override def ++()

in algebird-core/src/main/scala/com/twitter/algebird/CountMinSketch.scala [644:659]

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

  override def ++(other: CMS[K]): CMS[K] =
    other match {
      case _: CMSZero[_]       => this
      case other: CMSItem[K]   => this + (other.item, other.totalCount)
      case other: SparseCMS[K] =>
        // This SparseCMS's maxExactCount is used, so ++ is not communitive
        val newTable = Semigroup.plus(exactCountTable, other.exactCountTable)
        if (newTable.size < maxExactCount) {
          // still sparse
          SparseCMS(newTable, totalCount = totalCount + other.totalCount, params = params)
        } else {
          toDense(newTable, params)
        }

      case other: CMSInstance[K] => other ++ this
    }