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 backtype.storm.tuple.Tuple;
  import backtype.storm.tuple.TupleImpl;
  import com.google.common.collect.Lists;
  import java.util.Collection;
  
  /**
   * A {@link WindowAssigner} that assigns all elements to the same global window.
   */
  public class TumblingCountWindows<T> extends WindowAssigner<T> {
      private static final long serialVersionUID = 1L;
  
      private final long size;
  
      private long offset = -1;
  
      private TumblingCountWindows(long size) {
          this.size = size;
      }
  
      @Override
      public Collection<TimeWindow> assignWindows(T element, long timestamp) {
          offset++;
  
          long start = offset / size * size;
          return Lists.newArrayList(new TimeWindow(start, start + size));
      }
  
      @Override
      public Trigger<T> getDefaultTrigger(TopologyContext topologyContext) {
          return CountTrigger.of(size);
      }
  
      @Override
      public String toString() {
          return "GlobalWindows()";
      }
  
      /**
       * Creates a new {@code GlobalWindows} {@link WindowAssigner} that assigns
       * all elements to the same {@link GlobalWindow}.
       *
       * @return The global window policy.
       */
      public static <T> TumblingCountWindows<T> create(long size) {
          return new TumblingCountWindows<>(size);
      }
  
      public static void main(String[] args) {
          // o o o o o o o o o o
          // 0 1 2 3 4 5 6 7 8 9
          TumblingCountWindows<Tuple> slideCountAssigner = TumblingCountWindows.create(3);
          for (int i = 0; i < 10; i++) {
              System.out.println("i=" + i);
              Collection<TimeWindow> windows = slideCountAssigner.assignWindows(new TupleImpl(), 0);
              for (TimeWindow window : windows) {
                  System.out.println(window);
              }
              System.out.println();
          }
      }
  }
  