| /* |
| * 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.pig.cpc; |
| |
| import static com.yahoo.sketches.Util.DEFAULT_UPDATE_SEED; |
| |
| import java.io.IOException; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.data.DataByteArray; |
| import org.apache.pig.data.Tuple; |
| |
| import com.yahoo.sketches.cpc.CpcSketch; |
| |
| /** |
| * This is a User Defined Function (UDF) for printing a human-readable summary of a given CpcSketch |
| * @author Alexander Saydakov |
| */ |
| public class SketchToString extends EvalFunc<String> { |
| |
| private final boolean isDetailed_; |
| private final long seed_; |
| |
| /** |
| * Prints only the sketch summary using the default seed. |
| */ |
| public SketchToString() { |
| this(false, DEFAULT_UPDATE_SEED); |
| } |
| |
| /** |
| * Prints the summary and details using the default seed. |
| * |
| * @param isDetailed flag to print the sketch detail |
| */ |
| public SketchToString(final String isDetailed) { |
| this(Boolean.parseBoolean(isDetailed), DEFAULT_UPDATE_SEED); |
| } |
| |
| /** |
| * Prints the summary and details using a given seed. |
| * |
| * @param isDetailed flag to print the sketch detail |
| * @param seed parameter for the hash function |
| */ |
| public SketchToString(final String isDetailed, final String seed) { |
| this(Boolean.parseBoolean(isDetailed), Long.parseLong(seed)); |
| } |
| |
| /** |
| * Internal constructor with primitive parameters. |
| * |
| * @param isDetailed flag to print the sketch detail |
| * @param seed parameter for the hash function |
| */ |
| private SketchToString(final boolean isDetailed, final long seed) { |
| isDetailed_ = isDetailed; |
| seed_ = seed; |
| } |
| |
| @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 CpcSketch sketch = CpcSketch.heapify(dba.get(), seed_); |
| return sketch.toString(isDetailed_); |
| } |
| |
| } |