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.vector.util;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNull;
  
  import java.nio.charset.StandardCharsets;
  import org.apache.arrow.memory.BufferAllocator;
  import org.apache.arrow.memory.RootAllocator;
  import org.apache.arrow.memory.util.ArrowBufPointer;
  import org.apache.arrow.vector.IntVector;
  import org.apache.arrow.vector.VarCharVector;
  import org.junit.jupiter.api.AfterEach;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  /** Test cases for {@link ElementAddressableVectorIterator}. */
  public class TestElementAddressableVectorIterator {
  
    private final int VECTOR_LENGTH = 100;
  
    private BufferAllocator allocator;
  
    @BeforeEach
    public void prepare() {
      allocator = new RootAllocator(1024 * 1024);
    }
  
    @AfterEach
    public void shutdown() {
      allocator.close();
    }
  
    @Test
    public void testIterateIntVector() {
      try (IntVector intVector = new IntVector("", allocator)) {
        intVector.allocateNew(VECTOR_LENGTH);
        intVector.setValueCount(VECTOR_LENGTH);
  
        // prepare data in sorted order
        for (int i = 0; i < VECTOR_LENGTH; i++) {
          if (i == 0) {
            intVector.setNull(i);
          } else {
            intVector.set(i, i);
          }
        }
  
        // iterate
        ElementAddressableVectorIterator<IntVector> it =
            new ElementAddressableVectorIterator<>(intVector);
        int index = 0;
        while (it.hasNext()) {
          ArrowBufPointer pt;
  
          if (index % 2 == 0) {
            // use populated pointer.
            pt = new ArrowBufPointer();
            it.next(pt);
          } else {
            // use iterator inner pointer
            pt = it.next();
          }
          if (index == 0) {
            assertNull(pt.getBuf());
          } else {
            assertEquals(index, pt.getBuf().getInt(pt.getOffset()));
          }
          index += 1;
        }
      }
    }
  
    @Test
    public void testIterateVarCharVector() {
      try (VarCharVector strVector = new VarCharVector("", allocator)) {
        strVector.allocateNew(VECTOR_LENGTH * 10, VECTOR_LENGTH);
        strVector.setValueCount(VECTOR_LENGTH);
  
        // prepare data in sorted order
        for (int i = 0; i < VECTOR_LENGTH; i++) {
          if (i == 0) {
            strVector.setNull(i);
          } else {
            strVector.set(i, String.valueOf(i).getBytes(StandardCharsets.UTF_8));
          }
        }
  
        // iterate
        ElementAddressableVectorIterator<VarCharVector> it =
            new ElementAddressableVectorIterator<>(strVector);
        int index = 0;
        while (it.hasNext()) {
          ArrowBufPointer pt;
  
          if (index % 2 == 0) {
            // use populated pointer.
            pt = new ArrowBufPointer();
            it.next(pt);
          } else {
            // use iterator inner pointer
            pt = it.next();
          }
  
          if (index == 0) {
            assertNull(pt.getBuf());
          } else {
            String expected = String.valueOf(index);
            byte[] actual = new byte[expected.length()];
            assertEquals(expected.length(), pt.getLength());
  
            pt.getBuf().getBytes(pt.getOffset(), actual);
            assertEquals(expected, new String(actual, StandardCharsets.UTF_8));
          }
          index += 1;
        }
      }
    }
  }
  