Method: Net::DNS::MDNS::Responder#cacher_loop

Defined in:

lib/net/dns/mdns.rb

#cacher_loop ⇒ Object

# File 'lib/net/dns/mdns.rb', line 636

def cacher_loop
  delay = 0

  loop do

    if delay > 0
      sleep(delay)
    else
      sleep
    end

    @mutex.synchronize do
      debug( "sweep begin" )

      @waketime = nil

      msg = Message.new(0)
      msg.rd = 0
      msg.qr = 0
      msg.aa = 0

      now = Time.now.to_i

      # the earliest question or answer we need to wake for
      wakefor = nil

      # TODO - A delete expired, that yields every answer before
      # deleting it (so I can log it).
      # TODO - A #each_answer?
      @cache.cached.each do |name,rtypes|
        rtypes.each do |rtype, answers|
          # Delete expired answers.
          answers.delete_if do |an|
            if an.expired?
              debug( "-- a #{an}" )
              true
            end
          end
          # Requery answers that need refreshing, if there is a query that wants it.
          # Remember the earliest one we need to wake for.
          answers.each do |an|
            if an.refresh
              unless @queries.detect { |q| q.subscribes_to? an }
                debug( "no refresh of: a #{an}" )
                next
              end
              if now >= an.refresh
                an.retries += 1
                msg.add_question(name, an.data.class)
              end
              # TODO: cacher_loop exited with comparison of Bignum with nil failed, v2mdns.rb:478:in `<'
              begin
              if !wakefor || an.refresh < wakefor.refresh
                wakefor = an
              end
              rescue
                error( "an #{an.inspect}" )
                error( "wakefor #{wakefor.inspect}" )
                raise
              end
            end
          end
        end
      end

      @cache.asked.each do |name,rtypes|
        # Delete questions no query subscribes to, and that don't need refreshing.
        rtypes.delete_if do |rtype, qu|
          if !qu.refresh || !@queries.detect { |q| q.subscribes_to? qu }
            debug( "no refresh of: q #{qu}" )
            true
          end
        end
        # Requery questions that need refreshing.
        # Remember the earliest one we need to wake for.
        rtypes.each do |rtype, qu|
          if now >= qu.refresh
            msg.add_question(name, rtype)
          end
          if !wakefor || qu.refresh < wakefor.refresh
            wakefor = qu
          end
        end
      end

      msg.question.uniq!

      msg.each_question { |n,r| debug( "-> q #{n} #{DNS.rrname(r)}" ) }

      send(msg) if msg.question.first

      @waketime = wakefor.refresh if wakefor

      if @waketime
        delay = @waketime - Time.now.to_i
        delay = 1 if delay < 1

        debug( "refresh in #{delay} sec for #{wakefor}" )
      else
        delay = 0
      end

      debug( "sweep end" )
    end
  end # end loop
end