Qpid Proton C++ API  0.18.1
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.

/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
#include "options.hpp"
#include <iostream>
#include "fake_cpp11.hpp"
// 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.
{}
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);
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;
}