node_handle.h

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#ifndef ROS_NODE_HANDLE_H_
#define ROS_NODE_HANDLE_H_

#include "../std_msgs/Time.h"
#include "../rosserial_msgs/TopicInfo.h"
#include "../rosserial_msgs/Log.h"
#include "../rosserial_msgs/RequestParam.h"

#define SYNC_SECONDS        5

#define MODE_FIRST_FF       0
#define MODE_SECOND_FF      1
#define MODE_TOPIC_L        2   // waiting for topic id
#define MODE_TOPIC_H        3
#define MODE_SIZE_L         4   // waiting for message size
#define MODE_SIZE_H         5
#define MODE_MESSAGE        6
#define MODE_CHECKSUM       7

#define MSG_TIMEOUT 20  //20 milliseconds to recieve all of message data

#include "node_output.h"

#include "publisher.h"
#include "msg_receiver.h"
#include "subscriber.h"
#include "rosserial_ids.h"
#include "service_server.h"

namespace ros {

  using rosserial_msgs::TopicInfo;

  /* Node Handle */
  template<class Hardware,
           int MAX_SUBSCRIBERS=25,
           int MAX_PUBLISHERS=25,
           int INPUT_SIZE=512,
           int OUTPUT_SIZE=512>
  class NodeHandle_
  {
    protected:
      Hardware hardware_;
      NodeOutput<Hardware, OUTPUT_SIZE> no_;

      /* time used for syncing */
      unsigned long rt_time;

      /* used for computing current time */
      unsigned long sec_offset, nsec_offset;

      unsigned char message_in[INPUT_SIZE];

      Publisher * publishers[MAX_PUBLISHERS];
      MsgReceiver * receivers[MAX_SUBSCRIBERS];

      /*
       * Setup Functions
       */
    public:
      NodeHandle_() : no_(&hardware_) {}
      
      Hardware* getHardware(){
        return &hardware_;
      }

      /* Start serial, initialize buffers */
      void initNode(){
        hardware_.init();
        mode_ = 0;
        bytes_ = 0;
        index_ = 0;
        topic_ = 0;
        total_receivers=0;
      };

    protected:
      //State machine variables for spinOnce
      int mode_;
      int bytes_;
      int topic_;
      int index_;
      int checksum_;

      int total_receivers;

      /* used for syncing the time */
      unsigned long last_sync_time;
      unsigned long last_sync_receive_time;
      unsigned long last_msg_timeout_time;

      bool registerReceiver(MsgReceiver* rcv){
        if (total_receivers >= MAX_SUBSCRIBERS)
          return false;
        receivers[total_receivers] = rcv;
        rcv->id_ = 100+total_receivers;
        total_receivers++;
        return true;
      }

    public:
      /* This function goes in your loop() function, it handles
       *  serial input and callbacks for subscribers.
       */

      virtual void spinOnce(){

        /* restart if timed out */
        unsigned long c_time = hardware_.time();
        if( (c_time - last_sync_receive_time) > (SYNC_SECONDS*2200) ){
            no_.setConfigured(false);
         }
         
        /* reset if message has timed out */
        if ( mode_ != MODE_FIRST_FF){ 
          if (c_time > last_msg_timeout_time){
            mode_ = MODE_FIRST_FF;
          }
        }

        /* while available buffer, read data */
        while( true )
        {
          int data = hardware_.read();
          if( data < 0 )
            break;
          checksum_ += data;
          if( mode_ == MODE_MESSAGE ){        /* message data being recieved */
            message_in[index_++] = data;
            bytes_--;
            if(bytes_ == 0)                   /* is message complete? if so, checksum */
              mode_ = MODE_CHECKSUM;
          }else if( mode_ == MODE_FIRST_FF ){
            if(data == 0xff){
              mode_++;
              last_msg_timeout_time = c_time + MSG_TIMEOUT;
            }
          }else if( mode_ == MODE_SECOND_FF ){
            if(data == 0xff){
              mode_++;
            }else{
              mode_ = MODE_FIRST_FF;
            }
          }else if( mode_ == MODE_TOPIC_L ){  /* bottom half of topic id */
            topic_ = data;
            mode_++;
            checksum_ = data;                 /* first byte included in checksum */
          }else if( mode_ == MODE_TOPIC_H ){  /* top half of topic id */
            topic_ += data<<8;
            mode_++;
          }else if( mode_ == MODE_SIZE_L ){   /* bottom half of message size */
            bytes_ = data;
            index_ = 0;
            mode_++;
          }else if( mode_ == MODE_SIZE_H ){   /* top half of message size */
            bytes_ += data<<8;
            mode_ = MODE_MESSAGE;
            if(bytes_ == 0)
              mode_ = MODE_CHECKSUM;
          }else if( mode_ == MODE_CHECKSUM ){ /* do checksum */
            if( (checksum_%256) == 255){
              if(topic_ == TOPIC_NEGOTIATION){
                requestSyncTime();
                negotiateTopics();
                last_sync_time = c_time;
                last_sync_receive_time = c_time;
              }else if(topic_ == TopicInfo::ID_TIME){
                syncTime(message_in);
              }else if (topic_ == TopicInfo::ID_PARAMETER_REQUEST){
                  req_param_resp.deserialize(message_in);
                  param_recieved= true;
              }else{
                if(receivers[topic_-100])
                  receivers[topic_-100]->receive( message_in );
              }
            }
            mode_ = MODE_FIRST_FF;
          }
        }

