在 .NET 8 中搜尋值的最佳新方法

https://www.bilibili.com/list/watchlater?oid=918750121

using System.Buffers;
using BenchmarkDotNet.Attributes;

namespace SearchValuesExample;

[MemoryDiagnoser(false)]
public class Benchmarks
{
    private const string Base64Chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

    private static readonly char[] Base64CharsArr =
    [
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
        'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
        'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/', '='
    ];

    private static readonly SearchValues<char> Base64SearchVal = SearchValues.Create(Base64Chars);

    [Params("dQw4w9WgXcQ","6iFbuI^pe68k", "dQw4w9WgXcQdQw4w9WgXcQdQw4w9WgXcQdQw4w9WgXcQdQw4w9WgXcQ")]
    public string ExampleText { get; set; }
    
    [Benchmark]
    public bool IsBase64_SearchValues()
    {
        return ExampleText.AsSpan().IndexOfAnyExcept(Base64SearchVal) == -1;
    }
    
    [Benchmark]
    public bool IsBase64_CharArray()
    {
        return ExampleText.AsSpan().IndexOfAnyExcept(Base64CharsArr) == -1;
    }
    
    [Benchmark]
    public bool IsBase64_Naive()
    {
        for (var i = 0; i < ExampleText.Length; i++)
        {
            var chr = ExampleText[i];
            if (!Base64CharsArr.Contains(chr))
            {
                return false;
            }
        }

        return true;
    }
}