ArrayReadBenchmark.cs

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Jobs;

namespace Storage.Benchmark;

[SimpleJob(RuntimeMoniker.Net60)]
[SimpleJob(RuntimeMoniker.NetCoreApp31)]
[SimpleJob(RuntimeMoniker.Net48)]
[MeanColumn]
public class ArrayReadBenchmark
{
    [Benchmark]
    public int For()
    {
        var sum = 0;
        for (var i = 0; i < _array.Length; i++)
        {
            sum += _array[i];
        }

        return sum;
    }

    [Benchmark(Baseline = true)]
    public int Foreach()
    {
        var sum = 0;
        foreach (var element in _array)
        {
            sum += element;
        }

        return sum;
    }

    [Benchmark]
    public int ForeachCustom()
    {
        var sum = 0;
        foreach (var element in new ArrayEnumerator<int>(_array))
        {
            sum += element;
        }

        return sum;
    }

    [Benchmark]
    public int ForeachSpan()
    {
        var sum = 0;
        foreach (var element in _array.AsSpan())
        {
            sum += element;
        }

        return sum;
    }

    [Benchmark]
    public unsafe int Unsafe()
    {
        var sum = 0;
        fixed (int* arrayPtr = &_array[0])
        {
            for (var index = 0; index < _array.Length; index++)
            {
                sum += *(arrayPtr + index);
            }
        }

        return sum;
    }

    [Benchmark]
    public unsafe int UnsafeFixed()
    {
        var sum = 0;
        fixed (int* arrayPtr = _array)
        {
            var ptr = arrayPtr;
            var endPtr = arrayPtr + _array.Length;
            while (ptr < endPtr)
            {
                sum += *ptr++;
            }
        }

        return sum;
    }

    #region Configuration

    private int[] _array = null!;

    [GlobalSetup]
    public void Init()
    {
        const int count = 1021;

        _array = new int[count];

        var rnd = new Random(1234);
        for (var i = 0; i < count; i++)
        {
            _array[i] = rnd.Next(0, 10);
        }
    }

    #endregion
}