| /* |
| * 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.datasketches.hive.cpc; |
| |
| import static org.apache.datasketches.Util.DEFAULT_UPDATE_SEED; |
| |
| import org.apache.datasketches.cpc.CpcSketch; |
| import org.apache.datasketches.memory.Memory; |
| import org.apache.hadoop.hive.ql.exec.Description; |
| import org.apache.hadoop.hive.ql.exec.UDF; |
| import org.apache.hadoop.io.BytesWritable; |
| |
| @Description( |
| name = "SketchToString", |
| value = "_FUNC_(sketch, seed)", |
| extended = "Returns a human-readable summary of a given CpcSketch.") |
| @SuppressWarnings("javadoc") |
| public class SketchToStringUDF extends UDF { |
| |
| /** |
| * Get a summary of a given CpcSketch with explicit seed |
| * @param serializedSketch CpcSketch in a serialized binary form |
| * @param seed update seed |
| * @return text summary |
| */ |
| public String evaluate(final BytesWritable serializedSketch, final long seed) { |
| if (serializedSketch == null) { return null; } |
| final CpcSketch sketch = CpcSketch.heapify(Memory.wrap(serializedSketch.getBytes()), seed); |
| return sketch.toString(); |
| } |
| |
| /** |
| * Get a summary of a given CpcSketch using the default seed |
| * @param serializedSketch CpcSketch in a serialized binary form |
| * @return text summary |
| */ |
| public String evaluate(final BytesWritable serializedSketch) { |
| return evaluate(serializedSketch, DEFAULT_UPDATE_SEED); |
| } |
| |
| } |