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.hadoop.io.IntWritable;
import com.esri.core.geometry.ogc.OGCGeometry;
import com.esri.core.geometry.ogc.OGCMultiPoint;
import com.esri.core.geometry.ogc.OGCMultiLineString;
import com.esri.core.geometry.ogc.OGCMultiPolygon;
@Description(
name = "ST_GeometryN",
value = "_FUNC_(ST_GeometryCollection, n) - return the nth ST_Geometry in the collection (1-based index)",
extended = "Example:\n"
+ " SELECT _FUNC_(ST_GeomFromText('multipoint ((10 40), (40 30), (20 20), (30 10))'), 3) FROM src LIMIT 1; -- ST_Point(20 20)\n"
+ " SELECT _FUNC_(ST_GeomFromText('multilinestring ((2 4, 10 10), (20 20, 7 8))'), 2) FROM src LIMIT 1; -- ST_Linestring(20 20, 7 8)\n"
)
public class ST_GeometryN extends ST_GeometryAccessor {
static final Log LOG = LogFactory.getLog(ST_GeometryN.class.getName());
public BytesWritable evaluate(BytesWritable geomref, IntWritable index) {
if (geomref == null || geomref.getLength() == 0 || index == null) {
LogUtils.Log_ArgumentsNull(LOG);
return null;
}
OGCGeometry ogcGeometry = GeometryUtils.geometryFromEsriShape(geomref);
if (ogcGeometry == null){
LogUtils.Log_ArgumentsNull(LOG);
return null;
}
int idx = index.get() - 1; // 1-based UI, 0-based engine
try {
GeometryUtils.OGCType ogcType = GeometryUtils.getType(geomref);
OGCGeometry ogcGeom = null;
switch(ogcType) {
case ST_POINT:
LogUtils.Log_InvalidType(LOG, GeometryUtils.OGCType.ST_MULTIPOINT, ogcType);
return null;
case ST_LINESTRING:
LogUtils.Log_InvalidType(LOG, GeometryUtils.OGCType.ST_MULTILINESTRING, ogcType);
return null;
case ST_POLYGON:
LogUtils.Log_InvalidType(LOG, GeometryUtils.OGCType.ST_MULTIPOLYGON, ogcType);
return null;
case ST_MULTIPOINT:
ogcGeom = ((OGCMultiPoint)ogcGeometry).geometryN(idx);
break;
case ST_MULTILINESTRING:
ogcGeom = ((OGCMultiLineString)ogcGeometry).geometryN(idx);
break;
case ST_MULTIPOLYGON:
ogcGeom = ((OGCMultiPolygon)ogcGeometry).geometryN(idx);
break;
}
return GeometryUtils.geometryToEsriShapeBytesWritable(ogcGeom);
} catch (Exception e) {
LogUtils.Log_InternalError(LOG, "ST_GeometryN: " + e);
return null;
}
}
}