From 8309a5c5aeb90a223222792f9c72f82b834ed7bd Mon Sep 17 00:00:00 2001
From: Elie Bariche <33458222+ebariche@users.noreply.github.com>
Date: Tue, 4 Apr 2023 15:22:01 -0400
Subject: [PATCH] perf: Add GetBootTime binding

---
 .../UI/Xaml/Input/PointerRoutedEventArgs.wasm.cs      |  2 +-
 src/Uno.UI/UI/Xaml/WindowManagerInterop.wasm.cs       | 11 +++++++++++
 src/Uno.UI/ts/WindowManager.ts                        |  7 +++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/Uno.UI/UI/Xaml/Input/PointerRoutedEventArgs.wasm.cs b/src/Uno.UI/UI/Xaml/Input/PointerRoutedEventArgs.wasm.cs
index d4d9f1676598..934cc147e652 100644
--- a/src/Uno.UI/UI/Xaml/Input/PointerRoutedEventArgs.wasm.cs
+++ b/src/Uno.UI/UI/Xaml/Input/PointerRoutedEventArgs.wasm.cs
@@ -110,7 +110,7 @@ private PointerPointProperties GetProperties()
 
 		private static ulong ToTimeStamp(double timestamp)
 		{
-			_bootTime ??= (ulong)(double.Parse(WebAssemblyRuntime.InvokeJS("Date.now() - performance.now()"), CultureInfo.InvariantCulture) * TimeSpan.TicksPerMillisecond);
+			_bootTime ??= (ulong)(WindowManagerInterop.GetBootTime() * TimeSpan.TicksPerMillisecond);
 
 			return _bootTime.Value + (ulong)(timestamp * TimeSpan.TicksPerMillisecond);
 		}
diff --git a/src/Uno.UI/UI/Xaml/WindowManagerInterop.wasm.cs b/src/Uno.UI/UI/Xaml/WindowManagerInterop.wasm.cs
index 86c82f1a9070..3c50f35a2d89 100644
--- a/src/Uno.UI/UI/Xaml/WindowManagerInterop.wasm.cs
+++ b/src/Uno.UI/UI/Xaml/WindowManagerInterop.wasm.cs
@@ -55,6 +55,14 @@ internal static string FindLaunchArguments()
 				WebAssemblyRuntime.InvokeJS("Uno.UI.WindowManager.findLaunchArguments()");
 #endif
 
+		internal static double GetBootTime()
+			=>
+#if NET7_0_OR_GREATER
+				NativeMethods.GetBootTime();
+#else
+				double.Parse(WebAssemblyRuntime.InvokeJS("Date.now() - performance.now()"), CultureInfo.InvariantCulture);
+#endif
+
 		#region CreateContent
 		internal static void CreateContent(IntPtr htmlId, string htmlTag, IntPtr handle, int uiElementRegistrationId, bool htmlTagIsSvg, bool isFocusable)
 		{
@@ -1294,6 +1302,9 @@ internal static partial void ArrangeElement(
 			[JSImport("globalThis.Uno.UI.WindowManager.findLaunchArguments")]
 			internal static partial string FindLaunchArguments();
 
+			[JSImport("globalThis.Uno.UI.WindowManager.getBootTime")]
+			internal static partial double GetBootTime();
+
 			[JSImport("globalThis.Uno.UI.WindowManager.current.focusView")]
 			internal static partial void FocusView(IntPtr htmlId);
 
diff --git a/src/Uno.UI/ts/WindowManager.ts b/src/Uno.UI/ts/WindowManager.ts
index 93c34c08dbe7..4d334d88b60d 100644
--- a/src/Uno.UI/ts/WindowManager.ts
+++ b/src/Uno.UI/ts/WindowManager.ts
@@ -205,6 +205,13 @@ namespace Uno.UI {
 			}
 		}
 
+		/**
+			* Estimated application startup time
+			*/
+		public static getBootTime(): number {
+			return Date.now() - performance.now();
+		}
+
 		/**
 			* Create a html DOM element representing a Xaml element.
 			*