rpc_dart_transports 1.6.1

RPC Dart Transports library

RPC Dart - Transports

Transport implementations for RPC Dart. Provides ready transports.

Core concepts

• Transport — concrete implementation of the IRpcTransport interface.
• Client/Server transports — client-side connectors and server-side handlers.
• Multiplexing — many RPCs over one connection where supported.
• Zero-copy — supported where transport permits in-process object transfer.
• Health monitoring — each transport exposes health() snapshots and reconnect() attempts to simplify diagnostics.

Supported transports

• WebSocketTransport — bidirectional real-time transport with reconnection and optional multiplexing.
• IsolateTransport — efficient communication between Dart isolates, supports zero-copy for in-process objects.
• Http2Transport — HTTP/2 based transport with gRPC-compatible framing, TLS support and stream multiplexing.
• Http1Transport — unary-only HTTP/1.1 fallback that wraps every request in a POST and adds x-rpc-integrity checksums to guarantee payload integrity when a full gRPC stack is unavailable.

HTTP/1.1 transport (unary only)

When you cannot rely on HTTP/2 but still need RPC calls, RpcHttp1CallerTransport/RpcHttp1Server send a single unary request per RPC and rely on x-rpc-integrity (SHA256 over the framed payload) so both sides can detect tampering. There is no multiplexing or streaming—each call closes the request/response pair as soon as the body is exchanged. Example:

final server = RpcHttp1Server.createWithContracts(
  host: 'localhost',
  port: 8081,
  contracts: [MyServiceContract()],
);
await server.start();

final transport = RpcHttp1CallerTransport.connect(
  Uri.parse('http://localhost:8081'),
);
final caller = RpcCallerEndpoint(transport: transport);

final response = await caller.unaryRequest<RpcString, RpcString>(
  serviceName: 'MyService',
  methodName: 'Echo',
  requestCodec: RpcString.codec,
  responseCodec: RpcString.codec,
  request: RpcString('hello over HTTP/1.1'),
);
print('Server replied: ${response.value}');

WebSocket transport notes

• Формат кадра: [streamId:4][flags:1][gRPC_frame...], где gRPC_frame — 5-байтовый префикс gRPC + payload.
• Для больших сообщений можно включить чанкование по WebSocket (enableChunking: true в RpcWebSocketTransportBase конструкторах в rpc_dart_transports). Это режет gRPC frame на куски с дополнительным chunk-header и собирает обратно на приёме.
• По умолчанию чанкование выключено ради обратной совместимости: включайте только если обе стороны используют версию с поддержкой chunked флагов.