geography_inout.c

Go to the documentation of this file.

/**********************************************************************
 *
 * 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 Paul Ramsey <pramsey@cleverelephant.ca>
 *
 **********************************************************************/
 
 
#include "postgres.h"
 
#include "../postgis_config.h"
 
#include <math.h>
#include <float.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
 
#include "utils/elog.h"
#include "utils/array.h"
#include "utils/builtins.h"  /* for pg_atoi */
#include "lib/stringinfo.h"  /* For binary input */
#include "catalog/pg_type.h" /* for CSTRINGOID */
 
#include "liblwgeom.h"         /* For standard geometry types. */
#include "lwgeom_pg.h"       /* For debugging macros. */
#include "geography.h"       /* For utility functions. */
#include "lwgeom_export.h"   /* For export functions. */
#include "lwgeom_transform.h"
 
Datum geography_in(PG_FUNCTION_ARGS);
Datum geography_out(PG_FUNCTION_ARGS);
 
Datum geography_as_text(PG_FUNCTION_ARGS);
Datum geography_from_text(PG_FUNCTION_ARGS);
Datum geography_as_geojson(PG_FUNCTION_ARGS);
Datum geography_as_gml(PG_FUNCTION_ARGS);
Datum geography_as_kml(PG_FUNCTION_ARGS);
Datum geography_as_svg(PG_FUNCTION_ARGS);
Datum geography_from_binary(PG_FUNCTION_ARGS);
Datum geography_from_geometry(PG_FUNCTION_ARGS);
Datum geometry_from_geography(PG_FUNCTION_ARGS);
Datum geography_send(PG_FUNCTION_ARGS);
Datum geography_recv(PG_FUNCTION_ARGS);
 
GSERIALIZED* gserialized_geography_from_lwgeom(LWGEOM *lwgeom, int32 geog_typmod);
 
void geography_valid_type(uint8_t type)
{
        if ( ! (
                    type == POINTTYPE ||
                    type == LINETYPE ||
                    type == POLYGONTYPE ||
                    type == MULTIPOINTTYPE ||
                    type == MULTILINETYPE ||
                    type == MULTIPOLYGONTYPE ||
                    type == COLLECTIONTYPE
                ) )
        {
                ereport(ERROR, (
                            errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                            errmsg("Geography type does not support %s", lwtype_name(type) )));
 
        }
}
 
GSERIALIZED* gserialized_geography_from_lwgeom(LWGEOM *lwgeom, int32 geog_typmod)
{
        GSERIALIZED *g_ser = NULL;
 
        /* Set geodetic flag */
        lwgeom_set_geodetic(lwgeom, true);
 
        /* Check that this is a type we can handle */
        geography_valid_type(lwgeom->type);
 
        /* Force the geometry to have valid geodetic coordinate range. */
        lwgeom_nudge_geodetic(lwgeom);
        if ( lwgeom_force_geodetic(lwgeom) == LW_TRUE )
        {
                ereport(NOTICE, (
                        errmsg_internal("Coordinate values were coerced into range [-180 -90, 180 90] for GEOGRAPHY" ))
                );
        }
 
        /* Force default SRID to the default */
        if ( (int)lwgeom->srid <= 0 )
                lwgeom->srid = SRID_DEFAULT;
 
        /*
        ** Serialize our lwgeom and set the geodetic flag so subsequent
        ** functions do the right thing.
        */
        g_ser = geography_serialize(lwgeom);
 
