.NET Core 2.0/DiagnosticListener changes

This attempts to use DiagnosticListener "correctly" but there is no correctly. I give up on getting the MVC version working. Entity Framework is better (except for ID constants, they aren't constants), but MVC is anonymous types and `DiagnosticAdapter` removed `netstandard` support.

I'm so done with this "API". I hope one day someone else improves it: https://github.com/dotnet/corefx/issues/18114#issuecomment-322345786

samples/Samples.AspNetCore/Controllers/TestController.cs

@@ -103,7 +103,7 @@ public IActionResult EntityFrameworkCore()
                     {
                         using (MiniProfiler.Current.Step("Insertion"))
                         {
-                            context.RouteHits.Add(new RouteHit { RouteName = name, HitCount = 1 });
+                            context.RouteHits.Add(hit = new RouteHit { RouteName = name, HitCount = 1 });
                             context.SaveChanges();
                         }
                     }

src/MiniProfiler.AspNetCore.Mvc/MiniProfiler.AspNetCore.Mvc.csproj

@@ -5,7 +5,7 @@
     <Description>Lightweight mini-profiler, designed for ASP.NET Core MVC (*not* System.Web) websites</Description>
     <Authors>Nick Craver</Authors>
     <PackageTags>ASP.NET Core;MVC;MVC Core;$(PackageBaseTags)</PackageTags>
-    <TargetFrameworks>net451;net46;netstandard1.6</TargetFrameworks>
+    <TargetFrameworks>net451;net46;netstandard1.6;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Core" Version="1.1.1" />

src/MiniProfiler.AspNetCore/DiagnosticInitializer.cs

@@ -32,11 +32,15 @@ public void Start()
 
         void IObserver<DiagnosticListener>.OnNext(DiagnosticListener value)
         {
-            foreach (var applicationInsightDiagnosticListener in _diagnosticListeners)
+            foreach (var listener in _diagnosticListeners)
             {
-                if (applicationInsightDiagnosticListener.ListenerName == value.Name)
+                if (listener.ListenerName == value.Name)
                 {
-                    _subscriptions.Add(value.SubscribeWithAdapter(applicationInsightDiagnosticListener));
+#if NETSTANDARD2_0
+                    _subscriptions.Add(value.Subscribe(listener));
+#else
+                    _subscriptions.Add(value.SubscribeWithAdapter(listener));
+#endif
                 }
             }
         }

src/MiniProfiler.AspNetCore/MiniProfiler.AspNetCore.csproj

@@ -5,14 +5,21 @@
     <Description>Lightweight mini-profiler, designed for ASP.NET Core (not System.Web) websites</Description>
     <Authors>Nick Craver</Authors>
     <PackageTags>ASP.NET Core;$(PackageBaseTags)</PackageTags>
-    <TargetFrameworks>net451;net46;netstandard1.5</TargetFrameworks>
+    <TargetFrameworks>net451;net46;netstandard1.5;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
+    <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="4.4.1" />
+    <ProjectReference Include="..\MiniProfiler.Shared\MiniProfiler.Shared.csproj" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
+    <PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" Version="2.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Html.Abstractions" Version="2.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="2.0.0" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.0'">
+    <PackageReference Include="Microsoft.Extensions.DiagnosticAdapter" Version="1.1.1" />
     <PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" Version="1.1.1" />
     <PackageReference Include="Microsoft.AspNetCore.Html.Abstractions" Version="1.1.1" />
     <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="1.1.1" />
-    <PackageReference Include="Microsoft.Extensions.DiagnosticAdapter" Version="1.1.0" />
-    <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="4.3.0" />
-    <ProjectReference Include="..\MiniProfiler.Shared\MiniProfiler.Shared.csproj" />
   </ItemGroup>
 </Project>

