direct.hpp

// SPDX-FileCopyrightText: 2017 - 2025 The Ginkgo authors
//
// SPDX-License-Identifier: BSD-3-Clause
 
#ifndef GKO_PUBLIC_CORE_SOLVER_DIRECT_HPP_
#define GKO_PUBLIC_CORE_SOLVER_DIRECT_HPP_
 
 
#include <ginkgo/core/base/lin_op.hpp>
#include <ginkgo/core/config/config.hpp>
#include <ginkgo/core/config/registry.hpp>
#include <ginkgo/core/factorization/factorization.hpp>
#include <ginkgo/core/solver/solver_base.hpp>
#include <ginkgo/core/solver/triangular.hpp>
 
 
namespace gko {
namespace experimental {
namespace solver {
 

template <typename ValueType, typename IndexType>
class Direct : public EnableLinOp<Direct<ValueType, IndexType>>,
               public gko::solver::EnableSolverBase<
                   Direct<ValueType, IndexType>,
                   factorization::Factorization<ValueType, IndexType>>,
               public Transposable {
    friend class EnablePolymorphicObject<Direct, LinOp>;
    GKO_ASSERT_SUPPORTED_VALUE_AND_INDEX_TYPE;
 
public:
    using value_type = ValueType;
    using index_type = IndexType;
    using factorization_type =
        factorization::Factorization<value_type, index_type>;
    using transposed_type = Direct;
 
    std::unique_ptr<LinOp> transpose() const override;
 
    std::unique_ptr<LinOp> conj_transpose() const override;
 
    class Factory;
 
    struct parameters_type : enable_parameters_type<parameters_type, Factory> {
        gko::size_type GKO_FACTORY_PARAMETER_SCALAR(num_rhs, 1u);

        std::shared_ptr<const LinOpFactory> GKO_DEFERRED_FACTORY_PARAMETER(
            factorization);
    };
    GKO_ENABLE_LIN_OP_FACTORY(Direct, parameters, Factory);
    GKO_ENABLE_BUILD_METHOD(Factory);

    static parameters_type parse(
        const config::pnode& config, const config::registry& context,
        const config::type_descriptor& td_for_child =
            config::make_type_descriptor<ValueType, IndexType>());

    Direct(const Direct&);

    Direct(Direct&&);
 
    Direct& operator=(const Direct&);
 
    Direct& operator=(Direct&&);
 
protected:
    explicit Direct(std::shared_ptr<const Executor> exec);
 
    Direct(const Factory* factory, std::shared_ptr<const LinOp> system_matrix);
 
    void apply_impl(const LinOp* b, LinOp* x) const override;
 
    void apply_impl(const LinOp* alpha, const LinOp* b, const LinOp* beta,
                    LinOp* x) const override;
 
private:
    using lower_type = gko::solver::LowerTrs<value_type, index_type>;
    using upper_type = gko::solver::UpperTrs<value_type, index_type>;
 
    std::unique_ptr<lower_type> lower_solver_;
    std::unique_ptr<upper_type> upper_solver_;
};
 
 
}  // namespace solver
}  // namespace experimental
 
 
namespace solver {
 
 
template <typename ValueType, typename IndexType>
struct workspace_traits<
    gko::experimental::solver::Direct<ValueType, IndexType>> {
    using Solver = gko::experimental::solver::Direct<ValueType, IndexType>;
    // number of vectors used by this workspace
    static int num_vectors(const Solver&);
    // number of arrays used by this workspace
    static int num_arrays(const Solver&);
    // array containing the num_vectors names for the workspace vectors
    static std::vector<std::string> op_names(const Solver&);
    // array containing the num_arrays names for the workspace vectors
    static std::vector<std::string> array_names(const Solver&);
    // array containing all varying scalar vectors (independent of problem size)
    static std::vector<int> scalars(const Solver&);
    // array containing all varying vectors (dependent on problem size)
    static std::vector<int> vectors(const Solver&);
 
    // intermediate vector
    constexpr static int intermediate = 0;
};
 
 
}  // namespace solver
}  // namespace gko
 
#endif  // GKO_PUBLIC_CORE_SOLVER_DIRECT_HPP_