#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""Timestamp utilities.
For internal use only; no backwards-compatibility guarantees.
"""
from __future__ import absolute_import
from __future__ import division
import datetime
import re
import pytz
from six import integer_types
class Timestamp(object):
"""Represents a Unix second timestamp with microsecond granularity.
Can be treated in common timestamp arithmetic operations as a numeric type.
Internally stores a time interval as an int of microseconds. This strategy
is necessary since floating point values lose precision when storing values,
especially after arithmetic operations (for example, 10000000 % 0.1 evaluates
to 0.0999999994448885).
"""
def __init__(self, seconds=0, micros=0):
if not isinstance(seconds, integer_types + (float,)):
raise TypeError('Cannot interpret %s %s as seconds.' % (
seconds, type(seconds)))
if not isinstance(micros, integer_types + (float,)):
raise TypeError('Cannot interpret %s %s as micros.' % (
micros, type(micros)))
self.micros = int(seconds * 1000000) + int(micros)
@staticmethod
def of(seconds):
"""Return the Timestamp for the given number of seconds.
If the input is already a Timestamp, the input itself will be returned.
Args:
seconds: Number of seconds as int, float, long, or Timestamp.
Returns:
Corresponding Timestamp object.
"""
if not isinstance(seconds, integer_types + (float, Timestamp)):
raise TypeError('Cannot interpret %s %s as Timestamp.' % (
seconds, type(seconds)))
if isinstance(seconds, Timestamp):
return seconds
return Timestamp(seconds)
RFC_3339_RE = re.compile(
r'^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.(\d+))?Z$')
@staticmethod
def _epoch_datetime_utc():
return datetime.datetime.fromtimestamp(0, pytz.utc)
@classmethod
def from_utc_datetime(cls, dt):
"""Create a ``Timestamp`` instance from a ``datetime.datetime`` object.
Args:
dt: A ``datetime.datetime`` object in UTC (offset-aware).
"""
if dt.tzinfo != pytz.utc:
raise ValueError('dt not in UTC: %s', dt)
duration = dt - cls._epoch_datetime_utc()
return Timestamp(duration.total_seconds())
@classmethod
def from_rfc3339(cls, rfc3339):
"""Create a ``Timestamp`` instance from an RFC 3339 compliant string.
Args:
rfc3339: String in RFC 3339 form.
"""
dt_args = []
match = cls.RFC_3339_RE.match(rfc3339)
if match is None:
raise ValueError('Could not parse RFC 3339 string: %s', rfc3339)
for s in match.groups():
if s is not None:
dt_args.append(int(s))
else:
dt_args.append(0)
dt_args += (pytz.utc, )
dt = datetime.datetime(*dt_args)
return cls.from_utc_datetime(dt)
def predecessor(self):
"""Returns the largest timestamp smaller than self."""
return Timestamp(micros=self.micros - 1)
def __repr__(self):
micros = self.micros
sign = ''
if micros < 0:
sign = '-'
micros = -micros
int_part = micros // 1000000
frac_part = micros % 1000000
if frac_part:
return 'Timestamp(%s%d.%06d)' % (sign, int_part, frac_part)
return 'Timestamp(%s%d)' % (sign, int_part)
def to_utc_datetime(self):
# We can't easily construct a datetime object from microseconds, so we
# create one at the epoch and add an appropriate timedelta interval.
return self._epoch_datetime_utc().replace(tzinfo=None) + datetime.timedelta(
microseconds=self.micros)
def to_rfc3339(self):
# Append 'Z' for UTC timezone.
return self.to_utc_datetime().isoformat() + 'Z'
def __float__(self):
# Note that the returned value may have lost precision.
return self.micros / 1000000
def __int__(self):
# Note that the returned value may have lost precision.
return self.micros // 1000000
def __cmp__(self, other):
# Allow comparisons between Duration and Timestamp values.
if not isinstance(other, Duration):
other = Timestamp.of(other)
return cmp(self.micros, other.micros)
def __hash__(self):
return hash(self.micros)
def __add__(self, other):
other = Duration.of(other)
return Timestamp(micros=self.micros + other.micros)
def __radd__(self, other):
return self + other
def __sub__(self, other):
other = Duration.of(other)
return Timestamp(micros=self.micros - other.micros)
def __mod__(self, other):
other = Duration.of(other)
return Duration(micros=self.micros % other.micros)
MIN_TIMESTAMP = Timestamp(micros=-0x7fffffffffffffff - 1)
MAX_TIMESTAMP = Timestamp(micros=0x7fffffffffffffff)
class Duration(object):
"""Represents a second duration with microsecond granularity.
Can be treated in common arithmetic operations as a numeric type.
Internally stores a time interval as an int of microseconds. This strategy
is necessary since floating point values lose precision when storing values,
especially after arithmetic operations (for example, 10000000 % 0.1 evaluates
to 0.0999999994448885).
"""
def __init__(self, seconds=0, micros=0):
self.micros = int(seconds * 1000000) + int(micros)
@staticmethod
def of(seconds):
"""Return the Duration for the given number of seconds since Unix epoch.
If the input is already a Duration, the input itself will be returned.
Args:
seconds: Number of seconds as int, float or Duration.
Returns:
Corresponding Duration object.
"""
if isinstance(seconds, Timestamp):
raise TypeError('Cannot interpret %s as Duration.' % seconds)
if isinstance(seconds, Duration):
return seconds
return Duration(seconds)
def __repr__(self):
micros = self.micros
sign = ''
if micros < 0:
sign = '-'
micros = -micros
int_part = micros // 1000000
frac_part = micros % 1000000
if frac_part:
return 'Duration(%s%d.%06d)' % (sign, int_part, frac_part)
return 'Duration(%s%d)' % (sign, int_part)
def __float__(self):
# Note that the returned value may have lost precision.
return self.micros / 1000000
def __cmp__(self, other):
# Allow comparisons between Duration and Timestamp values.
if not isinstance(other, Timestamp):
other = Duration.of(other)
return cmp(self.micros, other.micros)
def __hash__(self):
return hash(self.micros)
def __neg__(self):
return Duration(micros=-self.micros)
def __add__(self, other):
if isinstance(other, Timestamp):
return other + self
other = Duration.of(other)
return Duration(micros=self.micros + other.micros)
def __radd__(self, other):
return self + other
def __sub__(self, other):
other = Duration.of(other)
return Duration(micros=self.micros - other.micros)
def __rsub__(self, other):
return -(self - other)
def __mul__(self, other):
other = Duration.of(other)
return Duration(micros=self.micros * other.micros // 1000000)
def __rmul__(self, other):
return self * other
def __mod__(self, other):
other = Duration.of(other)
return Duration(micros=self.micros % other.micros)
# The minimum granularity / interval expressible in a Timestamp / Duration
# object.
TIME_GRANULARITY = Duration(micros=1)