sparsity_csr.hpp

// SPDX-FileCopyrightText: 2017 - 2025 The Ginkgo authors
//
// SPDX-License-Identifier: BSD-3-Clause
 
#ifndef GKO_PUBLIC_CORE_MATRIX_SPARSITY_CSR_HPP_
#define GKO_PUBLIC_CORE_MATRIX_SPARSITY_CSR_HPP_
 
 
#include <vector>
 
#include <ginkgo/core/base/array.hpp>
#include <ginkgo/core/base/lin_op.hpp>
#include <ginkgo/core/base/polymorphic_object.hpp>
 
 
namespace gko {
namespace matrix {
 
 
template <typename ValueType, typename IndexType>
class Csr;
 
 
template <typename ValueType>
class Dense;
 
 
template <typename ValueType, typename IndexType>
class Fbcsr;
 

template <typename ValueType = default_precision, typename IndexType = int32>
class SparsityCsr : public EnableLinOp<SparsityCsr<ValueType, IndexType>>,
                    public ConvertibleTo<Csr<ValueType, IndexType>>,
                    public ConvertibleTo<Dense<ValueType>>,
                    public ReadableFromMatrixData<ValueType, IndexType>,
                    public WritableToMatrixData<ValueType, IndexType>,
                    public Transposable {
    friend class EnablePolymorphicObject<SparsityCsr, LinOp>;
    friend class Csr<ValueType, IndexType>;
    friend class Dense<ValueType>;
    friend class Fbcsr<ValueType, IndexType>;
    GKO_ASSERT_SUPPORTED_VALUE_AND_INDEX_TYPE;
 
public:
    using EnableLinOp<SparsityCsr>::convert_to;
    using EnableLinOp<SparsityCsr>::move_to;
    using ConvertibleTo<Csr<ValueType, IndexType>>::convert_to;
    using ConvertibleTo<Csr<ValueType, IndexType>>::move_to;
    using ConvertibleTo<Dense<ValueType>>::convert_to;
    using ConvertibleTo<Dense<ValueType>>::move_to;
    using ReadableFromMatrixData<ValueType, IndexType>::read;
 
    using value_type = ValueType;
    using index_type = IndexType;
    using transposed_type = SparsityCsr<IndexType, ValueType>;
    using mat_data = matrix_data<ValueType, IndexType>;
    using device_mat_data = device_matrix_data<ValueType, IndexType>;
 
    void convert_to(Csr<ValueType, IndexType>* result) const override;
 
    void move_to(Csr<ValueType, IndexType>* result) override;
 
    void convert_to(Dense<ValueType>* result) const override;
 
    void move_to(Dense<ValueType>* result) override;
 
    void read(const mat_data& data) override;
 
    void read(const device_mat_data& data) override;
 
    void read(device_mat_data&& data) override;
 
    void write(mat_data& data) const override;
 
    std::unique_ptr<LinOp> transpose() const override;
 
    std::unique_ptr<LinOp> conj_transpose() const override;

    std::unique_ptr<SparsityCsr> to_adjacency_matrix() const;

    void sort_by_column_index();
 
    /*
     * Tests if all col_idxs are sorted by column index
     *
     * @returns True if all col_idxs are sorted.
     */
    bool is_sorted_by_column_index() const;

    index_type* get_col_idxs() noexcept { return col_idxs_.get_data(); }

    const index_type* get_const_col_idxs() const noexcept
    {
        return col_idxs_.get_const_data();
    }

    index_type* get_row_ptrs() noexcept { return row_ptrs_.get_data(); }

    const index_type* get_const_row_ptrs() const noexcept
    {
        return row_ptrs_.get_const_data();
    }

    value_type* get_value() noexcept { return value_.get_data(); }

    const value_type* get_const_value() const noexcept
    {
        return value_.get_const_data();
    }

    size_type get_num_nonzeros() const noexcept { return col_idxs_.get_size(); }

    static std::unique_ptr<SparsityCsr> create(
        std::shared_ptr<const Executor> exec, const dim<2>& size = dim<2>{},
        size_type num_nonzeros = {});

    static std::unique_ptr<SparsityCsr> create(
        std::shared_ptr<const Executor> exec, const dim<2>& size,
        array<index_type> col_idxs, array<index_type> row_ptrs,
        value_type value = one<ValueType>());

    template <typename ColIndexType, typename RowPtrType>
    GKO_DEPRECATED(
        "explicitly construct the gko::array argument instead of passing "
        "initializer lists")
    static std::unique_ptr<SparsityCsr> create(
        std::shared_ptr<const Executor> exec, const dim<2>& size,
        std::initializer_list<ColIndexType> col_idxs,
        std::initializer_list<RowPtrType> row_ptrs,
        value_type value = one<ValueType>())
    {
        return create(exec, size, array<index_type>{exec, std::move(col_idxs)},
                      array<index_type>{exec, std::move(row_ptrs)}, value);
    }

    static std::unique_ptr<SparsityCsr> create(
        std::shared_ptr<const Executor> exec,
        std::shared_ptr<const LinOp> matrix);

    static std::unique_ptr<const SparsityCsr> create_const(
        std::shared_ptr<const Executor> exec, const dim<2>& size,
        gko::detail::const_array_view<IndexType>&& col_idxs,
        gko::detail::const_array_view<IndexType>&& row_ptrs,
        ValueType value = one<ValueType>())
    {
        // cast const-ness away, but return a const object afterwards,
        // so we can ensure that no modifications take place.
        return std::unique_ptr<const SparsityCsr>(new SparsityCsr{
            exec, size, gko::detail::array_const_cast(std::move(col_idxs)),
            gko::detail::array_const_cast(std::move(row_ptrs)), value});
    }

    SparsityCsr& operator=(const SparsityCsr&);

    SparsityCsr& operator=(SparsityCsr&&);

    SparsityCsr(const SparsityCsr&);

    SparsityCsr(SparsityCsr&&);
 
protected:
    SparsityCsr(std::shared_ptr<const Executor> exec,
                const dim<2>& size = dim<2>{}, size_type num_nonzeros = {});
 
    SparsityCsr(std::shared_ptr<const Executor> exec, const dim<2>& size,
                array<index_type> col_idxs, array<index_type> row_ptrs,
                value_type value = one<ValueType>());
 
    SparsityCsr(std::shared_ptr<const Executor> exec,
                std::shared_ptr<const LinOp> 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:
    array<index_type> col_idxs_;
    array<index_type> row_ptrs_;
    array<value_type> value_;
};
 
 
}  // namespace matrix
}  // namespace gko
 
 
#endif  // GKO_PUBLIC_CORE_MATRIX_SPARSITY_CSR_HPP_