| /* |
| * Copyright 2019, Verizon Media. |
| * Licensed under the terms of the Apache License 2.0. See LICENSE file at the project root for terms. |
| */ |
| |
| package com.yahoo.sketches.hive.cpc; |
| |
| import static com.yahoo.sketches.Util.DEFAULT_UPDATE_SEED; |
| |
| import org.apache.hadoop.hive.ql.exec.Description; |
| import org.apache.hadoop.hive.ql.exec.UDF; |
| import org.apache.hadoop.io.BytesWritable; |
| |
| import com.yahoo.memory.Memory; |
| import com.yahoo.sketches.cpc.CpcSketch; |
| |
| @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); |
| } |
| |
| } |