grpc/src/csharp/Grpc.Core/Calls.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
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#endregion

using System;
using System.Threading;
using System.Threading.Tasks;
using Grpc.Core.Internal;

namespace Grpc.Core
{
    // NOTE: this class is work-in-progress

    /// <summary>
    /// Helper methods for generated stubs to make RPC calls.
    /// </summary>
    public static class Calls
    {
        public static TResponse BlockingUnaryCall<TRequest, TResponse>(Call<TRequest, TResponse> call, TRequest req, CancellationToken token)
        {
            //TODO: implement this in real synchronous style.
            try {
                return AsyncUnaryCall(call, req, token).Result;
            } catch(AggregateException ae) {
                foreach (var e in ae.InnerExceptions)
                {
                    if (e is RpcException)
                    {
                        throw e;
                    }
                }
                throw;
            }
        }

        public static async Task<TResponse> AsyncUnaryCall<TRequest, TResponse>(Call<TRequest, TResponse> call, TRequest req, CancellationToken token)
        {
            var asyncCall = new AsyncCall<TRequest, TResponse>(call.RequestSerializer, call.ResponseDeserializer);
            asyncCall.Initialize(call.Channel, GetCompletionQueue(), call.MethodName);
            return await asyncCall.UnaryCallAsync(req);
        }

        public static void AsyncServerStreamingCall<TRequest, TResponse>(Call<TRequest, TResponse> call, TRequest req, IObserver<TResponse> outputs, CancellationToken token)
        {
            var asyncCall = new AsyncCall<TRequest, TResponse>(call.RequestSerializer, call.ResponseDeserializer);

            asyncCall.Initialize(call.Channel, GetCompletionQueue(), call.MethodName);
            asyncCall.StartServerStreamingCall(req, outputs);
        }

        public static ClientStreamingAsyncResult<TRequest, TResponse> AsyncClientStreamingCall<TRequest, TResponse>(Call<TRequest, TResponse> call, CancellationToken token)
        {
            var asyncCall = new AsyncCall<TRequest, TResponse>(call.RequestSerializer, call.ResponseDeserializer);
            asyncCall.Initialize(call.Channel, GetCompletionQueue(), call.MethodName);
            var task = asyncCall.ClientStreamingCallAsync();
            var inputs = new ClientStreamingInputObserver<TRequest, TResponse>(asyncCall);
            return new ClientStreamingAsyncResult<TRequest, TResponse>(task, inputs);
        }

        public static TResponse BlockingClientStreamingCall<TRequest, TResponse>(Call<TRequest, TResponse> call, IObservable<TRequest> inputs, CancellationToken token)
        {
            throw new NotImplementedException();
        }

        public static IObserver<TRequest> DuplexStreamingCall<TRequest, TResponse>(Call<TRequest, TResponse> call, IObserver<TResponse> outputs, CancellationToken token)
        {
            var asyncCall = new AsyncCall<TRequest, TResponse>(call.RequestSerializer, call.ResponseDeserializer);
            asyncCall.Initialize(call.Channel, GetCompletionQueue(), call.MethodName);

            asyncCall.StartDuplexStreamingCall(outputs);
            return new ClientStreamingInputObserver<TRequest, TResponse>(asyncCall);
        }

        private static CompletionQueueSafeHandle GetCompletionQueue() {
            return GrpcEnvironment.ThreadPool.CompletionQueue;
        }
    }
}