Program Listing for File row.hpp

↰ Return to documentation for file (cif++/row.hpp)

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2022 NKI/AVL, Netherlands Cancer Institute
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "cif++/item.hpp"

#include <array>
#include <cstddef>
#include <cstdint>
#include <initializer_list>
#include <string>
#include <string_view>
#include <tuple>
#include <type_traits>
#include <utility>
#include <vector>


namespace cif
{

class category;

namespace cql
{
    struct connection_impl;
}

namespace detail
{
    template <typename... C>
    struct get_row_result;
}

// --------------------------------------------------------------------

class row : public std::vector<item_value>
{
  public:
    row() = default;

  private:
    item_value *get(uint16_t ix)
    {
        if (ix >= size())
            resize(ix + 1);
        return &data()[ix];
    }

    [[nodiscard]] const item_value *get(uint16_t ix) const
    {
        return ix < size() ? &data()[ix] : nullptr;
    }

    void set(uint16_t ix, item_value v)
    {
        if (ix >= size())
            resize(ix + 1);
        operator[](ix) = std::move(v);
    }

    friend class category;
    friend class category_index;

    template <bool, typename...>
    friend class iterator_impl_base;

    row *m_next = nullptr;
};

// --------------------------------------------------------------------

class row_handle
{
  public:
    template <bool>
    friend struct item_handle_base;
    friend class category;
    friend class category_index;
    friend class row_initializer;
    friend class const_row_handle;

    template <bool, typename...>
    friend class iterator_impl_base;

    row_handle() = default;
    virtual ~row_handle() = default;

    row_handle(const row_handle &) = default;
    row_handle(row_handle &&) = default;
    row_handle &operator=(const row_handle &) = default;
    row_handle &operator=(row_handle &&) = default;


    row_handle(category &cat, row &r)
        : m_category(&cat)
        , m_row(&r)
    {
    }

    [[nodiscard]] category &get_category() const
    {
        return *m_category;
    }

    [[nodiscard]] int64_t row_id() const
    {
        return reinterpret_cast<int64_t>(m_row);
    }

    [[nodiscard]] bool empty() const
    {
        return m_category == nullptr or m_row == nullptr;
    }

    explicit operator bool() const
    {
        return not empty();
    }

    [[nodiscard]] size_t size() const { return m_row->size(); }

    item_handle operator[](uint16_t item_ix)
    {
        return { *m_category, *m_row, item_ix };
    }

    const item_handle operator[](uint16_t item_ix) const
    {
        return { *m_category, *m_row, item_ix };
    }

    item_handle operator[](std::string_view item_name)
    {
        return { *m_category, *m_row, add_item(item_name) };
    }

    const item_handle operator[](std::string_view item_name) const
    {
        return { *m_category, *m_row, get_item_ix(item_name) };
    }

    void assign(const std::vector<item> &values, bool updateLinked = true)
    {
        for (auto &value : values)
            assign(value, updateLinked);
    }


    void assign(std::string_view name, item_value value, bool updateLinked, bool validate = true)
    {
        assign(add_item(name), std::move(value), updateLinked, validate);
    }


    void assign(uint16_t item, item_value value, bool updateLinked, bool validate = true);

    template <typename... C>
    [[nodiscard]] auto get(C... items) const
    {
        return detail::get_row_result<C...>(*this, { get_item_ix(items)... });
    }

    template <typename... Ts, typename... C>
    std::tuple<Ts...> get(C... items) const
        requires(sizeof...(Ts) == sizeof...(C) and sizeof...(C) != 1)
    {
        return detail::get_row_result<Ts...>(*this, { get_item_ix(items)... });
    }

    template <typename T>
    [[nodiscard]] T get(std::string_view item) const
    {
        return operator[](get_item_ix(item)).template get<T>();
    }

    bool operator==(const row_handle &rhs) const { return m_category == rhs.m_category and m_row == rhs.m_row; }

    bool operator!=(const row_handle &rhs) const { return m_category != rhs.m_category or m_row != rhs.m_row; }

  protected:
    [[nodiscard]] uint16_t get_item_ix(std::string_view name) const;

    [[nodiscard]] std::string_view get_item_name(uint16_t ix) const;

    friend cql::connection_impl;

    [[nodiscard]] auto get_row() const
    {
        return m_row;
    }

    category *m_category = nullptr;
    row *m_row = nullptr;

  private:
    uint16_t add_item(std::string_view name);

    void assign(const item &i, bool updateLinked)
    {
        assign(i.name(), i.value(), updateLinked);
    }

};


class const_row_handle
{
  public:
    template <bool>
    friend struct item_handle_base;
    friend class category;
    friend class category_index;
    friend class row_initializer;

    template <bool, typename...>
    friend class iterator_impl_base;

    const_row_handle() = default;
    virtual ~const_row_handle() = default;

    const_row_handle(const const_row_handle &) = default;
    const_row_handle(const_row_handle &&) = default;
    const_row_handle &operator=(const const_row_handle &) = default;
    const_row_handle &operator=(const_row_handle &&) = default;

    const_row_handle(row_handle rh)
        : m_category(rh.m_category)
        , m_row(rh.m_row)
    {
    }


    const_row_handle(const category &cat, const row &r)
        : m_category(&cat)
        , m_row(&r)
    {
    }

