perf: improve allocations in OwinEnvironment

AspNetCore.slnx

@@ -334,6 +334,7 @@
     <Project Path="src/Http/Metadata/src/Microsoft.AspNetCore.Metadata.csproj" />
   </Folder>
   <Folder Name="/src/Http/Owin/" Id="c6dae135-6509-c765-458b-3693a7b28e8c">
+    <Project Path="src/Http/Owin/benchmarks/Microsoft.AspNetCore.Owin.Microbenchmarks/Microsoft.AspNetCore.Owin.Microbenchmarks.csproj" />
     <Project Path="src/Http/Owin/src/Microsoft.AspNetCore.Owin.csproj" />
     <Project Path="src/Http/Owin/test/Microsoft.AspNetCore.Owin.Tests.csproj" />
   </Folder>
@@ -357,6 +358,7 @@
   <Folder Name="/src/Http/samples/" Id="0e46e96b-2613-2f61-4250-fc4a97d94f4c">
     <Project Path="src/Http/samples/MinimalSample/MinimalSample.csproj" />
     <Project Path="src/Http/samples/MinimalSampleFSharp/MinimalSampleFSharp.fsproj" />
+    <Project Path="src/Http/samples/MinimalSampleOwin/MinimalSampleOwin.csproj" />
     <Project Path="src/Http/samples/SampleApp/HttpAbstractions.SampleApp.csproj" />
   </Folder>
   <Folder Name="/src/Http/WebUtilities/" Id="1aadc95f-e3b5-447b-ddcf-108db21eb9ed">

src/Http/HttpAbstractions.slnf

@@ -32,22 +32,24 @@
       "src\\Http\\Http\\src\\Microsoft.AspNetCore.Http.csproj",
       "src\\Http\\Http\\test\\Microsoft.AspNetCore.Http.Tests.csproj",
       "src\\Http\\Metadata\\src\\Microsoft.AspNetCore.Metadata.csproj",
+      "src\\Http\\Owin\\benchmarks\\Microsoft.AspNetCore.Owin.Microbenchmarks\\Microsoft.AspNetCore.Owin.Microbenchmarks.csproj",
       "src\\Http\\Owin\\src\\Microsoft.AspNetCore.Owin.csproj",
       "src\\Http\\Owin\\test\\Microsoft.AspNetCore.Owin.Tests.csproj",
       "src\\Http\\Routing.Abstractions\\src\\Microsoft.AspNetCore.Routing.Abstractions.csproj",
       "src\\Http\\Routing.Abstractions\\test\\Microsoft.AspNetCore.Mvc.Routing.Abstractions.Tests.csproj",
       "src\\Http\\Routing\\perf\\Microbenchmarks\\Microsoft.AspNetCore.Routing.Microbenchmarks.csproj",
       "src\\Http\\Routing\\src\\Microsoft.AspNetCore.Routing.csproj",
       "src\\Http\\Routing\\test\\FunctionalTests\\Microsoft.AspNetCore.Routing.FunctionalTests.csproj",
+      "src\\Http\\Routing\\test\\UnitTests\\Microsoft.AspNetCore.Routing.Tests.csproj",
       "src\\Http\\Routing\\test\\testassets\\Benchmarks\\Benchmarks.csproj",
       "src\\Http\\Routing\\test\\testassets\\RoutingSandbox\\RoutingSandbox.csproj",
       "src\\Http\\Routing\\test\\testassets\\RoutingWebSite\\RoutingWebSite.csproj",
-      "src\\Http\\Routing\\test\\UnitTests\\Microsoft.AspNetCore.Routing.Tests.csproj",
-      "src\\Http\\samples\\MinimalSample\\MinimalSample.csproj",
-      "src\\Http\\samples\\SampleApp\\HttpAbstractions.SampleApp.csproj",
       "src\\Http\\WebUtilities\\perf\\Microbenchmarks\\Microsoft.AspNetCore.WebUtilities.Microbenchmarks.csproj",
       "src\\Http\\WebUtilities\\src\\Microsoft.AspNetCore.WebUtilities.csproj",
       "src\\Http\\WebUtilities\\test\\Microsoft.AspNetCore.WebUtilities.Tests.csproj",
+      "src\\Http\\samples\\MinimalSampleOwin\\MinimalSampleOwin.csproj",
+      "src\\Http\\samples\\MinimalSample\\MinimalSample.csproj",
+      "src\\Http\\samples\\SampleApp\\HttpAbstractions.SampleApp.csproj",
       "src\\Middleware\\CORS\\src\\Microsoft.AspNetCore.Cors.csproj",
       "src\\Middleware\\Diagnostics.Abstractions\\src\\Microsoft.AspNetCore.Diagnostics.Abstractions.csproj",
       "src\\Middleware\\Diagnostics\\src\\Microsoft.AspNetCore.Diagnostics.csproj",
@@ -72,4 +74,4 @@
       "src\\WebEncoders\\src\\Microsoft.Extensions.WebEncoders.csproj"
     ]
   }
-}
+}

