# -*- coding: utf-8 -*-
"""Fake timestamp implementation."""
import decimal
import time
from dfdatetime import definitions
from dfdatetime import interface
from dfdatetime import posix_time
[docs]
class FakeTime(interface.DateTimeValues):
"""Fake timestamp.
The fake timestamp is intended for testing purposes. On initialization
it contains the current time in UTC in microsecond precision.
Attributes:
is_local_time (bool): True if the date and time value is in local time.
"""
_EPOCH = posix_time.PosixTimeEpoch()
[docs]
def __init__(self, precision=None, time_zone_offset=None):
"""Initializes a fake 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.
"""
# Note that time.time() and divmod return floating point values.
timestamp, fraction_of_second = divmod(time.time(), 1)
super(FakeTime, self).__init__(
precision=precision or definitions.PRECISION_1_MICROSECOND,
time_zone_offset=time_zone_offset)
self._microseconds = int(
fraction_of_second * definitions.MICROSECONDS_PER_SECOND)
self._number_of_seconds = int(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._number_of_seconds is not None:
self._normalized_timestamp = (
decimal.Decimal(self._microseconds) /
definitions.MICROSECONDS_PER_SECOND)
self._normalized_timestamp += decimal.Decimal(self._number_of_seconds)
if self._time_zone_offset:
self._normalized_timestamp -= self._time_zone_offset * 60
return self._normalized_timestamp
[docs]
def CopyFromDateTimeString(self, time_string):
"""Copies a fake 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.
"""
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', None)
time_zone_offset = date_time_values.get('time_zone_offset', None)
self._normalized_timestamp = None
self._number_of_seconds = self._GetNumberOfSecondsFromElements(
year, month, day_of_month, hours, minutes, seconds)
if nanoseconds is None:
self._microseconds = None
else:
self._microseconds, _ = divmod(nanoseconds, 1000)
self._time_zone_offset = time_zone_offset
[docs]
def CopyToDateTimeString(self):
"""Copies the fake timestamp to a date and time string.
Returns:
str: date and time value formatted as: "YYYY-MM-DD hh:mm:ss" or
"YYYY-MM-DD hh:mm:ss.######" or None if the number of seconds
is missing.
"""
if self._number_of_seconds is None:
return None
number_of_days, hours, minutes, seconds = self._GetTimeValues(
self._number_of_seconds)
year, month, day_of_month = self._GetDateValuesWithEpoch(
number_of_days, self._EPOCH)
date_time_string = (
f'{year:04d}-{month:02d}-{day_of_month:02d} '
f'{hours:02d}:{minutes:02d}:{seconds:02d}')
if self._microseconds is not None:
date_time_string = '.'.join([
date_time_string, f'{self._microseconds:06d}'])
return date_time_string