/**
 * @file   comm_info.hpp
 * @author Julian Iseringhausen <isering@ins.uni-bonn.de>
 * @date   Mon Nov 21 13:27:22 2011
 *
 * @brief  Stores some MPI-relevant information.
 *
 */

#ifndef COMM_INFO_HPP_
#define COMM_INFO_HPP_

#ifndef HAVE_MPI
#error MPI is needed to compile this class
#endif

#include <map>

#include "base/tuple.hpp"
#include "comm/mpi/key.hpp"

namespace VMG
{

class Index;
class Grid;
class GridIteratorSet;

namespace MPI
{

class CommInfo
{
public:
  CommInfo();
 virtual ~CommInfo();

  MPI_Comm GetCommunicator(const Grid& grid);
  MPI_Comm GetUnionCommunicator(const Grid& grid_1, const Grid& grid_2);

  MPI_Datatype GetDatatypeSubarray(const Grid& grid, const GridIteratorSet& bounds);
  MPI_Datatype GetDatatypeSubarray(const Index& begin, const Index& end, const Index& size_total);

  Index Pos(const Grid& grid);
  Index Procs(const Grid& grid);

  void SetCommGlobal(MPI_Comm& comm_global_)
  {
    comm_global = comm_global_;
  }

private:
  std::map<Key, MPI_Comm> communicators;
  std::map<Key, MPI_Datatype> datatypes;

  MPI_Comm comm_global;
  int max_level;

  static Index GetGlobalDims(MPI_Comm comm, Index pos);
};

}

}

#endif /* COMM_INFO_HPP_ */