lwgeom_inout.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^
 *
 **********************************************************************/

#include "postgres.h"

#include "../postgis_config.h"

#include <math.h>
#include <float.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <assert.h>

#include "access/gist.h"
#include "access/itup.h"

#include "fmgr.h"
#include "utils/elog.h"
#include "mb/pg_wchar.h"
# include "lib/stringinfo.h" /* for binary input */
#include "utils/array.h"
#include "utils/lsyscache.h"
#include "funcapi.h"

#include "liblwgeom.h"
#include "lwgeom_pg.h"
#include "geography.h" /* for lwgeom_valid_typmod */
#include "lwgeom_transform.h"


#include "access/htup_details.h"


void elog_ERROR(const char* string);

Datum LWGEOM_in(PG_FUNCTION_ARGS);
Datum LWGEOM_out(PG_FUNCTION_ARGS);
Datum LWGEOM_to_text(PG_FUNCTION_ARGS);
Datum LWGEOM_to_bytea(PG_FUNCTION_ARGS);
Datum LWGEOM_from_bytea(PG_FUNCTION_ARGS);
Datum LWGEOM_asHEXEWKB(PG_FUNCTION_ARGS);
Datum parse_WKT_lwgeom(PG_FUNCTION_ARGS);
Datum LWGEOM_recv(PG_FUNCTION_ARGS);
Datum LWGEOM_send(PG_FUNCTION_ARGS);
Datum LWGEOM_to_latlon(PG_FUNCTION_ARGS);
Datum WKBFromLWGEOM(PG_FUNCTION_ARGS);
Datum TWKBFromLWGEOM(PG_FUNCTION_ARGS);
Datum TWKBFromLWGEOMArray(PG_FUNCTION_ARGS);
Datum LWGEOMFromTWKB(PG_FUNCTION_ARGS);


/*
 * LWGEOM_in(cstring)
 * format is '[SRID=#;]wkt|wkb'
 *  LWGEOM_in( 'SRID=99;POINT(0 0)')
 *  LWGEOM_in( 'POINT(0 0)')            --> assumes SRID=SRID_UNKNOWN
 *  LWGEOM_in( 'SRID=99;0101000000000000000000F03F000000000000004')
 *  LWGEOM_in( '0101000000000000000000F03F000000000000004')
 *  returns a GSERIALIZED object
 */
PG_FUNCTION_INFO_V1(LWGEOM_in);
Datum LWGEOM_in(PG_FUNCTION_ARGS)
{
        char *input = PG_GETARG_CSTRING(0);
        int32 geom_typmod = -1;
        char *str = input;
        LWGEOM_PARSER_RESULT lwg_parser_result;
        LWGEOM *lwgeom;
        GSERIALIZED *ret;
        int srid = 0;

        if ( (PG_NARGS()>2) && (!PG_ARGISNULL(2)) ) {
                geom_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")));
                PG_RETURN_NULL();
        }

        /* Starts with "SRID=" */
        if( strncasecmp(str,"SRID=",5) == 0 )
        {
                /* Roll forward to semi-colon */
                char *tmp = str;
                while ( tmp && *tmp != ';' )
                        tmp++;

                /* Check next character to see if we have WKB  */
                if ( tmp && *(tmp+1) == '0' )
                {
                        /* Null terminate the SRID= string */
                        *tmp = '\0';
                        /* Set str to the start of the real WKB */
                        str = tmp + 1;
                        /* Move tmp to the start of the numeric part */
                        tmp = input + 5;
                        /* Parse out the SRID number */
                        srid = atoi(tmp);
                }
        }

