def maybeContains()

in algebird-core/src/main/scala/com/twitter/algebird/BloomFilter.scala [382:407]

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

  def maybeContains(item: A): Boolean

  // Estimates the cardinality of the set of elements that have been
  // inserted into the Bloom Filter.
  def size: Approximate[Long]

  def toBitSet: BitSet

  /**
   * Compute the Hamming distance between the two Bloom filters `a` and `b`. The distance is defined as the
   * number of bits that need to change to in order to transform one filter into the other.
   */
  def hammingDistance(that: BF[A]): Int =
    (this, that) match {
      // Comparing with empty filter should give number
      // of bits in other set
      case (_: BFZero[A], _: BFZero[A]) => 0
      case (_: BFZero[A], y: BF[A])     => y.numBits
      case (x: BF[A], _: BFZero[A])     => x.numBits

      // Special case for Sparse vs. Sparse
      case (x: BFSparse[A], y: BFSparse[A]) => x.bits.xorCardinality(y.bits)

      // Otherwise compare as bit sets
      case (_, _) => (this.toBitSet ^ that.toBitSet).size
    }