codekingpro/portable-devtools

1# -*- coding: utf-8 -*-2"""3This module provides an interface to the native time zone data on Windows,4including :py:class:`datetime.tzinfo` implementations.5 6Attempting to import this module on a non-Windows platform will raise an7:py:obj:`ImportError`.8"""9# This code was originally contributed by Jeffrey Harris.10import datetime11import struct12 13from six.moves import winreg14from six import text_type15 16try:17    import ctypes18    from ctypes import wintypes19except ValueError:20    # ValueError is raised on non-Windows systems for some horrible reason.21    raise ImportError("Running tzwin on non-Windows system")22 23from ._common import tzrangebase24 25__all__ = ["tzwin", "tzwinlocal", "tzres"]26 27ONEWEEK = datetime.timedelta(7)28 29TZKEYNAMENT = r"SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones"30TZKEYNAME9X = r"SOFTWARE\Microsoft\Windows\CurrentVersion\Time Zones"31TZLOCALKEYNAME = r"SYSTEM\CurrentControlSet\Control\TimeZoneInformation"32 33 34def _settzkeyname():35    handle = winreg.ConnectRegistry(None, winreg.HKEY_LOCAL_MACHINE)36    try:37        winreg.OpenKey(handle, TZKEYNAMENT).Close()38        TZKEYNAME = TZKEYNAMENT39    except WindowsError:40        TZKEYNAME = TZKEYNAME9X41    handle.Close()42    return TZKEYNAME43 44 45TZKEYNAME = _settzkeyname()46 47 48class tzres(object):49    """50    Class for accessing ``tzres.dll``, which contains timezone name related51    resources.52 53    .. versionadded:: 2.5.054    """55    p_wchar = ctypes.POINTER(wintypes.WCHAR)        # Pointer to a wide char56 57    def __init__(self, tzres_loc='tzres.dll'):58        # Load the user32 DLL so we can load strings from tzres59        user32 = ctypes.WinDLL('user32')60 61        # Specify the LoadStringW function62        user32.LoadStringW.argtypes = (wintypes.HINSTANCE,63                                       wintypes.UINT,64                                       wintypes.LPWSTR,65                                       ctypes.c_int)66 67        self.LoadStringW = user32.LoadStringW68        self._tzres = ctypes.WinDLL(tzres_loc)69        self.tzres_loc = tzres_loc70 71    def load_name(self, offset):72        """73        Load a timezone name from a DLL offset (integer).74 75        >>> from dateutil.tzwin import tzres76        >>> tzr = tzres()77        >>> print(tzr.load_name(112))78        'Eastern Standard Time'79 80        :param offset:81            A positive integer value referring to a string from the tzres dll.82 83        .. note::84 85            Offsets found in the registry are generally of the form86            ``@tzres.dll,-114``. The offset in this case is 114, not -114.87 88        """89        resource = self.p_wchar()90        lpBuffer = ctypes.cast(ctypes.byref(resource), wintypes.LPWSTR)91        nchar = self.LoadStringW(self._tzres._handle, offset, lpBuffer, 0)92        return resource[:nchar]93 94    def name_from_string(self, tzname_str):95        """96        Parse strings as returned from the Windows registry into the time zone97        name as defined in the registry.98 99        >>> from dateutil.tzwin import tzres100        >>> tzr = tzres()101        >>> print(tzr.name_from_string('@tzres.dll,-251'))102        'Dateline Daylight Time'103        >>> print(tzr.name_from_string('Eastern Standard Time'))104        'Eastern Standard Time'105 106        :param tzname_str:107            A timezone name string as returned from a Windows registry key.108 109        :return:110            Returns the localized timezone string from tzres.dll if the string111            is of the form `@tzres.dll,-offset`, else returns the input string.112        """113        if not tzname_str.startswith('@'):114            return tzname_str115 116        name_splt = tzname_str.split(',-')117        try:118            offset = int(name_splt[1])119        except:120            raise ValueError("Malformed timezone string.")121 122        return self.load_name(offset)123 124 125class tzwinbase(tzrangebase):126    """tzinfo class based on win32's timezones available in the registry."""127    def __init__(self):128        raise NotImplementedError('tzwinbase is an abstract base class')129 130    def __eq__(self, other):131        # Compare on all relevant dimensions, including name.132        if not isinstance(other, tzwinbase):133            return NotImplemented134 135        return  (self._std_offset == other._std_offset and136                 self._dst_offset == other._dst_offset and137                 self._stddayofweek == other._stddayofweek and138                 self._dstdayofweek == other._dstdayofweek and139                 self._stdweeknumber == other._stdweeknumber and140                 self._dstweeknumber == other._dstweeknumber and141                 self._stdhour == other._stdhour and142                 self._dsthour == other._dsthour and143                 self._stdminute == other._stdminute and144                 self._dstminute == other._dstminute and145                 self._std_abbr == other._std_abbr and146                 self._dst_abbr == other._dst_abbr)147 148    @staticmethod149    def list():150        """Return a list of all time zones known to the system."""151        with winreg.ConnectRegistry(None, winreg.HKEY_LOCAL_MACHINE) as handle:152            with winreg.OpenKey(handle, TZKEYNAME) as tzkey:153                result = [winreg.EnumKey(tzkey, i)154                          for i in range(winreg.QueryInfoKey(tzkey)[0])]155        return result156 157    def display(self):158        """159        Return the display name of the time zone.160        """161        return self._display162 163    def transitions(self, year):164        """165        For a given year, get the DST on and off transition times, expressed166        always on the standard time side. For zones with no transitions, this167        function returns ``None``.168 169        :param year:170            The year whose transitions you would like to query.171 172        :return:173            Returns a :class:`tuple` of :class:`datetime.datetime` objects,174            ``(dston, dstoff)`` for zones with an annual DST transition, or175            ``None`` for fixed offset zones.176        """177 178        if not self.hasdst:179            return None180 181        dston = picknthweekday(year, self._dstmonth, self._dstdayofweek,182                               self._dsthour, self._dstminute,183                               self._dstweeknumber)184 185        dstoff = picknthweekday(year, self._stdmonth, self._stddayofweek,186                                self._stdhour, self._stdminute,187                                self._stdweeknumber)188 189        # Ambiguous dates default to the STD side190        dstoff -= self._dst_base_offset191 192        return dston, dstoff193 194    def _get_hasdst(self):195        return self._dstmonth != 0196 197    @property198    def _dst_base_offset(self):199        return self._dst_base_offset_200 201 202class tzwin(tzwinbase):203    """204    Time zone object created from the zone info in the Windows registry205 206    These are similar to :py:class:`dateutil.tz.tzrange` objects in that207    the time zone data is provided in the format of a single offset rule208    for either 0 or 2 time zone transitions per year.209 210    :param: name211        The name of a Windows time zone key, e.g. "Eastern Standard Time".212        The full list of keys can be retrieved with :func:`tzwin.list`.213    """214 215    def __init__(self, name):216        self._name = name217 218        with winreg.ConnectRegistry(None, winreg.HKEY_LOCAL_MACHINE) as handle:219            tzkeyname = text_type("{kn}\\{name}").format(kn=TZKEYNAME, name=name)220            with winreg.OpenKey(handle, tzkeyname) as tzkey:221                keydict = valuestodict(tzkey)222 223        self._std_abbr = keydict["Std"]224        self._dst_abbr = keydict["Dlt"]225 226        self._display = keydict["Display"]227 228        # See http://ww_winreg.jsiinc.com/SUBA/tip0300/rh0398.htm229        tup = struct.unpack("=3l16h", keydict["TZI"])230        stdoffset = -tup[0]-tup[1]          # Bias + StandardBias * -1231        dstoffset = stdoffset-tup[2]        # + DaylightBias * -1232        self._std_offset = datetime.timedelta(minutes=stdoffset)233        self._dst_offset = datetime.timedelta(minutes=dstoffset)234 235        # for the meaning see the win32 TIME_ZONE_INFORMATION structure docs236        # http://msdn.microsoft.com/en-us/library/windows/desktop/ms725481(v=vs.85).aspx237        (self._stdmonth,238         self._stddayofweek,   # Sunday = 0239         self._stdweeknumber,  # Last = 5240         self._stdhour,241         self._stdminute) = tup[4:9]242 243        (self._dstmonth,244         self._dstdayofweek,   # Sunday = 0245         self._dstweeknumber,  # Last = 5246         self._dsthour,247         self._dstminute) = tup[12:17]248 249        self._dst_base_offset_ = self._dst_offset - self._std_offset250        self.hasdst = self._get_hasdst()251 252    def __repr__(self):253        return "tzwin(%s)" % repr(self._name)254 255    def __reduce__(self):256        return (self.