        /* WKB? Let's find out. */
        if ( str[0] == '0' )
        {
                size_t hexsize = strlen(str);
                unsigned char *wkb = bytes_from_hexbytes(str, hexsize);
                /* TODO: 20101206: No parser checks! This is inline with current 1.5 behavior, but needs discussion */
                lwgeom = lwgeom_from_wkb(wkb, hexsize/2, LW_PARSER_CHECK_NONE);
                /* If we picked up an SRID at the head of the WKB set it manually */
                if ( srid ) lwgeom_set_srid(lwgeom, srid);
                /* Add a bbox if necessary */
                if ( lwgeom_needs_bbox(lwgeom) ) lwgeom_add_bbox(lwgeom);
                pfree(wkb);
                ret = geometry_serialize(lwgeom);
                lwgeom_free(lwgeom);
        }
        /* WKT then. */
        else
        {
                if ( lwgeom_parse_wkt(&lwg_parser_result, str, LW_PARSER_CHECK_ALL) == LW_FAILURE )
                {
                        PG_PARSER_ERROR(lwg_parser_result);
                        PG_RETURN_NULL();
                }
                lwgeom = lwg_parser_result.geom;
                if ( lwgeom_needs_bbox(lwgeom) )
                        lwgeom_add_bbox(lwgeom);
                ret = geometry_serialize(lwgeom);
                lwgeom_parser_result_free(&lwg_parser_result);
        }

        if ( geom_typmod >= 0 )
        {
                ret = postgis_valid_typmod(ret, geom_typmod);
                POSTGIS_DEBUG(3, "typmod and geometry were consistent");
        }
        else
        {
                POSTGIS_DEBUG(3, "typmod was -1");
        }

        /* Don't free the parser result (and hence lwgeom) until we have done */
        /* the typemod check with lwgeom */

        PG_RETURN_POINTER(ret);

}

/*
 * LWGEOM_to_latlon(GEOMETRY, text)
 *  NOTE: Geometry must be a point.  It is assumed that the coordinates
 *        of the point are in a lat/lon projection, and they will be
 *        normalized in the output to -90-90 and -180-180.
 *
 *  The text parameter is a format string containing the format for the
 *  resulting text, similar to a date format string.  Valid tokens
 *  are "D" for degrees, "M" for minutes, "S" for seconds, and "C" for
 *  cardinal direction (NSEW).  DMS tokens may be repeated to indicate
 *  desired width and precision ("SSS.SSSS" means "  1.0023").
 *  "M", "S", and "C" are optional.  If "C" is omitted, degrees are
 *  shown with a "-" sign if south or west.  If "S" is omitted,
 *  minutes will be shown as decimal with as many digits of precision
 *  as you specify.  If "M" is omitted, degrees are shown as decimal
 *  with as many digits precision as you specify.
 *
 *  If the format string is omitted (null or 0-length) a default
 *  format will be used.
 *
 *  returns text
 */
PG_FUNCTION_INFO_V1(LWGEOM_to_latlon);
Datum LWGEOM_to_latlon(PG_FUNCTION_ARGS)
{
        /* Get the parameters */
        GSERIALIZED *pg_lwgeom = PG_GETARG_GSERIALIZED_P(0);
        text *format_text = PG_GETARG_TEXT_P(1);

        LWGEOM *lwgeom;
        char *format_str = NULL;

        char * formatted_str;
        text * formatted_text;
        char * tmp;

        /* Only supports points. */
        uint8_t geom_type = gserialized_get_type(pg_lwgeom);
        if (POINTTYPE != geom_type)
        {
                lwpgerror("Only points are supported, you tried type %s.", lwtype_name(geom_type));
        }
        /* Convert to LWGEOM type */
        lwgeom = lwgeom_from_gserialized(pg_lwgeom);

  if (format_text == NULL) {
    lwpgerror("ST_AsLatLonText: invalid format string (null");
    PG_RETURN_NULL();
  }

        format_str = text2cstring(format_text);
  assert(format_str != NULL);

  /* The input string supposedly will be in the database encoding,
     so convert to UTF-8. */
  tmp = (char *)pg_do_encoding_conversion(
    (uint8_t *)format_str, strlen(format_str), GetDatabaseEncoding(), PG_UTF8);
  assert(tmp != NULL);
  if ( tmp != format_str ) {
    pfree(format_str);
    format_str = tmp;
  }

        /* Produce the formatted string. */
        formatted_str = lwpoint_to_latlon((LWPOINT *)lwgeom, format_str);
  assert(formatted_str != NULL);
  pfree(format_str);

