Refactor SkyWalking.AspNetCore (#20)

* Refactor SkyWalking.Diagnostics module

* Init SkyWalking.Extensions.DependencyInjection project

* Add dependency package

* Refactor SkyWalking.AspNetCore

* Rename AddSkyWalkingCore to AddSkyWalking

sample/SkyWalking.Sample.Backend/Controllers/ValuesController.cs

@@ -19,9 +19,9 @@ namespace SkyWalking.Sample.Backend.Controllers
 
         // GET api/values/5
         [HttpGet("{id}")]
-        public async Task<string> Get(int id, [FromServices] IHttpClientFactory httpClientFactory)
+        public async Task<string> Get(int id)
         {
-            var httpClient = httpClientFactory.CreateClient("tracing");
+            var httpClient = new HttpClient();
             return await httpClient.GetStringAsync("http://www.baidu.com");
         }
 

skywalking-csharp.sln

@@ -38,6 +38,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Sample.Frontend"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Diagnostics.HttpClient", "src\SkyWalking.Diagnostics.HttpClient\SkyWalking.Diagnostics.HttpClient.csproj", "{49DEFCA8-4289-4875-B6A5-35D84B3D2290}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Extensions.DependencyInjection", "src\SkyWalking.Extensions.DependencyInjection\SkyWalking.Extensions.DependencyInjection.csproj", "{BF5579ED-113C-4EE6-AE03-9A9CA590C924}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -80,6 +82,10 @@ Global
 		{49DEFCA8-4289-4875-B6A5-35D84B3D2290}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{49DEFCA8-4289-4875-B6A5-35D84B3D2290}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{49DEFCA8-4289-4875-B6A5-35D84B3D2290}.Release|Any CPU.Build.0 = Release|Any CPU
+		{BF5579ED-113C-4EE6-AE03-9A9CA590C924}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{BF5579ED-113C-4EE6-AE03-9A9CA590C924}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{BF5579ED-113C-4EE6-AE03-9A9CA590C924}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{BF5579ED-113C-4EE6-AE03-9A9CA590C924}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -96,6 +102,7 @@ Global
 		{80A67B09-83F2-477F-907F-95FFF5B8FEAF} = {844CEACD-4C85-4B15-9E2B-892B01FDA4BB}
 		{2B4E350E-A1E5-4B4A-A642-BCA6D3887E5A} = {844CEACD-4C85-4B15-9E2B-892B01FDA4BB}
 		{49DEFCA8-4289-4875-B6A5-35D84B3D2290} = {79ED86A5-E9B9-49B2-9354-C911C079D03E}
+		{BF5579ED-113C-4EE6-AE03-9A9CA590C924} = {79ED86A5-E9B9-49B2-9354-C911C079D03E}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {94C0DA2C-CCCB-4314-93A2-9809B5DD0583}

src/SkyWalking.Abstractions/Diagnostics/ITracingDiagnosticListener.cs → src/SkyWalking.Abstractions/Diagnostics/ITracingDiagnosticProcessor.cs

@@ -18,7 +18,7 @@
 
 namespace SkyWalking.Diagnostics
 {
-    public interface ITracingDiagnosticListener
+    public interface ITracingDiagnosticProcessor
     {
         string ListenerName { get; }
     }

src/SkyWalking.AspNetCore/Diagnostics/AdatpeTracingDiagnosticObserver.cs

+/*
+ * Licensed to the OpenSkywalking under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+using System.Collections.Generic;
+using System.Diagnostics;
+using SkyWalking.Diagnostics;
+
+namespace SkyWalking.AspNetCore.Diagnostics
+{
+    public class AdatpeTracingDiagnosticObserver : TracingDiagnosticObserver
+    {
+        public AdatpeTracingDiagnosticObserver(IEnumerable<ITracingDiagnosticProcessor> tracingDiagnosticProcessors) 
+            : base(tracingDiagnosticProcessors)
+        {
+        }
+
+        protected override void OnNext(DiagnosticListener listener, ITracingDiagnosticProcessor diagnosticProcessor)
+        {
+            listener.SubscribeWithAdapter(diagnosticProcessor);
+        }
+    }
+}
\ No newline at end of file

src/SkyWalking.AspNetCore/Diagnostics/HostingDiagnosticListener.cs → src/SkyWalking.AspNetCore/Diagnostics/HostingDiagnosticProcessor.cs

