feat: initial commit impl reader

Author: KirillKurdyukov

src/Ydb.Sdk/src/IDriver.cs

@@ -213,7 +213,7 @@ public async ValueTask<bool> MoveNextAsync()
     }
 }
 
-public class BidirectionalStream<TRequest, TResponse> : IBidirectionalStream<TRequest, TResponse>
+internal class BidirectionalStream<TRequest, TResponse> : IBidirectionalStream<TRequest, TResponse>
 {
     private readonly AsyncDuplexStreamingCall<TRequest, TResponse> _stream;
     private readonly Action<RpcException> _rpcErrorAction;

src/Ydb.Sdk/src/Services/Topic/Exceptions.cs

@@ -17,7 +17,20 @@ public WriterException(string message, Exception inner) : base(message, inner)
 
 public class ReaderException : Exception
 {
-    protected ReaderException(string message) : base(message)
+    public ReaderException(string message) : base(message)
     {
+        Status = new Status(StatusCode.Unspecified);
     }
+
+    public ReaderException(string message, Status status) : base(message + ": " + status)
+    {
+        Status = status;
+    }
+
+    public ReaderException(string message, Driver.TransportException e) : base(message, e)
+    {
+        Status = e.Status;
+    }
+
+    public Status Status { get; }
 }

src/Ydb.Sdk/src/Services/Topic/IReader.cs

@@ -2,9 +2,9 @@
 
 namespace Ydb.Sdk.Services.Topic;
 
-public interface IReader<TValue>
+public interface IReader<TValue> : IDisposable
 {
-    public Task<TValue> ReadAsync();
+    public ValueTask<Message<TValue>> ReadAsync(CancellationToken cancellationToken = default);
 
-    public Task<Message<TValue>> ReadMessageAsync();
+    public ValueTask<IReadOnlyList<Message<TValue>>> ReadBatchAsync(CancellationToken cancellationToken = default);
 }

src/Ydb.Sdk/src/Services/Topic/Reader/Message.cs

@@ -1,5 +1,45 @@
+using Google.Protobuf;
+using Google.Protobuf.Collections;
+using Google.Protobuf.WellKnownTypes;
+using Ydb.Topic;
+
 namespace Ydb.Sdk.Services.Topic.Reader;
 
 public class Message<TValue>
 {
+    internal Message(TValue data, string topic, string producerId)
+    {
+        Data = data;
+        Topic = topic;
+        ProducerId = producerId;
+    }
+
+    public TValue Data { get; }
+
+    /// <summary>
+    /// The topic associated with the message.
+    /// </summary>
+    public string Topic { get; }
+
+    public string ProducerId { get; }
+
+    public Task Commit()
+    {
+        throw new NotImplementedException();
+    }
+}
+
+public class BatchMessage<TValue>
+{
+    public BatchMessage(IReadOnlyCollection<Message<TValue>> batch)
+    {
+        Batch = batch;
+    }
+
+    public IReadOnlyCollection<Message<TValue>> Batch { get; }
+
+    public Task Commit()
+    {
+        throw new NotImplementedException();
+    }
 }