/grass-6.4.2/lib/vector/Vlib/array.c

/*!
   \file array.c

   \brief Vector library - array structure

   Higher level functions for reading/writing/manipulating vectors.

   (C) 2001-2008 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 Radim Blazek

   \date 2001-2008
 */

#include <stdlib.h>
#include <grass/gis.h>
#include <grass/dbmi.h>
#include <grass/Vect.h>
#include <grass/glocale.h>


/* function prototypes */
static int cmp(const void *pa, const void *pb);
static int in_array(int *cats, size_t ncats, int cat);


/*!
   \brief Create new VARRAY and allocate space for given number of items.

   Space allocated is 'size + 1' so that lines are accessed by line id.
   Array values are set to 0.

   \param size size of array

   \return pointer to new VARRAY
   \return NULL if failed
 */

VARRAY *Vect_new_varray(int size)
{
    VARRAY *p;

    p = (VARRAY *) G_malloc(sizeof(VARRAY));

    if (p == NULL)
	return NULL;

    p->size = size;
    p->c = (int *)G_calloc(sizeof(char) * size + 1, sizeof(int));

    if (p->c == NULL) {
	G_free(p);
	return NULL;
    }

    return p;
}

/*!
   \brief Set values in 'varray' to 'value'.

   If category of object of given type is in 'cstring' (string
   representing category list like: '1,3,5-7').  'type' may be either:
   GV_AREA or: GV_POINT | GV_LINE | GV_BOUNDARY | GV_CENTROID

   Array is not reset to zero before, but old values (if any > 0) are overwritten.
   Array must be initialised by Vect_new_varray(size) call.

   \param Map vector map
   \param field layer number
   \param cstring pointer to string with categories
   \param type feature type
   \param value value to set up
   \param[in,out] varray varray structure to modify

   \return number of items set
   \return -1 on error
 */
int
Vect_set_varray_from_cat_string(struct Map_info *Map, int field,
				const char *cstring, int type, int value,
				VARRAY * varray)
{
    int ret;
    struct cat_list *Clist;

    G_debug(4, "Vect_set_varray_from_cat_string(): cstring = '%s'", cstring);

    Clist = Vect_new_cat_list();

    ret = Vect_str_to_cat_list(cstring, Clist);

    if (ret > 0)
	G_warning(_("%d errors in category string."), ret);

    G_debug(4, "  %d ranges in clist", Clist->n_ranges);

    ret =
	Vect_set_varray_from_cat_list(Map, field, Clist, type, value, varray);

    Vect_destroy_cat_list(Clist);

    return ret;
}

/*!
   \brief Set values in 'varray' to 'value'

   If category of object of given type is in 'clist' (category list).
   'type' may be either: GV_AREA or: GV_POINT | GV_LINE | GV_BOUNDARY |
   GV_CENTROID

   Array is not reset to zero before, but old values (if any > 0) are overwritten.
   Array must be initialised by Vect_new_varray(size) call.

   \param Map vector map
   \param field layer number
   \param clist list of categories
   \param type feature type
   \param value value to set up
   \param[in,out] varray varray structure to modify

   \return number of items set
   \return -1 on error
 */
int
Vect_set_varray_from_cat_list(struct Map_info *Map, int field,
			      struct cat_list *clist, int type, int value,
			      VARRAY * varray)
{
    int i, n, centr, cat;
    int ni = 0;			/* number of items set */
    int ltype;			/* line type */
    struct line_cats *Cats;

    G_debug(4, "Vect_set_varray_from_cat_list(): field = %d", field);

    /* Check type */
    if ((type & GV_AREA) && (type & (GV_POINTS | GV_LINES))) {
	G_warning(_("Mixed area and other type requested for vector array"));
	return 0;
    }

    Cats = Vect_new_cats_struct();

    if (type & GV_AREA) {	/* Areas */
	n = Vect_get_num_areas(Map);

	if (n > varray->size) {	/* not enough space */
	    G_warning(_("Not enough space in vector array"));
	    return 0;
	}

	for (i = 1; i <= n; i++) {
	    centr = Vect_get_area_centroid(Map, i);
	    if (centr <= 0)
		continue;	/* No centroid */

	    Vect_read_line(Map, NULL, Cats, centr);
	    if (!Vect_cat_get(Cats, field, &cat))
		continue;	/* No such field */

	    if (Vect_cat_in_cat_list(cat, clist)) {	/* cat is in list */
		varray->c[i] = value;
		ni++;
	    }
	}
    }
    else {			/* Lines */
	n = Vect_get_num_lines(Map);

	if (n > varray->size) {	/* not enough space */
	    G_warning(_("Not enough space in vector array"));
	    return 0;
	}

	for (i = 1; i <= n; i++) {
	    ltype = Vect_read_line(Map, NULL, Cats, i);

	    if (!(ltype & type))
		continue;	/* is not specified type */

	    if (!Vect_cat_get(Cats, field, &cat))
		continue;	/* No such field */

	    if (Vect_cat_in_cat_list(cat, clist)) {	/* cat is in list */
		varray->c[i] = value;
		ni++;
	    }
	}

