Tpetra_Details_getGraphDiagOffsets_decl.hpp

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// @HEADER
// *****************************************************************************
//          Tpetra: Templated Linear Algebra Services Package
//
// Copyright 2008 NTESS and the Tpetra contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER
 
#ifndef TPETRA_DETAILS_GETGRAPHDIAGOFFSETS_DECL_HPP
#define TPETRA_DETAILS_GETGRAPHDIAGOFFSETS_DECL_HPP
 
 
#include "TpetraCore_config.h"
#include "Kokkos_Core.hpp"
#include "KokkosSparse_StaticCrsGraph.hpp"
#include "Tpetra_Details_LocalMap.hpp"
#include <type_traits>
 
namespace Tpetra {
namespace Details {
namespace Impl {
 
template <class LO,
          class GO,
          class DeviceType,
          class DiagOffsetType = size_t>
class GetGraphDiagOffsets {
 public:
  typedef typename DeviceType::device_type device_type;
  typedef DiagOffsetType diag_offset_type;
  typedef ::Kokkos::View<diag_offset_type*,
                         device_type,
                         ::Kokkos::MemoryUnmanaged>
      diag_offsets_type;
  using local_graph_device_type = ::KokkosSparse::StaticCrsGraph<LO,
                                                                 ::Kokkos::LayoutLeft,
                                                                 device_type, void, size_t>;
  typedef ::Tpetra::Details::LocalMap<LO, GO, device_type> local_map_type;
  typedef ::Kokkos::View<const typename local_graph_device_type::size_type*,
                         ::Kokkos::LayoutLeft,
                         device_type,
                         ::Kokkos::MemoryUnmanaged>
      row_offsets_type;
  // This is unmanaged for performance, because we need to take
  // subviews inside the functor.
  typedef ::Kokkos::View<const LO*,
                         ::Kokkos::LayoutLeft,
                         device_type,
                         ::Kokkos::MemoryUnmanaged>
      lcl_col_inds_type;
 
  GetGraphDiagOffsets(const diag_offsets_type& diagOffsets,
                      const local_map_type& lclRowMap,
                      const local_map_type& lclColMap,
                      const row_offsets_type& ptr,
                      const lcl_col_inds_type& ind,
                      const bool isSorted);
 
  KOKKOS_FUNCTION void operator()(const LO& lclRowInd) const;
 
 private:
  diag_offsets_type diagOffsets_;
  local_map_type lclRowMap_;
  local_map_type lclColMap_;
  row_offsets_type ptr_;
  lcl_col_inds_type ind_;
  bool isSorted_;
};
 
}  // namespace Impl
 
template <class DiagOffsetsType,
          class LclMapType,
          class RowOffsetsType,
          class LclColIndsType>
void getGraphDiagOffsets(const DiagOffsetsType& diagOffsets,
                         const LclMapType& lclRowMap,
                         const LclMapType& lclColMap,
                         const RowOffsetsType& ptr,
                         const LclColIndsType& ind,
                         const bool isSorted) {
  static_assert(Kokkos::is_view<DiagOffsetsType>::value,
                "DiagOffsetsType (the type of diagOffsets) must be a Kokkos::View.");
  static_assert(Kokkos::is_view<RowOffsetsType>::value,
                "RowOffsetsType (the type of ptr) must be a Kokkos::View.");
  static_assert(Kokkos::is_view<LclColIndsType>::value,
                "LclColIndsType (the type of ind) must be a Kokkos::View.");
  static_assert(static_cast<int>(DiagOffsetsType::rank) == 1,
                "DiagOffsetsType (the type of diagOffsets) must be a rank-1 Kokkos::View.");
  static_assert(static_cast<int>(RowOffsetsType::rank) == 1,
                "RowOffsetsType (the type of ptr) must be a rank-1 Kokkos::View.");
  static_assert(static_cast<int>(LclColIndsType::rank) == 1,
                "LclColIndsType (the type of ind) must be a rank-1 Kokkos::View.");
  typedef typename DiagOffsetsType::non_const_value_type diag_offset_type;
  static_assert(std::is_same<typename DiagOffsetsType::value_type, diag_offset_type>::value,
                "DiagOffsetsType (the type of diagOffsets) must be a nonconst "
                "Kokkos::View, since it is the output argument of this function.");
  static_assert(std::is_integral<diag_offset_type>::value,
                "The type of each entry of diagOffsets must be an integer.");
  typedef typename LclColIndsType::non_const_value_type local_ordinal_type;
  static_assert(std::is_integral<local_ordinal_type>::value,
                "The type of each entry of ind (the array of column indices) "
                "must be an integer.");
  static_assert(sizeof(diag_offset_type) >= sizeof(local_ordinal_type),
                "Diagonal offset type must be big enough to count the number "
                "of column indices, since the diagonal entry (if it exists) "
                "may be anywhere in a row.");
  typedef typename RowOffsetsType::non_const_value_type row_offset_type;
  static_assert(std::is_integral<row_offset_type>::value,
                "The type of each entry of ptr must be an integer.");
 
  typedef typename LclMapType::local_ordinal_type LO;
  typedef typename LclMapType::global_ordinal_type GO;
  typedef typename LclMapType::device_type DT;
 
  typedef Impl::GetGraphDiagOffsets<LO, GO, DT, diag_offset_type> impl_type;
  // The functor's constructor runs the functor.
  impl_type impl(diagOffsets, lclRowMap, lclColMap, ptr, ind, isSorted);
}
 
}  // namespace Details
}  // namespace Tpetra
 
#endif  // TPETRA_DETAILS_GETGRAPHDIAGOFFSETS_DECL_HPP