hbase-common/src/test/java/org/apache/hadoop/hbase/TestCellUtil.java

/**
 * 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.hadoop.hbase;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.math.BigDecimal;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.NavigableMap;
import java.util.TreeMap;
import org.apache.hadoop.hbase.testclassification.MiscTests;
import org.apache.hadoop.hbase.testclassification.SmallTests;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Assert;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.mockito.Mockito;

@Category({MiscTests.class, SmallTests.class})
public class TestCellUtil {
  /**
   * CellScannable used in test. Returns a {@link TestCellScanner}
   */
  private static class TestCellScannable implements CellScannable {
    private final int cellsCount;
    TestCellScannable(final int cellsCount) {
      this.cellsCount = cellsCount;
    }
    @Override
    public CellScanner cellScanner() {
      return new TestCellScanner(this.cellsCount);
    }
  }

  /**
   * CellScanner used in test.
   */
  private static class TestCellScanner implements CellScanner {
    private int count = 0;
    private Cell current = null;
    private final int cellsCount;

    TestCellScanner(final int cellsCount) {
      this.cellsCount = cellsCount;
    }

    @Override
    public Cell current() {
      return this.current;
    }

    @Override
    public boolean advance() throws IOException {
      if (this.count < cellsCount) {
        this.current = new TestCell(this.count);
        this.count++;
        return true;
      }
      return false;
    }
  }

  /**
   * Cell used in test. Has row only.
   */
  private static class TestCell implements Cell {
    private final byte [] row;

    TestCell(final int i) {
      this.row = Bytes.toBytes(i);
    }

    @Override
    public byte[] getRowArray() {
      return this.row;
    }

    @Override
    public int getRowOffset() {
      return 0;
    }

    @Override
    public short getRowLength() {
      return (short)this.row.length;
    }

    @Override
    public byte[] getFamilyArray() {
      // TODO Auto-generated method stub
      return null;
    }

    @Override
    public int getFamilyOffset() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public byte getFamilyLength() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public byte[] getQualifierArray() {
      // TODO Auto-generated method stub
      return null;
    }

    @Override
    public int getQualifierOffset() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public int getQualifierLength() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public long getTimestamp() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public byte getTypeByte() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public byte[] getValueArray() {
      // TODO Auto-generated method stub
      return null;
    }

    @Override
    public int getValueOffset() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public int getValueLength() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public byte[] getTagsArray() {
      // TODO Auto-generated method stub
      return null;
    }

    @Override
    public int getTagsOffset() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public long getSequenceId() {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public int getTagsLength() {
      // TODO Auto-generated method stub
      return 0;
    }
  }

  /**
   * Was overflowing if 100k or so lists of cellscanners to return.
   */
  @Test
  public void testCreateCellScannerOverflow() throws IOException {
    consume(doCreateCellScanner(1, 1), 1 * 1);
    consume(doCreateCellScanner(3, 0), 3 * 0);
    consume(doCreateCellScanner(3, 3), 3 * 3);
    consume(doCreateCellScanner(0, 1), 0 * 1);
    // Do big number. See HBASE-11813 for why.
    final int hundredK = 100000;
    consume(doCreateCellScanner(hundredK, 0), hundredK * 0);
    consume(doCreateCellArray(1), 1);
    consume(doCreateCellArray(0), 0);
    consume(doCreateCellArray(3), 3);
    List<CellScannable> cells = new ArrayList<>(hundredK);
    for (int i = 0; i < hundredK; i++) {
      cells.add(new TestCellScannable(1));
    }
    consume(CellUtil.createCellScanner(cells), hundredK * 1);
    NavigableMap<byte [], List<Cell>> m = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    List<Cell> cellArray = new ArrayList<>(hundredK);
    for (int i = 0; i < hundredK; i++) {
      cellArray.add(new TestCell(i));
    }
    m.put(new byte [] {'f'}, cellArray);
    consume(CellUtil.createCellScanner(m), hundredK * 1);
  }

  private CellScanner doCreateCellArray(final int itemsPerList) {
    Cell [] cells = new Cell [itemsPerList];
    for (int i = 0; i < itemsPerList; i++) {
      cells[i] = new TestCell(i);
    }
    return CellUtil.createCellScanner(cells);
  }

  private CellScanner doCreateCellScanner(final int listsCount, final int itemsPerList)
  throws IOException {
    List<CellScannable> cells = new ArrayList<>(listsCount);
    for (int i = 0; i < listsCount; i++) {
      CellScannable cs = new CellScannable() {
        @Override
        public CellScanner cellScanner() {
          return new TestCellScanner(itemsPerList);
        }
      };
      cells.add(cs);
    }
    return CellUtil.createCellScanner(cells);
  }

  private void consume(final CellScanner scanner, final int expected) throws IOException {
    int count = 0;
    while (scanner.advance()) {
      count++;
    }
    Assert.assertEquals(expected, count);
  }

