# File lib/innodb/page/index_compressed.rb, line 30
  def free_space
    free_space_start = size - size_fil_trailer - directory_space -
      (uncompressed_columns_size * (page_header[:n_heap] - 2))
    puts "Free space start == %04x" % [offset * size + free_space_start]
    c = cursor(free_space_start).backward
    zero_bytes = 0
    while (b = c.get_uint8) == 0
      zero_bytes += 1
    end
    zero_bytes
    #page_header[:garbage] +
    #  (size - size_fil_trailer - directory_space - page_header[:heap_top])
  end