File content as of revision 4:684f39d0c346:

/*
 * Software License Agreement (BSD License)
 *
 * Copyright (c) 2011, Willow Garage, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer in the documentation and/or other materials provided
 *    with the distribution.
 *  * Neither the name of Willow Garage, Inc. nor the names of its
 *    contributors may be used to endorse or promote prducts derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#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 "msg.h"

namespace ros {

class NodeHandleBase_ {
public:
    virtual int publish(int16_t id, const Msg* msg)=0;
    virtual int spinOnce()=0;
    virtual bool connected()=0;
};

}

#include "publisher.h"
#include "subscriber.h"
#include "service_server.h"
#include "service_client.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_ : public NodeHandleBase_ {
protected:
    Hardware hardware_;

    /* 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];
    unsigned char message_out[OUTPUT_SIZE];

    Publisher * publishers[MAX_PUBLISHERS];
    Subscriber_ * subscribers[MAX_SUBSCRIBERS];

    /*
     * Setup Functions
     */
public:
    NodeHandle_() : configured_(false) {}

    Hardware* getHardware() {
        return &hardware_;
    }

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

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

    bool configured_;

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

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

    virtual int spinOnce() {

        /* restart if timed out */
        unsigned long c_time = hardware_.time();
        if ( (c_time - last_sync_receive_time) > (SYNC_SECONDS*2200) ) {
            configured_ = 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 )//no data
                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 */
                mode_ = MODE_FIRST_FF;
                if ( (checksum_%256) == 255) {
                    if (topic_ == TopicInfo::ID_PUBLISHER) {
                        requestSyncTime();
                        negotiateTopics();
                        last_sync_time = c_time;
                        last_sync_receive_time = c_time;
                        return -1;
                    } 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 (subscribers[topic_-100])
                            subscribers[topic_-100]->callback( message_in );
                    }
                }
            }
        }

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

        return 0;
    }

    /* Are we connected to the PC? */
    virtual bool connected() {
        return configured_;
    };

    /********************************************************************
     * Time functions
     */

    void requestSyncTime() {
        std_msgs::Time t;
        publish(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);
    }

    /********************************************************************
     * Topic Management
     */

    /* Register a new publisher */
    bool advertise(Publisher & p) {
        for (int i = 0; i < MAX_PUBLISHERS; i++) {
            if (publishers[i] == 0) { // empty slot
                publishers[i] = &p;
                p.id_ = i+100+MAX_SUBSCRIBERS;
                p.nh_ = this;
                return true;
            }
        }
        return false;
    }

    /* Register a new subscriber */
    template<typename MsgT>
    bool subscribe(Subscriber< MsgT> & s) {
        for (int i = 0; i < MAX_SUBSCRIBERS; i++) {
            if (subscribers[i] == 0) { // empty slot
                subscribers[i] = (Subscriber_*) &s;
                s.id_ = i+100;
                return true;
            }
        }
        return false;
    }

    /* Register a new Service Server */
    template<typename MReq, typename MRes>
    bool advertiseService(ServiceServer<MReq,MRes>& srv) {
        bool v = advertise(srv.pub);
        for (int i = 0; i < MAX_SUBSCRIBERS; i++) {
            if (subscribers[i] == 0) { // empty slot
                subscribers[i] = (Subscriber_*) &srv;
                srv.id_ = i+100;
                return v;
            }
        }
        return false;
    }

    /* Register a new Service Client */
    template<typename MReq, typename MRes>
    bool serviceClient(ServiceClient<MReq, MRes>& srv) {
        bool v = advertise(srv.pub);
        for (int i = 0; i < MAX_SUBSCRIBERS; i++) {
            if (subscribers[i] == 0) { // empty slot
                subscribers[i] = (Subscriber_*) &srv;
                srv.id_ = i+100;
                return v;
            }
        }
        return false;
    }

    void negotiateTopics() {
        configured_ = 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();
                ti.md5sum = (char *) publishers[i]->msg_->getMD5();
                ti.buffer_size = OUTPUT_SIZE;
                publish( publishers[i]->getEndpointType(), &ti );
            }
        }
        for (i = 0; i < MAX_SUBSCRIBERS; i++)
        {
            if (subscribers[i] != 0) // non-empty slot
            {
                ti.topic_id = subscribers[i]->id_;
                ti.topic_name = (char *) subscribers[i]->topic_;
                ti.message_type = (char *) subscribers[i]->getMsgType();
                ti.md5sum = (char *) subscribers[i]->getMsgMD5();
                ti.buffer_size = INPUT_SIZE;
                publish( subscribers[i]->getEndpointType(), &ti );
            }
        }
    }

    virtual int publish(int16_t id, const Msg * msg)
    {
        if (!configured_) return 0;

        /* serialize message */
        int16_t l = msg->serialize(message_out+6);

        /* setup the header */
        message_out[0] = 0xff;
        message_out[1] = 0xff;
        message_out[2] = (unsigned char) id&255;
        message_out[3] = (unsigned char) id>>8;
        message_out[4] = (unsigned char) l&255;
        message_out[5] = ((unsigned char) l>>8);

        /* calculate checksum */
        int chk = 0;
        for (int i =2; i<l+6; i++)
            chk += message_out[i];
        l += 6;
        message_out[l++] = 255 - (chk%256);

        if ( l <= OUTPUT_SIZE ) {
            hardware_.write(message_out, l);
            return l;
        } else {
            logerror("Message from device dropped: message larger than buffer.");
            return 1;
        }

    }

     /********************************************************************
     * Logging
     */

private:
    void log(char byte, const char * msg) {
        rosserial_msgs::Log l;
        l.level= byte;
        l.msg = (char*)msg;
        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);
    }


    /********************************************************************
     * 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;
        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