"""Apple File System (APFS) time implementation."""
import decimal
from dfdatetime import definitions
from dfdatetime import factory
from dfdatetime import posix_time
[docs]
class APFSTime(posix_time.PosixTimeInNanoseconds):
"""Apple File System (APFS) timestamp.
The APFS timestamp is a signed 64-bit integer that contains the number of
nanoseconds since 1970-01-01 00:00:00.
Attributes:
is_local_time (bool): True if the date and time value is in local time.
"""
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 >= self._INT64_MIN
and self._timestamp <= self._INT64_MAX
):
self._normalized_timestamp = (
decimal.Decimal(self._timestamp)
/ definitions.NANOSECONDS_PER_SECOND
)
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 APFS 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 date and time value is not supported.
"""
super().CopyFromDateTimeString(time_string)
if (
self._timestamp is None
or self._timestamp < self._INT64_MIN
or self._timestamp > self._INT64_MAX
):
raise ValueError("Date time value not supported.")
[docs]
def CopyToDateTimeString(self):
"""Copies the APFS 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 < self._INT64_MIN
or self._timestamp > self._INT64_MAX
):
return None
return super().CopyToDateTimeString()
factory.Factory.RegisterDateTimeValues(APFSTime)