  /* Convert the formatted string from UTF-8 back to database encoding. */
  tmp = (char *)pg_do_encoding_conversion(
    (uint8_t *)formatted_str, strlen(formatted_str),
    PG_UTF8, GetDatabaseEncoding());
  assert(tmp != NULL);
  if ( tmp != formatted_str) {
    pfree(formatted_str);
    formatted_str = tmp;
  }

        /* Convert to the postgres output string type. */
        formatted_text = cstring2text(formatted_str);
  pfree(formatted_str);

        PG_RETURN_POINTER(formatted_text);
}

/*
 * LWGEOM_out(lwgeom) --> cstring
 * output is 'SRID=#;<wkb in hex form>'
 * ie. 'SRID=-99;0101000000000000000000F03F0000000000000040'
 * WKB is machine endian
 * if SRID=-1, the 'SRID=-1;' will probably not be present.
 */
PG_FUNCTION_INFO_V1(LWGEOM_out);
Datum LWGEOM_out(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom;
        char *hexwkb;
        size_t hexwkb_size;

        lwgeom = lwgeom_from_gserialized(geom);
        hexwkb = lwgeom_to_hexwkb(lwgeom, WKB_EXTENDED, &hexwkb_size);
        lwgeom_free(lwgeom);

        PG_RETURN_CSTRING(hexwkb);
}

/*
 * AsHEXEWKB(geom, string)
 */
PG_FUNCTION_INFO_V1(LWGEOM_asHEXEWKB);
Datum LWGEOM_asHEXEWKB(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom;
        char *hexwkb;
        size_t hexwkb_size;
        uint8_t variant = 0;
        text *result;
        text *type;
        size_t text_size;

        /* If user specified endianness, respect it */
        if ( (PG_NARGS()>1) && (!PG_ARGISNULL(1)) )
        {
                type = PG_GETARG_TEXT_P(1);

                if  ( ! strncmp(VARDATA(type), "xdr", 3) ||
                      ! strncmp(VARDATA(type), "XDR", 3) )
                {
                        variant = variant | WKB_XDR;
                }
                else
                {
                        variant = variant | WKB_NDR;
                }
        }

        /* Create WKB hex string */
        lwgeom = lwgeom_from_gserialized(geom);
        hexwkb = lwgeom_to_hexwkb(lwgeom, variant | WKB_EXTENDED, &hexwkb_size);
        lwgeom_free(lwgeom);

        /* Prepare the PgSQL text return type */
        text_size = hexwkb_size - 1 + VARHDRSZ;
        result = palloc(text_size);
        memcpy(VARDATA(result), hexwkb, hexwkb_size - 1);
        SET_VARSIZE(result, text_size);

        /* Clean up and return */
        pfree(hexwkb);
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_TEXT_P(result);
}


/*
 * LWGEOM_to_text(lwgeom) --> text
 * output is 'SRID=#;<wkb in hex form>'
 * ie. 'SRID=-99;0101000000000000000000F03F0000000000000040'
 * WKB is machine endian
 * if SRID=-1, the 'SRID=-1;' will probably not be present.
 */
PG_FUNCTION_INFO_V1(LWGEOM_to_text);
Datum LWGEOM_to_text(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom;
        char *hexwkb;
        size_t hexwkb_size;
        text *result;

        /* Generate WKB hex text */
        lwgeom = lwgeom_from_gserialized(geom);
        hexwkb = lwgeom_to_hexwkb(lwgeom, WKB_EXTENDED, &hexwkb_size);
        lwgeom_free(lwgeom);

        /* Copy into text obect */
        result = cstring2text(hexwkb);
        pfree(hexwkb);

        /* Clean up and return */
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_TEXT_P(result);
}