        /* occasionally sync time */
        if( no_.configured() && ((c_time-last_sync_time) > (SYNC_SECONDS*500) )){
          requestSyncTime();
          last_sync_time = c_time;
        }
      }

      /* Are we connected to the PC? */
      bool connected() {
        return no_.configured();
      };

      /*
       * Time functions
       */

      void requestSyncTime()
      {
        std_msgs::Time t;
        no_.publish( rosserial_msgs::TopicInfo::ID_TIME, &t);
        rt_time = hardware_.time();
      }

      void syncTime( unsigned char * data )
      {
        std_msgs::Time t;
        unsigned long offset = hardware_.time() - rt_time;

        t.deserialize(data);

        t.data.sec += offset/1000;
        t.data.nsec += (offset%1000)*1000000UL;

        this->setNow(t.data);
        last_sync_receive_time = hardware_.time();
      }

      Time now(){
        unsigned long ms = hardware_.time();
        Time current_time;
        current_time.sec = ms/1000 + sec_offset;
        current_time.nsec = (ms%1000)*1000000UL + nsec_offset;
        normalizeSecNSec(current_time.sec, current_time.nsec);
        return current_time;
      }

      void setNow( Time & new_now )
      {
        unsigned long ms = hardware_.time();
        sec_offset = new_now.sec - ms/1000 - 1;
        nsec_offset = new_now.nsec - (ms%1000)*1000000UL + 1000000000UL;
        normalizeSecNSec(sec_offset, nsec_offset);
      }

      /*
       * Registration 
       */

      bool advertise(Publisher & p)
      {
        int i;
        for(i = 0; i < MAX_PUBLISHERS; i++)
        {
          if(publishers[i] == 0) // empty slot
          {
            publishers[i] = &p;
            p.id_ = i+100+MAX_SUBSCRIBERS;
            p.no_ = &this->no_;
            return true;
          }
        }
        return false;
      }

      /* Register a subscriber with the node */
      template<typename MsgT>
        bool subscribe(Subscriber< MsgT> &s){
        return registerReceiver((MsgReceiver*) &s);
      }

      template<typename SrvReq, typename SrvResp>
      bool advertiseService(ServiceServer<SrvReq,SrvResp>& srv){
        srv.no_ = &no_;
        return registerReceiver((MsgReceiver*) &srv);
      }

      void negotiateTopics()
      {
        no_.setConfigured(true);

        rosserial_msgs::TopicInfo ti;
        int i;
        for(i = 0; i < MAX_PUBLISHERS; i++)
        {
          if(publishers[i] != 0) // non-empty slot
          {
            ti.topic_id = publishers[i]->id_;
            ti.topic_name = (char *) publishers[i]->topic_;
            ti.message_type = (char *) publishers[i]->msg_->getType();
            no_.publish( TOPIC_PUBLISHERS, &ti );
          }
        }
        for(i = 0; i < MAX_SUBSCRIBERS; i++)
        {
          if(receivers[i] != 0) // non-empty slot
          {
            ti.topic_id = receivers[i]->id_;
            ti.topic_name = (char *) receivers[i]->topic_;
            ti.message_type = (char *) receivers[i]->getMsgType();
            no_.publish( TOPIC_SUBSCRIBERS, &ti );
          }
        }
      }

      /*
       * Logging
       */

    private:
      void log(char byte, const char * msg){
        rosserial_msgs::Log l;
        l.level= byte;
        l.msg = (char*)msg;
        this->no_.publish(rosserial_msgs::TopicInfo::ID_LOG, &l);
      }

    public:
      void logdebug(const char* msg){
        log(rosserial_msgs::Log::DEBUG, msg);
      }
      void loginfo(const char * msg){
        log(rosserial_msgs::Log::INFO, msg);
      }
      void logwarn(const char *msg){
        log(rosserial_msgs::Log::WARN, msg);
      }
      void logerror(const char*msg){
        log(rosserial_msgs::Log::ERROR, msg);
      }
      void logfatal(const char*msg){
        log(rosserial_msgs::Log::FATAL, msg);
      }


      /*
       * Retrieve Parameters
       */

    private:
      bool param_recieved;
      rosserial_msgs::RequestParamResponse req_param_resp;

      bool requestParam(const char * name, int time_out =  1000){
        param_recieved = false;
        rosserial_msgs::RequestParamRequest req;
        req.name  = (char*)name;
        no_.publish(TopicInfo::ID_PARAMETER_REQUEST, &req);
        int end_time = hardware_.time();
        while(!param_recieved ){
          spinOnce();
          if (end_time > hardware_.time()) return false;
        }
        return true;
      }

    public:
      bool getParam(const char* name, int* param, int length =1){
        if (requestParam(name) ){
          if (length == req_param_resp.ints_length){
            //copy it over
            for(int i=0; i<length; i++)
              param[i] = req_param_resp.ints[i];
            return true;
          }
        }
        return false;
      }
      bool getParam(const char* name, float* param, int length=1){
        if (requestParam(name) ){
          if (length == req_param_resp.floats_length){
            //copy it over
            for(int i=0; i<length; i++) 
              param[i] = req_param_resp.floats[i];
            return true;
          }
        }
        return false;
      }
      bool getParam(const char* name, char** param, int length=1){
        if (requestParam(name) ){
          if (length == req_param_resp.strings_length){
            //copy it over
            for(int i=0; i<length; i++)
              strcpy(param[i],req_param_resp.strings[i]);
            return true;
          }
        }
        return false;
      }  
  };

}

#endif