@@ -27,12 +27,8 @@ using SkyWalking.NetworkProtocol.Trace;
 
 namespace SkyWalking.AspNetCore.Diagnostics
 {
-    public class HostingDiagnosticListener : ITracingDiagnosticListener
+    public class HostingDiagnosticProcessor : ITracingDiagnosticProcessor
     {
-        public HostingDiagnosticListener()
-        {
-        }
-
         public string ListenerName { get; } = "Microsoft.AspNetCore";
 
         [DiagnosticName("Microsoft.AspNetCore.Hosting.HttpRequestIn")]

src/SkyWalking.AspNetCore/Extensions/ServiceCollectionExtensions.cs

@@ -19,17 +19,14 @@
 using System;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.DependencyInjection.Extensions;
-using Microsoft.Extensions.Hosting;
-using Microsoft.Extensions.Http;
-using SkyWalking.AspNetCore.Diagnostics;
-using SkyWalking.Diagnostics;
+using SkyWalking.Diagnostics.HttpClient;
+using SkyWalking.Extensions.DependencyInjection;
 
 namespace SkyWalking.AspNetCore
 {
     public static class ServiceCollectionExtensions
     {
-        public static IServiceCollection AddSkyWalking(this IServiceCollection services,
+        public static SkyWalkingBuilder AddSkyWalking(this IServiceCollection services,
             Action<SkyWalkingOptions> options)
         {
             if (options == null)
@@ -37,29 +34,27 @@ namespace SkyWalking.AspNetCore
                 throw new ArgumentNullException(nameof(options));
             }
 
-            return services.AddSkyWalking().Configure(options);
+            return services.Configure(options).AddSkyWalkingCore();
         }
 
-        public static IServiceCollection AddSkyWalking(this IServiceCollection services,
+        public static SkyWalkingBuilder AddSkyWalking(this IServiceCollection services,
             IConfiguration configuration)
         {
-            return services.AddSkyWalking().Configure<SkyWalkingOptions>(configuration);
+            return services.Configure<SkyWalkingOptions>(configuration).AddSkyWalkingCore();
         }
 
-        private static IServiceCollection AddSkyWalking(this IServiceCollection services)
+        private static SkyWalkingBuilder AddSkyWalkingCore(this IServiceCollection services)
         {
             if (services == null)
             {
                 throw new ArgumentNullException(nameof(services));
             }
 
-            services.AddHttpClient<TracingHttpClient>("sw-tracing");
+            var builder = new SkyWalkingBuilder(services);
 
-            services.AddSingleton<IHostedService, SkyWalkingHostedService>();
-            services.AddSingleton<ITracingDiagnosticListener, HostingDiagnosticListener>();
-            services.AddTransient<HttpMessageHandlerBuilder, TracingHttpMessageHandlerBuilder>();
+            builder.AddHosting().AddDiagnostics().AddHttpClient();
 
-            return services;
+            return builder;
         }
     }
 }
\ No newline at end of file

src/SkyWalking.AspNetCore/Extensions/SkyWalkingBuilderExtensions.cs

+/*
+ * Licensed to the OpenSkywalking under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Http;
+using SkyWalking.AspNetCore.Diagnostics;
+using SkyWalking.Diagnostics;
+using SkyWalking.Extensions.DependencyInjection;
+
+namespace SkyWalking.AspNetCore
+{
+    internal static class SkyWalkingBuilderExtensions
+    {
+        public static SkyWalkingBuilder AddHosting(this SkyWalkingBuilder builder)
+        {   
+            builder.Services.AddSingleton<IHostedService, SkyWalkingHostedService>();
+            builder.Services.AddSingleton<ITracingDiagnosticProcessor, HostingDiagnosticProcessor>();
+            return builder;
+        }
+
+        public static SkyWalkingBuilder AddDiagnostics(this SkyWalkingBuilder builder)
+        {
+            builder.Services.AddSingleton<TracingDiagnosticObserver, AdatpeTracingDiagnosticObserver>();
+            return builder;
+        }
+
+        public static SkyWalkingBuilder AddHttpClientFactory(this SkyWalkingBuilder builder)
+        {
+            builder.Services.AddHttpClient<TracingHttpClient>();         
+            builder.Services.AddTransient<HttpMessageHandlerBuilder, TracingHttpMessageHandlerBuilder>();
+            return builder;
+        }
+    }
+}
\ No newline at end of file

