be/src/service/data-stream-service.h

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#ifndef IMPALA_SERVICE_DATA_STREAM_SERVICE_H
#define IMPALA_SERVICE_DATA_STREAM_SERVICE_H

#include "gen-cpp/data_stream_service.service.h"

#include "common/status.h"
#include "runtime/mem-tracker.h"

namespace kudu {
namespace rpc {
class RpcContext;
} // namespace rpc
} // namespace kudu

namespace impala {

class RpcMgr;

/// This is singleton class which provides data transmission services between fragment
/// instances. The client for this service is implemented in KrpcDataStreamSender.
/// The processing of incoming requests is implemented in KrpcDataStreamRecvr.
/// KrpcDataStreamMgr is responsible for routing the incoming requests to the
/// appropriate receivers.
class DataStreamService : public DataStreamServiceIf {
 public:
  DataStreamService();

  /// Initializes the service by registering it with the singleton RPC manager.
  /// This mustn't be called until RPC manager has been initialized.
  Status Init();

  /// Notifies the receiver to close the data stream specified in 'request'.
  /// The receiver replies to the client with a status serialized in 'response'.
  virtual void EndDataStream(const EndDataStreamRequestPB* request,
      EndDataStreamResponsePB* response, kudu::rpc::RpcContext* context);

  /// Sends a row batch to the receiver specified in 'request'.
  /// The receiver replies to the client with a status serialized in 'response'.
  virtual void TransmitData(const TransmitDataRequestPB* request,
      TransmitDataResponsePB* response, kudu::rpc::RpcContext* context);

  MemTracker* mem_tracker() { return mem_tracker_.get(); }

 private:
  /// Tracks the memory usage of the payloads in the service queue.
  std::unique_ptr<MemTracker> mem_tracker_;
};

} // namespace impala
#endif // IMPALA_SERVICE_DATA_STREAM_SERVICE_H