Initial checkin of gRPC to third_party/

third_party/grpc/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs

Index: third_party/grpc/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs
diff --git a/third_party/grpc/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs b/third_party/grpc/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs
new file mode 100644
index 0000000000000000000000000000000000000000..ccf144de2def6e31819a88331f08c25998ad1459
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+++ b/third_party/grpc/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs
@@ -0,0 +1,317 @@
+#region Copyright notice and license
+
+// Copyright 2015-2016, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Grpc.Core.Internal;
+using Grpc.Core.Logging;
+using Grpc.Core.Utils;
+
+namespace Grpc.Core.Internal
+{
+    internal interface IServerCallHandler
+    {
+        Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment);
+    }
+
+    internal class UnaryServerCallHandler<TRequest, TResponse> : IServerCallHandler
+        where TRequest : class
+        where TResponse : class
+    {
+        static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<UnaryServerCallHandler<TRequest, TResponse>>();
+
+        readonly Method<TRequest, TResponse> method;
+        readonly UnaryServerMethod<TRequest, TResponse> handler;
+
+        public UnaryServerCallHandler(Method<TRequest, TResponse> method, UnaryServerMethod<TRequest, TResponse> handler)
+        {
+            this.method = method;
+            this.handler = handler;
+        }
+
+        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment)
+        {
+            var asyncCall = new AsyncCallServer<TRequest, TResponse>(
+                method.ResponseMarshaller.Serializer,
+                method.RequestMarshaller.Deserializer,
+                environment, newRpc.Server);
+
+            asyncCall.Initialize(newRpc.Call);
+            var finishedTask = asyncCall.ServerSideCallAsync();
+            var requestStream = new ServerRequestStream<TRequest, TResponse>(asyncCall);
+            var responseStream = new ServerResponseStream<TRequest, TResponse>(asyncCall);
+
+            Status status;
+            var context = HandlerUtils.NewContext(newRpc, asyncCall.Peer, responseStream, asyncCall.CancellationToken);
+            try
+            {
+                GrpcPreconditions.CheckArgument(await requestStream.MoveNext().ConfigureAwait(false));
+                var request = requestStream.Current;
+                // TODO(jtattermusch): we need to read the full stream so that native callhandle gets deallocated.
+                GrpcPreconditions.CheckArgument(!await requestStream.MoveNext().ConfigureAwait(false));
+                var result = await handler(request, context).ConfigureAwait(false);
+                status = context.Status;
+                await responseStream.WriteAsync(result).ConfigureAwait(false);
+            } 
+            catch (Exception e)
+            {
+                Logger.Error(e, "Exception occured in handler.");
+                status = HandlerUtils.StatusFromException(e);
+            }
+            try
+            {
+                await responseStream.WriteStatusAsync(status, context.ResponseTrailers).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException)
+            {
+                // Call has been already cancelled.
+            }
+            await finishedTask.ConfigureAwait(false);
+        }
+    }
+
+    internal class ServerStreamingServerCallHandler<TRequest, TResponse> : IServerCallHandler
+        where TRequest : class
+        where TResponse : class
+    {
+        static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<ServerStreamingServerCallHandler<TRequest, TResponse>>();
+
+        readonly Method<TRequest, TResponse> method;
+        readonly ServerStreamingServerMethod<TRequest, TResponse> handler;
+
+        public ServerStreamingServerCallHandler(Method<TRequest, TResponse> method, ServerStreamingServerMethod<TRequest, TResponse> handler)
+        {
+            this.method = method;
+            this.handler = handler;
+        }
+
+        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment)
+        {
+            var asyncCall = new AsyncCallServer<TRequest, TResponse>(
+                method.ResponseMarshaller.Serializer,
+                method.RequestMarshaller.Deserializer,
+                environment, newRpc.Server);
+
+            asyncCall.Initialize(newRpc.Call);
+            var finishedTask = asyncCall.ServerSideCallAsync();
+            var requestStream = new ServerRequestStream<TRequest, TResponse>(asyncCall);
+            var responseStream = new ServerResponseStream<TRequest, TResponse>(asyncCall);
+
+            Status status;
+            var context = HandlerUtils.NewContext(newRpc, asyncCall.Peer, responseStream, asyncCall.CancellationToken);
+            try
+            {
+                GrpcPreconditions.CheckArgument(await requestStream.MoveNext().ConfigureAwait(false));
+                var request = requestStream.Current;
+                // TODO(jtattermusch): we need to read the full stream so that native callhandle gets deallocated.
+                GrpcPreconditions.CheckArgument(!await requestStream.MoveNext().ConfigureAwait(false));
+                await handler(request, responseStream, context).ConfigureAwait(false);
+                status = context.Status;
+            }
+            catch (Exception e)
+            {
+                Logger.Error(e, "Exception occured in handler.");
+                status = HandlerUtils.StatusFromException(e);
+            }
+
+            try
+            {
+                await responseStream.WriteStatusAsync(status, context.ResponseTrailers).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException)
+            {
+                // Call has been already cancelled.