        /* Check for typmod agreement */
        if ( geog_typmod >= 0 )
        {
                g_ser = postgis_valid_typmod(g_ser, geog_typmod);
                POSTGIS_DEBUG(3, "typmod and geometry were consistent");
        }
        else
        {
                POSTGIS_DEBUG(3, "typmod was -1");
        }
 
        return g_ser;
}
 
 
/*
** geography_in(cstring) returns *GSERIALIZED
*/
PG_FUNCTION_INFO_V1(geography_in);
Datum geography_in(PG_FUNCTION_ARGS)
{
        char *str = PG_GETARG_CSTRING(0);
        /* Datum geog_oid = PG_GETARG_OID(1); Not needed. */
        int32 geog_typmod = -1;
        LWGEOM_PARSER_RESULT lwg_parser_result;
        LWGEOM *lwgeom = NULL;
        GSERIALIZED *g_ser = NULL;
 
        if ( (PG_NARGS()>2) && (!PG_ARGISNULL(2)) ) {
                geog_typmod = PG_GETARG_INT32(2);
        }
 
        lwgeom_parser_result_init(&lwg_parser_result);
 
        /* Empty string. */
        if ( str[0] == '\0' )
                ereport(ERROR,(errmsg("parse error - invalid geometry")));
 
        /* WKB? Let's find out. */
        if ( str[0] == '0' )
        {
                /* TODO: 20101206: No parser checks! This is inline with current 1.5 behavior, but needs discussion */
                lwgeom = lwgeom_from_hexwkb(str, LW_PARSER_CHECK_NONE);
                /* Error out if something went sideways */
                if ( ! lwgeom )
                        ereport(ERROR,(errmsg("parse error - invalid geometry")));
        }
        /* WKT then. */
        else
        {
                if ( lwgeom_parse_wkt(&lwg_parser_result, str, LW_PARSER_CHECK_ALL) == LW_FAILURE )
                        PG_PARSER_ERROR(lwg_parser_result);
 
                lwgeom = lwg_parser_result.geom;
        }
 
        /* Error on any SRID != default */
        srid_is_latlong(fcinfo, lwgeom->srid);
 
        /* Convert to gserialized */
        g_ser = gserialized_geography_from_lwgeom(lwgeom, geog_typmod);
 
        /* Clean up temporary object */
        lwgeom_free(lwgeom);
 
 
        PG_RETURN_POINTER(g_ser);
}
 
/*
** geography_out(*GSERIALIZED) returns cstring
*/
PG_FUNCTION_INFO_V1(geography_out);
Datum geography_out(PG_FUNCTION_ARGS)
{
        LWGEOM *lwgeom = NULL;
        GSERIALIZED *g = NULL;
        char *hexwkb;
 
        g = PG_GETARG_GSERIALIZED_P(0);
        lwgeom = lwgeom_from_gserialized(g);
        hexwkb = lwgeom_to_hexwkb(lwgeom, WKB_EXTENDED, 0);
        lwgeom_free(lwgeom);
 
        PG_RETURN_CSTRING(hexwkb);
}
 
 
/*
** geography_as_gml(*GSERIALIZED) returns text
*/
PG_FUNCTION_INFO_V1(geography_as_gml);
Datum geography_as_gml(PG_FUNCTION_ARGS)
{
        LWGEOM *lwgeom = NULL;
        GSERIALIZED *g = NULL;
        char *gml;
        text *result;
        int version;
        char *srs;
        int srid = SRID_DEFAULT;
        int precision = DBL_DIG;
        int option = 0;
        int lwopts = LW_GML_IS_DIMS;
        static const char *default_prefix = "gml:";
        const char *prefix = default_prefix;
        char *prefix_buf = "";
        text *prefix_text, *id_text = NULL;
        const char *id=NULL;
        char *id_buf;
 
 
        /* Get the version */
        version = PG_GETARG_INT32(0);
        if ( version != 2 && version != 3 )
        {
                elog(ERROR, "Only GML 2 and GML 3 are supported");
                PG_RETURN_NULL();
        }
 
        /* Get the geography */
        if ( PG_ARGISNULL(1) ) PG_RETURN_NULL();
        g = PG_GETARG_GSERIALIZED_P(1);
 
        /* Convert to lwgeom so we can run the old functions */
        lwgeom = lwgeom_from_gserialized(g);
 
        /* Retrieve precision if any (default is max) */
        if (PG_NARGS() >2 && !PG_ARGISNULL(2))
        {
                precision = PG_GETARG_INT32(2);
                /* TODO: leave this to liblwgeom */
                if ( precision > DBL_DIG )
                        precision = DBL_DIG;
                else if ( precision < 0 ) precision = 0;
        }
 
