Correctness: Make some private & internal classes sealed where possible

perf/benchmarkapps/Shared/BenchmarkServiceImpl.cs

@@ -20,7 +20,7 @@
 using Grpc.Core;
 using Grpc.Testing;
 
-class BenchmarkServiceImpl : BenchmarkService.BenchmarkServiceBase
+sealed class BenchmarkServiceImpl : BenchmarkService.BenchmarkServiceBase
 {
 #if CLIENT_CERTIFICATE_AUTHENTICATION
     [Microsoft.AspNetCore.Authorization.Authorize]
@@ -98,4 +98,4 @@ public static SimpleResponse CreateResponse(SimpleRequest request)
         var payload = new Payload { Body = body };
         return new SimpleResponse { Payload = payload };
     }
-}
+}

src/Grpc.AspNetCore.Server/Internal/CallHandlers/ClientStreamingServerCallHandler.cs

@@ -24,7 +24,7 @@
 
 namespace Grpc.AspNetCore.Server.Internal.CallHandlers;
 
-internal class ClientStreamingServerCallHandler<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService, TRequest, TResponse> : ServerCallHandlerBase<TService, TRequest, TResponse>
+internal sealed class ClientStreamingServerCallHandler<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService, TRequest, TResponse> : ServerCallHandlerBase<TService, TRequest, TResponse>
     where TRequest : class
     where TResponse : class
     where TService : class

src/Grpc.AspNetCore.Server/Internal/CallHandlers/DuplexStreamingServerCallHandler.cs

@@ -23,7 +23,7 @@
 
 namespace Grpc.AspNetCore.Server.Internal.CallHandlers;
 
-internal class DuplexStreamingServerCallHandler<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService, TRequest, TResponse> : ServerCallHandlerBase<TService, TRequest, TResponse>
+internal sealed class DuplexStreamingServerCallHandler<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService, TRequest, TResponse> : ServerCallHandlerBase<TService, TRequest, TResponse>
     where TRequest : class
     where TResponse : class
     where TService : class

src/Grpc.AspNetCore.Server/Internal/CallHandlers/ServerStreamingServerCallHandler.cs

@@ -23,7 +23,7 @@
 
 namespace Grpc.AspNetCore.Server.Internal.CallHandlers;
 
-internal class ServerStreamingServerCallHandler<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService, TRequest, TResponse> : ServerCallHandlerBase<TService, TRequest, TResponse>
+internal sealed class ServerStreamingServerCallHandler<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService, TRequest, TResponse> : ServerCallHandlerBase<TService, TRequest, TResponse>
     where TRequest : class
     where TResponse : class
     where TService : class

src/Grpc.AspNetCore.Server/Internal/CallHandlers/UnaryServerCallHandler.cs

@@ -24,7 +24,7 @@
 
 namespace Grpc.AspNetCore.Server.Internal.CallHandlers;
 
-internal class UnaryServerCallHandler<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService, TRequest, TResponse> : ServerCallHandlerBase<TService, TRequest, TResponse>
+internal sealed class UnaryServerCallHandler<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService, TRequest, TResponse> : ServerCallHandlerBase<TService, TRequest, TResponse>
     where TRequest : class
     where TResponse : class
     where TService : class

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

@@ -24,6 +24,6 @@ namespace Grpc.AspNetCore.Server.Internal;
 /// A marker class used to determine if all the required gRPC services were added
 /// to the <see cref="IServiceCollection"/>.
 /// </summary>
-internal class GrpcMarkerService
+internal sealed class GrpcMarkerService
 {
 }

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

@@ -20,7 +20,7 @@
 
 namespace Grpc.AspNetCore.Server.Internal;
 
-internal class GrpcServerBuilder : IGrpcServerBuilder
+internal sealed class GrpcServerBuilder : IGrpcServerBuilder
 {
     public IServiceCollection Services { get; }
 

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

@@ -22,7 +22,7 @@
 
 namespace Grpc.AspNetCore.Server.Internal;
 
-internal class GrpcServiceOptionsSetup : IConfigureOptions<GrpcServiceOptions>
+internal sealed class GrpcServiceOptionsSetup : IConfigureOptions<GrpcServiceOptions>
 {
     // Default to no send limit and 4mb receive limit.
     // Matches the gRPC C impl defaults
@@ -45,7 +45,7 @@ public void Configure(GrpcServiceOptions options)
     }
 }
 
-internal class GrpcServiceOptionsSetup<TService> : IConfigureOptions<GrpcServiceOptions<TService>> where TService : class
+internal sealed class GrpcServiceOptionsSetup<TService> : IConfigureOptions<GrpcServiceOptions<TService>> where TService : class
 {
     private readonly GrpcServiceOptions _options;
 

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

@@ -26,7 +26,7 @@ namespace Grpc.AspNetCore.Server.Internal;
 
