Description Dirk Wiesenthal 2016-01-04 23:55:25 CET

The 3 most expensive things during "univention-appcenter update" are the SSL handshake, decoding bytes to unicode and the MD5 calculations:
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        4    0.191    0.048    0.191    0.048 {built-in method do_handshake}
   151610    0.155    0.000    0.155    0.000 {_codecs.utf_8_decode}
        1    0.151    0.151    0.456    0.456 update.py:306(_read_index_json)

The calculation of the MD5 hash is done very often in 'univention-app update'.
      528    0.011    0.000    0.053    0.000 utils.py:208(get_md5_from_file)

Maybe it also helps to re.compile the regular expressions which are used often (and it doesn't help to compile them every time as done in appcenter.utils.call_process()). E.g. the ones which are passed directly at the App class as AppAttribute. But this shouldn't be a big performance leak:
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
  138/137    0.001    0.000    0.055    0.000 sre_parse.py:663(parse)