gistfile1.rb

module SelfRestraint
  class UnableToLock < StandardError; end
    
  def lock(redis, base_key, n)
    if key = lock_obtain
      begin
        yield
      ensure
        redis.del key
      end
    else
      raise UnableToLock, "Unable to obtain lock"
    end
  end
  
  # generate a set of potential lock keys
  def lock_keys(base_key, n)
    n.map { |n| "#{base_key}:#{n}" }
  end
  
  # attempt to obtain a lock at the specific key
  def lock_obtain(redis, key)
    
  end
end