TpetraExt_PointToBlockDiagPermute_decl.hpp

// @HEADER
// *****************************************************************************
//      TpetraExt: Tpetra Extended - Linear Algebra Services Package
//
// Copyright 2025 NTESS
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER
 
#ifndef TPETRAEXT_POINTTOBLOCKDIAGPERMUTE_DECL_HPP
#define TPETRAEXT_POINTTOBLOCKDIAGPERMUTE_DECL_HPP
 
#include "Teuchos_ParameterList.hpp"
#include "Teuchos_RCP.hpp"
#include "Tpetra_CrsMatrix.hpp"
#include "Tpetra_MultiVector.hpp"
 
namespace Tpetra::Ext {
 
template <class Scalar        = ::Tpetra::Details::DefaultTypes::scalar_type,
          class LocalOrdinal  = ::Tpetra::Details::DefaultTypes::local_ordinal_type,
          class GlobalOrdinal = ::Tpetra::Details::DefaultTypes::global_ordinal_type,
          class Node          = ::Tpetra::Details::DefaultTypes::node_type>
class PointToBlockDiagPermute {
 public:
  using map_type    = Tpetra::Map<LocalOrdinal, GlobalOrdinal, Node>;
  using crs_type    = Tpetra::CrsMatrix<Scalar, LocalOrdinal, GlobalOrdinal, Node>;
  using mv_type     = Tpetra::MultiVector<Scalar, LocalOrdinal, GlobalOrdinal, Node>;
  using vector_type = Tpetra::Vector<Scalar, LocalOrdinal, GlobalOrdinal, Node>;
 
  explicit PointToBlockDiagPermute(const crs_type& A);
 
  virtual ~PointToBlockDiagPermute() = default;
 
  int setParameters(Teuchos::ParameterList& list);
  int compute();
 
  Teuchos::RCP<crs_type> createCrsMatrix() const { return blockDiagMatrix_; }
 
 private:
  const crs_type* matrix_;
  Teuchos::ParameterList list_;
 
  bool purelyLocalMode_;
  bool contiguousBlockMode_;
  int contiguousBlockSize_;
 
  int numBlocks_;
  Teuchos::Array<int> blockStarts_;
  Teuchos::Array<GlobalOrdinal> blockGids_;
 
  Teuchos::RCP<const map_type> compatibleMap_;
  Teuchos::RCP<crs_type> blockDiagMatrix_;
 
  void cleanupBlockInfo();
  int setupContiguousMode();
  int extractBlockDiagonal();
};
 
}  // namespace Tpetra::Ext
 
#endif