Use ReadOnlySpan<char> Improve performance after .netcoreapp2.1 (#192)

benchmark/SkyApm.Benchmark/SkyApm.Benchmark.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFrameworks>netcoreapp2.0;netcoreapp2.1</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>

benchmark/SkyApm.Benchmark/UniqueId.cs → benchmark/SkyApm.Benchmark/UniqueIdGenerate.cs

@@ -3,7 +3,7 @@ using SkyApm.Tracing;
 
 namespace SkyApm.Benchmark
 {
-    public class UniqueId
+    public class UniqueIdGenerate
     {
         private static readonly IUniqueIdGenerator Generator = new UniqueIdGenerator(new RuntimeEnvironment());
 

benchmark/SkyApm.Benchmark/UniqueIdParse.cs

+using BenchmarkDotNet.Attributes;
+using SkyApm.Tracing;
+
+namespace SkyApm.Benchmark
+{
+    public class UniqueIdParse
+    {
+        private static readonly IUniqueIdParser Parser = new UniqueIdParser();
+        private static readonly string Id = new UniqueId(long.MaxValue, long.MaxValue, long.MaxValue).ToString();
+
+        [Benchmark]
+        public void Parse() => Parser.TryParse(Id, out _);
+    }
+}

skyapm-dotnet.sln

@@ -86,10 +86,12 @@ 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}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "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
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyApm.Core.Tests", "test\SkyApm.Core.Tests\SkyApm.Core.Tests.csproj", "{5E654407-E22F-4696-A33F-C4B372F547BD}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -196,6 +198,10 @@ Global
 		{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
+		{5E654407-E22F-4696-A33F-C4B372F547BD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5E654407-E22F-4696-A33F-C4B372F547BD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5E654407-E22F-4696-A33F-C4B372F547BD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5E654407-E22F-4696-A33F-C4B372F547BD}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -234,6 +240,7 @@ Global
 		{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}
+		{5E654407-E22F-4696-A33F-C4B372F547BD} = {613F0980-91ED-4064-8E8C-168582EF4AD7}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {94C0DA2C-CCCB-4314-93A2-9809B5DD0583}

src/SkyApm.Core/SkyApm.Core.csproj

@@ -9,7 +9,8 @@
     <PackageReleaseNotes>
     </PackageReleaseNotes>
     <RootNamespace>SkyWalking</RootNamespace>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;netcoreapp2.1</TargetFrameworks>
+    <DefineConstants Condition="'$(TargetFramework)' == 'netcoreapp2.1'">$(DefineConstants);SPAN</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="AspectCore.Extensions.Reflection" Version="1.2.0" />

src/SkyApm.Core/Tracing/UniqueIdParser.cs

@@ -16,6 +16,8 @@
  *
  */
 
+using System;
+
 namespace SkyApm.Tracing
 {
     public class UniqueIdParser : IUniqueIdParser
@@ -23,14 +25,42 @@ namespace SkyApm.Tracing
         public bool TryParse(string text, out UniqueId uniqueId)
         {
             uniqueId = default(UniqueId);
-            if (text == null) return false;
+            if (string.IsNullOrEmpty(text)) return false;
+#if SPAN
+            var id = text.AsSpan();
+            var index = FindIndex(id);
+
+            if (index < 1) return false;
+            var id1 = id.Slice(0, index);
+
+            index = FindIndex(id.Slice(index + 1));
+            if (index < 1) return false;
+
+            if (!long.TryParse(id1, out var part0)) return false;
+            if (!long.TryParse(id.Slice(id1.Length + 1, index), out var part1)) return false;
+            if (!long.TryParse(id.Slice(id1.Length + index + 2), out var part2)) return false;
+#else
             var parts = text.Split("\\.".ToCharArray(), 3);
             if (parts.Length < 3) return false;
             if (!long.TryParse(parts[0], out var part0)) return false;
             if (!long.TryParse(parts[1], out var part1)) return false;
             if (!long.TryParse(parts[2], out var part2)) return false;
+#endif
             uniqueId = new UniqueId(part0, part1, part2);
             return true;
         }
+#if SPAN
+        private static int FindIndex(ReadOnlySpan<char> id)
+        {
+            var index = 0;
+            do
+            {
+                if (id[index] == '\\' || id[index] == '.')
+                    return index;
+            } while (++index < id.Length);
+
+            return -1;
+        }
+#endif
     }
 }

test/SkyApm.Core.Tests/SkyApm.Core.Tests.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFrameworks>netcoreapp2.0;netcoreapp2.1</TargetFrameworks>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.0" />
+    <PackageReference Include="xunit" Version="2.4.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0" />
+
+    <ProjectReference Include="..\..\src\SkyApm.Core\SkyApm.Core.csproj" />
+  </ItemGroup>
+
+</Project>

test/SkyApm.Core.Tests/UniqueIdParserTest.cs

+using SkyApm.Tracing;
+using System;
+using Xunit;
+
+namespace SkyApm.Core.Tests
+{
+    public class UniqueIdParserTest
+    {
+        private static readonly IUniqueIdParser Parser = new UniqueIdParser();
+
+        [Theory]
+        [InlineData(null, false)]
+        [InlineData("", false)]
+        [InlineData("1", false)]
+        [InlineData("1.1", false)]
+        [InlineData("1.1.", false)]
+        [InlineData("1.1.a", false)]
+        [InlineData("1.1.1.1", false)]
+        [InlineData("1\\1.-1", true)]
+        public void TryParse_Return(string text, bool result) =>
+            Assert.Equal(result, Parser.TryParse(text, out _));
+
+        [Theory]
+        [InlineData("1.2.3", 1, 2, 3)]
+        [InlineData("123.456.789", 123, 456, 789)]
+        [InlineData("-1.-2.-3", -1, -2, -3)]
+        [InlineData("9223372036854775807.9223372036854775807.9223372036854775807", 9223372036854775807, 9223372036854775807, 9223372036854775807)]
+        [InlineData("-9223372036854775807.-9223372036854775807.-9223372036854775807", -9223372036854775807, -9223372036854775807, -9223372036854775807)]
+        public void TryParse_Out(string text, long part1, long part2, long part3)
+        {
+            Parser.TryParse(text, out var id);
+
+            Assert.Equal(part1, id.Part1);
+            Assert.Equal(part2, id.Part2);
+            Assert.Equal(part3, id.Part3);
+        }
+    }
+}