code: /*
   * 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 org.apache.skywalking.oap.server.library.datacarrier.common;
  
  import java.io.Serializable;
  import java.util.concurrent.atomic.AtomicIntegerArray;
  
  public class AtomicRangeInteger extends Number implements Serializable {
      private static final long serialVersionUID = -4099792402691141643L;
      private AtomicIntegerArray values;
  
      private static final int VALUE_OFFSET = 15;
  
      private int startValue;
      private int endValue;
  
      public AtomicRangeInteger(int startValue, int maxValue) {
          this.values = new AtomicIntegerArray(31);
          this.values.set(VALUE_OFFSET, startValue);
          this.startValue = startValue;
          this.endValue = maxValue - 1;
      }
  
      public final int getAndIncrement() {
          int next;
          do {
              next = this.values.incrementAndGet(VALUE_OFFSET);
              if (next > endValue && this.values.compareAndSet(VALUE_OFFSET, next, startValue)) {
                  return endValue;
              }
          }
          while (next > endValue);
  
          return next - 1;
      }
  
      public final int get() {
          return this.values.get(VALUE_OFFSET);
      }
  
      @Override
      public int intValue() {
          return this.values.get(VALUE_OFFSET);
      }
  
      @Override
      public long longValue() {
          return this.values.get(VALUE_OFFSET);
      }
  
      @Override
      public float floatValue() {
          return this.values.get(VALUE_OFFSET);
      }
  
      @Override
      public double doubleValue() {
          return this.values.get(VALUE_OFFSET);
      }
  }
  