lwgeom_export.c

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/**********************************************************************
 *
 * PostGIS - Spatial Types for PostgreSQL
 * http://postgis.net
 *
 * PostGIS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * PostGIS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with PostGIS.  If not, see <http://www.gnu.org/licenses/>.
 *
 **********************************************************************
 *
 * Copyright 2009-2011 Olivier Courtin <olivier.courtin@oslandia.com>
 *
 **********************************************************************/
 
 
 
#include "postgres.h"
#include "catalog/pg_type.h" /* for INT4OID */
#include "executor/spi.h"
#include "utils/builtins.h"
#include "utils/jsonb.h"
 
#include "../postgis_config.h"
#include "lwgeom_cache.h"
#include "lwgeom_pg.h"
#include "liblwgeom.h"
#include "liblwgeom_internal.h"
 
Datum LWGEOM_asGML(PG_FUNCTION_ARGS);
Datum LWGEOM_asGeoJson(PG_FUNCTION_ARGS);
Datum LWGEOM_asGeoJson_old(PG_FUNCTION_ARGS);
Datum LWGEOM_asSVG(PG_FUNCTION_ARGS);
Datum LWGEOM_asX3D(PG_FUNCTION_ARGS);
Datum LWGEOM_asEncodedPolyline(PG_FUNCTION_ARGS);
Datum geometry_to_json(PG_FUNCTION_ARGS);
Datum geometry_to_jsonb(PG_FUNCTION_ARGS);
 
PG_FUNCTION_INFO_V1(LWGEOM_asGML);
Datum LWGEOM_asGML(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
        lwvarlena_t *v = NULL;
        int version;
        const char *srs;
        int32_t srid;
        int option = 0;
        int lwopts = LW_GML_IS_DIMS;
        int precision = OUT_DEFAULT_DECIMAL_DIGITS;
        static const char* default_prefix = "gml:"; /* default prefix */
        const char* prefix = default_prefix;
        const char* gml_id = NULL;
        size_t len;
        char *gml_id_buf, *prefix_buf;
        text *prefix_text, *gml_id_text;
 
        /*
         * Two potential callers, one starts with GML version,
         * one starts with geometry, and we check for initial
         * argument type and then dynamically change what args
         * we read based on presence/absence
         */
        Oid first_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
        int argnum = 0;
        if (first_type != INT4OID)
        {
                version = 2;
        }
        else
        {
                /* Get the version */
                version = PG_GETARG_INT32(argnum++);
                if (version != 2 && version != 3)
                {
                        elog(ERROR, "Only GML 2 and GML 3 are supported");
                        PG_RETURN_NULL();
                }
        }
 
        /* Get the geometry */
        if (PG_ARGISNULL(argnum))
                PG_RETURN_NULL();
        geom = PG_GETARG_GSERIALIZED_P(argnum++);
 
        /* Retrieve precision if any (default is max) */
        if (PG_NARGS() > argnum && !PG_ARGISNULL(argnum))
        {
                precision = PG_GETARG_INT32(argnum);
        }
        argnum++;
 
        /* retrieve option */
        if (PG_NARGS() > argnum && !PG_ARGISNULL(argnum))
                option = PG_GETARG_INT32(argnum);
        argnum++;
 
        /* retrieve prefix */
        if (PG_NARGS() > argnum && !PG_ARGISNULL(argnum))
        {
                prefix_text = PG_GETARG_TEXT_P(argnum);
                if ( VARSIZE(prefix_text) == VARHDRSZ )
                {
                        prefix = "";
                }
                else
                {
                        len = VARSIZE_ANY_EXHDR(prefix_text);
                        prefix_buf = palloc(len + 2); /* +2 is one for the ':' and one for term null */
                        memcpy(prefix_buf, VARDATA(prefix_text), len);
                        /* add colon and null terminate */
                        prefix_buf[len] = ':';
                        prefix_buf[len+1] = '\0';
                        prefix = prefix_buf;
                }
        }
        argnum++;
 
        if (PG_NARGS() > argnum && !PG_ARGISNULL(argnum))
        {
                gml_id_text = PG_GETARG_TEXT_P(argnum);
                if ( VARSIZE(gml_id_text) == VARHDRSZ )
                {
                        gml_id = "";
                }
                else
                {
                        len = VARSIZE_ANY_EXHDR(gml_id_text);
                        gml_id_buf = palloc(len+1);
                        memcpy(gml_id_buf, VARDATA(gml_id_text), len);
                        gml_id_buf[len] = '\0';
                        gml_id = gml_id_buf;
                }
        }
        argnum++;
 
