Vector library - reading features (PostGIS format) More...

#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <grass/vector.h>
#include <grass/dbmi.h>
#include <grass/glocale.h>
#include "local_proto.h"
#include "pg_local_proto.h"

Include dependency graph for read_pg.c:

Go to the source code of this file.

Macros
#define	NOPG_UNUSED

Functions
SF_FeatureType	get_feature (struct Map_info *Map, int fid, int type)
	Read feature geometry.

int	V1_read_next_line_pg (struct Map_info Map, struct line_pnts line_p, struct line_cats *line_c)
	Read next feature from PostGIS layer. Skip empty features (level 1 without topology). t This function implements sequential access.

int	V2_read_next_line_pg (struct Map_info Map, struct line_pnts line_p, struct line_cats *line_c)
	Read next feature from PostGIS layer on topological level (simple feature access).

int	V1_read_line_pg (struct Map_info Map, struct line_pnts line_p, struct line_cats *line_c, off_t offset)
	Read feature from PostGIS layer at given offset (level 1 without topology)

int	V2_read_line_pg (struct Map_info Map, struct line_pnts line_p, struct line_cats *line_c, int line)
	Read feature from PostGIS layer on topological level.

SF_FeatureType	Vect__cache_feature_pg (const char data, int skip_polygon, int force_type, struct Format_info_cache cache, struct feat_parts *fparts)
	Read geometry from HEX data.

int	Vect__open_cursor_next_line_pg (struct Format_info_pg *pg_info, int fetch_all, int built_level)
	Create select cursor for sequential access (internal use only)

int	Vect__open_cursor_line_pg (struct Format_info_pg *pg_info, int fid, int type)
	Open select cursor for random access (internal use only)

int	Vect__close_cursor_pg (struct Format_info_pg *pg_info)
	Close select cursor.

int	Vect__select_line_pg (struct Format_info_pg *pg_info, int fid, int type)
	Select feature (internal use only)

int	Vect__execute_pg (PGconn conn, const char stmt)
	Execute SQL statement.

int	Vect__execute_get_value_pg (PGconn conn, const char stmt)
	Execute SQL statement and get value.

void	Vect__reallocate_cache (struct Format_info_cache *cache, int num, int incr)
	Reallocate lines cache.

Detailed Description

Vector library - reading features (PostGIS format)

Higher level functions for reading/writing/manipulating vectors.

Todo:: Currently only points, linestrings and polygons are supported, implement also other types

Todo:: Support multigeometries

Todo:: PostGIS Topology - fix category handling (read categories from feature table)

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

Author: Martin Landa <landa.martin gmail.com>

Definition in file read_pg.c.

Macro Definition Documentation

◆ NOPG_UNUSED

#define NOPG_UNUSED

Definition at line 62 of file read_pg.c.

Function Documentation

◆ get_feature()

SF_FeatureType get_feature	(	struct Map_info *	Map,
		int	fid,
		int	type
	)

Read feature geometry.

Geometry is stored in lines cache.

Parameters

[in,out]	Map	pointer to Map_info struct
	fid	feature id to be read (-1 for next)
	type	feature type (GV_POINT, GV_LINE, ...) - use only for topological access

Returns: simple feature type (SF_POINT, SF_LINESTRING, ...); -1 on error

Definition at line 580 of file read_pg.c.

References _, DB_SQL_MAX, FALSE, G_debug(), G_warning(), GV_BOUNDARY, GV_CENTROID, GV_LINE, GV_POINT, GV_POINTS, NULL, SF_POLYGON, Vect__cache_feature_pg(), Vect__close_cursor_pg(), Vect__open_cursor_line_pg(), Vect__open_cursor_next_line_pg(), and Vect__select_line_pg().

Referenced by V1_read_line_pg(), and V2_read_line_pg().

◆ V1_read_line_pg()

int V1_read_line_pg	(	struct Map_info *	Map,
		struct line_pnts *	line_p,
		struct line_cats *	line_c,
		off_t	offset
	)

Read feature from PostGIS layer at given offset (level 1 without topology)

This function implements random access on level 1.

