mg_transfer_block.h

// ---------------------------------------------------------------------
//
// Copyright (C) 2001 - 2018 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, redistribute
// it, and/or modify it under the terms of the GNU Lesser General
// Public License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE.md at
// the top level directory of deal.II.
//
// ---------------------------------------------------------------------

#ifndef dealii_mg_transfer_block_h
#define dealii_mg_transfer_block_h

#include <deal.II/base/config.h>

#include <deal.II/base/mg_level_object.h>

#include <deal.II/dofs/dof_handler.h>

#include <deal.II/lac/block_matrix_array.h>
#include <deal.II/lac/block_sparsity_pattern.h>
#include <deal.II/lac/block_vector.h>
#include <deal.II/lac/sparsity_pattern.h>
#include <deal.II/lac/vector_memory.h>

#include <deal.II/multigrid/mg_base.h>
#include <deal.II/multigrid/mg_constrained_dofs.h>

#include <memory>


DEAL_II_NAMESPACE_OPEN


template <int dim, int spacedim>
class DoFHandler;

/*
 * MGTransferBase is defined in mg_base.h
 */


class MGTransferBlockBase
{
public:
  MGTransferBlockBase();

  MGTransferBlockBase(const MGConstrainedDoFs &mg_constrained_dofs);

  DEAL_II_DEPRECATED
  MGTransferBlockBase(const AffineConstraints<double> &constraints,
                      const MGConstrainedDoFs &        mg_constrained_dofs);

  std::size_t
  memory_consumption() const;

protected:
  template <int dim, int spacedim>
  void
  build_matrices(const DoFHandler<dim, spacedim> &dof,
                 const DoFHandler<dim, spacedim> &mg_dof);

  // TODO: rename this to block_mask, in the same way as has already been done
  // in MGTransferComponent, and give it type BlockMask
  std::vector<bool> selected;

  unsigned int n_mg_blocks;

  // TODO: rename this to mg_block_mask, in the same way as has already been
  // done in MGTransferComponent, and give it type BlockMask
  std::vector<unsigned int> mg_block;

  mutable std::vector<std::vector<types::global_dof_index>> sizes;

  std::vector<types::global_dof_index> block_start;

  std::vector<std::vector<types::global_dof_index>> mg_block_start;

  DeclException0(ExcMatricesNotBuilt);

private:
  std::vector<std::shared_ptr<BlockSparsityPattern>> prolongation_sparsities;

protected:
  std::vector<std::shared_ptr<BlockSparseMatrix<double>>> prolongation_matrices;

  std::vector<std::vector<std::vector<std::pair<unsigned int, unsigned int>>>>
    copy_indices;

  SmartPointer<const MGConstrainedDoFs, MGTransferBlockBase>
    mg_constrained_dofs;
};

template <typename number>
class MGTransferBlock : public MGTransferBase<BlockVector<number>>,
                        private MGTransferBlockBase
{
public:
  MGTransferBlock();

  virtual ~MGTransferBlock() override;

  void
  initialize(const std::vector<number> &   factors,
             VectorMemory<Vector<number>> &memory);

  template <int dim, int spacedim>
  void
  build_matrices(const DoFHandler<dim, spacedim> &dof,
                 const DoFHandler<dim, spacedim> &mg_dof,
                 const std::vector<bool> &        selected);

  virtual void
  prolongate(const unsigned int         to_level,
             BlockVector<number> &      dst,
             const BlockVector<number> &src) const override;

  virtual void
  restrict_and_add(const unsigned int         from_level,
                   BlockVector<number> &      dst,
                   const BlockVector<number> &src) const override;

  template <int dim, typename number2, int spacedim>
  void
  copy_to_mg(const DoFHandler<dim, spacedim> &   mg_dof,
             MGLevelObject<BlockVector<number>> &dst,
             const BlockVector<number2> &        src) const;

  template <int dim, typename number2, int spacedim>
  void
  copy_from_mg(const DoFHandler<dim, spacedim> &         mg_dof,
               BlockVector<number2> &                    dst,
               const MGLevelObject<BlockVector<number>> &src) const;

  template <int dim, typename number2, int spacedim>
  void
  copy_from_mg_add(const DoFHandler<dim, spacedim> &         mg_dof,
                   BlockVector<number2> &                    dst,
                   const MGLevelObject<BlockVector<number>> &src) const;

  using MGTransferBlockBase::memory_consumption;

private:
  std::vector<number> factors;

