/* * 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 java.util.Arrays; import java.util.List; import javax.annotation.Nonnull; 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.GenericUDTF; import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector; import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory; import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector; import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector; import org.apache.hadoop.hive.serde2.objectinspector.primitive.BooleanObjectInspector; /** * ConditionalEmit takes an array of booleans and strings, and emits records if the boolean is true. * * <p/> * This allows you to emit multiple rows on one pass of the data, rather than doing a union of * multiple views with different where clauses. * <p/> * * <pre> * select * conditional_emit( * array( maxwell_score > 80, abs( maxwell_score - other.maxwell_score ) < 5, city = "New York" ), * array( "CELEB", "PEER", "NEW_YORKER" ) * ) * from * table_to_scan_once * </pre> */ // @formatter:off @Description(name = "conditional_emit", value = "_FUNC_(array<boolean> conditions, array<primitive> features)" + " - Emit features of a row according to various conditions", extended = "WITH input as (\n" + " select array(true, false, true) as conditions, array(\"one\", \"two\", \"three\") as features\n" + " UNION ALL\n" + " select array(true, true, false), array(\"four\", \"five\", \"six\")\n" + ")\n" + "SELECT\n" + " conditional_emit(\n" + " conditions, features\n" + " )\n" + "FROM \n" + " input;\n" + " one\n" + " three\n" + " four\n" + " five") // @formatter:on @UDFType(deterministic = true, stateful = false) public final class ConditionalEmitUDTF extends GenericUDTF { private ListObjectInspector conditionsOI; private BooleanObjectInspector condElemOI; private ListObjectInspector featuresOI; private PrimitiveObjectInspector featureElemOI; private final Object[] forwardObj = new Object[1]; @Override public StructObjectInspector initialize(ObjectInspector[] argOIs) throws UDFArgumentException { if (argOIs.length != 2) { throw new UDFArgumentException( "conditional_emit takes 2 arguments: array<boolean>, array<primitive>"); } this.conditionsOI = HiveUtils.asListOI(argOIs[0]); this.condElemOI = HiveUtils.asBooleanOI(conditionsOI.getListElementObjectInspector()); this.featuresOI = HiveUtils.asListOI(argOIs[1]); this.featureElemOI = HiveUtils.asPrimitiveObjectInspector(featuresOI.getListElementObjectInspector()); List<String> fieldNames = Arrays.asList("feature"); List<ObjectInspector> fieldOIs = Arrays.<ObjectInspector>asList(featureElemOI); return ObjectInspectorFactory.getStandardStructObjectInspector(fieldNames, fieldOIs); } @Override public void process(@Nonnull Object[] args) throws HiveException { Object arg0 = args[0], arg1 = args[1]; if (arg0 == null || arg1 == null) { return; } final int conditionSize = conditionsOI.getListLength(arg0); final int featureSize = featuresOI.getListLength(arg1); if (conditionSize != featureSize) { throw new HiveException( "Arrays must be of same length in condition_emit(array<boolean> conditions, array<string> features).\n" + "#conditions=" + conditionSize + ", #features=" + featureSize); } for (int i = 0; i < conditionSize; i++) { Object condObj = conditionsOI.getListElement(arg0, i); if (condObj == null) { continue; } if (condElemOI.get(condObj) == false) { continue; } Object featureObj = featuresOI.getListElement(arg1, i); if (featureObj == null) { continue; } forwardObj[0] = featureObj; forward(forwardObj); } } @Override public void close() throws HiveException {} }