use Async I/O for SwaggerMiddleware fix #226

Author: neuecc

sandbox/Sandbox.NetCoreServer/Program.cs

@@ -1,12 +1,11 @@
-#pragma warning disable CS0219
+#pragma warning disable CS0219
 
 using Grpc.Core;
 using Grpc.Core.Logging;
 using MagicOnion;
 using MagicOnion.Client;
 using MagicOnion.HttpGateway.Swagger;
 using MagicOnion.Server;
-using MagicOnion.Server.EmbeddedServices;
 using MagicOnion.Utils;
 using MessagePack;
 using MagicOnion.Hosting;
@@ -61,15 +60,18 @@ static async Task Main(string[] args)
             // test webhost
 
             // NuGet: Microsoft.AspNetCore.Server.Kestrel
-            var webHost = new WebHostBuilder()
+            var webHost = Host.CreateDefaultBuilder()
                 .ConfigureServices(collection =>
                 {
                     // Add MagicOnionServiceDefinition for reference from Startup.
                     collection.AddSingleton<MagicOnionServiceDefinition>(magicOnionHost.Services.GetService<MagicOnionHostedServiceDefinition>().ServiceDefinition);
                 })
-                .UseKestrel()
-                .UseStartup<Startup>()
-                .UseUrls("http://localhost:5432")
+                .ConfigureWebHost(web =>
+                {
+                    web.UseKestrel()
+                    .UseStartup<Startup>()
+                    .UseUrls("http://localhost:5432");
+                })
                 .Build();
 
             await Task.WhenAll(webHost.RunAsync(), magicOnionHost.RunAsync());

src/MagicOnion.HttpGateway/MagicOnionSwaggerMiddleware.cs

@@ -1,4 +1,4 @@
-using MagicOnion.HttpGateway.Swagger;
+using MagicOnion.HttpGateway.Swagger;
 using MagicOnion.Server;
 using Microsoft.AspNetCore.Http;
 using System.Collections.Generic;
@@ -24,7 +24,7 @@ public MagicOnionSwaggerMiddleware(RequestDelegate next, IReadOnlyList<MethodHan
             this.options = options;
         }
 
-        public Task Invoke(HttpContext httpContext)
+        public async Task Invoke(HttpContext httpContext)
         {
             // reference embedded resouces
             const string prefix = "MagicOnion.HttpGateway.Swagger.SwaggerUI.";
@@ -40,8 +40,8 @@ public Task Invoke(HttpContext httpContext)
                 var bytes = builder.BuildSwaggerJson();
                 httpContext.Response.Headers["Content-Type"] = new[] { "application/json" };
                 httpContext.Response.StatusCode = 200;
-                httpContext.Response.Body.Write(bytes, 0, bytes.Length);
-                return EmptyTask;
+                await httpContext.Response.Body.WriteAsync(bytes, 0, bytes.Length);
+                return;
             }
 
             var myAssembly = typeof(MagicOnionSwaggerMiddleware).GetTypeInfo().Assembly;
@@ -53,13 +53,14 @@ public Task Invoke(HttpContext httpContext)
                     if (stream == null)
                     {
                         // not found, standard request.
-                        return next(httpContext);
+                        await next(httpContext);
+                        return;
                     }
 
                     httpContext.Response.Headers["Content-Type"] = new[] { mediaType };
                     httpContext.Response.StatusCode = 200;
                     var response = httpContext.Response.Body;
-                    stream.CopyTo(response);
+                    await stream.CopyToAsync(response);
                 }
                 else
                 {
@@ -72,26 +73,24 @@ public Task Invoke(HttpContext httpContext)
                     {
                         using (var ms = new MemoryStream())
                         {
-                            stream.CopyTo(ms);
+                            await stream.CopyToAsync(ms);
                             bytes = options.ResolveCustomResource(path, ms.ToArray());
                         }
                     }
 
                     if (bytes == null)
                     {
                         // not found, standard request.
-                        return next(httpContext);
+                        await next(httpContext);
+                        return;
                     }
 
                     httpContext.Response.Headers["Content-Type"] = new[] { mediaType };
                     httpContext.Response.StatusCode = 200;
                     var response = httpContext.Response.Body;
-                    response.Write(bytes, 0, bytes.Length);
+                    await response.WriteAsync(bytes, 0, bytes.Length);
                 }
             }
-
-
-            return EmptyTask;
         }
 
         static string GetMediaType(string path)