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author | Serhiy Storchaka <storchaka@gmail.com> | 2017-04-11 22:45:59 +0300 |
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committer | GitHub <noreply@github.com> | 2017-04-11 22:45:59 +0300 |
commit | f50354adaaafebe95ad09d09b825804a686ea843 (patch) | |
tree | 0dc403f1d0b0557927df7857c4c666235c4a3321 /Lib/tempfile.py | |
parent | e8a6bb4f3936123f3eca0b6cea05e2875a2722bc (diff) | |
download | cpython-git-f50354adaaafebe95ad09d09b825804a686ea843.tar.gz |
Reimplement tempfile._RandomNameSequence using a generator function. (#1075)
Diffstat (limited to 'Lib/tempfile.py')
-rw-r--r-- | Lib/tempfile.py | 35 |
1 files changed, 12 insertions, 23 deletions
diff --git a/Lib/tempfile.py b/Lib/tempfile.py index 61462357c7..6112208382 100644 --- a/Lib/tempfile.py +++ b/Lib/tempfile.py @@ -133,32 +133,21 @@ def _sanitize_params(prefix, suffix, dir): return prefix, suffix, dir, output_type -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.""" +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.""" characters = "abcdefghijklmnopqrstuvwxyz0123456789_" - - @property - def rng(self): + rng_pid = None + while True: cur_pid = _os.getpid() - 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) + if cur_pid != rng_pid: + choose = _Random().choice + rng_pid = cur_pid + letters = [choose(characters) for dummy in range(8)] + yield ''.join(letters) def _candidate_tempdir_list(): """Generate a list of candidate temporary directories which |