scoped_attribute.hpp

/* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * Copyright (C) 2025 Marco Craveiro <marco.craveiro@gmail.com>
 *
 * This program 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.
 *
 * This program 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
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */
#ifndef ORES_LOGGING_SCOPED_ATTRIBUTE_HPP
#define ORES_LOGGING_SCOPED_ATTRIBUTE_HPP
 
#include <string>
#include <optional>
#include <boost/log/core.hpp>
#include <boost/log/attributes/constant.hpp>
#include <boost/log/attributes/attribute_set.hpp>
 
namespace ores::logging {
 
class scoped_attribute {
public:
    using iterator = boost::log::attribute_set::iterator;
 
    explicit scoped_attribute(const std::string& attribute_name) {
        auto result = boost::log::core::get()->add_thread_attribute(
            attribute_name,
            boost::log::attributes::constant<bool>(true));
        if (result.second) {
            iterator_ = result.first;
        }
    }
 
    ~scoped_attribute() {
        if (iterator_.has_value()) {
            boost::log::core::get()->remove_thread_attribute(*iterator_);
        }
    }
 
    // Non-copyable
    scoped_attribute(const scoped_attribute&) = delete;
    scoped_attribute& operator=(const scoped_attribute&) = delete;
 
    // Movable
    scoped_attribute(scoped_attribute&& other) noexcept
        : iterator_(std::move(other.iterator_)) {
        other.iterator_.reset();
    }
 
    scoped_attribute& operator=(scoped_attribute&& other) noexcept {
        if (this != &other) {
            if (iterator_.has_value()) {
                boost::log::core::get()->remove_thread_attribute(*iterator_);
            }
            iterator_ = std::move(other.iterator_);
            other.iterator_.reset();
        }
        return *this;
    }
 
private:
    std::optional<iterator> iterator_;
};
 
}
 
#endif