content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file 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
   *
   * 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.
   */
  package org.apache.arrow.algorithm.misc;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  import org.apache.arrow.memory.BufferAllocator;
  import org.apache.arrow.memory.RootAllocator;
  import org.apache.arrow.vector.IntVector;
  import org.junit.jupiter.api.AfterEach;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  /** Test cases for {@link PartialSumUtils}. */
  public class TestPartialSumUtils {
  
    private static final int PARTIAL_SUM_VECTOR_LENGTH = 101;
  
    private static final int DELTA_VECTOR_LENGTH = 100;
  
    private BufferAllocator allocator;
  
    @BeforeEach
    public void prepare() {
      allocator = new RootAllocator(1024 * 1024);
    }
  
    @AfterEach
    public void shutdown() {
      allocator.close();
    }
  
    @Test
    public void testToPartialSumVector() {
      try (IntVector delta = new IntVector("delta", allocator);
          IntVector partialSum = new IntVector("partial sum", allocator)) {
        delta.allocateNew(DELTA_VECTOR_LENGTH);
        delta.setValueCount(DELTA_VECTOR_LENGTH);
  
        partialSum.allocateNew(PARTIAL_SUM_VECTOR_LENGTH);
  
        // populate delta vector
        for (int i = 0; i < delta.getValueCount(); i++) {
          delta.set(i, 3);
        }
  
        final long sumBase = 10;
        PartialSumUtils.toPartialSumVector(delta, partialSum, sumBase);
  
        // verify results
        assertEquals(PARTIAL_SUM_VECTOR_LENGTH, partialSum.getValueCount());
        for (int i = 0; i < partialSum.getValueCount(); i++) {
          assertEquals(i * 3L + sumBase, partialSum.get(i));
        }
      }
    }
  
    @Test
    public void testToDeltaVector() {
      try (IntVector partialSum = new IntVector("partial sum", allocator);
          IntVector delta = new IntVector("delta", allocator)) {
        partialSum.allocateNew(PARTIAL_SUM_VECTOR_LENGTH);
        partialSum.setValueCount(PARTIAL_SUM_VECTOR_LENGTH);
  
        delta.allocateNew(DELTA_VECTOR_LENGTH);
  
        // populate delta vector
        final int sumBase = 10;
        for (int i = 0; i < partialSum.getValueCount(); i++) {
          partialSum.set(i, sumBase + 3 * i);
        }
  
        PartialSumUtils.toDeltaVector(partialSum, delta);
  
        // verify results
        assertEquals(DELTA_VECTOR_LENGTH, delta.getValueCount());
        for (int i = 0; i < delta.getValueCount(); i++) {
          assertEquals(3, delta.get(i));
        }
      }
    }
  
    @Test
    public void testFindPositionInPartialSumVector() {
      try (IntVector partialSum = new IntVector("partial sum", allocator)) {
        partialSum.allocateNew(PARTIAL_SUM_VECTOR_LENGTH);
        partialSum.setValueCount(PARTIAL_SUM_VECTOR_LENGTH);
  
        // populate delta vector
        final int sumBase = 10;
        for (int i = 0; i < partialSum.getValueCount(); i++) {
          partialSum.set(i, sumBase + 3 * i);
        }
  
        // search and verify results
        for (int i = 0; i < PARTIAL_SUM_VECTOR_LENGTH - 1; i++) {
          assertEquals(
              i, PartialSumUtils.findPositionInPartialSumVector(partialSum, sumBase + 3 * i + 1));
        }
      }
    }
  
    @Test
    public void testFindPositionInPartialSumVectorNegative() {
      try (IntVector partialSum = new IntVector("partial sum", allocator)) {
        partialSum.allocateNew(PARTIAL_SUM_VECTOR_LENGTH);
        partialSum.setValueCount(PARTIAL_SUM_VECTOR_LENGTH);
  
        // populate delta vector
        final int sumBase = 10;
        for (int i = 0; i < partialSum.getValueCount(); i++) {
          partialSum.set(i, sumBase + 3 * i);
        }
  
        // search and verify results
        assertEquals(0, PartialSumUtils.findPositionInPartialSumVector(partialSum, sumBase));
        assertEquals(-1, PartialSumUtils.findPositionInPartialSumVector(partialSum, sumBase - 1));
        assertEquals(
            -1,
            PartialSumUtils.findPositionInPartialSumVector(
                partialSum, sumBase + 3 * (PARTIAL_SUM_VECTOR_LENGTH - 1)));
      }
    }
  }
  