compare_stream

# File lib/fileutils.rb, line 814
  def compare_stream(a, b)
    bsize = fu_stream_blksize(a, b)

    if RUBY_VERSION > "2.4"
      sa = String.new(capacity: bsize)
      sb = String.new(capacity: bsize)
    else
      sa = String.new
      sb = String.new
    end

    begin
      a.read(bsize, sa)
      b.read(bsize, sb)
      return true if sa.empty? && sb.empty?
    end while sa == sb
    false
  end