem.UpdateCommonStates uses DateTime.Now causing expensive ICU work perf(selectoritem): Use monotonic clock instead of DateTime.Now #8824
• Remove all RegisterLoadAction uses (Use OnLoaded / OnUnloaded instead) perf: Remove LoadActions #8734
• [Android] InnerBuildPaint should be moved to java to reduce the interop calls java perf(paintpool): Avoid unnecessary managed/unmanaged transitions #8882
• GTK dispatcher is very slow (not easilr changeable because of GTK internals)
• [Perf]Microsoft.UI.Xaml.Controls.BorderLayerRenderer.InnerCreateLayers(...) is slow on Android #10241
• [Perf]UIElement.AdjustCornerRadius(Canvas, CornerRadius) is slow on Android #10253

[spouliot]

I can't edit the issue but iOS get_Scale should not be happening anymore since #9114 was merged (and calls to UIScreen.MainScreen are cached).