# File lib/ruote/storage/base.rb, line 313
    def prepare_msg_doc(action, options)

      # merge! is way faster than merge (no object creation probably)

      @counter ||= 0

      t = Time.now.utc
      ts = "#{t.strftime('%Y-%m-%d')}!#{t.to_i}.#{'%06d' % t.usec}"
      _id = "#{$$}!#{Thread.current.object_id}!#{ts}!#{'%03d' % @counter}"

      @counter = (@counter + 1) % 1000
        # some platforms (windows) have shallow usecs, so adding that counter...

      msg = options.merge!('type' => 'msgs', '_id' => _id, 'action' => action)

      msg.delete('_rev')
        # in case of message replay

      msg
    end