/tags/release-0.1-rc2/hive/external/ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDFArrayContains.java
Java | 137 lines | 87 code | 23 blank | 27 comment | 14 complexity | 9179f846b995eadad67d520798824a64 MD5 | raw file
Possible License(s): Apache-2.0, BSD-3-Clause, JSON, CPL-1.0
- /**
- * 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.ObjectInspectorUtils;
- import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category;
- 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 ObjectInspector valueOI;
- private ListObjectInspector arrayOI;
- private 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.Constants.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] + ")";
- }
- }