wreport/doxygen/examples.html

/*

 * input - BUFR and CREX input examples

 *

 * Copyright (C) 2011  ARPA-SIM <urpsim@smr.arpa.emr.it>

 *

 * 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.

 *

 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA

 *

 * Author: Enrico Zini <enrico@enricozini.com>

 */


#include <wreport/bulletin.h>

#include "options.h"


using namespace wreport;


// Read all BUFR messages from a file

void read_bufr_raw(const Options& opts, const char* fname, RawHandler& handler)

{

    // Open the input file

    FILE* in = fopen(fname, "rb");

    if (in == NULL)

        error_system::throwf("opening file %s", fname);


    // Use a generic try/catch block to ensure we always close the input file,

    // even in case of errors

    try {

        // String used to hold raw data read from the input file

        std::string raw_data;


        // (optional) offset of the start of the BUFR message read, which we

        // pass to the decoder to have nicer error messages

        off_t offset;


        // Read all BUFR data in the input file, one message at a time. Extra

        // data before and after each BUFR message is skipped.

        // fname and offset are optional and we pass them just to have nicer

        // error messages.

        while (BufrBulletin::read(in, raw_data, fname, &offset))

            handler.handle_raw_bufr(raw_data, fname, offset);


        // Cleanup

        fclose(in);

    } catch (...) {

        fclose(in);

        throw;

    }

}


/*

 * Read all CREX messages from a file

 *

 * Note that the code is basically the same as with reading BUFRs, with only

 * two changes:

 *  - it uses a CrexBulletin instead of a BufrBulletin

 *  - it uses CrexBulletin::read instead of BufrBulletin::read

 */

void read_crex_raw(const Options& opts, const char* fname, RawHandler& handler)

{

    // Open the input file

    FILE* in = fopen(fname, "rt");

    if (in == NULL)

        error_system::throwf("opening file %s", fname);


    // Use a generic try/catch block to ensure we always close the input file,

    // even in case of errors

    try {

        // Create a CREX bulletin

        unique_ptr<Bulletin> bulletin(CrexBulletin::create());


        // String used to hold raw data read from the input file

        string raw_data;


        // (optional) offset of the start of the CREX message read, which we

        // pass to the decoder to have nicer error messages

        off_t offset;


        // Read all CREX data in the input file, one message at a time. Extra

        // data before and after each CREX message is skipped.

        // fname and offset are optional and we pass them just to have nicer

        // error messages.

        while (CrexBulletin::read(in, raw_data, fname, &offset))

            handler.handle_raw_crex(raw_data, fname, offset);


        // Cleanup

        fclose(in);

    } catch (...) {

        fclose(in);

        throw;

    }

}