A Bloom Filter in Ruby

bloom.rb

require "zlib"

class BloomFilter
  def initialize(size=100, hash_count=3)
    raise(ArgumentError, "negative or zero buffer size") if size <= 0
    raise(ArgumentError, "negative or zero hash count") if hash_count <= 0
    
    @size = size
    @hash_count = hash_count
    @buffer = Array.new(size, false)
  end
  
  def insert(element)
    hash(element).each { |i| @buffer[i] = true}
  end
  
  def maybe_include?(element)
    hash(element).map { |i| @buffer[i] }.inject(:&)
  end
  
  private :hash
  def hash(element)
    hashes = []
    
    1.upto(@hash_count) do |i|
      hashes << Zlib.crc32(element, i)
    end
    
    hashes.map { |h| h % @size }
  end
end

b = BloomFilter.new(50, 5)

b.insert("hello")
puts b.maybe_include?("hello") # => true
puts b.maybe_include?("goodbye") # => false

I realise the hashing is stupid but IDGAF.