src/MiniProfiler.EntityFrameworkCore/MiniProfiler.EntityFrameworkCore.csproj

@@ -5,16 +5,20 @@
     <Description>MiniProfiler: Integration for Entity Framework Core</Description>
     <Authors>Nick Craver</Authors>
     <PackageTags>Entity Framework;Entity Framework Core;$(PackageBaseTags)</PackageTags>
-    <TargetFrameworks>net451;net46;netstandard1.5</TargetFrameworks>
+    <TargetFrameworks>net451;net46;netstandard1.5;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
   <PropertyGroup Label="Configuration">
     <RootNamespace>StackExchange.Profiling.Data</RootNamespace>
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\MiniProfiler.AspNetCore\MiniProfiler.AspNetCore.csproj" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="1.1.1" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="2.0.0" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="2.0.0" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.0'">
     <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="1.1.1" />
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="1.1.0" />
-    <PackageReference Include="Microsoft.Extensions.DiagnosticAdapter" Version="1.1.0" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="1.1.1" />
   </ItemGroup>
 </Project>

src/MiniProfiler.EntityFrameworkCore/RelationalDiagnosticListener.cs

@@ -1,9 +1,14 @@
 using Microsoft.EntityFrameworkCore.Storage;
-using Microsoft.Extensions.DiagnosticAdapter;
 using StackExchange.Profiling.Internal;
 using System;
 using System.Collections.Concurrent;
+#if NETSTANDARD2_0
+using Microsoft.EntityFrameworkCore.Diagnostics;
+using System.Collections.Generic;
+#else
+using Microsoft.Extensions.DiagnosticAdapter;
 using System.Data.Common;
+#endif
 
 namespace StackExchange.Profiling.Data
 {
@@ -25,9 +30,106 @@ private readonly ConcurrentDictionary<Guid, CustomTiming>
             _commands = new ConcurrentDictionary<Guid, CustomTiming>(),
             _opening = new ConcurrentDictionary<Guid, CustomTiming>(),
             _closing = new ConcurrentDictionary<Guid, CustomTiming>();
+
+#if NETSTANDARD2_0
+        // See https://github.com/aspnet/EntityFramework/issues/8007
+        private readonly ConcurrentDictionary<Guid, CustomTiming>
+            _readers = new ConcurrentDictionary<Guid, CustomTiming>();
+
+        public void OnCompleted() { }
+        public void OnError(Exception error) { }
 
-        // Until EF has a Guid on DbReader's in 2.0, we have to hackily do this
-        // Tracking here: https://github.com/aspnet/EntityFramework/issues/8007
+        public void OnNext(KeyValuePair<string, object> kv)
+        {
+            if (kv.Key == RelationalEventId.CommandExecuting.Name)
+            {
+                var data = (CommandEventData)kv.Value;
+                var timing = data.Command.GetTiming(data.ExecuteMethod + (data.IsAsync ? " (Async)" : null), MiniProfiler.Current);
+                if (timing != null)
+                {
+                    _commands[data.CommandId] = timing;
+                }
+            }
+            else if (kv.Key == RelationalEventId.CommandExecuted.Name)
+            {
+                var data = (CommandExecutedEventData)kv.Value;
+                if (_commands.TryRemove(data.CommandId, out var current))
+                {
+                    // A completion for a DataReader only means we *started* getting data back, not finished.
+                    if (data.Result is RelationalDataReader reader)
+                    {
+                        _readers[data.CommandId] = current;
+                        current.FirstFetchCompleted();
+                    }
+                    else
+                    {
+                        current.Stop();
+                    }
+                }
+            }
+            else if (kv.Key == RelationalEventId.CommandError.Name)
+            {
+                var data = (CommandErrorEventData)kv.Value;
+                if (_commands.TryRemove(data.CommandId, out var command))
+                {
+                    command.Errored = true;
+                    command.Stop();
+                }
+            }
+            else if (kv.Key == RelationalEventId.DataReaderDisposing.Name)
+            {
+                var data = (DataReaderDisposingEventData)kv.Value;
+                if (_readers.TryRemove(data.CommandId, out var reader))
+                {
+                    reader.Stop();
+                }
+            }
+            // TODO consider switching to ConnectionEndEventData.Duration
+            // This isn't as trivia as it appears due to the start offset of the request
+            else if (kv.Key == RelationalEventId.ConnectionOpening.Name)
+            {
+                var data = (ConnectionEventData)kv.Value;
+                _opening[data.ConnectionId] = MiniProfiler.Current.CustomTiming("sql",
+                    data.IsAsync ? "Connection OpenAsync()" : "Connection Open()",
+                    data.IsAsync ? "OpenAsync" : "Open");
+            }
+            else if (kv.Key == RelationalEventId.ConnectionOpened.Name)
+            {
+                var data = (ConnectionEndEventData)kv.Value;
+                if (_opening.TryRemove(data.ConnectionId, out var openingTiming))
+                {
+                    openingTiming.Stop();
+                }
+            }
+            else if (kv.Key == RelationalEventId.ConnectionClosing.Name)
+            {
+                var data = (ConnectionEventData)kv.Value;
+                _closing[data.ConnectionId] = MiniProfiler.Current.CustomTiming("sql",
+                    data.IsAsync ? "Connection CloseAsync()" : "Connection Close()",
+                    data.IsAsync ? "CloseAsync" : "Close");
+            }
+            else if (kv.Key == RelationalEventId.ConnectionClosed.Name)
+            {
+                var data = (ConnectionEndEventData)kv.Value;
+                if (_closing.TryRemove(data.ConnectionId, out var closingTiming))
+                {
+                    closingTiming.Stop();
+                }
+            }
+            else if (kv.Key == RelationalEventId.ConnectionError.Name)
+            {
+                var data = (ConnectionErrorEventData)kv.Value;
+                if (_opening.TryRemove(data.ConnectionId, out var openingTiming))
+                {
+                    openingTiming.Errored = true;
+                }
+                if (_closing.TryRemove(data.ConnectionId, out var closingTiming))
+                {
+                    closingTiming.Errored = true;
+                }
+            }
+        }
+#else
         private readonly ConcurrentDictionary<DbDataReader, CustomTiming>
             _readers = new ConcurrentDictionary<DbDataReader, CustomTiming>();
 
