DofMap.h

// Copyright (C) 2007-2020 Anders Logg and Garth N. Wells
//
// This file is part of DOLFINx (https://www.fenicsproject.org)
//
// SPDX-License-Identifier:    LGPL-3.0-or-later
 
#pragma once
 
#include <cstdlib>
#include <dolfinx/common/MPI.h>
#include <dolfinx/graph/AdjacencyList.h>
#include <dolfinx/graph/scotch.h>
#include <functional>
#include <memory>
#include <utility>
#include <vector>
#include <xtl/xspan.hpp>
 
namespace dolfinx::common
{
class IndexMap;
}
 
namespace dolfinx::mesh
{
class Topology;
}
 
namespace dolfinx::fem
{
class ElementDofLayout;
 
graph::AdjacencyList<std::int32_t>
transpose_dofmap(const graph::AdjacencyList<std::int32_t>& dofmap,
                 std::int32_t num_cells);
 
 
class DofMap
{
public:
  template <typename U,
            typename = std::enable_if_t<std::is_same<
                graph::AdjacencyList<std::int32_t>, std::decay_t<U>>::value>>
  DofMap(std::shared_ptr<const ElementDofLayout> element,
         std::shared_ptr<const common::IndexMap> index_map, int index_map_bs,
         U&& dofmap, int bs)
      : element_dof_layout(element), index_map(index_map),
        _index_map_bs(index_map_bs), _dofmap(std::forward<U>(dofmap)), _bs(bs)
  {
    // Do nothing
  }
 
  // Copy constructor
  DofMap(const DofMap& dofmap) = delete;
 
  DofMap(DofMap&& dofmap) = default;
 
  virtual ~DofMap() = default;
 
  // Copy assignment
  DofMap& operator=(const DofMap& dofmap) = delete;
 
  DofMap& operator=(DofMap&& dofmap) = default;
 
  xtl::span<const std::int32_t> cell_dofs(int cell) const
  {
    return _dofmap.links(cell);
  }
 
  int bs() const noexcept;
 
  DofMap extract_sub_dofmap(const std::vector<int>& component) const;
 
  std::pair<std::unique_ptr<DofMap>, std::vector<std::int32_t>> collapse(
      MPI_Comm comm, const mesh::Topology& topology,
      const std::function<std::vector<int>(
          const graph::AdjacencyList<std::int32_t>&)>& reorder_fn
      = [](const graph::AdjacencyList<std::int32_t>& g)
      { return graph::scotch::compute_gps(g, 2).first; }) const;
 
  const graph::AdjacencyList<std::int32_t>& list() const;
 
  std::shared_ptr<const ElementDofLayout> element_dof_layout;
 
  std::shared_ptr<const common::IndexMap> index_map;
 
  int index_map_bs() const;
 
private:
  // Block size for the IndexMap
  int _index_map_bs = -1;
 
  // Cell-local-to-dof map (dofs for cell dofmap[cell])
  graph::AdjacencyList<std::int32_t> _dofmap;
 
  // Block size for the dofmap
  int _bs = -1;
};
} // namespace dolfinx::fem