Closed jonathanpeppers closed 2 weeks ago
Profiling an incremental build of a dotnet new maui project with a XAML change, one thing I saw was time spent in <GenerateJavaStubs/> MSBuild task, and the ManifestDocument class:
dotnet new maui
<GenerateJavaStubs/>
ManifestDocument
67.57ms (1.80%) xamarin.android.build.tasks!Xamarin.Android.Tasks.ManifestDocument.Merge(class Microsoft.Build.Utilities.TaskLoggingHel 19.99ms (0.53%) xamarin.android.build.tasks!Xamarin.Android.Tasks.ManifestDocument.CreateApplicationElement(class System.Xml.Linq.XEleme...
Reviewing the code, there was a decent amount of LINQ usage that would create extra allocations for closures, such as:
var properties = Assemblies.SelectMany (path => PropertyAttribute.FromCustomAttributeProvider (Resolver.GetAssembly (path), cache))
I unrolled the System.Linq usage, and just used plain foreach loops instead.
foreach
I also found some places that did:
if (!attrs.Any ()) yield break;
We could just remove these as the yield return wouldn't return if attrs is empty anyway.
yield return
attrs
After removing this code, I see a small improvement:
62.56ms (1.80%) xamarin.android.build.tasks!Xamarin.Android.Tasks.ManifestDocument.Merge(class Microsoft.Build.Utilities.TaskLoggingHe... 16.03ms (0.46%) xamarin.android.build.tasks!Xamarin.Android.Tasks.ManifestDocument.CreateApplicationElement(class System.Xml.Linq.XEleme...
This probably saves ~5ms to incremental builds, but seems like a straightforward change.
Profiling an incremental build of a
dotnet new mauiproject with a XAML change, one thing I saw was time spent in<GenerateJavaStubs/>MSBuild task, and theManifestDocumentclass:Reviewing the code, there was a decent amount of LINQ usage that would create extra allocations for closures, such as:
I unrolled the System.Linq usage, and just used plain
foreachloops instead.I also found some places that did:
We could just remove these as the
yield returnwouldn't return ifattrsis empty anyway.After removing this code, I see a small improvement:
This probably saves ~5ms to incremental builds, but seems like a straightforward change.