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// .NAME Partition - Partition MPI processors into cartesian grid
//
// .SECTION Description
// Partition allows MPI to divide the number of processors it is given and
// to set the position of this processor within the Cartesian grid.  Using
// that information with wraparound, all neighbors of a processor are
// also computed.  This class is static and will be shared by all classes
// within the infrastructure.

#ifndef Partition_h
#define Partition_h

#include "vtkCosmoHaloFinderModule.h"

#include "Definition.h"
#include <string>
#include <vector>

namespace cosmotk {

class VTKCOSMOHALOFINDER_EXPORT Partition {
public:
  Partition();
  ~Partition();

  // Control MPI and the Cartesian topology
  //static void initialize(int& argc, char** argv);
  static void initialize(MPI_Comm comm = MPI_COMM_WORLD);
  static void finalize();
  static bool isInitialized() { return initialized != 0; }

  // Set the processor numbers of neighbors in all directions
  static void setNeighbors();

#ifndef USE_SERIAL_COSMO
  static MPI_Comm getComm()       { return cartComm; }
#endif

  static int  getMyProc()               { return myProc; }
  static int  getNumProc()              { return numProc; }

  static void getDecompSize(int size[]);
  static void getMyPosition(int pos[]);
  static void getNeighbors(int neigh[]);

  static int  getNeighbor(int xpos, int ypos, int zpos);

private:
  static int myProc;                    // My processor number
  static int numProc;                   // Total number of processors
  static int initialized;

#ifndef USE_SERIAL_COSMO
  static MPI_Comm cartComm;             // Cartesian communicator
#endif

  static int decompSize[DIMENSION];     // Number of processors in each dim
  static int myPosition[DIMENSION];     // My index in cartesian communicator

  static int neighbor[NUM_OF_NEIGHBORS];// Neighbor processor ids
};

} // END namespace cosmotk
#endif