 [DebuggerDisplay("{DebuggerToString(),nq}")]
 [DebuggerTypeProxy(typeof(HttpContextStreamReader<>.HttpContextStreamReaderDebugView))]
-internal class HttpContextStreamReader<TRequest> : IAsyncStreamReader<TRequest> where TRequest : class
+internal sealed class HttpContextStreamReader<TRequest> : IAsyncStreamReader<TRequest> where TRequest : class
 {
     private readonly HttpContextServerCallContext _serverCallContext;
     private readonly Func<DeserializationContext, TRequest> _deserializer;

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

@@ -26,7 +26,7 @@ namespace Grpc.AspNetCore.Server.Internal;
 
 [DebuggerDisplay("{DebuggerToString(),nq}")]
 [DebuggerTypeProxy(typeof(HttpContextStreamWriter<>.HttpContextStreamWriterDebugView))]
-internal class HttpContextStreamWriter<TResponse> : IServerStreamWriter<TResponse>
+internal sealed class HttpContextStreamWriter<TResponse> : IServerStreamWriter<TResponse>
     where TResponse : class
 {
     private readonly HttpContextServerCallContext _context;

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

@@ -21,7 +21,7 @@
 namespace Grpc.AspNetCore.Server.Internal;
 
 // Potentially remove in the future when https://github.com/dotnet/corefx/issues/31804 is implemented
-internal class ReadOnlySequenceStream : Stream
+internal sealed class ReadOnlySequenceStream : Stream
 {
     private static readonly Task<int> TaskOfZero = Task.FromResult(0);
 

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

@@ -31,7 +31,7 @@ namespace Grpc.AspNetCore.Server.Internal;
 /// <summary>
 /// Creates server call handlers. Provides a place to get services that call handlers will use.
 /// </summary>
-internal partial class ServerCallHandlerFactory<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService> where TService : class
+internal sealed partial class ServerCallHandlerFactory<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService> where TService : class
 {
     private readonly ILoggerFactory _loggerFactory;
     private readonly IGrpcServiceActivator<TService> _serviceActivator;

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

@@ -18,7 +18,7 @@
 
 namespace Grpc.AspNetCore.Server.Internal;
 
-internal class SystemClock : ISystemClock
+internal sealed class SystemClock : ISystemClock
 {
     public static readonly SystemClock Instance = new SystemClock();
 

src/Grpc.AspNetCore.Server/Model/Internal/BinderServiceModelProvider.cs

@@ -24,7 +24,7 @@
 
 namespace Grpc.AspNetCore.Server.Model.Internal;
 
-internal class BinderServiceMethodProvider<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService> : IServiceMethodProvider<TService> where TService : class
+internal sealed class BinderServiceMethodProvider<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService> : IServiceMethodProvider<TService> where TService : class
 {
     private readonly ILogger<BinderServiceMethodProvider<TService>> _logger;
 

src/Grpc.AspNetCore.Server/Model/Internal/MethodModel.cs

@@ -22,7 +22,7 @@
 
 namespace Grpc.AspNetCore.Server.Model.Internal;
 
-internal class MethodModel
+internal sealed class MethodModel
 {
     public MethodModel(IMethod method, RoutePattern pattern, IList<object> metadata, RequestDelegate requestDelegate)
     {

src/Grpc.AspNetCore.Server/Model/Internal/ProviderServiceBinder.cs

@@ -24,7 +24,7 @@
 
 namespace Grpc.AspNetCore.Server.Model.Internal;
 
-internal class ProviderServiceBinder<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService> : ServiceBinderBase where TService : class
+internal sealed class ProviderServiceBinder<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService> : ServiceBinderBase where TService : class
 {
     private readonly ServiceMethodProviderContext<TService> _context;
     private readonly Type _declaringType;

src/Grpc.AspNetCore.Server/Model/Internal/ServiceMethodsRegistry.cs

@@ -21,7 +21,7 @@ namespace Grpc.AspNetCore.Server.Model.Internal;
 /// <summary>
 /// A registry of all the service methods in the application.
 /// </summary>
-internal class ServiceMethodsRegistry
+internal sealed class ServiceMethodsRegistry
 {
     public List<MethodModel> Methods { get; } = new List<MethodModel>();
 }

src/Grpc.AspNetCore.Server/Model/Internal/ServiceRouteBuilder.cs

@@ -27,7 +27,7 @@
 
 namespace Grpc.AspNetCore.Server.Model.Internal;
 
