lwgeom_from_wkb_state()

LWGEOM * lwgeom_from_wkb_state

(

wkb_parse_state *

s

)

Internal function declarations.

GEOMETRY Generic handling for WKB geometries.

The front of every WKB geometry (including those embedded in collections) is an endian byte, a type number and an optional srid number. We handle all those here, then pass to the appropriate handler for the specific type.

Definition at line 734 of file lwin_wkb.c.

{
        char wkb_little_endian;
        uint32_t wkb_type;
 
        LWDEBUG(4,"Entered function");
 
        /* Fail when handed incorrect starting byte */
        wkb_little_endian = byte_from_wkb_state(s);
        if (s->error)
                return NULL;
        if( wkb_little_endian != 1 && wkb_little_endian != 0 )
        {
                LWDEBUG(4,"Leaving due to bad first byte!");
                lwerror("Invalid endian flag value encountered.");
                return NULL;
        }
 
        /* Check the endianness of our input  */
        s->swap_bytes = LW_FALSE;
 
        /* Machine arch is big endian, request is for little */
        if (IS_BIG_ENDIAN && wkb_little_endian)
                s->swap_bytes = LW_TRUE;
        /* Machine arch is little endian, request is for big */
        else if ((!IS_BIG_ENDIAN) && (!wkb_little_endian))
                s->swap_bytes = LW_TRUE;
 
        /* Read the type number */
        wkb_type = integer_from_wkb_state(s);
        if (s->error)
                return NULL;
        LWDEBUGF(4,"Got WKB type number: 0x%X", wkb_type);
        lwtype_from_wkb_state(s, wkb_type);
 
        /* Read the SRID, if necessary */
        if( s->has_srid )
        {
                s->srid = clamp_srid(integer_from_wkb_state(s));
                if (s->error)
                        return NULL;
                /* TODO: warn on explicit UNKNOWN srid ? */
                LWDEBUGF(4,"Got SRID: %u", s->srid);
        }
 
        /* Do the right thing */
        switch( s->lwtype )
        {
                case POINTTYPE:
                        return (LWGEOM*)lwpoint_from_wkb_state(s);
                        break;
                case LINETYPE:
                        return (LWGEOM*)lwline_from_wkb_state(s);
                        break;
                case CIRCSTRINGTYPE:
                        return (LWGEOM*)lwcircstring_from_wkb_state(s);
                        break;
                case POLYGONTYPE:
                        return (LWGEOM*)lwpoly_from_wkb_state(s);
                        break;
                case TRIANGLETYPE:
                        return (LWGEOM*)lwtriangle_from_wkb_state(s);
                        break;
                case CURVEPOLYTYPE:
                        return (LWGEOM*)lwcurvepoly_from_wkb_state(s);
                        break;
                case MULTIPOINTTYPE:
                case MULTILINETYPE:
                case MULTIPOLYGONTYPE:
                case COMPOUNDTYPE:
                case MULTICURVETYPE:
                case MULTISURFACETYPE:
                case POLYHEDRALSURFACETYPE:
                case TINTYPE:
                case COLLECTIONTYPE:
                        return (LWGEOM*)lwcollection_from_wkb_state(s);
                        break;
 
                /* Unknown type! */
                default:
                        lwerror("%s: Unsupported geometry type: %s", __func__, lwtype_name(s->lwtype));
        }
 
        /* Return value to keep compiler happy. */
        return NULL;
 
}

References byte_from_wkb_state(), CIRCSTRINGTYPE, clamp_srid(), COLLECTIONTYPE, COMPOUNDTYPE, CURVEPOLYTYPE, integer_from_wkb_state(), IS_BIG_ENDIAN, LINETYPE, LW_FALSE, LW_TRUE, lwcircstring_from_wkb_state(), lwcollection_from_wkb_state(), lwcurvepoly_from_wkb_state(), LWDEBUG, LWDEBUGF, lwerror(), lwline_from_wkb_state(), lwpoint_from_wkb_state(), lwpoly_from_wkb_state(), lwtriangle_from_wkb_state(), lwtype_from_wkb_state(), lwtype_name(), MULTICURVETYPE, MULTILINETYPE, MULTIPOINTTYPE, MULTIPOLYGONTYPE, MULTISURFACETYPE, POINTTYPE, POLYGONTYPE, POLYHEDRALSURFACETYPE, s, TINTYPE, and TRIANGLETYPE.

Referenced by lwcollection_from_wkb_state(), lwcurvepoly_from_wkb_state(), and lwgeom_from_wkb().

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