src/test/java/org/apache/datasketches/sampling/VarOptCrossLanguageTest.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
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
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 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
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package org.apache.datasketches.sampling;

import static org.apache.datasketches.common.UtilityIO.CHECK_CPP_FILES;
import static org.apache.datasketches.common.UtilityIO.CHECK_GO_FILES;
import static org.apache.datasketches.common.UtilityIO.CHECK_JAVA_FILES;
import static org.apache.datasketches.common.UtilityIO.GENERATE_JAVA_FILES;
import static org.apache.datasketches.common.UtilityIO.getFileBytes;
import static org.apache.datasketches.common.UtilityIO.putBytesToJavaPath;
import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertTrue;

import java.io.IOException;
import java.lang.foreign.MemorySegment;

import org.apache.datasketches.common.ArrayOfDoublesSerDe;
import org.apache.datasketches.common.ArrayOfLongsSerDe;
import org.apache.datasketches.common.ArrayOfStringsSerDe;
import org.apache.datasketches.common.UtilityIO.GroupLanguage;
import org.testng.annotations.Test;

/**
 * Serialize binary sketches to be tested by C++ code.
 * Test deserialization of binary sketches serialized by C++ code.
 */
public class VarOptCrossLanguageTest {
  static final double EPS = 1e-13;

  @Test(groups = {GENERATE_JAVA_FILES}, priority = 0)
  public void generateSketchesLong() throws IOException {
    final int[] nArr = {0, 1, 10, 100, 1000, 10_000, 100_000, 1_000_000};
    for (final int n: nArr) {
      final VarOptItemsSketch<Long> sk = VarOptItemsSketch.newInstance(32);
      for (int i = 1; i <= n; i++) {
        sk.update(Long.valueOf(i), 1.0);
      }
      putBytesToJavaPath("varopt_sketch_long_n" + n + "_java.sk",  sk.toByteArray(new ArrayOfLongsSerDe()));
    }
  }

  @Test(groups = {GENERATE_JAVA_FILES}, priority = 0)
  public void generateSketchStringExact() throws IOException {
    final VarOptItemsSketch<String> sketch = VarOptItemsSketch.newInstance(1024);
    for (int i = 1; i <= 200; ++i) {
      sketch.update(Integer.toString(i), 1000.0 / i);
    }
    putBytesToJavaPath("varopt_sketch_string_exact_java.sk",  sketch.toByteArray(new ArrayOfStringsSerDe()));
  }

  @Test(groups = {GENERATE_JAVA_FILES}, priority = 0)
  public void generateSketchLongSampling() throws IOException {
    final VarOptItemsSketch<Long> sketch = VarOptItemsSketch.newInstance(1024);
    for (long i = 0; i < 2000; ++i) {
      sketch.update(i, 1.0);
    }
    // negative heavy items to allow a simple predicate to filter
    sketch.update(-1L, 100000.0);
    sketch.update(-2L, 110000.0);
    sketch.update(-3L, 120000.0);
    putBytesToJavaPath("varopt_sketch_long_sampling_java.sk",  sketch.toByteArray(new ArrayOfLongsSerDe()));
  }

  @Test(groups = {GENERATE_JAVA_FILES}, priority = 0)
  public void generateUnionDoubleSampling() throws IOException {
    final int kSmall = 16;
    final int n1 = 32;
    final int n2 = 64;
    final int kMax = 128;

    // small k sketch, but sampling
    VarOptItemsSketch<Double> sketch = VarOptItemsSketch.newInstance(kSmall);
    for (int i = 0; i < n1; ++i) {
      sketch.update(1.0 * i, 1.0);
    }
    sketch.update(-1.0, n1 * n1); // negative heavy item to allow a simple predicate to filter


    final VarOptItemsUnion<Double> union = VarOptItemsUnion.newInstance(kMax);
    union.update(sketch);

    // another one, but different n to get a different per-item weight
    sketch = VarOptItemsSketch.newInstance(kSmall);
    for (int i = 0; i < n2; ++i) {
      sketch.update(1.0 * i, 1.0);
    }
    union.update(sketch);
    putBytesToJavaPath("varopt_union_double_sampling_java.sk",  union.toByteArray(new ArrayOfDoublesSerDe()));
  }

  @Test(groups = {CHECK_JAVA_FILES}, priority = 1)
  public void checkJava() {
    deserializeSketchLongs(GroupLanguage.JAVA);
    deserializeSketchStringsExact(GroupLanguage.JAVA);
    deserializeSketdhLongsSampling(GroupLanguage.JAVA);
    deserializeUnionDoubleSampling(GroupLanguage.JAVA);
  }

