PostGIS  2.2.8dev-r@@SVN_REVISION@@

◆ cluster_within_distance_garray()

Datum cluster_within_distance_garray ( PG_FUNCTION_ARGS  )

Definition at line 3496 of file postgis/lwgeom_geos.c.

References ARRAY2LWGEOM(), array_nelems_not_null(), cluster_within_distance(), gserialized_from_lwgeom(), linemerge(), LW_SUCCESS, lwgeom_free(), lwgeom_geos_error(), PG_FUNCTION_INFO_V1(), and SRID_UNKNOWN.

Referenced by clusterintersecting_garray(), and pgis_geometry_clusterwithin_finalfn().

3497 {
3498  Datum* result_array_data;
3499  ArrayType *array, *result;
3500  int is3d = 0;
3501  uint32 nelems, nclusters, i;
3502  LWGEOM** lw_inputs;
3503  LWGEOM** lw_results;
3504  double tolerance;
3505  int srid=SRID_UNKNOWN;
3506 
3507  /* Parameters used to construct a result array */
3508  int16 elmlen;
3509  bool elmbyval;
3510  char elmalign;
3511 
3512  /* Null array, null geometry (should be empty?) */
3513  if (PG_ARGISNULL(0))
3514  PG_RETURN_NULL();
3515 
3516  array = PG_GETARG_ARRAYTYPE_P(0);
3517  tolerance = PG_GETARG_FLOAT8(1);
3518  nelems = array_nelems_not_null(array);
3519 
3520  POSTGIS_DEBUGF(3, "cluster_within_distance_garray: number of non-null elements: %d", nelems);
3521 
3522  if ( nelems == 0 ) PG_RETURN_NULL();
3523 
3524  /* TODO short-circuit for one element? */
3525 
3526  /* Ok, we really need geos now ;) */
3527  initGEOS(lwpgnotice, lwgeom_geos_error);
3528 
3529  lw_inputs = ARRAY2LWGEOM(array, nelems, &is3d, &srid);
3530  if (!lw_inputs)
3531  {
3532  PG_RETURN_NULL();
3533  }
3534 
3535  if (cluster_within_distance(lw_inputs, nelems, tolerance, &lw_results, &nclusters) != LW_SUCCESS)
3536  {
3537  elog(ERROR, "cluster_within: Error performing clustering");
3538  PG_RETURN_NULL();
3539  }
3540  pfree(lw_inputs); /* don't need to destroy items because GeometryCollections have taken ownership */
3541 
3542  if (!lw_results) PG_RETURN_NULL();
3543 
3544  result_array_data = palloc(nclusters * sizeof(Datum));
3545  for (i=0; i<nclusters; ++i)
3546  {
3547  result_array_data[i] = PointerGetDatum(gserialized_from_lwgeom(lw_results[i], 0, NULL));
3548  lwgeom_free(lw_results[i]);
3549  }
3550  pfree(lw_results);
3551 
3552  get_typlenbyvalalign(array->elemtype, &elmlen, &elmbyval, &elmalign);
3553  result = (ArrayType*) construct_array(result_array_data, nclusters, array->elemtype, elmlen, elmbyval, elmalign);
3554 
3555  if (!result)
3556  {
3557  elog(ERROR, "clusterwithin: Error constructing return-array");
3558  PG_RETURN_NULL();
3559  }
3560 
3561  PG_RETURN_POINTER(result);
3562 }
uint32_t array_nelems_not_null(ArrayType *array)
void lwgeom_free(LWGEOM *geom)
Definition: lwgeom.c:1050
#define LW_SUCCESS
Definition: liblwgeom.h:65
int cluster_within_distance(LWGEOM **geoms, uint32_t num_geoms, double tolerance, LWGEOM ***clusterGeoms, uint32_t *num_clusters)
Takes an array of LWGEOM* and constructs an array of LWGEOM*, where each element in the constructed a...
LWGEOM ** ARRAY2LWGEOM(ArrayType *array, uint32_t nelems, int *is3d, int *srid)
void lwgeom_geos_error(const char *fmt,...)
#define SRID_UNKNOWN
Unknown SRID value.
Definition: liblwgeom.h:172
GSERIALIZED * gserialized_from_lwgeom(LWGEOM *geom, int is_geodetic, size_t *size)
Allocate a new GSERIALIZED from an LWGEOM.
Definition: g_serialized.c:906
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