-internal class ServiceRouteBuilder<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService> where TService : class
+internal sealed class ServiceRouteBuilder<[DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)] TService> where TService : class
 {
     private readonly IEnumerable<IServiceMethodProvider<TService>> _serviceMethodProviders;
     private readonly ServerCallHandlerFactory<TService> _serverCallHandlerFactory;

src/Grpc.AspNetCore.Web/Internal/Base64PipeReader.cs

@@ -25,7 +25,7 @@ namespace Grpc.AspNetCore.Web.Internal;
 /// <summary>
 /// Reads and decodes base64 encoded bytes from the inner reader.
 /// </summary>
-internal class Base64PipeReader : PipeReader
+internal sealed class Base64PipeReader : PipeReader
 {
     private readonly PipeReader _inner;
     private ReadOnlySequence<byte> _currentDecodedBuffer;

src/Grpc.AspNetCore.Web/Internal/Base64PipeWriter.cs

@@ -25,7 +25,7 @@ namespace Grpc.AspNetCore.Web.Internal;
 /// <summary>
 /// Writes bytes as base64 encoded to the inner writer.
 /// </summary>
-internal class Base64PipeWriter : PipeWriter
+internal sealed class Base64PipeWriter : PipeWriter
 {
     private readonly PipeWriter _inner;
     // We have to write original data to buffer. GetSpan/GetMemory isn't guaranteed to return the
@@ -187,4 +187,4 @@ private void WriteRemainder()
             _remainder = 0;
         }
     }
-}
+}

src/Grpc.AspNetCore.Web/Internal/GrpcWebFeature.cs

@@ -22,7 +22,7 @@
 
 namespace Grpc.AspNetCore.Web.Internal;
 
-internal class GrpcWebFeature :
+internal sealed class GrpcWebFeature :
     IRequestBodyPipeFeature,
     IHttpResponseBodyFeature,
     IHttpResponseTrailersFeature,

src/Grpc.AspNetCore.Web/Internal/MemorySegment.cs

@@ -20,7 +20,7 @@
 
 namespace Grpc.AspNetCore.Web.Internal;
 
-internal class MemorySegment<T> : ReadOnlySequenceSegment<T>
+internal sealed class MemorySegment<T> : ReadOnlySequenceSegment<T>
 {
     public MemorySegment(ReadOnlyMemory<T> memory)
     {

src/Grpc.Core.Api/CallCredentials.cs

@@ -53,7 +53,7 @@ public static CallCredentials FromInterceptor(AsyncAuthInterceptor interceptor)
     /// </summary>
     public abstract void InternalPopulateConfiguration(CallCredentialsConfiguratorBase configurator, object? state);
 
-    private class CompositeCallCredentials : CallCredentials
+    private sealed class CompositeCallCredentials : CallCredentials
     {
         readonly IReadOnlyList<CallCredentials> credentials;
 
@@ -69,7 +69,7 @@ public override void InternalPopulateConfiguration(CallCredentialsConfiguratorBa
         }
     }
 
-    private class AsyncAuthInterceptorCredentials : CallCredentials
+    private sealed class AsyncAuthInterceptorCredentials : CallCredentials
     {
         readonly AsyncAuthInterceptor interceptor;
 

src/Grpc.Core.Api/ClientBase.cs

@@ -175,12 +175,12 @@ public ClientBaseDebugType(ClientBase client)
     /// <summary>
     /// Represents configuration of ClientBase. The class itself is visible to
     /// subclasses, but contents are marked as internal to make the instances opaque.
-    /// The verbose name of this class was chosen to make name clash in generated code 
+    /// The verbose name of this class was chosen to make name clash in generated code
     /// less likely.
     /// </summary>
     protected internal class ClientBaseConfiguration
     {
-        private class ClientBaseConfigurationInterceptor : Interceptor
+        private sealed class ClientBaseConfigurationInterceptor : Interceptor
         {
             readonly Func<IMethod, string?, CallOptions, ClientBaseConfigurationInfo> interceptor;
 

src/Grpc.Core.Api/Interceptors/CallInvokerExtensions.cs

@@ -94,7 +94,7 @@ public static CallInvoker Intercept(this CallInvoker invoker, Func<Metadata, Met
         return new InterceptingCallInvoker(invoker, new MetadataInterceptor(interceptor));
     }
 
-    private class MetadataInterceptor : Interceptor
+    private sealed class MetadataInterceptor : Interceptor
     {
         readonly Func<Metadata, Metadata> interceptor;
 

src/Grpc.Core.Api/Interceptors/InterceptingCallInvoker.cs

@@ -16,7 +16,6 @@
 
 #endregion
 
-using System;
 using System.Diagnostics;
 using Grpc.Core.Utils;
 
@@ -27,7 +26,7 @@ namespace Grpc.Core.Interceptors;
 /// intercept calls through a given interceptor.
 /// </summary>
 [DebuggerDisplay("{invoker}")]
-internal class InterceptingCallInvoker : CallInvoker
+internal sealed class InterceptingCallInvoker : CallInvoker
 {
     readonly CallInvoker invoker;
     readonly Interceptor interceptor;

src/Grpc.Core.Api/Internal/UnimplementedCallInvoker.cs

@@ -17,16 +17,13 @@
 #endregion
 
 using System;
-using System.Threading.Tasks;
-using Grpc.Core;
-using Grpc.Core.Utils;
 
 namespace Grpc.Core.Internal;
 
