RequestServiceTimer.h

// RequestServiceTimer.h
 
// This file is part of bes, A C++ back-end server implementation framework
// for the OPeNDAP Data Access Protocol.
 
// Copyright (c) 2022 OPeNDAP, Inc
// Authors:
//      ndp         Nathan Potter <ndp@opendap.org>
//      dan         Dan Holloway  <dholloway@opendap.org>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//
// You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
#ifndef I_RequestServiceTimer_h
#define I_RequestServiceTimer_h 1
 
#include <map>
#include <string>
#include <mutex>
#include <chrono>
 
 
//#include "BESObj.h"
 
class RequestServiceTimer {
private:
    static RequestServiceTimer *d_instance;
    mutable std::recursive_mutex d_rst_lock_mutex;
 
    std::chrono::milliseconds d_bes_timeout{0};
    std::chrono::steady_clock::time_point start_time{std::chrono::steady_clock::now()};
    bool timeout_enabled{false};
 
    RequestServiceTimer()=default;
    ~RequestServiceTimer()=default;
 
    static void delete_instance();
    static void initialize_instance();
 
public:
 
    static RequestServiceTimer *TheTimer();
 
    void start(std::chrono::milliseconds timeout_ms);
 
    std::chrono::steady_clock::time_point get_start_time() const { return start_time; }
 
    std::chrono::milliseconds elapsed() const;
 
    std::chrono::milliseconds remaining() const;
 
    bool is_timeout_enabled() const { return timeout_enabled; }
 
    bool is_expired() const;
 
    void disable_timeout();
 
    std::string dump(bool pretty=false) const ;
 
    void dump( std::ostream &strm ) const ;
 
    void throw_if_timeout_expired(const std::string &message, const std::string &file, const int line);
 
};
 
#endif // I_RequestServiceTimer_h