Umbraco-CMS/tests/Umbraco.Tests.Benchmarks/ConcurrentDictionaryBenchmarks.cs

using System;
using System.Collections.Concurrent;
using BenchmarkDotNet.Attributes;
using Umbraco.Cms.Core.Collections;

namespace Umbraco.Tests.Benchmarks;

[MemoryDiagnoser]
public class ConcurrentDictionaryBenchmarks
{
    private static readonly ConcurrentDictionary<CompositeTypeTypeKey, bool> AssignableTypeCache = new();

    private static readonly object input = new Bar();

    private static readonly Type source = typeof(Bar);

    private static readonly Type target = typeof(Foo);

    [Benchmark(Baseline = true)]
    public bool GetCachedCanAssignFactory() =>
        AssignableTypeCache.GetOrAdd(new CompositeTypeTypeKey(source, target), k =>
        {
            var ksource = k.Type1;
            var ktarget = k.Type2;

            return ktarget.IsAssignableFrom(ksource) && typeof(IConvertible).IsAssignableFrom(ksource);
        });

    [Benchmark]
    public bool GetCachedCanAssignNoFactory()
    {
        // This method is 10% faster
        var key = new CompositeTypeTypeKey(source, target);
        if (AssignableTypeCache.TryGetValue(key, out bool canConvert))
        {
            return canConvert;
        }

        // "is" is faster than "IsAssignableFrom"
        if (input is IConvertible && target.IsAssignableFrom(source))
        {
            return AssignableTypeCache[key] = true;
        }

        return AssignableTypeCache[key] = false;
    }

    private class Foo : IConvertible
    {
        public TypeCode GetTypeCode() => TypeCode.Object;

        public bool ToBoolean(IFormatProvider provider) => throw new NotImplementedException();

        public byte ToByte(IFormatProvider provider) => throw new NotImplementedException();

        public char ToChar(IFormatProvider provider) => throw new NotImplementedException();

        public DateTime ToDateTime(IFormatProvider provider) => throw new NotImplementedException();

        public decimal ToDecimal(IFormatProvider provider) => throw new NotImplementedException();

        public double ToDouble(IFormatProvider provider) => throw new NotImplementedException();

        public short ToInt16(IFormatProvider provider) => throw new NotImplementedException();

        public int ToInt32(IFormatProvider provider) => throw new NotImplementedException();

        public long ToInt64(IFormatProvider provider) => throw new NotImplementedException();

        public sbyte ToSByte(IFormatProvider provider) => throw new NotImplementedException();

        public float ToSingle(IFormatProvider provider) => throw new NotImplementedException();

        public string ToString(IFormatProvider provider) => throw new NotImplementedException();

        public object ToType(Type conversionType, IFormatProvider provider)
        {
            if (conversionType == typeof(Foo))
            {
                return new Foo();
            }

            throw new NotImplementedException();
        }

        public ushort ToUInt16(IFormatProvider provider) => throw new NotImplementedException();

        public uint ToUInt32(IFormatProvider provider) => throw new NotImplementedException();

        public ulong ToUInt64(IFormatProvider provider) => throw new NotImplementedException();
    }

    private class Bar : Foo
    {
    }
}