bazarr/libs/tzlocal/win32.py

105 lines
3.2 KiB
Python

try:
import _winreg as winreg
except ImportError:
import winreg
import pytz
from tzlocal.windows_tz import win_tz
from tzlocal import utils
_cache_tz = None
def valuestodict(key):
"""Convert a registry key's values to a dictionary."""
dict = {}
size = winreg.QueryInfoKey(key)[1]
for i in range(size):
data = winreg.EnumValue(key, i)
dict[data[0]] = data[1]
return dict
def get_localzone_name():
# Windows is special. It has unique time zone names (in several
# meanings of the word) available, but unfortunately, they can be
# translated to the language of the operating system, so we need to
# do a backwards lookup, by going through all time zones and see which
# one matches.
handle = winreg.ConnectRegistry(None, winreg.HKEY_LOCAL_MACHINE)
TZLOCALKEYNAME = r"SYSTEM\CurrentControlSet\Control\TimeZoneInformation"
localtz = winreg.OpenKey(handle, TZLOCALKEYNAME)
keyvalues = valuestodict(localtz)
localtz.Close()
if 'TimeZoneKeyName' in keyvalues:
# Windows 7 (and Vista?)
# For some reason this returns a string with loads of NUL bytes at
# least on some systems. I don't know if this is a bug somewhere, I
# just work around it.
tzkeyname = keyvalues['TimeZoneKeyName'].split('\x00', 1)[0]
else:
# Windows 2000 or XP
# This is the localized name:
tzwin = keyvalues['StandardName']
# Open the list of timezones to look up the real name:
TZKEYNAME = r"SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones"
tzkey = winreg.OpenKey(handle, TZKEYNAME)
# Now, match this value to Time Zone information
tzkeyname = None
for i in range(winreg.QueryInfoKey(tzkey)[0]):
subkey = winreg.EnumKey(tzkey, i)
sub = winreg.OpenKey(tzkey, subkey)
data = valuestodict(sub)
sub.Close()
try:
if data['Std'] == tzwin:
tzkeyname = subkey
break
except KeyError:
# This timezone didn't have proper configuration.
# Ignore it.
pass
tzkey.Close()
handle.Close()
if tzkeyname is None:
raise LookupError('Can not find Windows timezone configuration')
timezone = win_tz.get(tzkeyname)
if timezone is None:
# Nope, that didn't work. Try adding "Standard Time",
# it seems to work a lot of times:
timezone = win_tz.get(tzkeyname + " Standard Time")
# Return what we have.
if timezone is None:
raise pytz.UnknownTimeZoneError('Can not find timezone ' + tzkeyname)
return timezone
def get_localzone():
"""Returns the zoneinfo-based tzinfo object that matches the Windows-configured timezone."""
global _cache_tz
if _cache_tz is None:
_cache_tz = pytz.timezone(get_localzone_name())
utils.assert_tz_offset(_cache_tz)
return _cache_tz
def reload_localzone():
"""Reload the cached localzone. You need to call this if the timezone has changed."""
global _cache_tz
_cache_tz = pytz.timezone(get_localzone_name())
utils.assert_tz_offset(_cache_tz)
return _cache_tz