org.apache.hadoop.hive.ql.exec.ExprNodeColumnEvaluator Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hive.ql.exec;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.plan.ExprNodeColumnDesc;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.StructField;
import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.UnionObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.StandardUnionObjectInspector.StandardUnion;
/**
* This evaluator gets the column from the row object.
*/
public class ExprNodeColumnEvaluator extends ExprNodeEvaluator {
private transient boolean simpleCase;
private transient StructObjectInspector inspector;
private transient StructField field;
private transient StructObjectInspector[] inspectors;
private transient StructField[] fields;
private transient boolean[] unionField;
public ExprNodeColumnEvaluator(ExprNodeColumnDesc expr) {
super(expr);
}
@Override
public ObjectInspector initialize(ObjectInspector rowInspector) throws HiveException {
// We need to support field names like KEY.0, VALUE.1 between
// map-reduce boundary.
String[] names = expr.getColumn().split("\\.");
String[] unionfields = names[0].split("\\:");
if (names.length == 1 && unionfields.length == 1) {
simpleCase = true;
inspector = (StructObjectInspector) rowInspector;
field = inspector.getStructFieldRef(names[0]);
return outputOI = field.getFieldObjectInspector();
}
simpleCase = false;
inspectors = new StructObjectInspector[names.length];
fields = new StructField[names.length];
unionField = new boolean[names.length];
int unionIndex = -1;
for (int i = 0; i < names.length; i++) {
if (i == 0) {
inspectors[0] = (StructObjectInspector) rowInspector;
} else {
if (unionIndex == -1) {
inspectors[i] = (StructObjectInspector) fields[i - 1]
.getFieldObjectInspector();
} else {
inspectors[i] = (StructObjectInspector) (
(UnionObjectInspector)fields[i-1].getFieldObjectInspector()).
getObjectInspectors().get(unionIndex);
}
}
// to support names like _colx:1._coly
unionfields = names[i].split("\\:");
fields[i] = inspectors[i].getStructFieldRef(unionfields[0]);
if (unionfields.length > 1) {
unionIndex = Integer.parseInt(unionfields[1]);
unionField[i] = true;
} else {
unionIndex = -1;
unionField[i] = false;
}
}
return outputOI = fields[names.length - 1].getFieldObjectInspector();
}
@Override
protected Object _evaluate(Object row, int version) throws HiveException {
if (simpleCase) {
return inspector.getStructFieldData(row, field);
}
Object o = row;
for (int i = 0; i < fields.length; i++) {
o = inspectors[i].getStructFieldData(o, fields[i]);
if (unionField[i]) {
o = ((StandardUnion)o).getObject();
}
}
return o;
}
}