robot/include/asio2/bho/mysql/impl/internal/protocol/null_bitmap_traits.hpp

//
// Copyright (c) 2019-2023 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef BHO_MYSQL_IMPL_INTERNAL_PROTOCOL_NULL_BITMAP_TRAITS_HPP
#define BHO_MYSQL_IMPL_INTERNAL_PROTOCOL_NULL_BITMAP_TRAITS_HPP

#include <asio2/bho/assert.hpp>

#include <cstddef>
#include <cstdint>

namespace bho {
namespace mysql {
namespace detail {

class null_bitmap_traits
{
    std::size_t offset_;
    std::size_t num_fields_;

    constexpr std::size_t byte_pos(std::size_t field_pos) const noexcept { return (field_pos + offset_) / 8; }
    constexpr std::size_t bit_pos(std::size_t field_pos) const noexcept { return (field_pos + offset_) % 8; }

public:
    constexpr null_bitmap_traits(std::size_t offset, std::size_t num_fields) noexcept
        : offset_(offset), num_fields_{num_fields} {};
    constexpr std::size_t offset() const noexcept { return offset_; }
    constexpr std::size_t num_fields() const noexcept { return num_fields_; }

    constexpr std::size_t byte_count() const noexcept { return (num_fields_ + 7 + offset_) / 8; }
    bool is_null(const std::uint8_t* null_bitmap_begin, std::size_t field_pos) const noexcept
    {
        BHO_ASSERT(field_pos < num_fields_);
        return null_bitmap_begin[byte_pos(field_pos)] & (1 << bit_pos(field_pos));
    }
    void set_null(std::uint8_t* null_bitmap_begin, std::size_t field_pos) const noexcept
    {
        BHO_ASSERT(field_pos < num_fields_);
        null_bitmap_begin[byte_pos(field_pos)] |= (1 << bit_pos(field_pos));
    }
};

constexpr std::size_t stmt_execute_null_bitmap_offset = 0;
constexpr std::size_t binary_row_null_bitmap_offset = 2;

}  // namespace detail
}  // namespace mysql
}  // namespace bho

#endif /* INCLUDE_NULL_BITMAP_HPP_ */