@@ -106,7 +208,7 @@ public void OnDataReaderDisposing(DbDataReader dataReader)
                 reader.Stop();
             }
         }
-
+        
         /// <summary>
         /// Handles ConnectionOpening events.
         /// </summary>
@@ -120,7 +222,7 @@ public void OnConnectionOpening(Guid instanceId, bool async)
                     async ? "Connection OpenAsync()" : "Connection Open()",
                     async ? "OpenAsync" : "Open");
         }
-
+        
         /// <summary>
         /// Handles ConnectionOpened events.
         /// </summary>
@@ -134,7 +236,7 @@ public void OnConnectionOpened(Guid instanceId)
                 openingTiming.Stop();
             }
         }
-
+        
         /// <summary>
         /// Handles ConnectionClosing events.
         /// </summary>
@@ -148,7 +250,7 @@ public void OnConnectionClosing(Guid instanceId, bool async)
                     async ? "Connection CloseAsync()" : "Connection Close()",
                     async ? "CloseAsync" : "Close");
         }
-
+        
         /// <summary>
         /// Handles ConnectionClosed events.
         /// </summary>
@@ -180,6 +282,7 @@ public void OnConnectionError(Guid instanceId)
                 closingTiming.Errored = true;
             }
         }
+#endif
 
         // Transactions - Not in yet
         //[DiagnosticName("Microsoft.EntityFrameworkCore.TransactionStarted")]

src/MiniProfiler.Shared/Internal/IMiniProfilerDiagnosticListener.cs

@@ -1,10 +1,18 @@
-namespace StackExchange.Profiling.Internal
+#if NETSTANDARD2_0
+using System;
+using System.Collections.Generic;
+#endif
+
+namespace StackExchange.Profiling.Internal
 {
     /// <summary>
     /// Internal MiniProfiler interface for registering DiagnosticListeners, not meant for consumption.
     /// This can and probably will break without warning. Don't use the .Internal namespace directly.
     /// </summary>
     public interface IMiniProfilerDiagnosticListener
+#if NETSTANDARD2_0
+        : IObserver<KeyValuePair<string, object>>
+#endif
     {
         /// <summary>
         /// Gets a value indicating which listener this instance should be subscribed to