from dotnet/runtimelab#2614

Author: pavelsavara

src/libraries/System.Net.Http/src/System.Net.Http.csproj

@@ -452,6 +452,22 @@
              Link="Common\System\Net\Http\HttpHandlerDefaults.cs" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'wasi'">
+    <Reference Include="System.Threading.Thread" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpHandler.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttp.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.clocks.v0_2_0.MonotonicClockInterop.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.http.v0_2_0.ITypes.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.http.v0_2_0.OutgoingHandlerInterop.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.http.v0_2_0.TypesInterop.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.io.v0_2_0.ErrorInterop.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.io.v0_2_0.IError.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.io.v0_2_0.IPoll.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.io.v0_2_0.IStreams.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.io.v0_2_0.PollInterop.cs" />
+    <Compile Include="System\Net\Http\WasiHttpHandler\WasiHttpWorld.wit.imports.wasi.io.v0_2_0.StreamsInterop.cs" />
+  </ItemGroup>
+
   <ItemGroup>
     <Reference Include="Microsoft.Win32.Primitives" />
     <Reference Include="System.Collections.NonGeneric" />
@@ -505,5 +521,4 @@
   <ItemGroup>
     <None Include="Resources\SR.resx" />
   </ItemGroup>
-
 </Project>

src/libraries/System.Net.Http/src/System/Net/Http/HttpClientHandler.cs

@@ -10,7 +10,11 @@
 using System.Threading;
 using System.Threading.Tasks;
 using System.Diagnostics.Metrics;
-#if TARGET_BROWSER
+#if TARGET_WASI
+using System.Diagnostics;
+using System.Net.Http.Metrics;
+using HttpHandlerType = System.Net.Http.WasiHttpHandler;
+#elif TARGET_BROWSER
 using System.Diagnostics;
 using System.Net.Http.Metrics;
 using HttpHandlerType = System.Net.Http.BrowserHttpHandler;
@@ -24,7 +28,7 @@ public partial class HttpClientHandler : HttpMessageHandler
     {
         private readonly HttpHandlerType _underlyingHandler;
 
-#if TARGET_BROWSER
+#if TARGET_BROWSER || TARGET_WASI
         private IMeterFactory? _meterFactory;
         private MetricsHandler? _metricsHandler;
 
@@ -90,7 +94,7 @@ protected override void Dispose(bool disposing)
         [CLSCompliant(false)]
         public IMeterFactory? MeterFactory
         {
-#if TARGET_BROWSER
+#if TARGET_BROWSER || TARGET_WASI
             get => _meterFactory;
             set
             {
@@ -258,14 +262,14 @@ public ClientCertificateOption ClientCertificateOptions
                 switch (value)
                 {
                     case ClientCertificateOption.Manual:
-#if !TARGET_BROWSER
+#if !(TARGET_BROWSER || TARGET_WASI)
                         ThrowForModifiedManagedSslOptionsIfStarted();
                         _underlyingHandler.SslOptions.LocalCertificateSelectionCallback = (sender, targetHost, localCertificates, remoteCertificate, acceptableIssuers) => CertificateHelper.GetEligibleClientCertificate(_underlyingHandler.SslOptions.ClientCertificates)!;
 #endif
                         break;
 
                     case ClientCertificateOption.Automatic:
-#if !TARGET_BROWSER
+#if !(TARGET_BROWSER || TARGET_WASI)
                         ThrowForModifiedManagedSslOptionsIfStarted();
                         _underlyingHandler.SslOptions.LocalCertificateSelectionCallback = (sender, targetHost, localCertificates, remoteCertificate, acceptableIssuers) => CertificateHelper.GetEligibleClientCertificate()!;
 #endif
@@ -296,7 +300,7 @@ public X509CertificateCollection ClientCertificates
         [UnsupportedOSPlatform("browser")]
         public Func<HttpRequestMessage, X509Certificate2?, X509Chain?, SslPolicyErrors, bool>? ServerCertificateCustomValidationCallback
         {
-#if TARGET_BROWSER
+#if TARGET_BROWSER || TARGET_WASI
             get => throw new PlatformNotSupportedException();
             set => throw new PlatformNotSupportedException();
 #else
@@ -345,7 +349,7 @@ public SslProtocols SslProtocols
         //[UnsupportedOSPlatform("tvos")]
         protected internal override HttpResponseMessage Send(HttpRequestMessage request, CancellationToken cancellationToken)
         {
-#if TARGET_BROWSER
+#if TARGET_BROWSER || TARGET_WASI
             throw new PlatformNotSupportedException();
 #else
             ArgumentNullException.ThrowIfNull(request);

src/libraries/System.Net.Http/src/System/Net/Http/WasiHttpHandler/WasiHttp.cs

@@ -0,0 +1,121 @@
+// Generated by `wit-bindgen` 0.26.0. DO NOT EDIT!
+// <auto-generated />
+#nullable enable
+using System;
+using System.Runtime.CompilerServices;
+using System.Collections;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+
+namespace WasiHttpWorld {
+
+    internal interface IWasiHttpWorld {
+    }
+
+    internal readonly struct None {}
+
+    [StructLayout(LayoutKind.Sequential)]
+    internal readonly struct Result<Ok, Err>
+    {
+        internal readonly byte Tag;
+        private readonly object value;
+
+        private Result(byte tag, object value)
+        {
+            Tag = tag;
+            this.value = value;
+        }
+
+        internal static Result<Ok, Err> ok(Ok ok)
+        {
+            return new Result<Ok, Err>(OK, ok!);
+        }
+
+        internal static Result<Ok, Err> err(Err err)
+        {
+            return new Result<Ok, Err>(ERR, err!);
+        }
+
+        internal bool IsOk => Tag == OK;
+        internal bool IsErr => Tag == ERR;
+
+        internal Ok AsOk
+        {
+            get
+            {
+                if (Tag == OK)
+                return (Ok)value;
+                else
+                throw new ArgumentException("expected OK, got " + Tag);
+            }
+        }
+
+        internal Err AsErr
+        {
+            get
+            {
+                if (Tag == ERR)
+                return (Err)value;
+                else
+                throw new ArgumentException("expected ERR, got " + Tag);
+            }
+        }
+
+        internal const byte OK = 0;
+        internal const byte ERR = 1;
+    }
+
+    internal class Option<T> {
+        private static Option<T> none = new ();
+
+        private Option()
+        {
+            HasValue = false;
+        }
+
+        internal Option(T v)
+        {
+            HasValue = true;
+            Value = v;
+        }
+
+        internal static Option<T> None => none;
+
+        [MemberNotNullWhen(true, nameof(Value))]
+        internal bool HasValue { get; }
+
+        internal T? Value { get; }
+    }
+
+    internal static class InteropString
+    {
+        internal static IntPtr FromString(string input, out int length)
+        {
+            var utf8Bytes = Encoding.UTF8.GetBytes(input);
+            length = utf8Bytes.Length;
+            var gcHandle = GCHandle.Alloc(utf8Bytes, GCHandleType.Pinned);
+            return gcHandle.AddrOfPinnedObject();
+        }
+    }
+
+    internal class WitException: Exception {
+        internal object Value { get; }
+        internal uint NestingLevel { get; }
+
+        internal WitException(object v, uint level)
+        {
+            Value = v;
+            NestingLevel = level;
+        }
+    }
+
+    namespace exports {
+        internal static class WasiHttpWorld
+        {
+        }
+    }
+
+}