server_direct.cpp

A variant of the server part of a request-response example that accepts incoming connections and does not need an intermediary. Much like the original server, it receives incoming requests, converts the body to uppercase and sends the result back to the indicated reply address. Can be used in conjunction with any of the client alternatives.

/*
 *
 * 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 <proton/container.hpp>
#include <proton/listen_handler.hpp>
#include <proton/listener.hpp>
#include <proton/message.hpp>
#include <proton/message_id.hpp>
#include <proton/messaging_handler.hpp>
#include <proton/sender.hpp>
#include <proton/sender_options.hpp>
#include <proton/source_options.hpp>
#include <proton/tracker.hpp>
 
#include <iostream>
#include <map>
#include <string>
#include <sstream>
#include <cctype>
 
 
class server : public proton::messaging_handler {
  private:
    class listener_ready_handler : public proton::listen_handler {
        void on_open(proton::listener& l) override {
            std::cout << "listening on " << l.port() << std::endl;
        }
    };
 
    typedef std::map<std::string, proton::sender> sender_map;
    listener_ready_handler listen_handler;
    std::string url;
    sender_map senders;
    int address_counter;
 
  public:
    server(const std::string &u) : url(u), address_counter(0) {}
 
    void on_container_start(proton::container &c) override {
        c.listen(url, listen_handler);
    }
 
    std::string to_upper(const std::string &s) {
        std::string uc(s);
        size_t l = uc.size();
 
        for (size_t i=0; i<l; i++)
            uc[i] = static_cast<char>(std::toupper(uc[i]));
 
        return uc;
    }
 
    std::string generate_address() {
        std::ostringstream addr;
        addr << "server" << address_counter++;
 
        return addr.str();
    }
 
    void on_sender_open(proton::sender &sender) override {
        if (sender.source().dynamic()) {
            std::string addr = generate_address();
            sender.open(proton::sender_options().source(proton::source_options().address(addr)));
            senders[addr] = sender;
        }
    }
 
    void on_message(proton::delivery &, proton::message &m) override {
        std::cout << "Received " << m.body() << std::endl;
 
        std::string reply_to = m.reply_to();
        sender_map::iterator it = senders.find(reply_to);
 
        if (it == senders.end()) {
            std::cout << "No link for reply_to: " << reply_to << std::endl;
        } else {
            proton::sender sender = it->second;
            proton::message reply;
 
            reply.to(reply_to);
            reply.body(to_upper(proton::get<std::string>(m.body())));
            reply.correlation_id(m.correlation_id());
 
            sender.send(reply);
        }
    }
};
 
int main(int argc, char **argv) {
    std::string address("amqp://127.0.0.1:5672/examples");
    example::options opts(argc, argv);
 
    opts.add_value(address, 'a', "address", "listen on URL", "URL");
 
    try {
        opts.parse();
 
        server srv(address);
        proton::container(srv).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;
}