HttpSys request headers Keys and Count both allocate

AspNetCore.sln

@@ -1752,6 +1752,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WebAppSample", "src\Framewo
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "test", "test", "{F43CC5EA-6032-4A11-A9B2-6D48CB5EB082}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "perf", "perf", "{74377D3E-E0C6-41A4-89ED-11A9C00142A9}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Server.HttpSys.Microbenchmarks", "src\Servers\HttpSys\perf\Microbenchmarks\Microsoft.AspNetCore.Server.HttpSys.Microbenchmarks.csproj", "{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -10513,6 +10517,38 @@ Global
 		{A8E2AB77-8F57-47C2-A961-2F316793CAFF}.Release|x64.Build.0 = Release|Any CPU
 		{A8E2AB77-8F57-47C2-A961-2F316793CAFF}.Release|x86.ActiveCfg = Release|Any CPU
 		{A8E2AB77-8F57-47C2-A961-2F316793CAFF}.Release|x86.Build.0 = Release|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Debug|arm64.ActiveCfg = Debug|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Debug|arm64.Build.0 = Debug|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Debug|x64.Build.0 = Debug|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Debug|x86.Build.0 = Debug|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Release|arm64.ActiveCfg = Release|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Release|arm64.Build.0 = Release|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Release|x64.ActiveCfg = Release|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Release|x64.Build.0 = Release|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Release|x86.ActiveCfg = Release|Any CPU
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD}.Release|x86.Build.0 = Release|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Debug|arm64.ActiveCfg = Debug|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Debug|arm64.Build.0 = Debug|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Debug|x64.Build.0 = Debug|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Debug|x86.Build.0 = Debug|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Release|Any CPU.Build.0 = Release|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Release|arm64.ActiveCfg = Release|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Release|arm64.Build.0 = Release|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Release|x64.ActiveCfg = Release|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Release|x64.Build.0 = Release|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Release|x86.ActiveCfg = Release|Any CPU
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -11378,6 +11414,9 @@ Global
 		{890B5210-48EF-488F-93A2-F13BCB07C780} = {4DA84F2B-1948-439B-85AB-E99E31331A9C}
 		{A8E2AB77-8F57-47C2-A961-2F316793CAFF} = {890B5210-48EF-488F-93A2-F13BCB07C780}
 		{F43CC5EA-6032-4A11-A9B2-6D48CB5EB082} = {4DA84F2B-1948-439B-85AB-E99E31331A9C}
+		{B6B74AC7-63AE-49E0-8283-C7B230BE12BD} = {33CAD745-5912-47D3-BAF3-5AE580FED275}
+		{74377D3E-E0C6-41A4-89ED-11A9C00142A9} = {166E48ED-9738-4E13-8618-0D805F6F0F65}
+		{3C7C65BF-0C13-418E-90BD-EC9C3CD282CB} = {74377D3E-E0C6-41A4-89ED-11A9C00142A9}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {3E8720B3-DBDD-498C-B383-2CC32A054E8F}

src/Servers/HttpSys/HttpSysServer.slnf

@@ -32,6 +32,7 @@
       "src\\Security\\Authorization\\Core\\src\\Microsoft.AspNetCore.Authorization.csproj",
       "src\\Security\\Authorization\\Policy\\src\\Microsoft.AspNetCore.Authorization.Policy.csproj",
       "src\\Servers\\Connections.Abstractions\\src\\Microsoft.AspNetCore.Connections.Abstractions.csproj",
+      "src\\Servers\\HttpSys\\perf\\Microbenchmarks\\Microsoft.AspNetCore.Server.HttpSys.Microbenchmarks.csproj",
       "src\\Servers\\HttpSys\\samples\\HotAddSample\\HotAddSample.csproj",
       "src\\Servers\\HttpSys\\samples\\QueueSharing\\QueueSharing.csproj",
       "src\\Servers\\HttpSys\\samples\\SelfHostServer\\SelfHostServer.csproj",

src/Servers/HttpSys/perf/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/Servers/HttpSys/perf/Microbenchmarks/Microsoft.AspNetCore.Server.HttpSys.Microbenchmarks.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
+    <OutputType>Exe</OutputType>
+    <ServerGarbageCollection>true</ServerGarbageCollection>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <TieredCompilation>false</TieredCompilation>
+    <DefineConstants>$(DefineConstants);IS_BENCHMARKS</DefineConstants>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Reference Include="BenchmarkDotNet" />
+    <Reference Include="Microsoft.AspNetCore.Server.HttpSys" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="$(SharedSourceRoot)BenchmarkRunner\*.cs" />
+  </ItemGroup>
+
+</Project>