        /* retrieve option */
        if (PG_NARGS() >3 && !PG_ARGISNULL(3))
                option = PG_GETARG_INT32(3);
 
 
        /* retrieve prefix */
        if (PG_NARGS() >4 && !PG_ARGISNULL(4))
        {
                prefix_text = PG_GETARG_TEXT_P(4);
                if ( VARSIZE(prefix_text)-VARHDRSZ == 0 )
                {
                        prefix = "";
                }
                else
                {
                        /* +2 is one for the ':' and one for term null */
                        prefix_buf = palloc(VARSIZE(prefix_text)-VARHDRSZ+2);
                        memcpy(prefix_buf, VARDATA(prefix_text),
                               VARSIZE(prefix_text)-VARHDRSZ);
                        /* add colon and null terminate */
                        prefix_buf[VARSIZE(prefix_text)-VARHDRSZ] = ':';
                        prefix_buf[VARSIZE(prefix_text)-VARHDRSZ+1] = '\0';
                        prefix = prefix_buf;
                }
        }
 
        /* retrieve id */
        if (PG_NARGS() >5 && !PG_ARGISNULL(5))
        {
                id_text = PG_GETARG_TEXT_P(5);
                if ( VARSIZE(id_text)-VARHDRSZ == 0 )
                {
                        id = "";
                }
                else
                {
                        id_buf = palloc(VARSIZE(id_text)-VARHDRSZ+1);
                        memcpy(id_buf, VARDATA(id_text), VARSIZE(id_text)-VARHDRSZ);
                        prefix_buf[VARSIZE(id_text)-VARHDRSZ+1] = '\0';
                        id = id_buf;
                }
        }
 
        if (option & 1)
                srs = getSRSbySRID(fcinfo, srid, false);
        else
                srs = getSRSbySRID(fcinfo, srid, true);
        if (!srs)
        {
                elog(ERROR, "SRID %d unknown in spatial_ref_sys table", SRID_DEFAULT);
                PG_RETURN_NULL();
        }
 
        /* Revert lat/lon only with long SRS */
        if (option & 1) lwopts |= LW_GML_IS_DEGREE;
        if (option & 2) lwopts &= ~LW_GML_IS_DIMS;
        if (option & 8)
        {
                elog(ERROR,
                     "Options %d passed to ST_AsGML(geography) sets "
                     "unsupported value 8",
                     option);
                PG_RETURN_NULL();
        }
        if ((option & 4) || (option & 16) || (option & 32))
        {
                elog(ERROR,
                     "Options %d passed to ST_AsGML(geography) but are only "
                     "applicable to ST_AsGML(geometry)",
                     option);
                PG_RETURN_NULL();
        }
 
        if (version == 2)
                gml = lwgeom_to_gml2(lwgeom, srs, precision, prefix);
        else
                gml = lwgeom_to_gml3(lwgeom, srs, precision, lwopts, prefix, id);
 
    lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(g, 1);
 
        /* Return null on null */
        if ( ! gml )
                PG_RETURN_NULL();
 
        /* Turn string result into text for return */
        result = cstring_to_text(gml);
        lwfree(gml);
 
        PG_RETURN_TEXT_P(result);
}
 
 
/*
** geography_as_kml(*GSERIALIZED) returns text
*/
PG_FUNCTION_INFO_V1(geography_as_kml);
Datum geography_as_kml(PG_FUNCTION_ARGS)
{
        GSERIALIZED *g = NULL;
        LWGEOM *lwgeom = NULL;
        char *kml;
        text *result;
        int version;
        int precision = DBL_DIG;
        static const char *default_prefix = "";
        char *prefixbuf;
        const char* prefix = default_prefix;
        text *prefix_text;
 
 
        /* Get the version */
        version = PG_GETARG_INT32(0);
        if ( version != 2)
        {
                elog(ERROR, "Only KML 2 is supported");
                PG_RETURN_NULL();
        }
 
