Geografic-Information-System/lib/vector/Vlib/rewind.c

/*!
   \file rewind.c

   \brief Vector library - rewind data

   Higher level functions for reading/writing/manipulating vectors.

   (C) 2001-2009 by the GRASS Development Team

   This program is free software under the GNU General Public License
   (>=v2).  Read the file COPYING that comes with GRASS for details.

   \author Original author CERL, probably Dave Gerdes or Mike Higgins.
   \author Update to GRASS 5.7 Radim Blazek and David D. Gray.
*/

#include <grass/vector.h>
#include <grass/glocale.h>


/*  Rewind vector data file to cause reads to start at beginning */
/* returns 0 on success, -1 on error */
static int rew_dummy()
{
    return -1;
}


#ifndef HAVE_OGR
static int format()
{
    G_fatal_error(_("Requested format is not compiled in this version"));
    return 0;
}
#endif


static int (*Rewind_array[][3]) () = {
    {
    rew_dummy, V1_rewind_nat, V2_rewind_nat}
#ifdef HAVE_OGR
    , {
    rew_dummy, V1_rewind_ogr, V2_rewind_ogr}
#else
    , {
    rew_dummy, format, format}
#endif
};


/*!
   \brief Rewind vector data file to cause reads to start at beginning

   \param Map vector map

   \return 0 on success
   \return -1 on error
 */
int Vect_rewind(struct Map_info *Map)
{
    if (!VECT_OPEN(Map))
	return -1;

    G_debug(1, "Vect_Rewind(): name = %s", Map->name);

    return (*Rewind_array[Map->format][Map->level]) (Map);
}