  @Test
  public void testOverlappingKeys() {
    byte[] empty = HConstants.EMPTY_BYTE_ARRAY;
    byte[] a = Bytes.toBytes("a");
    byte[] b = Bytes.toBytes("b");
    byte[] c = Bytes.toBytes("c");
    byte[] d = Bytes.toBytes("d");

    // overlaps
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, b, a, b));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, c, a, b));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, b, a, c));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(b, c, a, c));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, c, b, c));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, d, b, c));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(b, c, a, d));

    Assert.assertTrue(PrivateCellUtil.overlappingKeys(empty, b, a, b));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(empty, b, a, c));

    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, b, empty, b));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, b, empty, c));

    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, empty, a, b));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, empty, a, c));

    Assert.assertTrue(PrivateCellUtil.overlappingKeys(a, b, empty, empty));
    Assert.assertTrue(PrivateCellUtil.overlappingKeys(empty, empty, a, b));

    // non overlaps
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(a, b, c, d));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(c, d, a, b));

    Assert.assertFalse(PrivateCellUtil.overlappingKeys(b, c, c, d));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(b, c, c, empty));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(b, c, d, empty));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(c, d, b, c));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(c, empty, b, c));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(d, empty, b, c));

    Assert.assertFalse(PrivateCellUtil.overlappingKeys(b, c, a, b));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(b, c, empty, b));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(b, c, empty, a));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(a,b, b, c));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(empty, b, b, c));
    Assert.assertFalse(PrivateCellUtil.overlappingKeys(empty, a, b, c));
  }

  @Test
  public void testFindCommonPrefixInFlatKey() {
    // The whole key matching case
    KeyValue kv1 = new KeyValue(Bytes.toBytes("r1"), Bytes.toBytes("f1"),
        Bytes.toBytes("q1"), null);
    Assert.assertEquals(kv1.getKeyLength(),
      PrivateCellUtil.findCommonPrefixInFlatKey(kv1, kv1, true, true));
    Assert.assertEquals(kv1.getKeyLength(),
      PrivateCellUtil.findCommonPrefixInFlatKey(kv1, kv1, false, true));
    Assert.assertEquals(kv1.getKeyLength() - KeyValue.TIMESTAMP_TYPE_SIZE,
      PrivateCellUtil.findCommonPrefixInFlatKey(kv1, kv1, true, false));
    // The rk length itself mismatch
    KeyValue kv2 = new KeyValue(Bytes.toBytes("r12"), Bytes.toBytes("f1"),
        Bytes.toBytes("q1"), null);
    Assert.assertEquals(1, PrivateCellUtil.findCommonPrefixInFlatKey(kv1, kv2, true, true));
    // part of rk is same
    KeyValue kv3 = new KeyValue(Bytes.toBytes("r14"), Bytes.toBytes("f1"),
        Bytes.toBytes("q1"), null);
    Assert.assertEquals(KeyValue.ROW_LENGTH_SIZE + Bytes.toBytes("r1").length,
      PrivateCellUtil.findCommonPrefixInFlatKey(kv2, kv3, true, true));
    // entire rk is same but different cf name
    KeyValue kv4 = new KeyValue(Bytes.toBytes("r14"), Bytes.toBytes("f2"),
        Bytes.toBytes("q1"), null);
    Assert.assertEquals(KeyValue.ROW_LENGTH_SIZE + kv3.getRowLength() + KeyValue.FAMILY_LENGTH_SIZE
        + Bytes.toBytes("f").length,
        PrivateCellUtil.findCommonPrefixInFlatKey(kv3, kv4, false, true));
    // rk and family are same and part of qualifier
    KeyValue kv5 = new KeyValue(Bytes.toBytes("r14"), Bytes.toBytes("f2"),
        Bytes.toBytes("q123"), null);
    Assert.assertEquals(KeyValue.ROW_LENGTH_SIZE + kv3.getRowLength() + KeyValue.FAMILY_LENGTH_SIZE
        + kv4.getFamilyLength() + kv4.getQualifierLength(),
        PrivateCellUtil.findCommonPrefixInFlatKey(kv4, kv5, true, true));
    // rk, cf and q are same. ts differs
    KeyValue kv6 = new KeyValue(Bytes.toBytes("rk"), 1234L);
    KeyValue kv7 = new KeyValue(Bytes.toBytes("rk"), 1235L);
    // only last byte out of 8 ts bytes in ts part differs
    Assert.assertEquals(KeyValue.ROW_LENGTH_SIZE + kv6.getRowLength() + KeyValue.FAMILY_LENGTH_SIZE
        + kv6.getFamilyLength() + kv6.getQualifierLength() + 7,
        PrivateCellUtil.findCommonPrefixInFlatKey(kv6, kv7, true, true));
    // rk, cf, q and ts are same. Only type differs
    KeyValue kv8 = new KeyValue(Bytes.toBytes("rk"), 1234L, KeyValue.Type.Delete);
    Assert.assertEquals(KeyValue.ROW_LENGTH_SIZE + kv6.getRowLength() + KeyValue.FAMILY_LENGTH_SIZE
        + kv6.getFamilyLength() + kv6.getQualifierLength() + KeyValue.TIMESTAMP_SIZE,
        PrivateCellUtil.findCommonPrefixInFlatKey(kv6, kv8, true, true));
    // With out TS_TYPE check
    Assert.assertEquals(KeyValue.ROW_LENGTH_SIZE + kv6.getRowLength() + KeyValue.FAMILY_LENGTH_SIZE
        + kv6.getFamilyLength() + kv6.getQualifierLength(),
        PrivateCellUtil.findCommonPrefixInFlatKey(kv6, kv8, true, false));
  }

