Source code for apache_beam.runners.direct.clock

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

from __future__ import absolute_import

import time


class Clock(object):
  """For internal use only; no backwards-compatibility guarantees."""

  def time(self):
    """Returns the number of milliseconds since epoch."""
    return int(time.time() * 1000)


class MockClock(Clock):
  """For internal use only; no backwards-compatibility guarantees.

  Mock clock implementation for testing."""

  def __init__(self, now_in_ms):
    self._now_in_ms = now_in_ms

  def time(self):
    return self._now_in_ms

  def set_time(self, value_in_ms):
    assert value_in_ms >= self._now_in_ms
    self._now_in_ms = value_in_ms

  def advance(self, duration_in_ms):
    assert duration_in_ms >= 0
    self._now_in_ms += duration_in_ms