| /* |
| * Copyright 2016, Yahoo! Inc. |
| * Licensed under the terms of the Apache License 2.0. See LICENSE file at the project root for terms. |
| */ |
| |
| package com.yahoo.sketches.hive.quantiles; |
| |
| import java.util.Comparator; |
| |
| import org.apache.hadoop.hive.common.type.HiveChar; |
| import org.apache.hadoop.hive.common.type.HiveVarchar; |
| import org.apache.hadoop.hive.ql.exec.Description; |
| import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException; |
| import org.apache.hadoop.hive.ql.metadata.HiveException; |
| import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator; |
| import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector; |
| |
| import com.yahoo.sketches.ArrayOfStringsSerDe; |
| |
| @Description(name = "DataToSketch", value = "_FUNC_(value, k) - " |
| + "Returns an ItemsSketch<String> in a serialized form as a binary blob." |
| + " Values must be of string type." |
| + " Parameter k controls the accuracy and the size of the sketch." |
| + " If k is ommitted, the default is used.") |
| @SuppressWarnings("javadoc") |
| public class DataToStringsSketchUDAF extends DataToItemsSketchUDAF<String> { |
| |
| @Override |
| public GenericUDAFEvaluator createEvaluator() { |
| return new DataToStringsSketchEvaluator(); |
| } |
| |
| static class DataToStringsSketchEvaluator extends DataToSketchEvaluator<String> { |
| |
| DataToStringsSketchEvaluator() { |
| super(Comparator.naturalOrder(), new ArrayOfStringsSerDe()); |
| } |
| |
| @Override |
| public String extractValue(final Object data, final ObjectInspector objectInspector) |
| throws HiveException { |
| final Object value = inputObjectInspector.getPrimitiveJavaObject(data); |
| if (value instanceof String) { |
| return (String) value; |
| } else if (value instanceof HiveChar) { |
| return ((HiveChar) value).getValue(); |
| } else if (value instanceof HiveVarchar) { |
| return ((HiveVarchar) value).getValue(); |
| } else { |
| throw new UDFArgumentTypeException(0, "unsupported type " + value.getClass().getName()); |
| } |
| } |
| |
| } |
| |
| } |