package com.esri.hadoop.hive;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hive.pdk.HivePdkUnitTest;
import org.apache.hive.pdk.HivePdkUnitTests;
import com.esri.core.geometry.Geometry;
import com.esri.core.geometry.GeometryEngine;
import com.esri.core.geometry.SpatialReference;
import com.esri.hadoop.hive.GeometryUtils.OGCType;
import com.esri.core.geometry.ogc.OGCGeometry;
@Description(
name = "ST_Union",
value = "_FUNC_(ST_Geometry, ST_Geometry, ...) - returns an ST_Geometry as the union of the supplied ST_Geometries",
extended = "Example: SELECT ST_AsText(ST_Union(ST_Polygon(1, 1, 1, 4, 4, 4, 4, 1), ST_Polygon(4, 1, 4, 4, 4, 8, 8, 1))) FROM onerow;\n" +
"MULTIPOLYGON (((4 1, 8 1, 4 8, 4 4, 1 4, 1 1, 4 1)))")
@HivePdkUnitTests(
cases = {
@HivePdkUnitTest(
query = "SELECT ST_AsText(ST_Union(ST_Point(1.1, 2.2), ST_Point(3.3, 4.4))) FROM onerow",
result = "MULTIPOINT (1.1 2.2, 3.3 4.4)"
),
@HivePdkUnitTest(
query = "SELECT ST_AsText(ST_Union(ST_Polygon(1, 1, 1, 4, 4, 4, 4, 1), ST_Polygon(4,1, 4,8, 8,1))) FROM onerow",
result = "MULTIPOLYGON (((4 1, 8 1, 4 8, 4 4, 1 4, 1 1, 4 1)))"
),
@HivePdkUnitTest(
query = "SELECT ST_AsText(ST_Union(ST_Point(1.1, 2.2), ST_Point(3.3, 4.4), ST_Point(5.5, 6.6), ST_Point(1.1, 2.2))) FROM onerow",
result = "MULTIPOINT (1.1 2.2, 3.3 4.4, 5.5 6.6)"
)
}
)
public class ST_Union extends ST_GeometryProcessing
{
static final Log LOG = LogFactory.getLog(ST_Union.class.getName());
public BytesWritable evaluate (BytesWritable ... geomrefs){
// validate arguments
if (geomrefs == null || geomrefs.length < 2){
LogUtils.Log_VariableArgumentLength(LOG);
}
int firstWKID = 0;
SpatialReference spatialRef = null;
// validate spatial references and geometries first
for (int i=0;i<geomrefs.length; i++){
BytesWritable geomref = geomrefs[i];
if (geomref == null || geomref.getLength() == 0){
LogUtils.Log_ArgumentsNull(LOG);
return null;
}
if (i==0){
firstWKID = GeometryUtils.getWKID(geomref);
if (firstWKID != GeometryUtils.WKID_UNKNOWN) {
spatialRef = SpatialReference.create(firstWKID);
}
} else if (firstWKID != GeometryUtils.getWKID(geomref)){
LogUtils.Log_SRIDMismatch(LOG, geomrefs[0], geomref);
return null;
}
}
// now build geometry array to pass to GeometryEngine.union
Geometry [] geomsToUnion = new Geometry[geomrefs.length];
for (int i=0;i<geomrefs.length;i++){
//HiveGeometry hiveGeometry = GeometryUtils.geometryFromEsriShape(geomrefs[i]);
OGCGeometry ogcGeometry = GeometryUtils.geometryFromEsriShape(geomrefs[i]);
// if (i==0){ // get from ogcGeometry rather than re-create above?
// spatialRef = hiveGeometry.spatialReference;
// }
if (ogcGeometry == null){
LogUtils.Log_ArgumentsNull(LOG);
return null;
}
geomsToUnion[i] = ogcGeometry.getEsriGeometry();
}
try {
Geometry unioned = GeometryEngine.union(geomsToUnion, spatialRef);
// we have to infer the type of the differenced geometry because we don't know
// if it's going to end up as a single or multi-part geometry
OGCType inferredType = GeometryUtils.getInferredOGCType(unioned);
return GeometryUtils.geometryToEsriShapeBytesWritable(unioned, firstWKID, inferredType);
} catch (Exception e){
LogUtils.Log_ExceptionThrown(LOG, "GeometryEngine.union", e);
return null;
}
}
}