PerformanceTester

Install-Package SoftCircuits.PerformanceTester

Introduction

PerformanceTester is a simple library to help compare the performance of different algorithms. If you have several ways of solving a problem where performance is a concern, use this library as a framework to quickly show the relative performance of different candidates.

Creating Tests

You create a test by creating a class that implements IPerformanceTest. This interface has three members:

public string Description { get; }

Description is a read-only property that describes this test.

public void Initialize(object? data);

Initialize is a method to perform any initialization for the test. The time taken by this method is not included in the results. The data argument can optionally be used to pass data to the test.

public void Run(object? data);

Run is the method that performs the actual test. This is the method that will be timed. The data argument can optionally be used to pass data to the test.

The following code defines three simple tests. These tests simply call Thread.Sleep() to pause for varying amounts of time.

class Test1 : IPerformanceTest
{
    public string Description => "Quarter second test";
    public void Initialize(object? data) { }
    public void Run(object? data) => Thread.Sleep(250);
}

class Test2 : IPerformanceTest
{
    public string Description => "Half second test";
    public void Initialize(object? data) { }
    public void Run(object? data) => Thread.Sleep(500);
}

class Test3 : IPerformanceTest
{
    public string Description => "One second test";
    public void Initialize(object? data) { }
    public void Run(object? data) => Thread.Sleep(1000);
}

Running the Tests

To test the performance of the tests you've created, create an instance of the PerformanceTester class and call the Run() method. This method has many overloads to support different scenarios. Often, the easiest way to call this method is by providing the current assembly. In this case, the Run() method will run all the tests (classes that implement IPerformanceTest) in the given assembly.

PerformanceTester tester = new PerformanceTester();
IEnumerable<TestResult> results = tester.Run(Assembly.GetExecutingAssembly());

Most of the Run() overloads include an optional iterations and data argument.

The iterations argument specifies how many times to run each test. This can be handy when the test is too quick to measure, or if the test execution time can vary and you want to compare the average time to perform each test. When running more than one iteration, you can set the PerformanceTester.AverateResults property to true. In this case, the results will show the average time rather than the total time.

The data argument is simply an argument that gets pass to each test. You might using for sending test data, for example. Because this argument is of type object, it can pass any type of data.

Displaying Test Results

The Run() methods return an IEnumerable of type TestResult. The TestResult class provides the description of the test, the number of milliseconds taken by that test, and also the percent of time taken relative to the slowest test.

The TestResult class also provides the GetRelativePerformanceBar() method. This method will create a character bar that represents the result's relative time. This is demonstrated in the following snippet.

foreach (TestResult result in results)
{
    Console.WriteLine("{0} ({1}ms)", result.Description, result.Milliseconds);
    Console.WriteLine("[{0}]", result.GetRelativePerformanceBar(60));
    Console.WriteLine();
}

The code above produces the following output.

Quarter second test (255ms)
[***************                                             ]

Half second test (500ms)
[*****************************                               ]

One second test (1001ms)
[************************************************************]