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

#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.

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

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. More...

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). More...

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) More...

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. More...

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. More...

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) More...

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) More...

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

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

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

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

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

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.

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 564 of file read_pg.c.

◆ 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 237 of file read_pg.c.

◆ 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 82 of file read_pg.c.

References G_debug().

◆ 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 319 of file read_pg.c.

◆ 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 112 of file read_pg.c.

◆ 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)

Returns: simple feature type; SF_GEOMETRY on error

Definition at line 757 of file read_pg.c.

◆ Vect__close_cursor_pg()

int Vect__close_cursor_pg ( struct Format_info_pg * pg_info )

Close select cursor.

Parameters

pg_info pointer to Format_info_pg struct

Returns: 0 on success; -1 on failure

Definition at line 1408 of file read_pg.c.

References _, Format_info_pg::conn, Format_info_pg::cursor_name, DB_SQL_MAX, G_free(), G_warning(), NULL, Format_info_pg::res, and Vect__execute_pg().

Referenced by V1_rewind_pg().

◆ Vect__execute_get_value_pg()

int Vect__execute_get_value_pg	(	PGconn *	conn,
		const char *	stmt
	)

Execute SQL statement and get value.

Parameters

conn	pointer to PGconn
stmt	query

Returns: value on success; -1 on error

Definition at line 1548 of file read_pg.c.

References _, G_debug(), G_warning(), and NULL.

Referenced by Vect_sfa_get_num_features().

◆ Vect__execute_pg()

int Vect__execute_pg	(	PGconn *	conn,
		const char *	stmt
	)

Execute SQL statement.

See pg_local_proto.h

Parameters

conn	pointer to PGconn
stmt	query

Returns: 0 on success; -1 on error

Definition at line 1514 of file read_pg.c.

References _, G_debug(), G_warning(), and NULL.

Referenced by V1_close_pg(), V1_delete_line_pg(), Vect__clean_grass_db_topo(), Vect__close_cursor_pg(), Vect__insert_face_pg(), Vect__open_cursor_next_line_pg(), and Vect_build_pg().

◆ Vect__open_cursor_line_pg()

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)

Fetch number of feature (given by CURSOR_PAGE) starting with fid.

Allocated cursor name should be freed by G_free().

Parameters

pg_info	pointer to Format_info_pg struct
fid	feature id to get
type	feature type

Returns: 0 on success; -1 on failure

Definition at line 1337 of file read_pg.c.

◆ Vect__open_cursor_next_line_pg()

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)

Allocated cursor name should be freed by G_free().

Parameters

	pg_info	pointer to Format_info_pg struct
	fetch_all	TRUE to fetch all records
[out]	cursor	name

Returns: 0 on success; -1 on failure

Definition at line 1234 of file read_pg.c.

References _, Format_info_pg::conn, Format_info_pg::cursor_name, DB_SQL_MAX, Format_info_pg::fid_column, G_asprintf(), G_debug(), G_free_tokens(), G_number_of_tokens(), G_tokenize(), G_warning(), Format_info_pg::geom_column, GV_BOUNDARY, GV_BUILD_CENTROIDS, GV_CENTROID, GV_LINE, GV_POINT, Format_info_pg::res, Format_info_pg::schema_name, Format_info_pg::table_name, Format_info_pg::topogeom_column, Format_info_pg::toposchema_name, Vect__execute_pg(), and Format_info_pg::where.

◆ Vect__reallocate_cache()

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

Reallocate lines cache.

Definition at line 1575 of file read_pg.c.

References G_realloc, Format_info_cache::lines, Format_info_cache::lines_alloc, Format_info_cache::lines_cats, Format_info_cache::lines_types, and Vect_new_line_struct().

◆ Vect__select_line_pg()

int Vect__select_line_pg	(	struct Format_info_pg *	pg_info,
		int	fid,
		int	type
	)

Select feature (internal use only)

Parameters

pg_info	pointer to Format_info_pg struct
fid	feature id to get
type	feature type

Returns: 0 on success; -1 on failure

Definition at line 1441 of file read_pg.c.

Functions

Detailed Description

Function Documentation

◆ get_feature()

◆ V1_read_line_pg()

◆ V1_read_next_line_pg()

◆ V2_read_line_pg()

◆ V2_read_next_line_pg()

◆ Vect__cache_feature_pg()

◆ Vect__close_cursor_pg()

◆ Vect__execute_get_value_pg()

◆ Vect__execute_pg()

◆ Vect__open_cursor_line_pg()

◆ Vect__open_cursor_next_line_pg()

◆ Vect__reallocate_cache()

◆ Vect__select_line_pg()