# -*- coding: utf-8 -*-
"""UUID version 1 time implementation."""
import decimal
from dfdatetime import definitions
from dfdatetime import factory
from dfdatetime import interface
[docs]
class UUIDTimeEpoch(interface.DateTimeEpoch):
"""UUID version 1 time epoch."""
[docs]
def __init__(self):
"""Initializes an UUID version 1 time epoch."""
super(UUIDTimeEpoch, self).__init__(1582, 10, 15)
[docs]
class UUIDTime(interface.DateTimeValues):
"""UUID version 1 timestamp.
The UUID version 1 timestamp is an unsigned 60-bit value that contains
the number of 100th nano seconds intervals since 1582-10-15 00:00:00.
Also see:
https://en.wikipedia.org/wiki/Universally_unique_identifier
Attributes:
is_local_time (bool): True if the date and time value is in local time.
"""
_EPOCH = UUIDTimeEpoch()
# The difference between October 15, 1582 and January 1, 1970 in seconds.
_UUID_TO_POSIX_BASE = 12219292800
[docs]
def __init__(self, precision=None, time_zone_offset=None, timestamp=None):
"""Initializes an UUID version 1 timestamp.
Args:
precision (Optional[str]): precision of the date and time value, which
should be one of the PRECISION_VALUES in definitions.
time_zone_offset (Optional[int]): time zone offset in number of minutes
from UTC or None if not set.
timestamp (Optional[int]): UUID version 1 timestamp.
Raises:
ValueError: if the UUID version 1 timestamp is invalid.
"""
if timestamp and (timestamp < 0 or timestamp > self._UINT60_MAX):
raise ValueError('Invalid UUID version 1 timestamp.')
super(UUIDTime, self).__init__(
precision=precision or definitions.PRECISION_100_NANOSECONDS,
time_zone_offset=time_zone_offset)
self._timestamp = timestamp
@property
def timestamp(self):
"""int: UUID timestamp or None if not set."""
return self._timestamp
def _GetNormalizedTimestamp(self):
"""Retrieves the normalized timestamp.
Returns:
decimal.Decimal: normalized timestamp, which contains the number of
seconds since January 1, 1970 00:00:00 and a fraction of second
used for increased precision, or None if the normalized timestamp
cannot be determined.
"""
if self._normalized_timestamp is None:
if (self._timestamp is not None and self._timestamp >= 0 and
self._timestamp <= self._UINT60_MAX):
self._normalized_timestamp = (
decimal.Decimal(self._timestamp) / self._100_NANOSECONDS_PER_SECOND)
self._normalized_timestamp -= self._UUID_TO_POSIX_BASE
if self._time_zone_offset:
self._normalized_timestamp -= self._time_zone_offset * 60
return self._normalized_timestamp
[docs]
def CopyFromDateTimeString(self, time_string):
"""Copies an UUID timestamp from a date and time string.
Args:
time_string (str): date and time value formatted as:
YYYY-MM-DD hh:mm:ss.######[+-]##:##
Where # are numeric digits ranging from 0 to 9 and the seconds
fraction can be either 3, 6 or 9 digits. The time of day, seconds
fraction and time zone offset are optional. The default time zone
is UTC.
Raises:
ValueError: if the time string is invalid or not supported.
"""
date_time_values = self._CopyDateTimeFromString(time_string)
year = date_time_values.get('year', 0)
month = date_time_values.get('month', 0)
day_of_month = date_time_values.get('day_of_month', 0)
hours = date_time_values.get('hours', 0)
minutes = date_time_values.get('minutes', 0)
seconds = date_time_values.get('seconds', 0)
nanoseconds = date_time_values.get('nanoseconds', 0)
time_zone_offset = date_time_values.get('time_zone_offset', None)
if year < 1582:
raise ValueError('Year value not supported.')
nanoseconds, _ = divmod(nanoseconds, 100)
timestamp = self._GetNumberOfSecondsFromElements(
year, month, day_of_month, hours, minutes, seconds)
timestamp += self._UUID_TO_POSIX_BASE
timestamp *= self._100_NANOSECONDS_PER_SECOND
timestamp += nanoseconds
self._normalized_timestamp = None
self._timestamp = timestamp
self._time_zone_offset = time_zone_offset
[docs]
def CopyToDateTimeString(self):
"""Copies the UUID timestamp to a date and time string.
Returns:
str: date and time value formatted as: "YYYY-MM-DD hh:mm:ss.#######" or
None if the timestamp is missing or invalid.
"""
if (self._timestamp is None or self._timestamp < 0 or
self._timestamp > self._UINT60_MAX):
return None
timestamp, fraction_of_second = divmod(
self._timestamp, self._100_NANOSECONDS_PER_SECOND)
number_of_days, hours, minutes, seconds = self._GetTimeValues(timestamp)
year, month, day_of_month = self._GetDateValuesWithEpoch(
number_of_days, self._EPOCH)
return (f'{year:04d}-{month:02d}-{day_of_month:02d} '
f'{hours:02d}:{minutes:02d}:{seconds:02d}.{fraction_of_second:07d}')
factory.Factory.RegisterDateTimeValues(UUIDTime)