vector_ghost_communicator.h

Go to the documentation of this file.

#ifndef CHITECH_VECTOR_GHOST_COMMUNICATOR_H
#define CHITECH_VECTOR_GHOST_COMMUNICATOR_H
 
#include <vector>
#include <cstdint>
#include <map>
 
#include <mpi.h>
 
namespace chi_math
{
 
/**Vector with allocation space for ghosts.*/
class VectorGhostCommunicator
{
 
public:
  VectorGhostCommunicator(uint64_t local_size,
                          uint64_t global_size,
                          const std::vector<int64_t>& ghost_ids,
                          MPI_Comm communicator);
 
  /**Copy constructor.*/
  VectorGhostCommunicator(const VectorGhostCommunicator& other);
 
  /**Move constructor.*/
  VectorGhostCommunicator(VectorGhostCommunicator&& other) noexcept;
 
  uint64_t LocalSize() const { return local_size_; }
  uint64_t GlobalSize() const { return global_size_; }
 
  uint64_t NumGhosts() const { return ghost_ids_.size(); }
  const std::vector<int64_t>& GhostIndices() const { return ghost_ids_; }
 
  MPI_Comm Communicator() const { return comm_; }
 
  int64_t MapGhostToLocal(int64_t ghost_id) const;
 
  void CommunicateGhostEntries(std::vector<double>& ghosted_vector) const;
 
  std::vector<double> MakeGhostedVector() const;
  std::vector<double>
  MakeGhostedVector(const std::vector<double>& local_vector) const;
 
protected:
  const uint64_t local_size_;
  const uint64_t global_size_;
  const std::vector<int64_t> ghost_ids_;
  const MPI_Comm comm_;
 
  const int location_id_;
  const int process_count_;
  const std::vector<uint64_t> extents_;
 
  struct CachedParallelData
  {
    std::vector<int> sendcounts_;
    std::vector<int> senddispls_;
    std::vector<int> recvcounts_;
    std::vector<int> recvdispls_;
 
    std::vector<int64_t> local_ids_to_send_;
    std::map<int64_t, size_t> ghost_to_recv_map_;
  };
 
  const CachedParallelData cached_parallel_data_;
 
private:
  int FindOwnerPID(int64_t global_id) const;
  CachedParallelData MakeCachedParallelData();
};
 
}//namespace chi_math
 
#endif //CHITECH_VECTOR_GHOST_COMMUNICATOR_H