heartbeat.hpp

// A context extension for printing data from a feed using a heartbeat timer.
// Copyright 2020 Christian Kauten
//
// Author: Christian Kauten (kautenja@auburn.edu)
//
// 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 DATA_FEED_EXTENSIONS_HEARTBEAT_HPP
#define DATA_FEED_EXTENSIONS_HEARTBEAT_HPP
 
#include "data_feed/receiver.hpp"
#include <asio.hpp>
#include <cstdint>
#include <chrono>
#include <ostream>
 
namespace DataFeed {
 
namespace Extensions {
 
template<typename T>
class Heartbeat {
 private:
    Receiver<T>& receiver;
    asio::steady_timer timer;
    uint16_t time;
    std::ostream& stream;
 
    void start() {
        // clear the terminal
        stream << "\033[2J" << "\033[1;1H" << std::endl;
        // print the top of book information
        stream << receiver.get_book() << std::endl;
        // set a timer to start the strategy again
        timer.expires_after(std::chrono::milliseconds(time));
        timer.async_wait([this](const std::error_code& error) {
            if (error) throw error;
            start();
        });
    }
 
 public:
    Heartbeat(
        asio::io_context& context,
        Receiver<T>& receiver_,
        uint16_t time_ = 300,
        std::ostream& stream_ = std::cout
    ) : receiver(receiver_), timer(context), time(time_), stream(stream_) {
        start();
    }
};
 
}  // namespace Extensions
 
}  // namespace DataFeed
 
#endif  // DATA_FEED_EXTENSIONS_HEARTBEAT_HPP