ConcurrentDictionary.TryGetValue comparison by key types.

ConcurrentDicitionaryKeyTypeBench.cs

// This benchmark use one record and TryGetValue returns true.
// Results will be affected by record num and whether match any record or not.

using System.Collections.Concurrent;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

BenchmarkRunner.Run<ConcurrentDictionaryBench>();

record C1(string a, int b, string c);
record struct S2(string a, int b);
record C2(string a, int b);
[MemoryDiagnoser]
// [ShortRunJob]
public class ConcurrentDictionaryBench
{
    private static readonly ConcurrentDictionary<(string, int), C1> dic1 = new();
    private static readonly ConcurrentDictionary<string, C1> dic2 = new();
    private static readonly ConcurrentDictionary<Tuple<string, int>, C1> dic3 = new();
    private static readonly ConcurrentDictionary<S2, C1> dic4 = new();
    private static readonly ConcurrentDictionary<C2, C1> dic5 = new();
    private static readonly C1 _instance = new C1("hoge", 1, "piyo");
    [GlobalSetup]
    public void Setup()
    {
        dic1[(_instance.a, _instance.b)] = _instance;
        dic2[$"{_instance.a}_{_instance.b}"] = _instance;
        dic3[Tuple.Create(_instance.a, _instance.b)] = _instance;
        dic4[new S2(_instance.a, _instance.b)] = _instance;
        dic5[new C2(_instance.a, _instance.b)] = _instance;
    }
    [Benchmark]
    public void VTuple()
    {
        dic1.TryGetValue((_instance.a, _instance.b), out var val);
    }
    [Benchmark]
    public void CombinedString()
    {
        dic2.TryGetValue($"{_instance.a}_{_instance.b}", out var val);
    }
    [Benchmark]
    public void ClassTuple()
    {
        dic3.TryGetValue(Tuple.Create(_instance.a, _instance.b), out var val);
    }
    [Benchmark]
    public void RecordStruct()
    {
        dic4.TryGetValue(new S2(_instance.a, _instance.b), out var val);
    }
    [Benchmark]
    public void RecordClass()
    {
        dic5.TryGetValue(new C2(_instance.a, _instance.b), out var val);
    }
}

zz-result.md

BenchmarkDotNet=v0.13.1, OS=Windows 10.0.19044.1706 (21H2)
Intel Core i7-9700 CPU 3.00GHz, 1 CPU, 8 logical and 8 physical cores
.NET SDK=6.0.300
  [Host]     : .NET 6.0.5 (6.0.522.21309), X64 RyuJIT
  DefaultJob : .NET 6.0.5 (6.0.522.21309), X64 RyuJIT

Method	Mean	Error	StdDev	Gen 0	Allocated
VTuple	31.19 ns	0.301 ns	0.282 ns	-	-
CombinedString	58.22 ns	0.510 ns	0.477 ns	0.0063	40 B
ClassTuple	74.28 ns	1.434 ns	1.271 ns	0.0166	104 B
RecordStruct	17.18 ns	0.069 ns	0.061 ns	-	-
RecordClass	35.05 ns	0.233 ns	0.207 ns	0.0051	32 B