| /* |
| * 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.pig.theta; |
| |
| import static com.yahoo.sketches.pig.theta.PigUtil.tupleToSketch; |
| |
| import java.io.IOException; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.data.Tuple; |
| |
| import com.yahoo.sketches.Util; |
| import com.yahoo.sketches.theta.Sketch; |
| |
| /** |
| * Returns the unique count estimate of a sketch as a Double. |
| * |
| * @author LeeRhodes |
| */ |
| public class Estimate extends EvalFunc<Double> { |
| private final long seed_; |
| |
| /** |
| * Constructs with the DEFAULT_UPDATE_SEED used when deserializing the sketch. |
| */ |
| public Estimate() { |
| this(Util.DEFAULT_UPDATE_SEED); |
| } |
| |
| /** |
| * Constructs with the given seed. |
| * @param seedStr the string seed used when deserializing the sketch. |
| */ |
| public Estimate(final String seedStr) { |
| this(Long.parseLong(seedStr)); |
| } |
| |
| /** |
| * Constructs with the given seed. |
| * @param seed used when deserializing the sketch. |
| */ |
| public Estimate(final long seed) { |
| super(); |
| seed_ = seed; |
| } |
| |
| @Override |
| public Double exec(final Tuple sketchTuple) throws IOException { //throws is in API |
| if ((sketchTuple == null) || (sketchTuple.size() == 0)) { |
| return null; |
| } |
| final Sketch sketch = tupleToSketch(sketchTuple, seed_); |
| return sketch.getEstimate(); |
| } |
| } |