Remove deflate compression support (#480)

Author: JamesNK

src/Grpc.AspNetCore.Server/Internal/GrpcServiceOptionsSetup.cs

@@ -38,7 +38,7 @@ public void Configure(GrpcServiceOptions options)
             if (options._compressionProviders == null || options._compressionProviders.Count == 0)
             {
                 options.CompressionProviders.Add(new GzipCompressionProvider(CompressionLevel.Fastest));
-                options.CompressionProviders.Add(new DeflateCompressionProvider(CompressionLevel.Fastest));
+                // deflate is not supported. .NET's DeflateStream does not support RFC1950 - https://github.com/dotnet/corefx/issues/7570
             }
         }
     }

src/Grpc.Net.Client/Internal/GrpcProtocolConstants.cs

@@ -46,7 +46,7 @@ internal static class GrpcProtocolConstants
         internal static readonly Dictionary<string, ICompressionProvider> DefaultCompressionProviders = new Dictionary<string, ICompressionProvider>(StringComparer.Ordinal)
         {
             ["gzip"] = new GzipCompressionProvider(System.IO.Compression.CompressionLevel.Fastest),
-            ["deflate"] = new DeflateCompressionProvider(System.IO.Compression.CompressionLevel.Fastest)
+            // deflate is not supported. .NET's DeflateStream does not support RFC1950 - https://github.com/dotnet/corefx/issues/7570
         };
 
         internal static readonly string DefaultMessageAcceptEncodingValue;

src/Grpc.Net.Common/Compression/DeflateCompressionProvider.cs

@@ -33,7 +33,6 @@ public class CompressionTests : FunctionalTestBase
     {
         [TestCase("identity")]
         [TestCase("gzip")]
-        [TestCase("deflate")]
         public async Task SendCompressedMessage_ServiceCompressionConfigured_ResponseGzipEncoding(string algorithmName)
         {
             // Arrange

test/FunctionalTests/Client/CompressionTests.cs

@@ -140,15 +140,15 @@ public async Task SendCompressedMessageWithUnsupportedEncoding_ReturnUnimplement
                 if (writeContext.LoggerName == "SERVER " + typeof(GreeterService).FullName &&
                     writeContext.EventId.Name == "RpcConnectionError" &&
                     writeContext.State.ToString() == "Error status code 'Unimplemented' raised." &&
-                    GetRpcExceptionDetail(writeContext.Exception) == "Unsupported grpc-encoding value 'DOES_NOT_EXIST'. Supported encodings: identity, gzip, deflate")
+                    GetRpcExceptionDetail(writeContext.Exception) == "Unsupported grpc-encoding value 'DOES_NOT_EXIST'. Supported encodings: identity, gzip")
                 {
                     return true;
                 }
 
                 if (writeContext.LoggerName == "SERVER " + typeof(GreeterService).FullName &&
                     writeContext.EventId.Name == "ErrorReadingMessage" &&
                     writeContext.State.ToString() == "Error reading message." &&
-                    GetRpcExceptionDetail(writeContext.Exception) == "Unsupported grpc-encoding value 'DOES_NOT_EXIST'. Supported encodings: identity, gzip, deflate")
+                    GetRpcExceptionDetail(writeContext.Exception) == "Unsupported grpc-encoding value 'DOES_NOT_EXIST'. Supported encodings: identity, gzip")
                 {
                     return true;
                 }
@@ -180,9 +180,9 @@ public async Task SendCompressedMessageWithUnsupportedEncoding_ReturnUnimplement
 
             // Assert
             Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
-            Assert.AreEqual("identity,gzip,deflate", response.Headers.GetValues(GrpcProtocolConstants.MessageAcceptEncodingHeader).Single());
+            Assert.AreEqual("identity,gzip", response.Headers.GetValues(GrpcProtocolConstants.MessageAcceptEncodingHeader).Single());
 
