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.ogc.OGCGeometry;
import com.esri.core.geometry.ogc.OGCMultiLineString;
@Description(
name = "ST_Boundary",
value = "_FUNC_(ST_Geometry) - boundary of the input ST_Geometry",
extended = "Example:\n"
+ " SELECT _FUNC_(ST_LineString(0,1, 1,0))) FROM src LIMIT 1; -- MULTIPOINT((1 0),(0 1))\n"
+ " SELECT _FUNC_(ST_Polygon(1,1, 4,1, 1,4)) FROM src LIMIT 1; -- LINESTRING(1 1, 4 1, 1 4, 1 1)\n"
)
@HivePdkUnitTests(
cases = {
@HivePdkUnitTest(
query = "select ST_GeometryType(ST_Boundary(ST_Linestring('linestring (10 10, 20 20)'))) from onerow",
result = "ST_MULTIPOINT"
),
@HivePdkUnitTest(
query = "select ST_Equals(ST_Boundary(ST_Linestring('linestring (10 10, 20 20)')), ST_GeomFromText('multipoint ((10 10), (20 20))')) from onerow",
result = "true"
)
}
)
// The boundary of a point (or multipoint) is the empty set OGC 4.18, 6.1.5
// The boundary of a closed curve is empty; non-closed curve, its 2 end points OGC 6.1.6.1
// The boundary of a surface is the set of closed curves that form its limits OGC 4.21
public class ST_Boundary extends ST_GeometryProcessing {
static final Log LOG = LogFactory.getLog(ST_Boundary.class.getName());
public BytesWritable evaluate(BytesWritable geomref) {
if (geomref == null || geomref.getLength() == 0) {
LogUtils.Log_ArgumentsNull(LOG);
return null;
}
OGCGeometry ogcGeometry = GeometryUtils.geometryFromEsriShape(geomref);
if (ogcGeometry == null){
LogUtils.Log_ArgumentsNull(LOG);
return null;
}
try {
OGCGeometry boundGeom = ogcGeometry.boundary();
if (boundGeom.geometryType().equals("MultiLineString") && ((OGCMultiLineString)boundGeom).numGeometries() == 1)
boundGeom = ((OGCMultiLineString)boundGeom).geometryN(0); // match ST_Boundary/SQL-RDBMS
return GeometryUtils.geometryToEsriShapeBytesWritable(boundGeom);
} catch (Exception e) {
LogUtils.Log_InternalError(LOG, "ST_Boundary: " + e);
return null;
}
}
}