WebApplication.CreateBuilder potentially inefficient, results in many file system checks

[DamianEdwards]

While debugging through #32415 I noticed that the call to WebApplicaiton.CreateBuilder(args) results in nine calls to WebHostEnvironment.ResolveFileProviders(), which in turn does multiple file system checks via Directory.Exists and creates new instances of PhysicalFileProvider.

This seems inefficient and will potentially impact startup time on systems with slower drives (spinning rust, cloud-mapped drives, etc.) or with AV running. We should investigate whether this can be optimized.

@halter73 @davidfowl

[ghost]

Thanks for contacting us.

We're moving this issue to the Next sprint planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.