 /// <summary>
 /// Call invoker that throws <c>NotImplementedException</c> for all requests.
 /// </summary>
-internal class UnimplementedCallInvoker : CallInvoker
+internal sealed class UnimplementedCallInvoker : CallInvoker
 {
     public UnimplementedCallInvoker()
     {

src/Grpc.Net.Client.Web/Internal/Base64RequestStream.cs

@@ -21,7 +21,7 @@
 
 namespace Grpc.Net.Client.Web.Internal;
 
-internal class Base64RequestStream : Stream
+internal sealed class Base64RequestStream : Stream
 {
     private readonly Stream _inner;
     private byte[]? _buffer;

src/Grpc.Net.Client.Web/Internal/Base64ResponseStream.cs

@@ -22,7 +22,7 @@
 
 namespace Grpc.Net.Client.Web.Internal;
 
-internal class Base64ResponseStream : Stream
+internal sealed class Base64ResponseStream : Stream
 {
     private readonly Stream _inner;
 

src/Grpc.Net.Client.Web/Internal/GrpcWebRequestContent.cs

@@ -20,7 +20,7 @@
 
 namespace Grpc.Net.Client.Web.Internal;
 
-internal class GrpcWebRequestContent : HttpContent
+internal sealed class GrpcWebRequestContent : HttpContent
 {
     private readonly HttpContent _inner;
     private readonly GrpcWebMode _mode;

src/Grpc.Net.Client.Web/Internal/GrpcWebResponseContent.cs

@@ -21,7 +21,7 @@
 
 namespace Grpc.Net.Client.Web.Internal;
 
-internal class GrpcWebResponseContent : HttpContent
+internal sealed class GrpcWebResponseContent : HttpContent
 {
     private readonly HttpContent _inner;
     private readonly GrpcWebMode _mode;

src/Grpc.Net.Client.Web/Internal/GrpcWebResponseStream.cs

@@ -29,7 +29,7 @@ namespace Grpc.Net.Client.Web.Internal;
 /// for trailers. When the trailers message is encountered then they are parsed as HTTP/1.1 trailers and
 /// added to the HttpResponseMessage.TrailingHeaders.
 /// </summary>
-internal class GrpcWebResponseStream : Stream
+internal sealed class GrpcWebResponseStream : Stream
 {
     private const int HeaderLength = 5;
 

src/Grpc.Net.Client.Web/Internal/OperatingSystem.cs

@@ -25,7 +25,7 @@ internal interface IOperatingSystem
     bool IsBrowser { get; }
 }
 
-internal class OperatingSystem : IOperatingSystem
+internal sealed class OperatingSystem : IOperatingSystem
 {
     public static readonly OperatingSystem Instance = new OperatingSystem();
 

src/Grpc.Net.Client/Balancer/Internal/BalancerAddressEqualityComparer.cs

@@ -21,7 +21,7 @@
 
 namespace Grpc.Net.Client.Balancer.Internal;
 
-internal class BalancerAddressEqualityComparer : IEqualityComparer<BalancerAddress>
+internal sealed class BalancerAddressEqualityComparer : IEqualityComparer<BalancerAddress>
 {
     internal static readonly BalancerAddressEqualityComparer Instance = new BalancerAddressEqualityComparer();
 

src/Grpc.Net.Client/Balancer/Internal/BalancerHttpHandler.cs

@@ -17,19 +17,14 @@
 #endregion
 
 #if SUPPORT_LOAD_BALANCING
-using System;
 using System.Diagnostics;
-using System.IO;
 using System.Net;
-using System.Net.Http;
-using System.Threading;
-using System.Threading.Tasks;
 using Grpc.Shared;
 using Microsoft.Extensions.Logging;
 
 namespace Grpc.Net.Client.Balancer.Internal;
 
-internal partial class BalancerHttpHandler : DelegatingHandler
+internal sealed partial class BalancerHttpHandler : DelegatingHandler
 {
     private static readonly object SetupLock = new object();
 
@@ -178,7 +173,7 @@ internal static partial class Log
         public static partial void SendingRequest(ILogger logger, Uri requestUri);
 
         [LoggerMessage(Level = LogLevel.Trace, EventId = 2, EventName = "StartingConnectCallback", Message = "Starting connect callback for {Endpoint}.")]
-        private static partial void StartingConnectCallback(ILogger logger, string endpoint); 
+        private static partial void StartingConnectCallback(ILogger logger, string endpoint);
 
         public static void StartingConnectCallback(ILogger logger, DnsEndPoint endpoint)
         {