OAP ParquetDataFile and Cache

ParquetDataFile.scala

val iterator = reader.iteratorWithRowIds(requiredIds, rowIds)
      .asInstanceOf[OapCompletionIterator[InternalRow]]
    val result = ArrayBuffer[Int]()
    while (iterator.hasNext) {
      val row: InternalRow = iterator.next()
      assert(row.numFields == 2)
      result += row.getInt(0)
    }

DataFile.scala

private[oap] class OapCompletionIterator[T](inner: Iterator[T], completionFunction: => Unit)
    extends Iterator[T] with Closeable {

  private[this] var completed = false
  override def hasNext: Boolean = {
    val r = inner.hasNext
    if (!r && !completed) {
      completed = true
      completionFunction
    }
    r
  }
  override def next(): T = inner.next()
  override def close(): Unit = {}