How to use

isNull

method

in

io.prestosql.spi.block.ColumnarRow

@Override
public void appendNext(PageBuilder pageBuilder, int outputChannelOffset)
{
  checkState(columnarRow != null, "columnarRow is null");
  for (int i = 0; i < fieldTypes.size(); i++) {
    BlockBuilder blockBuilder = pageBuilder.getBlockBuilder(outputChannelOffset + i);
    if (columnarRow.isNull(position)) {
      blockBuilder.appendNull();
    }
    else {
      fieldTypes.get(i).appendTo(columnarRow.getField(i), nonNullPosition, blockBuilder);
    }
  }
  if (!columnarRow.isNull(position)) {
    nonNullPosition++;
  }
  position++;
}

@Override
public void appendNext(PageBuilder pageBuilder, int outputChannelOffset)
{
  checkState(columnarRow != null, "columnarRow is null");
  for (int i = 0; i < fieldTypes.size(); i++) {
    BlockBuilder blockBuilder = pageBuilder.getBlockBuilder(outputChannelOffset + i);
    if (columnarRow.isNull(position)) {
      blockBuilder.appendNull();
    }
    else {
      fieldTypes.get(i).appendTo(columnarRow.getField(i), nonNullPosition, blockBuilder);
    }
  }
  if (!columnarRow.isNull(position)) {
    nonNullPosition++;
  }
  position++;
}

private void writeColumnarRow(ColumnarRow columnarRow)
{
  // record nulls
  for (int position = 0; position < columnarRow.getPositionCount(); position++) {
    boolean present = !columnarRow.isNull(position);
    presentStream.writeBoolean(present);
    if (present) {
      nonNullValueCount++;
    }
  }
  // write field values
  for (int i = 0; i < structFields.size(); i++) {
    ColumnWriter columnWriter = structFields.get(i);
    Block fieldBlock = columnarRow.getField(i);
    if (fieldBlock.getPositionCount() > 0) {
      columnWriter.writeBlock(fieldBlock);
    }
  }
}

private void writeColumnarRow(ColumnarRow columnarRow)
{
  // record nulls
  for (int position = 0; position < columnarRow.getPositionCount(); position++) {
    boolean present = !columnarRow.isNull(position);
    presentStream.writeBoolean(present);
    if (present) {
      nonNullValueCount++;
    }
  }
  // write field values
  for (int i = 0; i < structFields.size(); i++) {
    ColumnWriter columnWriter = structFields.get(i);
    Block fieldBlock = columnarRow.getField(i);
    if (fieldBlock.getPositionCount() > 0) {
      columnWriter.writeBlock(fieldBlock);
    }
  }
}

private static <T> void assertColumnarRow(Block block, T[] expectedValues)
{
  ColumnarRow columnarRow = toColumnarRow(block);
  assertEquals(columnarRow.getPositionCount(), expectedValues.length);
  for (int fieldId = 0; fieldId < FIELD_COUNT; fieldId++) {
    Block fieldBlock = columnarRow.getField(fieldId);
    int elementsPosition = 0;
    for (int position = 0; position < expectedValues.length; position++) {
      T expectedRow = expectedValues[position];
      assertEquals(columnarRow.isNull(position), expectedRow == null);
      if (expectedRow == null) {
        continue;
      }
      Object expectedElement = Array.get(expectedRow, fieldId);
      assertBlockPosition(fieldBlock, elementsPosition, expectedElement);
      elementsPosition++;
    }
  }
}

private static <T> void assertColumnarRow(Block block, T[] expectedValues)
{
  ColumnarRow columnarRow = toColumnarRow(block);
  assertEquals(columnarRow.getPositionCount(), expectedValues.length);
  for (int fieldId = 0; fieldId < FIELD_COUNT; fieldId++) {
    Block fieldBlock = columnarRow.getField(fieldId);
    int elementsPosition = 0;
    for (int position = 0; position < expectedValues.length; position++) {
      T expectedRow = expectedValues[position];
      assertEquals(columnarRow.isNull(position), expectedRow == null);
      if (expectedRow == null) {
        continue;
      }
      Object expectedElement = Array.get(expectedRow, fieldId);
      assertBlockPosition(fieldBlock, elementsPosition, expectedElement);
      elementsPosition++;
    }
  }
}

  @Override
  public Block apply(Block block)
  {
    ColumnarRow rowBlock = toColumnarRow(block);
    Block[] fields = new Block[coercers.length];
    int[] ids = new int[rowBlock.getField(0).getPositionCount()];
    for (int i = 0; i < coercers.length; i++) {
      if (coercers[i] != null) {
        fields[i] = coercers[i].apply(rowBlock.getField(i));
      }
      else if (i < rowBlock.getFieldCount()) {
        fields[i] = rowBlock.getField(i);
      }
      else {
        fields[i] = new DictionaryBlock(nullBlocks[i], ids);
      }
    }
    boolean[] valueIsNull = new boolean[rowBlock.getPositionCount()];
    for (int i = 0; i < rowBlock.getPositionCount(); i++) {
      valueIsNull[i] = rowBlock.isNull(i);
    }
    return RowBlock.fromFieldBlocks(valueIsNull.length, Optional.of(valueIsNull), fields);
  }
}