content: /**
   * 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.
   */
  package com.alibaba.jstorm.window;
  
  import backtype.storm.task.TopologyContext;
  import java.io.Serializable;
  import java.util.Collection;
  
  /**
   * @author wange
   * @since 16/12/8
   */
  public abstract class WindowAssigner<T> implements Serializable {
      private static final long serialVersionUID = 1L;
  
      /**
       * Returns a {@code Collection} of windows that should be assigned to the element.
       *
       * @param element   The element to which windows should be assigned.
       * @param timestamp The timestamp of the element.
       */
      public abstract Collection<TimeWindow> assignWindows(T element, long timestamp);
  
      /**
       * Returns the default trigger associated with this {@code WindowAssigner}.
       */
      public abstract Trigger<T> getDefaultTrigger(TopologyContext topologyContext);
  
      public static boolean isEventTime(WindowAssigner windowAssigner) {
          return windowAssigner instanceof SlidingEventTimeWindows ||
                  windowAssigner instanceof TumblingEventTimeWindows ||
                  windowAssigner instanceof EventTimeSessionWindows;
      }
  
      public static boolean isProcessingTime(WindowAssigner windowAssigner) {
          return windowAssigner instanceof SlidingProcessingTimeWindows ||
                  windowAssigner instanceof TumblingProcessingTimeWindows ||
                  windowAssigner instanceof ProcessingTimeSessionWindows;
      }
  
      public static boolean isSessionTime(WindowAssigner windowAssigner) {
          return windowAssigner instanceof ProcessingTimeSessionWindows ||
                  windowAssigner instanceof EventTimeSessionWindows;
      }
  
      public static boolean isIngestionTime(WindowAssigner windowAssigner) {
          return windowAssigner instanceof TumblingIngestionTimeWindows ||
                  windowAssigner instanceof SlidingIngestionTimeWindows;
      }
  
  }
  