src/Http/Owin/benchmarks/Microsoft.AspNetCore.Owin.Microbenchmarks/AssemblyInfo.cs

@@ -0,0 +1,4 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+[assembly: BenchmarkDotNet.Attributes.AspNetCoreBenchmark]

src/Http/Owin/benchmarks/Microsoft.AspNetCore.Owin.Microbenchmarks/Benchmarks/OwinEnvironmentBenchmark.cs

@@ -0,0 +1,107 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using BenchmarkDotNet.Attributes;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Microsoft.AspNetCore.Owin.Microbenchmarks.Benchmarks;
+
+[MemoryDiagnoser]
+public class OwinEnvironmentBenchmark
+{
+    const int RequestCount = 10000;
+
+    RequestDelegate _noOperationRequestDelegate;
+    RequestDelegate _accessPortsRequestDelegate;
+    RequestDelegate _accessHeadersRequestDelegate;
+
+    HttpContext _defaultHttpContext;
+    HttpContext _httpContextWithHeaders;
+
+    [GlobalSetup]
+    public void GlobalSetup()
+    {
+        _noOperationRequestDelegate = BuildRequestDelegate();
+        _accessPortsRequestDelegate = BuildRequestDelegate(beforeOwinInvokeAction: env =>
+        {
+            _ = env.TryGetValue("server.LocalPort", out var localPort);
+            _ = env.TryGetValue("server.RemotePort", out var remotePort);
+        });
+        _accessHeadersRequestDelegate = BuildRequestDelegate(
+            beforeOwinInvokeAction: env =>
+            {
+                _ = env.TryGetValue("owin.RequestHeaders", out var requestHeaders);
+            },
+            afterOwinInvokeAction: env =>
+            {
+                _ = env.TryGetValue("owin.ResponseHeaders", out var responseHeaders);
+            }
+        );
+
+        _defaultHttpContext = new DefaultHttpContext();
+
+        _httpContextWithHeaders = new DefaultHttpContext();
+        _httpContextWithHeaders.Request.Headers["CustomRequestHeader1"] = "CustomRequestValue";
+        _httpContextWithHeaders.Request.Headers["CustomRequestHeader2"] = "CustomRequestValue";
+        _httpContextWithHeaders.Response.Headers["CustomResponseHeader1"] = "CustomResponseValue";
+        _httpContextWithHeaders.Response.Headers["CustomResponseHeader2"] = "CustomResponseValue";
+    }
+
+    [Benchmark]
+    public async Task OwinRequest_NoOperation()
+    {
+        foreach (var i in Enumerable.Range(0, RequestCount))
+        {
+            await _noOperationRequestDelegate(_defaultHttpContext);
+        }
+    }
+
+    [Benchmark]
+    public async Task OwinRequest_AccessPorts()
+    {
+        foreach (var i in Enumerable.Range(0, RequestCount))
+        {
+            await _accessPortsRequestDelegate(_defaultHttpContext);
+        }
+    }
+
+    [Benchmark]
+    public async Task OwinRequest_AccessHeaders()
+    {
+        foreach (var i in Enumerable.Range(0, RequestCount))
+        {
+            await _accessHeadersRequestDelegate(_httpContextWithHeaders);
+        }
+    }
+
+    private static RequestDelegate BuildRequestDelegate(
+        Action<IDictionary<string, object>> beforeOwinInvokeAction = null,
+        Action<IDictionary<string, object>> afterOwinInvokeAction = null)
+    {
+        var serviceProvider = new ServiceCollection().BuildServiceProvider();
+        var builder = new ApplicationBuilder(serviceProvider);
+
+        return builder.UseOwin(addToPipeline =>
+        {
+            addToPipeline(next =>
+            {
+                return async env =>
+                {
+                    if (beforeOwinInvokeAction is not null)
+                    {
+                        beforeOwinInvokeAction(env);
+                    }
+
+                    await next(env);
+
+                    if (afterOwinInvokeAction is not null)
+                    {
+                        afterOwinInvokeAction(env);
+                    }
+                };
+            });
+        }).Build();
+    }
+}

