diff options
| -rw-r--r-- | Lib/tempfile.py | 35 | ||||
| -rw-r--r-- | Lib/test/test_tempfile.py | 5 |
2 files changed, 25 insertions, 15 deletions
diff --git a/Lib/tempfile.py b/Lib/tempfile.py index 6112208..6146235 100644 --- a/Lib/tempfile.py +++ b/Lib/tempfile.py @@ -133,21 +133,32 @@ def _sanitize_params(prefix, suffix, dir): return prefix, suffix, dir, output_type -def _RandomNameSequence(): - """Generate an endless sequence of unpredictable strings which - can safely be incorporated into file names. Each string is 8 - characters long. Multiple threads and forked processes can - safely use the same instance at the same time.""" +class _RandomNameSequence: + """An instance of _RandomNameSequence generates an endless + sequence of unpredictable strings which can safely be incorporated + into file names. Each string is six characters long. Multiple + threads can safely use the same instance at the same time. + + _RandomNameSequence is an iterator.""" characters = "abcdefghijklmnopqrstuvwxyz0123456789_" - rng_pid = None - while True: + + @property + def rng(self): cur_pid = _os.getpid() - if cur_pid != rng_pid: - choose = _Random().choice - rng_pid = cur_pid - letters = [choose(characters) for dummy in range(8)] - yield ''.join(letters) + if cur_pid != getattr(self, '_rng_pid', None): + self._rng = _Random() + self._rng_pid = cur_pid + return self._rng + + def __iter__(self): + return self + + def __next__(self): + c = self.characters + choose = self.rng.choice + letters = [choose(c) for dummy in range(8)] + return ''.join(letters) def _candidate_tempdir_list(): """Generate a list of candidate temporary directories which diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py index 367e48d..51df1ec 100644 --- a/Lib/test/test_tempfile.py +++ b/Lib/test/test_tempfile.py @@ -1,5 +1,4 @@ # tempfile.py unit tests. -import collections.abc import tempfile import errno import io @@ -291,9 +290,9 @@ class TestGetCandidateNames(BaseTestCase): """Test the internal function _get_candidate_names.""" def test_retval(self): - # _get_candidate_names returns an iterator + # _get_candidate_names returns a _RandomNameSequence object obj = tempfile._get_candidate_names() - self.assertIsInstance(obj, collections.abc.Iterator) + self.assertIsInstance(obj, tempfile._RandomNameSequence) def test_same_thing(self): # _get_candidate_names always returns the same object |