PostGIS  3.0.6dev-r@@SVN_REVISION@@

◆ 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 726 of file lwin_wkb.c.

727 {
728  char wkb_little_endian;
729  uint32_t wkb_type;
730 
731  LWDEBUG(4,"Entered function");
732 
733  /* Fail when handed incorrect starting byte */
734  wkb_little_endian = byte_from_wkb_state(s);
735  if (s->error)
736  return NULL;
737  if( wkb_little_endian != 1 && wkb_little_endian != 0 )
738  {
739  LWDEBUG(4,"Leaving due to bad first byte!");
740  lwerror("Invalid endian flag value encountered.");
741  return NULL;
742  }
743 
744  /* Check the endianness of our input */
745  s->swap_bytes = LW_FALSE;
746 
747  /* Machine arch is big endian, request is for little */
748  if (IS_BIG_ENDIAN && wkb_little_endian)
749  s->swap_bytes = LW_TRUE;
750  /* Machine arch is little endian, request is for big */
751  else if ((!IS_BIG_ENDIAN) && (!wkb_little_endian))
752  s->swap_bytes = LW_TRUE;
753 
754  /* Read the type number */
755  wkb_type = integer_from_wkb_state(s);
756  if (s->error)
757  return NULL;
758  LWDEBUGF(4,"Got WKB type number: 0x%X", wkb_type);
759  lwtype_from_wkb_state(s, wkb_type);
760 
761  /* Read the SRID, if necessary */
762  if( s->has_srid )
763  {
765  if (s->error)
766  return NULL;
767  /* TODO: warn on explicit UNKNOWN srid ? */
768  LWDEBUGF(4,"Got SRID: %u", s->srid);
769  }
770 
771  /* Do the right thing */
772  switch( s->lwtype )
773  {
774  case POINTTYPE:
775  return (LWGEOM*)lwpoint_from_wkb_state(s);
776  break;
777  case LINETYPE:
778  return (LWGEOM*)lwline_from_wkb_state(s);
779  break;
780  case CIRCSTRINGTYPE:
782  break;
783  case POLYGONTYPE:
784  return (LWGEOM*)lwpoly_from_wkb_state(s);
785  break;
786  case TRIANGLETYPE:
788  break;
789  case CURVEPOLYTYPE:
791  break;
792  case MULTIPOINTTYPE:
793  case MULTILINETYPE:
794  case MULTIPOLYGONTYPE:
795  case COMPOUNDTYPE:
796  case MULTICURVETYPE:
797  case MULTISURFACETYPE:
799  case TINTYPE:
800  case COLLECTIONTYPE:
802  break;
803 
804  /* Unknown type! */
805  default:
806  lwerror("%s: Unsupported geometry type: %s", __func__, lwtype_name(s->lwtype));
807  }
808 
809  /* Return value to keep compiler happy. */
810  return NULL;
811 
812 }
char * s
Definition: cu_in_wkt.c:23
#define LW_FALSE
Definition: liblwgeom.h:108
#define COLLECTIONTYPE
Definition: liblwgeom.h:122
#define COMPOUNDTYPE
Definition: liblwgeom.h:124
#define CURVEPOLYTYPE
Definition: liblwgeom.h:125
#define MULTILINETYPE
Definition: liblwgeom.h:120
#define MULTISURFACETYPE
Definition: liblwgeom.h:127
#define LINETYPE
Definition: liblwgeom.h:117
#define MULTIPOINTTYPE
Definition: liblwgeom.h:119
#define POINTTYPE
LWTYPE numbers, used internally by PostGIS.
Definition: liblwgeom.h:116
#define TINTYPE
Definition: liblwgeom.h:130
#define MULTIPOLYGONTYPE
Definition: liblwgeom.h:121
#define POLYGONTYPE
Definition: liblwgeom.h:118
#define POLYHEDRALSURFACETYPE
Definition: liblwgeom.h:128
#define CIRCSTRINGTYPE
Definition: liblwgeom.h:123
const char * lwtype_name(uint8_t type)
Return the type name string associated with a type number (e.g.
Definition: lwutil.c:216
#define MULTICURVETYPE
Definition: liblwgeom.h:126
#define TRIANGLETYPE
Definition: liblwgeom.h:129
#define LW_TRUE
Return types for functions with status returns.
Definition: liblwgeom.h:107
int32_t clamp_srid(int32_t srid)
Return a valid SRID from an arbitrary integer Raises a notice if what comes out is different from wha...
Definition: lwutil.c:333
#define IS_BIG_ENDIAN
#define LWDEBUG(level, msg)
Definition: lwgeom_log.h:83
#define LWDEBUGF(level, msg,...)
Definition: lwgeom_log.h:88
void lwerror(const char *fmt,...)
Write a notice out to the error handler.
Definition: lwutil.c:190
static uint32_t integer_from_wkb_state(wkb_parse_state *s)
Int32 Read 4-byte integer and advance the parse state forward.
Definition: lwin_wkb.c:278
static LWCURVEPOLY * lwcurvepoly_from_wkb_state(wkb_parse_state *s)
CURVEPOLYTYPE.
Definition: lwin_wkb.c:639
static LWPOLY * lwpoly_from_wkb_state(wkb_parse_state *s)
POLYGON Read a WKB polygon, starting just after the endian byte, type number and optional srid number...
Definition: lwin_wkb.c:529
static LWPOINT * lwpoint_from_wkb_state(wkb_parse_state *s)
POINT Read a WKB point, starting just after the endian byte, type number and optional srid number.
Definition: lwin_wkb.c:404
static LWLINE * lwline_from_wkb_state(wkb_parse_state *s)
LINESTRING Read a WKB linestring, starting just after the endian byte, type number and optional srid ...
Definition: lwin_wkb.c:462
static LWCOLLECTION * lwcollection_from_wkb_state(wkb_parse_state *s)
POLYHEDRALSURFACETYPE.
Definition: lwin_wkb.c:676
static char byte_from_wkb_state(wkb_parse_state *s)
Byte Read a byte and advance the parse state forward.
Definition: lwin_wkb.c:257
static LWCIRCSTRING * lwcircstring_from_wkb_state(wkb_parse_state *s)
CIRCULARSTRING Read a WKB circularstring, starting just after the endian byte, type number and option...
Definition: lwin_wkb.c:493
static void lwtype_from_wkb_state(wkb_parse_state *s, uint32_t wkb_type)
Take in an unknown kind of wkb type number and ensure it comes out as an extended WKB type number (wi...
Definition: lwin_wkb.c:145
static LWTRIANGLE * lwtriangle_from_wkb_state(wkb_parse_state *s)
TRIANGLE Read a WKB triangle, starting just after the endian byte, type number and optional srid numb...
Definition: lwin_wkb.c:591

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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