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// Copyright (c) 2019 Egor Tensin <Egor.Tensin@gmail.com>
// This file is part of the "math-server" project.
// For details, see https://github.com/egor-tensin/math-server.
// Distributed under the MIT License.
#pragma once
#include <boost/filesystem.hpp>
#include <boost/program_options.hpp>
#include <cstddef>
#include <exception>
#include <iostream>
#include <string>
#include <thread>
#include <vector>
namespace math::server {
struct Settings {
static constexpr unsigned short DEFAULT_PORT = 18000;
static std::size_t default_threads() { return std::thread::hardware_concurrency(); }
unsigned short m_port;
std::size_t m_threads;
bool exit_with_usage() const { return m_vm.count("help"); }
boost::program_options::variables_map m_vm;
};
class SettingsParser {
public:
explicit SettingsParser(const std::string& argv0) : m_prog_name{extract_filename(argv0)} {
m_visible.add_options()("help,h", "show this message and exit");
m_visible.add_options()("port,p",
boost::program_options::value(&m_settings.m_port)
->default_value(Settings::DEFAULT_PORT),
"server port number");
m_visible.add_options()("threads,n",
boost::program_options::value(&m_settings.m_threads)
->default_value(Settings::default_threads()),
"number of threads");
}
static const char* get_short_description() { return "[-h|--help] [-p|--port] [-n|--threads]"; }
Settings parse(int argc, char* argv[]) {
boost::program_options::store(
boost::program_options::command_line_parser{argc, argv}.options(m_visible).run(),
m_settings.m_vm);
if (m_settings.exit_with_usage()) {
return m_settings;
}
boost::program_options::notify(m_settings.m_vm);
return m_settings;
}
void usage() const { std::cout << *this; }
void usage_error(const std::exception& e) const {
std::cerr << "usage error: " << e.what() << '\n';
std::cerr << *this;
}
private:
static std::string extract_filename(const std::string& path) {
return boost::filesystem::path{path}.filename().string();
}
const std::string m_prog_name;
boost::program_options::options_description m_visible;
Settings m_settings;
friend std::ostream& operator<<(std::ostream& os, const SettingsParser& parser) {
os << "usage: " << parser.m_prog_name << ' ' << get_short_description() << '\n';
os << parser.m_visible;
return os;
}
};
} // namespace math::server
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