        /* Get the geometry */
        if ( PG_ARGISNULL(1) ) PG_RETURN_NULL();
        g = PG_GETARG_GSERIALIZED_P(1);
 
        /* Convert to lwgeom so we can run the old functions */
        lwgeom = lwgeom_from_gserialized(g);
 
        /* Retrieve precision if any (default is max) */
        if (PG_NARGS() >2 && !PG_ARGISNULL(2))
        {
                precision = PG_GETARG_INT32(2);
                /* TODO: leave this to liblwgeom */
                if ( precision > DBL_DIG )
                        precision = DBL_DIG;
                else if ( precision < 0 ) precision = 0;
        }
 
        /* retrieve prefix */
        if (PG_NARGS() >3 && !PG_ARGISNULL(3))
        {
                prefix_text = PG_GETARG_TEXT_P(3);
                if ( VARSIZE(prefix_text)-VARHDRSZ == 0 )
                {
                        prefix = "";
                }
                else
                {
                        /* +2 is one for the ':' and one for term null */
                        prefixbuf = palloc(VARSIZE(prefix_text)-VARHDRSZ+2);
                        memcpy(prefixbuf, VARDATA(prefix_text),
                               VARSIZE(prefix_text)-VARHDRSZ);
                        /* add colon and null terminate */
                        prefixbuf[VARSIZE(prefix_text)-VARHDRSZ] = ':';
                        prefixbuf[VARSIZE(prefix_text)-VARHDRSZ+1] = '\0';
                        prefix = prefixbuf;
                }
        }
 
        kml = lwgeom_to_kml2(lwgeom, precision, prefix);
 
    lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(g, 1);
 
        if ( ! kml )
                PG_RETURN_NULL();
 
        result = cstring_to_text(kml);
        lwfree(kml);
 
        PG_RETURN_TEXT_P(result);
}
 
 
/*
** geography_as_svg(*GSERIALIZED) returns text
*/
PG_FUNCTION_INFO_V1(geography_as_svg);
Datum geography_as_svg(PG_FUNCTION_ARGS)
{
        GSERIALIZED *g = NULL;
        LWGEOM *lwgeom = NULL;
        char *svg;
        text *result;
        int relative = 0;
        int precision=DBL_DIG;
 
        if ( PG_ARGISNULL(0) ) PG_RETURN_NULL();
 
        g = PG_GETARG_GSERIALIZED_P(0);
 
        /* Convert to lwgeom so we can run the old functions */
        lwgeom = lwgeom_from_gserialized(g);
 
        /* 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);
                /* TODO: leave this to liblwgeom */
                if ( precision > DBL_DIG )
                        precision = DBL_DIG;
                else if ( precision < 0 ) precision = 0;
        }
 
        svg = lwgeom_to_svg(lwgeom, precision, relative);
 
    lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(g, 0);
 
        result = cstring_to_text(svg);
        lwfree(svg);
 
        PG_RETURN_TEXT_P(result);
}
 
 
/*
** geography_as_geojson(*GSERIALIZED) returns text
*/
PG_FUNCTION_INFO_V1(geography_as_geojson);
Datum geography_as_geojson(PG_FUNCTION_ARGS)
{
        LWGEOM *lwgeom = NULL;
        GSERIALIZED *g = NULL;
        char *geojson;
        text *result;
        int version;
        int option = 0;
        int has_bbox = 0;
        int precision = DBL_DIG;
        char * srs = NULL;
 
        /* Get the version */
        version = PG_GETARG_INT32(0);
        if ( version != 1)
        {
                elog(ERROR, "Only GeoJSON 1 is supported");
                PG_RETURN_NULL();
        }
 
        /* Get the geography */
        if (PG_ARGISNULL(1) ) PG_RETURN_NULL();
        g = PG_GETARG_GSERIALIZED_P(1);
 
        /* Convert to lwgeom so we can run the old functions */
        lwgeom = lwgeom_from_gserialized(g);
 
