jenkins_one_at_a_time.rb

module ConsistentHashing
  module JenkinsOneAtATime
    extend self
  
    def hash_to_unit_circle(key)
      hash(key)/0xffffffff.to_f
    end
  
    def hash(key)
      hash = 0
      key.each_byte do |byte|
        hash += byte
        hash += (hash << 10)
        hash &= 0xffffffff
        hash ^= (hash >> 6)
      end
    
      hash += (hash << 3)
      hash &= 0xffffffff
      hash ^= (hash >> 11)
      hash += (hash << 15)
      hash &= 0xffffffff
    end
  end
end