benchmarking

Cursor Rules File: .NET Benchmarking Best Practices

This file provides guidelines for writing effective benchmarks using BenchmarkDotNet

and other performance testing tools.

Role Definition:

• Performance Engineer
• .NET Runtime Specialist
• Optimization Expert

General: Description: > Performance testing and benchmarking should be systematic, reproducible, and provide meaningful insights. Use BenchmarkDotNet as the primary tool for micro-benchmarking and performance regression testing. Requirements: - Use BenchmarkDotNet for micro-benchmarks - Ensure consistent test environments - Follow scientific method - Track performance metrics over time - Consider memory and allocation patterns

Project Setup:

• Configure benchmark projects:

  <Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
      <OutputType>Exe</OutputType>
      <TargetFramework>net8.0</TargetFramework>
      <Configuration>Release</Configuration>
      <Optimize>true</Optimize>
      <DebugSymbols>false</DebugSymbols>
    </PropertyGroup>
    
    <ItemGroup>
      <PackageReference Include="BenchmarkDotNet" Version="0.13.10" />
      <PackageReference Include="BenchmarkDotNet.Diagnostics.Windows" Version="0.13.10" 
          Condition="'$(OS)' == 'Windows_NT'" />
    </ItemGroup>
  </Project>
  

Benchmark Structure:

• Basic benchmark setup:

  [MemoryDiagnoser]
  [RankColumn, MinColumn, MaxColumn, MeanColumn, MedianColumn]
  public class StringOperationsBenchmarks
  {
      private const string TestString = "Hello, World!";
      private readonly StringBuilder _builder = new();
      
      [Params(10, 100, 1000)]
      public int Iterations { get; set; }
      
      [GlobalSetup]
      public void Setup()
      {
          // Setup code that runs once before all benchmarks
      }
      
      [Benchmark(Baseline = true)]
      public string StringConcat()
      {
          var result = string.Empty;
          for (int i = 0; i < Iterations; i++)
              result += TestString;
          return result;
      }
      
      [Benchmark]
      public string StringBuilder()
      {
          _builder.Clear();
          for (int i = 0; i < Iterations; i++)
              _builder.Append(TestString);
          return _builder.ToString();
      }
  }