/*
 * LWGEOMFromEWKB(wkb,  [SRID] )
 * NOTE: wkb is in *binary* not hex form.
 *
 * NOTE: this function parses EWKB (extended form)
 *       which also contains SRID info.
 */
PG_FUNCTION_INFO_V1(LWGEOMFromEWKB);
Datum LWGEOMFromEWKB(PG_FUNCTION_ARGS)
{
        bytea *bytea_wkb = (bytea*)PG_GETARG_BYTEA_P(0);
        int32 srid = 0;
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
        uint8_t *wkb = (uint8_t*)VARDATA(bytea_wkb);

        lwgeom = lwgeom_from_wkb(wkb, VARSIZE(bytea_wkb)-VARHDRSZ, LW_PARSER_CHECK_ALL);

        if (  ( PG_NARGS()>1) && ( ! PG_ARGISNULL(1) ))
        {
                srid = PG_GETARG_INT32(1);
                lwgeom_set_srid(lwgeom, srid);
        }

        if ( lwgeom_needs_bbox(lwgeom) )
                lwgeom_add_bbox(lwgeom);

        geom = geometry_serialize(lwgeom);
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(bytea_wkb, 0);
        PG_RETURN_POINTER(geom);
}
/*
 * LWGEOMFromTWKB(wkb)
 * NOTE: twkb is in *binary* not hex form.
 *
 */
PG_FUNCTION_INFO_V1(LWGEOMFromTWKB);
Datum LWGEOMFromTWKB(PG_FUNCTION_ARGS)
{
        bytea *bytea_twkb = (bytea*)PG_GETARG_BYTEA_P(0);
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
        uint8_t *twkb = (uint8_t*)VARDATA(bytea_twkb);

        lwgeom = lwgeom_from_twkb(twkb, VARSIZE(bytea_twkb)-VARHDRSZ, LW_PARSER_CHECK_ALL);

        if ( lwgeom_needs_bbox(lwgeom) )
                lwgeom_add_bbox(lwgeom);

        geom = geometry_serialize(lwgeom);
        lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(bytea_twkb, 0);
        PG_RETURN_POINTER(geom);
}

/*
 * WKBFromLWGEOM(lwgeom) --> wkb
 * this will have no 'SRID=#;'
 */
PG_FUNCTION_INFO_V1(WKBFromLWGEOM);
Datum WKBFromLWGEOM(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        LWGEOM *lwgeom;
        uint8_t *wkb;
        size_t wkb_size;
        uint8_t variant = 0;
        bytea *result;
        text *type;
        /* If user specified endianness, respect it */
        if ( (PG_NARGS()>1) && (!PG_ARGISNULL(1)) )
        {
                type = PG_GETARG_TEXT_P(1);

                if  ( ! strncmp(VARDATA(type), "xdr", 3) ||
                      ! strncmp(VARDATA(type), "XDR", 3) )
                {
                        variant = variant | WKB_XDR;
                }
                else
                {
                        variant = variant | WKB_NDR;
                }
        }
        wkb_size= VARSIZE(geom) - VARHDRSZ;
        /* Create WKB hex string */
        lwgeom = lwgeom_from_gserialized(geom);

        wkb = lwgeom_to_wkb(lwgeom, variant | WKB_EXTENDED , &wkb_size);
        lwgeom_free(lwgeom);

        /* Prepare the PgSQL text return type */
        result = palloc(wkb_size + VARHDRSZ);
        memcpy(VARDATA(result), wkb, wkb_size);
        SET_VARSIZE(result, wkb_size+VARHDRSZ);

        /* Clean up and return */
        pfree(wkb);
        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_BYTEA_P(result);
}

PG_FUNCTION_INFO_V1(TWKBFromLWGEOM);
Datum TWKBFromLWGEOM(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom;
        LWGEOM *lwgeom;
        uint8_t *twkb;
        size_t twkb_size;
        uint8_t variant = 0;
        bytea *result;
        srs_precision sp;

        /*check for null input since we cannot have the sql-function as strict.
        That is because we use null as default for optional ID*/
        if ( PG_ARGISNULL(0) ) PG_RETURN_NULL();

        geom = PG_GETARG_GSERIALIZED_P(0);

        /* Read sensible precision defaults (about one meter) given the srs */
        sp = srid_axis_precision(fcinfo, gserialized_get_srid(geom), TWKB_DEFAULT_PRECISION);

        /* If user specified XY precision, use it */
        if ( PG_NARGS() > 1 && ! PG_ARGISNULL(1) )
                sp.precision_xy = PG_GETARG_INT32(1);

