Initial checkin of gRPC to third_party/

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

+#region Copyright notice and license
+// Copyright 2015, 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.Threading.Tasks;
+using Grpc.Core.Internal;
+
+namespace Grpc.Core.Internal
+{
+    /// <summary>
+    /// Writes responses asynchronously to an underlying AsyncCallServer object.
+    /// </summary>
+    internal class ServerResponseStream<TRequest, TResponse> : IServerStreamWriter<TResponse>, IHasWriteOptions
+        where TRequest : class
+        where TResponse : class
+    {
+        readonly AsyncCallServer<TRequest, TResponse> call;
+        WriteOptions writeOptions;
+
+        public ServerResponseStream(AsyncCallServer<TRequest, TResponse> call)
+        {
+            this.call = call;
+        }
+
+        public Task WriteAsync(TResponse message)
+        {
+            var taskSource = new AsyncCompletionTaskSource<object>();
+            call.StartSendMessage(message, GetWriteFlags(), taskSource.CompletionDelegate);
+            return taskSource.Task;
+        }
+
+        public Task WriteStatusAsync(Status status, Metadata trailers)
+        {
+            var taskSource = new AsyncCompletionTaskSource<object>();
+            call.StartSendStatusFromServer(status, trailers, taskSource.CompletionDelegate);
+            return taskSource.Task;
+        }
+
+        public Task WriteResponseHeadersAsync(Metadata responseHeaders)
+        {
+            var taskSource = new AsyncCompletionTaskSource<object>();
+            call.StartSendInitialMetadata(responseHeaders, taskSource.CompletionDelegate);
+            return taskSource.Task;
+        }
+
+        public WriteOptions WriteOptions
+        {
+            get
+            {
+                return writeOptions;
+            }
+
+            set
+            {
+                writeOptions = value;
+            }
+        }
+
+        private WriteFlags GetWriteFlags()
+        {
+            var options = writeOptions;
+            return options != null ? options.Flags : default(WriteFlags);
+        }
+    }
+}