examples/receiver.c

// :vim ts=4 sw=4 noet:
/*
==================================================================================
    Copyright (c) 2019-2020 Nokia
    Copyright (c) 2018-2020 AT&T Intellectual Property.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
==================================================================================
*/

/*
    Mnemonic:   rmr_rcvr.c
    Abstract:   This is a very simple receiver that does nothing but listen
                for messages and write stats every so often to the tty.

                Define these environment variables to have some control:
                    RMR_SEED_RT -- path to the static routing table
                    RMR_RTG_SVC -- host:port of the route table generator

    Parms:      Two positional parameters are recognised on the command line:
                    [port [stats-freq]]

                where port is the port number to listen on and the stats frequency
                is the number of messages received which causes stats to be
                generated.  If not supplied the listen port default is 4560
                and the stats frequency is every 10 messages.

    Date:        1 April 2019
    Author:      E. Scott Daniels

    CAUTION:    This example is now being pulled directly into the user documentation.
                Because of this some altered line lengths and/or parameter list breaks
                which seem strage have been applied to ensure that it formats nicely.
                All code following the 'start_example' tag below is included.
*/
// start_example

#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#include <rmr/rmr.h>


int main( int argc, char** argv ) {
    void* mrc;                     // msg router context
    long long total = 0;
    rmr_mbuf_t* msg = NULL;        // message received
    int stat_freq = 10;            // write stats after reciving this many messages
    int i;
    char*    listen_port = "4560"; // default to what has become the standard RMR port
    long long count = 0;
    long long bad = 0;
    long long empty = 0;

    if( argc > 1 ) {
        listen_port = argv[1];
    }
    if( argc > 2 ) {
        stat_freq = atoi( argv[2] );
    }
    fprintf( stderr, "<DEMO> listening on port: %s\n", listen_port );
    fprintf( stderr, "<DEMO> stats will be reported every %d messages\n", stat_freq );

    mrc = rmr_init( listen_port, RMR_MAX_RCV_BYTES, RMRFL_NONE );
    if( mrc == NULL ) {
        fprintf( stderr, "<DEMO> ABORT:  unable to initialise RMr\n" );
        exit( 1 );
    }

    while( ! rmr_ready( mrc ) ) {	// wait for RMR to get a route table
        fprintf( stderr, "<DEMO> waiting for ready\n" );
        sleep( 3 );
    }
    fprintf( stderr, "<DEMO> rmr now shows ready\n" );

    while( 1 ) {                              // receive until killed
        msg = rmr_rcv_msg( mrc, msg );        // block until one arrives

        if( msg ) {
            if( msg->state == RMR_OK ) {
                count++;                      // nothing fancy, just count
            } else {
                bad++;
            }
        } else {
            empty++;
        }

        if( (count % stat_freq) == 0  ) {
            fprintf( stderr, "<DEMO> total received: %lld; errors: %lld; empty: %lld\n",
                count, bad, empty );
        }
    }
}