  /**
   * Assert CellUtil makes Cell toStrings same way we do KeyValue toStrings.
   */
  @Test
  public void testToString() {
    byte [] row = Bytes.toBytes("row");
    long ts = 123L;
    // Make a KeyValue and a Cell and see if same toString result.
    KeyValue kv = new KeyValue(row, HConstants.EMPTY_BYTE_ARRAY, HConstants.EMPTY_BYTE_ARRAY,
        ts, KeyValue.Type.Minimum, HConstants.EMPTY_BYTE_ARRAY);
    Cell cell = CellUtil.createCell(row, HConstants.EMPTY_BYTE_ARRAY, HConstants.EMPTY_BYTE_ARRAY,
        ts, KeyValue.Type.Minimum.getCode(), HConstants.EMPTY_BYTE_ARRAY);
    String cellToString = CellUtil.getCellKeyAsString(cell);
    assertEquals(kv.toString(), cellToString);
    // Do another w/ non-null family.
    byte [] f = new byte [] {'f'};
    byte [] q = new byte [] {'q'};
    kv = new KeyValue(row, f, q, ts, KeyValue.Type.Minimum, HConstants.EMPTY_BYTE_ARRAY);
    cell = CellUtil.createCell(row, f, q, ts, KeyValue.Type.Minimum.getCode(),
        HConstants.EMPTY_BYTE_ARRAY);
    cellToString = CellUtil.getCellKeyAsString(cell);
    assertEquals(kv.toString(), cellToString);

  }

  @Test
  public void testToString1() {
    String row = "test.row";
    String family = "test.family";
    String qualifier = "test.qualifier";
    long timestamp = 42;
    KeyValue.Type type = KeyValue.Type.Put;
    String value = "test.value";
    long seqId = 1042;

    Cell cell = CellUtil.createCell(Bytes.toBytes(row), Bytes.toBytes(family),
      Bytes.toBytes(qualifier), timestamp, type.getCode(), Bytes.toBytes(value), seqId);

    String nonVerbose = CellUtil.toString(cell, false);
    String verbose = CellUtil.toString(cell, true);

    System.out.println("nonVerbose=" + nonVerbose);
    System.out.println("verbose=" + verbose);

    Assert.assertEquals(
        String.format("%s/%s:%s/%d/%s/vlen=%s/seqid=%s",
          row, family, qualifier, timestamp, type.toString(),
          Bytes.toBytes(value).length, seqId),
        nonVerbose);

    Assert.assertEquals(
      String.format("%s/%s:%s/%d/%s/vlen=%s/seqid=%s/%s",
        row, family, qualifier, timestamp, type.toString(), Bytes.toBytes(value).length,
        seqId, value),
      verbose);