src/Servers/HttpSys/perf/Microbenchmarks/README.md

@@ -0,0 +1,13 @@
+Compile the solution in Release mode (so Kestrel is available in release)
+
+```
+build.cmd /p:Configuration=Release
+```
+
+To run a specific benchmark add it as parameter
+
+```
+dotnet run -c Release --filter RequestHeaderBenchmarks*
+```
+
+Using no parameter will list all available benchmarks

src/Servers/HttpSys/perf/Microbenchmarks/RequestHeaderBenchmarks.cs

@@ -0,0 +1,130 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Buffers;
+using System.Runtime.InteropServices;
+using System.Text;
+using BenchmarkDotNet.Attributes;
+using Microsoft.AspNetCore.HttpSys.Internal;
+using RequestHeaders = Microsoft.AspNetCore.HttpSys.Internal.RequestHeaders;
+
+[SimpleJob, MemoryDiagnoser]
+public class RequestHeaderBenchmarks
+{
+    private RequestHeaders _largeRequestHeaders;
+    private RequestHeaders _smallRequestHeaders;
+
+    [GlobalSetup]
+    public unsafe void Setup()
+    {
+        _largeRequestHeaders = CreateRequestHeader(49);
+        _smallRequestHeaders = CreateRequestHeader(0);
+    }
+
+    [Benchmark]
+    public int CountSingleHeader()
+    {
+        _smallRequestHeaders.ResetFlags();
+        return _smallRequestHeaders.Count;
+    }
+
+    [Benchmark]
+    public int CountLargeHeaders()
+    {
+        _largeRequestHeaders.ResetFlags();
+        return _largeRequestHeaders.Count;
+    }
+
+    [Benchmark]
+    public ICollection<string> KeysSingleHeader()
+    {
+        _smallRequestHeaders.ResetFlags();
+        return _smallRequestHeaders.Keys;
+    }
+
+    [Benchmark]
+    public ICollection<string> KeysLargeHeaders()
+    {
+        _largeRequestHeaders.ResetFlags();
+        return _largeRequestHeaders.Keys;
+    }
+
+    private unsafe RequestHeaders CreateRequestHeader(int unknowHeaderCount)
+    {
+        var nativeContext = new NativeRequestContext(MemoryPool<byte>.Shared, null, 0, false);
+        var nativeMemory = new Span<byte>(nativeContext.NativeRequest, (int)nativeContext.Size + 8);
+
+        var requestStructure = new HttpApiTypes.HTTP_REQUEST();
+        var remainingMemory = SetUnknownHeaders(nativeMemory, ref requestStructure, GenerateUnknownHeaders(unknowHeaderCount));
+        SetHostHeader(remainingMemory, ref requestStructure);
+        MemoryMarshal.Write(nativeMemory, ref requestStructure);
+
+        var requestHeaders = new RequestHeaders(nativeContext);
+        nativeContext.ReleasePins();
+        return requestHeaders;
+    }
+
+    private unsafe Span<byte> SetHostHeader(Span<byte> nativeMemory, ref HttpApiTypes.HTTP_REQUEST requestStructure)
+    {
+        // Writing localhost to Host header
+        var dataDestination = nativeMemory.Slice(Marshal.SizeOf<HttpApiTypes.HTTP_REQUEST>());
+        int length = Encoding.ASCII.GetBytes("localhost:5001", dataDestination);
+        fixed (byte* address = &MemoryMarshal.GetReference(dataDestination))
+        {
+            requestStructure.Headers.KnownHeaders_29.pRawValue = address;
+            requestStructure.Headers.KnownHeaders_29.RawValueLength = (ushort)length;
+        }
+        return dataDestination;
+    }
+
+    /// <summary>
+    /// Writes an array HTTP_UNKNOWN_HEADER and an array of header key-value pairs to nativeMemory. Pointers in the HTTP_UNKNOWN_HEADER structure points to the corresponding key-value pair.
+    /// </summary>
+    private unsafe Span<byte> SetUnknownHeaders(Span<byte> nativeMemory, ref HttpApiTypes.HTTP_REQUEST requestStructure, IReadOnlyCollection<(string Key, string Value)> headerNames)
+    {
+        var unknownHeaderStructureDestination = nativeMemory.Slice(Marshal.SizeOf<HttpApiTypes.HTTP_REQUEST>());
+        fixed (byte* address = &MemoryMarshal.GetReference(unknownHeaderStructureDestination))
+        {
+            requestStructure.Headers.pUnknownHeaders = (HttpApiTypes.HTTP_UNKNOWN_HEADER*)address;
+        }
+        requestStructure.Headers.UnknownHeaderCount += (ushort)headerNames.Count;
+
+        var unknownHeadersSize = Marshal.SizeOf<HttpApiTypes.HTTP_UNKNOWN_HEADER>();
+        var dataDestination = unknownHeaderStructureDestination.Slice(unknownHeadersSize * headerNames.Count);
+        foreach (var headerName in headerNames)
+        {
+            var unknownHeaderStructure = new HttpApiTypes.HTTP_UNKNOWN_HEADER();
+            int nameLength = Encoding.ASCII.GetBytes(headerName.Key, dataDestination);
+            fixed (byte* address = &MemoryMarshal.GetReference(dataDestination))
+            {
+                unknownHeaderStructure.pName = address;
+                unknownHeaderStructure.NameLength = (ushort)nameLength;
+            }
+            dataDestination = dataDestination.Slice(nameLength);
+
+            if (!string.IsNullOrEmpty(headerName.Value))
+            {
+                int valueLength = Encoding.ASCII.GetBytes(headerName.Value, dataDestination);
+                fixed (byte* address = &MemoryMarshal.GetReference(dataDestination))
+                {
+                    unknownHeaderStructure.pRawValue = address;
+                    unknownHeaderStructure.RawValueLength = (ushort)valueLength;
+                }
+                dataDestination = dataDestination.Slice(nameLength);
+            }
+            MemoryMarshal.Write(unknownHeaderStructureDestination, ref unknownHeaderStructure);
+            unknownHeaderStructureDestination = unknownHeaderStructureDestination.Slice(unknownHeadersSize);
+        }
+        return dataDestination;
+    }
+
+    private IReadOnlyCollection<(string, string)> GenerateUnknownHeaders(int count)
+    {
+        var result = new List<(string, string)>();
+        for (int i = 0; i < count; i++)
+        {
+            result.Add(($"X-Custom-{i}", $"Value-{i}"));
+        }
+        return result;
+    }
+}

