scheduled_send_03.cpp

Shows how to use proton::container::schedule to schedule a timed callback in a C++03 compatible way. See scheduled_send.cpp for a more convenient approach using std::function if you have C++11.

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 * to you under the Apache License, Version 2.0 (the
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#include "options.hpp"
 
#include <proton/container.hpp>
#include <proton/connection.hpp>
#include <proton/duration.hpp>
#include <proton/message.hpp>
#include <proton/messaging_handler.hpp>
#include <proton/sender.hpp>
#include <proton/tracker.hpp>
#include <proton/work_queue.hpp>
 
#include <iostream>
 
 
// Send messages at a constant rate one per interval. cancel after a timeout.
// This example uses only C++03 features.
class scheduled_sender : public proton::messaging_handler {
  private:
    std::string url;
    proton::duration interval, timeout;
    proton::work_queue *work_queue;
    bool ready, canceled;
 
  public:
    scheduled_sender(const std::string &s, double d, double t) :
        url(s),
        interval(int(d*proton::duration::SECOND.milliseconds())), // Send interval.
        timeout(int(t*proton::duration::SECOND.milliseconds())), // Cancel after timeout.
        work_queue(0),
        ready(true),            // Ready to send.
        canceled(false)         // Canceled.
    {}
 
    void on_container_start(proton::container &c) override {
        c.open_sender(url);
    }
 
    void on_sender_open(proton::sender & s) override {
        work_queue = &s.work_queue();
 
        work_queue->schedule(timeout, make_work(&scheduled_sender::cancel, this, s));
        work_queue->schedule(interval, make_work(&scheduled_sender::tick, this, s));
    }
 
    void cancel(proton::sender sender) {
        canceled = true;
        sender.connection().close();
    }
 
    void tick(proton::sender sender) {
        if (!canceled) {
            work_queue->schedule(interval, make_work(&scheduled_sender::tick, this, sender)); // Next tick
            if (sender.credit() > 0) // Only send if we have credit
                send(sender);
            else
                ready = true; // Set the ready flag, send as soon as we get credit.
        }
    }
 
    void on_sendable(proton::sender &sender) override {
        if (ready)              // We have been ticked since the last send.
            send(sender);
    }
 
    void send(proton::sender& sender) {
        std::cout << "send" << std::endl;
        sender.send(proton::message("ping"));
        ready = false;
    }
};
 
 
int main(int argc, char **argv) {
    std::string address("127.0.0.1:5672/examples");
    double interval = 1.0;
    double timeout = 5.0;
 
    example::options opts(argc, argv);
 
    opts.add_value(address, 'a', "address", "connect and send to URL", "URL");
    opts.add_value(interval, 'i', "interval", "send a message every INTERVAL seconds", "INTERVAL");
    opts.add_value(timeout, 't', "timeout", "stop after T seconds", "T");
 
    try {
        opts.parse();
        scheduled_sender h(address, interval, timeout);
        proton::container(h).run();
        return 0;
    } catch (const example::bad_option& e) {
        std::cout << opts << std::endl << e.what() << std::endl;
    } catch (const std::exception& e) {
        std::cerr << e.what() << std::endl;
    }
 
    return 1;
}