src/test/java/org/apache/datasketches/hive/theta/EstimateSketchUDFTest.java

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 * 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
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 *
 * http://www.apache.org/licenses/LICENSE-2.0
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 * Unless required by applicable law or agreed to in writing,
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package org.apache.datasketches.hive.theta;

import static org.testng.AssertJUnit.assertEquals;

import org.apache.datasketches.theta.CompactSketch;
import org.apache.datasketches.theta.Sketches;
import org.apache.datasketches.theta.UpdateSketch;
import org.apache.hadoop.io.BytesWritable;
import org.testng.annotations.Test;

@SuppressWarnings({"javadoc"})
public class EstimateSketchUDFTest {

  @Test
  public void evaluateNull() {
    EstimateSketchUDF testObject = new EstimateSketchUDF();

    Double testResult = testObject.evaluate(null);

    assertEquals(testResult, 0.0);
  }

  @Test
  public void evaluateEmptyInput() {
    EstimateSketchUDF testObject = new EstimateSketchUDF();

    BytesWritable testInput = new BytesWritable();

    Double testResult = testObject.evaluate(testInput);

    assertEquals(testResult, 0.0);
  }

  @Test
  public void evaluateValid() {
    EstimateSketchUDF testObject = new EstimateSketchUDF();

    UpdateSketch sketch = Sketches.updateSketchBuilder().setNominalEntries(1024).build();
    for (int i = 0; i<128; i++) {
      sketch.update(i);
    }

    BytesWritable input = new BytesWritable(sketch.toByteArray());

    Double testResult = testObject.evaluate(input);

    assertEquals(128.0, testResult);

    CompactSketch compactSketch = sketch.compact(false, null);
    input = new BytesWritable(compactSketch.toByteArray());

    testResult = testObject.evaluate(input);

    assertEquals(128.0, testResult);
  }

  @Test
  public void evaluateValidExplicitSeed() {
    EstimateSketchUDF testObject = new EstimateSketchUDF();

    final long seed = 1;
    UpdateSketch sketch = Sketches.updateSketchBuilder().setSeed(seed).setNominalEntries(1024).build();
    for (int i = 0; i<128; i++) {
      sketch.update(i);
    }

    BytesWritable input = new BytesWritable(sketch.toByteArray());

    Double testResult = testObject.evaluate(input, seed);

    assertEquals(128.0, testResult);

    CompactSketch compactSketch = sketch.compact(false, null);
    input = new BytesWritable(compactSketch.toByteArray());

    testResult = testObject.evaluate(input, seed);

    assertEquals(128.0, testResult);
  }

  @Test
  public void evaluateRespectsByteLength() {
    // From Issue 50: https://github.com/apache/incubator-datasketches-hive/issues/50
    // In some instances, the BytesWritable buffer returned by getBytes() might be larger than the actual sketch bytes.
    // getLength() should give the correct length to use.
    //
    // https://github.com/apache/incubator-datasketches-hive/issues/50
    byte[] inputBytes = new byte[]{
        (byte) 0x01, (byte) 0x03, (byte) 0x03, (byte) 0x00,
        (byte) 0x00, (byte) 0x3a, (byte) 0xcc, (byte) 0x93,
        (byte) 0x15, (byte) 0xf9, (byte) 0x7d, (byte) 0xcb,
        (byte) 0xbd, (byte) 0x86, (byte) 0xa1, (byte) 0x05,
        (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00,
        (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00
    };
    BytesWritable input = new BytesWritable(inputBytes, 16);
    EstimateSketchUDF estimate = new EstimateSketchUDF();
    Double testResult = estimate.evaluate(input);
    assertEquals(1.0, testResult, 0.0);
  }
}