source: libcfa/src/parseconfig.cfa @ 6604ea1

#include <fstream.hfa>
#include <parseargs.hfa>
#include "parseconfig.hfa"


// *********************************** exceptions ***********************************


EHM_VIRTUAL_TABLE(Validation_Failure, Validation_Failure_main_table);
void ?{}( Validation_Failure & this, config_entry & entry ) with ( entry ) {
        this.virtual_table = &Validation_Failure_main_table;
        this.key = key;
        this.variable = variable;
}
void throwValidation_Failure( config_entry & entry ) {
        Validation_Failure exc = { entry };
}


// *********************************** main code ***********************************


struct KVPairs {
        int size, max_size;
        * [ char *, char * ] data;
};
void ?{}( KVPairs & kvp ) with ( kvp ) {        // default constructor
        size = 0; max_size = 0; data = 0p;
}
void ?{}( KVPairs & kvp, int size ) {           // initialization
        kvp.[ size, max_size ] = [ 0, size ];
        kvp.data = alloc( size );
}
void ^?{}( KVPairs & kvp ) with ( kvp ) {       // destructor
        free( data );
        size = 0; max_size = 0; data = 0p;
}

void add_kv_pair( KVPairs kv_pairs, char * k, char * v ) with ( kv_pairs ) {
        if ( size == max_size ) {
                max_size *= 2;
                data = resize( data, max_size );
        }

        data[size] = [ k, v ];
        ++size;
}

bool comments( ifstream & in, char * name ) {
        while () {
                in | name;
          if ( fail( in ) ) return true;
          if ( name[0] != '#' ) break;
                in | nl;        // ignore remainder of line
        } // for
        return false;
} // comments

// Parse configuration from a file formatted in shell style
KVPairs & parse_shell_config_format( const char * config_file, size_t num_entries ) {
        KVPairs kv_pairs = { num_entries };

        ifstream in;
        try {
                open( in, config_file );                                                        // open the configuration file for input

                while () {
                        char * key;
                        char * value;
                  if ( comments( in, key ) ) break;                     // eof ?
                        // Should we just overwrite duplicate config entries? Having a hash map would make this much easier
                        in | value;

                        add_kv_pair( kv_pairs, key, value );

                  if ( fail( in ) ) break;
                        in | nl; // ignore remainder of line
                } // for
        } catch( Open_Failure * ex; ex->istream == &in ) {
                exit | "Error: could not open input file \"" | config_file | "\"";
        } // try
        close( in );

        return kv_pairs;
}

// Parse configuration values from intermediate format
void parse_config( const char * config_file, config_entry entries[], size_t num_entries ) {
        KVPairs kv_pairs = parse_shell_config_format( config_file, num_entries );

        int entries_so_far = 0;
        for ( i; kv_pairs.size ) {
          if ( entries_so_far == num_entries ) break;

                char * src_key, * src_value;
                [ src_key, src_value ] = kv_pairs.data[i];

                for ( j; num_entries ) {
                  if ( strcmp( src_key, entries[j].key ) != 0 ) continue;
                        if ( entries[j].parse( src_value, entries[j].variable ) ) {
                                ++entries_so_far;

                                // Validate the parsed data, if necessary
                                if ( entries[j].validate != 0p ) {
                                        if ( !entries[j].validate( entries[j].variable ) ) throwValidation_Failure( entries[j] );
                                }

                                break;
                        }

                        serr | "Value '" | src_value | "' for key '" | src_key | "' could not be parsed";
                }
        }
} // processConfigFile


// Local Variables: //
// tab-width: 4 //
// compile-command: "cfa parseconfig.cfa" //
// End: //