ringbuffer.rb

class RingBuffer < Array
  attr_reader :max_size
 
  def initialize(max_size, enum = nil)
    @max_size = max_size
    enum.each { |e| self << e } if enum
  end
 
  def <<(el)
    if @max_size && self.size >= @max_size
      self.shift
    end
    super
  end
 
  alias :push :<<
end