    [[nodiscard]] const category &get_category() const
    {
        return *m_category;
    }

    [[nodiscard]] int64_t row_id() const
    {
        return reinterpret_cast<int64_t>(m_row);
    }

    [[nodiscard]] bool empty() const
    {
        return m_category == nullptr or m_row == nullptr;
    }

    explicit operator bool() const
    {
        return not empty();
    }

    [[nodiscard]] size_t size() const { return m_row->size(); }

    const item_handle operator[](uint16_t item_ix) const
    {
        return { *m_category, *m_row, item_ix };
    }

    const item_handle operator[](std::string_view item_name) const
    {
        return operator[](get_item_ix(item_name));
    }

    template <typename... C>
    [[nodiscard]] auto get(C... items) const
    {
        return detail::get_row_result<C...>(*this, { get_item_ix(items)... });
    }

    template <typename... Ts, typename... C>
    std::tuple<Ts...> get(C... items) const
        requires(sizeof...(Ts) == sizeof...(C) and sizeof...(C) != 1)
    {
        return detail::get_row_result<Ts...>(*this, { get_item_ix(items)... });
    }

    template <typename T>
    [[nodiscard]] T get(std::string_view item) const
    {
        return operator[](get_item_ix(item)).template get<T>();
    }

    // bool operator==(const const_row_handle &rhs) const { return m_category == rhs.m_category and m_row == rhs.m_row; }
    friend bool operator==(const_row_handle a, const_row_handle b)
    {
        return a.m_category == b.m_category and a.m_row == b.m_row;
    }

    bool operator!=(const const_row_handle &rhs) const { return m_category != rhs.m_category or m_row != rhs.m_row; }

  protected:
    [[nodiscard]] uint16_t get_item_ix(std::string_view name) const;

    [[nodiscard]] std::string_view get_item_name(uint16_t ix) const;

    friend cql::connection_impl;

    [[nodiscard]] auto get_row() const
    {
        return m_row;
    }

    const category *m_category = nullptr;
    const row *m_row = nullptr;
};

namespace detail
{

    template <typename... C>
    struct get_row_result
    {
        static constexpr std::size_t N = sizeof...(C);

        get_row_result(const_row_handle r, std::array<uint16_t, N> &&items)
            : m_row(std::move(r))
            , m_items(std::move(items))
        {
        }

        const item_handle operator[](uint16_t ix) const
        {
            return m_row[m_items[ix]];
        }

        template <typename... Ts>
        operator std::tuple<Ts...>() const
            requires(N == sizeof...(Ts))
        {
            return get<Ts...>(std::index_sequence_for<Ts...>{});
        }

        template <typename... Ts, std::size_t... Is>
        [[nodiscard]] std::tuple<Ts...> get(std::index_sequence<Is...>) const
        {
            return std::tuple<Ts...>{ m_row[m_items[Is]].template get<Ts>()... };
        }

        const_row_handle m_row;
        std::array<uint16_t, N> m_items;
    };

    // we want to be able to tie some variables to a get_row_result, for this we use tiewraps
    template <typename... Ts>
    struct tie_wrap
    {
        tie_wrap(Ts... args)
            : m_value(args...)
        {
        }

        template <typename RR>
        void operator=(const RR &&rr)
        {
            // get_row_result will do the conversion, but only if the types
            // are compatible. That means the number of parameters to the get()
            // of the row should be equal to the number of items in the tuple
            // you are trying to tie.

            using RType = std::tuple<std::remove_reference_t<Ts>...>;

            m_value = static_cast<RType>(rr);
        }

        std::tuple<Ts...> m_value;
    };


} // namespace detail

template <typename... Ts>
auto tie(Ts &...v)
{
    return detail::tie_wrap<Ts &...>(std::forward<Ts &>(v)...);
}

// --------------------------------------------------------------------

class row_initializer : public std::vector<item>
{
  public:
    friend class category;

    row_initializer() = default;
    row_initializer(const row_initializer &) = default;
    row_initializer(row_initializer &&) = default;
    row_initializer &operator=(const row_initializer &) = default;
    row_initializer &operator=(row_initializer &&) = default;


    row_initializer(std::initializer_list<item> items)
        : std::vector<item>(items)
    {
    }

    template <typename ItemIter>
    row_initializer(ItemIter b, ItemIter e)
        requires(std::is_constructible_v<item, typename ItemIter::value_type>)
        : std::vector<item>(b, e)
    {
    }

    row_initializer(row_handle rh)
        : cif::row_initializer(const_row_handle{ rh })
    {
    }

    row_initializer(const_row_handle rh);

    void set_value(std::string name, item_value value);

    void set_value(const item &i)
    {
        set_value(i.name(), i.value());
    }

    void set_value_if_empty(std::string name, item_value value);

    void set_value_if_empty(const item &i)
    {
        set_value_if_empty(i.name(), i.value());
    }

    auto emplace_back(std::string name, item_value value)
    {
        return std::vector<item>::emplace_back(item(std::forward<std::string>(name), std::forward<item_value>(value)));
    }
};

} // namespace cif