org.apache.hadoop.hive.ql.udf.generic.GenericUDFSize 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.udf.generic;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde.serdeConstants;
import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.MapObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.io.IntWritable;
/**
* GenericUDFSize.
*
*/
@Description(name = "size", value = "_FUNC_(a) - Returns the size of a")
public class GenericUDFSize extends GenericUDF {
private transient ObjectInspector returnOI;
private final transient IntWritable result = new IntWritable(-1);
@Override
public ObjectInspector initialize(ObjectInspector[] arguments)
throws UDFArgumentException {
if (arguments.length != 1) {
throw new UDFArgumentLengthException(
"The function SIZE only accepts 1 argument.");
}
Category category = arguments[0].getCategory();
String typeName = arguments[0].getTypeName();
if (category != Category.MAP && category != Category.LIST
&& !typeName.equals(serdeConstants.VOID_TYPE_NAME)) {
throw new UDFArgumentTypeException(0, "\""
+ Category.MAP.toString().toLowerCase() + "\" or \""
+ Category.LIST.toString().toLowerCase()
+ "\" is expected at function SIZE, " + "but \""
+ arguments[0].getTypeName() + "\" is found");
}
returnOI = arguments[0];
return PrimitiveObjectInspectorFactory.writableIntObjectInspector;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
Object data = arguments[0].get();
if (returnOI.getCategory() == Category.MAP) {
result.set(((MapObjectInspector) returnOI).getMapSize(data));
} else if (returnOI.getCategory() == Category.LIST) {
result.set(((ListObjectInspector) returnOI).getListLength(data));
} else if (returnOI.getTypeName().equals(serdeConstants.VOID_TYPE_NAME)) {
// null
result.set(-1);
}
return result;
}
@Override
public String getDisplayString(String[] children) {
assert (children.length == 1);
return getStandardDisplayString("size", children);
}
}