        srid = gserialized_get_srid(geom);
        if (srid == SRID_UNKNOWN)      srs = NULL;
        else if (option & 1)
                srs = GetSRSCacheBySRID(fcinfo, srid, false);
        else
                srs = GetSRSCacheBySRID(fcinfo, srid, true);
 
        if (option & 2) lwopts &= ~LW_GML_IS_DIMS;
        if (option & 4) lwopts |= LW_GML_SHORTLINE;
        if (option & 8)
        {
                elog(ERROR,
                     "Options %d passed to ST_AsGML(geometry) sets "
                     "unsupported value 8",
                     option);
                PG_RETURN_NULL();
        }
        if (option & 16) lwopts |= LW_GML_IS_DEGREE;
        if (option & 32) lwopts |= LW_GML_EXTENT;
 
        lwgeom = lwgeom_from_gserialized(geom);
 
        if (version == 2)
        {
                if (lwopts & LW_GML_EXTENT)
                        v = lwgeom_extent_to_gml2(lwgeom, srs, precision, prefix);
                else
                        v = lwgeom_to_gml2(lwgeom, srs, precision, prefix);
        }
        if (version == 3)
        {
                if (lwopts & LW_GML_EXTENT)
                        v = lwgeom_extent_to_gml3(lwgeom, srs, precision, lwopts, prefix);
                else
                        v = lwgeom_to_gml3(lwgeom, srs, precision, lwopts, prefix, gml_id);
        }
 
        if (!v)
                PG_RETURN_NULL();
        PG_RETURN_TEXT_P(v);
}
 
 
PG_FUNCTION_INFO_V1(LWGEOM_asGeoJson);
Datum LWGEOM_asGeoJson(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
        int precision = OUT_DEFAULT_DECIMAL_DIGITS;
        int output_bbox = LW_FALSE;
        int output_long_crs = LW_FALSE;
        int output_short_crs = LW_FALSE;
        int output_guess_short_srid = LW_FALSE;
        const char *srs = NULL;
        int32_t srid;
 
        /* Get the geometry */
        if (PG_ARGISNULL(0))
                PG_RETURN_NULL();
 
        geom = PG_GETARG_GSERIALIZED_P(0);
        srid = gserialized_get_srid(geom);
 
        /* Retrieve precision if any (default is max) */
        if ( PG_NARGS() > 1 && !PG_ARGISNULL(1) )
        {
                precision = PG_GETARG_INT32(1);
        }
 
        /* Retrieve output option
         * 0 = without option
         * 1 = bbox
         * 2 = short crs
         * 4 = long crs
         * 8 = guess if CRS is needed (default)
         */
        if (PG_NARGS() > 2 && !PG_ARGISNULL(2))
        {
                int option = PG_GETARG_INT32(2);
                output_guess_short_srid = (option & 8) ? LW_TRUE : LW_FALSE;
                output_short_crs = (option & 2) ? LW_TRUE : LW_FALSE;
                output_long_crs = (option & 4) ? LW_TRUE : LW_FALSE;
                output_bbox = (option & 1) ? LW_TRUE : LW_FALSE;
        }
        else
                output_guess_short_srid = LW_TRUE;
 
        if (output_guess_short_srid && srid != WGS84_SRID && srid != SRID_UNKNOWN)
                output_short_crs = LW_TRUE;
 
        if (srid != SRID_UNKNOWN && (output_short_crs || output_long_crs))
        {
                srs = GetSRSCacheBySRID(fcinfo, srid, !output_long_crs);
 
                if (!srs)
                {
                        elog(ERROR, "SRID %i unknown in spatial_ref_sys table", srid);
                        PG_RETURN_NULL();
                }
        }
 
        lwgeom = lwgeom_from_gserialized(geom);
        PG_RETURN_TEXT_P(lwgeom_to_geojson(lwgeom, srs, precision, output_bbox));
}
 
 
PG_FUNCTION_INFO_V1(geometry_to_json);
Datum geometry_to_json(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        const char *srs = NULL;
        lwvarlena_t *geojson;
        if (lwgeom->srid != SRID_UNKNOWN)
        {
                const int short_crs = LW_TRUE;
                srs = GetSRSCacheBySRID(fcinfo, lwgeom->srid, short_crs);
        }
        geojson = lwgeom_to_geojson(lwgeom, srs, 15, 0);
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_TEXT_P(geojson);
}
 
