heronpy/streamlet/windowconfig.py

#!/usr/bin/env python3
# -*- encoding: utf-8 -*-

#  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.

'''windowconfig.py: module for defining windowconfig'''

import datetime

class WindowConfig(object):
  """WindowConfig allows streamlet API users to program window configuration for operations
     that rely on windowing. Currently we only support time/count based
     sliding/tumbling windows.
  """
  def __init__(self, window_duration, slide_interval):
    self._window_duration = window_duration
    self._slide_interval = slide_interval
    if self._window_duration.microseconds > 0 or self._slide_interval.microseconds > 0:
      raise RuntimeError("Python Windowing curently only supports second resolution")

  @staticmethod
  def create_tumbling_window(window_duration):
    return WindowConfig(window_duration, window_duration)

  @staticmethod
  def create_sliding_window(window_duration, slide_interval):
    if isinstance(window_duration, int):
      window_duration = datetime.timedelta(seconds=window_duration)
    if isinstance(slide_interval, int):
      slide_interval = datetime.timedelta(seconds=slide_interval)
    if not isinstance(window_duration, datetime.timedelta):
      raise RuntimeError("Window Duration has to be of type datetime.timedelta")
    if not isinstance(slide_interval, datetime.timedelta):
      raise RuntimeError("Slide Interval has to be of type datetime.timedelta")
    return WindowConfig(window_duration, slide_interval)