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 backtype.storm.utils;
  
  public class WindowedTimeThrottler {
      long _windowMillis;
      int _maxAmt;
      long _windowStartTime;
      int _windowEvents = 0;
  
      public WindowedTimeThrottler(Number windowMillis, Number maxAmt) {
          _windowMillis = windowMillis.longValue();
          _maxAmt = maxAmt.intValue();
          _windowStartTime = System.currentTimeMillis();
      }
  
      public boolean isThrottled() {
          resetIfNecessary();
          return _windowEvents >= _maxAmt;
      }
  
      // returns void if the event should continue, false if the event should not be done
      public void markEvent() {
          resetIfNecessary();
          _windowEvents++;
  
      }
  
      private void resetIfNecessary() {
          long now = System.currentTimeMillis();
          if (now - _windowStartTime > _windowMillis) {
              _windowStartTime = now;
              _windowEvents = 0;
          }
      }
  }
  