src/Servers/HttpSys/src/Microsoft.AspNetCore.Server.HttpSys.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <Description>ASP.NET Core HTTP server that uses the Windows HTTP Server API.</Description>
@@ -39,8 +39,10 @@
   </ItemGroup>
 
   <ItemGroup>
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Server.HttpSys.Tests" />
     <InternalsVisibleTo Include="Microsoft.AspNetCore.Server.HttpSys.FunctionalTests" />
     <InternalsVisibleTo Include="Microsoft.AspNetCore.Server.HttpSys.NonHelixTests" />
+    <InternalsVisibleTo Include="Microsoft.AspNetCore.Server.HttpSys.Microbenchmarks" />
   </ItemGroup>
 
   <ItemGroup>

src/Servers/HttpSys/test/FunctionalTests/RequestHeaderTests.cs

@@ -1,12 +1,15 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Globalization;
 using System.Net.Http;
 using System.Net.Sockets;
 using System.Text;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.HttpSys.Internal;
 using Microsoft.AspNetCore.Testing;
 using Microsoft.Extensions.Primitives;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNetCore.Server.HttpSys;
 
@@ -174,6 +177,70 @@ public async Task RequestHeaders_ClientSendTransferEncodingAndContentLength_Cont
         }
     }
 
+    [ConditionalFact]
+    public async Task RequestHeaders_AllKnownHeadersKeys_Received()
+    {
+        string customHeader = "X-KnownHeader";
+        using var server = Utilities.CreateHttpServer(out var address, httpContext =>
+        {
+            var requestHeaders = httpContext.Request.Headers;
+            Assert.Equal(3, requestHeaders.Count);
+            Assert.Equal(requestHeaders.Keys.Count, requestHeaders.Count);
+            Assert.Equal(requestHeaders.Count, requestHeaders.Values.Count);
+            Assert.Contains(customHeader, requestHeaders.Keys);
+            Assert.Contains(requestHeaders[customHeader].First(), requestHeaders.Keys);
+            Assert.Contains(HeaderNames.Host, requestHeaders.Keys);
+            return Task.FromResult(0);
+        });
+
+        foreach ((HttpSysRequestHeader Key, string Value) testRow in HeaderTestData())
+        {
+            var key = testRow.Key.ToString();
+            var headerDictionary = new Dictionary<string, string>
+            {
+                { key, testRow.Value },
+                { customHeader, key }
+            };
+            await SendRequestAsync(address, headerDictionary);
+        }
+    }
+
+    [ConditionalFact]
+    public async Task RequestHeaders_AllUnknownHeadersKeys_Received()
+    {
+        using var server = Utilities.CreateHttpServer(out var address, httpContext =>
+        {
+            var requestHeaders = httpContext.Request.Headers;
+            Assert.Equal(4, requestHeaders.Count);
+            Assert.Equal(requestHeaders.Keys.Count, requestHeaders.Count);
+            Assert.Equal(requestHeaders.Count, requestHeaders.Values.Count);
+            Assert.Contains("X-UnknownHeader-0", requestHeaders.Keys);
+            Assert.Contains("My-UnknownHeader-1", requestHeaders.Keys);
+            Assert.Contains("X-UnknownHeader-2", requestHeaders.Keys);
+            Assert.Contains(HeaderNames.Host, requestHeaders.Keys);
+            return Task.FromResult(0);
+        });
+
+        var headerDictionary = new Dictionary<string, string>
+        {
+            { "X-UnknownHeader-0", "0" },
+            { "My-UnknownHeader-1", "1" },
+            { "X-UnknownHeader-2", "2" }
+        };
+        await SendRequestAsync(address, headerDictionary);
+    }
+
+    private async Task SendRequestAsync(string uri, IReadOnlyDictionary<string, string> headers)
+    {
+        HttpClient client = new HttpClient();
+        foreach (var header in headers)
+        {
