rail_user_queue_manager.cpp
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00001 //
00002 // Created by pdmitrano on 4/1/15.
00003 //
00004 
00005 #include <rail_user_queue_manager/rail_user_queue_manager.h>
00006 
00007 using namespace std;
00008 using namespace rail;
00009 
00010 int main(int argc, char *argv[])
00011 {
00012   ros::init(argc, argv, "queue_manager");
00013 
00014   //construct a queue
00015   UserQueueManager queue_manager;
00016 
00017   return EXIT_SUCCESS;
00018 }
00019 
00020 UserQueueManager::UserQueueManager() : countdown_(DEFAULT_TRIAL), run_countdown_(false), private_node_("~")
00021 {
00022   //sent out queue
00023   ros::Publisher queue_pub = private_node_.advertise<rail_user_queue_manager::Queue>("queue", 1000);
00024   //add user to queue when someone new visits the website
00025   ros::ServiceServer update_queue_serv = private_node_.advertiseService("update_queue",
00026                                                                         &UserQueueManager::onUpdateQueue, this);
00027 
00028   //loop at the rate of LOOP_RATE, and publish queue
00029   ros::Rate r(LOOP_RATE);
00030 
00031   ROS_INFO("publishing queue...");
00032 
00033   while (ros::ok())
00034   {
00035     // ROS_INFO("countdown: %i\n", countdown_);
00036 
00037     //only run the countdown when the queue isn't empty
00038     if (run_countdown_)
00039     {
00040       //when you countdown has reached 0, reset it and remove the first/current user
00041       if (!countdown_)
00042       {
00043         queue_.pop_front(); //bye bye!
00044         //reset count down to next users trial time
00045         countdown_ = queue_.begin()->second;
00046       }
00047 
00048       //stop counting if the queue is now empty
00049       if (queue_.empty())
00050       {
00051         run_countdown_ = false;
00052       }
00053 
00054       countdown_--;
00055     }
00056 
00057     rail_user_queue_manager::Queue queue_message;
00058 
00059     deque<pair<int, int> >::iterator it = queue_.begin();
00060     int position = 0;
00061     int wait_t;
00062     int t_left;
00063 
00064     //create queue to publish
00065     while (it != queue_.end())
00066     {
00067       pair<int, int> user = *(it++);
00068 
00069       rail_user_queue_manager::UserStatus user_status;
00070       user_status.user_id = user.first;
00071 
00072       //calculate wait time in seconds
00073 
00074       if (position > 0)
00075       {
00076         wait_t = countdown_ + (position - 1) * user.second;
00077       }
00078       else if (position == 0)
00079       {
00080         wait_t = -1;
00081         t_left = countdown_;
00082       }
00083 
00084       ros::Duration wait_time(wait_t);
00085       ros::Duration time_left(t_left);
00086       user_status.wait_time = wait_time;
00087       user_status.time_left = time_left;
00088       queue_message.queue.push_back(user_status);
00089 
00090       position++;
00091 
00092       //ROS_INFO("user %i", user_status.user_id);
00093     }
00094 
00095     //publish the queue message
00096     queue_pub.publish(queue_message);
00097 
00098     ros::spinOnce();
00099     r.sleep();
00100   }
00101 }
00102 
00103 bool UserQueueManager::onUpdateQueue(rail_user_queue_manager::UpdateQueue::Request &req,
00104                                      rail_user_queue_manager::UpdateQueue::Response &res)
00105 {
00106   //get the user Id from the message
00107   int user_id = req.user_id;
00108   int study_time = req.study_time;
00109 
00110   //iterate over the queue, and erase the user that matches the user_id in the message
00111   deque<pair<int, int> >::iterator it = queue_.begin();
00112   while (it != queue_.end())
00113   {
00114     if (user_id == (*it).first)
00115     {
00116       if (!req.enqueue)
00117       {
00118         //when first user leaves reset time for the next user!
00119         if (it == queue_.begin())
00120         {
00121           queue_.pop_front();
00122           int next_study_time = queue_.front().second;
00123           countdown_ = next_study_time ? next_study_time : DEFAULT_TRIAL;
00124         } else
00125         {
00126           queue_.erase(it);
00127         }
00128       }
00129       return true;
00130     }
00131     it++;
00132   }
00133 
00134   if (req.enqueue)
00135   {
00136     study_time = study_time ? study_time : DEFAULT_TRIAL;
00137 
00138     //add that id to the back of the deque
00139     queue_.push_back(pair<int, int>(user_id, study_time));
00140     countdown_ = study_time;
00141 
00142     //start counting down
00143     run_countdown_ = true;
00144   }
00145   return true;
00146 }


rail_user_queue_manager
Author(s): Peter Mitrano
autogenerated on Tue Mar 8 2016 01:01:16