/*
* SwapBytes?
*/
static inline int wkb_swap_bytes(uint8_t variant)
{
/* If requested variant matches machine arch, we don't have to swap! */
if ( ((variant & WKB_NDR) && (getMachineEndian() == NDR)) ||
((! (variant & WKB_NDR)) && (getMachineEndian() == XDR)) )
{
return LW_FALSE;
}
return LW_TRUE;
}
/**
* 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.
*/
LWGEOM* lwgeom_from_wkb_state(wkb_parse_state *s)
{
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( 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;
if( getMachineEndian() == NDR ) /* Machine arch is little */
{
if ( ! wkb_little_endian ) /* Data is big! */
s->swap_bytes = LW_TRUE;
}
else /* Machine arch is big */
{
if ( wkb_little_endian ) /* Data is little! */
s->swap_bytes = LW_TRUE;
}
/* Read the type number */
wkb_type = integer_from_wkb_state(s);
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));
/* 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("Unsupported geometry type: %s [%d]", lwtype_name(s->lwtype), s->lwtype);
}
/* Return value to keep compiler happy. */
return NULL;
}
