counter.rb

class Counter
  # class method:
  def self.increment(bucket, key, by=1)
    # do something here, *without* fetching
  end

  attr_accessor :bucket
  attr_accessor :key

  def initialize(bucket, key)
    @bucket = bucket
    @key = key
    @ops = []
    @value = request_value
  end

  attr_reader :value

  def increment(by)
    @ops.push([:increment, by])
    value += by
  end

  def send_operations!
    encode_and_send(@ops)
    @ops = []
    @value = request_value
  end

  def recache_value
    @value = request_value
    apply_unsent_ops_to_value
  end

  def dirty?
    @ops.present?
  end

  def request_value
    # lol todo
  end

  def apply_unsent_ops_to_value
    # lol todo
  end

  def encode_and_send
    # lol tod
  end
end

example.rb

# counter
counter = Counter.new("test", "test")
counter.value # => 5

# do some stuff client side
counter.increment(5)
counter.value # => 10
counter.dirty? # => true

# actually send the changes to the client side.
counter.send_operations!
counter.value # => 10
counter.dirty? # => false

# But without a fetch:
Counter.increment("test", "test")