  SmartPointer<VectorMemory<Vector<number>>, MGTransferBlock<number>> memory;
};


// TODO:[GK] Update documentation for copy_* functions

template <typename number>
class MGTransferBlockSelect : public MGTransferBase<Vector<number>>,
                              private MGTransferBlockBase
{
public:
  MGTransferBlockSelect();

  MGTransferBlockSelect(const MGConstrainedDoFs &mg_constrained_dofs);

  DEAL_II_DEPRECATED
  MGTransferBlockSelect(const AffineConstraints<double> &constraints,
                        const MGConstrainedDoFs &        mg_constrained_dofs);

  virtual ~MGTransferBlockSelect() override = default;

  template <int dim, int spacedim>
  void
  build_matrices(const DoFHandler<dim, spacedim> &dof,
                 const DoFHandler<dim, spacedim> &mg_dof,
                 unsigned int                     selected);

  void
  select(const unsigned int block);

  virtual void
  prolongate(const unsigned int    to_level,
             Vector<number> &      dst,
             const Vector<number> &src) const override;

  virtual void
  restrict_and_add(const unsigned int    from_level,
                   Vector<number> &      dst,
                   const Vector<number> &src) const override;

  template <int dim, typename number2, int spacedim>
  void
  copy_to_mg(const DoFHandler<dim, spacedim> &mg_dof,
             MGLevelObject<Vector<number>> &  dst,
             const Vector<number2> &          src) const;

  template <int dim, typename number2, int spacedim>
  void
  copy_from_mg(const DoFHandler<dim, spacedim> &    mg_dof,
               Vector<number2> &                    dst,
               const MGLevelObject<Vector<number>> &src) const;

  template <int dim, typename number2, int spacedim>
  void
  copy_from_mg_add(const DoFHandler<dim, spacedim> &    mg_dof,
                   Vector<number2> &                    dst,
                   const MGLevelObject<Vector<number>> &src) const;

  template <int dim, typename number2, int spacedim>
  void
  copy_to_mg(const DoFHandler<dim, spacedim> &mg_dof,
             MGLevelObject<Vector<number>> &  dst,
             const BlockVector<number2> &     src) const;

  template <int dim, typename number2, int spacedim>
  void
  copy_from_mg(const DoFHandler<dim, spacedim> &    mg_dof,
               BlockVector<number2> &               dst,
               const MGLevelObject<Vector<number>> &src) const;

  template <int dim, typename number2, int spacedim>
  void
  copy_from_mg_add(const DoFHandler<dim, spacedim> &    mg_dof,
                   BlockVector<number2> &               dst,
                   const MGLevelObject<Vector<number>> &src) const;

  std::size_t
  memory_consumption() const;

private:
  template <int dim, class OutVector, int spacedim>
  void
  do_copy_from_mg(const DoFHandler<dim, spacedim> &    mg_dof,
                  OutVector &                          dst,
                  const MGLevelObject<Vector<number>> &src,
                  const unsigned int                   offset) const;

  template <int dim, class OutVector, int spacedim>
  void
  do_copy_from_mg_add(const DoFHandler<dim, spacedim> &    mg_dof,
                      OutVector &                          dst,
                      const MGLevelObject<Vector<number>> &src,
                      const unsigned int                   offset) const;

  template <int dim, class InVector, int spacedim>
  void
  do_copy_to_mg(const DoFHandler<dim, spacedim> &mg_dof,
                MGLevelObject<Vector<number>> &  dst,
                const InVector &                 src,
                const unsigned int               offset) const;
  unsigned int selected_block;
};

//------------------------- inline function definition ------------------------
template <typename number>
inline void
MGTransferBlockSelect<number>::select(const unsigned int block)
{
  selected_block = block;
}

DEAL_II_NAMESPACE_CLOSE

#endif