feat: create bidirectional stream & renaming server stream

src/Ydb.Sdk/src/Client/Response.cs

@@ -63,11 +63,11 @@ public abstract class StreamResponse<TProtoResponse, TResponse>
     where TProtoResponse : class
     where TResponse : class
 {
-    private readonly Driver.StreamIterator<TProtoResponse> _iterator;
+    private readonly Driver.ServerStream<TProtoResponse> _iterator;
     private TResponse? _response;
     private bool _transportError;
 
-    internal StreamResponse(Driver.StreamIterator<TProtoResponse> iterator)
+    internal StreamResponse(Driver.ServerStream<TProtoResponse> iterator)
     {
         _iterator = iterator;
     }

src/Ydb.Sdk/src/Driver.cs

@@ -150,7 +150,7 @@ internal async Task<TResponse> UnaryCall<TRequest, TResponse>(
         }
     }
 
-    internal StreamIterator<TResponse> StreamCall<TRequest, TResponse>(
+    internal ServerStream<TResponse> ServerStreamCall<TRequest, TResponse>(
         Method<TRequest, TResponse> method,
         TRequest request,
         GrpcRequestSettings settings)
@@ -160,22 +160,30 @@ internal StreamIterator<TResponse> StreamCall<TRequest, TResponse>(
         var (endpoint, channel) = GetChannel(settings.NodeId);
         var callInvoker = channel.CreateCallInvoker();
 
-        try
-        {
-            var call = callInvoker.AsyncServerStreamingCall(
-                method: method,
-                host: null,
-                options: GetCallOptions(settings, true),
-                request: request);
+        var call = callInvoker.AsyncServerStreamingCall(
+            method: method,
+            host: null,
+            options: GetCallOptions(settings, true),
+            request: request);
 
-            return new StreamIterator<TResponse>(call, () => { PessimizeEndpoint(endpoint); });
-        }
-        catch (RpcException e)
-        {
-            PessimizeEndpoint(endpoint);
+        return new ServerStream<TResponse>(call, () => { PessimizeEndpoint(endpoint); });
+    }
 
-            throw new TransportException(e);
-        }
+    internal BidirectionalStream<TRequest, TResponse> BidirectionalStreamCall<TRequest, TResponse>(
+        Method<TRequest, TResponse> method,
+        GrpcRequestSettings settings)
+        where TRequest : class
+        where TResponse : class
+    {
+        var (endpoint, channel) = GetChannel(settings.NodeId);
+        var callInvoker = channel.CreateCallInvoker();
+
+        var call = callInvoker.AsyncDuplexStreamingCall(
+            method: method,
+            host: null,
+            options: GetCallOptions(settings, true));
+
+        return new BidirectionalStream<TRequest, TResponse>(call, () => { PessimizeEndpoint(endpoint); });
     }
 
     private (string, GrpcChannel) GetChannel(long nodeId)
@@ -319,12 +327,12 @@ private CallOptions GetCallOptions(GrpcRequestSettings settings, bool streaming)
         return options;
     }
 
-    internal sealed class StreamIterator<TResponse> : IAsyncEnumerator<TResponse>, IAsyncEnumerable<TResponse>
+    internal sealed class ServerStream<TResponse> : IAsyncEnumerator<TResponse>, IAsyncEnumerable<TResponse>
     {
         private readonly AsyncServerStreamingCall<TResponse> _responseStream;
         private readonly Action _rpcErrorAction;
 
-        internal StreamIterator(AsyncServerStreamingCall<TResponse> responseStream, Action rpcErrorAction)
+        internal ServerStream(AsyncServerStreamingCall<TResponse> responseStream, Action rpcErrorAction)
         {
             _responseStream = responseStream;
             _rpcErrorAction = rpcErrorAction;
@@ -359,6 +367,62 @@ public async ValueTask<bool> MoveNextAsync()
         }
     }
 
