flare.rb

class Flare
  # limit value size
  MAX_VALUE_SIZE = 10_000_000

  # connections
  @@connection = {
    :writer => nil,
    :reader => nil
  }
  @@flare_saver = nil

  class << self
    # find
    def find(klass, id)
      hashkey = make_hashkey(klass, id)

      setup
      value = @@connection[:writer].get(hashkey)
      value.blank? ? nil : Marshal.load(value)
    end

    # save
    def save(klass, id, value)
      raise "Class is not specified." unless klass
      raise "ID is not specified." unless id
      dumped_value = Marshal.dump(value)
      raise "value exceeds limit size." if dumped_value.size > MAX_VALUE_SIZE

      hashkey = make_hashkey(klass, id)

      setup
      @@connection[:writer].set(hashkey, dumped_value)
    end

    # setup
    def setup
      configure
      connect
    end

    private
    # configuration
    def configure
      unless @@flare_saver
        @@flare_saver = {
          :writer => ["localhost:12121"],
          :reader => ["localhost:12121"]
        }
      end
    end

    # setup connection
    def connect
      @@connection
      unless @@connection[:writer]
        @@connection[:writer] = MemCache.new @@flare_saver[:writer], :namespace => "hogehoge"
      end

      unless @@connection[:reader]
        @@connection[:reader] = MemCache.new @@flare_saver[:reader], :namespace => "hogehoge", :readonly => true
      end
    end

    # make hash-key
    def make_hashkey(klass, id)
      "#{klass}#{Digest::SHA1.hexdigest(id.to_s)}"
    end
  end
end