Siena C++ API Documentation

This is an example of how to program a simple subscriber application. To compile this example on a GNU/Linux system or on other Unix-like systems, assuming Siena has been installed in $prefix, execute:

On some platforms (notably Solaris), you will have to link additional libraris (e.g., -lsocket -lnsl).

To compile this example on a win32 system, using Visual C++, assuming Siena has been installed in %prefix%, execute:

// -*- C++ -*-
//
//  This file is part of Siena, a wide-area event notification system.
//  See http://www.cs.colorado.edu/serl/siena/
//
//  Author: Antonio Carzaniga <carzanig@cs.colorado.edu>
//  See the file AUTHORS for full details. 
//
//  Copyright (C) 1998-2001 University of Colorado
//
//  This program is free software; you can redistribute it and/or
//  modify it under the terms of the GNU General Public License
//  as published by the Free Software Foundation; either version 2
//  of the License, or (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307,
//  USA, or send email to serl@cs.colorado.edu.
//
// $Id: subscriber.cc,v 1.2 2001/06/26 22:03:03 carzanig Exp $
//
#include <string.h>
#include <stdlib.h>

#include <iostream>
#include <exception>
                                                // include Siena headers
#include <siena/Siena.h>
#include <siena/ThinClient.h>

static void print_usage(const char * progname) {
    cerr << "usage: " << progname 
         << " [-udp] [-port <num>] [-host <host>] <uri-master>" << endl;
}

int main (int argc, char *argv[])
{
    bool udp = false;
    unsigned short port = 1969;
    const char * master = NULL;
    const char * thishost = NULL;
    
    try {
        int i;
        for(i=1; i < argc; ++i) {               // parse cmd-line params
            if(strcmp(argv[i], "-udp")==0) {
                udp = true;
            } else if (strcmp(argv[i], "-port")==0) {
                if (++i < argc) {
                    port = atoi(argv[i]);
                } else {
                    print_usage(argv[0]);
                    return 1;
                }
            } else if (strcmp(argv[i], "-host")==0) {
                if (++i < argc) {
                    thishost = argv[i];
                } else {
                    print_usage(argv[0]);
                    return 1;
                }
            } else {
                master = argv[i];
            }
        }
        if (master == NULL) {
            print_usage(argv[0]);
            return 1;
        }

        ThinClient siena(master);               // create interface to
        Receiver * r;                           // given master server
        if (udp) {
            r = new UDPReceiver(port, thishost);// create receiver for 
        } else {                                // this interface
            r = new TCPReceiver(port, thishost);
        }
        siena.set_receiver(r);                  // set receiver

        Filter f;                               // create subscription filter
        f.add_constraint("stock", SX_eq, "XYZ");
        f.add_constraint("price", SX_lt, (long)100);
        siena.subscribe(f);                     // subscribe

        Notification * n;

        for (i = 1; i < 20; ++i) {              // read incoming notifications
            n = siena.get_notification();
            if (n != NULL)  {
                cout << "stock=" << (*n)["stock"].string_value()
                     << " price=" << (*n)["price"].int_value() << endl;
                delete(n);
            }
        }
        siena.unsubscribe();                    // unsubscribe and shutdown 
        siena.shutdown();                       // interface
        delete(r);
    } catch (exception &ex) {
        cout << "error: " << ex.what() << endl;
    }
    return 0;
}