Cached Address Proxy

cachable_address.rb

require "dalli"
require "yaml"

module MTDataStone
  class CachableAddresses < Addresses
    
    DALLI_HOST = "localhost:11211"
    DALLI_OPTIONS = {}
    EXPIRY_PERIOD = 60.days
    
    def get_autocomplete_suggestions(fleet, street)
      cached?("#{fleet}:#{street}") do 
        super(fleet, street)
      end
    end
    
    def cached?(key, &block)
      cached = fetch_cached(key)
      unless cached
        cached = yield
        set_cached(key, cached)
      end
      cached
    end
    
    def cache
      @cache ||= Dalli::Client.new(DALLI_HOST, DALLI_OPTIONS)
    end
    
    def fetch_cached(key)
      data = cache.get(key)
      return YAML.load(data) if data
    end
    
    def set_cached(key, value)
      cache.set(key, cached.to_yaml, EXPIRY_PERIOD)
    end 
    
  end
end