vector/Vlib/rewind.c

Go to the documentation of this file.

/*!
   \file lib/vector/Vlib/rewind.c
 
   \brief Vector library - rewind data
 
   Higher level functions for reading/writing/manipulating vectors.
 
   (C) 2001-2009, 2011-2012 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.
   \author Level 3 by Martin Landa <landa.martin gmail.com>
 */
 
#include <grass/vector.h>
#include <grass/glocale.h>
 
static int rew_dummy(struct Map_info *Map UNUSED)
{
    return -1;
}
 
#if !defined HAVE_OGR || !defined HAVE_POSTGRES
static int format(struct Map_info *Map UNUSED)
{
    G_fatal_error(_("Requested format is not compiled in this version"));
    return 0;
}
#endif
 
static int (*Rewind_array[][4])(struct Map_info *) = {
    {rew_dummy, V1_rewind_nat, V2_rewind_nat, rew_dummy}
#ifdef HAVE_OGR
    ,
    {rew_dummy, V1_rewind_ogr, V2_rewind_ogr, rew_dummy},
    {rew_dummy, V1_rewind_ogr, V2_rewind_ogr, rew_dummy}
#else
    ,
    {rew_dummy, format, format, rew_dummy},
    {rew_dummy, format, format, rew_dummy}
#endif
#ifdef HAVE_POSTGRES
    ,
    {rew_dummy, V1_rewind_pg, V2_rewind_pg, V2_rewind_pg}
#else
    ,
    {rew_dummy, format, format, rew_dummy}
#endif
};
 
/*!
   \brief Rewind vector map to cause reads to start at beginning
 
   \param Map pointer to Map_info structure
 
   \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 level = %d", Map->name, Map->level);
 
    return (*Rewind_array[Map->format][Map->level])(Map);
}