feat: support request and response compression (#27)

src/FhirPseudonymizer/CompressionMiddleware.cs

@@ -0,0 +1,42 @@
+using System;
+using System.IO.Compression;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+
+namespace FhirPseudonymizer
+{
+    public class RequestCompression
+    {
+        private readonly RequestDelegate next;
+        private const string ContentEncodingHeader = "Content-Encoding";
+        private const string ContentEncodingGzip = "gzip";
+        private const string ContentEncodingBrotli = "br";
+        private const string ContentEncodingDeflate = "deflate";
+
+        public RequestCompression(RequestDelegate next)
+        {
+            this.next = next ?? throw new ArgumentNullException(nameof(next));
+        }
+
+        public async Task Invoke(HttpContext context)
+        {
+            if (context.Request.Headers.Keys.Contains(ContentEncodingHeader))
+            {
+                switch (context.Request.Headers[ContentEncodingHeader])
+                {
+                    case ContentEncodingGzip:
+                        context.Request.Body = new GZipStream(context.Request.Body, CompressionMode.Decompress, true);
+                        break;
+                    case ContentEncodingBrotli:
+                        context.Request.Body = new BrotliStream(context.Request.Body, CompressionMode.Decompress, true);
+                        break;
+                    case ContentEncodingDeflate:
+                        context.Request.Body = new DeflateStream(context.Request.Body, CompressionMode.Decompress, true);
+                        break;
+                }
+            }
+
+            await next(context);
+        }
+    }
+}

src/FhirPseudonymizer/Startup.cs

@@ -11,6 +11,7 @@
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Diagnostics.HealthChecks;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.ResponseCompression;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Diagnostics.HealthChecks;
@@ -38,6 +39,14 @@ public Startup(IConfiguration configuration)
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
+            // services.Configure<GzipCompressionProviderOptions>(options => options.Level = CompressionLevel.Fastest);
+            services.AddResponseCompression(options =>
+            {
+                options.MimeTypes =
+                    ResponseCompressionDefaults.MimeTypes.Concat(
+                        new[] { "application/fhir+json" });
+            });
+
             var apiKey = Configuration.GetValue<string>("ApiKey");
             services.AddAuthentication(ApiKeyDefaults.AuthenticationScheme)
                 .AddApiKeyInHeaderOrQueryParams(options =>
@@ -189,6 +198,9 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 app.UseDeveloperExceptionPage();
             }
 
+            app.UseMiddleware<RequestCompression>();
+            app.UseResponseCompression();
+
             app.UseSwagger();
             app.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v2/swagger.json", "FhirPseudonymizer v2"));