C# で gRPC を使ってみた、ついでに Stream でファイル転送

message Empty {
}

message Chunk {
    bytes chunk = 1;
}

service GreetingService {
    rpc greeting(HelloRequest) returns (HelloResponse);
    rpc filesend(stream Chunk) returns (Empty);
}

namespace GreeterServer
{
    public class GreeterServiceImpl : GreetingService.GreetingServiceBase
    {
        public override Task<HelloResponse> greeting(HelloRequest request, ServerCallContext context)
        {
            return Task.FromResult(new HelloResponse { Greeting = "Hello " + request.Name });
        }

        public override async Task<Empty> filesend(IAsyncStreamReader<Chunk> stream, ServerCallContext context)
        {
            List<byte> bytes = new List<byte>();
            await stream.ForEachAsync(request =>
            {
                var temp = request.Chunk_.ToByteArray();
                bytes.AddRange(temp);
                return Task.CompletedTask;
            });

            Console.WriteLine($"size={bytes.Count}");
            // Console.WriteLine(BitConverter.ToString(bytes.ToArray()));

            // 受信完了を返す
            return new Empty();
        }
    }
}

namespace GreeterClient
{
    class Program
    {
        const string Host = "localhost";
        const int Port = 50051;

        public static void Main(string[] args)
        {
            // Create a channel
            var channel = new Channel(Host + ":" + Port, ChannelCredentials.Insecure);

            // Create a client with the channel
            var client = new GreetingService.GreetingServiceClient(channel);

            // Create a request
            var request = new HelloRequest{
                Name = "Mete - on C#",
                Age = 34,
                Sentiment = Sentiment.Happy
            };

            // Send the request
            Console.WriteLine("GreeterClient sending request");
            var response = client.greeting(request);
            Console.WriteLine("GreeterClient received response: " + response.Greeting);

            // チャンクデータの作成
            var fs = new FileStream("00013646_72B.jpg", FileMode.Open);
            byte[] data = new byte[fs.Length];
            fs.Read(data, 0, data.Length);

            // ファイルの送信処理
            var task = Task.Run(async () =>
            {
                Stopwatch sw = new Stopwatch();
                sw.Start();
                for (int i = 0; i < 100; i++)
                {
                    // 送信
                    var stream = client.filesend();
                    var chunk = Google.Protobuf.ByteString.CopyFrom(data, 0, data.Length);
                    await stream.RequestStream.WriteAsync(new Chunk() { Chunk_ = chunk });
                    await stream.RequestStream.CompleteAsync();
                    var res = await stream.ResponseAsync;
                }
                sw.Stop();
                Console.WriteLine(sw.Elapsed);
            });
            task.Wait();

            // Shutdown
            channel.ShutdownAsync().Wait();
            Console.WriteLine("Press any key to exit...");
            Console.ReadKey();
        }
    }
}