Object Oriented Circular Buffer

circular_buffer.rb

class CircularBuffer
  class BufferEmptyException < IOError; end
  class BufferFullException < IOError; end
  attr_reader :data

  def initialize(size)
    @data = Array.new(size)
    @reader = BufferReader.new
    @writer = BufferWriter.new
  end

  def read
    raise BufferEmptyException if buffer_empty?
    @reader.read(data)
  end

  def write(element)
    return unless element
    raise BufferFullException if buffer_full?
    @writer.reset if @writer.index == data.size
    @writer.write(data, element)
  end

  def write!(element)
    return unless element
    @reader.increment_index if buffer_full?
    @writer.write(data, element)
  end

  def clear
    data.fill(nil)
  end

  private

  def buffer_empty?
    data.compact.empty?
  end

  def buffer_full?
    data.none?(&:nil?)
  end
end

class BufferWriter
  attr_reader :index

  def initialize
    reset
  end

  def write(data, element)
    @index = 0 if @index == data.size
    data[@index] = element
    @index += 1
  end

  def reset
    @index = 0
  end
end

class BufferReader
  def initialize
    @index = 0
  end

  def read(data)
    @index = 0 if @index == data.size
    value = data[@index]
    data[@index] = nil
    increment_index
    value
  end

  def increment_index
    @index += 1
  end
end