Parameters

	Map	pointer to Map_info structure
[out]	line_p	container used to store line points within (pointer line_pnts struct)
[out]	line_c	container used to store line categories within (pointer line_cats struct)
	offset	given offset

Returns: line type; 0 dead line; -2 no more features; -1 out of memory

Definition at line 245 of file read_pg.c.

References _, G_debug(), G_fatal_error(), G_warning(), get_feature(), GV_FORWARD, NULL, Format_info_pg::offset, SF_LINESTRING, SF_NONE, SF_POINT, Vect_append_points(), Vect_cat_set(), Vect_reset_cats(), and Vect_reset_line().

Referenced by V1_rewrite_line_pg(), and V2_read_line_sfa().

◆ V1_read_next_line_pg()

int V1_read_next_line_pg	(	struct Map_info *	Map,
		struct line_pnts *	line_p,
		struct line_cats *	line_c
	)

Read next feature from PostGIS layer. Skip empty features (level 1 without topology). t This function implements sequential access.

The action of this routine can be modified by:

Vect_read_constraint_region()
Vect_read_constraint_type()
Vect_remove_constraints()

Parameters

	Map	pointer to Map_info structure
[out]	line_p	container used to store line points within (pointer to line_pnts struct)
[out]	line_c	container used to store line categories within (pointer line_cats struct)

Returns: feature type; -2 no more features (EOF); -1 out of memory

Definition at line 88 of file read_pg.c.

References _, FALSE, G_debug(), and G_fatal_error().

◆ V2_read_line_pg()

int V2_read_line_pg	(	struct Map_info *	Map,
		struct line_pnts *	line_p,
		struct line_cats *	line_c,
		int	line
	)

Read feature from PostGIS layer on topological level.

This function implements random access on level 2.

Note: Topology must be built at level >= GV_BUILD_BASE

Parameters

	Map	pointer to Map_info structure
[out]	line_p	container used to store line points within (pointer line_pnts struct)
[out]	line_c	container used to store line categories within (pointer line_cats struct)
	line	feature id to read

Returns: feature type; 0 dead feature; -1 on error

Definition at line 328 of file read_pg.c.

References _, G_debug(), G_fatal_error(), G_warning(), get_feature(), GV_CENTROID, GV_FORWARD, GV_POINTS, NULL, P_line::offset, SF_NONE, P_line::type, Vect__select_line_pg(), Vect_append_points(), Vect_cat_set(), Vect_reset_cats(), and Vect_reset_line().

Referenced by V2_delete_line_pg(), and V2_rewrite_line_pg().

◆ V2_read_next_line_pg()

int V2_read_next_line_pg	(	struct Map_info *	Map,
		struct line_pnts *	line_p,
		struct line_cats *	line_c
	)

Read next feature from PostGIS layer on topological level (simple feature access).

This function implements sequential access.

Parameters

	Map	pointer to Map_info structure
[out]	line_p	container used to store line points within (pointer to line_pnts struct)
[out]	line_c	container used to store line categories within (pointer to line_cats struct)

Returns: feature type; -2 no more features (EOF); -1 on failure

Definition at line 119 of file read_pg.c.

References _, P_topo_c::area, dig_init_boxlist(), G_debug(), G_fatal_error(), G_warning(), GV_CENTROID, NULL, P_line::offset, P_line::topo, TRUE, P_line::type, Vect_append_point(), Vect_box_overlap(), Vect_cat_set(), Vect_get_area_box(), Vect_get_constraint_box(), Vect_line_box(), Vect_reset_cats(), Vect_reset_line(), and Vect_select_lines_by_box().

◆ Vect__cache_feature_pg()

SF_FeatureType Vect__cache_feature_pg	(	const char *	data,
		int	skip_polygon,
		int	force_type,
		struct Format_info_cache *	cache,
		struct feat_parts *	fparts
	)

Read geometry from HEX data.

This code is inspired by OGRGeometryFactory::createFromWkb() from GDAL/OGR library.

Parameters

	data	HEX data
	skip_polygon	skip polygons (level 1)
	force_type	force GV_BOUNDARY or GV_CENTROID (used for PostGIS topology only)
[out]	cache	lines cache
[out]	fparts	used for building pseudo-topology (or NULL)