# File lib/em/streamer.rb, line 51
51:     def initialize connection, filename, args = {}
52:       @connection = connection
53:       @http_chunks = args[:http_chunks]
54: 
55:       if File.exist?(filename)
56:         @size = File.size?(filename)
57:         if @size <= MappingThreshold
58:           stream_without_mapping filename
59:         else
60:           stream_with_mapping filename
61:         end
62:       else
63:         fail "file not found"
64:       end
65:     end