PG_FUNCTION_INFO_V1(geometry_to_jsonb);
Datum geometry_to_jsonb(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
        const char *srs = NULL;
        lwvarlena_t *geojson;
        if (lwgeom->srid != SRID_UNKNOWN)
        {
                const int short_crs = LW_TRUE;
                srs = GetSRSCacheBySRID(fcinfo, lwgeom->srid, short_crs);
        }
        geojson = lwgeom_to_geojson(lwgeom, srs, 15, 0);
        lwgeom_free(lwgeom);
        PG_RETURN_DATUM(DirectFunctionCall1(jsonb_in, PointerGetDatum(pstrdup(geojson->data))));
}
 
 
PG_FUNCTION_INFO_V1(LWGEOM_asSVG);
Datum LWGEOM_asSVG(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
        int relative = 0;
        int precision = OUT_DEFAULT_DECIMAL_DIGITS;
 
        if ( PG_ARGISNULL(0) ) PG_RETURN_NULL();
 
        geom = PG_GETARG_GSERIALIZED_P(0);
 
        /* check for relative path notation */
        if ( PG_NARGS() > 1 && ! PG_ARGISNULL(1) )
                relative = PG_GETARG_INT32(1) ? 1:0;
 
        if ( PG_NARGS() > 2 && ! PG_ARGISNULL(2) )
        {
                precision = PG_GETARG_INT32(2);
        }
 
        lwgeom = lwgeom_from_gserialized(geom);
        PG_RETURN_TEXT_P(lwgeom_to_svg(lwgeom, precision, relative));
}
 
PG_FUNCTION_INFO_V1(LWGEOM_asX3D);
Datum LWGEOM_asX3D(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
        int version;
        int option = 0;
        int precision = OUT_DEFAULT_DECIMAL_DIGITS;
        static const char* default_defid = "x3d:"; /* default defid */
        char *defidbuf;
        const char* defid = default_defid;
        text *defid_text;
 
        /* Get the version */
        version = PG_GETARG_INT32(0);
        if (  version != 3 )
        {
                elog(ERROR, "Only X3D version 3 are supported");
                PG_RETURN_NULL();
        }
 
        /* Get the geometry */
        if ( PG_ARGISNULL(1) ) PG_RETURN_NULL();
        geom = PG_GETARG_GSERIALIZED_P(1);
 
        /* Retrieve precision if any (default is max) */
        if (PG_NARGS() >2 && !PG_ARGISNULL(2))
        {
                precision = PG_GETARG_INT32(2);
        }
 
        /* retrieve option */
        if (PG_NARGS() >3 && !PG_ARGISNULL(3))
                option = PG_GETARG_INT32(3);
 
 
        /* retrieve defid */
        if (PG_NARGS() >4 && !PG_ARGISNULL(4))
        {
                defid_text = PG_GETARG_TEXT_P(4);
                if ( VARSIZE_ANY_EXHDR(defid_text) == 0 )
                {
                        defid = "";
                }
                else
                {
                        /* +2 is one for the ':' and one for term null */
                        defidbuf = palloc(VARSIZE_ANY_EXHDR(defid_text)+2);
                        memcpy(defidbuf, VARDATA(defid_text),
                               VARSIZE_ANY_EXHDR(defid_text));
                        /* add colon and null terminate */
                        defidbuf[VARSIZE_ANY_EXHDR(defid_text)] = ':';
                        defidbuf[VARSIZE_ANY_EXHDR(defid_text)+1] = '\0';
                        defid = defidbuf;
                }
        }
 
        lwgeom = lwgeom_from_gserialized(geom);
 
        if (option & LW_X3D_USE_GEOCOORDS) {
                if (lwgeom->srid != 4326)
                {
                        PG_FREE_IF_COPY(geom, 0);
                        elog(ERROR, "Only SRID 4326 is supported for geocoordinates.");
                        PG_RETURN_NULL();
                }
        }
 
        PG_RETURN_TEXT_P(lwgeom_to_x3d3(lwgeom, precision, option, defid));
}
 
PG_FUNCTION_INFO_V1(LWGEOM_asEncodedPolyline);
Datum LWGEOM_asEncodedPolyline(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
        int precision = 5;
 
        if ( PG_ARGISNULL(0) ) PG_RETURN_NULL();
 
        geom = PG_GETARG_GSERIALIZED_P(0);
        if (gserialized_get_srid(geom) != 4326) {
                PG_FREE_IF_COPY(geom, 0);
                elog(ERROR, "Only SRID 4326 is supported.");
                PG_RETURN_NULL();
        }
        lwgeom = lwgeom_from_gserialized(geom);
 
        if (PG_NARGS() > 1 && !PG_ARGISNULL(1))
        {
                precision = PG_GETARG_INT32(1);
                if ( precision < 0 ) precision = 5;
        }
 
        PG_RETURN_TEXT_P(lwgeom_to_encoded_polyline(lwgeom, precision));
}