        /* Retrieve precision if any (default is max) */
        if (PG_NARGS() >2 && !PG_ARGISNULL(2))
        {
                precision = PG_GETARG_INT32(2);
                /* TODO: leave this to liblwgeom */
                if ( precision > DBL_DIG )
                        precision = DBL_DIG;
                else if ( precision < 0 ) precision = 0;
        }
 
        /* Retrieve output option
         * 0 = without option (default)
         * 1 = bbox
         * 2 = short crs
         * 4 = long crs
         */
        if (PG_NARGS() >3 && !PG_ARGISNULL(3))
                option = PG_GETARG_INT32(3);
 
        if (option & 2 || option & 4)
        {
                /* Geography only handle srid SRID_DEFAULT */
                if (option & 2)
                        srs = getSRSbySRID(fcinfo, SRID_DEFAULT, true);
                if (option & 4)
                        srs = getSRSbySRID(fcinfo, SRID_DEFAULT, false);
 
                if (!srs)
                {
                        elog(ERROR, "SRID SRID_DEFAULT unknown in spatial_ref_sys table");
                        PG_RETURN_NULL();
                }
        }
 
        if (option & 1) has_bbox = 1;
 
        geojson = lwgeom_to_geojson(lwgeom, srs, precision, has_bbox);
    lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(g, 1);
        if (srs) pfree(srs);
 
        result = cstring_to_text(geojson);
        lwfree(geojson);
 
        PG_RETURN_TEXT_P(result);
}
 
 
/*
** geography_from_text(*char) returns *GSERIALIZED
**
** Convert text (varlena) to cstring and then call geography_in().
*/
PG_FUNCTION_INFO_V1(geography_from_text);
Datum geography_from_text(PG_FUNCTION_ARGS)
{
        LWGEOM_PARSER_RESULT lwg_parser_result;
        GSERIALIZED *g_ser = NULL;
        text *wkt_text = PG_GETARG_TEXT_P(0);
 
        /* Extract the cstring from the varlena */
        char *wkt = text_to_cstring(wkt_text);
 
        /* Pass the cstring to the input parser, and magic occurs! */
        if ( lwgeom_parse_wkt(&lwg_parser_result, wkt, LW_PARSER_CHECK_ALL) == LW_FAILURE )
                PG_PARSER_ERROR(lwg_parser_result);
 
        /* Error on any SRID != default */
        srid_is_latlong(fcinfo, lwg_parser_result.geom->srid);
 
        /* Clean up string */
        pfree(wkt);
        g_ser = gserialized_geography_from_lwgeom(lwg_parser_result.geom, -1);
 
        /* Clean up temporary object */
        lwgeom_free(lwg_parser_result.geom);
 
        PG_RETURN_POINTER(g_ser);
}
 
/*
** geography_from_binary(*char) returns *GSERIALIZED
*/
PG_FUNCTION_INFO_V1(geography_from_binary);
Datum geography_from_binary(PG_FUNCTION_ARGS)
{
        char *wkb_bytea = (char*)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
        GSERIALIZED *gser = NULL;
        size_t wkb_size = VARSIZE(wkb_bytea);
        uint8_t *wkb = (uint8_t*)VARDATA(wkb_bytea);
        LWGEOM *lwgeom = lwgeom_from_wkb(wkb, wkb_size, LW_PARSER_CHECK_NONE);
 
        if ( ! lwgeom )
                lwpgerror("Unable to parse WKB");
 
        /* Error on any SRID != default */
        srid_is_latlong(fcinfo, lwgeom->srid);
 
        gser = gserialized_geography_from_lwgeom(lwgeom, -1);
        lwgeom_free(lwgeom);
        PG_RETURN_POINTER(gser);
}
 
 
PG_FUNCTION_INFO_V1(geography_from_geometry);
Datum geography_from_geometry(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P_COPY(0);
        LWGEOM *lwgeom = NULL;
        GSERIALIZED *g_ser = NULL;
 
        geography_valid_type(gserialized_get_type(geom));
 
        lwgeom = lwgeom_from_gserialized(geom);
 