        /* If user specified Z precision, use it */
        if ( PG_NARGS() > 2 && ! PG_ARGISNULL(2) )
                sp.precision_z = PG_GETARG_INT32(2);

        /* If user specified M precision, use it */
        if ( PG_NARGS() > 3 && ! PG_ARGISNULL(3) )
                sp.precision_m = PG_GETARG_INT32(3);

        /* We don't permit ids for single geoemtries */
        variant = variant & ~TWKB_ID;

        /* If user wants registered twkb sizes */
        if ( PG_NARGS() > 4 && ! PG_ARGISNULL(4) && PG_GETARG_BOOL(4) )
                variant |= TWKB_SIZE;

        /* If user wants bounding boxes */
        if ( PG_NARGS() > 5 && ! PG_ARGISNULL(5) && PG_GETARG_BOOL(5) )
                variant |= TWKB_BBOX;

        /* Create TWKB binary string */
        lwgeom = lwgeom_from_gserialized(geom);
        twkb = lwgeom_to_twkb(lwgeom, variant, sp.precision_xy, sp.precision_z, sp.precision_m, &twkb_size);

        /* Prepare the PgSQL text return type */
        result = palloc(twkb_size + VARHDRSZ);
        memcpy(VARDATA(result), twkb, twkb_size);
        SET_VARSIZE(result, twkb_size + VARHDRSZ);

        PG_RETURN_BYTEA_P(result);
}


PG_FUNCTION_INFO_V1(TWKBFromLWGEOMArray);
Datum TWKBFromLWGEOMArray(PG_FUNCTION_ARGS)
{
        ArrayType *arr_geoms = NULL;
        ArrayType *arr_ids = NULL;
        int num_geoms, num_ids, i = 0;

        ArrayIterator iter_geoms, iter_ids;
        bool null_geom, null_id;
        Datum val_geom, val_id;

        int is_homogeneous = true;
        int subtype = 0;
        int has_z = 0;
        int has_m  = 0;
        LWCOLLECTION *col = NULL;
        int64_t *idlist = NULL;
        uint8_t variant = 0;

        srs_precision sp;
        uint8_t *twkb;
        size_t twkb_size;
        bytea *result;

        /* The first two arguments are required */
        if ( PG_NARGS() < 2 || PG_ARGISNULL(0) || PG_ARGISNULL(1) )
                PG_RETURN_NULL();

        arr_geoms = PG_GETARG_ARRAYTYPE_P(0);
        arr_ids = PG_GETARG_ARRAYTYPE_P(1);

        num_geoms = ArrayGetNItems(ARR_NDIM(arr_geoms), ARR_DIMS(arr_geoms));
        num_ids = ArrayGetNItems(ARR_NDIM(arr_ids), ARR_DIMS(arr_ids));

        if ( num_geoms != num_ids )
        {
                elog(ERROR, "size of geometry[] and integer[] arrays must match");
                PG_RETURN_NULL();
        }

        /* Loop through array and build a collection of geometry and */
        /* a simple array of ids. If either side is NULL, skip it */

#if POSTGIS_PGSQL_VERSION >= 95
        iter_geoms = array_create_iterator(arr_geoms, 0, NULL);
        iter_ids = array_create_iterator(arr_ids, 0, NULL);
#else
        iter_geoms = array_create_iterator(arr_geoms, 0);
        iter_ids = array_create_iterator(arr_ids, 0);
#endif

        while( array_iterate(iter_geoms, &val_geom, &null_geom) &&
               array_iterate(iter_ids, &val_id, &null_id) )
        {
                LWGEOM *geom;
                int32_t uid;

                if ( null_geom || null_id )
                {
                        elog(NOTICE, "ST_AsTWKB skipping NULL entry at position %d", i);
                        continue;
                }

                geom = lwgeom_from_gserialized((GSERIALIZED*)DatumGetPointer(val_geom));
                uid = DatumGetInt64(val_id);

