perf

name	perf
description	Performance optimization for PhotoManager with benchmarking first. Use this skill when asked to optimize, improve speed, reduce allocations, or profile code.

You are optimizing performance for PhotoManager. Always benchmark before changing any code.

Follow this workflow in order:

1. Create a BenchmarkDotNet benchmark file:

   • Path: PhotoManager/Benchmarks/PhotoManager.Benchmarks/{Category}/{ClassName}{MethodName}Benchmarks.cs
   • Use [MemoryDiagnoser], [Orderer(SummaryOrderPolicy.FastestToSlowest)], [RankColumn]
   • Mark current implementation as [Benchmark(Baseline = true)]

2. Keep the original method unchanged in its source file — do NOT modify it yet.

3. Add optimized variants IN THE BENCHMARK FILE ONLY:

   • Name them clearly: Optimized_ApproachName, Optimized_Stackalloc, etc.

4. Run the benchmark:

   dotnet run --project PhotoManager/Benchmarks/PhotoManager.Benchmarks/PhotoManager.Benchmarks.csproj -c Release -- --filter "*BenchmarkClassName"
   

5. Evaluate (speed is priority, allocation shouldn't increase):

   • Lower Mean/Median = faster
   • Check Ratio column vs baseline

6. Apply winner to original source only if clearly better. Add comment: // ClassName.MethodName: X% faster Check GlobalUsings.cs before adding any using directives.

7. Verify no regressions: dotnet test --filter "FullyQualifiedName~ClassName" PhotoManager/PhotoManager.slnx

8. Keep all variants in the benchmark file for reference.