  @Test(groups = {CHECK_CPP_FILES})
  public void checkCpp() {
    deserializeSketchLongs(GroupLanguage.CPP);
    deserializeSketchStringsExact(GroupLanguage.CPP);
    deserializeSketdhLongsSampling(GroupLanguage.CPP);
    deserializeUnionDoubleSampling(GroupLanguage.CPP);
  }

  @Test(groups = {CHECK_GO_FILES})
  public void checkGo() {
    deserializeSketchLongs(GroupLanguage.GO);
    deserializeSketchStringsExact(GroupLanguage.GO);
    deserializeSketdhLongsSampling(GroupLanguage.GO);
    deserializeUnionDoubleSampling(GroupLanguage.GO);
  }

  private static void deserializeSketchLongs(final GroupLanguage lang) {
    final int[] nArr = {0, 1, 10, 100, 1000, 10000, 100000, 1000000};
    for (final int n: nArr) {
      final String fileName = "varopt_sketch_long_n" + n + lang.sfx + ".sk";
      final byte[] bytes = getFileBytes(lang.pth, fileName);
      if (bytes.length == 0) { continue; }
      //System.out.println(fileName);
      final VarOptItemsSketch<Long> sk = VarOptItemsSketch.heapify(MemorySegment.ofArray(bytes), new ArrayOfLongsSerDe());
      assertEquals(sk.getK(), 32);
      assertEquals(sk.getN(), n);
      assertEquals(sk.getNumSamples(), n > 10 ? 32 : n);
    }
  }

  @SuppressWarnings("unused")
  private static void deserializeSketchStringsExact(final GroupLanguage lang) {
    final String fileName = "varopt_sketch_string_exact" + lang.sfx + ".sk";
    final byte[] bytes = getFileBytes(lang.pth, fileName);
    if (bytes.length == 0) { return; }
    //System.out.println(fileName);
    final VarOptItemsSketch<String> sk = VarOptItemsSketch.heapify(MemorySegment.ofArray(bytes), new ArrayOfStringsSerDe());
    assertEquals(sk.getK(), 1024);
    assertEquals(sk.getN(), 200);
    assertEquals(sk.getNumSamples(), 200);
    final SampleSubsetSummary ss = sk.estimateSubsetSum(item -> true);
    double weight = 0;
    for (int i = 1; i <= 200; ++i) {
      weight += 1000.0 / i;
    }
    assertEquals(ss.getTotalSketchWeight(), weight, EPS);
  }

  @SuppressWarnings("unused")
  private static void deserializeSketdhLongsSampling(final GroupLanguage lang) {
    String fileName = "varopt_sketch_long_sampling" + lang.sfx + ".sk";
    final byte[] bytes = getFileBytes(lang.pth, fileName);
    if (bytes.length == 0) { return; }
    //System.out.println(fileName);
    final VarOptItemsSketch<Long> sk = VarOptItemsSketch.heapify(MemorySegment.ofArray(bytes), new ArrayOfLongsSerDe());
    assertEquals(sk.getK(), 1024);
    assertEquals(sk.getN(), 2003);
    assertEquals(sk.getNumSamples(), 1024);
    SampleSubsetSummary ss = sk.estimateSubsetSum(item -> true);
    assertEquals(ss.getTotalSketchWeight(), 332000.0, EPS);

    ss = sk.estimateSubsetSum(item -> item < 0);
    assertEquals(ss.getEstimate(), 330000.0); // heavy item, weight is exact

    ss = sk.estimateSubsetSum(item -> item >= 0);
    assertEquals(ss.getEstimate(), 2000.0, EPS);
  }

  private static void deserializeUnionDoubleSampling(final GroupLanguage lang) {
    final String fileName = "varopt_union_double_sampling" + lang.sfx + ".sk";
    final byte[] bytes = getFileBytes(lang.pth, fileName);
    if (bytes.length == 0) { return; }
    //System.out.println(fileName);
    final VarOptItemsUnion<Double> u = VarOptItemsUnion.heapify(MemorySegment.ofArray(bytes), new ArrayOfDoublesSerDe());

    // must reduce k in the process
    final VarOptItemsSketch<Double> sk = u.getResult();
    assertTrue(sk.getK() < 128);
    assertEquals(sk.getN(), 97);

    // light items, ignoring the heavy one
    final SampleSubsetSummary ss = sk.estimateSubsetSum(item -> item >= 0);
    assertEquals(ss.getEstimate(), 96.0, EPS);
    assertEquals(ss.getTotalSketchWeight(), 96.0 + 1024.0, EPS);
  }

}