Improve performance: Use struct (#190)

* Improve performance: Use struct

* Add benchmark

* benchmark

* fix build error

benchmark/SkyApm.Benchmark/Program.cs

+using BenchmarkDotNet.Configs;
+using BenchmarkDotNet.Diagnosers;
+using BenchmarkDotNet.Running;
+using BenchmarkDotNet.Validators;
+
+namespace SkyApm.Benchmark
+{
+    class Program
+    {
+        public static void Main(params string[] args)
+        {
+            BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly)
+                .Run(args, ManualConfig
+                    .Create(DefaultConfig.Instance)
+                    .With(MemoryDiagnoser.Default)
+                    .With(ExecutionValidator.FailOnError));
+        }
+    }
+}

benchmark/SkyApm.Benchmark/SkyApm.Benchmark.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp2.1</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="BenchmarkDotNet" Version="0.*" />
+
+    <ProjectReference Include="..\..\src\SkyApm.Core\SkyApm.Core.csproj" />
+  </ItemGroup>
+
+</Project>

benchmark/SkyApm.Benchmark/UniqueId.cs

+using BenchmarkDotNet.Attributes;
+using SkyApm.Tracing;
+
+namespace SkyApm.Benchmark
+{
+    public class UniqueId
+    {
+        private static readonly IUniqueIdGenerator Generator = new UniqueIdGenerator(new RuntimeEnvironment());
+
+        [Benchmark]
+        public void Generate() => Generator.Generate();
+    }
+}

skyapm-dotnet.sln

@@ -86,6 +86,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SkyApm.Agent.GeneralHost",
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SkyApm.Sample.GeneralHost", "sample\SkyApm.Sample.GeneralHost\SkyApm.Sample.GeneralHost.csproj", "{477D705E-576B-46C8-8F1E-9A86EDAE9D86}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyApm.Benchmark", "benchmark\SkyApm.Benchmark\SkyApm.Benchmark.csproj", "{33581FDE-ABAF-4C27-A40A-1A2743309399}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "benchmark", "benchmark", "{2B7F59E8-147F-4399-9804-E7EAEF2DCB22}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -188,6 +192,10 @@ Global
 		{477D705E-576B-46C8-8F1E-9A86EDAE9D86}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{477D705E-576B-46C8-8F1E-9A86EDAE9D86}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{477D705E-576B-46C8-8F1E-9A86EDAE9D86}.Release|Any CPU.Build.0 = Release|Any CPU
+		{33581FDE-ABAF-4C27-A40A-1A2743309399}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{33581FDE-ABAF-4C27-A40A-1A2743309399}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{33581FDE-ABAF-4C27-A40A-1A2743309399}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{33581FDE-ABAF-4C27-A40A-1A2743309399}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -225,6 +233,7 @@ Global
 		{B43160C8-C9E3-43F6-83E9-A9A45B32F022} = {B5E677CF-2920-4B0A-A056-E73F6B2CF2BC}
 		{4C1CF0E7-4CD3-4731-9A56-E033D5216D58} = {EF6194B2-9ACB-49B9-8049-DD6AFAEB0399}
 		{477D705E-576B-46C8-8F1E-9A86EDAE9D86} = {844CEACD-4C85-4B15-9E2B-892B01FDA4BB}
+		{33581FDE-ABAF-4C27-A40A-1A2743309399} = {2B7F59E8-147F-4399-9804-E7EAEF2DCB22}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {94C0DA2C-CCCB-4314-93A2-9809B5DD0583}

src/SkyApm.Abstractions/Tracing/UniqueId.cs

-/*
+/*
  * Licensed to the SkyAPM under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
@@ -20,7 +20,7 @@ using System;
 
 namespace SkyApm.Tracing
 {
-    public class UniqueId : IEquatable<UniqueId>
+    public struct UniqueId : IEquatable<UniqueId>
     {
         public long Part1 { get; }
 
@@ -37,26 +37,25 @@ namespace SkyApm.Tracing
 
         public override string ToString() => $"{Part1}.{Part2}.{Part3}";
 
-        public bool Equals(UniqueId other)
-        {
-            if (ReferenceEquals(null, other)) return false;
-            if (ReferenceEquals(this, other)) return true;
-            if (Part1 != other.Part1) return false;
-            if (Part2 != other.Part2) return false;
-            return Part3 == other.Part3;
-        }
+        public bool Equals(UniqueId other) =>
+            Part1 == other.Part1 && Part2 == other.Part2 && Part3 == other.Part3;
 
-        public override bool Equals(object obj)
-        {
-            if (ReferenceEquals(null, obj)) return false;
-            if (ReferenceEquals(this, obj)) return true;
-            if (!(obj is UniqueId id)) return false;
-            return Equals(id);
-        }
+        public override bool Equals(object obj) =>
+            obj is UniqueId other && Equals(other);
 
         public override int GetHashCode()
         {
-            throw new NotImplementedException();
+            unchecked
+            {
+                var hashCode = Part1.GetHashCode();
+                hashCode = (hashCode * 397) ^ Part2.GetHashCode();
+                hashCode = (hashCode * 397) ^ Part3.GetHashCode();
+                return hashCode;
+            }
         }
+
+        public static bool operator ==(UniqueId left, UniqueId right) => left.Equals(right);
+
+        public static bool operator !=(UniqueId left, UniqueId right) => !left.Equals(right);
     }
-}
\ No newline at end of file
+}

src/SkyApm.Core/Tracing/UniqueIdParser.cs

-/*
+/*
  * Licensed to the SkyAPM under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
@@ -22,7 +22,7 @@ namespace SkyApm.Tracing
     {
         public bool TryParse(string text, out UniqueId uniqueId)
         {
-            uniqueId = null;
+            uniqueId = default(UniqueId);
             if (text == null) return false;
             var parts = text.Split("\\.".ToCharArray(), 3);
             if (parts.Length < 3) return false;
@@ -33,4 +33,4 @@ namespace SkyApm.Tracing
             return true;
         }
     }
-}
\ No newline at end of file
+}