src/SkyWalking.AspNetCore/SkyWalking.AspNetCore.csproj

@@ -23,5 +23,10 @@
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\SkyWalking.Core\SkyWalking.Core.csproj" />
+    <ProjectReference Include="..\SkyWalking.Diagnostics.HttpClient\SkyWalking.Diagnostics.HttpClient.csproj" />
+    <ProjectReference Include="..\SkyWalking.Extensions.DependencyInjection\SkyWalking.Extensions.DependencyInjection.csproj">
+      <Project>{BF5579ED-113C-4EE6-AE03-9A9CA590C924}</Project>
+      <Name>SkyWalking.Extensions.DependencyInjection</Name>
+    </ProjectReference>
   </ItemGroup>
 </Project>
\ No newline at end of file

src/SkyWalking.AspNetCore/SkyWalkingHostedService.cs

@@ -17,7 +17,6 @@
  */
 
 using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
@@ -32,11 +31,9 @@ namespace SkyWalking.AspNetCore
 {
     public class SkyWalkingHostedService : IHostedService
     {
-        private readonly IEnumerable<ITracingDiagnosticListener> _tracingDiagnosticListeners;
-        private readonly DiagnosticListener _diagnosticListener;
+        private readonly TracingDiagnosticObserver _diagnosticObserver;
         
-        public SkyWalkingHostedService(IOptions<SkyWalkingOptions> options, IHostingEnvironment hostingEnvironment,
-            IEnumerable<ITracingDiagnosticListener> tracingDiagnosticListeners, DiagnosticListener diagnosticListener)
+        public SkyWalkingHostedService(IOptions<SkyWalkingOptions> options, IHostingEnvironment hostingEnvironment, TracingDiagnosticObserver diagnosticObserver)
         {
             if (string.IsNullOrEmpty(options.Value.DirectServers))
             {
@@ -50,17 +47,14 @@ namespace SkyWalking.AspNetCore
 
             AgentConfig.ApplicationCode = options.Value.ApplicationCode;
             CollectorConfig.DirectServers = options.Value.DirectServers;
-
-            _tracingDiagnosticListeners = tracingDiagnosticListeners;
-            _diagnosticListener = diagnosticListener;
+            _diagnosticObserver = diagnosticObserver;
         }
 
         public async Task StartAsync(CancellationToken cancellationToken)
         {
             await GrpcChannelManager.Instance.ConnectAsync();
             await ServiceManager.Instance.Initialize();
-            foreach (var tracingDiagnosticListener in _tracingDiagnosticListeners)
-                _diagnosticListener.SubscribeWithAdapter(tracingDiagnosticListener);
+            DiagnosticListener.AllListeners.Subscribe(_diagnosticObserver);
         }
 
         public async Task StopAsync(CancellationToken cancellationToken)

src/SkyWalking.AspNetCore/TracingHttpMessageHandlerBuilder.cs

@@ -31,15 +31,7 @@ namespace SkyWalking.AspNetCore
         public override string Name
         {
             get => _name;
-            set
-            {
-                if (value == null)
-                {
-                    throw new ArgumentNullException(nameof(value));
-                }
-
-                _name = value;
-            }
+            set => _name = value ?? throw new ArgumentNullException(nameof(value));
         }
         
         public override IList<DelegatingHandler> AdditionalHandlers { get; } = new List<DelegatingHandler>();

src/SkyWalking.Core/Diagnostics/TracingDiagnosticObserver.cs

+/*
+ * Licensed to the OpenSkywalking under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using SkyWalking.Utils;
+
+namespace SkyWalking.Diagnostics
+{
+    public abstract class TracingDiagnosticObserver : IObserver<DiagnosticListener>
+    {
+        private readonly IEnumerable<ITracingDiagnosticProcessor> _tracingDiagnosticProcessors;
+
+        public TracingDiagnosticObserver(IEnumerable<ITracingDiagnosticProcessor> tracingDiagnosticProcessors)
+        {
+            _tracingDiagnosticProcessors = tracingDiagnosticProcessors ??
+                                           throw new ArgumentNullException(nameof(tracingDiagnosticProcessors));
+        }
+
+        public void OnCompleted()
+        {
+        }
+
+        public void OnError(Exception error)
+        {
+        }
+
+        public void OnNext(DiagnosticListener listener)
+        {
+            foreach (var diagnosticProcessor in _tracingDiagnosticProcessors.Distinct(x => x.ListenerName))
+            {
+                if (listener.Name == diagnosticProcessor.ListenerName)
+                {
+                    OnNext(listener, diagnosticProcessor);
+                }
+            }
+        }
+
+        protected abstract void OnNext(DiagnosticListener listener,
+            ITracingDiagnosticProcessor diagnosticProcessor);
+    }
+}
\ No newline at end of file