src/Http/Owin/benchmarks/Microsoft.AspNetCore.Owin.Microbenchmarks/Microsoft.AspNetCore.Owin.Microbenchmarks.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Reference Include="BenchmarkDotNet" />
+    <Reference Include="Microsoft.AspNetCore.Http" />
+    <Reference Include="Microsoft.AspNetCore.Owin" />
+    <Reference Include="Microsoft.Extensions.DependencyInjection" />
+
+    <Compile Include="$(SharedSourceRoot)BenchmarkRunner\*.cs" />
+  </ItemGroup>
+
+</Project>

src/Http/Owin/src/DictionaryStringArrayWrapper.cs

@@ -10,16 +10,16 @@ namespace Microsoft.AspNetCore.Owin;
 
 internal sealed class DictionaryStringArrayWrapper : IDictionary<string, string[]>
 {
+    public readonly IHeaderDictionary Inner;
+
     public DictionaryStringArrayWrapper(IHeaderDictionary inner)
     {
         Inner = inner;
     }
 
-    public readonly IHeaderDictionary Inner;
-
-    private static KeyValuePair<string, StringValues> Convert(KeyValuePair<string, string[]> item) => new KeyValuePair<string, StringValues>(item.Key, item.Value);
+    private static KeyValuePair<string, StringValues> Convert(KeyValuePair<string, string[]> item) => new(item.Key, item.Value);
 
-    private static KeyValuePair<string, string[]> Convert(KeyValuePair<string, StringValues> item) => new KeyValuePair<string, string[]>(item.Key, item.Value);
+    private static KeyValuePair<string, string[]> Convert(KeyValuePair<string, StringValues> item) => new(item.Key, item.Value);
 
     private string[] Convert(StringValues item) => item;
 
@@ -55,9 +55,11 @@ void ICollection<KeyValuePair<string, string[]>>.CopyTo(KeyValuePair<string, str
         }
     }
 
-    IEnumerator IEnumerable.GetEnumerator() => Inner.Select(Convert).GetEnumerator();
+    public ConvertingEnumerator GetEnumerator() => new ConvertingEnumerator(Inner);
+
+    IEnumerator<KeyValuePair<string, string[]>> IEnumerable<KeyValuePair<string, string[]>>.GetEnumerator() => new ConvertingEnumerator(Inner);
 
-    IEnumerator<KeyValuePair<string, string[]>> IEnumerable<KeyValuePair<string, string[]>>.GetEnumerator() => Inner.Select(Convert).GetEnumerator();
+    IEnumerator IEnumerable.GetEnumerator() => new ConvertingEnumerator(Inner);
 
     bool ICollection<KeyValuePair<string, string[]>>.Remove(KeyValuePair<string, string[]> item) => Inner.Remove(Convert(item));
 