+            }
+            await finishedTask.ConfigureAwait(false);
+        }
+    }
+
+    internal class ClientStreamingServerCallHandler<TRequest, TResponse> : IServerCallHandler
+        where TRequest : class
+        where TResponse : class
+    {
+        static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<ClientStreamingServerCallHandler<TRequest, TResponse>>();
+
+        readonly Method<TRequest, TResponse> method;
+        readonly ClientStreamingServerMethod<TRequest, TResponse> handler;
+
+        public ClientStreamingServerCallHandler(Method<TRequest, TResponse> method, ClientStreamingServerMethod<TRequest, TResponse> handler)
+        {
+            this.method = method;
+            this.handler = handler;
+        }
+
+        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment)
+        {
+            var asyncCall = new AsyncCallServer<TRequest, TResponse>(
+                method.ResponseMarshaller.Serializer,
+                method.RequestMarshaller.Deserializer,
+                environment, newRpc.Server);
+
+            asyncCall.Initialize(newRpc.Call);
+            var finishedTask = asyncCall.ServerSideCallAsync();
+            var requestStream = new ServerRequestStream<TRequest, TResponse>(asyncCall);
+            var responseStream = new ServerResponseStream<TRequest, TResponse>(asyncCall);
+
+            Status status;
+            var context = HandlerUtils.NewContext(newRpc, asyncCall.Peer, responseStream, asyncCall.CancellationToken);
+            try
+            {
+                var result = await handler(requestStream, context).ConfigureAwait(false);
+                status = context.Status;
+                try
+                {
+                    await responseStream.WriteAsync(result).ConfigureAwait(false);
+                }
+                catch (OperationCanceledException)
+                {
+                    status = Status.DefaultCancelled;
+                }
+            }
+            catch (Exception e)
+            {
+                Logger.Error(e, "Exception occured in handler.");
+                status = HandlerUtils.StatusFromException(e);
+            }
+
+            try
+            {
+                await responseStream.WriteStatusAsync(status, context.ResponseTrailers).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException)
+            {
+                // Call has been already cancelled.
+            }
+            await finishedTask.ConfigureAwait(false);
+        }
+    }
+
+    internal class DuplexStreamingServerCallHandler<TRequest, TResponse> : IServerCallHandler
+        where TRequest : class
+        where TResponse : class
+    {
+        static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<DuplexStreamingServerCallHandler<TRequest, TResponse>>();
+
+        readonly Method<TRequest, TResponse> method;
+        readonly DuplexStreamingServerMethod<TRequest, TResponse> handler;
+
+        public DuplexStreamingServerCallHandler(Method<TRequest, TResponse> method, DuplexStreamingServerMethod<TRequest, TResponse> handler)
+        {
+            this.method = method;
+            this.handler = handler;
+        }
+
+        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment)
+        {
+            var asyncCall = new AsyncCallServer<TRequest, TResponse>(
+                method.ResponseMarshaller.Serializer,
+                method.RequestMarshaller.Deserializer,
+                environment, newRpc.Server);
+
+            asyncCall.Initialize(newRpc.Call);
+            var finishedTask = asyncCall.ServerSideCallAsync();
+            var requestStream = new ServerRequestStream<TRequest, TResponse>(asyncCall);
+            var responseStream = new ServerResponseStream<TRequest, TResponse>(asyncCall);
+
+            Status status;
+            var context = HandlerUtils.NewContext(newRpc, asyncCall.Peer, responseStream, asyncCall.CancellationToken);
+            try
+            {
+                await handler(requestStream, responseStream, context).ConfigureAwait(false);
+                status = context.Status;
+            }
+            catch (Exception e)
+            {
+                Logger.Error(e, "Exception occured in handler.");
+                status = HandlerUtils.StatusFromException(e);
+            }
+            try
+            {
+                await responseStream.WriteStatusAsync(status, context.ResponseTrailers).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException)
+            {
+                // Call has been already cancelled.
+            }
+            await finishedTask.ConfigureAwait(false);
+        }
+    }
+
+    internal class NoSuchMethodCallHandler : IServerCallHandler
+    {
+        public static readonly NoSuchMethodCallHandler Instance = new NoSuchMethodCallHandler();
+
+        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment)
+        {
+            // We don't care about the payload type here.
+            var asyncCall = new AsyncCallServer<byte[], byte[]>(
+                (payload) => payload, (payload) => payload, environment, newRpc.Server);
+            
+            asyncCall.Initialize(newRpc.Call);
+            var finishedTask = asyncCall.ServerSideCallAsync();
+            var responseStream = new ServerResponseStream<byte[], byte[]>(asyncCall);
+
+            await responseStream.WriteStatusAsync(new Status(StatusCode.Unimplemented, ""), Metadata.Empty).ConfigureAwait(false);
+            await finishedTask.ConfigureAwait(false);
+        }
+    }
+
+    internal static class HandlerUtils
+    {
+        public static Status StatusFromException(Exception e)
+        {
+            var rpcException = e as RpcException;
+            if (rpcException != null)
+            {
+                // use the status thrown by handler.
+                return rpcException.Status;
+            }
+
+            // TODO(jtattermusch): what is the right status code here?
+            return new Status(StatusCode.Unknown, "Exception was thrown by handler.");
+        }
+
+        public static ServerCallContext NewContext<TRequest, TResponse>(ServerRpcNew newRpc, string peer, ServerResponseStream<TRequest, TResponse> serverResponseStream, CancellationToken cancellationToken)
+            where TRequest : class
+            where TResponse : class
+        {
+            DateTime realtimeDeadline = newRpc.Deadline.ToClockType(GPRClockType.Realtime).ToDateTime();
+
+            return new ServerCallContext(newRpc.Call, newRpc.Method, newRpc.Host, peer, realtimeDeadline,
+                newRpc.RequestMetadata, cancellationToken, serverResponseStream.WriteResponseHeadersAsync, serverResponseStream);
+        }
+    }
+}