From c7217d7c2210008ba06e9bcb2a14439a451eef71 Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Thu, 3 Dec 2015 22:21:07 +0200 Subject: [PATCH] Issue #6478: _strptime's regexp cache now is reset after changing timezone with time.tzset(). --- Lib/_strptime.py | 21 +++++++++++++------- Lib/test/test_strptime.py | 40 ++++++++++++++++++++++++++++++++------- Misc/NEWS | 3 +++ 3 files changed, 50 insertions(+), 14 deletions(-) diff --git a/Lib/_strptime.py b/Lib/_strptime.py index f76fff14fce..6d648568b6e 100644 --- a/Lib/_strptime.py +++ b/Lib/_strptime.py @@ -77,6 +77,8 @@ class LocaleTime(object): self.__calc_date_time() if _getlang() != self.lang: raise ValueError("locale changed during initialization") + if time.tzname != self.tzname or time.daylight != self.daylight: + raise ValueError("timezone changed during initialization") def __pad(self, seq, front): # Add '' to seq to either the front (is True), else the back. @@ -161,15 +163,17 @@ class LocaleTime(object): def __calc_timezone(self): # Set self.timezone by using time.tzname. - # Do not worry about possibility of time.tzname[0] == timetzname[1] - # and time.daylight; handle that in strptime . + # Do not worry about possibility of time.tzname[0] == time.tzname[1] + # and time.daylight; handle that in strptime. try: time.tzset() except AttributeError: pass - no_saving = frozenset(["utc", "gmt", time.tzname[0].lower()]) - if time.daylight: - has_saving = frozenset([time.tzname[1].lower()]) + self.tzname = time.tzname + self.daylight = time.daylight + no_saving = frozenset(["utc", "gmt", self.tzname[0].lower()]) + if self.daylight: + has_saving = frozenset([self.tzname[1].lower()]) else: has_saving = frozenset() self.timezone = (no_saving, has_saving) @@ -308,12 +312,15 @@ def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"): global _TimeRE_cache, _regex_cache with _cache_lock: - if _getlang() != _TimeRE_cache.locale_time.lang: + locale_time = _TimeRE_cache.locale_time + if (_getlang() != locale_time.lang or + time.tzname != locale_time.tzname or + time.daylight != locale_time.daylight): _TimeRE_cache = TimeRE() _regex_cache.clear() + locale_time = _TimeRE_cache.locale_time if len(_regex_cache) > _CACHE_MAX_SIZE: _regex_cache.clear() - locale_time = _TimeRE_cache.locale_time format_regex = _regex_cache.get(format) if not format_regex: try: diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py index 2a6f3f86e6a..c1dd1954789 100644 --- a/Lib/test/test_strptime.py +++ b/Lib/test/test_strptime.py @@ -4,6 +4,7 @@ import unittest import time import locale import re +import os import sys from test import support from datetime import date as datetime_date @@ -324,9 +325,10 @@ class StrptimeTests(unittest.TestCase): tz_name = time.tzname[0] if tz_name.upper() in ("UTC", "GMT"): self.skipTest('need non-UTC/GMT timezone') - try: - original_tzname = time.tzname - original_daylight = time.daylight + + with support.swap_attr(time, 'tzname', (tz_name, tz_name)), \ + support.swap_attr(time, 'daylight', 1), \ + support.swap_attr(time, 'tzset', lambda: None): time.tzname = (tz_name, tz_name) time.daylight = 1 tz_value = _strptime._strptime_time(tz_name, "%Z")[8] @@ -334,9 +336,6 @@ class StrptimeTests(unittest.TestCase): "%s lead to a timezone value of %s instead of -1 when " "time.daylight set to %s and passing in %s" % (time.tzname, tz_value, time.daylight, tz_name)) - finally: - time.tzname = original_tzname - time.daylight = original_daylight def test_date_time(self): # Test %c directive @@ -548,7 +547,7 @@ class CacheTests(unittest.TestCase): _strptime._strptime_time("10", "%d") self.assertIsNot(locale_time_id, _strptime._TimeRE_cache.locale_time) - def test_TimeRE_recreation(self): + def test_TimeRE_recreation_locale(self): # The TimeRE instance should be recreated upon changing the locale. locale_info = locale.getlocale(locale.LC_TIME) try: @@ -577,6 +576,33 @@ class CacheTests(unittest.TestCase): finally: locale.setlocale(locale.LC_TIME, locale_info) + @support.run_with_tz('STD-1DST') + def test_TimeRE_recreation_timezone(self): + # The TimeRE instance should be recreated upon changing the timezone. + oldtzname = time.tzname + tm = _strptime._strptime_time(time.tzname[0], '%Z') + self.assertEqual(tm.tm_isdst, 0) + tm = _strptime._strptime_time(time.tzname[1], '%Z') + self.assertEqual(tm.tm_isdst, 1) + # Get id of current cache object. + first_time_re = _strptime._TimeRE_cache + # Change the timezone and force a recreation of the cache. + os.environ['TZ'] = 'EST+05EDT,M3.2.0,M11.1.0' + time.tzset() + tm = _strptime._strptime_time(time.tzname[0], '%Z') + self.assertEqual(tm.tm_isdst, 0) + tm = _strptime._strptime_time(time.tzname[1], '%Z') + self.assertEqual(tm.tm_isdst, 1) + # Get the new cache object's id. + second_time_re = _strptime._TimeRE_cache + # They should not be equal. + self.assertIsNot(first_time_re, second_time_re) + # Make sure old names no longer accepted. + with self.assertRaises(ValueError): + _strptime._strptime_time(oldtzname[0], '%Z') + with self.assertRaises(ValueError): + _strptime._strptime_time(oldtzname[1], '%Z') + def test_main(): support.run_unittest( diff --git a/Misc/NEWS b/Misc/NEWS index 076b0b5ab28..76296000b45 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -115,6 +115,9 @@ Core and Builtins Library ------- +- Issue #6478: _strptime's regexp cache now is reset after changing timezone + with time.tzset(). + - Issue #25177: Fixed problem with the mean of very small and very large numbers. As a side effect, statistics.mean and statistics.variance should be significantly faster.