        /* Force default SRID */
        if ( (int)lwgeom->srid <= 0 )
        {
                lwgeom->srid = SRID_DEFAULT;
        }
 
        /* Error on any SRID != default */
        srid_is_latlong(fcinfo, lwgeom->srid);
 
        /* Force the geometry to have valid geodetic coordinate range. */
        lwgeom_nudge_geodetic(lwgeom);
        if ( lwgeom_force_geodetic(lwgeom) == LW_TRUE )
        {
                ereport(NOTICE, (
                        errmsg_internal("Coordinate values were coerced into range [-180 -90, 180 90] for GEOGRAPHY" ))
                );
        }
 
        /* force recalculate of box by dropping */
        lwgeom_drop_bbox(lwgeom);
 
        lwgeom_set_geodetic(lwgeom, true);
        /* We are trusting geography_serialize will add a box if needed */
        g_ser = geography_serialize(lwgeom);
 
 
        lwgeom_free(lwgeom);
 
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_POINTER(g_ser);
}
 
PG_FUNCTION_INFO_V1(geometry_from_geography);
Datum geometry_from_geography(PG_FUNCTION_ARGS)
{
        LWGEOM *lwgeom = NULL;
        GSERIALIZED *ret = NULL;
        GSERIALIZED *g_ser = PG_GETARG_GSERIALIZED_P(0);
 
        lwgeom = lwgeom_from_gserialized(g_ser);
 
        /* Recalculate the boxes after re-setting the geodetic bit */
        lwgeom_set_geodetic(lwgeom, false);
        lwgeom_refresh_bbox(lwgeom);
 
        /* We want "geometry" to think all our "geography" has an SRID, and the
           implied SRID is the default, so we fill that in if our SRID is actually unknown. */
        if ( (int)lwgeom->srid <= 0 )
                lwgeom->srid = SRID_DEFAULT;
 
        ret = geometry_serialize(lwgeom);
        lwgeom_free(lwgeom);
 
        PG_RETURN_POINTER(ret);
}
 
PG_FUNCTION_INFO_V1(geography_recv);
Datum geography_recv(PG_FUNCTION_ARGS)
{
        StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
        int32 geog_typmod = -1;
        LWGEOM *lwgeom = NULL;
        GSERIALIZED *g_ser = NULL;
 
        if ( (PG_NARGS()>2) && (!PG_ARGISNULL(2)) ) {
                geog_typmod = PG_GETARG_INT32(2);
        }
 
        lwgeom = lwgeom_from_wkb((uint8_t*)buf->data, buf->len, LW_PARSER_CHECK_ALL);
 
        /* Error on any SRID != default */
        srid_is_latlong(fcinfo, lwgeom->srid);
 
        g_ser = gserialized_geography_from_lwgeom(lwgeom, geog_typmod);
 
        /* Clean up temporary object */
        lwgeom_free(lwgeom);
 
        /* Set cursor to the end of buffer (so the backend is happy) */
        buf->cursor = buf->len;
 
        PG_RETURN_POINTER(g_ser);
}
 
 
PG_FUNCTION_INFO_V1(geography_send);
Datum geography_send(PG_FUNCTION_ARGS)
{
        LWGEOM *lwgeom = NULL;
        GSERIALIZED *g = NULL;
        size_t size_result;
        uint8_t *wkb;
        bytea *result;
 
        g = PG_GETARG_GSERIALIZED_P(0);
        lwgeom = lwgeom_from_gserialized(g);
        wkb = lwgeom_to_wkb(lwgeom, WKB_EXTENDED, &size_result);
        lwgeom_free(lwgeom);
 
        result = palloc(size_result + VARHDRSZ);
        SET_VARSIZE(result, size_result + VARHDRSZ);
        memcpy(VARDATA(result), wkb, size_result);
        pfree(wkb);
 
        PG_RETURN_POINTER(result);
}