/* * 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 hivemall.tools.array; import hivemall.utils.hadoop.HiveUtils; import hivemall.utils.lang.StringUtils; import java.util.ArrayList; import java.util.List; import org.apache.hadoop.hive.ql.exec.Description; import org.apache.hadoop.hive.ql.exec.UDFArgumentException; import org.apache.hadoop.hive.ql.metadata.HiveException; import org.apache.hadoop.hive.ql.udf.UDFType; import org.apache.hadoop.hive.ql.udf.generic.GenericUDF; 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.ObjectInspectorFactory; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils.ObjectInspectorCopyOption; @Description(name = "array_flatten", value = "_FUNC_(array<array<ANY>>) - Returns an array with the elements flattened.", extended = "SELECT array_flatten(array(array(1,2,3),array(4,5),array(6,7,8)));\n" + " [1,2,3,4,5,6,7,8]") @UDFType(deterministic = true, stateful = false) public final class ArrayFlattenUDF extends GenericUDF { private ListObjectInspector listOI; private final List<Object> result = new ArrayList<>(); @Override public ObjectInspector initialize(ObjectInspector[] argOIs) throws UDFArgumentException { if (argOIs.length != 1) { throw new UDFArgumentException( "array_flatten expects exactly one argument: " + argOIs.length); } this.listOI = HiveUtils.asListOI(argOIs[0]); ObjectInspector listElemOI = listOI.getListElementObjectInspector(); if (listElemOI.getCategory() != Category.LIST) { throw new UDFArgumentException( "array_flatten takes array of array for the argument: " + listOI.toString()); } ListObjectInspector nestedListOI = HiveUtils.asListOI(listElemOI); ObjectInspector elemOI = nestedListOI.getListElementObjectInspector(); return ObjectInspectorFactory.getStandardListObjectInspector( ObjectInspectorUtils.getStandardObjectInspector(elemOI, ObjectInspectorCopyOption.WRITABLE)); } @Override public List<Object> evaluate(DeferredObject[] args) throws HiveException { result.clear(); Object arg0 = args[0].get(); if (arg0 == null) { return null; } final int listLength = listOI.getListLength(arg0); for (int i = 0; i < listLength; i++) { final Object subarray = listOI.getListElement(arg0, i); if (subarray == null) { continue; } final ListObjectInspector subarrayOI = HiveUtils.asListOI(listOI.getListElementObjectInspector()); final ObjectInspector elemOI = subarrayOI.getListElementObjectInspector(); final int subarrayLength = subarrayOI.getListLength(subarray); for (int j = 0; j < subarrayLength; j++) { Object rawElem = subarrayOI.getListElement(subarray, j); if (rawElem == null) { continue; } Object elem = ObjectInspectorUtils.copyToStandardObject(rawElem, elemOI, ObjectInspectorCopyOption.WRITABLE); result.add(elem); } } return result; } @Override public String getDisplayString(String[] args) { return "array_flatten(" + StringUtils.join(args, ',') + ")"; } }