    // TODO: test with tags
  }

  @Test
  public void testCloneCellFieldsFromByteBufferedCell() {
    byte[] r = Bytes.toBytes("row1");
    byte[] f = Bytes.toBytes("cf1");
    byte[] q = Bytes.toBytes("qual1");
    byte[] v = Bytes.toBytes("val1");
    byte[] tags = Bytes.toBytes("tag1");
    KeyValue kv =
        new KeyValue(r, f, q, 0, q.length, 1234L, KeyValue.Type.Put, v, 0, v.length, tags);
    ByteBuffer buffer = ByteBuffer.wrap(kv.getBuffer());
    Cell bbCell = new ByteBufferKeyValue(buffer, 0, buffer.remaining());
    byte[] rDest = CellUtil.cloneRow(bbCell);
    assertTrue(Bytes.equals(r, rDest));
    byte[] fDest = CellUtil.cloneFamily(bbCell);
    assertTrue(Bytes.equals(f, fDest));
    byte[] qDest = CellUtil.cloneQualifier(bbCell);
    assertTrue(Bytes.equals(q, qDest));
    byte[] vDest = CellUtil.cloneValue(bbCell);
    assertTrue(Bytes.equals(v, vDest));
    byte[] tDest = new byte[tags.length];
    PrivateCellUtil.copyTagsTo(bbCell, tDest, 0);
    assertTrue(Bytes.equals(tags, tDest));
  }

  @Test
  public void testMatchingCellFieldsFromByteBufferedCell() {
    byte[] r = Bytes.toBytes("row1");
    byte[] f = Bytes.toBytes("cf1");
    byte[] q1 = Bytes.toBytes("qual1");
    byte[] q2 = Bytes.toBytes("qual2");
    byte[] v = Bytes.toBytes("val1");
    byte[] tags = Bytes.toBytes("tag1");
    KeyValue kv =
        new KeyValue(r, f, q1, 0, q1.length, 1234L, KeyValue.Type.Put, v, 0, v.length, tags);
    ByteBuffer buffer = ByteBuffer.wrap(kv.getBuffer());
    Cell bbCell1 = new ByteBufferKeyValue(buffer, 0, buffer.remaining());
    kv = new KeyValue(r, f, q2, 0, q2.length, 1234L, KeyValue.Type.Put, v, 0, v.length, tags);
    buffer = ByteBuffer.wrap(kv.getBuffer());
    Cell bbCell2 = new ByteBufferKeyValue(buffer, 0, buffer.remaining());
    assertTrue(CellUtil.matchingRows(bbCell1, bbCell2));
    assertTrue(CellUtil.matchingRows(kv, bbCell2));
    assertTrue(CellUtil.matchingRows(bbCell1, r));
    assertTrue(CellUtil.matchingFamily(bbCell1, bbCell2));
    assertTrue(CellUtil.matchingFamily(kv, bbCell2));
    assertTrue(CellUtil.matchingFamily(bbCell1, f));
    assertFalse(CellUtil.matchingQualifier(bbCell1, bbCell2));
    assertTrue(CellUtil.matchingQualifier(kv, bbCell2));
    assertTrue(CellUtil.matchingQualifier(bbCell1, q1));
    assertTrue(CellUtil.matchingQualifier(bbCell2, q2));
    assertTrue(CellUtil.matchingValue(bbCell1, bbCell2));
    assertTrue(CellUtil.matchingValue(kv, bbCell2));
    assertTrue(CellUtil.matchingValue(bbCell1, v));
    assertFalse(CellUtil.matchingColumn(bbCell1, bbCell2));
    assertTrue(CellUtil.matchingColumn(kv, bbCell2));
    assertTrue(CellUtil.matchingColumn(bbCell1, f, q1));
    assertTrue(CellUtil.matchingColumn(bbCell2, f, q2));
  }

