node/zeroconf.cpp

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/*****************************************************************************
 ** Includes
 *****************************************************************************/

#include <boost/function.hpp>

#include <ros/ros.h>
#include <zeroconf_msgs/AddListener.h>
#include <zeroconf_msgs/RemoveListener.h>
#include <zeroconf_msgs/AddService.h>
#include <zeroconf_msgs/ListDiscoveredServices.h>
#include <zeroconf_msgs/ListPublishedServices.h>

#include "../../include/zeroconf_avahi/zeroconf.hpp"

/*****************************************************************************
 ** Namespaces
 *****************************************************************************/

using namespace zeroconf_avahi;
using namespace zeroconf_msgs;

/*****************************************************************************
 ** Interface
 *****************************************************************************/

class ZeroconfNode
{

private:
  typedef boost::function<void(zeroconf_msgs::DiscoveredService)> connection_signal_cb;

public:
  /*********************
   ** Checks
   **********************/
  void init(ros::NodeHandle &nh)
  {
    if (!zeroconf.is_alive()) {
      ROS_WARN_STREAM("Zeroconf: aborting node initialisation, avahi client is not alive.");
      return;
    }
    /*********************
     ** Ros Comms
     **********************/
    server_add_listener = nh.advertiseService("add_listener", &ZeroconfNode::add_listener, this);
    server_remove_listener = nh.advertiseService("remove_listener", &ZeroconfNode::remove_listener, this);
    server_add_service = nh.advertiseService("add_service", &ZeroconfNode::add_service, this);
    server_remove_service = nh.advertiseService("remove_service", &ZeroconfNode::remove_service, this);
    server_list_discovered_services = nh.advertiseService("list_discovered_services",
                                                          &ZeroconfNode::list_discovered_services, this);
    server_list_published_services = nh.advertiseService("list_published_services",
                                                         &ZeroconfNode::list_published_services, this);
    pub_new_connections = nh.advertise<DiscoveredService>("new_connections", 10);
    pub_lost_connections = nh.advertise<DiscoveredService>("lost_connections", 10);

    /*********************
     ** Signals
     **********************/
    // The callback functions use the publishers, so they must come after.
    connection_signal_cb new_connection_signal = std::bind1st(std::mem_fun(&ZeroconfNode::new_connections), this);
    connection_signal_cb old_connection_signal = std::bind1st(std::mem_fun(&ZeroconfNode::lost_connections), this);
    zeroconf.connect_signal_callbacks(new_connection_signal, old_connection_signal);

