TransportR 0.6.0

TransportR

Core library containing interfaces, protocols, and abstractions for the TransportR distributed data transfer solution.

Purpose

This project defines the foundational contracts and the binary protocol, and holds the hub services that need no network stack: the in-memory state store, the bridge and session state machines, the transfer manager and the cleanup services. It references no SignalR or ASP.NET Core package.

Key Interfaces

IBatchSerializer<T>

public interface IBatchSerializer<T>
{
    Task SerializeBatchAsync(Stream destination, List<T> batch);
    Task<List<T>?> DeserializeBatchAsync(Stream source);
}

The item type is on the interface, not on the call. A per-call generic would claim that every implementation carries every type, which none can and one cannot at all: a serializer built on Apache Arrow carries record batches only, and on a generic contract it could reject anything else only by throwing at the first batch. Typed here, the mismatch is a compile error.

IDataSender<T> / IDataReceiver<T>

public interface IDataSender<T> : IDataClient
{
    Task<Send<T>> InitTransferAsync(Guid targetClientId, int? batchSize = null);
    Task<List<ClientInfo>> GetReceiversAsync(CancellationToken ct = default);
    event Func<Send<T>, Task> OnSendRequested;   // a transfer the hub's host opened
}

public interface IDataReceiver<T> : IDataClient
{
    event Func<Receive<T>, Task> OnTransferStarted;
}

ITransferManager

// For unit testing hub components
public interface ITransferManager { ... }

Protocols

The chunk types and the protocol flow are described in TransportRArchitecture.md.

Binary Header (v2)

30-byte fixed header using BinaryPrimitives (zero external dependencies). The version byte is 2 (ChunkHeader.CurrentVersion); a reader rejects any other value.

│ Version │ Type │ PayloadLen │ BatchId │ Count │ TransferId │ [Payload] │
│ 1 byte  │ 1 b  │ 4 bytes    │ 4 bytes │ 4 b   │ 16 bytes   │ variable  │

Dependencies

• Microsoft.Extensions.Hosting.Abstractions, Microsoft.Extensions.Logging.Abstractions, Microsoft.Extensions.Options - abstractions only