src/SkyWalking.Core/SkyWalking.Core.csproj

@@ -14,4 +14,7 @@
   <ItemGroup>
     <ProjectReference Include="..\SkyWalking.Abstractions\SkyWalking.Abstractions.csproj" />
   </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="4.4.1" />
+  </ItemGroup>
 </Project>
\ No newline at end of file

src/SkyWalking.Core/Utils/EnumerableExtensions.cs

+using System;
+using System.Collections.Generic;
+
+namespace SkyWalking.Utils
+{
+    internal static class EnumerableExtensions
+    {
+        public static IEnumerable<T> Distinct<T,K>(this IEnumerable<T> source, Func<T,K> predicate)
+        {
+            HashSet<K> sets = new HashSet<K>();
+            foreach (var item in source)
+            {
+                if (sets.Add(predicate(item)))
+                {
+                    yield return item;
+                }
+            }
+        }
+    }
+}
\ No newline at end of file

src/SkyWalking.Diagnostics.HttpClient/HttpClientDiagnosticListener.cs → src/SkyWalking.Diagnostics.HttpClient/HttpClientDiagnosticProcessor.cs

@@ -16,6 +16,7 @@
  *
  */
 
+using System.Diagnostics;
 using System.Net.Http;
 using Microsoft.Extensions.DiagnosticAdapter;
 using SkyWalking.Context;
@@ -25,7 +26,7 @@ using SkyWalking.NetworkProtocol.Trace;
 
 namespace SkyWalking.Diagnostics.HttpClient
 {
-    public class HttpClientDiagnosticListener : ITracingDiagnosticListener
+    public class HttpClientDiagnosticProcessor : ITracingDiagnosticProcessor
     {
         public string ListenerName { get; } = "HttpHandlerDiagnosticListener";
 

src/SkyWalking.Diagnostics.HttpClient/SkyWalking.Diagnostics.HttpClient.csproj

@@ -17,5 +17,6 @@
   <ItemGroup>
     <ProjectReference Include="..\SkyWalking.Abstractions\SkyWalking.Abstractions.csproj" />
     <ProjectReference Include="..\SkyWalking.Core\SkyWalking.Core.csproj" />
+    <ProjectReference Include="..\SkyWalking.Extensions.DependencyInjection\SkyWalking.Extensions.DependencyInjection.csproj" />
   </ItemGroup>
 </Project>
\ No newline at end of file

src/SkyWalking.Diagnostics.HttpClient/SkyWalkingBuilderExtensions.cs

+/*
+ * Licensed to the OpenSkywalking under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using SkyWalking.Extensions.DependencyInjection;
+
+namespace SkyWalking.Diagnostics.HttpClient
+{
+    public static class SkyWalkingBuilderExtensions
+    {
+        public static SkyWalkingBuilder AddHttpClient(this SkyWalkingBuilder builder)
+        {
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+
+            builder.Services.AddSingleton<ITracingDiagnosticProcessor, HttpClientDiagnosticProcessor>();
+            
+            return builder;
+        }
+    }
+}
\ No newline at end of file

src/SkyWalking.Extensions.DependencyInjection/SkyWalking.Extensions.DependencyInjection.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="..\..\build\common.props" />
+  <PropertyGroup>
+    <Description>Microsoft.Extensions.DependencyInjection (IServiceCollection) support for SkyWalking.</Description>
+    <AssemblyTitle>SkyWalking.Extensions.DependencyInjection</AssemblyTitle>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <AssemblyName>SkyWalking.Extensions.DependencyInjection</AssemblyName>
+    <PackageId>SkyWalking.Extensions.DependencyInjection</PackageId>
+    <PackageTags>SkyWalking;APM;Diagnostics</PackageTags>
+    <PackageReleaseNotes>
+    </PackageReleaseNotes>
+    <RootNamespace>SkyWalking.Extensions.DependencyInjection</RootNamespace>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\SkyWalking.Core\SkyWalking.Core.csproj" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="2.1.0-preview2-final" />
+  </ItemGroup>
+</Project>
\ No newline at end of file

src/SkyWalking.Extensions.DependencyInjection/SkyWalkingBuilder.cs

+/*
+ * Licensed to the OpenSkywalking under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+using Microsoft.Extensions.DependencyInjection;
+
+namespace SkyWalking.Extensions.DependencyInjection
+{
+    public class SkyWalkingBuilder
+    {
+        public IServiceCollection Services { get; }
+
+        public SkyWalkingBuilder(IServiceCollection services)
+        {
+            Services = services;
+        }
+    }
+}
\ No newline at end of file