atomic_sequence.rb

# Usage
# sequence = AtomicSequence["cats"]
# sequence.current # => 0
# sequence.next # => 1
# sequence.next # => 2
# sequence.current # => 2
# sequence.reset!
# sequence.current # => 0
# sequence.next # => 1

class AtomicSequence < Struct.new(:key)
  Store = REDIS

  def next
    store :incr
  end

  def current
    store(:get).to_i
  end

  def reset!
    store :del
  end

  def self.[](name)
    self.new(name)
  end

  private

  def store(method)
    Store.send(method, key)
  end
end