+            client.DefaultRequestHeaders.Add(header.Key, header.Value);
+        }
+        var result = await client.GetAsync(uri);
+        result.EnsureSuccessStatusCode();
+    }
+
     private async Task<string> SendRequestAsync(string uri)
     {
         using (HttpClient client = new HttpClient())
@@ -212,4 +279,47 @@ private async Task<string> SendRequestAsync(string address, IHeaderDictionary he
             return Encoding.ASCII.GetString(response, 0, read);
         }
     }
+
+    private IEnumerable<(HttpSysRequestHeader, string)> HeaderTestData()
+    {
+        // Allow, Expires, TE are response headers, hence excluded from this enumeration.
+        // Host is sent by HttpClient, hence excluded from this enumeration.
+        yield return (HttpSysRequestHeader.CacheControl, HeaderNames.CacheControl);
+        yield return (HttpSysRequestHeader.Connection, HeaderNames.Connection);
+        yield return (HttpSysRequestHeader.Date, new DateTime(2022, 11, 14).ToString("r", CultureInfo.InvariantCulture));
+        yield return (HttpSysRequestHeader.KeepAlive, HeaderNames.KeepAlive);
+        yield return (HttpSysRequestHeader.Pragma, HeaderNames.Pragma);
+        yield return (HttpSysRequestHeader.Trailer, HeaderNames.Trailer);
+        yield return (HttpSysRequestHeader.TransferEncoding, HeaderNames.TransferEncoding);
+        yield return (HttpSysRequestHeader.Upgrade, HeaderNames.Upgrade);
+        yield return (HttpSysRequestHeader.Via, "1.1 localhost");
+        yield return (HttpSysRequestHeader.Warning, """199 - "just a test" """);
+        yield return (HttpSysRequestHeader.ContentLength, "1");
+        yield return (HttpSysRequestHeader.ContentType, "application/json");
+        yield return (HttpSysRequestHeader.ContentEncoding, "utf-8");
+        yield return (HttpSysRequestHeader.ContentLanguage, "en-US");
+        yield return (HttpSysRequestHeader.ContentLocation, HeaderNames.ContentLocation);
+        yield return (HttpSysRequestHeader.ContentMd5, HeaderNames.ContentMD5);
+        yield return (HttpSysRequestHeader.ContentRange, HeaderNames.ContentRange);
+        yield return (HttpSysRequestHeader.LastModified, HeaderNames.LastModified);
+        yield return (HttpSysRequestHeader.Accept, "*/*");
+        yield return (HttpSysRequestHeader.AcceptCharset, HeaderNames.AcceptCharset);
+        yield return (HttpSysRequestHeader.AcceptEncoding, HeaderNames.AcceptEncoding);
+        yield return (HttpSysRequestHeader.AcceptLanguage, HeaderNames.AcceptLanguage);
+        yield return (HttpSysRequestHeader.Authorization, HeaderNames.Authorization);
+        yield return (HttpSysRequestHeader.Cookie, HeaderNames.Cookie);
+        yield return (HttpSysRequestHeader.Expect, HeaderNames.Expect);
+        yield return (HttpSysRequestHeader.From, HeaderNames.From);
+        yield return (HttpSysRequestHeader.IfMatch, HeaderNames.IfMatch);
+        yield return (HttpSysRequestHeader.IfModifiedSince, HeaderNames.IfModifiedSince);
+        yield return (HttpSysRequestHeader.IfNoneMatch, HeaderNames.IfNoneMatch);
+        yield return (HttpSysRequestHeader.IfRange, HeaderNames.IfRange);
+        yield return (HttpSysRequestHeader.IfUnmodifiedSince, HeaderNames.IfUnmodifiedSince);
+        yield return (HttpSysRequestHeader.MaxForwards, HeaderNames.MaxForwards);
+        yield return (HttpSysRequestHeader.ProxyAuthorization, HeaderNames.ProxyAuthorization);
+        yield return (HttpSysRequestHeader.Referer, HeaderNames.Referer);
+        yield return (HttpSysRequestHeader.Range, "bytes=0-4096");
+        yield return (HttpSysRequestHeader.Translate, HeaderNames.Translate);
+        yield return (HttpSysRequestHeader.UserAgent, HeaderNames.UserAgent);
+    }
 }