def build()

in algebird-core/src/main/scala/com/twitter/algebird/TopKMonoid.scala [55:78]

• 22 lines of code
• 6 McCabe index (conditional complexity)

  def build(t: T): TopK[T] = TopK(1, List(t), Some(t))
  def build(ts: Iterable[T]): TopK[T] = ts.foldLeft(zero)((acc, t) => plus(acc, build(t)))

  override def plus(left: TopK[T], right: TopK[T]): TopK[T] = {
    val (bigger, smaller) =
      if (left.size >= right.size) (left, right) else (right, left)
    if (smaller.size == 0) {
      bigger
    } else if (bigger.size == k) {
      // See if we can just return the bigger:
      val biggerWins =
        for {
          biggest <- bigger.max
          smallest <- smaller.items.headOption
        } yield ord.lteq(biggest, smallest)
      if (biggerWins.getOrElse(true)) { // smaller is small, or empty
        bigger
      } else {
        merge(bigger, smaller)
      }
    } else {
      merge(bigger, smaller)
    }
  }