                /* Construct collection/idlist first time through */
                if ( ! col )
                {
                        has_z = lwgeom_has_z(geom);
                        has_m = lwgeom_has_m(geom);
                        col = lwcollection_construct_empty(COLLECTIONTYPE, lwgeom_get_srid(geom), has_z, has_m);
                }
                if ( ! idlist )
                        idlist = palloc0(num_geoms * sizeof(int64_t));


                /*Check if there is differences in dimmenstionality*/
                if( lwgeom_has_z(geom)!=has_z || lwgeom_has_m(geom)!=has_m)
                {
                        elog(ERROR, "Geometries have differenct dimensionality");
                        PG_FREE_IF_COPY(arr_geoms, 0);
                        PG_FREE_IF_COPY(arr_ids, 1);
                        PG_RETURN_NULL();
                }
                /* Store the values */
                lwcollection_add_lwgeom(col, geom);
                idlist[i++] = uid;

                /* Grab the geometry type and note if all geometries share it */
                /* If so, we can make this a homogeneous collection and save some space */
                if ( lwgeom_get_type(geom) != subtype && subtype )
                {
                        is_homogeneous = false;
                }
                else
                {
                        subtype = lwgeom_get_type(geom);
                }

        }
        array_free_iterator(iter_geoms);
        array_free_iterator(iter_ids);

        if(i==0)
        {
                elog(NOTICE, "No valid geometry - id pairs found");
                PG_FREE_IF_COPY(arr_geoms, 0);
                PG_FREE_IF_COPY(arr_ids, 1);
                PG_RETURN_NULL();
        }
        if ( is_homogeneous )
        {
                col->type = lwtype_get_collectiontype(subtype);
        }

        /* Read sensible precision defaults (about one meter) given the srs */
        sp = srid_axis_precision(fcinfo, lwgeom_get_srid(lwcollection_as_lwgeom(col)), TWKB_DEFAULT_PRECISION);

        /* If user specified XY precision, use it */
        if ( PG_NARGS() > 2 && ! PG_ARGISNULL(2) )
                sp.precision_xy = PG_GETARG_INT32(2);

        /* If user specified Z precision, use it */
        if ( PG_NARGS() > 3 && ! PG_ARGISNULL(3) )
                sp.precision_z = PG_GETARG_INT32(3);

        /* If user specified M precision, use it */
        if ( PG_NARGS() > 4 && ! PG_ARGISNULL(4) )
                sp.precision_m = PG_GETARG_INT32(4);

        /* We are building an ID'ed output */
        variant = TWKB_ID;

        /* If user wants registered twkb sizes */
        if ( PG_NARGS() > 5 && ! PG_ARGISNULL(5) && PG_GETARG_BOOL(5) )
                variant |= TWKB_SIZE;

        /* If user wants bounding boxes */
        if ( PG_NARGS() > 6 && ! PG_ARGISNULL(6) && PG_GETARG_BOOL(6) )
                variant |= TWKB_BBOX;

        /* Write out the TWKB */
        twkb = lwgeom_to_twkb_with_idlist(lwcollection_as_lwgeom(col),
                                          idlist, variant,
                                          sp.precision_xy, sp.precision_z, sp.precision_m,
                                          &twkb_size);

        /* Convert to a bytea return type */
        result = palloc(twkb_size + VARHDRSZ);
        memcpy(VARDATA(result), twkb, twkb_size);
        SET_VARSIZE(result, twkb_size + VARHDRSZ);

        /* Clean up */
        pfree(twkb);
        pfree(idlist);
        lwcollection_free(col);
        PG_FREE_IF_COPY(arr_geoms, 0);
        PG_FREE_IF_COPY(arr_ids, 1);

        PG_RETURN_BYTEA_P(result);
}


/* puts a bbox inside the geometry */
PG_FUNCTION_INFO_V1(LWGEOM_addBBOX);
Datum LWGEOM_addBBOX(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *result;
        LWGEOM *lwgeom;

        lwgeom = lwgeom_from_gserialized(geom);
        lwgeom_add_bbox(lwgeom);
        result = geometry_serialize(lwgeom);

