This repo demonstrates the effects to performance when using the Results pattern.
- It users C# as programming language.
- It references https://github.com/altmann/FluentResults for an implementation of the Results pattern.
- Benchmarks are implemented using BenchmarkDotNet https://github.com/dotnet/BenchmarkDotNet
- It uses VS 2022 as development environment. But one can easily also use the dotnet cli and any test editor.
The task is to solve the quadratic equation 0 = axx + b*x + c
With d=b*b - 4*a*c one gets two possible solutions x1=(-b+sqrt(d))/2a and x2=(-b-sqrt(d))/2a, assuming a is not zero.
The general solution requires Complex number for the case that d<0.
Very often only then non complex solutions are of interest. So one would first compute d and check if it is less then zero.
In that case there are no real solutions.
This could be handled in the following ways: 1.) BenchmarkQuadraticEquationUsingBoolAndOut: Return a bool that indicates if real solutions exists and return the two solutions using ref parameters 2.) BenchmarkQuadraticEquationUsingResult: Return a Results object which is either an instance of Error (with an optional message) or an instance of Result<(double, double>). 3.) BenchmarkQuadraticEquationUsingException: Return a tuple (double, double) if d is >=0 or throw an argument exception. 4.) BenchmarkQuadraticEquationUsingComplex: Return a tuple (Complex, Complex) which will always work 5.) BenchmarkQuadraticEquationOneOf: Return a tuple (double,double) or (Complex, Complex) depending if a real solutions exists. This saves computing the complex square root
The test code allows to define N (the number of test) cases and the parameter ComplexSolutionPercentage. ComplexSolutionPercentage is the upper limit how man test inputs will yield a complex solution.
Here are some test results:
BenchmarkDotNet v0.14.0, Windows 11 (10.0.22631.4460/23H2/2023Update/SunValley3)
12th Gen Intel Core i9-12900K, 1 CPU, 24 logical and 16 physical cores
.NET SDK 9.0.101
[Host] : .NET 8.0.11 (8.0.1124.51707), X64 RyuJIT AVX2
DefaultJob : .NET 8.0.11 (8.0.1124.51707), X64 RyuJIT AVX2
| Method | N | ComplexSolutionPercentage | Mean | Error | StdDev | Median | Gen0 | Allocated |
|---|---|---|---|---|---|---|---|---|
| BenchmarkQuadraticEquationUsingResult | 1000 | 0 | 7.224 μs | 0.1405 μs | 0.1173 μs | 7.228 μs | 4.0741 | 64000 B |
| BenchmarkQuadraticEquationUsingBoolAndOut | 1000 | 0 | 2.820 μs | 0.0138 μs | 0.0122 μs | 2.820 μs | - | - |
| BenchmarkQuadraticEquationUsingException | 1000 | 0 | 2.952 μs | 0.0147 μs | 0.0123 μs | 2.951 μs | - | - |
| BenchmarkQuadraticEquationUsingComplex | 1000 | 0 | 7.188 μs | 0.1436 μs | 0.2477 μs | 7.304 μs | - | - |
| BenchmarkQuadraticEquationUsingOneOf | 1000 | 0 | 7.152 μs | 0.0607 μs | 0.0568 μs | 7.162 μs | - | - |
| BenchmarkQuadraticEquationUsingResult | 1000 | 0.01 | 7.971 μs | 0.1593 μs | 0.1705 μs | 8.004 μs | 4.0741 | 64000 B |
| BenchmarkQuadraticEquationUsingBoolAndOut | 1000 | 0.01 | 2.854 μs | 0.0135 μs | 0.0126 μs | 2.857 μs | - | - |
| BenchmarkQuadraticEquationUsingException | 1000 | 0.01 | 44.743 μs | 0.2147 μs | 0.1904 μs | 44.683 μs | 0.2441 | 4680 B |
| BenchmarkQuadraticEquationUsingComplex | 1000 | 0.01 | 7.132 μs | 0.0495 μs | 0.0438 μs | 7.122 μs | - | - |
| BenchmarkQuadraticEquationUsingOneOf | 1000 | 0.01 | 7.994 μs | 0.0497 μs | 0.0465 μs | 7.982 μs | - | - |
| BenchmarkQuadraticEquationUsingResult | 1000 | 0.1 | 8.568 μs | 0.1705 μs | 0.1595 μs | 8.565 μs | 4.0741 | 64000 B |
| BenchmarkQuadraticEquationUsingBoolAndOut | 1000 | 0.1 | 2.797 μs | 0.0087 μs | 0.0082 μs | 2.798 μs | - | - |
| BenchmarkQuadraticEquationUsingException | 1000 | 0.1 | 284.535 μs | 1.6312 μs | 1.5258 μs | 284.861 μs | 1.9531 | 31320 B |
| BenchmarkQuadraticEquationUsingComplex | 1000 | 0.1 | 8.114 μs | 0.0555 μs | 0.0492 μs | 8.125 μs | - | - |
| BenchmarkQuadraticEquationUsingOneOf | 1000 | 0.1 | 7.950 μs | 0.0542 μs | 0.0481 μs | 7.967 μs | - | - |