    }

    Vect_destroy_cats_struct(Cats);

    return ni;
}

/* compare 2 integers in array */
static int cmp(const void *pa, const void *pb)
{
    int *p1 = (int *)pa;
    int *p2 = (int *)pb;

    if (*p1 < *p2)
	return -1;
    if (*p1 > *p2)
	return 1;
    return 0;
}

/* check if cat is in array */
static int in_array(int *cats, size_t ncats, int cat)
{
    int *p;

    p = (int *)bsearch((void *)&cat, cats, ncats, sizeof(int), cmp);

    if (p == NULL)
	return 0;

    return 1;
}

/*!
   \brief Set values in 'varray' to 'value'.

   if category of object of given type is in categories selected from
   DB based on where statement (given without where).  'type' may be
   either: GV_AREA or: GV_POINT | GV_LINE | GV_BOUNDARY | GV_CENTROID

   Array is not reset to zero before, but old values (if any > 0) are
   overwritten. Array must be initialised by Vect_new_varray(size) call.

   \param Map vector map
   \param field layer number
   \param where where statement
   \param type feature type
   \param value value to set up
   \param[in,out] varray varray structure to modify

   \return number of items set
   \return -1 on error
 */
int
Vect_set_varray_from_db(struct Map_info *Map, int field, const char *where,
			int type, int value, VARRAY * varray)
{
    int i, n, c, centr, cat, *cats;
    int ncats;
    int ni = 0;			/* number of items set */
    int ltype;			/* line type */
    struct line_cats *Cats;
    struct field_info *Fi;
    dbDriver *driver;

    G_debug(4, "Vect_set_varray_from_db(): field = %d where = '%s'", field,
	    where);

    /* Note: use category index once available */

    /* Check type */
    if ((type & GV_AREA) && (type & (GV_POINTS | GV_LINES))) {
	G_warning(_("Mixed area and other type requested for vector array"));
	return 0;
    }

    Cats = Vect_new_cats_struct();

    /* Select categories from DB to array */
    Fi = Vect_get_field(Map, field);
    if (Fi == NULL) {
	G_warning(_("Database connection not defined for layer %d"), field);
	return -1;
    }

    driver = db_start_driver_open_database(Fi->driver, Fi->database);
    if (driver == NULL) {
	G_warning(_("Unable to open database <%s> by driver <%s>"),
		  Fi->database, Fi->driver);
	return -1;
    }

    ncats = db_select_int(driver, Fi->table, Fi->key, where, &cats);

    db_close_database_shutdown_driver(driver);

    if (ncats == -1) {
	G_warning(_("Unable to select record from table <%s> (key %s, where %s)"),
		  Fi->table, Fi->key, where);
	return -1;
    }

    if (type & GV_AREA) {	/* Areas */
	n = Vect_get_num_areas(Map);

        /* IMHO varray should be allocated only when it's required AND only as large as required
        as WHERE will create a small subset of all vector features and thus on large datasets
        it's waste of memory to allocate it for all features. */
	if (n > varray->size) {	/* not enough space */
	    G_warning(_("Not enough space in vector array"));
	    return 0;
	}

	for (i = 1; i <= n; i++) {
	    centr = Vect_get_area_centroid(Map, i);
	    if (centr <= 0)
		continue;	/* No centroid */

	    Vect_read_line(Map, NULL, Cats, centr);
	    /*if ( !Vect_cat_get(Cats, field, &cat) ) continue; No such field */
	    for (c = 0; c < Cats->n_cats; c++) {
		if (Cats->field[c] == field &&
		    in_array(cats, ncats, Cats->cat[c])) {
		    cat = Cats->cat[c];
		    varray->c[i] = value;
		    ni++;
		    break;
		}
	    }

	    /*
	       if ( in_array ( cats, ncats, cat ) ) {
	       varray->c[i] = value;
	       ni++;
	       }
	     */
	}
    }
    else {			/* Lines */
	n = Vect_get_num_lines(Map);

	if (n > varray->size) {	/* not enough space */
	    G_warning(_("Not enough space in vector array"));
	    return 0;
	}

	for (i = 1; i <= n; i++) {
	    ltype = Vect_read_line(Map, NULL, Cats, i);

	    if (!(ltype & type))
		continue;	/* is not specified type */

	    /* if ( !Vect_cat_get(Cats, field, &cat) ) continue;  No such field */
	    for (c = 0; c < Cats->n_cats; c++) {
		if (Cats->field[c] == field &&
		    in_array(cats, ncats, Cats->cat[c])) {
		    cat = Cats->cat[c];
		    varray->c[i] = value;
		    ni++;
		    break;
		}
	    }
	    /*
	       if ( in_array ( cats, ncats, cat ) ) {
	       varray->c[i] = value;
	       ni++;
	       }
	     */
	}

    }

    G_free(cats);
    Vect_destroy_cats_struct(Cats);

    return ni;
}