  @Test
  public void testCellFieldsAsPrimitiveTypesFromByteBufferedCell() {
    int ri = 123;
    byte[] r = Bytes.toBytes(ri);
    byte[] f = Bytes.toBytes("cf1");
    byte[] q = Bytes.toBytes("qual1");
    long vl = 10981L;
    byte[] v = Bytes.toBytes(vl);
    KeyValue kv = new KeyValue(r, f, q, v);
    ByteBuffer buffer = ByteBuffer.wrap(kv.getBuffer());
    Cell bbCell = new ByteBufferKeyValue(buffer, 0, buffer.remaining());
    assertEquals(ri, PrivateCellUtil.getRowAsInt(bbCell));
    assertEquals(vl, PrivateCellUtil.getValueAsLong(bbCell));
    double vd = 3005.5;
    v = Bytes.toBytes(vd);
    kv = new KeyValue(r, f, q, v);
    buffer = ByteBuffer.wrap(kv.getBuffer());
    bbCell = new ByteBufferKeyValue(buffer, 0, buffer.remaining());
    assertEquals(vd, PrivateCellUtil.getValueAsDouble(bbCell), 0.0);
    BigDecimal bd = new BigDecimal(9999);
    v = Bytes.toBytes(bd);
    kv = new KeyValue(r, f, q, v);
    buffer = ByteBuffer.wrap(kv.getBuffer());
    bbCell = new ByteBufferKeyValue(buffer, 0, buffer.remaining());
    assertEquals(bd, PrivateCellUtil.getValueAsBigDecimal(bbCell));
  }

  @Test
  public void testWriteCell() throws IOException {
    byte[] r = Bytes.toBytes("row1");
    byte[] f = Bytes.toBytes("cf1");
    byte[] q1 = Bytes.toBytes("qual1");
    byte[] q2 = Bytes.toBytes("qual2");
    byte[] v = Bytes.toBytes("val1");
    byte[] tags = Bytes.toBytes("tag1");
    KeyValue kv =
        new KeyValue(r, f, q1, 0, q1.length, 1234L, KeyValue.Type.Put, v, 0, v.length, tags);
    NonExtendedCell nonExtCell = new NonExtendedCell(kv);
    ByteArrayOutputStream os = new ByteArrayOutputStream();
    int writeCell = PrivateCellUtil.writeCell(nonExtCell, os, true);
    byte[] byteArray = os.toByteArray();
    KeyValue res = new KeyValue(byteArray);
    assertTrue(CellUtil.equals(kv, res));
  }

  @Test
  public void testGetType() throws IOException {
    Cell c = Mockito.mock(Cell.class);
    Mockito.when(c.getType()).thenCallRealMethod();
    for (Cell.Type type : Cell.Type.values()) {
      Mockito.when(c.getTypeByte()).thenReturn(type.getCode());
      assertEquals(type, c.getType());
    }

    try {
      Mockito.when(c.getTypeByte()).thenReturn(KeyValue.Type.Maximum.getCode());
      c.getType();
      fail("The code of Maximum can't be handled by Cell.Type");
    } catch(UnsupportedOperationException e) {
    }

    try {
      Mockito.when(c.getTypeByte()).thenReturn(KeyValue.Type.Minimum.getCode());
      c.getType();
      fail("The code of Maximum can't be handled by Cell.Type");
    } catch(UnsupportedOperationException e) {
    }
  }

  private static class NonExtendedCell implements Cell {
    private KeyValue kv;

    public NonExtendedCell(KeyValue kv) {
      this.kv = kv;
    }

    @Override
    public byte[] getRowArray() {
      return this.kv.getRowArray();
    }

    @Override
    public int getRowOffset() {
      return this.kv.getRowOffset();
    }

    @Override
    public short getRowLength() {
      return this.kv.getRowLength();
    }

    @Override
    public byte[] getFamilyArray() {
      return this.kv.getFamilyArray();
    }

    @Override
    public int getFamilyOffset() {
      return this.kv.getFamilyOffset();
    }

    @Override
    public byte getFamilyLength() {
      return this.kv.getFamilyLength();
    }

    @Override
    public byte[] getQualifierArray() {
      return this.kv.getQualifierArray();
    }

    @Override
    public int getQualifierOffset() {
      return this.kv.getQualifierOffset();
    }

    @Override
    public int getQualifierLength() {
      return this.kv.getQualifierLength();
    }

    @Override
    public long getTimestamp() {
      return this.kv.getTimestamp();
    }

    @Override
    public byte getTypeByte() {
      return this.kv.getTypeByte();
    }

    @Override
    public long getSequenceId() {
      return this.kv.getSequenceId();
    }

    @Override
    public byte[] getValueArray() {
      return this.kv.getValueArray();
    }

    @Override
    public int getValueOffset() {
      return this.kv.getValueOffset();
    }

    @Override
    public int getValueLength() {
      return this.kv.getValueLength();
    }

    @Override
    public byte[] getTagsArray() {
      return this.kv.getTagsArray();
    }

    @Override
    public int getTagsOffset() {
      return this.kv.getTagsOffset();
    }

    @Override
    public int getTagsLength() {
      return this.kv.getTagsLength();
    }
  }
}