/**
* 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.UDFArgumentTypeException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.io.BooleanWritable;
/**
* GenericUDFArrayContains.
*
*/
@Description(name = "array_contains",
value="_FUNC_(array, value) - Returns TRUE if the array contains value.",
extended="Example:\n"
+ " > SELECT _FUNC_(array(1, 2, 3), 2) FROM src LIMIT 1;\n"
+ " true")
public class GenericUDFArrayContains extends GenericUDF {
private static final int ARRAY_IDX = 0;
private static final int VALUE_IDX = 1;
private static final int ARG_COUNT = 2; // Number of arguments to this UDF
private static final String FUNC_NAME = "ARRAY_CONTAINS"; // External Name
private transient ObjectInspector valueOI;
private transient ListObjectInspector arrayOI;
private transient ObjectInspector arrayElementOI;
private BooleanWritable result;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments)
throws UDFArgumentException {
// Check if two arguments were passed
if (arguments.length != ARG_COUNT) {
throw new UDFArgumentException(
"The function " + FUNC_NAME + " accepts "
+ ARG_COUNT + " arguments.");
}
// Check if ARRAY_IDX argument is of category LIST
if (!arguments[ARRAY_IDX].getCategory().equals(Category.LIST)) {
throw new UDFArgumentTypeException(ARRAY_IDX,
"\"" + org.apache.hadoop.hive.serde.serdeConstants.LIST_TYPE_NAME + "\" "
+ "expected at function ARRAY_CONTAINS, but "
+ "\"" + arguments[ARRAY_IDX].getTypeName() + "\" "
+ "is found");
}
arrayOI = (ListObjectInspector) arguments[ARRAY_IDX];
arrayElementOI = arrayOI.getListElementObjectInspector();
valueOI = arguments[VALUE_IDX];
// Check if list element and value are of same type
if (!ObjectInspectorUtils.compareTypes(arrayElementOI, valueOI)) {
throw new UDFArgumentTypeException(VALUE_IDX,
"\"" + arrayElementOI.getTypeName() + "\""
+ " expected at function ARRAY_CONTAINS, but "
+ "\"" + valueOI.getTypeName() + "\""
+ " is found");
}
// Check if the comparison is supported for this type
if (!ObjectInspectorUtils.compareSupported(valueOI)) {
throw new UDFArgumentException("The function " + FUNC_NAME
+ " does not support comparison for "
+ "\"" + valueOI.getTypeName() + "\""
+ " types");
}
result = new BooleanWritable(false);
return PrimitiveObjectInspectorFactory.writableBooleanObjectInspector;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
result.set(false);
Object array = arguments[ARRAY_IDX].get();
Object value = arguments[VALUE_IDX].get();
int arrayLength = arrayOI.getListLength(array);
// Check if array is null or empty or value is null
if (value == null || arrayLength <= 0) {
return result;
}
// Compare the value to each element of array until a match is found
for (int i=0; i<arrayLength; ++i) {
Object listElement = arrayOI.getListElement(array, i);
if (listElement != null) {
if (ObjectInspectorUtils.compare(value, valueOI,
listElement, arrayElementOI) == 0) {
result.set(true);
break;
}
}
}
return result;
}
@Override
public String getDisplayString(String[] children) {
assert (children.length == ARG_COUNT);
return "array_contains(" + children[ARRAY_IDX] + ", "
+ children[VALUE_IDX] + ")";
}
}