sdks/python/apache_beam/runners/direct/clock.py

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#    http://www.apache.org/licenses/LICENSE-2.0
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"""Clock implementations for real time processing and testing.

For internal use only. No backwards compatibility guarantees.
"""
from __future__ import absolute_import

import time
from builtins import object


class Clock(object):
  def time(self):
    """Returns the number of seconds since epoch."""
    raise NotImplementedError()

  def advance_time(self, advance_by):
    """Advances the clock by a number of seconds."""
    raise NotImplementedError()


class RealClock(object):
  def time(self):
    return time.time()


class TestClock(object):
  """Clock used for Testing"""
  def __init__(self, current_time=0):
    self._current_time = current_time

  def time(self):
    return self._current_time

  def advance_time(self, advance_by):
    self._current_time += advance_by