text: /*
   * This file is open source software, licensed to you under the terms
   * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
   * distributed with this work for additional information regarding copyright
   * ownership.  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.
   */
  /*
   * Copyright (C) 2014 Cloudius Systems, Ltd.
   */
  
  #include <seastar/core/app-template.hh>
  #include <seastar/core/future-util.hh>
  #include <seastar/core/reactor.hh>
  #include <seastar/net/api.hh>
  
  using namespace seastar;
  using namespace net;
  using namespace std::chrono_literals;
  
  class client {
  private:
      udp_channel _chan;
      uint64_t n_sent {};
      uint64_t n_received {};
      uint64_t n_failed {};
      timer<> _stats_timer;
  public:
      void start(ipv4_addr server_addr) {
          std::cout << "Sending to " << server_addr << std::endl;
  
          _chan = engine().net().make_udp_channel();
  
          _stats_timer.set_callback([this] {
              std::cout << "Out: " << n_sent << " pps, \t";
              std::cout << "Err: " << n_failed << " pps, \t";
              std::cout << "In: " << n_received << " pps" << std::endl;
              n_sent = 0;
              n_received = 0;
              n_failed = 0;
          });
          _stats_timer.arm_periodic(1s);
  
          keep_doing([this, server_addr] {
              return _chan.send(server_addr, "hello!\n")
                  .then_wrapped([this] (auto&& f) {
                      try {
                          f.get();
                          n_sent++;
                      } catch (...) {
                          n_failed++;
                      }
                  });
          });
  
          keep_doing([this] {
              return _chan.receive().then([this] (auto) {
                  n_received++;
              });
          });
      }
  };
  
  namespace bpo = boost::program_options;
  
  int main(int ac, char ** av) {
      client _client;
      app_template app;
      app.add_options()
          ("server", bpo::value<std::string>(), "Server address")
          ;
      return app.run_deprecated(ac, av, [&_client, &app] {
          auto&& config = app.configuration();
          _client.start(config["server"].as<std::string>());
      });
  }
  