Use JSON source generator

Author: DamianEdwards

src/BenchmarksApps/TechEmpower/Kestrel/BenchmarkApp.cs

@@ -1,11 +1,15 @@
 using System.Buffers;
+using System.Formats.Asn1;
 using System.Text;
 using System.Text.Json;
+using System.Text.Json.Serialization;
 using Microsoft.AspNetCore.Hosting.Server;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.Extensions.ObjectPool;
 
-public class BenchmarkApp : IHttpApplication<IFeatureCollection>
+namespace Kestrel;
+
+public sealed partial class BenchmarkApp : IHttpApplication<IFeatureCollection>
 {
     public IFeatureCollection CreateContext(IFeatureCollection features) => features;
 
@@ -68,16 +72,14 @@ private static async Task Plaintext(IHttpResponseFeature res, IFeatureCollection
         await body.Writer.FlushAsync();
     }
 
-    private static readonly JsonSerializerOptions _jsonSerializerOptions = new(JsonSerializerDefaults.Web);
-
     private static async Task JsonChunked(IHttpResponseFeature res, IFeatureCollection features)
     {
         res.StatusCode = StatusCodes.Status200OK;
         res.Headers.ContentType = "application/json; charset=utf-8";
 
         var body = features.GetResponseBodyFeature();
         await body.StartAsync();
-        await JsonSerializer.SerializeAsync(body.Writer, new JsonMessage { message = "Hello, World!" }, _jsonSerializerOptions);
+        await JsonSerializer.SerializeAsync(body.Writer, new JsonMessage { message = "Hello, World!" }, SerializerContext.JsonMessage);
         await body.Writer.FlushAsync();
     }
 
@@ -86,7 +88,7 @@ private static async Task JsonString(IHttpResponseFeature res, IFeatureCollectio
         res.StatusCode = StatusCodes.Status200OK;
         res.Headers.ContentType = "application/json; charset=utf-8";
 
-        var message = JsonSerializer.Serialize(new JsonMessage { message = "Hello, World!" }, _jsonSerializerOptions);
+        var message = JsonSerializer.Serialize(new JsonMessage { message = "Hello, World!" }, SerializerContext.JsonMessage);
         res.Headers.ContentLength = Encoding.UTF8.GetByteCount(message);
 
         var body = features.GetResponseBodyFeature();
@@ -104,7 +106,7 @@ private static async Task JsonUtf8Bytes(IHttpResponseFeature res, IFeatureCollec
         res.StatusCode = StatusCodes.Status200OK;
         res.Headers.ContentType = "application/json; charset=utf-8";
 
-        var messageBytes = JsonSerializer.SerializeToUtf8Bytes(new JsonMessage { message = "Hello, World!" }, _jsonSerializerOptions);
+        var messageBytes = JsonSerializer.SerializeToUtf8Bytes(new JsonMessage { message = "Hello, World!" }, SerializerContext.JsonMessage);
         res.Headers.ContentLength = messageBytes.Length;
 
         var body = features.GetResponseBodyFeature();
@@ -130,7 +132,10 @@ private static async Task Json(IHttpResponseFeature res, IFeatureCollection feat
         bufferWriter.ResetWrittenCount();
         jsonWriter.Reset(bufferWriter);
 
-        JsonSerializer.Serialize(jsonWriter, new JsonMessage { message = "Hello, World!" }, _jsonSerializerOptions);
+        JsonSerializer.Serialize(jsonWriter, new JsonMessage { message = "Hello, World!" }, SerializerContext.JsonMessage);
+
+        _jsonWriterPool.Return(jsonWriter);
+        _bufferWriterPool.Return(bufferWriter);
 
         res.Headers.ContentLength = bufferWriter.WrittenCount;
 
@@ -139,9 +144,6 @@ private static async Task Json(IHttpResponseFeature res, IFeatureCollection feat
         await body.StartAsync();
         body.Writer.Write(bufferWriter.WrittenSpan);
         await body.Writer.FlushAsync();
-
-        _jsonWriterPool.Return(jsonWriter);
-        _bufferWriterPool.Return(bufferWriter);
     }
 
     private struct JsonMessage
@@ -157,4 +159,14 @@ private class Utf8JsonWriterPooledObjectPolicy : IPooledObjectPolicy<Utf8JsonWri
 
         public bool Return(Utf8JsonWriter obj) => true;
     }
+
+    private static readonly JsonContext SerializerContext = JsonContext.Default;
+
+    [JsonSourceGenerationOptions(GenerationMode = JsonSourceGenerationMode.Serialization)]
+    [JsonSerializable(typeof(JsonMessage))]
+    private partial class JsonContext : JsonSerializerContext
+    {
+
+    }
+
 }

src/BenchmarksApps/TechEmpower/Kestrel/ConsoleLifetime.cs

@@ -1,6 +1,8 @@
 using System.Diagnostics;
 using System.Runtime.InteropServices;
 
+namespace Kestrel;
+
 public class ConsoleLifetime : IDisposable
 {
     private readonly TaskCompletionSource _tcs = new();

src/BenchmarksApps/TechEmpower/Kestrel/FeatureCollectionExtensions.cs

@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Http.Features;
+namespace Microsoft.AspNetCore.Http.Features;
 
 public static class FeatureCollectionExtensions
 {
@@ -16,9 +16,4 @@ public static IHttpResponseBodyFeature GetResponseBodyFeature(this IFeatureColle
     {
         return features.GetRequiredFeature<IHttpResponseBodyFeature>();
     }
-
-    public static TFeature GetRequiredFeature<TFeature>(this IFeatureCollection features)
-    {
-        return features.Get<TFeature>() ?? throw new InvalidOperationException($"Feature of type {typeof(TFeature).Name} not found");
-    }
 }

src/BenchmarksApps/TechEmpower/Kestrel/Program.cs

@@ -1,5 +1,7 @@
 using System.Runtime.InteropServices;
+using Kestrel;
 using Microsoft.AspNetCore.Hosting.Server.Features;
+using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets;
 using Microsoft.Extensions.Logging.Abstractions;