CGI::Session::FileStore#restore

# File tmp/rubies/ruby-3.2.0/lib/cgi/session.rb, line 424
def restore
  unless @hash
    @hash = {}
    begin
      lockf = File.open(@path+".lock", "r")
      lockf.flock File::LOCK_SH
      f = File.open(@path, 'r')
      for line in f
        line.chomp!
        k, v = line.split('=',2)
        @hash[CGI.unescape(k)] = Marshal.restore(CGI.unescape(v))
      end
    ensure
      f&.close
      lockf&.close
    end
  end
  @hash
end