gvstartup.h

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//
// Copyright (C) 2017 Graeme Walker
// 
// 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, see <http://www.gnu.org/licenses/>.
// ===
///
/// \file gvstartup.h
///

#ifndef GV_STARTUP__H
#define GV_STARTUP__H

#include "gdef.h"
#include "glogoutput.h"
#include "gpidfile.h"
#include "ggetopt.h"

namespace Gv
{
    class Startup ;
}

/// \class Gv::Startup
/// A handy synthesis of G::LogOutput, G::GetOpt, G::Root, G::Daemon and 
/// G::PidFile, used to initialise a server process.
/// 
class Gv::Startup
{
public:
    Startup( const G::GetOpt & , const std::string & args_help , bool argc_ok , 
        const std::string & extra_help = std::string() ) ;
            ///< Constructor, typically used very early in main(). Parses the
            ///< command-line and processes "--help" and "--version". Assumes
            ///< there are options for "daemon", "user", "verbose", "debug",
            ///< "log-time", "syslog" and "pid-file". Throws Gv::Exit for
            ///< an immediate exit.

    void start() ;
        ///< Called just before the event loop. This should be used after all 
        ///< non-event-driven initialisation has completed. The process forks and exits 
        ///< the parent, if required.

    void report( const std::string & prefix , std::exception & e ) ;
        ///< Reports an error if start()ed and "daemon" or "syslog" are in effect.
        ///< This is useful for errors that would otherwise only go to stderr
        ///< since stderr might be closed.

    void report( const std::string & prefix , const std::string & what ) ;
        ///< Reports an error if start()ed and "daemon" or "syslog" are in effect.

    static void sanitise( int argc , char * argv [] ) ;
        ///< Removes sensitive information from the command-line, if possible.

private:
    Startup( const Startup & ) ;
    void operator=( const Startup & ) ;
    static void onSignal( int ) ;

private:
    bool m_debug ;
    G::LogOutput m_log_output ;
    bool m_daemon ;
    bool m_syslog ;
    bool m_verbose ;
    G::PidFile m_pid_file ;
    std::string m_user ;
    bool m_started ;
} ;

#endif