| /* |
| * Copyright 2017, 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.pig.hll; |
| |
| import java.io.IOException; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.data.DataByteArray; |
| import org.apache.pig.data.Tuple; |
| |
| import com.yahoo.memory.Memory; |
| import com.yahoo.sketches.hll.HllSketch; |
| |
| /** |
| * This is a User Defined Function (UDF) for "pretty printing" the summary of an HllSketch |
| * |
| * @author Alexander Saydakov |
| */ |
| public class SketchToString extends EvalFunc<String> { |
| |
| private final boolean hllDetail_; |
| private final boolean auxDetail_; |
| |
| /** |
| * Prints only the sketch summary. |
| */ |
| public SketchToString() { |
| this(false, false); |
| } |
| |
| /** |
| * Prints the summary and details based on given input parameters. |
| * |
| * @param hllDetail flag to print the HLL sketch detail |
| * @param auxDetail flag to print the auxiliary detail |
| */ |
| public SketchToString(final String hllDetail, final String auxDetail) { |
| this(Boolean.parseBoolean(hllDetail), Boolean.parseBoolean(auxDetail)); |
| } |
| |
| /** |
| * Internal constructor with primitive parameters. |
| * |
| * @param hllDetail flag to print the HLL sketch detail |
| * @param auxDetail flag to print the auxiliary detail |
| */ |
| private SketchToString(final boolean hllDetail, final boolean auxDetail) { |
| super(); |
| hllDetail_ = hllDetail; |
| auxDetail_ = auxDetail; |
| } |
| |
| @Override |
| public String exec(final Tuple sketchTuple) throws IOException { |
| if ((sketchTuple == null) || (sketchTuple.size() == 0)) { |
| return null; |
| } |
| final DataByteArray dba = (DataByteArray) sketchTuple.get(0); |
| final HllSketch sketch = HllSketch.wrap(Memory.wrap(dba.get())); |
| return sketch.toString(true, hllDetail_, auxDetail_); |
| } |
| |
| } |