@@ -74,4 +76,40 @@ bool IDictionary<string, string[]>.TryGetValue(string key, out string[] value)
         value = default(StringValues);
         return false;
     }
+
+    public struct ConvertingEnumerator : IEnumerator<KeyValuePair<string, string[]>>, IEnumerator
+    {
+        private IEnumerator<KeyValuePair<string, StringValues>> _inner;
+        private KeyValuePair<string, string[]> _current;
+
+        internal ConvertingEnumerator(IDictionary<string, StringValues> inner)
+        {
+            _inner = inner.GetEnumerator();
+            _current = default;
+        }
+
+        public void Dispose()
+        {
+            _inner?.Dispose();
+            _inner = null;
+        }
+
+        public bool MoveNext()
+        {
+            if (!_inner.MoveNext())
+            {
+                _current = default;
+                return false;
+            }
+
+            _current = Convert(_inner.Current);
+            return true;
+        }
+
+        public KeyValuePair<string, string[]> Current => _current;
+
+        object IEnumerator.Current => Current;
+
+        void IEnumerator.Reset() => throw new NotSupportedException();
+    }
 }

src/Http/Owin/src/DictionaryStringValuesWrapper.cs

@@ -11,16 +11,16 @@ namespace Microsoft.AspNetCore.Owin;
 
 internal sealed class DictionaryStringValuesWrapper : IHeaderDictionary
 {
+    public readonly IDictionary<string, string[]> Inner;
+
     public DictionaryStringValuesWrapper(IDictionary<string, string[]> inner)
     {
         Inner = inner;
     }
 
-    public readonly IDictionary<string, string[]> Inner;
-
-    private static KeyValuePair<string, StringValues> Convert(KeyValuePair<string, string[]> item) => new KeyValuePair<string, StringValues>(item.Key, item.Value);
+    private static KeyValuePair<string, StringValues> Convert(KeyValuePair<string, string[]> item) => new(item.Key, item.Value);
 
-    private static KeyValuePair<string, string[]> Convert(KeyValuePair<string, StringValues> item) => new KeyValuePair<string, string[]>(item.Key, item.Value);
+    private static KeyValuePair<string, string[]> Convert(KeyValuePair<string, StringValues> item) => new(item.Key, item.Value);
 
     private StringValues Convert(string[] item) => item;
 
@@ -100,9 +100,11 @@ void ICollection<KeyValuePair<string, StringValues>>.CopyTo(KeyValuePair<string,
         }
     }
 
-    IEnumerator IEnumerable.GetEnumerator() => Inner.Select(Convert).GetEnumerator();
+    public ConvertingEnumerator GetEnumerator() => new ConvertingEnumerator(Inner);
+
+    IEnumerator<KeyValuePair<string, StringValues>> IEnumerable<KeyValuePair<string, StringValues>>.GetEnumerator() => new ConvertingEnumerator(Inner);
 
-    IEnumerator<KeyValuePair<string, StringValues>> IEnumerable<KeyValuePair<string, StringValues>>.GetEnumerator() => Inner.Select(Convert).GetEnumerator();
+    IEnumerator IEnumerable.GetEnumerator() => new ConvertingEnumerator(Inner);
 
     bool ICollection<KeyValuePair<string, StringValues>>.Remove(KeyValuePair<string, StringValues> item) => Inner.Remove(Convert(item));
 
@@ -119,4 +121,40 @@ bool IDictionary<string, StringValues>.TryGetValue(string key, out StringValues
         value = default(StringValues);
         return false;
     }
+
+    public struct ConvertingEnumerator : IEnumerator<KeyValuePair<string, StringValues>>, IEnumerator
+    {
+        private IEnumerator<KeyValuePair<string, string[]>> _inner;
+        private KeyValuePair<string, StringValues> _current;
+
+        internal ConvertingEnumerator(IDictionary<string, string[]> inner)
+        {
+            _inner = inner.GetEnumerator();
+            _current = default;
+        }
+
+        public void Dispose()
+        {
+            _inner?.Dispose();
+            _inner = null;
+        }
+
+        public bool MoveNext()
+        {
+            if (!_inner.MoveNext())
+            {
+                _current = default;
+                return false;
+            }
+
+            _current = Convert(_inner.Current);
+            return true;
+        }
+
+        public KeyValuePair<string, StringValues> Current => _current;
+
+        object IEnumerator.Current => Current;
+
+        void IEnumerator.Reset() => throw new NotSupportedException();
+    }
 }