Avoid reading whole file

[GreyCat]

Code generated by KS does a fairly good job at not reading the whole file in memory and even doing stuff lazily where possible, but HexViewer component of ksv currently works with a byte array buffer, which is always filled up like that:

  def hv_update_io
    io = @cur_node.io
    if io != @cur_io
      @cur_io = io
      io.seek(0)
      buf = io.read_bytes_full
      @hv.buf = buf
    end
  end

So, effectively it means that huge files would be read fully into memory before doing any visualizations at all. Partially, it depends on kaitai-io/kaitai_struct#44, but even without that probably we could do a IO-based instead of preread byte array based HexViewer.

[honeyspoon]

any update on this?
don't know enough about ruby of the project to implement this but it seems like a great feature