sharkint

1看 int 列 看出存储是列存储格式

class IntColumnBuilder extends ColumnBuilder[Int] {

  private var _stats: ColumnStats.IntColumnStats = null
  private var _arr: IntArrayList = null


  override def initialize(initialSize: Int) {
    _arr = new IntArrayList(initialSize)
    _stats = new ColumnStats.IntColumnStats
    super.initialize(initialSize)
  }


  override def append(o: Object, oi: ObjectInspector) {
    if (o == null) {
      appendNull()
    } else {
      val v = oi.asInstanceOf[IntObjectInspector].get(o)
      append(v)
    }
  }


  override def append(v: Int) {
    _arr.add(v)
    _stats.append(v)
  }

  override def appendNull() {

    _nullBitmap.set(_arr.size)
    _arr.add(0)
    _stats.appendNull()
  }


  override def stats = _stats


  override def build: ByteBuffer = {

    val buf = ByteBuffer.allocate(

/

      _arr.size * 4 + ColumnIterator.COLUMN_TYPE_LENGTH + sizeOfNullBitmap)
    buf.order(ByteOrder.nativeOrder())
    buf.putLong(ColumnIterator.INT)

//nullbitmap进行初始化

    writeNullBitmap(buf)


    var i = 0
    while (i < _arr.size) {
      buf.putInt(_arr.get(i))
      i += 1
    }
    buf.rewind()
    buf
  }

}

sealed trait ColumnStats[@specialized(Boolean, Byte, Short, Int, Long, Float, Double) T]

  extends Serializable {


  var _nullCount = 0


  def append(v: T)


  protected def _min: T
  protected def _max: T


  def appendNull() { _nullCount += 1 }


  def nullCount: Int = _nullCount
  def min: T = _min
  def max: T = _max


  override def toString = "[" + min + ", " + max + "]"
}