/* @(#)rr_insert.c	2.1 93/05/18 */
 
/******************************************************************************/
/* function    : rr_insert.c                                                  */
/*                                                                            */
/* subsystem   : chgen                                                        */
/*                                                                            */
/* input       : obj_ptr (rr obj ptr to insert) , table_head (table root)     */
/*                                                                            */
/* output      : table_head (may change if elt is now first)                  */
/*                                                                            */
/* returns     : table_head                                                   */
/*                                                                            */
/* author      : Steve Smith / Craig Smith                                    */
/*                                                                            */
/* created     : July, 1991                                                   */
/*                                                                            */
/* revisions   :                                                              */
/*                                                                            */
/* description : This routine will insert the specified node (pointed to by   */
/*               obj_ptr) into the rr_type list rooted by table_head.  The    */
/*               insert is performed in 'firstid' order.                      */
/*               The result of the routine is the new table_head.             */
/*                                                                            */
/******************************************************************************/


#include <stdio.h>
#include <ctype.h>
#include "chgen_define.h"
#include "chgen_externs.h"
#include "prototypes.h"

/* changed the return type of this function for OSF   maldred 22-Nov-95 */
struct rr_type * rr_insert ( obj_ptr , table_head )
struct rr_type *obj_ptr , *table_head ;
{
	static char rcsid[] = "$Id: rr_insert.c,v 1.3.4.1 1999/05/04 17:00:20 jkarner Exp $";
     struct rr_type *previous_ptr , *current_ptr ;

     current_ptr = table_head ; 
     if ( table_head == NULL )
                table_head = obj_ptr ;
     else
     {
        previous_ptr = current_ptr ;
        while ( ( current_ptr != NULL ) &&
                ( strcmp ( current_ptr->firstid , obj_ptr->firstid ) < 0 ) )
                /* traversing the link list sorted in ascending order
                   by the 1st field of a rr_type object and searching
                   for the right position to insert */
        {
                previous_ptr = current_ptr ;
                current_ptr = current_ptr->next_ptr ;
        }
        if ( current_ptr == table_head )
                /* new entry to be inserted in front of the link list */
        {
                obj_ptr->next_ptr = current_ptr ;
                table_head = obj_ptr ;
        }
        else
        {
                previous_ptr->next_ptr = obj_ptr ;
                obj_ptr->next_ptr = current_ptr ;
        }
     }
     return table_head ;
}