+    internal sealed class BidirectionalStream<TRequest, TResponse> : IAsyncEnumerator<TResponse>,
+        IAsyncEnumerable<TResponse>
+    {
+        private readonly AsyncDuplexStreamingCall<TRequest, TResponse> _bidirectionalStream;
+        private readonly Action _rpcErrorAction;
+
+        public BidirectionalStream(AsyncDuplexStreamingCall<TRequest, TResponse> bidirectionalStream,
+            Action rpcErrorAction)
+        {
+            _bidirectionalStream = bidirectionalStream;
+            _rpcErrorAction = rpcErrorAction;
+        }
+
+        public async Task Write(TRequest request)
+        {
+            try
+            {
+                await _bidirectionalStream.RequestStream.WriteAsync(request);
+            }
+            catch (RpcException e)
+            {
+                _rpcErrorAction();
+
+                throw new TransportException(e);
+            }
+        }
+
+        public ValueTask DisposeAsync()
+        {
+            _bidirectionalStream.Dispose();
+
+            return default;
+        }
+
+        public async ValueTask<bool> MoveNextAsync()
+        {
+            try
+            {
+                return await _bidirectionalStream.ResponseStream.MoveNext(CancellationToken.None);
+            }
+            catch (RpcException e)
+            {
+                _rpcErrorAction();
+
+                throw new TransportException(e);
+            }
+        }
+
+        public TResponse Current => _bidirectionalStream.ResponseStream.Current;
+
+        public IAsyncEnumerator<TResponse> GetAsyncEnumerator(CancellationToken cancellationToken = new())
+        {
+            return this;
+        }
+    }
+
     public class InitializationFailureException : Exception
     {
         internal InitializationFailureException(string message) : base(message)

src/Ydb.Sdk/src/Services/Query/SessionPool.cs

@@ -47,7 +47,7 @@ protected override async Task<Session> CreateSession()
         {
             try
             {
-                await using var stream = _driver.StreamCall(QueryService.AttachSessionMethod, new AttachSessionRequest
+                await using var stream = _driver.ServerStreamCall(QueryService.AttachSessionMethod, new AttachSessionRequest
                     { SessionId = session.SessionId }, AttachSessionSettings);
 
                 if (!await stream.MoveNextAsync())
@@ -140,7 +140,7 @@ internal Session(Driver driver, SessionPool<Session> sessionPool, string session
         _driver = driver;
     }
 
-    internal Driver.StreamIterator<ExecuteQueryResponsePart> ExecuteQuery(
+    internal Driver.ServerStream<ExecuteQueryResponsePart> ExecuteQuery(
         string query,
         Dictionary<string, YdbValue>? parameters,
         ExecuteQuerySettings? settings,
@@ -161,7 +161,7 @@ internal Driver.StreamIterator<ExecuteQueryResponsePart> ExecuteQuery(
 
         request.Parameters.Add(parameters.ToDictionary(p => p.Key, p => p.Value.GetProto()));
 
-        return _driver.StreamCall(QueryService.ExecuteQueryMethod, request, settings);
+        return _driver.ServerStreamCall(QueryService.ExecuteQueryMethod, request, settings);
     }
 
     internal async Task<Status> CommitTransaction(string txId, GrpcRequestSettings? settings = null)

src/Ydb.Sdk/src/Services/Table/ExecuteScanQuery.cs

@@ -34,7 +34,7 @@ internal static ResultData FromProto(ExecuteScanQueryPartialResult resultProto)
 
 public class ExecuteScanQueryStream : StreamResponse<ExecuteScanQueryPartialResponse, ExecuteScanQueryPart>
 {
-    internal ExecuteScanQueryStream(Driver.StreamIterator<ExecuteScanQueryPartialResponse> iterator)
+    internal ExecuteScanQueryStream(Driver.ServerStream<ExecuteScanQueryPartialResponse> iterator)
         : base(iterator)
     {
     }
@@ -75,7 +75,7 @@ public ExecuteScanQueryStream ExecuteScanQuery(
 
         request.Parameters.Add(parameters.ToDictionary(p => p.Key, p => p.Value.GetProto()));
 
-        var streamIterator = _driver.StreamCall(
+        var streamIterator = _driver.ServerStreamCall(
             method: TableService.StreamExecuteScanQueryMethod,
             request: request,
             settings: settings

src/Ydb.Sdk/src/Services/Table/ReadTable.cs

@@ -39,7 +39,7 @@ internal static ResultData FromProto(ReadTableResult resultProto)
 
 public class ReadTableStream : StreamResponse<ReadTableResponse, ReadTablePart>
 {
-    internal ReadTableStream(Driver.StreamIterator<ReadTableResponse> iterator)
+    internal ReadTableStream(Driver.ServerStream<ReadTableResponse> iterator)
         : base(iterator)
     {
     }
@@ -74,7 +74,7 @@ public ReadTableStream ReadTable(string tablePath, ReadTableSettings? settings =
             Ordered = settings.Ordered
         };
 
-        var streamIterator = _driver.StreamCall(
+        var streamIterator = _driver.ServerStreamCall(
             method: TableService.StreamReadTableMethod,
             request: request,
             settings: settings