Capsule.h

/*
 * Capsule.h
 *
 *  Created on: Dec 7, 2016
 *      Author: wfgtemplates and pointers
 */

#ifndef CAPSULE_H_
#define CAPSULE_H_

/// \cond EXCLUDE_FROM_DOXYGEN
#include <string>
/// \endcond

namespace adios
{

/**
 * Base class that raw data and metadata buffers, used by Engine.
 * Derived classes will allocate their own buffer in different memory spaces.
 * e.g. locally (heap) or in shared memory (virtual memory)
 */
class Capsule
{

public:
  const std::string m_Type;       ///< buffer type
  const std::string m_AccessMode; ///< 'w': write, 'r': read, 'a': append

  std::size_t m_DataPosition = 0; ///< position in current data buffer (not
                                  /// included data flushed to transports)
  std::size_t m_DataAbsolutePosition =
      0; ///< includes the data flushed to transports

  std::size_t m_MetadataPosition = 0; ///< position in metadata buffer

  /**
   * Base class constructor providing type from derived class and accessMode
   * @param type derived class type
   * @param accessMode 'w':write, 'r':read, 'a':append
   * @param rankMPI current MPI rank
   * @param debugMode
   */
  Capsule(const std::string type, const std::string accessMode,
          const int rankMPI, const bool debugMode);

  virtual ~Capsule();

  virtual char *GetData() = 0; ///< return the pointer to the raw data buffer
  virtual char *
  GetMetadata() = 0; ///< return the pointer to the raw metadata buffer

  virtual std::size_t GetDataSize() const = 0; ///< get current data buffer size
  virtual std::size_t
  GetMetadataSize() const = 0; ///< get current metadata buffer size

  virtual void ResizeData(const std::size_t size); ///< resize data buffer
  virtual void
  ResizeMetadata(const std::size_t size); ///< resize metadata buffer

protected:
  const int m_RankMPI = 0;        ///< current MPI rank
  const bool m_DebugMode = false; ///< true: extra checks
};

} // end namespace

#endif /* CAPSULE_H_ */