setup_buffer_matrix Subroutine

   SUBROUTINE setup_buffer_matrix(matrix, source_matrix, &
                                  index_size, data_size, data_buffer, data_memory_type)
      TYPE(dbcsr_type), INTENT(INOUT)                    :: matrix
      TYPE(dbcsr_type), INTENT(IN)                       :: source_matrix
      INTEGER, INTENT(IN), OPTIONAL                      :: index_size, data_size
      TYPE(dbcsr_data_obj), INTENT(IN), OPTIONAL         :: data_buffer
      TYPE(dbcsr_memtype_type), INTENT(IN), OPTIONAL     :: data_memory_type

      matrix = dbcsr_type()
      CALL dbcsr_create(matrix, &
                        template=source_matrix, &
                        name=TRIM("Buffer of "//TRIM(source_matrix%name)), &
                        nze=data_size, &
                        data_buffer=data_buffer, &
                        data_memory_type=data_memory_type, &
                        index_memory_type=memtype_mpi_buffer)
      IF (PRESENT(data_size)) THEN
         CALL dbcsr_data_ensure_size( &
            matrix%data_area, &
            data_size, nocopy=.TRUE.)
      END IF
      IF (PRESENT(index_size)) THEN
         CALL ensure_array_size( &
            matrix%index, &
            ub=index_size, nocopy=.TRUE., &
            memory_type=dbcsr_get_index_memory_type(matrix))
      END IF
      matrix%negate_real = source_matrix%negate_real
      matrix%negate_imaginary = source_matrix%negate_imaginary
      matrix%local_indexing = source_matrix%local_indexing
      matrix%list_indexing = source_matrix%list_indexing
      !
      IF (source_matrix%has_local_rows) THEN
         matrix%local_rows = source_matrix%local_rows
         CALL array_hold(matrix%local_rows)
         matrix%has_local_rows = .TRUE.
      END IF
      IF (source_matrix%has_global_rows) THEN
         matrix%global_rows = source_matrix%global_rows
         CALL array_hold(matrix%global_rows)
         matrix%has_global_rows = .TRUE.
      END IF
      IF (source_matrix%has_local_cols) THEN
         matrix%local_cols = source_matrix%local_cols
         CALL array_hold(matrix%local_cols)
         matrix%has_local_cols = .TRUE.
      END IF
      IF (source_matrix%has_global_cols) THEN
         matrix%global_cols = source_matrix%global_cols
         CALL array_hold(matrix%global_cols)
         matrix%has_global_cols = .TRUE.
      END IF

   END SUBROUTINE setup_buffer_matrix