AbstractISTLSolver.hpp

/*
  Copyright 2025 Equinor ASA

  This file is part of the Open Porous Media project (OPM).
  OPM is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.
  OPM is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
  You should have received a copy of the GNU General Public License
  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef OPM_ABSTRACTISTLSOLVER_HEADER_INCLUDED
#define OPM_ABSTRACTISTLSOLVER_HEADER_INCLUDED

#include <opm/common/Exceptions.hpp>
#include <opm/simulators/linalg/FlowLinearSolverParameters.hpp>
#include <opm/simulators/linalg/PropertyTree.hpp>

namespace Opm
{

template <class SparseMatrixAdapter, class Vector>
class AbstractISTLSolver
{
public:
#if HAVE_MPI
    using CommunicationType = Dune::OwnerOverlapCopyCommunication<int, int>;
#else
    using CommunicationType = Dune::Communication<int>;
#endif

    using Matrix = typename SparseMatrixAdapter::IstlMatrix;

    virtual ~AbstractISTLSolver() = default;

    virtual void eraseMatrix() = 0;

    virtual void setActiveSolver(int num) = 0;

    virtual int numAvailableSolvers() const = 0;

    virtual void prepare(const Matrix& M, Vector& b) = 0;

    virtual void prepare(const SparseMatrixAdapter& M, Vector& b) = 0;

    virtual void setResidual(Vector& b) = 0;

    virtual void getResidual(Vector& b) const = 0;

    virtual void setMatrix(const SparseMatrixAdapter& M) = 0;

    virtual bool solve(Vector& x) = 0;

    virtual int iterations() const = 0;

    virtual const CommunicationType* comm() const = 0;

    virtual int getSolveCount() const = 0;

protected:

    static bool checkConvergence(const Dune::InverseOperatorResult& result,
                                 const FlowLinearSolverParameters& parameters)
    {
        if (!result.converged) {
            if (result.reduction < parameters.relaxed_linear_solver_reduction_) {
                std::stringstream ss;
                ss << "Full linear solver tolerance not achieved. The reduction is:" << result.reduction << " after "
                   << result.iterations << " iterations ";
                OpmLog::warning(ss.str());
                return true;
            }
        }
        // Check for failure of linear solver.
        if (!parameters.ignoreConvergenceFailure_ && !result.converged) {
            const std::string msg("Convergence failure for linear solver.");
            OPM_THROW_NOLOG(NumericalProblem, msg);
        }

        return result.converged;
    }
};
} // namespace Opm

#endif