        PG_FREE_IF_COPY(geom, 0);
        PG_RETURN_POINTER(result);
}

/* removes a bbox from a geometry */
PG_FUNCTION_INFO_V1(LWGEOM_dropBBOX);
Datum LWGEOM_dropBBOX(PG_FUNCTION_ARGS)
{
        GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);

        /* No box? we're done already! */
        if ( ! gserialized_has_bbox(geom) )
                PG_RETURN_POINTER(geom);

        PG_RETURN_POINTER(gserialized_drop_gidx(geom));
}


/* for the wkt parser */
void elog_ERROR(const char* string)
{
        elog(ERROR, "%s", string);
}

/*
* This just does the same thing as the _in function,
* except it has to handle a 'text' input. First
* unwrap the text into a cstring, then call
* geometry_in
*/
PG_FUNCTION_INFO_V1(parse_WKT_lwgeom);
Datum parse_WKT_lwgeom(PG_FUNCTION_ARGS)
{
        text *wkt_text = PG_GETARG_TEXT_P(0);
        char *wkt;
        Datum result;

        /* Unwrap the PgSQL text type into a cstring */
        wkt = text2cstring(wkt_text);

        /* Now we call over to the geometry_in function */
        result = DirectFunctionCall1(LWGEOM_in, CStringGetDatum(wkt));

        /* Return null on null */
        if ( ! result )
                PG_RETURN_NULL();

        PG_RETURN_DATUM(result);
}


/*
 * This function must advance the StringInfo.cursor pointer
 * and leave it at the end of StringInfo.buf. If it fails
 * to do so the backend will raise an exception with message:
 * ERROR:  incorrect binary data format in bind parameter #
 *
 */
PG_FUNCTION_INFO_V1(LWGEOM_recv);
Datum LWGEOM_recv(PG_FUNCTION_ARGS)
{
        StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
        int32 geom_typmod = -1;
        GSERIALIZED *geom;
        LWGEOM *lwgeom;

        if ( (PG_NARGS()>2) && (!PG_ARGISNULL(2)) ) {
                geom_typmod = PG_GETARG_INT32(2);
        }

        lwgeom = lwgeom_from_wkb((uint8_t*)buf->data, buf->len, LW_PARSER_CHECK_ALL);

        if ( lwgeom_needs_bbox(lwgeom) )
                lwgeom_add_bbox(lwgeom);

        /* Set cursor to the end of buffer (so the backend is happy) */
        buf->cursor = buf->len;

        geom = geometry_serialize(lwgeom);
        lwgeom_free(lwgeom);

        if ( geom_typmod >= 0 )
        {
                geom = postgis_valid_typmod(geom, geom_typmod);
                POSTGIS_DEBUG(3, "typmod and geometry were consistent");
        }
        else
        {
                POSTGIS_DEBUG(3, "typmod was -1");
        }


        PG_RETURN_POINTER(geom);
}



PG_FUNCTION_INFO_V1(LWGEOM_send);
Datum LWGEOM_send(PG_FUNCTION_ARGS)
{
        POSTGIS_DEBUG(2, "LWGEOM_send called");

        PG_RETURN_POINTER(
          DatumGetPointer(
            DirectFunctionCall1(
              WKBFromLWGEOM,
              PG_GETARG_DATUM(0)
            )));
}

PG_FUNCTION_INFO_V1(LWGEOM_to_bytea);
Datum LWGEOM_to_bytea(PG_FUNCTION_ARGS)
{
        POSTGIS_DEBUG(2, "LWGEOM_to_bytea called");

        PG_RETURN_POINTER(
          DatumGetPointer(
            DirectFunctionCall1(
              WKBFromLWGEOM,
              PG_GETARG_DATUM(0)
            )));
}

PG_FUNCTION_INFO_V1(LWGEOM_from_bytea);
Datum LWGEOM_from_bytea(PG_FUNCTION_ARGS)
{
        GSERIALIZED *result;

        POSTGIS_DEBUG(2, "LWGEOM_from_bytea start");

        result = (GSERIALIZED *)DatumGetPointer(DirectFunctionCall1(
                                                  LWGEOMFromEWKB, PG_GETARG_DATUM(0)));

        PG_RETURN_POINTER(result);
}