Merge pull request #38 from LykkeCity/BufferingHelperFix

Fixed net.core 3.0 compatibility issue for MiddlewareApplicationBuild…

src/Lykke.Common.ApiLibrary/Middleware/BufferingHelper.cs

@@ -0,0 +1,50 @@
+using System;
+using System.IO;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.WebUtilities;
+
+namespace Lykke.Common.ApiLibrary.Middleware
+{
+    internal static class BufferingHelper
+    {
+        private const int DefaultBufferThreshold = 1024 * 30;
+
+        private static string _tempDirectory;
+
+        public static HttpRequest EnableRewind(this HttpRequest request)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+
+            var body = request.Body;
+            if (!body.CanSeek)
+            {
+                var fileStream = new FileBufferingReadStream(body, DefaultBufferThreshold, null, GetTempDirectory);
+                request.Body = fileStream;
+                request.HttpContext.Response.RegisterForDispose(fileStream);
+            }
+
+            return request;
+        }
+
+        private static string GetTempDirectory()
+        {
+            if (_tempDirectory != null)
+                return _tempDirectory;
+
+            // Look for folders in the following order.
+            var temp = Environment.GetEnvironmentVariable("ASPNETCORE_TEMP") // ASPNETCORE_TEMP - User set temporary location.
+                ?? Path.GetTempPath();                                       // Fall back.
+
+            if (!Directory.Exists(temp))
+            {
+                // TODO: ???
+                throw new DirectoryNotFoundException(temp);
+            }
+
+            _tempDirectory = temp;
+
+            return _tempDirectory;
+        }
+    }
+}

src/Lykke.Common.ApiLibrary/Middleware/MiddlewareApplicationBuilderExtensions.cs

@@ -3,7 +3,6 @@
 using JetBrains.Annotations;
 using Lykke.Common.Log;
 using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Http.Internal;
 using Microsoft.AspNetCore.HttpOverrides;
 using Microsoft.Extensions.DependencyInjection;
 
@@ -88,7 +87,7 @@ public static void UseLykkeMiddleware(
                 app.UseMiddleware<ClientErrorHandlerMiddleware>(logFactory);
             }
         }
-        
+
         /// <summary>
         /// Configure application to use forwarded headers
         /// </summary>
@@ -99,10 +98,10 @@ public static void UseLykkeForwardedHeaders(this IApplicationBuilder app)
             {
                 ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto | ForwardedHeaders.XForwardedHost
             };
-                
+
             forwardingOptions.KnownNetworks.Clear(); //its loopback by default
             forwardingOptions.KnownProxies.Clear();
-            
+
             app.UseForwardedHeaders(forwardingOptions);
         }
     }