RosLookup.cpp

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/*
 * SPDX-FileCopyrightText: 2006-2021 Istituto Italiano di Tecnologia (IIT)
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
#include "RosLookup.h"
#include "TcpRosLogComponent.h"
 
#include <yarp/conf/environment.h>
 
#include <yarp/os/Bottle.h>
#include <yarp/os/ContactStyle.h>
#include <yarp/os/Network.h>
 
#include <cstdlib>
 
using namespace yarp::os;
 
static bool rpc(const Contact& c,
                const char *carrier,
                Bottle& writer,
                Bottle& reader)
{
    ContactStyle style;
    style.quiet = false;
    style.timeout = 4;
    style.carrier = carrier;
    yCDebug(TCPROSCARRIER,
            "  > sending to [%s] %s",
            c.toString().c_str(),
            writer.toString().c_str());
    bool ok = Network::write(c,writer,reader,style);
    return ok;
}
 
bool RosLookup::lookupCore(const std::string& name) {
    Bottle req, reply;
    req.addString("lookupNode");
    req.addString("dummy_id");
    req.addString(name);
    rpc(getRosCoreAddress(), "xmlrpc", req, reply);
    if (reply.get(0).asInt32()!=1) {
        yCError(TCPROSCARRIER, "Failure: %s", reply.toString().c_str());
        return false;
    }
    std::string url = reply.get(2).asString();
    std::string::size_type break1 = url.find("://",0);
    if (break1==std::string::npos) {
        yCError(TCPROSCARRIER, "url not understood: %s", url.c_str());
        return false;
    }
    std::string::size_type break2 = url.find(':',break1+3);
    if (break2==std::string::npos) {
        yCError(TCPROSCARRIER, "url not understood: %s", url.c_str());
        return false;
    }
    std::string::size_type break3 = url.find('/',break2+1);
    if (break3==std::string::npos) {
        yCError(TCPROSCARRIER, "url not understood: %s", url.c_str());
        return false;
    }
    hostname = url.substr(break1+3,break2-break1-3);
    Value vportnum;
    vportnum.fromString(url.substr(break2+1,break3-break2-1).c_str());
    portnum = vportnum.asInt32();
    yCDebug(TCPROSCARRIER, "%s", reply.toString().c_str());
    valid = (portnum!=0);
    rpc(getRosCoreAddress(), "xmlrpc", req, reply);
    return valid;
}
 
 
bool RosLookup::lookupTopic(const std::string& name) {
    if (!valid) {
        yCError(TCPROSCARRIER, "Need a node");
        return false;
    }
    Bottle req, reply;
    req.addString("requestTopic");
    req.addString("dummy_id");
    req.addString(name);
    Bottle& lst = req.addList();
    Bottle& sublst = lst.addList();
    sublst.addString("TCPROS");
    yCDebug(TCPROSCARRIER,
            "Sending [%s] to %s",
            req.toString().c_str(),
            toString().c_str());
    Contact c = Contact::fromString(toString());
    rpc(c,"xmlrpc",req,reply);
    if (reply.get(0).asInt32()!=1) {
        yCError(TCPROSCARRIER, "Failure looking up topic %s: %s", name.c_str(), reply.toString().c_str());
        return false;
    }
    Bottle *pref = reply.get(2).asList();
    if (pref==nullptr) {
        yCError(TCPROSCARRIER, "Failure looking up topic %s: expected list of protocols", name.c_str());
        return false;
    }
    if (pref->get(0).asString()!="TCPROS") {
        yCError(TCPROSCARRIER, "Failure looking up topic %s: unsupported protocol %s", name.c_str(),
               pref->get(0).asString().c_str());
        return false;
    }
    Value hostname2 = pref->get(1);
    Value portnum2 = pref->get(2);
    hostname = hostname2.asString();
    portnum = portnum2.asInt32();
    protocol = "tcpros";
    yCDebug(TCPROSCARRIER,
            "topic %s available at %s:%d",
            name.c_str(),
            hostname.c_str(),
            portnum);
    return true;
}
 
yarp::os::Contact RosLookup::getRosCoreAddressFromEnv() {
    std::string addr = yarp::conf::environment::get_string("ROS_MASTER_URI");
    Contact c = Contact::fromString(addr);
    if (c.isValid()) {
        c.setCarrier("xmlrpc");
    }
    return c;
}
 
yarp::os::Contact RosLookup::getRosCoreAddress() {
    static bool checkedEnv = false;
    static Contact addr;
    if (!checkedEnv) {
        Contact c = getRosCoreAddressFromEnv();
        addr = c;
        checkedEnv = true;
    }
    if (!addr.isValid()) {
        addr = NetworkBase::queryName("/roscore");
    }
    if (!addr.isValid()) {
        yCError(TCPROSCARRIER, "cannot find roscore, is ROS_MASTER_URI set?");
        ::exit(1);
    }
    return addr;
}