-            response.AssertTrailerStatus(StatusCode.Unimplemented, "Unsupported grpc-encoding value 'DOES_NOT_EXIST'. Supported encodings: identity, gzip, deflate");
+            response.AssertTrailerStatus(StatusCode.Unimplemented, "Unsupported grpc-encoding value 'DOES_NOT_EXIST'. Supported encodings: identity, gzip");
         }
 
         private class DoesNotExistCompressionProvider : ICompressionProvider

test/FunctionalTests/Server/CompressionTests.cs

@@ -69,7 +69,7 @@ public async Task AsyncUnaryCall_Success_HttpRequestMessagePopulated()
             Assert.AreEqual(new Uri("https://localhost/ServiceName/MethodName"), httpRequestMessage.RequestUri);
             Assert.AreEqual(new MediaTypeHeaderValue("application/grpc"), httpRequestMessage.Content.Headers.ContentType);
             Assert.AreEqual(GrpcProtocolConstants.TEHeader, httpRequestMessage.Headers.TE.Single());
-            Assert.AreEqual("identity,gzip,deflate", httpRequestMessage.Headers.GetValues(GrpcProtocolConstants.MessageAcceptEncodingHeader).Single());
+            Assert.AreEqual("identity,gzip", httpRequestMessage.Headers.GetValues(GrpcProtocolConstants.MessageAcceptEncodingHeader).Single());
 
             var userAgent = httpRequestMessage.Headers.UserAgent.Single();
             Assert.AreEqual(GrpcProtocolConstants.UserAgentHeader, userAgent);

test/Grpc.Net.Client.Tests/AsyncUnaryCallTests.cs

@@ -143,7 +143,7 @@ public async Task AsyncUnaryCall_CompressMetadataSentWithRequest_RequestMessageC
             Assert.AreEqual("Hello world", response.Message);
 
             Debug.Assert(httpRequestMessage != null);
-            Assert.AreEqual("identity,gzip,deflate,test", httpRequestMessage.Headers.GetValues(GrpcProtocolConstants.MessageAcceptEncodingHeader).Single());
+            Assert.AreEqual("identity,gzip,test", httpRequestMessage.Headers.GetValues(GrpcProtocolConstants.MessageAcceptEncodingHeader).Single());
             Assert.AreEqual("gzip", httpRequestMessage.Headers.GetValues(GrpcProtocolConstants.MessageEncodingHeader).Single());
             Assert.AreEqual(false, httpRequestMessage.Headers.Contains(GrpcProtocolConstants.CompressionRequestAlgorithmHeader));
 
@@ -242,7 +242,7 @@ public async Task AsyncUnaryCall_CompressedResponseWithUnknownEncoding_ErrorThro
             // Assert
             var ex = await ExceptionAssert.ThrowsAsync<RpcException>(() => call.ResponseAsync).DefaultTimeout();
             Assert.AreEqual(StatusCode.Unimplemented, ex.StatusCode);
-            Assert.AreEqual("Unsupported grpc-encoding value 'not-supported'. Supported encodings: identity, gzip, deflate", ex.Status.Detail);
+            Assert.AreEqual("Unsupported grpc-encoding value 'not-supported'. Supported encodings: identity, gzip", ex.Status.Detail);
         }
 
         [Test]
@@ -322,7 +322,7 @@ await call.RequestStream.WriteAsync(new HelloRequest
             Assert.AreEqual("Hello world", response.Message);
 
             Debug.Assert(httpRequestMessage != null);
-            Assert.AreEqual("identity,gzip,deflate,test", httpRequestMessage.Headers.GetValues(GrpcProtocolConstants.MessageAcceptEncodingHeader).Single());
+            Assert.AreEqual("identity,gzip,test", httpRequestMessage.Headers.GetValues(GrpcProtocolConstants.MessageAcceptEncodingHeader).Single());
             Assert.AreEqual("gzip", httpRequestMessage.Headers.GetValues(GrpcProtocolConstants.MessageEncodingHeader).Single());
             Assert.AreEqual(false, httpRequestMessage.Headers.Contains(GrpcProtocolConstants.CompressionRequestAlgorithmHeader));