artis-star/src/artis-star/kernel/qss/Derivative.hpp

/**
 * @file kernel/qss/Derivative.hpp
 * @author The ARTIS Development Team
 * See the AUTHORS or Authors.txt file
 */

/*
 * ARTIS - the multimodeling and simulation environment
 * This file is a part of the ARTIS environment
 *
 * Copyright (C) 2013-2019 ULCO http://www.univ-littoral.fr
 *
 * 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/>.
 */

#ifndef QSS_DERIVATIVE
#define QSS_DERIVATIVE

#include <artis-star/kernel/pdevs/Dynamics.hpp>
#include <artis-star/kernel/qss/Data.hpp>

namespace artis {
    namespace qss {

        template<class Time, class Dyn, class Parameters = common::NoParameters>
        class Derivative : public artis::pdevs::Dynamics<Time, Dyn, Parameters> {
            typedef enum {
                INIT = 0, WAIT, RESPONSE
            } State;

        public:
            enum inputs {
                RESET = 0, IN
            };

            enum outputs {
                OUT = 0
            };

            enum states {
                STATE = 0, INPUT_NUMBER, OUTPUT_VALUE, LAST_OUTPUT
            };

            typedef Derivative<Time, Dyn, Parameters> type;

            Derivative(const std::string& name, const artis::pdevs::Context<Time, Dyn, Parameters>& context)
                    :
                    artis::pdevs::Dynamics<Time, Dyn, Parameters>(name, context),
                    _external_number(0), _internal_number(0)
            {
                DECLARE_STATES(int,
                        ((STATE, &type::_state)));
                DECLARE_STATES(unsigned int,
                        ((INPUT_NUMBER, &type::_input_number)));
                DECLARE_STATES(double,
                        ((OUTPUT_VALUE, &type::_output_value),
                                (LAST_OUTPUT, &type::_output_value)));

                this->input_ports({{RESET, "reset"},
                                   {IN,    "in"}});
                this->output_port({OUT, "out"});
            }

            virtual ~Derivative() { }

            int external(const std::string& name, double Dyn::* var)
            {
                ++_external_number;
                this->state_(LAST_OUTPUT + _external_number + 1, name, var);
                this->input_port({IN + _external_number, name});
                return IN + _external_number;
            }

            void internal(const std::string& name, double Dyn::* var)
            {
                assert(_internal_number == 0);

                ++_internal_number;
                this->state_(LAST_OUTPUT + 1, name, var);
            }

            virtual double compute() const = 0;

            virtual void dconf(const typename Time::type& t, typename Time::type e,
                    const common::Bag<Time>& bag)
            {
                dint(t);
                dext(t, e, bag);
            }

            virtual void dint(const typename Time::type& /* time */)
            {
                if (_state == RESPONSE) {
                    _last_output = _output_value;
                }
                _state = WAIT;
            }

            virtual void dext(const typename Time::type& t, typename Time::type e,
                    const common::Bag<Time>& bag)
            {
                std::for_each(bag.begin(), bag.end(),
                        [this, t, e](const common::ExternalEvent<Time>& event) {
                            if (event.on_port(RESET)) {
                                if (_input_number == 0) {
                                    _output_value = compute();
                                    _state = RESPONSE;
                                } else {
                                    _state = INIT;
                                }
                            } else {
                                IntegratorData data;

                                event.data()(data);
                                this->get((event.port_index() - 1) + LAST_OUTPUT + 1).put(
                                        dynamic_cast<Dyn*>(this),
                                        data.value);
                                switch (_state) {
                                case INIT:
                                    if (_input_number
                                            == this->state_number() - (LAST_OUTPUT + 1)) {
                                        _output_value = compute();
                                        _state = RESPONSE;
                                    }
                                    break;
                                case WAIT:
                                case RESPONSE:
                                    double value = compute();

                                    if (value != _last_output) {
                                        _output_value = value;
                                        _state = RESPONSE;
                                    } else {
                                        _state = WAIT;
                                    }
                                }
                            }
                        });
            }

            virtual void start(const typename Time::type& /* time */)
            {
                _input_number = this->input_port_number() - 1;
                if (_input_number == 0) {
                    _output_value = compute();
                    _state = RESPONSE;
                } else {
                    _state = INIT;
                }
            }

            virtual typename Time::type ta(const typename Time::type& /* time */)
            {
                switch (_state) {
                case INIT:
                    return Time::infinity;
                case WAIT:
                    return Time::infinity;
                case RESPONSE:
                    return 0;
                }
                return Time::infinity;
            }

            virtual common::Bag<Time> lambda(const typename Time::type& /* time */) const
            {
                common::Bag<Time> msgs;

                switch (_state) {
                case INIT:
                    break;
                case WAIT:
                    break;
                case RESPONSE:
                    const DerivativeData data = {_output_value};

                    msgs.push_back(common::ExternalEvent<Time>(OUT, data));
                }
                return msgs;
            }

            virtual common::Value observe(const typename Time::type& /* t */,
                    unsigned int /* index */) const
            {
                return common::Value();
            }

        private:
            unsigned int _external_number;
            unsigned int _internal_number;

            // state
            int _state;
            unsigned int _input_number;
            double _output_value;
            double _last_output;
        };

    }
}

#endif