__class__, (self._name,))257 258 259class tzwinlocal(tzwinbase):260    """261    Class representing the local time zone information in the Windows registry262 263    While :class:`dateutil.tz.tzlocal` makes system calls (via the :mod:`time`264    module) to retrieve time zone information, ``tzwinlocal`` retrieves the265    rules directly from the Windows registry and creates an object like266    :class:`dateutil.tz.tzwin`.267 268    Because Windows does not have an equivalent of :func:`time.tzset`, on269    Windows, :class:`dateutil.tz.tzlocal` instances will always reflect the270    time zone settings *at the time that the process was started*, meaning271    changes to the machine's time zone settings during the run of a program272    on Windows will **not** be reflected by :class:`dateutil.tz.tzlocal`.273    Because ``tzwinlocal`` reads the registry directly, it is unaffected by274    this issue.275    """276    def __init__(self):277        with winreg.ConnectRegistry(None, winreg.HKEY_LOCAL_MACHINE) as handle:278            with winreg.OpenKey(handle, TZLOCALKEYNAME) as tzlocalkey:279                keydict = valuestodict(tzlocalkey)280 281            self._std_abbr = keydict["StandardName"]282            self._dst_abbr = keydict["DaylightName"]283 284            try:285                tzkeyname = text_type('{kn}\\{sn}').format(kn=TZKEYNAME,286                                                          sn=self._std_abbr)287                with winreg.OpenKey(handle, tzkeyname) as tzkey:288                    _keydict = valuestodict(tzkey)289                    self._display = _keydict["Display"]290            except OSError:291                self._display = None292 293        stdoffset = -keydict["Bias"]-keydict["StandardBias"]294        dstoffset = stdoffset-keydict["DaylightBias"]295 296        self._std_offset = datetime.timedelta(minutes=stdoffset)297        self._dst_offset = datetime.timedelta(minutes=dstoffset)298 299        # For reasons unclear, in this particular key, the day of week has been300        # moved to the END of the SYSTEMTIME structure.301        tup = struct.unpack("=8h", keydict["StandardStart"])302 303        (self._stdmonth,304         self._stdweeknumber,  # Last = 5305         self._stdhour,306         self._stdminute) = tup[1:5]307 308        self._stddayofweek = tup[7]309 310        tup = struct.unpack("=8h", keydict["DaylightStart"])311 312        (self._dstmonth,313         self._dstweeknumber,  # Last = 5314         self._dsthour,315         self._dstminute) = tup[1:5]316 317        self._dstdayofweek = tup[7]318 319        self._dst_base_offset_ = self._dst_offset - self._std_offset320        self.hasdst = self._get_hasdst()321 322    def __repr__(self):323        return "tzwinlocal()"324 325    def __str__(self):326        # str will return the standard name, not the daylight name.327        return "tzwinlocal(%s)" % repr(self._std_abbr)328 329    def __reduce__(self):330        return (self.__class__, ())331 332 333def picknthweekday(year, month, dayofweek, hour, minute, whichweek):334    """ dayofweek == 0 means Sunday, whichweek 5 means last instance """335    first = datetime.datetime(year, month, 1, hour, minute)336 337    # This will work if dayofweek is ISO weekday (1-7) or Microsoft-style (0-6),338    # Because 7 % 7 = 0339    weekdayone = first.replace(day=((dayofweek - first.isoweekday()) % 7) + 1)340    wd = weekdayone + ((whichweek - 1) * ONEWEEK)341    if (wd.month != month):342        wd -= ONEWEEK343 344    return wd345 346 347def valuestodict(key):348    """Convert a registry key's values to a dictionary."""349    dout = {}350    size = winreg.QueryInfoKey(key)[1]351    tz_res = None352 353    for i in range(size):354        key_name, value, dtype = winreg.EnumValue(key, i)355        if dtype == winreg.REG_DWORD or dtype == winreg.REG_DWORD_LITTLE_ENDIAN:356            # If it's a DWORD (32-bit integer), it's stored as unsigned - convert357            # that to a proper signed integer358            if value & (1 << 31):359                value = value - (1 << 32)360        elif dtype == winreg.REG_SZ:361            # If it's a reference to the tzres DLL, load the actual string362            if value.startswith('@tzres'):363                tz_res = tz_res or tzres()364                value = tz_res.name_from_string(value)365 366            value = value.rstrip('\x00')    # Remove trailing nulls367 368        dout[key_name] = value369 370    return dout371