    /*********************
     ** Parameters
     **********************/
    ros::NodeHandle local_nh("~");
    // listeners
    XmlRpc::XmlRpcValue value;
    XmlRpc::XmlRpcValue::iterator iter;
    if (local_nh.getParam("listeners", value))
    {
      if (value.getType() != XmlRpc::XmlRpcValue::TypeArray)
      {
        ROS_ERROR_STREAM("Zeroconf: param variable 'listeners' has malformed type, should be of type array");
      }
      else
      {
        for (int i = 0; i < value.size(); ++i)
        {
          zeroconf.add_listener(value[i]);
        }
      }
    }
    // services
    XmlRpc::XmlRpcValue value_services;
    if (local_nh.getParam("services", value_services))
    {
      if (value_services.getType() != XmlRpc::XmlRpcValue::TypeArray)
      {
        ROS_ERROR_STREAM("Zeroconf: param variable 'services' has malformed type, should be of type array");
      }
      else
      {
        for (int i = 0; i < value_services.size(); ++i)
        {
          XmlRpc::XmlRpcValue value_service = value_services[i];
          if (value_service.getType() != XmlRpc::XmlRpcValue::TypeStruct)
          {
            ROS_ERROR_STREAM(
                "Zeroconf: " << i << "th element of param variable 'services' has malformed type, should be of type struct");
            break;
          }
          zeroconf_msgs::PublishedService service;
          XmlRpc::XmlRpcValue value_name = value_service["name"];
          if (value_name.getType() != XmlRpc::XmlRpcValue::TypeString)
          {
            ROS_ERROR_STREAM("Zeroconf: services[" << i << "]['name'] has malformed type, should be of type string");
            break;
          }
          service.name = std::string(value_name);
          if (service.name == "Ros Master")
          {
            // add some special ros magic to easily identify master's.
            service.name = service.name + " (" + ros::master::getHost() + ")";
          }
          XmlRpc::XmlRpcValue value_type = value_service["type"];
          if (value_type.getType() != XmlRpc::XmlRpcValue::TypeString)
          {
            ROS_ERROR_STREAM("Zeroconf: services[" << i << "]['type'] has malformed type, should be of type string");
            break;
          }
          service.type = std::string(value_type);
          XmlRpc::XmlRpcValue value_domain = value_service["domain"];
          if (value_domain.getType() != XmlRpc::XmlRpcValue::TypeString)
          {
            ROS_ERROR_STREAM("Zeroconf: services[" << i << "]['domain'] has malformed type, should be of type string");
            break;
          }
          service.domain = std::string(value_domain);
          XmlRpc::XmlRpcValue value_port = value_service["port"];
          if (value_port.getType() == XmlRpc::XmlRpcValue::TypeInvalid)
          {
            service.port = ros::master::getPort();
            // wasn't set, so default to ros master's port
            ROS_WARN_STREAM(
                "Zeroconf: services[" << service.name << "]['port'] wasn't set, default to ros master's port [" << service.port << "]");
          }
          else if (value_port.getType() != XmlRpc::XmlRpcValue::TypeInt)
          {
            ROS_ERROR_STREAM(
                "Zeroconf: services[" << service.name << "]['port'] has malformed type, should be of type int");
            break;
          }
          else
          {
            service.port = value_port;
          }
          XmlRpc::XmlRpcValue value_description = value_service["description"];
          if (value_description.getType() != XmlRpc::XmlRpcValue::TypeString)
          {
            service.description = "";
          }
          else
          {
            service.description = std::string(value_description);
          }
          zeroconf.add_service(service);
        }
      }
    }
  }

private:
  bool add_listener(AddListener::Request &request, AddListener::Response &response)
  {
    ROS_DEBUG_STREAM("Zeroconf: serving an add_listener call... [" << request.service_type << "]");
    response.result = zeroconf.add_listener(request.service_type);
    return true;
  }
  bool remove_listener(RemoveListener::Request &request, RemoveListener::Response &response)
  {
    ROS_DEBUG_STREAM("Zeroconf: serving a remove_listener call... [" << request.service_type << "]");
    response.result = zeroconf.remove_listener(request.service_type);
    return true;
  }
  bool add_service(AddService::Request &request, AddService::Response &response)
  {
    response.result = zeroconf.add_service(request.service);
    return true;
  }
  bool remove_service(AddService::Request &request, AddService::Response &response)
  {
    response.result = zeroconf.remove_service(request.service);
    return true;
  }
  bool list_discovered_services(ListDiscoveredServices::Request &request, ListDiscoveredServices::Response &response)
  {
    ROS_DEBUG_STREAM("Zeroconf: serving a list_discovered_services call... [" << request.service_type << "]");
    zeroconf.list_discovered_services(request.service_type, response.services);
    return true;
  }
  bool list_published_services(ListPublishedServices::Request &request, ListPublishedServices::Response &response)
  {
    zeroconf.list_published_services(request.service_type, response.services);
    return true;
  }
  void new_connections(DiscoveredService service)
  {
    pub_new_connections.publish(service);
  }
  void lost_connections(DiscoveredService service)
  {
    pub_lost_connections.publish(service);
  }

  Zeroconf zeroconf;
  ros::ServiceServer server_add_listener, server_remove_listener, server_add_service, server_remove_service;
  ros::ServiceServer server_list_discovered_services, server_list_published_services;
  ros::Publisher pub_new_connections, pub_lost_connections;
};

/*****************************************************************************
 ** Main
 *****************************************************************************/

int main(int argc, char **argv)
{

  ros::init(argc, argv, "zeroconf");
  ros::NodeHandle nh;
  ZeroconfNode zeroconf_node;
  zeroconf_node.init(nh);
  ros::spin();
  return 0;
}