class Rack::Cache::MetaStore::MemCached

def initialize(server="localhost:11211", options={})
  options[:prefix_key] ||= options.delete(:namespace) if options.key?(:namespace)
  @cache =
    if server.respond_to?(:stats)
      server
    else
      require 'memcached'
      Memcached.new(server, options)
    end
end

def purge(key)
  key = hexdigest(key)
  cache.delete(key)
  nil
rescue Memcached::NotFound
  nil
end

def read(key)
  key = hexdigest(key)
  cache.get(key)
rescue Memcached::NotFound
  []
end

def write(key, entries, ttl = 0)
  key = hexdigest(key)
  cache.set(key, entries, ttl)
end