Seberius/cache_lib

module CacheLib
  module FIFO
    class Cache < Basic::Cache
      def initialize(*args)
        limit, _ = args

        fail ArgumentError, "Cache Limit must be 1 or greater: #{limit}" unless
            limit && (limit.is_a? Numeric) && limit > 0

        @limit = limit
        @ttl = nil

        @cache = Util::ExtHash.new
      end

      def limit=(args)
        limit, _ = args

        limit ||= @limit

        fail ArgumentError, "Cache Limit must be 1 or greater: #{limit}" unless
            limit && (limit.is_a? Numeric) && limit > 0

        @limit = limit

        resize
      end

      protected

      def resize
        @cache.pop_tail while @cache.size > @limit
      end

      def miss(key, value)
        @cache[key] = value

        @cache.pop_tail if @cache.size > @limit

        value
      end
    end
  end
end