module FSSM::Backends
  class Polling
    def initialize(options={})
      @handlers  = []
      @latency   = options[:latency]   || 1
    end

    def add_path(path, preload=true)
      handler = FSSM::State.new(path)
      handler.refresh(path.to_pathname, true) if preload
      @handlers << handler
    end

    def run
      begin
        loop do
          start = Time.now.to_f
          @handlers.each {|handler| handler.refresh}
          nap_time = @latency - (Time.now.to_f - start)
          sleep nap_time if nap_time > 0
        end
      rescue Interrupt
      end
    end
  end
end