# File lib/em/streamer.rb, line 36
    def initialize connection, filename, args = {}
      @connection = connection
      @http_chunks = args[:http_chunks]

      if File.exist?(filename)
        @size = File.size(filename)
        if @size <= MappingThreshold
          stream_without_mapping filename
        else
          stream_with_mapping filename
        end
      else
        fail "file not found"
      end
    end