Reduce heap allocations in ResolverUtility.FindLibraryByVersionAsync

[kartheekp-ms]

@kartheekp-ms commented on Tue Nov 23 2021

While working on https://github.com/nuget/client.engineering/issues/1057 issue, I noticed that ResolverUtility.FindLibraryByVersionAsync method https://github.com/NuGet/NuGet.Client/blob/a8b6b1fb3a1bccd207a83612cd0f5e1f4ff1d0b8/src/NuGet.Core/NuGet.DependencyResolver.Core/ResolverUtility.cs#L363 has following warnings reported by the PerformanceSensitive analyzers.

Severity	Code	Description	Project	File	Line	Suppression State
Warning	HAA0302	The compiler will emit a class that will hold this as a field to allow capturing of this closure	NuGet.DependencyResolver.Core (net472)	~\NuGet.Client-W1\src\NuGet.Core\NuGet.DependencyResolver.Core\ResolverUtility.cs	365	Active
Warning	HAA0301	Heap allocation of closure Captures: libraryRange,framework,cacheContext,logger,token	NuGet.DependencyResolver.Core (net472)	~\NuGet.Client-W1\src\NuGet.Core\NuGet.DependencyResolver.Core\ResolverUtility.cs	373	Active
Warning	HAA0302	The compiler will emit a class that will hold this as a field to allow capturing of this closure	NuGet.DependencyResolver.Core (net472)	~\NuGet.Client-W1\src\NuGet.Core\NuGet.DependencyResolver.Core\ResolverUtility.cs	423	Active

This method has ~880 MB allocations during solution restore for OrchardCore solution https://github.com/OrchardCMS/OrchardCore/tree/75923732c36d2785cb869affb805f0ff19d1847c

[aortiz-msft]

@kartheekp-ms - Would you please get us memory allocations before and after this change?

[kartheekp-ms]

@aortiz-msft - The heap allocations have reduced by 200 MB after the fix for OrchardCore solution restore scenario. I added more details to the PR description. NuGet/NuGet.Client#4348