Application: gvSIG desktop

/******************************************************************************

 * $Id: pj_gridlist.c,v 1.3 2003/03/18 16:26:58 warmerda Exp $

 *

 * Project:  PROJ.4

 * Purpose:  Code to manage the list of currently loaded (cached) PJ_GRIDINFOs

 *           See pj_gridinfo.c for details of loading individual grids.

 * Author:   Frank Warmerdam, warmerdam@pobox.com

 *

 ******************************************************************************

 * Copyright (c) 2000, Frank Warmerdam <warmerdam@pobox.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the "Software"),

 * to deal in the Software without restriction, including without limitation

 * the rights to use, copy, modify, merge, publish, distribute, sublicense,

 * and/or sell copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included

 * in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

 * DEALINGS IN THE SOFTWARE.

 ******************************************************************************

 *

 * $Log: pj_gridlist.c,v $

 * Revision 1.3  2003/03/18 16:26:58  warmerda

 * clear error if missing file is not required

 *

 * Revision 1.2  2003/03/17 19:45:47  warmerda

 * support '@' marker for optional grids

 *

 * Revision 1.1  2003/03/15 06:01:18  warmerda

 * New

 *

 */

#define PJ_LIB__

#include <projects.h>

#include <string.h>

#include <math.h>

#include <assert.h>

static PJ_GRIDINFO *grid_list = NULL;

/* used only by pj_load_nadgrids() and pj_deallocate_grids() */

static int           last_nadgrids_max = 0;

static int           last_nadgrids_count = 0;

static PJ_GRIDINFO **last_nadgrids_list = NULL;

static char         *last_nadgrids = NULL;

/************************************************************************/

/*                        pj_deallocate_grids()                         */

/*                                                                      */

/*      Deallocate all loaded grids.                                    */

/************************************************************************/

void pj_deallocate_grids()

{

    while( grid_list != NULL )

    {

        PJ_GRIDINFO *item = grid_list;

        grid_list = grid_list->next;

        item->next = NULL;

        pj_gridinfo_free( item );

    }

    if( last_nadgrids != NULL )

    {

        pj_dalloc( last_nadgrids );

        last_nadgrids = NULL;

        pj_dalloc( last_nadgrids_list );

        last_nadgrids_list = NULL;

        last_nadgrids_count = 0;

        last_nadgrids_max = 0;

    }

}

/************************************************************************/

/*                       pj_gridlist_merge_grid()                       */

/*                                                                      */

/*      Find/load the named gridfile and merge it into the              */

/*      last_nadgrids_list.                                             */

/************************************************************************/

static int pj_gridlist_merge_gridfile( const char *gridname )

{

    int i, got_match=0;

    PJ_GRIDINFO *this_grid, *tail = NULL;

/* -------------------------------------------------------------------- */

/*      Try to find in the existing list of loaded grids.  Add all      */

/*      matching grids as with NTv2 we can get many grids from one      */

/*      file (one shared gridname).                                     */

/* -------------------------------------------------------------------- */

    for( this_grid = grid_list; this_grid != NULL; this_grid = this_grid->next)

    {

        if( strcmp(this_grid->gridname,gridname) == 0 )

        {

            got_match = 1;

            /* dont add to the list if it is invalid. */

            if( this_grid->ct == NULL )

                return 0;

            /* do we need to grow the list? */

            if( last_nadgrids_count >= last_nadgrids_max - 2 )

            {

                PJ_GRIDINFO **new_list;

                int new_max = last_nadgrids_max + 20;

                new_list = (PJ_GRIDINFO **) pj_malloc(sizeof(void*) * new_max);

                if( last_nadgrids_list != NULL )

                {

                    memcpy( new_list, last_nadgrids_list, 

                            sizeof(void*) * last_nadgrids_max );

                    pj_dalloc( last_nadgrids_list );

                }

                last_nadgrids_list = new_list;

                last_nadgrids_max = new_max;

            }

            /* add to the list */

            last_nadgrids_list[last_nadgrids_count++] = this_grid;

            last_nadgrids_list[last_nadgrids_count] = NULL;

        }

        tail = this_grid;

    }

    if( got_match )

        return 1;

/* -------------------------------------------------------------------- */

/*      Try to load the named grid.                                     */

/* -------------------------------------------------------------------- */

    this_grid = pj_gridinfo_init( gridname );

    if( this_grid == NULL )

    {

        /* we should get at least a stub grid with a missing "ct" member */

        assert( FALSE );

        return 0;

    }

    if( tail != NULL )

        tail->next = this_grid;

    else

        grid_list = this_grid;

/* -------------------------------------------------------------------- */

/*      Recurse to add the grid now that it is loaded.                  */

/* -------------------------------------------------------------------- */

    return pj_gridlist_merge_gridfile( gridname );

}

/************************************************************************/

/*                     pj_gridlist_from_nadgrids()                      */

/*                                                                      */

/*      This functions loads the list of grids corresponding to a       */

/*      particular nadgrids string into a list, and returns it.  The    */

/*      list is kept around till a request is made with a different     */

/*      string in order to cut down on the string parsing cost, and     */

/*      the cost of building the list of tables each time.              */

/************************************************************************/

PJ_GRIDINFO **pj_gridlist_from_nadgrids( const char *nadgrids, int *grid_count)

{

    const char *s;

    pj_errno = 0;

    *grid_count = 0;

    if( last_nadgrids != NULL 

        && strcmp(nadgrids,last_nadgrids) == 0 )

    {

        *grid_count = last_nadgrids_count;

        return last_nadgrids_list;

    }

/* -------------------------------------------------------------------- */

/*      Free old one, if any, and make space for new list.              */

/* -------------------------------------------------------------------- */

    if( last_nadgrids != NULL )

    {

        pj_dalloc(last_nadgrids);

    }

    last_nadgrids = (char *) pj_malloc(strlen(nadgrids)+1);

    strcpy( last_nadgrids, nadgrids );

    last_nadgrids_count = 0;

/* -------------------------------------------------------------------- */

/*      Loop processing names out of nadgrids one at a time.            */

/* -------------------------------------------------------------------- */

    for( s = nadgrids; *s != '\0'; )

    {

        int   end_char;

        int   required = 1;

        char  name[128];

        if( *s == '@' )

        {

            required = 0;

            s++;

        }

        for( end_char = 0; 

             s[end_char] != '\0' && s[end_char] != ','; 

             end_char++ ) {}

        if( end_char > sizeof(name) )

        {

            pj_errno = -38;

            return NULL;

        }

        strncpy( name, s, end_char );

        name[end_char] = '\0';

        s += end_char;

        if( *s == ',' )

            s++;

        if( !pj_gridlist_merge_gridfile( name ) && required )

        {

            pj_errno = -38;

            return NULL;

        }

        else

            pj_errno = 0;

    }

    if( last_nadgrids_count > 0 )

    {

        *grid_count = last_nadgrids_count;

        return last_nadgrids_list;

    }

    else

        return NULL;

}